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linux-zen-server/drivers/hwtracing/coresight/coresight-tmc-etr.c

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2023-08-30 17:53:23 +02:00
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright(C) 2016 Linaro Limited. All rights reserved.
* Author: Mathieu Poirier <mathieu.poirier@linaro.org>
*/
#include <linux/atomic.h>
#include <linux/coresight.h>
#include <linux/dma-mapping.h>
#include <linux/iommu.h>
#include <linux/idr.h>
#include <linux/mutex.h>
#include <linux/refcount.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/vmalloc.h>
#include "coresight-catu.h"
#include "coresight-etm-perf.h"
#include "coresight-priv.h"
#include "coresight-tmc.h"
struct etr_flat_buf {
struct device *dev;
dma_addr_t daddr;
void *vaddr;
size_t size;
};
/*
* etr_perf_buffer - Perf buffer used for ETR
* @drvdata - The ETR drvdaga this buffer has been allocated for.
* @etr_buf - Actual buffer used by the ETR
* @pid - The PID this etr_perf_buffer belongs to.
* @snaphost - Perf session mode
* @nr_pages - Number of pages in the ring buffer.
* @pages - Array of Pages in the ring buffer.
*/
struct etr_perf_buffer {
struct tmc_drvdata *drvdata;
struct etr_buf *etr_buf;
pid_t pid;
bool snapshot;
int nr_pages;
void **pages;
};
/* Convert the perf index to an offset within the ETR buffer */
#define PERF_IDX2OFF(idx, buf) ((idx) % ((buf)->nr_pages << PAGE_SHIFT))
/* Lower limit for ETR hardware buffer */
#define TMC_ETR_PERF_MIN_BUF_SIZE SZ_1M
/*
* The TMC ETR SG has a page size of 4K. The SG table contains pointers
* to 4KB buffers. However, the OS may use a PAGE_SIZE different from
* 4K (i.e, 16KB or 64KB). This implies that a single OS page could
* contain more than one SG buffer and tables.
*
* A table entry has the following format:
*
* ---Bit31------------Bit4-------Bit1-----Bit0--
* | Address[39:12] | SBZ | Entry Type |
* ----------------------------------------------
*
* Address: Bits [39:12] of a physical page address. Bits [11:0] are
* always zero.
*
* Entry type:
* b00 - Reserved.
* b01 - Last entry in the tables, points to 4K page buffer.
* b10 - Normal entry, points to 4K page buffer.
* b11 - Link. The address points to the base of next table.
*/
typedef u32 sgte_t;
#define ETR_SG_PAGE_SHIFT 12
#define ETR_SG_PAGE_SIZE (1UL << ETR_SG_PAGE_SHIFT)
#define ETR_SG_PAGES_PER_SYSPAGE (PAGE_SIZE / ETR_SG_PAGE_SIZE)
#define ETR_SG_PTRS_PER_PAGE (ETR_SG_PAGE_SIZE / sizeof(sgte_t))
#define ETR_SG_PTRS_PER_SYSPAGE (PAGE_SIZE / sizeof(sgte_t))
#define ETR_SG_ET_MASK 0x3
#define ETR_SG_ET_LAST 0x1
#define ETR_SG_ET_NORMAL 0x2
#define ETR_SG_ET_LINK 0x3
#define ETR_SG_ADDR_SHIFT 4
#define ETR_SG_ENTRY(addr, type) \
(sgte_t)((((addr) >> ETR_SG_PAGE_SHIFT) << ETR_SG_ADDR_SHIFT) | \
(type & ETR_SG_ET_MASK))
#define ETR_SG_ADDR(entry) \
(((dma_addr_t)(entry) >> ETR_SG_ADDR_SHIFT) << ETR_SG_PAGE_SHIFT)
#define ETR_SG_ET(entry) ((entry) & ETR_SG_ET_MASK)
/*
* struct etr_sg_table : ETR SG Table
* @sg_table: Generic SG Table holding the data/table pages.
* @hwaddr: hwaddress used by the TMC, which is the base
* address of the table.
*/
struct etr_sg_table {
struct tmc_sg_table *sg_table;
dma_addr_t hwaddr;
};
/*
* tmc_etr_sg_table_entries: Total number of table entries required to map
* @nr_pages system pages.
*
* We need to map @nr_pages * ETR_SG_PAGES_PER_SYSPAGE data pages.
* Each TMC page can map (ETR_SG_PTRS_PER_PAGE - 1) buffer pointers,
* with the last entry pointing to another page of table entries.
* If we spill over to a new page for mapping 1 entry, we could as
* well replace the link entry of the previous page with the last entry.
*/
static inline unsigned long __attribute_const__
tmc_etr_sg_table_entries(int nr_pages)
{
unsigned long nr_sgpages = nr_pages * ETR_SG_PAGES_PER_SYSPAGE;
unsigned long nr_sglinks = nr_sgpages / (ETR_SG_PTRS_PER_PAGE - 1);
/*
* If we spill over to a new page for 1 entry, we could as well
* make it the LAST entry in the previous page, skipping the Link
* address.
*/
if (nr_sglinks && (nr_sgpages % (ETR_SG_PTRS_PER_PAGE - 1) < 2))
nr_sglinks--;
return nr_sgpages + nr_sglinks;
}
/*
* tmc_pages_get_offset: Go through all the pages in the tmc_pages
* and map the device address @addr to an offset within the virtual
* contiguous buffer.
*/
static long
tmc_pages_get_offset(struct tmc_pages *tmc_pages, dma_addr_t addr)
{
int i;
dma_addr_t page_start;
for (i = 0; i < tmc_pages->nr_pages; i++) {
page_start = tmc_pages->daddrs[i];
if (addr >= page_start && addr < (page_start + PAGE_SIZE))
return i * PAGE_SIZE + (addr - page_start);
}
return -EINVAL;
}
/*
* tmc_pages_free : Unmap and free the pages used by tmc_pages.
* If the pages were not allocated in tmc_pages_alloc(), we would
* simply drop the refcount.
*/
static void tmc_pages_free(struct tmc_pages *tmc_pages,
struct device *dev, enum dma_data_direction dir)
{
int i;
struct device *real_dev = dev->parent;
for (i = 0; i < tmc_pages->nr_pages; i++) {
if (tmc_pages->daddrs && tmc_pages->daddrs[i])
dma_unmap_page(real_dev, tmc_pages->daddrs[i],
PAGE_SIZE, dir);
if (tmc_pages->pages && tmc_pages->pages[i])
__free_page(tmc_pages->pages[i]);
}
kfree(tmc_pages->pages);
kfree(tmc_pages->daddrs);
tmc_pages->pages = NULL;
tmc_pages->daddrs = NULL;
tmc_pages->nr_pages = 0;
}
/*
* tmc_pages_alloc : Allocate and map pages for a given @tmc_pages.
* If @pages is not NULL, the list of page virtual addresses are
* used as the data pages. The pages are then dma_map'ed for @dev
* with dma_direction @dir.
*
* Returns 0 upon success, else the error number.
