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linux-zen-server/drivers/net/ethernet/chelsio/cxgb4vf/sge.c

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/*
* This file is part of the Chelsio T4 PCI-E SR-IOV Virtual Function Ethernet
* driver for Linux.
*
* Copyright (c) 2009-2010 Chelsio Communications, Inc. All rights reserved.
*
* This software is available to you under a choice of one of two
* licenses. You may choose to be licensed under the terms of the GNU
* General Public License (GPL) Version 2, available from the file
* COPYING in the main directory of this source tree, or the
* OpenIB.org BSD license below:
*
* Redistribution and use in source and binary forms, with or
* without modification, are permitted provided that the following
* conditions are met:
*
* - Redistributions of source code must retain the above
* copyright notice, this list of conditions and the following
* disclaimer.
*
* - Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials
* provided with the distribution.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
#include <linux/skbuff.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/if_vlan.h>
#include <linux/ip.h>
#include <net/ipv6.h>
#include <net/tcp.h>
#include <linux/dma-mapping.h>
#include <linux/prefetch.h>
#include "t4vf_common.h"
#include "t4vf_defs.h"
#include "../cxgb4/t4_regs.h"
#include "../cxgb4/t4_values.h"
#include "../cxgb4/t4fw_api.h"
#include "../cxgb4/t4_msg.h"
/*
* Constants ...
*/
enum {
/*
* Egress Queue sizes, producer and consumer indices are all in units
* of Egress Context Units bytes. Note that as far as the hardware is
* concerned, the free list is an Egress Queue (the host produces free
* buffers which the hardware consumes) and free list entries are
* 64-bit PCI DMA addresses.
*/
EQ_UNIT = SGE_EQ_IDXSIZE,
FL_PER_EQ_UNIT = EQ_UNIT / sizeof(__be64),
TXD_PER_EQ_UNIT = EQ_UNIT / sizeof(__be64),
/*
* Max number of TX descriptors we clean up at a time. Should be
* modest as freeing skbs isn't cheap and it happens while holding
* locks. We just need to free packets faster than they arrive, we
* eventually catch up and keep the amortized cost reasonable.
*/
MAX_TX_RECLAIM = 16,
/*
* Max number of Rx buffers we replenish at a time. Again keep this
* modest, allocating buffers isn't cheap either.
*/
MAX_RX_REFILL = 16,
/*
* Period of the Rx queue check timer. This timer is infrequent as it
* has something to do only when the system experiences severe memory
* shortage.
*/
RX_QCHECK_PERIOD = (HZ / 2),
/*
* Period of the TX queue check timer and the maximum number of TX
* descriptors to be reclaimed by the TX timer.
*/
TX_QCHECK_PERIOD = (HZ / 2),
MAX_TIMER_TX_RECLAIM = 100,
/*
* Suspend an Ethernet TX queue with fewer available descriptors than
* this. We always want to have room for a maximum sized packet:
* inline immediate data + MAX_SKB_FRAGS. This is the same as
* calc_tx_flits() for a TSO packet with nr_frags == MAX_SKB_FRAGS
* (see that function and its helpers for a description of the
* calculation).
*/
ETHTXQ_MAX_FRAGS = MAX_SKB_FRAGS + 1,
ETHTXQ_MAX_SGL_LEN = ((3 * (ETHTXQ_MAX_FRAGS-1))/2 +
((ETHTXQ_MAX_FRAGS-1) & 1) +
2),
ETHTXQ_MAX_HDR = (sizeof(struct fw_eth_tx_pkt_vm_wr) +
sizeof(struct cpl_tx_pkt_lso_core) +
sizeof(struct cpl_tx_pkt_core)) / sizeof(__be64),
ETHTXQ_MAX_FLITS = ETHTXQ_MAX_SGL_LEN + ETHTXQ_MAX_HDR,
ETHTXQ_STOP_THRES = 1 + DIV_ROUND_UP(ETHTXQ_MAX_FLITS, TXD_PER_EQ_UNIT),
/*
* Max TX descriptor space we allow for an Ethernet packet to be
* inlined into a WR. This is limited by the maximum value which
* we can specify for immediate data in the firmware Ethernet TX
* Work Request.
*/
MAX_IMM_TX_PKT_LEN = FW_WR_IMMDLEN_M,
/*
* Max size of a WR sent through a control TX queue.
*/
MAX_CTRL_WR_LEN = 256,
/*
* Maximum amount of data which we'll ever need to inline into a
* TX ring: max(MAX_IMM_TX_PKT_LEN, MAX_CTRL_WR_LEN).
*/
MAX_IMM_TX_LEN = (MAX_IMM_TX_PKT_LEN > MAX_CTRL_WR_LEN
? MAX_IMM_TX_PKT_LEN
: MAX_CTRL_WR_LEN),
/*
* For incoming packets less than RX_COPY_THRES, we copy the data into
* an skb rather than referencing the data. We allocate enough
* in-line room in skb's to accommodate pulling in RX_PULL_LEN bytes
* of the data (header).
*/
RX_COPY_THRES = 256,
RX_PULL_LEN = 128,
/*
* Main body length for sk_buffs used for RX Ethernet packets with
* fragments. Should be >= RX_PULL_LEN but possibly bigger to give
* pskb_may_pull() some room.
*/
RX_SKB_LEN = 512,
};
/*
* Software state per TX descriptor.
*/
struct tx_sw_desc {
struct sk_buff *skb; /* socket buffer of TX data source */
struct ulptx_sgl *sgl; /* scatter/gather list in TX Queue */
};
/*
* Software state per RX Free List descriptor. We keep track of the allocated
* FL page, its size, and its PCI DMA address (if the page is mapped). The FL
* page size and its PCI DMA mapped state are stored in the low bits of the
* PCI DMA address as per below.
*/
struct rx_sw_desc {
struct page *page; /* Free List page buffer */
dma_addr_t dma_addr; /* PCI DMA address (if mapped) */
/* and flags (see below) */
};
/*
* The low bits of rx_sw_desc.dma_addr have special meaning. Note that the
* SGE also uses the low 4 bits to determine the size of the buffer. It uses
* those bits to index into the SGE_FL_BUFFER_SIZE[index] register array.
* Since we only use SGE_FL_BUFFER_SIZE0 and SGE_FL_BUFFER_SIZE1, these low 4
* bits can only contain a 0 or a 1 to indicate which size buffer we're giving
* to the SGE. Thus, our software state of "is the buffer mapped for DMA" is
* maintained in an inverse sense so the hardware never sees that bit high.
*/
enum {
RX_LARGE_BUF = 1 << 0, /* buffer is SGE_FL_BUFFER_SIZE[1] */
RX_UNMAPPED_BUF = 1 << 1, /* buffer is not mapped */
};
/**
* get_buf_addr - return DMA buffer address of software descriptor
* @sdesc: pointer to the software buffer descriptor
*
* Return the DMA buffer address of a software descriptor (stripping out
* our low-order flag bits).
*/
static inline dma_addr_t get_buf_addr(const struct rx_sw_desc *sdesc)
{
return sdesc->dma_addr & ~(dma_addr_t)(RX_LARGE_BUF | RX_UNMAPPED_BUF);
}
/**
* is_buf_mapped - is buffer mapped for DMA?
* @sdesc: pointer to the software buffer descriptor
*
* Determine whether the buffer associated with a software descriptor in
* mapped for DMA or not.
*/
static inline bool is_buf_mapped(const struct rx_sw_desc *sdesc)
{
return !(sdesc->dma_addr & RX_UNMAPPED_BUF);
}
/**
* need_skb_unmap - does the platform need unmapping of sk_buffs?
*
* Returns true if the platform needs sk_buff unmapping. The compiler
* optimizes away unnecessary code if this returns true.
*/
static inline int need_skb_unmap(void)
{
#ifdef CONFIG_NEED_DMA_MAP_STATE
return 1;
#else
return 0;
#endif
}
/**
* txq_avail - return the number of available slots in a TX queue
* @tq: the TX queue
*
* Returns the number of available descriptors in a TX queue.
*/
static inline unsigned int txq_avail(const struct sge_txq *tq)
{
return tq->size - 1 - tq->in_use;
}
/**
* fl_cap - return the capacity of a Free List
* @fl: the Free List
*
* Returns the capacity of a Free List. The capacity is less than the
* size because an Egress Queue Index Unit worth of descriptors needs to
* be left unpopulated, otherwise the Producer and Consumer indices PIDX
* and CIDX will match and the hardware will think the FL is empty.
*/
static inline unsigned int fl_cap(const struct sge_fl *fl)
{
return fl->size - FL_PER_EQ_UNIT;
}
/**
* fl_starving - return whether a Free List is starving.
* @adapter: pointer to the adapter
* @fl: the Free List
*
* Tests specified Free List to see whether the number of buffers
* available to the hardware has falled below our "starvation"
* threshold.
*/
static inline bool fl_starving(const struct adapter *adapter,
const struct sge_fl *fl)
{
const struct sge *s = &adapter->sge;
return fl->avail - fl->pend_cred <= s->fl_starve_thres;
}
/**
* map_skb - map an skb for DMA to the device
* @dev: the egress net device
* @skb: the packet to map
* @addr: a pointer to the base of the DMA mapping array
*
* Map an skb for DMA to the device and return an array of DMA addresses.
*/
static int map_skb(struct device *dev, const struct sk_buff *skb,
dma_addr_t *addr)
{
const skb_frag_t *fp, *end;
const struct skb_shared_info *si;
*addr = dma_map_single(dev, skb->data, skb_headlen(skb), DMA_TO_DEVICE);
if (dma_mapping_error(dev, *addr))
goto out_err;
si = skb_shinfo(skb);
end = &si->frags[si->nr_frags];
for (fp = si->frags; fp < end; fp++) {
*++addr = skb_frag_dma_map(dev, fp, 0, skb_frag_size(fp),
DMA_TO_DEVICE);
if (dma_mapping_error(dev, *addr))
goto unwind;
}
return 0;
unwind:
while (fp-- > si->frags)
dma_unmap_page(dev, *--addr, skb_frag_size(fp), DMA_TO_DEVICE);
dma_unmap_single(dev, addr[-1], skb_headlen(skb), DMA_TO_DEVICE);
out_err:
return -ENOMEM;
}
static void unmap_sgl(struct device *dev, const struct sk_buff *skb,
const struct ulptx_sgl *sgl, const struct sge_txq *tq)
{
const struct ulptx_sge_pair *p;
unsigned int nfrags = skb_shinfo(skb)->nr_frags;
if (likely(skb_headlen(skb)))
dma_unmap_single(dev, be64_to_cpu(sgl->addr0),
be32_to_cpu(sgl->len0), DMA_TO_DEVICE);
else {
dma_unmap_page(dev, be64_to_cpu(sgl->addr0),
be32_to_cpu(sgl->len0), DMA_TO_DEVICE);
nfrags--;
}
/*
* the complexity below is because of the possibility of a wrap-around
* in the middle of an SGL
*/
for (p = sgl->sge; nfrags >= 2; nfrags -= 2) {
if (likely((u8 *)(p + 1) <= (u8 *)tq->stat)) {
unmap:
dma_unmap_page(dev, be64_to_cpu(p->addr[0]),
be32_to_cpu(p->len[0]), DMA_TO_DEVICE);
dma_unmap_page(dev, be64_to_cpu(p->addr[1]),
be32_to_cpu(p->len[1]), DMA_TO_DEVICE);
p++;
} else if ((u8 *)p == (u8 *)tq->stat) {
p = (const struct ulptx_sge_pair *)tq->desc;
goto unmap;
} else if ((u8 *)p + 8 == (u8 *)tq->stat) {
const __be64 *addr = (const __be64 *)tq->desc;
dma_unmap_page(dev, be64_to_cpu(addr[0]),
be32_to_cpu(p->len[0]), DMA_TO_DEVICE);
dma_unmap_page(dev, be64_to_cpu(addr[1]),
be32_to_cpu(p->len[1]), DMA_TO_DEVICE);
p = (const struct ulptx_sge_pair *)&addr[2];
} else {
const __be64 *addr = (const __be64 *)tq->desc;
dma_unmap_page(dev, be64_to_cpu(p->addr[0]),
be32_to_cpu(p->len[0]), DMA_TO_DEVICE);
dma_unmap_page(dev, be64_to_cpu(addr[0]),
be32_to_cpu(p->len[1]), DMA_TO_DEVICE);
p = (const struct ulptx_sge_pair *)&addr[1];
}
}
if (nfrags) {
__be64 addr;
if ((u8 *)p == (u8 *)tq->stat)
p = (const struct ulptx_sge_pair *)tq->desc;
addr = ((u8 *)p + 16 <= (u8 *)tq->stat
? p->addr[0]
: *(const __be64 *)tq->desc);
dma_unmap_page(dev, be64_to_cpu(addr), be32_to_cpu(p->len[0]),
DMA_TO_DEVICE);
}
}
/**
* free_tx_desc - reclaims TX descriptors and their buffers
* @adapter: the adapter
* @tq: the TX queue to reclaim descriptors from
* @n: the number of descriptors to reclaim
* @unmap: whether the buffers should be unmapped for DMA
*
* Reclaims TX descriptors from an SGE TX queue and frees the associated
* TX buffers. Called with the TX queue lock held.