*/
static int tmc_pages_alloc(struct tmc_pages *tmc_pages,
struct device *dev, int node,
enum dma_data_direction dir, void **pages)
{
int i, nr_pages;
dma_addr_t paddr;
struct page *page;
struct device *real_dev = dev->parent;
nr_pages = tmc_pages->nr_pages;
tmc_pages->daddrs = kcalloc(nr_pages, sizeof(*tmc_pages->daddrs),
GFP_KERNEL);
if (!tmc_pages->daddrs)
return -ENOMEM;
tmc_pages->pages = kcalloc(nr_pages, sizeof(*tmc_pages->pages),
GFP_KERNEL);
if (!tmc_pages->pages) {
kfree(tmc_pages->daddrs);
tmc_pages->daddrs = NULL;
return -ENOMEM;
}
for (i = 0; i < nr_pages; i++) {
if (pages && pages[i]) {
page = virt_to_page(pages[i]);
/* Hold a refcount on the page */
get_page(page);
} else {
page = alloc_pages_node(node,
GFP_KERNEL | __GFP_ZERO, 0);
if (!page)
goto err;
}
paddr = dma_map_page(real_dev, page, 0, PAGE_SIZE, dir);
if (dma_mapping_error(real_dev, paddr))
goto err;
tmc_pages->daddrs[i] = paddr;
tmc_pages->pages[i] = page;
}
return 0;
err:
tmc_pages_free(tmc_pages, dev, dir);
return -ENOMEM;
}
static inline long
tmc_sg_get_data_page_offset(struct tmc_sg_table *sg_table, dma_addr_t addr)
{
return tmc_pages_get_offset(&sg_table->data_pages, addr);
}
static inline void tmc_free_table_pages(struct tmc_sg_table *sg_table)
{
if (sg_table->table_vaddr)
vunmap(sg_table->table_vaddr);
tmc_pages_free(&sg_table->table_pages, sg_table->dev, DMA_TO_DEVICE);
}
static void tmc_free_data_pages(struct tmc_sg_table *sg_table)
{
if (sg_table->data_vaddr)
vunmap(sg_table->data_vaddr);
tmc_pages_free(&sg_table->data_pages, sg_table->dev, DMA_FROM_DEVICE);
}
void tmc_free_sg_table(struct tmc_sg_table *sg_table)
{
tmc_free_table_pages(sg_table);
tmc_free_data_pages(sg_table);
}
EXPORT_SYMBOL_GPL(tmc_free_sg_table);
/*
* Alloc pages for the table. Since this will be used by the device,
* allocate the pages closer to the device (i.e, dev_to_node(dev)
* rather than the CPU node).
*/
static int tmc_alloc_table_pages(struct tmc_sg_table *sg_table)
{
int rc;
struct tmc_pages *table_pages = &sg_table->table_pages;
rc = tmc_pages_alloc(table_pages, sg_table->dev,
dev_to_node(sg_table->dev),
DMA_TO_DEVICE, NULL);
if (rc)
return rc;
sg_table->table_vaddr = vmap(table_pages->pages,
table_pages->nr_pages,
VM_MAP,
PAGE_KERNEL);
if (!sg_table->table_vaddr)
rc = -ENOMEM;
else
sg_table->table_daddr = table_pages->daddrs[0];
return rc;
}
static int tmc_alloc_data_pages(struct tmc_sg_table *sg_table, void **pages)
{
int rc;
/* Allocate data pages on the node requested by the caller */
rc = tmc_pages_alloc(&sg_table->data_pages,
sg_table->dev, sg_table->node,
DMA_FROM_DEVICE, pages);
if (!rc) {
sg_table->data_vaddr = vmap(sg_table->data_pages.pages,
sg_table->data_pages.nr_pages,
VM_MAP,
PAGE_KERNEL);
if (!sg_table->data_vaddr)
rc = -ENOMEM;
}
return rc;
}
/*
* tmc_alloc_sg_table: Allocate and setup dma pages for the TMC SG table
* and data buffers. TMC writes to the data buffers and reads from the SG
* Table pages.
*
* @dev - Coresight device to which page should be DMA mapped.
* @node - Numa node for mem allocations
* @nr_tpages - Number of pages for the table entries.
* @nr_dpages - Number of pages for Data buffer.
* @pages - Optional list of virtual address of pages.
*/
struct tmc_sg_table *tmc_alloc_sg_table(struct device *dev,
int node,
int nr_tpages,
int nr_dpages,
void **pages)
{
long rc;
struct tmc_sg_table *sg_table;
sg_table = kzalloc(sizeof(*sg_table), GFP_KERNEL);
if (!sg_table)
return ERR_PTR(-ENOMEM);
sg_table->data_pages.nr_pages = nr_dpages;
sg_table->table_pages.nr_pages = nr_tpages;
sg_table->node = node;
sg_table->dev = dev;
rc = tmc_alloc_data_pages(sg_table, pages);
if (!rc)
rc = tmc_alloc_table_pages(sg_table);
if (rc) {
tmc_free_sg_table(sg_table);
kfree(sg_table);
return ERR_PTR(rc);
}
return sg_table;
}
EXPORT_SYMBOL_GPL(tmc_alloc_sg_table);
/*
* tmc_sg_table_sync_data_range: Sync the data buffer written
* by the device from @offset upto a @size bytes.
*/
void tmc_sg_table_sync_data_range(struct tmc_sg_table *table,
u64 offset, u64 size)
{
int i, index, start;
int npages = DIV_ROUND_UP(size, PAGE_SIZE);
struct device *real_dev = table->dev->parent;
struct tmc_pages *data = &table->data_pages;
start = offset >> PAGE_SHIFT;
for (i = start; i < (start + npages); i++) {
index = i % data->nr_pages;
dma_sync_single_for_cpu(real_dev, data->daddrs[index],
PAGE_SIZE, DMA_FROM_DEVICE);
}
}
EXPORT_SYMBOL_GPL(tmc_sg_table_sync_data_range);
/* tmc_sg_sync_table: Sync the page table */
void tmc_sg_table_sync_table(struct tmc_sg_table *sg_table)
{
int i;
struct device *real_dev = sg_table->dev->parent;
struct tmc_pages *table_pages = &sg_table->table_pages;
for (i = 0; i < table_pages->nr_pages; i++)
dma_sync_single_for_device(real_dev, table_pages->daddrs[i],
PAGE_SIZE, DMA_TO_DEVICE);
}
EXPORT_SYMBOL_GPL(tmc_sg_table_sync_table);
/*
* tmc_sg_table_get_data: Get the buffer pointer for data @offset
* in the SG buffer. The @bufpp is updated to point to the buffer.
* Returns :
* the length of linear data available at @offset.
* or
* <= 0 if no data is available.
*/
ssize_t tmc_sg_table_get_data(struct tmc_sg_table *sg_table,
u64 offset, size_t len, char **bufpp)
{
size_t size;
int pg_idx = offset >> PAGE_SHIFT;
int pg_offset = offset & (PAGE_SIZE - 1);
struct tmc_pages *data_pages = &sg_table->data_pages;
size = tmc_sg_table_buf_size(sg_table);
if (offset >= size)
return -EINVAL;
/* Make sure we don't go beyond the end */
len = (len < (size - offset)) ? len : size - offset;
/* Respect the page boundaries */
len = (len < (PAGE_SIZE - pg_offset)) ? len : (PAGE_SIZE - pg_offset);
if (len > 0)
*bufpp = page_address(data_pages->pages[pg_idx]) + pg_offset;
return len;
}
EXPORT_SYMBOL_GPL(tmc_sg_table_get_data);
#ifdef ETR_SG_DEBUG
/* Map a dma address to virtual address */
static unsigned long
tmc_sg_daddr_to_vaddr(struct tmc_sg_table *sg_table,
dma_addr_t addr, bool table)
{
long offset;
unsigned long base;
struct tmc_pages *tmc_pages;
if (table) {
tmc_pages = &sg_table->table_pages;
base = (unsigned long)sg_table->table_vaddr;
} else {
tmc_pages = &sg_table->data_pages;
base = (unsigned long)sg_table->data_vaddr;
}
offset = tmc_pages_get_offset(tmc_pages, addr);
if (offset < 0)
return 0;
return base + offset;
}
/* Dump the given sg_table */
static void tmc_etr_sg_table_dump(struct etr_sg_table *etr_table)
{
sgte_t *ptr;
int i = 0;
dma_addr_t addr;
struct tmc_sg_table *sg_table = etr_table->sg_table;
ptr = (sgte_t *)tmc_sg_daddr_to_vaddr(sg_table,
etr_table->hwaddr, true);
while (ptr) {
addr = ETR_SG_ADDR(*ptr);
switch (ETR_SG_ET(*ptr)) {
case ETR_SG_ET_NORMAL:
dev_dbg(sg_table->dev,
"%05d: %p\t:[N] 0x%llx\n", i, ptr, addr);
ptr++;
break;
case ETR_SG_ET_LINK:
dev_dbg(sg_table->dev,
"%05d: *** %p\t:{L} 0x%llx ***\n",
i, ptr, addr);
ptr = (sgte_t *)tmc_sg_daddr_to_vaddr(sg_table,
addr, true);
break;
case ETR_SG_ET_LAST:
dev_dbg(sg_table->dev,
"%05d: ### %p\t:[L] 0x%llx ###\n",
i, ptr, addr);
return;
default:
dev_dbg(sg_table->dev,
"%05d: xxx %p\t:[INVALID] 0x%llx xxx\n",
i, ptr, addr);
return;
}
i++;
}
dev_dbg(sg_table->dev, "******* End of Table *****\n");
}
#else
static inline void tmc_etr_sg_table_dump(struct etr_sg_table *etr_table) {}
#endif
/*
* Populate the SG Table page table entries from table/data
* pages allocated. Each Data page has ETR_SG_PAGES_PER_SYSPAGE SG pages.
* So does a Table page. So we keep track of indices of the tables
* in each system page and move the pointers accordingly.
*/
#define INC_IDX_ROUND(idx, size) ((idx) = ((idx) + 1) % (size))
static void tmc_etr_sg_table_populate(struct etr_sg_table *etr_table)
{
dma_addr_t paddr;
int i, type, nr_entries;
int tpidx = 0; /* index to the current system table_page */
int sgtidx = 0; /* index to the sg_table within the current syspage */
int sgtentry = 0; /* the entry within the sg_table */
int dpidx = 0; /* index to the current system data_page */
int spidx = 0; /* index to the SG page within the current data page */
sgte_t *ptr; /* pointer to the table entry to fill */
struct tmc_sg_table *sg_table = etr_table->sg_table;
dma_addr_t *table_daddrs = sg_table->table_pages.daddrs;
dma_addr_t *data_daddrs = sg_table->data_pages.daddrs;
nr_entries = tmc_etr_sg_table_entries(sg_table->data_pages.nr_pages);
/*
* Use the contiguous virtual address of the table to update entries.
*/
ptr = sg_table->table_vaddr;
/*
* Fill all the entries, except the last entry to avoid special
* checks within the loop.
*/
for (i = 0; i < nr_entries - 1; i++) {
if (sgtentry == ETR_SG_PTRS_PER_PAGE - 1) {
/*
* Last entry in a sg_table page is a link address to
* the next table page. If this sg_table is the last
* one in the system page, it links to the first
* sg_table in the next system page. Otherwise, it
* links to the next sg_table page within the system
* page.
*/
if (sgtidx == ETR_SG_PAGES_PER_SYSPAGE - 1) {
paddr = table_daddrs[tpidx + 1];
} else {
paddr = table_daddrs[tpidx] +
(ETR_SG_PAGE_SIZE * (sgtidx + 1));
}
type = ETR_SG_ET_LINK;
} else {
/*
* Update the indices to the data_pages to point to the
* next sg_page in the data buffer.
*/
type = ETR_SG_ET_NORMAL;
paddr = data_daddrs[dpidx] + spidx * ETR_SG_PAGE_SIZE;
if (!INC_IDX_ROUND(spidx, ETR_SG_PAGES_PER_SYSPAGE))
dpidx++;
}
*ptr++ = ETR_SG_ENTRY(paddr, type);
/*
* Move to the next table pointer, moving the table page index
* if necessary
*/
if (!INC_IDX_ROUND(sgtentry, ETR_SG_PTRS_PER_PAGE)) {
if (!INC_IDX_ROUND(sgtidx, ETR_SG_PAGES_PER_SYSPAGE))
tpidx++;
}
}
/* Set up the last entry, which is always a data pointer */
paddr = data_daddrs[dpidx] + spidx * ETR_SG_PAGE_SIZE;
*ptr++ = ETR_SG_ENTRY(paddr, ETR_SG_ET_LAST);
}
/*
* tmc_init_etr_sg_table: Allocate a TMC ETR SG table, data buffer of @size and
* populate the table.
*
* @dev - Device pointer for the TMC
* @node - NUMA node where the memory should be allocated
* @size - Total size of the data buffer
* @pages - Optional list of page virtual address
*/
static struct etr_sg_table *
tmc_init_etr_sg_table(struct device *dev, int node,
unsigned long size, void **pages)
{
int nr_entries, nr_tpages;
int nr_dpages = size >> PAGE_SHIFT;
struct tmc_sg_table *sg_table;
struct etr_sg_table *etr_table;
etr_table = kzalloc(sizeof(*etr_table), GFP_KERNEL);
if (!etr_table)
return ERR_PTR(-ENOMEM);
nr_entries = tmc_etr_sg_table_entries(nr_dpages);
nr_tpages = DIV_ROUND_UP(nr_entries, ETR_SG_PTRS_PER_SYSPAGE);
sg_table = tmc_alloc_sg_table(dev, node, nr_tpages, nr_dpages, pages);
if (IS_ERR(sg_table)) {
kfree(etr_table);
return ERR_CAST(sg_table);
}
etr_table->sg_table = sg_table;
/* TMC should use table base address for DBA */
etr_table->hwaddr = sg_table->table_daddr;
tmc_etr_sg_table_populate(etr_table);
/* Sync the table pages for the HW */
tmc_sg_table_sync_table(sg_table);
tmc_etr_sg_table_dump(etr_table);
return etr_table;
}
/*
* tmc_etr_alloc_flat_buf: Allocate a contiguous DMA buffer.