*/
static void free_tx_desc(struct adapter *adapter, struct sge_txq *tq,
unsigned int n, bool unmap)
{
struct tx_sw_desc *sdesc;
unsigned int cidx = tq->cidx;
struct device *dev = adapter->pdev_dev;
const int need_unmap = need_skb_unmap() && unmap;
sdesc = &tq->sdesc[cidx];
while (n--) {
/*
* If we kept a reference to the original TX skb, we need to
* unmap it from PCI DMA space (if required) and free it.
*/
if (sdesc->skb) {
if (need_unmap)
unmap_sgl(dev, sdesc->skb, sdesc->sgl, tq);
dev_consume_skb_any(sdesc->skb);
sdesc->skb = NULL;
}
sdesc++;
if (++cidx == tq->size) {
cidx = 0;
sdesc = tq->sdesc;
}
}
tq->cidx = cidx;
}
/*
* Return the number of reclaimable descriptors in a TX queue.
*/
static inline int reclaimable(const struct sge_txq *tq)
{
int hw_cidx = be16_to_cpu(tq->stat->cidx);
int reclaimable = hw_cidx - tq->cidx;
if (reclaimable < 0)
reclaimable += tq->size;
return reclaimable;
}
/**
* reclaim_completed_tx - reclaims completed TX descriptors
* @adapter: the adapter
* @tq: the TX queue to reclaim completed descriptors from
* @unmap: whether the buffers should be unmapped for DMA
*
* Reclaims TX descriptors that the SGE has indicated it has processed,
* and frees the associated buffers if possible. Called with the TX
* queue locked.
*/
static inline void reclaim_completed_tx(struct adapter *adapter,
struct sge_txq *tq,
bool unmap)
{
int avail = reclaimable(tq);
if (avail) {
/*
* Limit the amount of clean up work we do at a time to keep
* the TX lock hold time O(1).
*/
if (avail > MAX_TX_RECLAIM)
avail = MAX_TX_RECLAIM;
free_tx_desc(adapter, tq, avail, unmap);
tq->in_use -= avail;
}
}
/**
* get_buf_size - return the size of an RX Free List buffer.
* @adapter: pointer to the associated adapter
* @sdesc: pointer to the software buffer descriptor
*/
static inline int get_buf_size(const struct adapter *adapter,
const struct rx_sw_desc *sdesc)
{
const struct sge *s = &adapter->sge;
return (s->fl_pg_order > 0 && (sdesc->dma_addr & RX_LARGE_BUF)
? (PAGE_SIZE << s->fl_pg_order) : PAGE_SIZE);
}
/**
* free_rx_bufs - free RX buffers on an SGE Free List
* @adapter: the adapter
* @fl: the SGE Free List to free buffers from
* @n: how many buffers to free
*
* Release the next @n buffers on an SGE Free List RX queue. The
* buffers must be made inaccessible to hardware before calling this
* function.
*/
static void free_rx_bufs(struct adapter *adapter, struct sge_fl *fl, int n)
{
while (n--) {
struct rx_sw_desc *sdesc = &fl->sdesc[fl->cidx];
if (is_buf_mapped(sdesc))
dma_unmap_page(adapter->pdev_dev, get_buf_addr(sdesc),
get_buf_size(adapter, sdesc),
DMA_FROM_DEVICE);
put_page(sdesc->page);
sdesc->page = NULL;
if (++fl->cidx == fl->size)
fl->cidx = 0;
fl->avail--;
}
}
/**
* unmap_rx_buf - unmap the current RX buffer on an SGE Free List
* @adapter: the adapter
* @fl: the SGE Free List
*
* Unmap the current buffer on an SGE Free List RX queue. The
* buffer must be made inaccessible to HW before calling this function.
*
* This is similar to @free_rx_bufs above but does not free the buffer.
* Do note that the FL still loses any further access to the buffer.
* This is used predominantly to "transfer ownership" of an FL buffer
* to another entity (typically an skb's fragment list).
*/
static void unmap_rx_buf(struct adapter *adapter, struct sge_fl *fl)
{
struct rx_sw_desc *sdesc = &fl->sdesc[fl->cidx];
if (is_buf_mapped(sdesc))
dma_unmap_page(adapter->pdev_dev, get_buf_addr(sdesc),
get_buf_size(adapter, sdesc),
DMA_FROM_DEVICE);
sdesc->page = NULL;
if (++fl->cidx == fl->size)
fl->cidx = 0;
fl->avail--;
}
/**
* ring_fl_db - righ doorbell on free list
* @adapter: the adapter
* @fl: the Free List whose doorbell should be rung ...
*
* Tell the Scatter Gather Engine that there are new free list entries
* available.
*/
static inline void ring_fl_db(struct adapter *adapter, struct sge_fl *fl)
{
u32 val = adapter->params.arch.sge_fl_db;
/* The SGE keeps track of its Producer and Consumer Indices in terms
* of Egress Queue Units so we can only tell it about integral numbers
* of multiples of Free List Entries per Egress Queue Units ...
*/
if (fl->pend_cred >= FL_PER_EQ_UNIT) {
if (is_t4(adapter->params.chip))
val |= PIDX_V(fl->pend_cred / FL_PER_EQ_UNIT);
else
val |= PIDX_T5_V(fl->pend_cred / FL_PER_EQ_UNIT);
/* Make sure all memory writes to the Free List queue are
* committed before we tell the hardware about them.
*/
wmb();
/* If we don't have access to the new User Doorbell (T5+), use
* the old doorbell mechanism; otherwise use the new BAR2
* mechanism.
*/
if (unlikely(fl->bar2_addr == NULL)) {
t4_write_reg(adapter,
T4VF_SGE_BASE_ADDR + SGE_VF_KDOORBELL,
QID_V(fl->cntxt_id) | val);
} else {
writel(val | QID_V(fl->bar2_qid),
fl->bar2_addr + SGE_UDB_KDOORBELL);
/* This Write memory Barrier will force the write to
* the User Doorbell area to be flushed.
*/
wmb();
}
fl->pend_cred %= FL_PER_EQ_UNIT;
}
}
/**
* set_rx_sw_desc - initialize software RX buffer descriptor
* @sdesc: pointer to the softwore RX buffer descriptor
* @page: pointer to the page data structure backing the RX buffer
* @dma_addr: PCI DMA address (possibly with low-bit flags)
*/
static inline void set_rx_sw_desc(struct rx_sw_desc *sdesc, struct page *page,
dma_addr_t dma_addr)
{
sdesc->page = page;
sdesc->dma_addr = dma_addr;
}
/*
* Support for poisoning RX buffers ...
*/
#define POISON_BUF_VAL -1
static inline void poison_buf(struct page *page, size_t sz)
{
#if POISON_BUF_VAL >= 0
memset(page_address(page), POISON_BUF_VAL, sz);
#endif
}
/**
* refill_fl - refill an SGE RX buffer ring
* @adapter: the adapter
* @fl: the Free List ring to refill
* @n: the number of new buffers to allocate
* @gfp: the gfp flags for the allocations
*
* (Re)populate an SGE free-buffer queue with up to @n new packet buffers,
* allocated with the supplied gfp flags. The caller must assure that
* @n does not exceed the queue's capacity -- i.e. (cidx == pidx) _IN
* EGRESS QUEUE UNITS_ indicates an empty Free List! Returns the number
* of buffers allocated. If afterwards the queue is found critically low,
* mark it as starving in the bitmap of starving FLs.
*/
static unsigned int refill_fl(struct adapter *adapter, struct sge_fl *fl,
int n, gfp_t gfp)
{
struct sge *s = &adapter->sge;
struct page *page;
dma_addr_t dma_addr;
unsigned int cred = fl->avail;
__be64 *d = &fl->desc[fl->pidx];
struct rx_sw_desc *sdesc = &fl->sdesc[fl->pidx];
/*
* Sanity: ensure that the result of adding n Free List buffers
* won't result in wrapping the SGE's Producer Index around to
* it's Consumer Index thereby indicating an empty Free List ...
*/
BUG_ON(fl->avail + n > fl->size - FL_PER_EQ_UNIT);
gfp |= __GFP_NOWARN;
/*
* If we support large pages, prefer large buffers and fail over to
* small pages if we can't allocate large pages to satisfy the refill.
* If we don't support large pages, drop directly into the small page
* allocation code.
*/
if (s->fl_pg_order == 0)
goto alloc_small_pages;
while (n) {
page = __dev_alloc_pages(gfp, s->fl_pg_order);
if (unlikely(!page)) {
/*
* We've failed inour attempt to allocate a "large
* page". Fail over to the "small page" allocation
* below.
*/
fl->large_alloc_failed++;
break;
}
poison_buf(page, PAGE_SIZE << s->fl_pg_order);
dma_addr = dma_map_page(adapter->pdev_dev, page, 0,
PAGE_SIZE << s->fl_pg_order,
DMA_FROM_DEVICE);
if (unlikely(dma_mapping_error(adapter->pdev_dev, dma_addr))) {
/*
* We've run out of DMA mapping space. Free up the
* buffer and return with what we've managed to put
* into the free list. We don't want to fail over to
* the small page allocation below in this case
* because DMA mapping resources are typically
* critical resources once they become scarse.
*/
__free_pages(page, s->fl_pg_order);
goto out;
}
dma_addr |= RX_LARGE_BUF;
*d++ = cpu_to_be64(dma_addr);
set_rx_sw_desc(sdesc, page, dma_addr);
sdesc++;
fl->avail++;
if (++fl->pidx == fl->size) {
fl->pidx = 0;
sdesc = fl->sdesc;
d = fl->desc;
}
n--;
}
alloc_small_pages:
while (n--) {
page = __dev_alloc_page(gfp);
if (unlikely(!page)) {
fl->alloc_failed++;
break;
}
poison_buf(page, PAGE_SIZE);
dma_addr = dma_map_page(adapter->pdev_dev, page, 0, PAGE_SIZE,
DMA_FROM_DEVICE);
if (unlikely(dma_mapping_error(adapter->pdev_dev, dma_addr))) {
put_page(page);
break;
}
*d++ = cpu_to_be64(dma_addr);
set_rx_sw_desc(sdesc, page, dma_addr);
sdesc++;
fl->avail++;
if (++fl->pidx == fl->size) {
fl->pidx = 0;
sdesc = fl->sdesc;
d = fl->desc;
}
}
out:
/*
* Update our accounting state to incorporate the new Free List
* buffers, tell the hardware about them and return the number of
* buffers which we were able to allocate.
*/
cred = fl->avail - cred;
fl->pend_cred += cred;
ring_fl_db(adapter, fl);
if (unlikely(fl_starving(adapter, fl))) {
smp_wmb();
set_bit(fl->cntxt_id, adapter->sge.starving_fl);
}
return cred;
}
/*
* Refill a Free List to its capacity or the Maximum Refill Increment,
* whichever is smaller ...