*/
static int tmc_etr_alloc_flat_buf(struct tmc_drvdata *drvdata,
struct etr_buf *etr_buf, int node,
void **pages)
{
struct etr_flat_buf *flat_buf;
struct device *real_dev = drvdata->csdev->dev.parent;
/* We cannot reuse existing pages for flat buf */
if (pages)
return -EINVAL;
flat_buf = kzalloc(sizeof(*flat_buf), GFP_KERNEL);
if (!flat_buf)
return -ENOMEM;
flat_buf->vaddr = dma_alloc_noncoherent(real_dev, etr_buf->size,
&flat_buf->daddr,
DMA_FROM_DEVICE, GFP_KERNEL);
if (!flat_buf->vaddr) {
kfree(flat_buf);
return -ENOMEM;
}
flat_buf->size = etr_buf->size;
flat_buf->dev = &drvdata->csdev->dev;
etr_buf->hwaddr = flat_buf->daddr;
etr_buf->mode = ETR_MODE_FLAT;
etr_buf->private = flat_buf;
return 0;
}
static void tmc_etr_free_flat_buf(struct etr_buf *etr_buf)
{
struct etr_flat_buf *flat_buf = etr_buf->private;
if (flat_buf && flat_buf->daddr) {
struct device *real_dev = flat_buf->dev->parent;
dma_free_noncoherent(real_dev, etr_buf->size,
flat_buf->vaddr, flat_buf->daddr,
DMA_FROM_DEVICE);
}
kfree(flat_buf);
}
static void tmc_etr_sync_flat_buf(struct etr_buf *etr_buf, u64 rrp, u64 rwp)
{
struct etr_flat_buf *flat_buf = etr_buf->private;
struct device *real_dev = flat_buf->dev->parent;
/*
* Adjust the buffer to point to the beginning of the trace data
* and update the available trace data.
*/
etr_buf->offset = rrp - etr_buf->hwaddr;
if (etr_buf->full)
etr_buf->len = etr_buf->size;
else
etr_buf->len = rwp - rrp;
/*
* The driver always starts tracing at the beginning of the buffer,
* the only reason why we would get a wrap around is when the buffer
* is full. Sync the entire buffer in one go for this case.
*/
if (etr_buf->offset + etr_buf->len > etr_buf->size)
dma_sync_single_for_cpu(real_dev, flat_buf->daddr,
etr_buf->size, DMA_FROM_DEVICE);
else
dma_sync_single_for_cpu(real_dev,
flat_buf->daddr + etr_buf->offset,
etr_buf->len, DMA_FROM_DEVICE);
}
static ssize_t tmc_etr_get_data_flat_buf(struct etr_buf *etr_buf,
u64 offset, size_t len, char **bufpp)
{
struct etr_flat_buf *flat_buf = etr_buf->private;
*bufpp = (char *)flat_buf->vaddr + offset;
/*
* tmc_etr_buf_get_data already adjusts the length to handle
* buffer wrapping around.
*/
return len;
}
static const struct etr_buf_operations etr_flat_buf_ops = {
.alloc = tmc_etr_alloc_flat_buf,
.free = tmc_etr_free_flat_buf,
.sync = tmc_etr_sync_flat_buf,
.get_data = tmc_etr_get_data_flat_buf,
};
/*
* tmc_etr_alloc_sg_buf: Allocate an SG buf @etr_buf. Setup the parameters
* appropriately.
*/
static int tmc_etr_alloc_sg_buf(struct tmc_drvdata *drvdata,
struct etr_buf *etr_buf, int node,
void **pages)
{
struct etr_sg_table *etr_table;
struct device *dev = &drvdata->csdev->dev;
etr_table = tmc_init_etr_sg_table(dev, node,
etr_buf->size, pages);
if (IS_ERR(etr_table))
return -ENOMEM;
etr_buf->hwaddr = etr_table->hwaddr;
etr_buf->mode = ETR_MODE_ETR_SG;
etr_buf->private = etr_table;
return 0;
}
static void tmc_etr_free_sg_buf(struct etr_buf *etr_buf)
{
struct etr_sg_table *etr_table = etr_buf->private;
if (etr_table) {
tmc_free_sg_table(etr_table->sg_table);
kfree(etr_table);
}
}
static ssize_t tmc_etr_get_data_sg_buf(struct etr_buf *etr_buf, u64 offset,
size_t len, char **bufpp)
{
struct etr_sg_table *etr_table = etr_buf->private;
return tmc_sg_table_get_data(etr_table->sg_table, offset, len, bufpp);
}
static void tmc_etr_sync_sg_buf(struct etr_buf *etr_buf, u64 rrp, u64 rwp)
{
long r_offset, w_offset;
struct etr_sg_table *etr_table = etr_buf->private;
struct tmc_sg_table *table = etr_table->sg_table;
/* Convert hw address to offset in the buffer */
r_offset = tmc_sg_get_data_page_offset(table, rrp);
if (r_offset < 0) {
dev_warn(table->dev,
"Unable to map RRP %llx to offset\n", rrp);
etr_buf->len = 0;
return;
}
w_offset = tmc_sg_get_data_page_offset(table, rwp);
if (w_offset < 0) {
dev_warn(table->dev,
"Unable to map RWP %llx to offset\n", rwp);
etr_buf->len = 0;
return;
}
etr_buf->offset = r_offset;
if (etr_buf->full)
etr_buf->len = etr_buf->size;
else
etr_buf->len = ((w_offset < r_offset) ? etr_buf->size : 0) +
w_offset - r_offset;
tmc_sg_table_sync_data_range(table, r_offset, etr_buf->len);
}
static const struct etr_buf_operations etr_sg_buf_ops = {
.alloc = tmc_etr_alloc_sg_buf,
.free = tmc_etr_free_sg_buf,
.sync = tmc_etr_sync_sg_buf,
.get_data = tmc_etr_get_data_sg_buf,
};
/*
* TMC ETR could be connected to a CATU device, which can provide address
* translation service. This is represented by the Output port of the TMC
* (ETR) connected to the input port of the CATU.
*
* Returns : coresight_device ptr for the CATU device if a CATU is found.
* : NULL otherwise.
*/
struct coresight_device *
tmc_etr_get_catu_device(struct tmc_drvdata *drvdata)
{
int i;
struct coresight_device *tmp, *etr = drvdata->csdev;
if (!IS_ENABLED(CONFIG_CORESIGHT_CATU))
return NULL;
for (i = 0; i < etr->pdata->nr_outport; i++) {
tmp = etr->pdata->conns[i].child_dev;
if (tmp && coresight_is_catu_device(tmp))
return tmp;
}
return NULL;
}
EXPORT_SYMBOL_GPL(tmc_etr_get_catu_device);
static inline int tmc_etr_enable_catu(struct tmc_drvdata *drvdata,
struct etr_buf *etr_buf)
{
struct coresight_device *catu = tmc_etr_get_catu_device(drvdata);
if (catu && helper_ops(catu)->enable)
return helper_ops(catu)->enable(catu, etr_buf);
return 0;
}
static inline void tmc_etr_disable_catu(struct tmc_drvdata *drvdata)
{
struct coresight_device *catu = tmc_etr_get_catu_device(drvdata);
if (catu && helper_ops(catu)->disable)
helper_ops(catu)->disable(catu, drvdata->etr_buf);
}
static const struct etr_buf_operations *etr_buf_ops[] = {
[ETR_MODE_FLAT] = &etr_flat_buf_ops,
[ETR_MODE_ETR_SG] = &etr_sg_buf_ops,
[ETR_MODE_CATU] = NULL,
};
void tmc_etr_set_catu_ops(const struct etr_buf_operations *catu)
{
etr_buf_ops[ETR_MODE_CATU] = catu;
}
EXPORT_SYMBOL_GPL(tmc_etr_set_catu_ops);
void tmc_etr_remove_catu_ops(void)
{
etr_buf_ops[ETR_MODE_CATU] = NULL;
}
EXPORT_SYMBOL_GPL(tmc_etr_remove_catu_ops);
static inline int tmc_etr_mode_alloc_buf(int mode,
struct tmc_drvdata *drvdata,
struct etr_buf *etr_buf, int node,
void **pages)
{
int rc = -EINVAL;
switch (mode) {
case ETR_MODE_FLAT:
case ETR_MODE_ETR_SG:
case ETR_MODE_CATU:
if (etr_buf_ops[mode] && etr_buf_ops[mode]->alloc)
rc = etr_buf_ops[mode]->alloc(drvdata, etr_buf,
node, pages);
if (!rc)
etr_buf->ops = etr_buf_ops[mode];
return rc;
default:
return -EINVAL;
}
}
/*
* tmc_alloc_etr_buf: Allocate a buffer use by ETR.