*/
static inline void __refill_fl(struct adapter *adapter, struct sge_fl *fl)
{
refill_fl(adapter, fl,
min((unsigned int)MAX_RX_REFILL, fl_cap(fl) - fl->avail),
GFP_ATOMIC);
}
/**
* alloc_ring - allocate resources for an SGE descriptor ring
* @dev: the PCI device's core device
* @nelem: the number of descriptors
* @hwsize: the size of each hardware descriptor
* @swsize: the size of each software descriptor
* @busaddrp: the physical PCI bus address of the allocated ring
* @swringp: return address pointer for software ring
* @stat_size: extra space in hardware ring for status information
*
* Allocates resources for an SGE descriptor ring, such as TX queues,
* free buffer lists, response queues, etc. Each SGE ring requires
* space for its hardware descriptors plus, optionally, space for software
* state associated with each hardware entry (the metadata). The function
* returns three values: the virtual address for the hardware ring (the
* return value of the function), the PCI bus address of the hardware
* ring (in *busaddrp), and the address of the software ring (in swringp).
* Both the hardware and software rings are returned zeroed out.
*/
static void *alloc_ring(struct device *dev, size_t nelem, size_t hwsize,
size_t swsize, dma_addr_t *busaddrp, void *swringp,
size_t stat_size)
{
/*
* Allocate the hardware ring and PCI DMA bus address space for said.
*/
size_t hwlen = nelem * hwsize + stat_size;
void *hwring = dma_alloc_coherent(dev, hwlen, busaddrp, GFP_KERNEL);
if (!hwring)
return NULL;
/*
* If the caller wants a software ring, allocate it and return a
* pointer to it in *swringp.
*/
BUG_ON((swsize != 0) != (swringp != NULL));
if (swsize) {
void *swring = kcalloc(nelem, swsize, GFP_KERNEL);
if (!swring) {
dma_free_coherent(dev, hwlen, hwring, *busaddrp);
return NULL;
}
*(void **)swringp = swring;
}
return hwring;
}
/**
* sgl_len - calculates the size of an SGL of the given capacity
* @n: the number of SGL entries
*
* Calculates the number of flits (8-byte units) needed for a Direct
* Scatter/Gather List that can hold the given number of entries.
*/
static inline unsigned int sgl_len(unsigned int n)
{
/*
* A Direct Scatter Gather List uses 32-bit lengths and 64-bit PCI DMA
* addresses. The DSGL Work Request starts off with a 32-bit DSGL
* ULPTX header, then Length0, then Address0, then, for 1 <= i <= N,
* repeated sequences of { Length[i], Length[i+1], Address[i],
* Address[i+1] } (this ensures that all addresses are on 64-bit
* boundaries). If N is even, then Length[N+1] should be set to 0 and
* Address[N+1] is omitted.
*
* The following calculation incorporates all of the above. It's
* somewhat hard to follow but, briefly: the "+2" accounts for the
* first two flits which include the DSGL header, Length0 and
* Address0; the "(3*(n-1))/2" covers the main body of list entries (3
* flits for every pair of the remaining N) +1 if (n-1) is odd; and
* finally the "+((n-1)&1)" adds the one remaining flit needed if
* (n-1) is odd ...
*/
n--;
return (3 * n) / 2 + (n & 1) + 2;
}
/**
* flits_to_desc - returns the num of TX descriptors for the given flits
* @flits: the number of flits
*
* Returns the number of TX descriptors needed for the supplied number
* of flits.
*/
static inline unsigned int flits_to_desc(unsigned int flits)
{
BUG_ON(flits > SGE_MAX_WR_LEN / sizeof(__be64));
return DIV_ROUND_UP(flits, TXD_PER_EQ_UNIT);
}
/**
* is_eth_imm - can an Ethernet packet be sent as immediate data?
* @skb: the packet
*
* Returns whether an Ethernet packet is small enough to fit completely as
* immediate data.
*/
static inline int is_eth_imm(const struct sk_buff *skb)
{
/*
* The VF Driver uses the FW_ETH_TX_PKT_VM_WR firmware Work Request
* which does not accommodate immediate data. We could dike out all
* of the support code for immediate data but that would tie our hands
* too much if we ever want to enhace the firmware. It would also
* create more differences between the PF and VF Drivers.
*/
return false;
}
/**
* calc_tx_flits - calculate the number of flits for a packet TX WR
* @skb: the packet
*
* Returns the number of flits needed for a TX Work Request for the
* given Ethernet packet, including the needed WR and CPL headers.
*/
static inline unsigned int calc_tx_flits(const struct sk_buff *skb)
{
unsigned int flits;
/*
* If the skb is small enough, we can pump it out as a work request
* with only immediate data. In that case we just have to have the
* TX Packet header plus the skb data in the Work Request.
*/
if (is_eth_imm(skb))
return DIV_ROUND_UP(skb->len + sizeof(struct cpl_tx_pkt),
sizeof(__be64));
/*
* Otherwise, we're going to have to construct a Scatter gather list
* of the skb body and fragments. We also include the flits necessary
* for the TX Packet Work Request and CPL. We always have a firmware
* Write Header (incorporated as part of the cpl_tx_pkt_lso and
* cpl_tx_pkt structures), followed by either a TX Packet Write CPL
* message or, if we're doing a Large Send Offload, an LSO CPL message
* with an embedded TX Packet Write CPL message.
*/
flits = sgl_len(skb_shinfo(skb)->nr_frags + 1);
if (skb_shinfo(skb)->gso_size)
flits += (sizeof(struct fw_eth_tx_pkt_vm_wr) +
sizeof(struct cpl_tx_pkt_lso_core) +
sizeof(struct cpl_tx_pkt_core)) / sizeof(__be64);
else
flits += (sizeof(struct fw_eth_tx_pkt_vm_wr) +
sizeof(struct cpl_tx_pkt_core)) / sizeof(__be64);
return flits;
}
/**
* write_sgl - populate a Scatter/Gather List for a packet
* @skb: the packet
* @tq: the TX queue we are writing into
* @sgl: starting location for writing the SGL
* @end: points right after the end of the SGL
* @start: start offset into skb main-body data to include in the SGL
* @addr: the list of DMA bus addresses for the SGL elements
*
* Generates a Scatter/Gather List for the buffers that make up a packet.
* The caller must provide adequate space for the SGL that will be written.
* The SGL includes all of the packet's page fragments and the data in its
* main body except for the first @start bytes. @pos must be 16-byte
* aligned and within a TX descriptor with available space. @end points
* write after the end of the SGL but does not account for any potential
* wrap around, i.e., @end > @tq->stat.
*/
static void write_sgl(const struct sk_buff *skb, struct sge_txq *tq,
struct ulptx_sgl *sgl, u64 *end, unsigned int start,
const dma_addr_t *addr)
{
unsigned int i, len;
struct ulptx_sge_pair *to;
const struct skb_shared_info *si = skb_shinfo(skb);
unsigned int nfrags = si->nr_frags;
struct ulptx_sge_pair buf[MAX_SKB_FRAGS / 2 + 1];
len = skb_headlen(skb) - start;
if (likely(len)) {
sgl->len0 = htonl(len);
sgl->addr0 = cpu_to_be64(addr[0] + start);
nfrags++;
} else {
sgl->len0 = htonl(skb_frag_size(&si->frags[0]));
sgl->addr0 = cpu_to_be64(addr[1]);
}
sgl->cmd_nsge = htonl(ULPTX_CMD_V(ULP_TX_SC_DSGL) |
ULPTX_NSGE_V(nfrags));
if (likely(--nfrags == 0))
return;
/*
* Most of the complexity below deals with the possibility we hit the
* end of the queue in the middle of writing the SGL. For this case
* only we create the SGL in a temporary buffer and then copy it.
*/
to = (u8 *)end > (u8 *)tq->stat ? buf : sgl->sge;
for (i = (nfrags != si->nr_frags); nfrags >= 2; nfrags -= 2, to++) {
to->len[0] = cpu_to_be32(skb_frag_size(&si->frags[i]));
to->len[1] = cpu_to_be32(skb_frag_size(&si->frags[++i]));
to->addr[0] = cpu_to_be64(addr[i]);
to->addr[1] = cpu_to_be64(addr[++i]);
}
if (nfrags) {
to->len[0] = cpu_to_be32(skb_frag_size(&si->frags[i]));
to->len[1] = cpu_to_be32(0);
to->addr[0] = cpu_to_be64(addr[i + 1]);
}
if (unlikely((u8 *)end > (u8 *)tq->stat)) {
unsigned int part0 = (u8 *)tq->stat - (u8 *)sgl->sge, part1;
if (likely(part0))
memcpy(sgl->sge, buf, part0);
part1 = (u8 *)end - (u8 *)tq->stat;
memcpy(tq->desc, (u8 *)buf + part0, part1);
end = (void *)tq->desc + part1;
}
if ((uintptr_t)end & 8) /* 0-pad to multiple of 16 */
*end = 0;
}
/**
* ring_tx_db - check and potentially ring a TX queue's doorbell
* @adapter: the adapter
* @tq: the TX queue
* @n: number of new descriptors to give to HW
*
* Ring the doorbel for a TX queue.
*/
static inline void ring_tx_db(struct adapter *adapter, struct sge_txq *tq,
int n)
{
/* Make sure that all writes to the TX Descriptors are committed
* before we tell the hardware about them.
*/
wmb();
/* If we don't have access to the new User Doorbell (T5+), use the old
* doorbell mechanism; otherwise use the new BAR2 mechanism.
*/
if (unlikely(tq->bar2_addr == NULL)) {
u32 val = PIDX_V(n);
t4_write_reg(adapter, T4VF_SGE_BASE_ADDR + SGE_VF_KDOORBELL,
QID_V(tq->cntxt_id) | val);
} else {
u32 val = PIDX_T5_V(n);
/* T4 and later chips share the same PIDX field offset within
* the doorbell, but T5 and later shrank the field in order to
* gain a bit for Doorbell Priority. The field was absurdly
* large in the first place (14 bits) so we just use the T5
* and later limits and warn if a Queue ID is too large.
*/
WARN_ON(val & DBPRIO_F);
/* If we're only writing a single Egress Unit and the BAR2
* Queue ID is 0, we can use the Write Combining Doorbell
* Gather Buffer; otherwise we use the simple doorbell.
*/
if (n == 1 && tq->bar2_qid == 0) {
unsigned int index = (tq->pidx
? (tq->pidx - 1)
: (tq->size - 1));
__be64 *src = (__be64 *)&tq->desc[index];
__be64 __iomem *dst = (__be64 __iomem *)(tq->bar2_addr +
SGE_UDB_WCDOORBELL);
unsigned int count = EQ_UNIT / sizeof(__be64);
/* Copy the TX Descriptor in a tight loop in order to
* try to get it to the adapter in a single Write
* Combined transfer on the PCI-E Bus. If the Write
* Combine fails (say because of an interrupt, etc.)
* the hardware will simply take the last write as a
* simple doorbell write with a PIDX Increment of 1
* and will fetch the TX Descriptor from memory via
* DMA.
*/
while (count) {
/* the (__force u64) is because the compiler
* doesn't understand the endian swizzling
* going on
*/
writeq((__force u64)*src, dst);
src++;
dst++;
count--;
}
} else
writel(val | QID_V(tq->bar2_qid),
tq->bar2_addr + SGE_UDB_KDOORBELL);
/* This Write Memory Barrier will force the write to the User
* Doorbell area to be flushed. This is needed to prevent
* writes on different CPUs for the same queue from hitting
* the adapter out of order. This is required when some Work
* Requests take the Write Combine Gather Buffer path (user
* doorbell area offset [SGE_UDB_WCDOORBELL..+63]) and some
* take the traditional path where we simply increment the
* PIDX (User Doorbell area SGE_UDB_KDOORBELL) and have the
* hardware DMA read the actual Work Request.
*/
wmb();
}
}
/**
* inline_tx_skb - inline a packet's data into TX descriptors
* @skb: the packet
* @tq: the TX queue where the packet will be inlined
* @pos: starting position in the TX queue to inline the packet
*
* Inline a packet's contents directly into TX descriptors, starting at
* the given position within the TX DMA ring.
* Most of the complexity of this operation is dealing with wrap arounds
* in the middle of the packet we want to inline.
*/
static void inline_tx_skb(const struct sk_buff *skb, const struct sge_txq *tq,
void *pos)
{
u64 *p;
int left = (void *)tq->stat - pos;
if (likely(skb->len <= left)) {
if (likely(!skb->data_len))
skb_copy_from_linear_data(skb, pos, skb->len);
else
skb_copy_bits(skb, 0, pos, skb->len);
pos += skb->len;
} else {
skb_copy_bits(skb, 0, pos, left);
skb_copy_bits(skb, left, tq->desc, skb->len - left);
pos = (void *)tq->desc + (skb->len - left);
}
/* 0-pad to multiple of 16 */
p = PTR_ALIGN(pos, 8);
if ((uintptr_t)p & 8)
*p = 0;
}
/*
* Figure out what HW csum a packet wants and return the appropriate control
* bits.
*/
static u64 hwcsum(enum chip_type chip, const struct sk_buff *skb)
{
int csum_type;
const struct iphdr *iph = ip_hdr(skb);
if (iph->version == 4) {
if (iph->protocol == IPPROTO_TCP)
csum_type = TX_CSUM_TCPIP;
else if (iph->protocol == IPPROTO_UDP)
csum_type = TX_CSUM_UDPIP;
else {
nocsum:
/*
* unknown protocol, disable HW csum
* and hope a bad packet is detected
*/
return TXPKT_L4CSUM_DIS_F;
}
} else {
/*
* this doesn't work with extension headers
*/
const struct ipv6hdr *ip6h = (const struct ipv6hdr *)iph;
if (ip6h->nexthdr == IPPROTO_TCP)
csum_type = TX_CSUM_TCPIP6;
else if (ip6h->nexthdr == IPPROTO_UDP)
csum_type = TX_CSUM_UDPIP6;
else
goto nocsum;
}
if (likely(csum_type >= TX_CSUM_TCPIP)) {
u64 hdr_len = TXPKT_IPHDR_LEN_V(skb_network_header_len(skb));
int eth_hdr_len = skb_network_offset(skb) - ETH_HLEN;
if (chip <= CHELSIO_T5)
hdr_len |= TXPKT_ETHHDR_LEN_V(eth_hdr_len);
else
hdr_len |= T6_TXPKT_ETHHDR_LEN_V(eth_hdr_len);
return TXPKT_CSUM_TYPE_V(csum_type) | hdr_len;
} else {
int start = skb_transport_offset(skb);
return TXPKT_CSUM_TYPE_V(csum_type) |
TXPKT_CSUM_START_V(start) |
TXPKT_CSUM_LOC_V(start + skb->csum_offset);
}
}
/*
* Stop an Ethernet TX queue and record that state change.
*/
static void txq_stop(struct sge_eth_txq *txq)
{
netif_tx_stop_queue(txq->txq);
txq->q.stops++;
}
/*
* Advance our software state for a TX queue by adding n in use descriptors.
*/
static inline void txq_advance(struct sge_txq *tq, unsigned int n)
{
tq->in_use += n;
tq->pidx += n;
if (tq->pidx >= tq->size)
tq->pidx -= tq->size;
}
/**
* t4vf_eth_xmit - add a packet to an Ethernet TX queue
* @skb: the packet
* @dev: the egress net device
*
* Add a packet to an SGE Ethernet TX queue. Runs with softirqs disabled.
*/
netdev_tx_t t4vf_eth_xmit(struct sk_buff *skb, struct net_device *dev)
{
u32 wr_mid;
u64 cntrl, *end;
int qidx, credits, max_pkt_len;
unsigned int flits, ndesc;
struct adapter *adapter;
struct sge_eth_txq *txq;
const struct port_info *pi;
struct fw_eth_tx_pkt_vm_wr *wr;
struct cpl_tx_pkt_core *cpl;
const struct skb_shared_info *ssi;
dma_addr_t addr[MAX_SKB_FRAGS + 1];
const size_t fw_hdr_copy_len = sizeof(wr->firmware);
/*
* The chip minimum packet length is 10 octets but the firmware
* command that we are using requires that we copy the Ethernet header
* (including the VLAN tag) into the header so we reject anything
* smaller than that ...
*/
if (unlikely(skb->len < fw_hdr_copy_len))
goto out_free;
/* Discard the packet if the length is greater than mtu */
max_pkt_len = ETH_HLEN + dev->mtu;
if (skb_vlan_tagged(skb))
max_pkt_len += VLAN_HLEN;
if (!skb_shinfo(skb)->gso_size && (unlikely(skb->len > max_pkt_len)))
goto out_free;
/*
* Figure out which TX Queue we're going to use.
*/
pi = netdev_priv(dev);
adapter = pi->adapter;
qidx = skb_get_queue_mapping(skb);
BUG_ON(qidx >= pi->nqsets);
txq = &adapter->sge.ethtxq[pi->first_qset + qidx];
if (pi->vlan_id && !skb_vlan_tag_present(skb))
__vlan_hwaccel_put_tag(skb, cpu_to_be16(ETH_P_8021Q),
pi->vlan_id);
/*
* Take this opportunity to reclaim any TX Descriptors whose DMA
* transfers have completed.
*/
reclaim_completed_tx(adapter, &txq->q, true);
/*
* Calculate the number of flits and TX Descriptors we're going to
* need along with how many TX Descriptors will be left over after
* we inject our Work Request.
*/
flits = calc_tx_flits(skb);
ndesc = flits_to_desc(flits);
credits = txq_avail(&txq->q) - ndesc;
if (unlikely(credits < 0)) {
/*
* Not enough room for this packet's Work Request. Stop the
* TX Queue and return a "busy" condition. The queue will get
* started later on when the firmware informs us that space
* has opened up.
*/
txq_stop(txq);
dev_err(adapter->pdev_dev,
"%s: TX ring %u full while queue awake!\n",
dev->name, qidx);
return NETDEV_TX_BUSY;
}
if (!is_eth_imm(skb) &&
unlikely(map_skb(adapter->pdev_dev, skb, addr) < 0)) {
/*
* We need to map the skb into PCI DMA space (because it can't
* be in-lined directly into the Work Request) and the mapping
* operation failed. Record the error and drop the packet.
*/
txq->mapping_err++;
goto out_free;
}
wr_mid = FW_WR_LEN16_V(DIV_ROUND_UP(flits, 2));
if (unlikely(credits < ETHTXQ_STOP_THRES)) {
/*
* After we're done injecting the Work Request for this
* packet, we'll be below our "stop threshold" so stop the TX
* Queue now and schedule a request for an SGE Egress Queue
* Update message. The queue will get started later on when
* the firmware processes this Work Request and sends us an
* Egress Queue Status Update message indicating that space
* has opened up.
*/
txq_stop(txq);
wr_mid |= FW_WR_EQUEQ_F | FW_WR_EQUIQ_F;
}
/*
* Start filling in our Work Request. Note that we do _not_ handle
* the WR Header wrapping around the TX Descriptor Ring. If our
* maximum header size ever exceeds one TX Descriptor, we'll need to
* do something else here.
*/
BUG_ON(DIV_ROUND_UP(ETHTXQ_MAX_HDR, TXD_PER_EQ_UNIT) > 1);
wr = (void *)&txq->q.desc[txq->q.pidx];
wr->equiq_to_len16 = cpu_to_be32(wr_mid);
wr->r3[0] = cpu_to_be32(0);
wr->r3[1] = cpu_to_be32(0);
skb_copy_from_linear_data(skb, &wr->firmware, fw_hdr_copy_len);
end = (u64 *)wr + flits;
/*
* If this is a Large Send Offload packet we'll put in an LSO CPL
* message with an encapsulated TX Packet CPL message. Otherwise we
* just use a TX Packet CPL message.
*/
ssi = skb_shinfo(skb);
if (ssi->gso_size) {
struct cpl_tx_pkt_lso_core *lso = (void *)(wr + 1);
bool v6 = (ssi->gso_type & SKB_GSO_TCPV6) != 0;
int l3hdr_len = skb_network_header_len(skb);
int eth_xtra_len = skb_network_offset(skb) - ETH_HLEN;
wr->op_immdlen =
cpu_to_be32(FW_WR_OP_V(FW_ETH_TX_PKT_VM_WR) |
FW_WR_IMMDLEN_V(sizeof(*lso) +
sizeof(*cpl)));
/*
* Fill in the LSO CPL message.
*/
lso->lso_ctrl =
cpu_to_be32(LSO_OPCODE_V(CPL_TX_PKT_LSO) |
LSO_FIRST_SLICE_F |
LSO_LAST_SLICE_F |
LSO_IPV6_V(v6) |
LSO_ETHHDR_LEN_V(eth_xtra_len / 4) |
LSO_IPHDR_LEN_V(l3hdr_len / 4) |
LSO_TCPHDR_LEN_V(tcp_hdr(skb)->doff));
lso->ipid_ofst = cpu_to_be16(0);
lso->mss = cpu_to_be16(ssi->gso_size);
lso->seqno_offset = cpu_to_be32(0);
if (is_t4(adapter->params.chip))
lso->len = cpu_to_be32(skb->len);
else
lso->len = cpu_to_be32(LSO_T5_XFER_SIZE_V(skb->len));
/*
* Set up TX Packet CPL pointer, control word and perform
* accounting.
*/
cpl = (void *)(lso + 1);
if (CHELSIO_CHIP_VERSION(adapter->params.chip) <= CHELSIO_T5)
cntrl = TXPKT_ETHHDR_LEN_V(eth_xtra_len);
else
cntrl = T6_TXPKT_ETHHDR_LEN_V(eth_xtra_len);
cntrl |= TXPKT_CSUM_TYPE_V(v6 ?
TX_CSUM_TCPIP6 : TX_CSUM_TCPIP) |
TXPKT_IPHDR_LEN_V(l3hdr_len);
txq->tso++;
txq->tx_cso += ssi->gso_segs;
} else {
int len;
len = is_eth_imm(skb) ? skb->len + sizeof(*cpl) : sizeof(*cpl);
wr->op_immdlen =
cpu_to_be32(FW_WR_OP_V(FW_ETH_TX_PKT_VM_WR) |
FW_WR_IMMDLEN_V(len));
/*
* Set up TX Packet CPL pointer, control word and perform
* accounting.
*/
cpl = (void *)(wr + 1);
if (skb->ip_summed == CHECKSUM_PARTIAL) {
cntrl = hwcsum(adapter->params.chip, skb) |
TXPKT_IPCSUM_DIS_F;
txq->tx_cso++;
} else
cntrl = TXPKT_L4CSUM_DIS_F | TXPKT_IPCSUM_DIS_F;
}
/*
* If there's a VLAN tag present, add that to the list of things to
* do in this Work Request.
*/
if (skb_vlan_tag_present(skb)) {
txq->vlan_ins++;
cntrl |= TXPKT_VLAN_VLD_F | TXPKT_VLAN_V(skb_vlan_tag_get(skb));
}
/*
* Fill in the TX Packet CPL message header.
*/
cpl->ctrl0 = cpu_to_be32(TXPKT_OPCODE_V(CPL_TX_PKT_XT) |
TXPKT_INTF_V(pi->port_id) |
TXPKT_PF_V(0));
cpl->pack = cpu_to_be16(0);
cpl->len = cpu_to_be16(skb->len);
cpl->ctrl1 = cpu_to_be64(cntrl);
#ifdef T4_TRACE
T4_TRACE5(adapter->tb[txq->q.cntxt_id & 7],
"eth_xmit: ndesc %u, credits %u, pidx %u, len %u, frags %u",
ndesc, credits, txq->q.pidx, skb->len, ssi->nr_frags);
#endif
/*
* Fill in the body of the TX Packet CPL message with either in-lined
* data or a Scatter/Gather List.