* @drvdata : ETR device details.
* @size : size of the requested buffer.
* @flags : Required properties for the buffer.
* @node : Node for memory allocations.
* @pages : An optional list of pages.
*/
static struct etr_buf *tmc_alloc_etr_buf(struct tmc_drvdata *drvdata,
ssize_t size, int flags,
int node, void **pages)
{
int rc = -ENOMEM;
bool has_etr_sg, has_iommu;
bool has_sg, has_catu;
struct etr_buf *etr_buf;
struct device *dev = &drvdata->csdev->dev;
has_etr_sg = tmc_etr_has_cap(drvdata, TMC_ETR_SG);
has_iommu = iommu_get_domain_for_dev(dev->parent);
has_catu = !!tmc_etr_get_catu_device(drvdata);
has_sg = has_catu || has_etr_sg;
etr_buf = kzalloc(sizeof(*etr_buf), GFP_KERNEL);
if (!etr_buf)
return ERR_PTR(-ENOMEM);
etr_buf->size = size;
/*
* If we have to use an existing list of pages, we cannot reliably
* use a contiguous DMA memory (even if we have an IOMMU). Otherwise,
* we use the contiguous DMA memory if at least one of the following
* conditions is true:
* a) The ETR cannot use Scatter-Gather.
* b) we have a backing IOMMU
* c) The requested memory size is smaller (< 1M).
*
* Fallback to available mechanisms.
*
*/
if (!pages &&
(!has_sg || has_iommu || size < SZ_1M))
rc = tmc_etr_mode_alloc_buf(ETR_MODE_FLAT, drvdata,
etr_buf, node, pages);
if (rc && has_etr_sg)
rc = tmc_etr_mode_alloc_buf(ETR_MODE_ETR_SG, drvdata,
etr_buf, node, pages);
if (rc && has_catu)
rc = tmc_etr_mode_alloc_buf(ETR_MODE_CATU, drvdata,
etr_buf, node, pages);
if (rc) {
kfree(etr_buf);
return ERR_PTR(rc);
}
refcount_set(&etr_buf->refcount, 1);
dev_dbg(dev, "allocated buffer of size %ldKB in mode %d\n",
(unsigned long)size >> 10, etr_buf->mode);
return etr_buf;
}
static void tmc_free_etr_buf(struct etr_buf *etr_buf)
{
WARN_ON(!etr_buf->ops || !etr_buf->ops->free);
etr_buf->ops->free(etr_buf);
kfree(etr_buf);
}
/*
* tmc_etr_buf_get_data: Get the pointer the trace data at @offset
* with a maximum of @len bytes.
* Returns: The size of the linear data available @pos, with *bufpp
* updated to point to the buffer.
*/
static ssize_t tmc_etr_buf_get_data(struct etr_buf *etr_buf,
u64 offset, size_t len, char **bufpp)
{
/* Adjust the length to limit this transaction to end of buffer */
len = (len < (etr_buf->size - offset)) ? len : etr_buf->size - offset;
return etr_buf->ops->get_data(etr_buf, (u64)offset, len, bufpp);
}
static inline s64
tmc_etr_buf_insert_barrier_packet(struct etr_buf *etr_buf, u64 offset)
{
ssize_t len;
char *bufp;
len = tmc_etr_buf_get_data(etr_buf, offset,
CORESIGHT_BARRIER_PKT_SIZE, &bufp);
if (WARN_ON(len < 0 || len < CORESIGHT_BARRIER_PKT_SIZE))
return -EINVAL;
coresight_insert_barrier_packet(bufp);
return offset + CORESIGHT_BARRIER_PKT_SIZE;
}
/*
* tmc_sync_etr_buf: Sync the trace buffer availability with drvdata.
* Makes sure the trace data is synced to the memory for consumption.
* @etr_buf->offset will hold the offset to the beginning of the trace data
* within the buffer, with @etr_buf->len bytes to consume.
*/
static void tmc_sync_etr_buf(struct tmc_drvdata *drvdata)
{
struct etr_buf *etr_buf = drvdata->etr_buf;
u64 rrp, rwp;
u32 status;
rrp = tmc_read_rrp(drvdata);
rwp = tmc_read_rwp(drvdata);
status = readl_relaxed(drvdata->base + TMC_STS);
/*
* If there were memory errors in the session, truncate the
* buffer.
*/
if (WARN_ON_ONCE(status & TMC_STS_MEMERR)) {
dev_dbg(&drvdata->csdev->dev,
"tmc memory error detected, truncating buffer\n");
etr_buf->len = 0;
etr_buf->full = false;
return;
}
etr_buf->full = !!(status & TMC_STS_FULL);
WARN_ON(!etr_buf->ops || !etr_buf->ops->sync);
etr_buf->ops->sync(etr_buf, rrp, rwp);
}
static int __tmc_etr_enable_hw(struct tmc_drvdata *drvdata)
{
u32 axictl, sts;
struct etr_buf *etr_buf = drvdata->etr_buf;
int rc = 0;
CS_UNLOCK(drvdata->base);
/* Wait for TMCSReady bit to be set */
rc = tmc_wait_for_tmcready(drvdata);
if (rc) {
dev_err(&drvdata->csdev->dev,
"Failed to enable : TMC not ready\n");
CS_LOCK(drvdata->base);
return rc;
}
writel_relaxed(etr_buf->size / 4, drvdata->base + TMC_RSZ);
writel_relaxed(TMC_MODE_CIRCULAR_BUFFER, drvdata->base + TMC_MODE);
axictl = readl_relaxed(drvdata->base + TMC_AXICTL);
axictl &= ~TMC_AXICTL_CLEAR_MASK;
axictl |= TMC_AXICTL_PROT_CTL_B1;
axictl |= TMC_AXICTL_WR_BURST(drvdata->max_burst_size);
axictl |= TMC_AXICTL_AXCACHE_OS;
if (tmc_etr_has_cap(drvdata, TMC_ETR_AXI_ARCACHE)) {
axictl &= ~TMC_AXICTL_ARCACHE_MASK;
axictl |= TMC_AXICTL_ARCACHE_OS;
}
if (etr_buf->mode == ETR_MODE_ETR_SG)
axictl |= TMC_AXICTL_SCT_GAT_MODE;
writel_relaxed(axictl, drvdata->base + TMC_AXICTL);
tmc_write_dba(drvdata, etr_buf->hwaddr);
/*
* If the TMC pointers must be programmed before the session,
* we have to set it properly (i.e, RRP/RWP to base address and
* STS to "not full").