*/
if (is_eth_imm(skb)) {
/*
* In-line the packet's data and free the skb since we don't
* need it any longer.
*/
inline_tx_skb(skb, &txq->q, cpl + 1);
dev_consume_skb_any(skb);
} else {
/*
* Write the skb's Scatter/Gather list into the TX Packet CPL
* message and retain a pointer to the skb so we can free it
* later when its DMA completes. (We store the skb pointer
* in the Software Descriptor corresponding to the last TX
* Descriptor used by the Work Request.)
*
* The retained skb will be freed when the corresponding TX
* Descriptors are reclaimed after their DMAs complete.
* However, this could take quite a while since, in general,
* the hardware is set up to be lazy about sending DMA
* completion notifications to us and we mostly perform TX
* reclaims in the transmit routine.
*
* This is good for performamce but means that we rely on new
* TX packets arriving to run the destructors of completed
* packets, which open up space in their sockets' send queues.
* Sometimes we do not get such new packets causing TX to
* stall. A single UDP transmitter is a good example of this
* situation. We have a clean up timer that periodically
* reclaims completed packets but it doesn't run often enough
* (nor do we want it to) to prevent lengthy stalls. A
* solution to this problem is to run the destructor early,
* after the packet is queued but before it's DMAd. A con is
* that we lie to socket memory accounting, but the amount of
* extra memory is reasonable (limited by the number of TX
* descriptors), the packets do actually get freed quickly by
* new packets almost always, and for protocols like TCP that
* wait for acks to really free up the data the extra memory
* is even less. On the positive side we run the destructors
* on the sending CPU rather than on a potentially different
* completing CPU, usually a good thing.
*
* Run the destructor before telling the DMA engine about the
* packet to make sure it doesn't complete and get freed
* prematurely.
*/
struct ulptx_sgl *sgl = (struct ulptx_sgl *)(cpl + 1);
struct sge_txq *tq = &txq->q;
int last_desc;
/*
* If the Work Request header was an exact multiple of our TX
* Descriptor length, then it's possible that the starting SGL
* pointer lines up exactly with the end of our TX Descriptor
* ring. If that's the case, wrap around to the beginning
* here ...
*/
if (unlikely((void *)sgl == (void *)tq->stat)) {
sgl = (void *)tq->desc;
end = ((void *)tq->desc + ((void *)end - (void *)tq->stat));
}
write_sgl(skb, tq, sgl, end, 0, addr);
skb_orphan(skb);
last_desc = tq->pidx + ndesc - 1;
if (last_desc >= tq->size)
last_desc -= tq->size;
tq->sdesc[last_desc].skb = skb;
tq->sdesc[last_desc].sgl = sgl;
}
/*
* Advance our internal TX Queue state, tell the hardware about
* the new TX descriptors and return success.
*/
txq_advance(&txq->q, ndesc);
netif_trans_update(dev);
ring_tx_db(adapter, &txq->q, ndesc);
return NETDEV_TX_OK;
out_free:
/*
* An error of some sort happened. Free the TX skb and tell the
* OS that we've "dealt" with the packet ...
*/
dev_kfree_skb_any(skb);
return NETDEV_TX_OK;
}
/**
* copy_frags - copy fragments from gather list into skb_shared_info
* @skb: destination skb
* @gl: source internal packet gather list
* @offset: packet start offset in first page
*
* Copy an internal packet gather list into a Linux skb_shared_info
* structure.
*/
static inline void copy_frags(struct sk_buff *skb,
const struct pkt_gl *gl,
unsigned int offset)
{
int i;
/* usually there's just one frag */
__skb_fill_page_desc(skb, 0, gl->frags[0].page,
gl->frags[0].offset + offset,
gl->frags[0].size - offset);
skb_shinfo(skb)->nr_frags = gl->nfrags;
for (i = 1; i < gl->nfrags; i++)
__skb_fill_page_desc(skb, i, gl->frags[i].page,
gl->frags[i].offset,
gl->frags[i].size);
/* get a reference to the last page, we don't own it */
get_page(gl->frags[gl->nfrags - 1].page);
}
/**
* t4vf_pktgl_to_skb - build an sk_buff from a packet gather list
* @gl: the gather list
* @skb_len: size of sk_buff main body if it carries fragments
* @pull_len: amount of data to move to the sk_buff's main body
*
* Builds an sk_buff from the given packet gather list. Returns the
* sk_buff or %NULL if sk_buff allocation failed.
*/
static struct sk_buff *t4vf_pktgl_to_skb(const struct pkt_gl *gl,
unsigned int skb_len,
unsigned int pull_len)
{
struct sk_buff *skb;
/*
* If the ingress packet is small enough, allocate an skb large enough
* for all of the data and copy it inline. Otherwise, allocate an skb
* with enough room to pull in the header and reference the rest of
* the data via the skb fragment list.
*
* Below we rely on RX_COPY_THRES being less than the smallest Rx
* buff! size, which is expected since buffers are at least
* PAGE_SIZEd. In this case packets up to RX_COPY_THRES have only one
* fragment.
*/
if (gl->tot_len <= RX_COPY_THRES) {
/* small packets have only one fragment */
skb = alloc_skb(gl->tot_len, GFP_ATOMIC);
if (unlikely(!skb))
goto out;
__skb_put(skb, gl->tot_len);
skb_copy_to_linear_data(skb, gl->va, gl->tot_len);
} else {
skb = alloc_skb(skb_len, GFP_ATOMIC);
if (unlikely(!skb))
goto out;
__skb_put(skb, pull_len);
skb_copy_to_linear_data(skb, gl->va, pull_len);
copy_frags(skb, gl, pull_len);
skb->len = gl->tot_len;
skb->data_len = skb->len - pull_len;
skb->truesize += skb->data_len;
}
out:
return skb;
}
/**
* t4vf_pktgl_free - free a packet gather list
* @gl: the gather list
*
* Releases the pages of a packet gather list. We do not own the last
* page on the list and do not free it.
*/
static void t4vf_pktgl_free(const struct pkt_gl *gl)
{
int frag;
frag = gl->nfrags - 1;
while (frag--)
put_page(gl->frags[frag].page);
}
/**
* do_gro - perform Generic Receive Offload ingress packet processing
* @rxq: ingress RX Ethernet Queue
* @gl: gather list for ingress packet
* @pkt: CPL header for last packet fragment
*
* Perform Generic Receive Offload (GRO) ingress packet processing.
* We use the standard Linux GRO interfaces for this.
*/
static void do_gro(struct sge_eth_rxq *rxq, const struct pkt_gl *gl,
const struct cpl_rx_pkt *pkt)
{
struct adapter *adapter = rxq->rspq.adapter;
struct sge *s = &adapter->sge;
struct port_info *pi;
int ret;
struct sk_buff *skb;
skb = napi_get_frags(&rxq->rspq.napi);
if (unlikely(!skb)) {
t4vf_pktgl_free(gl);
rxq->stats.rx_drops++;
return;
}
copy_frags(skb, gl, s->pktshift);
skb->len = gl->tot_len - s->pktshift;
skb->data_len = skb->len;
skb->truesize += skb->data_len;
skb->ip_summed = CHECKSUM_UNNECESSARY;
skb_record_rx_queue(skb, rxq->rspq.idx);
pi = netdev_priv(skb->dev);
if (pkt->vlan_ex && !pi->vlan_id) {
__vlan_hwaccel_put_tag(skb, cpu_to_be16(ETH_P_8021Q),
be16_to_cpu(pkt->vlan));
rxq->stats.vlan_ex++;
}
ret = napi_gro_frags(&rxq->rspq.napi);
if (ret == GRO_HELD)
rxq->stats.lro_pkts++;
else if (ret == GRO_MERGED || ret == GRO_MERGED_FREE)
rxq->stats.lro_merged++;
rxq->stats.pkts++;
rxq->stats.rx_cso++;
}
/**
* t4vf_ethrx_handler - process an ingress ethernet packet
* @rspq: the response queue that received the packet
* @rsp: the response queue descriptor holding the RX_PKT message
* @gl: the gather list of packet fragments
*
* Process an ingress ethernet packet and deliver it to the stack.
*/
int t4vf_ethrx_handler(struct sge_rspq *rspq, const __be64 *rsp,
const struct pkt_gl *gl)
{
struct sk_buff *skb;
const struct cpl_rx_pkt *pkt = (void *)rsp;
bool csum_ok = pkt->csum_calc && !pkt->err_vec &&
(rspq->netdev->features & NETIF_F_RXCSUM);
struct sge_eth_rxq *rxq = container_of(rspq, struct sge_eth_rxq, rspq);
struct adapter *adapter = rspq->adapter;
struct sge *s = &adapter->sge;
struct port_info *pi;
/*
* If this is a good TCP packet and we have Generic Receive Offload
* enabled, handle the packet in the GRO path.
*/
if ((pkt->l2info & cpu_to_be32(RXF_TCP_F)) &&
(rspq->netdev->features & NETIF_F_GRO) && csum_ok &&
!pkt->ip_frag) {
do_gro(rxq, gl, pkt);
return 0;
}
/*
* Convert the Packet Gather List into an skb.
*/
skb = t4vf_pktgl_to_skb(gl, RX_SKB_LEN, RX_PULL_LEN);
if (unlikely(!skb)) {
t4vf_pktgl_free(gl);
rxq->stats.rx_drops++;
return 0;
}
__skb_pull(skb, s->pktshift);
skb->protocol = eth_type_trans(skb, rspq->netdev);
skb_record_rx_queue(skb, rspq->idx);
pi = netdev_priv(skb->dev);
rxq->stats.pkts++;
if (csum_ok && !pkt->err_vec &&
(be32_to_cpu(pkt->l2info) & (RXF_UDP_F | RXF_TCP_F))) {
if (!pkt->ip_frag) {
skb->ip_summed = CHECKSUM_UNNECESSARY;
rxq->stats.rx_cso++;
} else if (pkt->l2info & htonl(RXF_IP_F)) {
__sum16 c = (__force __sum16)pkt->csum;
skb->csum = csum_unfold(c);
skb->ip_summed = CHECKSUM_COMPLETE;
rxq->stats.rx_cso++;
}
} else
skb_checksum_none_assert(skb);
if (pkt->vlan_ex && !pi->vlan_id) {
rxq->stats.vlan_ex++;
__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q),
be16_to_cpu(pkt->vlan));
}
netif_receive_skb(skb);
return 0;
}
/**
* is_new_response - check if a response is newly written
* @rc: the response control descriptor
* @rspq: the response queue
*
* Returns true if a response descriptor contains a yet unprocessed
* response.
*/
static inline bool is_new_response(const struct rsp_ctrl *rc,
const struct sge_rspq *rspq)
{
return ((rc->type_gen >> RSPD_GEN_S) & 0x1) == rspq->gen;
}
/**
* restore_rx_bufs - put back a packet's RX buffers
* @gl: the packet gather list
* @fl: the SGE Free List
* @frags: how many fragments in @si
*
* Called when we find out that the current packet, @si, can't be
* processed right away for some reason. This is a very rare event and
* there's no effort to make this suspension/resumption process
* particularly efficient.
*
* We implement the suspension by putting all of the RX buffers associated
* with the current packet back on the original Free List. The buffers
* have already been unmapped and are left unmapped, we mark them as
* unmapped in order to prevent further unmapping attempts. (Effectively
* this function undoes the series of @unmap_rx_buf calls which were done
* to create the current packet's gather list.) This leaves us ready to
* restart processing of the packet the next time we start processing the
* RX Queue ...
*/
static void restore_rx_bufs(const struct pkt_gl *gl, struct sge_fl *fl,
int frags)
{
struct rx_sw_desc *sdesc;
while (frags--) {
if (fl->cidx == 0)
fl->cidx = fl->size - 1;
else
fl->cidx--;
sdesc = &fl->sdesc[fl->cidx];
sdesc->page = gl->frags[frags].page;
sdesc->dma_addr |= RX_UNMAPPED_BUF;
fl->avail++;
}
}
/**
* rspq_next - advance to the next entry in a response queue
* @rspq: the queue
*
* Updates the state of a response queue to advance it to the next entry.
*/
static inline void rspq_next(struct sge_rspq *rspq)
{
rspq->cur_desc = (void *)rspq->cur_desc + rspq->iqe_len;
if (unlikely(++rspq->cidx == rspq->size)) {
rspq->cidx = 0;
rspq->gen ^= 1;
rspq->cur_desc = rspq->desc;
}
}
/**
* process_responses - process responses from an SGE response queue
* @rspq: the ingress response queue to process
* @budget: how many responses can be processed in this round
*
* Process responses from a Scatter Gather Engine response queue up to
* the supplied budget. Responses include received packets as well as
* control messages from firmware or hardware.
*
* Additionally choose the interrupt holdoff time for the next interrupt
* on this queue. If the system is under memory shortage use a fairly
* long delay to help recovery.
*/
static int process_responses(struct sge_rspq *rspq, int budget)
{
struct sge_eth_rxq *rxq = container_of(rspq, struct sge_eth_rxq, rspq);
struct adapter *adapter = rspq->adapter;
struct sge *s = &adapter->sge;
int budget_left = budget;
while (likely(budget_left)) {
int ret, rsp_type;
const struct rsp_ctrl *rc;
rc = (void *)rspq->cur_desc + (rspq->iqe_len - sizeof(*rc));
if (!is_new_response(rc, rspq))
break;
/*
* Figure out what kind of response we've received from the
* SGE.
*/
dma_rmb();
rsp_type = RSPD_TYPE_G(rc->type_gen);
if (likely(rsp_type == RSPD_TYPE_FLBUF_X)) {
struct page_frag *fp;
struct pkt_gl gl;
const struct rx_sw_desc *sdesc;
u32 bufsz, frag;
u32 len = be32_to_cpu(rc->pldbuflen_qid);
/*
* If we get a "new buffer" message from the SGE we
* need to move on to the next Free List buffer.
*/
if (len & RSPD_NEWBUF_F) {
/*
* We get one "new buffer" message when we
* first start up a queue so we need to ignore
* it when our offset into the buffer is 0.
*/
if (likely(rspq->offset > 0)) {
free_rx_bufs(rspq->adapter, &rxq->fl,
1);
rspq->offset = 0;
}
len = RSPD_LEN_G(len);
}
gl.tot_len = len;
/*
* Gather packet fragments.
*/
for (frag = 0, fp = gl.frags; /**/; frag++, fp++) {
BUG_ON(frag >= MAX_SKB_FRAGS);
BUG_ON(rxq->fl.avail == 0);
sdesc = &rxq->fl.sdesc[rxq->fl.cidx];
bufsz = get_buf_size(adapter, sdesc);
fp->page = sdesc->page;
fp->offset = rspq->offset;
fp->size = min(bufsz, len);
len -= fp->size;
if (!len)
break;
unmap_rx_buf(rspq->adapter, &rxq->fl);
}
gl.nfrags = frag+1;
/*
* Last buffer remains mapped so explicitly make it
* coherent for CPU access and start preloading first
* cache line ...
*/
dma_sync_single_for_cpu(rspq->adapter->pdev_dev,
get_buf_addr(sdesc),
fp->size, DMA_FROM_DEVICE);
gl.va = (page_address(gl.frags[0].page) +
gl.frags[0].offset);
prefetch(gl.va);
/*
* Hand the new ingress packet to the handler for
* this Response Queue.
*/
ret = rspq->handler(rspq, rspq->cur_desc, &gl);
if (likely(ret == 0))
rspq->offset += ALIGN(fp->size, s->fl_align);
else
restore_rx_bufs(&gl, &rxq->fl, frag);
} else if (likely(rsp_type == RSPD_TYPE_CPL_X)) {
ret = rspq->handler(rspq, rspq->cur_desc, NULL);
} else {
WARN_ON(rsp_type > RSPD_TYPE_CPL_X);
ret = 0;
}
if (unlikely(ret)) {
/*
* Couldn't process descriptor, back off for recovery.
* We use the SGE's last timer which has the longest
* interrupt coalescing value ...
*/
const int NOMEM_TIMER_IDX = SGE_NTIMERS-1;
rspq->next_intr_params =
QINTR_TIMER_IDX_V(NOMEM_TIMER_IDX);
break;
}
rspq_next(rspq);
budget_left--;
}
/*
* If this is a Response Queue with an associated Free List and
* at least two Egress Queue units available in the Free List
* for new buffer pointers, refill the Free List.
*/
if (rspq->offset >= 0 &&
fl_cap(&rxq->fl) - rxq->fl.avail >= 2*FL_PER_EQ_UNIT)
__refill_fl(rspq->adapter, &rxq->fl);
return budget - budget_left;
}
/**
* napi_rx_handler - the NAPI handler for RX processing
* @napi: the napi instance
* @budget: how many packets we can process in this round
*
* Handler for new data events when using NAPI. This does not need any
* locking or protection from interrupts as data interrupts are off at
* this point and other adapter interrupts do not interfere (the latter
* in not a concern at all with MSI-X as non-data interrupts then have
* a separate handler).
*/
static int napi_rx_handler(struct napi_struct *napi, int budget)
{
unsigned int intr_params;
struct sge_rspq *rspq = container_of(napi, struct sge_rspq, napi);
int work_done = process_responses(rspq, budget);
u32 val;
if (likely(work_done < budget)) {
napi_complete_done(napi, work_done);
intr_params = rspq->next_intr_params;
rspq->next_intr_params = rspq->intr_params;
} else
intr_params = QINTR_TIMER_IDX_V(SGE_TIMER_UPD_CIDX);
if (unlikely(work_done == 0))
rspq->unhandled_irqs++;
val = CIDXINC_V(work_done) | SEINTARM_V(intr_params);
/* If we don't have access to the new User GTS (T5+), use the old
* doorbell mechanism; otherwise use the new BAR2 mechanism.
*/
if (unlikely(!rspq->bar2_addr)) {
t4_write_reg(rspq->adapter,
T4VF_SGE_BASE_ADDR + SGE_VF_GTS,
val | INGRESSQID_V((u32)rspq->cntxt_id));
} else {
writel(val | INGRESSQID_V(rspq->bar2_qid),
rspq->bar2_addr + SGE_UDB_GTS);
wmb();
}
return work_done;
}
/*
* The MSI-X interrupt handler for an SGE response queue for the NAPI case
* (i.e., response queue serviced by NAPI polling).
*/
irqreturn_t t4vf_sge_intr_msix(int irq, void *cookie)
{
struct sge_rspq *rspq = cookie;
napi_schedule(&rspq->napi);
return IRQ_HANDLED;
}
/*
* Process the indirect interrupt entries in the interrupt queue and kick off
* NAPI for each queue that has generated an entry.
*/
static unsigned int process_intrq(struct adapter *adapter)
{
struct sge *s = &adapter->sge;
struct sge_rspq *intrq = &s->intrq;
unsigned int work_done;
u32 val;
spin_lock(&adapter->sge.intrq_lock);
for (work_done = 0; ; work_done++) {
const struct rsp_ctrl *rc;
unsigned int qid, iq_idx;
struct sge_rspq *rspq;
/*
* Grab the next response from the interrupt queue and bail
* out if it's not a new response.
*/
rc = (void *)intrq->cur_desc + (intrq->iqe_len - sizeof(*rc));
if (!is_new_response(rc, intrq))
break;
/*
* If the response isn't a forwarded interrupt message issue a
* error and go on to the next response message. This should
* never happen ...
*/
dma_rmb();
if (unlikely(RSPD_TYPE_G(rc->type_gen) != RSPD_TYPE_INTR_X)) {
dev_err(adapter->pdev_dev,
"Unexpected INTRQ response type %d\n",
RSPD_TYPE_G(rc->type_gen));
continue;
}
/*
* Extract the Queue ID from the interrupt message and perform
* sanity checking to make sure it really refers to one of our
* Ingress Queues which is active and matches the queue's ID.
* None of these error conditions should ever happen so we may
* want to either make them fatal and/or conditionalized under
* DEBUG.
*/
qid = RSPD_QID_G(be32_to_cpu(rc->pldbuflen_qid));
iq_idx = IQ_IDX(s, qid);
if (unlikely(iq_idx >= MAX_INGQ)) {
dev_err(adapter->pdev_dev,
"Ingress QID %d out of range\n", qid);
continue;
}
rspq = s->ingr_map[iq_idx];
if (unlikely(rspq == NULL)) {
dev_err(adapter->pdev_dev,
"Ingress QID %d RSPQ=NULL\n", qid);
continue;
}
if (unlikely(rspq->abs_id != qid)) {
dev_err(adapter->pdev_dev,
"Ingress QID %d refers to RSPQ %d\n",
qid, rspq->abs_id);
continue;
}
/*
* Schedule NAPI processing on the indicated Response Queue
* and move on to the next entry in the Forwarded Interrupt
* Queue.
*/
napi_schedule(&rspq->napi);
rspq_next(intrq);
}
val = CIDXINC_V(work_done) | SEINTARM_V(intrq->intr_params);
/* If we don't have access to the new User GTS (T5+), use the old
* doorbell mechanism; otherwise use the new BAR2 mechanism.
*/
if (unlikely(!intrq->bar2_addr)) {
t4_write_reg(adapter, T4VF_SGE_BASE_ADDR + SGE_VF_GTS,
val | INGRESSQID_V(intrq->cntxt_id));
} else {
writel(val | INGRESSQID_V(intrq->bar2_qid),
intrq->bar2_addr + SGE_UDB_GTS);
wmb();
}
spin_unlock(&adapter->sge.intrq_lock);
return work_done;
}
/*
* The MSI interrupt handler handles data events from SGE response queues as
* well as error and other async events as they all use the same MSI vector.
*/
static irqreturn_t t4vf_intr_msi(int irq, void *cookie)
{
struct adapter *adapter = cookie;
process_intrq(adapter);
return IRQ_HANDLED;
}
/**
* t4vf_intr_handler - select the top-level interrupt handler
* @adapter: the adapter
*
* Selects the top-level interrupt handler based on the type of interrupts
* (MSI-X or MSI).
*/
irq_handler_t t4vf_intr_handler(struct adapter *adapter)
{
BUG_ON((adapter->flags &
(CXGB4VF_USING_MSIX | CXGB4VF_USING_MSI)) == 0);
if (adapter->flags & CXGB4VF_USING_MSIX)
return t4vf_sge_intr_msix;
else
return t4vf_intr_msi;
}
/**
* sge_rx_timer_cb - perform periodic maintenance of SGE RX queues
* @t: Rx timer
*
* Runs periodically from a timer to perform maintenance of SGE RX queues.
*
* a) Replenishes RX queues that have run out due to memory shortage.
* Normally new RX buffers are added when existing ones are consumed but
* when out of memory a queue can become empty. We schedule NAPI to do
* the actual refill.
*/
static void sge_rx_timer_cb(struct timer_list *t)
{
struct adapter *adapter = from_timer(adapter, t, sge.rx_timer);
struct sge *s = &adapter->sge;
unsigned int i;
/*
* Scan the "Starving Free Lists" flag array looking for any Free
* Lists in need of more free buffers. If we find one and it's not
* being actively polled, then bump its "starving" counter and attempt
* to refill it. If we're successful in adding enough buffers to push
* the Free List over the starving threshold, then we can clear its
* "starving" status.
*/
for (i = 0; i < ARRAY_SIZE(s->starving_fl); i++) {
unsigned long m;
for (m = s->starving_fl[i]; m; m &= m - 1) {
unsigned int id = __ffs(m) + i * BITS_PER_LONG;
struct sge_fl *fl = s->egr_map[id];
clear_bit(id, s->starving_fl);
smp_mb__after_atomic();
/*
* Since we are accessing fl without a lock there's a
* small probability of a false positive where we
* schedule napi but the FL is no longer starving.