*/
if (tmc_etr_has_cap(drvdata, TMC_ETR_SAVE_RESTORE)) {
tmc_write_rrp(drvdata, etr_buf->hwaddr);
tmc_write_rwp(drvdata, etr_buf->hwaddr);
sts = readl_relaxed(drvdata->base + TMC_STS) & ~TMC_STS_FULL;
writel_relaxed(sts, drvdata->base + TMC_STS);
}
writel_relaxed(TMC_FFCR_EN_FMT | TMC_FFCR_EN_TI |
TMC_FFCR_FON_FLIN | TMC_FFCR_FON_TRIG_EVT |
TMC_FFCR_TRIGON_TRIGIN,
drvdata->base + TMC_FFCR);
writel_relaxed(drvdata->trigger_cntr, drvdata->base + TMC_TRG);
tmc_enable_hw(drvdata);
CS_LOCK(drvdata->base);
return rc;
}
static int tmc_etr_enable_hw(struct tmc_drvdata *drvdata,
struct etr_buf *etr_buf)
{
int rc;
/* Callers should provide an appropriate buffer for use */
if (WARN_ON(!etr_buf))
return -EINVAL;
if ((etr_buf->mode == ETR_MODE_ETR_SG) &&
WARN_ON(!tmc_etr_has_cap(drvdata, TMC_ETR_SG)))
return -EINVAL;
if (WARN_ON(drvdata->etr_buf))
return -EBUSY;
/*
* If this ETR is connected to a CATU, enable it before we turn
* this on.
*/
rc = tmc_etr_enable_catu(drvdata, etr_buf);
if (rc)
return rc;
rc = coresight_claim_device(drvdata->csdev);
if (!rc) {
drvdata->etr_buf = etr_buf;
rc = __tmc_etr_enable_hw(drvdata);
if (rc) {
drvdata->etr_buf = NULL;
coresight_disclaim_device(drvdata->csdev);
tmc_etr_disable_catu(drvdata);
}
}
return rc;
}
/*
* Return the available trace data in the buffer (starts at etr_buf->offset,
* limited by etr_buf->len) from @pos, with a maximum limit of @len,
* also updating the @bufpp on where to find it. Since the trace data
* starts at anywhere in the buffer, depending on the RRP, we adjust the
* @len returned to handle buffer wrapping around.
*
* We are protected here by drvdata->reading != 0, which ensures the
* sysfs_buf stays alive.
*/
ssize_t tmc_etr_get_sysfs_trace(struct tmc_drvdata *drvdata,
loff_t pos, size_t len, char **bufpp)
{
s64 offset;
ssize_t actual = len;
struct etr_buf *etr_buf = drvdata->sysfs_buf;
if (pos + actual > etr_buf->len)
actual = etr_buf->len - pos;
if (actual <= 0)
return actual;
/* Compute the offset from which we read the data */
offset = etr_buf->offset + pos;
if (offset >= etr_buf->size)
offset -= etr_buf->size;
return tmc_etr_buf_get_data(etr_buf, offset, actual, bufpp);
}
static struct etr_buf *
tmc_etr_setup_sysfs_buf(struct tmc_drvdata *drvdata)
{
return tmc_alloc_etr_buf(drvdata, drvdata->size,
0, cpu_to_node(0), NULL);
}
static void
tmc_etr_free_sysfs_buf(struct etr_buf *buf)
{
if (buf)
tmc_free_etr_buf(buf);
}
static void tmc_etr_sync_sysfs_buf(struct tmc_drvdata *drvdata)
{
struct etr_buf *etr_buf = drvdata->etr_buf;
if (WARN_ON(drvdata->sysfs_buf != etr_buf)) {
tmc_etr_free_sysfs_buf(drvdata->sysfs_buf);
drvdata->sysfs_buf = NULL;
} else {
tmc_sync_etr_buf(drvdata);
/*
* Insert barrier packets at the beginning, if there was
* an overflow.
*/
if (etr_buf->full)
tmc_etr_buf_insert_barrier_packet(etr_buf,
etr_buf->offset);
}
}
static void __tmc_etr_disable_hw(struct tmc_drvdata *drvdata)
{
CS_UNLOCK(drvdata->base);
tmc_flush_and_stop(drvdata);
/*
* When operating in sysFS mode the content of the buffer needs to be
* read before the TMC is disabled.
*/
if (drvdata->mode == CS_MODE_SYSFS)
tmc_etr_sync_sysfs_buf(drvdata);
tmc_disable_hw(drvdata);
CS_LOCK(drvdata->base);
}
void tmc_etr_disable_hw(struct tmc_drvdata *drvdata)
{
__tmc_etr_disable_hw(drvdata);
/* Disable CATU device if this ETR is connected to one */
tmc_etr_disable_catu(drvdata);
coresight_disclaim_device(drvdata->csdev);
/* Reset the ETR buf used by hardware */
drvdata->etr_buf = NULL;
}
static int tmc_enable_etr_sink_sysfs(struct coresight_device *csdev)
{
int ret = 0;
unsigned long flags;
struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
struct etr_buf *sysfs_buf = NULL, *new_buf = NULL, *free_buf = NULL;
/*
* If we are enabling the ETR from disabled state, we need to make
* sure we have a buffer with the right size. The etr_buf is not reset
* immediately after we stop the tracing in SYSFS mode as we wait for
* the user to collect the data. We may be able to reuse the existing
* buffer, provided the size matches. Any allocation has to be done
* with the lock released.
*/
spin_lock_irqsave(&drvdata->spinlock, flags);
sysfs_buf = READ_ONCE(drvdata->sysfs_buf);
if (!sysfs_buf || (sysfs_buf->size != drvdata->size)) {
spin_unlock_irqrestore(&drvdata->spinlock, flags);
/* Allocate memory with the locks released */
free_buf = new_buf = tmc_etr_setup_sysfs_buf(drvdata);
if (IS_ERR(new_buf))
return PTR_ERR(new_buf);
/* Let's try again */
spin_lock_irqsave(&drvdata->spinlock, flags);
}
if (drvdata->reading || drvdata->mode == CS_MODE_PERF) {
ret = -EBUSY;
goto out;
}
/*
* In sysFS mode we can have multiple writers per sink. Since this
* sink is already enabled no memory is needed and the HW need not be
* touched, even if the buffer size has changed.
*/
if (drvdata->mode == CS_MODE_SYSFS) {
atomic_inc(csdev->refcnt);
goto out;
}
/*
* If we don't have a buffer or it doesn't match the requested size,
* use the buffer allocated above. Otherwise reuse the existing buffer.
*/
sysfs_buf = READ_ONCE(drvdata->sysfs_buf);
if (!sysfs_buf || (new_buf && sysfs_buf->size != new_buf->size)) {
free_buf = sysfs_buf;
drvdata->sysfs_buf = new_buf;
}
ret = tmc_etr_enable_hw(drvdata, drvdata->sysfs_buf);
if (!ret) {
drvdata->mode = CS_MODE_SYSFS;
atomic_inc(csdev->refcnt);
}
out:
spin_unlock_irqrestore(&drvdata->spinlock, flags);
/* Free memory outside the spinlock if need be */
if (free_buf)
tmc_etr_free_sysfs_buf(free_buf);
if (!ret)
dev_dbg(&csdev->dev, "TMC-ETR enabled\n");
return ret;
}
/*
* alloc_etr_buf: Allocate ETR buffer for use by perf.
* The size of the hardware buffer is dependent on the size configured
* via sysfs and the perf ring buffer size. We prefer to allocate the
* largest possible size, scaling down the size by half until it
* reaches a minimum limit (1M), beyond which we give up.
*/
static struct etr_buf *
alloc_etr_buf(struct tmc_drvdata *drvdata, struct perf_event *event,
int nr_pages, void **pages, bool snapshot)
{
int node;
struct etr_buf *etr_buf;
unsigned long size;
node = (event->cpu == -1) ? NUMA_NO_NODE : cpu_to_node(event->cpu);
/*
* Try to match the perf ring buffer size if it is larger
* than the size requested via sysfs.