* No biggie.
*/
if (fl_starving(adapter, fl)) {
struct sge_eth_rxq *rxq;
rxq = container_of(fl, struct sge_eth_rxq, fl);
if (napi_reschedule(&rxq->rspq.napi))
fl->starving++;
else
set_bit(id, s->starving_fl);
}
}
}
/*
* Reschedule the next scan for starving Free Lists ...
*/
mod_timer(&s->rx_timer, jiffies + RX_QCHECK_PERIOD);
}
/**
* sge_tx_timer_cb - perform periodic maintenance of SGE Tx queues
* @t: Tx timer
*
* Runs periodically from a timer to perform maintenance of SGE TX queues.
*
* b) Reclaims completed Tx packets for the Ethernet queues. Normally
* packets are cleaned up by new Tx packets, this timer cleans up packets
* when no new packets are being submitted. This is essential for pktgen,
* at least.
*/
static void sge_tx_timer_cb(struct timer_list *t)
{
struct adapter *adapter = from_timer(adapter, t, sge.tx_timer);
struct sge *s = &adapter->sge;
unsigned int i, budget;
budget = MAX_TIMER_TX_RECLAIM;
i = s->ethtxq_rover;
do {
struct sge_eth_txq *txq = &s->ethtxq[i];
if (reclaimable(&txq->q) && __netif_tx_trylock(txq->txq)) {
int avail = reclaimable(&txq->q);
if (avail > budget)
avail = budget;
free_tx_desc(adapter, &txq->q, avail, true);
txq->q.in_use -= avail;
__netif_tx_unlock(txq->txq);
budget -= avail;
if (!budget)
break;
}
i++;
if (i >= s->ethqsets)
i = 0;
} while (i != s->ethtxq_rover);
s->ethtxq_rover = i;
/*
* If we found too many reclaimable packets schedule a timer in the
* near future to continue where we left off. Otherwise the next timer
* will be at its normal interval.
*/
mod_timer(&s->tx_timer, jiffies + (budget ? TX_QCHECK_PERIOD : 2));
}
/**
* bar2_address - return the BAR2 address for an SGE Queue's Registers
* @adapter: the adapter
* @qid: the SGE Queue ID
* @qtype: the SGE Queue Type (Egress or Ingress)
* @pbar2_qid: BAR2 Queue ID or 0 for Queue ID inferred SGE Queues
*
* Returns the BAR2 address for the SGE Queue Registers associated with
* @qid. If BAR2 SGE Registers aren't available, returns NULL. Also
* returns the BAR2 Queue ID to be used with writes to the BAR2 SGE
* Queue Registers. If the BAR2 Queue ID is 0, then "Inferred Queue ID"
* Registers are supported (e.g. the Write Combining Doorbell Buffer).
*/
static void __iomem *bar2_address(struct adapter *adapter,
unsigned int qid,
enum t4_bar2_qtype qtype,
unsigned int *pbar2_qid)
{
u64 bar2_qoffset;
int ret;
ret = t4vf_bar2_sge_qregs(adapter, qid, qtype,
&bar2_qoffset, pbar2_qid);
if (ret)
return NULL;
return adapter->bar2 + bar2_qoffset;
}
/**
* t4vf_sge_alloc_rxq - allocate an SGE RX Queue
* @adapter: the adapter
* @rspq: pointer to to the new rxq's Response Queue to be filled in
* @iqasynch: if 0, a normal rspq; if 1, an asynchronous event queue
* @dev: the network device associated with the new rspq
* @intr_dest: MSI-X vector index (overriden in MSI mode)
* @fl: pointer to the new rxq's Free List to be filled in
* @hnd: the interrupt handler to invoke for the rspq
*/
int t4vf_sge_alloc_rxq(struct adapter *adapter, struct sge_rspq *rspq,
bool iqasynch, struct net_device *dev,
int intr_dest,
struct sge_fl *fl, rspq_handler_t hnd)
{
struct sge *s = &adapter->sge;
struct port_info *pi = netdev_priv(dev);
struct fw_iq_cmd cmd, rpl;
int ret, iqandst, flsz = 0;
int relaxed = !(adapter->flags & CXGB4VF_ROOT_NO_RELAXED_ORDERING);
/*
* If we're using MSI interrupts and we're not initializing the
* Forwarded Interrupt Queue itself, then set up this queue for
* indirect interrupts to the Forwarded Interrupt Queue. Obviously
* the Forwarded Interrupt Queue must be set up before any other
* ingress queue ...
*/
if ((adapter->flags & CXGB4VF_USING_MSI) &&
rspq != &adapter->sge.intrq) {
iqandst = SGE_INTRDST_IQ;
intr_dest = adapter->sge.intrq.abs_id;
} else
iqandst = SGE_INTRDST_PCI;
/*
* Allocate the hardware ring for the Response Queue. The size needs
* to be a multiple of 16 which includes the mandatory status entry
* (regardless of whether the Status Page capabilities are enabled or
* not).
*/
rspq->size = roundup(rspq->size, 16);
rspq->desc = alloc_ring(adapter->pdev_dev, rspq->size, rspq->iqe_len,
0, &rspq->phys_addr, NULL, 0);
if (!rspq->desc)
return -ENOMEM;
/*
* Fill in the Ingress Queue Command. Note: Ideally this code would
* be in t4vf_hw.c but there are so many parameters and dependencies
* on our Linux SGE state that we would end up having to pass tons of
* parameters. We'll have to think about how this might be migrated
* into OS-independent common code ...
*/
memset(&cmd, 0, sizeof(cmd));
cmd.op_to_vfn = cpu_to_be32(FW_CMD_OP_V(FW_IQ_CMD) |
FW_CMD_REQUEST_F |
FW_CMD_WRITE_F |
FW_CMD_EXEC_F);
cmd.alloc_to_len16 = cpu_to_be32(FW_IQ_CMD_ALLOC_F |
FW_IQ_CMD_IQSTART_F |
FW_LEN16(cmd));
cmd.type_to_iqandstindex =
cpu_to_be32(FW_IQ_CMD_TYPE_V(FW_IQ_TYPE_FL_INT_CAP) |
FW_IQ_CMD_IQASYNCH_V(iqasynch) |
FW_IQ_CMD_VIID_V(pi->viid) |
FW_IQ_CMD_IQANDST_V(iqandst) |
FW_IQ_CMD_IQANUS_V(1) |
FW_IQ_CMD_IQANUD_V(SGE_UPDATEDEL_INTR) |
FW_IQ_CMD_IQANDSTINDEX_V(intr_dest));
cmd.iqdroprss_to_iqesize =
cpu_to_be16(FW_IQ_CMD_IQPCIECH_V(pi->port_id) |
FW_IQ_CMD_IQGTSMODE_F |
FW_IQ_CMD_IQINTCNTTHRESH_V(rspq->pktcnt_idx) |
FW_IQ_CMD_IQESIZE_V(ilog2(rspq->iqe_len) - 4));
cmd.iqsize = cpu_to_be16(rspq->size);
cmd.iqaddr = cpu_to_be64(rspq->phys_addr);
if (fl) {
unsigned int chip_ver =
CHELSIO_CHIP_VERSION(adapter->params.chip);
/*
* Allocate the ring for the hardware free list (with space
* for its status page) along with the associated software
* descriptor ring. The free list size needs to be a multiple
* of the Egress Queue Unit and at least 2 Egress Units larger
* than the SGE's Egress Congrestion Threshold
* (fl_starve_thres - 1).
*/
if (fl->size < s->fl_starve_thres - 1 + 2 * FL_PER_EQ_UNIT)
fl->size = s->fl_starve_thres - 1 + 2 * FL_PER_EQ_UNIT;
fl->size = roundup(fl->size, FL_PER_EQ_UNIT);
fl->desc = alloc_ring(adapter->pdev_dev, fl->size,
sizeof(__be64), sizeof(struct rx_sw_desc),
&fl->addr, &fl->sdesc, s->stat_len);
if (!fl->desc) {
ret = -ENOMEM;
goto err;
}
/*
* Calculate the size of the hardware free list ring plus
* Status Page (which the SGE will place after the end of the
* free list ring) in Egress Queue Units.
*/
flsz = (fl->size / FL_PER_EQ_UNIT +
s->stat_len / EQ_UNIT);
/*
* Fill in all the relevant firmware Ingress Queue Command
* fields for the free list.
*/
cmd.iqns_to_fl0congen =
cpu_to_be32(
FW_IQ_CMD_FL0HOSTFCMODE_V(SGE_HOSTFCMODE_NONE) |
FW_IQ_CMD_FL0PACKEN_F |
FW_IQ_CMD_FL0FETCHRO_V(relaxed) |
FW_IQ_CMD_FL0DATARO_V(relaxed) |
FW_IQ_CMD_FL0PADEN_F);
/* In T6, for egress queue type FL there is internal overhead
* of 16B for header going into FLM module. Hence the maximum
* allowed burst size is 448 bytes. For T4/T5, the hardware
* doesn't coalesce fetch requests if more than 64 bytes of
* Free List pointers are provided, so we use a 128-byte Fetch
* Burst Minimum there (T6 implements coalescing so we can use
* the smaller 64-byte value there).
*/
cmd.fl0dcaen_to_fl0cidxfthresh =
cpu_to_be16(
FW_IQ_CMD_FL0FBMIN_V(chip_ver <= CHELSIO_T5
? FETCHBURSTMIN_128B_X
: FETCHBURSTMIN_64B_T6_X) |
FW_IQ_CMD_FL0FBMAX_V((chip_ver <= CHELSIO_T5) ?
FETCHBURSTMAX_512B_X :
FETCHBURSTMAX_256B_X));
cmd.fl0size = cpu_to_be16(flsz);
cmd.fl0addr = cpu_to_be64(fl->addr);
}
/*
* Issue the firmware Ingress Queue Command and extract the results if
* it completes successfully.
*/
ret = t4vf_wr_mbox(adapter, &cmd, sizeof(cmd), &rpl);
if (ret)
goto err;
netif_napi_add(dev, &rspq->napi, napi_rx_handler);
rspq->cur_desc = rspq->desc;
rspq->cidx = 0;
rspq->gen = 1;
rspq->next_intr_params = rspq->intr_params;
rspq->cntxt_id = be16_to_cpu(rpl.iqid);
rspq->bar2_addr = bar2_address(adapter,
rspq->cntxt_id,
T4_BAR2_QTYPE_INGRESS,
&rspq->bar2_qid);
rspq->abs_id = be16_to_cpu(rpl.physiqid);
rspq->size--; /* subtract status entry */
rspq->adapter = adapter;
rspq->netdev = dev;
rspq->handler = hnd;
/* set offset to -1 to distinguish ingress queues without FL */
rspq->offset = fl ? 0 : -1;
if (fl) {
fl->cntxt_id = be16_to_cpu(rpl.fl0id);
fl->avail = 0;
fl->pend_cred = 0;
fl->pidx = 0;
fl->cidx = 0;
fl->alloc_failed = 0;
fl->large_alloc_failed = 0;
fl->starving = 0;
/* Note, we must initialize the BAR2 Free List User Doorbell
* information before refilling the Free List!
*/
fl->bar2_addr = bar2_address(adapter,
fl->cntxt_id,
T4_BAR2_QTYPE_EGRESS,
&fl->bar2_qid);
refill_fl(adapter, fl, fl_cap(fl), GFP_KERNEL);
}
return 0;
err:
/*
* An error occurred. Clean up our partial allocation state and
* return the error.
*/
if (rspq->desc) {
dma_free_coherent(adapter->pdev_dev, rspq->size * rspq->iqe_len,
rspq->desc, rspq->phys_addr);
rspq->desc = NULL;
}
if (fl && fl->desc) {
kfree(fl->sdesc);
fl->sdesc = NULL;
dma_free_coherent(adapter->pdev_dev, flsz * EQ_UNIT,
fl->desc, fl->addr);
fl->desc = NULL;
}
return ret;
}
/**
* t4vf_sge_alloc_eth_txq - allocate an SGE Ethernet TX Queue
* @adapter: the adapter
* @txq: pointer to the new txq to be filled in
* @dev: the network device
* @devq: the network TX queue associated with the new txq
* @iqid: the relative ingress queue ID to which events relating to
* the new txq should be directed
*/
int t4vf_sge_alloc_eth_txq(struct adapter *adapter, struct sge_eth_txq *txq,
struct net_device *dev, struct netdev_queue *devq,
unsigned int iqid)
{
unsigned int chip_ver = CHELSIO_CHIP_VERSION(adapter->params.chip);
struct port_info *pi = netdev_priv(dev);
struct fw_eq_eth_cmd cmd, rpl;
struct sge *s = &adapter->sge;
int ret, nentries;
/*
* Calculate the size of the hardware TX Queue (including the Status
* Page on the end of the TX Queue) in units of TX Descriptors.
*/
nentries = txq->q.size + s->stat_len / sizeof(struct tx_desc);
/*
* Allocate the hardware ring for the TX ring (with space for its
* status page) along with the associated software descriptor ring.
*/
txq->q.desc = alloc_ring(adapter->pdev_dev, txq->q.size,
sizeof(struct tx_desc),
sizeof(struct tx_sw_desc),
&txq->q.phys_addr, &txq->q.sdesc, s->stat_len);
if (!txq->q.desc)
return -ENOMEM;
/*
* Fill in the Egress Queue Command. Note: As with the direct use of
* the firmware Ingress Queue COmmand above in our RXQ allocation
* routine, ideally, this code would be in t4vf_hw.c. Again, we'll
* have to see if there's some reasonable way to parameterize it
* into the common code ...
*/
memset(&cmd, 0, sizeof(cmd));
cmd.op_to_vfn = cpu_to_be32(FW_CMD_OP_V(FW_EQ_ETH_CMD) |
FW_CMD_REQUEST_F |
FW_CMD_WRITE_F |
FW_CMD_EXEC_F);
cmd.alloc_to_len16 = cpu_to_be32(FW_EQ_ETH_CMD_ALLOC_F |
FW_EQ_ETH_CMD_EQSTART_F |
FW_LEN16(cmd));
cmd.autoequiqe_to_viid = cpu_to_be32(FW_EQ_ETH_CMD_AUTOEQUEQE_F |
FW_EQ_ETH_CMD_VIID_V(pi->viid));
cmd.fetchszm_to_iqid =
cpu_to_be32(FW_EQ_ETH_CMD_HOSTFCMODE_V(SGE_HOSTFCMODE_STPG) |
FW_EQ_ETH_CMD_PCIECHN_V(pi->port_id) |
FW_EQ_ETH_CMD_IQID_V(iqid));
cmd.dcaen_to_eqsize =
cpu_to_be32(FW_EQ_ETH_CMD_FBMIN_V(chip_ver <= CHELSIO_T5
? FETCHBURSTMIN_64B_X
: FETCHBURSTMIN_64B_T6_X) |
FW_EQ_ETH_CMD_FBMAX_V(FETCHBURSTMAX_512B_X) |
FW_EQ_ETH_CMD_CIDXFTHRESH_V(
CIDXFLUSHTHRESH_32_X) |
FW_EQ_ETH_CMD_EQSIZE_V(nentries));
cmd.eqaddr = cpu_to_be64(txq->q.phys_addr);
/*
* Issue the firmware Egress Queue Command and extract the results if
* it completes successfully.
*/
ret = t4vf_wr_mbox(adapter, &cmd, sizeof(cmd), &rpl);
if (ret) {
/*
* The girmware Ingress Queue Command failed for some reason.
* Free up our partial allocation state and return the error.
*/
kfree(txq->q.sdesc);
txq->q.sdesc = NULL;
dma_free_coherent(adapter->pdev_dev,
nentries * sizeof(struct tx_desc),
txq->q.desc, txq->q.phys_addr);
txq->q.desc = NULL;
return ret;
}
txq->q.in_use = 0;
txq->q.cidx = 0;
txq->q.pidx = 0;
txq->q.stat = (void *)&txq->q.desc[txq->q.size];
txq->q.cntxt_id = FW_EQ_ETH_CMD_EQID_G(be32_to_cpu(rpl.eqid_pkd));
txq->q.bar2_addr = bar2_address(adapter,
txq->q.cntxt_id,
T4_BAR2_QTYPE_EGRESS,
&txq->q.bar2_qid);
txq->q.abs_id =
FW_EQ_ETH_CMD_PHYSEQID_G(be32_to_cpu(rpl.physeqid_pkd));
txq->txq = devq;
txq->tso = 0;
txq->tx_cso = 0;
txq->vlan_ins = 0;
txq->q.stops = 0;
txq->q.restarts = 0;
txq->mapping_err = 0;
return 0;
}
/*
* Free the DMA map resources associated with a TX queue.
*/
static void free_txq(struct adapter *adapter, struct sge_txq *tq)
{
struct sge *s = &adapter->sge;
dma_free_coherent(adapter->pdev_dev,
tq->size * sizeof(*tq->desc) + s->stat_len,
tq->desc, tq->phys_addr);
tq->cntxt_id = 0;
tq->sdesc = NULL;
tq->desc = NULL;
}
/*
* Free the resources associated with a response queue (possibly including a
* free list).
*/
static void free_rspq_fl(struct adapter *adapter, struct sge_rspq *rspq,
struct sge_fl *fl)
{
struct sge *s = &adapter->sge;
unsigned int flid = fl ? fl->cntxt_id : 0xffff;
t4vf_iq_free(adapter, FW_IQ_TYPE_FL_INT_CAP,
rspq->cntxt_id, flid, 0xffff);
dma_free_coherent(adapter->pdev_dev, (rspq->size + 1) * rspq->iqe_len,
rspq->desc, rspq->phys_addr);
netif_napi_del(&rspq->napi);
rspq->netdev = NULL;
rspq->cntxt_id = 0;
rspq->abs_id = 0;
rspq->desc = NULL;
if (fl) {
free_rx_bufs(adapter, fl, fl->avail);
dma_free_coherent(adapter->pdev_dev,
fl->size * sizeof(*fl->desc) + s->stat_len,
fl->desc, fl->addr);
kfree(fl->sdesc);
fl->sdesc = NULL;
fl->cntxt_id = 0;
fl->desc = NULL;
}
}
/**
* t4vf_free_sge_resources - free SGE resources
* @adapter: the adapter
*
* Frees resources used by the SGE queue sets.
*/
void t4vf_free_sge_resources(struct adapter *adapter)
{
struct sge *s = &adapter->sge;
struct sge_eth_rxq *rxq = s->ethrxq;
struct sge_eth_txq *txq = s->ethtxq;
struct sge_rspq *evtq = &s->fw_evtq;
struct sge_rspq *intrq = &s->intrq;
int qs;
for (qs = 0; qs < adapter->sge.ethqsets; qs++, rxq++, txq++) {
if (rxq->rspq.desc)
free_rspq_fl(adapter, &rxq->rspq, &rxq->fl);
if (txq->q.desc) {
t4vf_eth_eq_free(adapter, txq->q.cntxt_id);
free_tx_desc(adapter, &txq->q, txq->q.in_use, true);
kfree(txq->q.sdesc);
free_txq(adapter, &txq->q);
}
}
if (evtq->desc)
free_rspq_fl(adapter, evtq, NULL);
if (intrq->desc)
free_rspq_fl(adapter, intrq, NULL);
}
/**
* t4vf_sge_start - enable SGE operation
* @adapter: the adapter
*
* Start tasklets and timers associated with the DMA engine.
*/
void t4vf_sge_start(struct adapter *adapter)
{
adapter->sge.ethtxq_rover = 0;
mod_timer(&adapter->sge.rx_timer, jiffies + RX_QCHECK_PERIOD);
mod_timer(&adapter->sge.tx_timer, jiffies + TX_QCHECK_PERIOD);
}
/**
* t4vf_sge_stop - disable SGE operation
* @adapter: the adapter
*
* Stop tasklets and timers associated with the DMA engine. Note that
* this is effective only if measures have been taken to disable any HW
* events that may restart them.
*/
void t4vf_sge_stop(struct adapter *adapter)
{
struct sge *s = &adapter->sge;
if (s->rx_timer.function)
del_timer_sync(&s->rx_timer);
if (s->tx_timer.function)
del_timer_sync(&s->tx_timer);
}
/**
* t4vf_sge_init - initialize SGE
* @adapter: the adapter
*
* Performs SGE initialization needed every time after a chip reset.
* We do not initialize any of the queue sets here, instead the driver
* top-level must request those individually. We also do not enable DMA
* here, that should be done after the queues have been set up.
*/
int t4vf_sge_init(struct adapter *adapter)
{
struct sge_params *sge_params = &adapter->params.sge;
u32 fl_small_pg = sge_params->sge_fl_buffer_size[0];
u32 fl_large_pg = sge_params->sge_fl_buffer_size[1];
struct sge *s = &adapter->sge;
/*
* Start by vetting the basic SGE parameters which have been set up by
* the Physical Function Driver. Ideally we should be able to deal
* with _any_ configuration. Practice is different ...
*/
/* We only bother using the Large Page logic if the Large Page Buffer
* is larger than our Page Size Buffer.
*/
if (fl_large_pg <= fl_small_pg)
fl_large_pg = 0;
/* The Page Size Buffer must be exactly equal to our Page Size and the
* Large Page Size Buffer should be 0 (per above) or a power of 2.
*/
if (fl_small_pg != PAGE_SIZE ||
(fl_large_pg & (fl_large_pg - 1)) != 0) {
dev_err(adapter->pdev_dev, "bad SGE FL buffer sizes [%d, %d]\n",
fl_small_pg, fl_large_pg);
return -EINVAL;
}
if ((sge_params->sge_control & RXPKTCPLMODE_F) !=
RXPKTCPLMODE_V(RXPKTCPLMODE_SPLIT_X)) {
dev_err(adapter->pdev_dev, "bad SGE CPL MODE\n");
return -EINVAL;
}
/*
* Now translate the adapter parameters into our internal forms.
*/
if (fl_large_pg)
s->fl_pg_order = ilog2(fl_large_pg) - PAGE_SHIFT;
s->stat_len = ((sge_params->sge_control & EGRSTATUSPAGESIZE_F)
? 128 : 64);
s->pktshift = PKTSHIFT_G(sge_params->sge_control);
s->fl_align = t4vf_fl_pkt_align(adapter);
/* A FL with <= fl_starve_thres buffers is starving and a periodic
* timer will attempt to refill it. This needs to be larger than the
* SGE's Egress Congestion Threshold. If it isn't, then we can get
* stuck waiting for new packets while the SGE is waiting for us to
* give it more Free List entries. (Note that the SGE's Egress
* Congestion Threshold is in units of 2 Free List pointers.)
*/
switch (CHELSIO_CHIP_VERSION(adapter->params.chip)) {
case CHELSIO_T4:
s->fl_starve_thres =
EGRTHRESHOLD_G(sge_params->sge_congestion_control);
break;
case CHELSIO_T5:
s->fl_starve_thres =
EGRTHRESHOLDPACKING_G(sge_params->sge_congestion_control);
break;
case CHELSIO_T6:
default:
s->fl_starve_thres =
T6_EGRTHRESHOLDPACKING_G(sge_params->sge_congestion_control);
break;
}
s->fl_starve_thres = s->fl_starve_thres * 2 + 1;
/*
* Set up tasklet timers.
*/
timer_setup(&s->rx_timer, sge_rx_timer_cb, 0);
timer_setup(&s->tx_timer, sge_tx_timer_cb, 0);
/*
* Initialize Forwarded Interrupt Queue lock.
*/
spin_lock_init(&s->intrq_lock);
return 0;
}
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