*/
if ((nr_pages << PAGE_SHIFT) > drvdata->size) {
etr_buf = tmc_alloc_etr_buf(drvdata, (nr_pages << PAGE_SHIFT),
0, node, NULL);
if (!IS_ERR(etr_buf))
goto done;
}
/*
* Else switch to configured size for this ETR
* and scale down until we hit the minimum limit.
*/
size = drvdata->size;
do {
etr_buf = tmc_alloc_etr_buf(drvdata, size, 0, node, NULL);
if (!IS_ERR(etr_buf))
goto done;
size /= 2;
} while (size >= TMC_ETR_PERF_MIN_BUF_SIZE);
return ERR_PTR(-ENOMEM);
done:
return etr_buf;
}
static struct etr_buf *
get_perf_etr_buf_cpu_wide(struct tmc_drvdata *drvdata,
struct perf_event *event, int nr_pages,
void **pages, bool snapshot)
{
int ret;
pid_t pid = task_pid_nr(event->owner);
struct etr_buf *etr_buf;
retry:
/*
* An etr_perf_buffer is associated with an event and holds a reference
* to the AUX ring buffer that was created for that event. In CPU-wide
* N:1 mode multiple events (one per CPU), each with its own AUX ring
* buffer, share a sink. As such an etr_perf_buffer is created for each
* event but a single etr_buf associated with the ETR is shared between
* them. The last event in a trace session will copy the content of the
* etr_buf to its AUX ring buffer. Ring buffer associated to other
* events are simply not used an freed as events are destoyed. We still
* need to allocate a ring buffer for each event since we don't know
* which event will be last.
*/
/*
* The first thing to do here is check if an etr_buf has already been
* allocated for this session. If so it is shared with this event,
* otherwise it is created.
*/
mutex_lock(&drvdata->idr_mutex);
etr_buf = idr_find(&drvdata->idr, pid);
if (etr_buf) {
refcount_inc(&etr_buf->refcount);
mutex_unlock(&drvdata->idr_mutex);
return etr_buf;
}
/* If we made it here no buffer has been allocated, do so now. */
mutex_unlock(&drvdata->idr_mutex);
etr_buf = alloc_etr_buf(drvdata, event, nr_pages, pages, snapshot);
if (IS_ERR(etr_buf))
return etr_buf;
/* Now that we have a buffer, add it to the IDR. */
mutex_lock(&drvdata->idr_mutex);
ret = idr_alloc(&drvdata->idr, etr_buf, pid, pid + 1, GFP_KERNEL);
mutex_unlock(&drvdata->idr_mutex);
/* Another event with this session ID has allocated this buffer. */
if (ret == -ENOSPC) {
tmc_free_etr_buf(etr_buf);
goto retry;
}
/* The IDR can't allocate room for a new session, abandon ship. */
if (ret == -ENOMEM) {
tmc_free_etr_buf(etr_buf);
return ERR_PTR(ret);
}
return etr_buf;
}
static struct etr_buf *
get_perf_etr_buf_per_thread(struct tmc_drvdata *drvdata,
struct perf_event *event, int nr_pages,
void **pages, bool snapshot)
{
/*
* In per-thread mode the etr_buf isn't shared, so just go ahead
* with memory allocation.
*/
return alloc_etr_buf(drvdata, event, nr_pages, pages, snapshot);
}
static struct etr_buf *
get_perf_etr_buf(struct tmc_drvdata *drvdata, struct perf_event *event,
int nr_pages, void **pages, bool snapshot)
{
if (event->cpu == -1)
return get_perf_etr_buf_per_thread(drvdata, event, nr_pages,
pages, snapshot);
return get_perf_etr_buf_cpu_wide(drvdata, event, nr_pages,
pages, snapshot);
}
static struct etr_perf_buffer *
tmc_etr_setup_perf_buf(struct tmc_drvdata *drvdata, struct perf_event *event,
int nr_pages, void **pages, bool snapshot)
{
int node;
struct etr_buf *etr_buf;
struct etr_perf_buffer *etr_perf;
node = (event->cpu == -1) ? NUMA_NO_NODE : cpu_to_node(event->cpu);
etr_perf = kzalloc_node(sizeof(*etr_perf), GFP_KERNEL, node);
if (!etr_perf)
return ERR_PTR(-ENOMEM);
etr_buf = get_perf_etr_buf(drvdata, event, nr_pages, pages, snapshot);
if (!IS_ERR(etr_buf))
goto done;
kfree(etr_perf);
return ERR_PTR(-ENOMEM);
done:
/*
* Keep a reference to the ETR this buffer has been allocated for
* in order to have access to the IDR in tmc_free_etr_buffer().
*/
etr_perf->drvdata = drvdata;
etr_perf->etr_buf = etr_buf;
return etr_perf;
}
static void *tmc_alloc_etr_buffer(struct coresight_device *csdev,
struct perf_event *event, void **pages,
int nr_pages, bool snapshot)
{
struct etr_perf_buffer *etr_perf;
struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
etr_perf = tmc_etr_setup_perf_buf(drvdata, event,
nr_pages, pages, snapshot);
if (IS_ERR(etr_perf)) {
dev_dbg(&csdev->dev, "Unable to allocate ETR buffer\n");
return NULL;
}
etr_perf->pid = task_pid_nr(event->owner);
etr_perf->snapshot = snapshot;
etr_perf->nr_pages = nr_pages;
etr_perf->pages = pages;
return etr_perf;
}
static void tmc_free_etr_buffer(void *config)
{
struct etr_perf_buffer *etr_perf = config;
struct tmc_drvdata *drvdata = etr_perf->drvdata;
struct etr_buf *buf, *etr_buf = etr_perf->etr_buf;
if (!etr_buf)
goto free_etr_perf_buffer;
mutex_lock(&drvdata->idr_mutex);
/* If we are not the last one to use the buffer, don't touch it. */
if (!refcount_dec_and_test(&etr_buf->refcount)) {
mutex_unlock(&drvdata->idr_mutex);
goto free_etr_perf_buffer;
}
/* We are the last one, remove from the IDR and free the buffer. */
buf = idr_remove(&drvdata->idr, etr_perf->pid);
mutex_unlock(&drvdata->idr_mutex);
/*
* Something went very wrong if the buffer associated with this ID
* is not the same in the IDR. Leak to avoid use after free.
*/
if (buf && WARN_ON(buf != etr_buf))
goto free_etr_perf_buffer;
tmc_free_etr_buf(etr_perf->etr_buf);
free_etr_perf_buffer:
kfree(etr_perf);
}
/*
* tmc_etr_sync_perf_buffer: Copy the actual trace data from the hardware
* buffer to the perf ring buffer.
*/
static void tmc_etr_sync_perf_buffer(struct etr_perf_buffer *etr_perf,
unsigned long head,
unsigned long src_offset,
unsigned long to_copy)
{
long bytes;
long pg_idx, pg_offset;
char **dst_pages, *src_buf;
struct etr_buf *etr_buf = etr_perf->etr_buf;
head = PERF_IDX2OFF(head, etr_perf);
pg_idx = head >> PAGE_SHIFT;
pg_offset = head & (PAGE_SIZE - 1);
dst_pages = (char **)etr_perf->pages;
while (to_copy > 0) {
/*
* In one iteration, we can copy minimum of :
* 1) what is available in the source buffer,
* 2) what is available in the source buffer, before it
* wraps around.
* 3) what is available in the destination page.
* in one iteration.
*/
if (src_offset >= etr_buf->size)
src_offset -= etr_buf->size;
bytes = tmc_etr_buf_get_data(etr_buf, src_offset, to_copy,
&src_buf);
if (WARN_ON_ONCE(bytes <= 0))
break;
bytes = min(bytes, (long)(PAGE_SIZE - pg_offset));
memcpy(dst_pages[pg_idx] + pg_offset, src_buf, bytes);
to_copy -= bytes;
/* Move destination pointers */
pg_offset += bytes;
if (pg_offset == PAGE_SIZE) {
pg_offset = 0;
if (++pg_idx == etr_perf->nr_pages)
pg_idx = 0;
}
/* Move source pointers */
src_offset += bytes;
}
}
/*
* tmc_update_etr_buffer : Update the perf ring buffer with the
* available trace data. We use software double buffering at the moment.
*
* TODO: Add support for reusing the perf ring buffer.
*/
static unsigned long
tmc_update_etr_buffer(struct coresight_device *csdev,
struct perf_output_handle *handle,
void *config)
{
bool lost = false;
unsigned long flags, offset, size = 0;
struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
struct etr_perf_buffer *etr_perf = config;
struct etr_buf *etr_buf = etr_perf->etr_buf;
spin_lock_irqsave(&drvdata->spinlock, flags);
/* Don't do anything if another tracer is using this sink */
if (atomic_read(csdev->refcnt) != 1) {
spin_unlock_irqrestore(&drvdata->spinlock, flags);
goto out;
}
if (WARN_ON(drvdata->perf_buf != etr_buf)) {
lost = true;
spin_unlock_irqrestore(&drvdata->spinlock, flags);
goto out;
}
CS_UNLOCK(drvdata->base);
tmc_flush_and_stop(drvdata);
tmc_sync_etr_buf(drvdata);
CS_LOCK(drvdata->base);
spin_unlock_irqrestore(&drvdata->spinlock, flags);
lost = etr_buf->full;
offset = etr_buf->offset;
size = etr_buf->len;
/*
* The ETR buffer may be bigger than the space available in the
* perf ring buffer (handle->size). If so advance the offset so that we
* get the latest trace data. In snapshot mode none of that matters
* since we are expected to clobber stale data in favour of the latest
* traces.
*/
if (!etr_perf->snapshot && size > handle->size) {
u32 mask = tmc_get_memwidth_mask(drvdata);
/*
* Make sure the new size is aligned in accordance with the
* requirement explained in function tmc_get_memwidth_mask().
*/
size = handle->size & mask;
offset = etr_buf->offset + etr_buf->len - size;
if (offset >= etr_buf->size)
offset -= etr_buf->size;
lost = true;
}
/* Insert barrier packets at the beginning, if there was an overflow */
if (lost)
tmc_etr_buf_insert_barrier_packet(etr_buf, offset);
tmc_etr_sync_perf_buffer(etr_perf, handle->head, offset, size);
/*
* In snapshot mode we simply increment the head by the number of byte
* that were written. User space will figure out how many bytes to get
* from the AUX buffer based on the position of the head.
*/
if (etr_perf->snapshot)
handle->head += size;
/*
* Ensure that the AUX trace data is visible before the aux_head
* is updated via perf_aux_output_end(), as expected by the
* perf ring buffer.
*/
smp_wmb();
out:
/*
* Don't set the TRUNCATED flag in snapshot mode because 1) the
* captured buffer is expected to be truncated and 2) a full buffer
* prevents the event from being re-enabled by the perf core,
* resulting in stale data being send to user space.
*/
if (!etr_perf->snapshot && lost)
perf_aux_output_flag(handle, PERF_AUX_FLAG_TRUNCATED);
return size;
}
static int tmc_enable_etr_sink_perf(struct coresight_device *csdev, void *data)
{
int rc = 0;
pid_t pid;
unsigned long flags;
struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
struct perf_output_handle *handle = data;
struct etr_perf_buffer *etr_perf = etm_perf_sink_config(handle);
spin_lock_irqsave(&drvdata->spinlock, flags);
/* Don't use this sink if it is already claimed by sysFS */
if (drvdata->mode == CS_MODE_SYSFS) {
rc = -EBUSY;
goto unlock_out;
}
if (WARN_ON(!etr_perf || !etr_perf->etr_buf)) {
rc = -EINVAL;
goto unlock_out;
}
/* Get a handle on the pid of the process to monitor */
pid = etr_perf->pid;
/* Do not proceed if this device is associated with another session */
if (drvdata->pid != -1 && drvdata->pid != pid) {
rc = -EBUSY;
goto unlock_out;
}
/*
* No HW configuration is needed if the sink is already in
* use for this session.
*/
if (drvdata->pid == pid) {
atomic_inc(csdev->refcnt);
goto unlock_out;
}
rc = tmc_etr_enable_hw(drvdata, etr_perf->etr_buf);
if (!rc) {
/* Associate with monitored process. */
drvdata->pid = pid;
drvdata->mode = CS_MODE_PERF;
drvdata->perf_buf = etr_perf->etr_buf;
atomic_inc(csdev->refcnt);
}
unlock_out:
spin_unlock_irqrestore(&drvdata->spinlock, flags);
return rc;
}
static int tmc_enable_etr_sink(struct coresight_device *csdev,
u32 mode, void *data)
{
switch (mode) {
case CS_MODE_SYSFS:
return tmc_enable_etr_sink_sysfs(csdev);
case CS_MODE_PERF:
return tmc_enable_etr_sink_perf(csdev, data);
}
/* We shouldn't be here */
return -EINVAL;
}
static int tmc_disable_etr_sink(struct coresight_device *csdev)
{
unsigned long flags;
struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
spin_lock_irqsave(&drvdata->spinlock, flags);
if (drvdata->reading) {
spin_unlock_irqrestore(&drvdata->spinlock, flags);
return -EBUSY;
}
if (atomic_dec_return(csdev->refcnt)) {
spin_unlock_irqrestore(&drvdata->spinlock, flags);
return -EBUSY;
}
/* Complain if we (somehow) got out of sync */
WARN_ON_ONCE(drvdata->mode == CS_MODE_DISABLED);
tmc_etr_disable_hw(drvdata);
/* Dissociate from monitored process. */
drvdata->pid = -1;
drvdata->mode = CS_MODE_DISABLED;
/* Reset perf specific data */
drvdata->perf_buf = NULL;
spin_unlock_irqrestore(&drvdata->spinlock, flags);
dev_dbg(&csdev->dev, "TMC-ETR disabled\n");
return 0;
}
static const struct coresight_ops_sink tmc_etr_sink_ops = {
.enable = tmc_enable_etr_sink,
.disable = tmc_disable_etr_sink,
.alloc_buffer = tmc_alloc_etr_buffer,
.update_buffer = tmc_update_etr_buffer,
.free_buffer = tmc_free_etr_buffer,
};
const struct coresight_ops tmc_etr_cs_ops = {
.sink_ops = &tmc_etr_sink_ops,
};
int tmc_read_prepare_etr(struct tmc_drvdata *drvdata)
{
int ret = 0;
unsigned long flags;
/* config types are set a boot time and never change */
if (WARN_ON_ONCE(drvdata->config_type != TMC_CONFIG_TYPE_ETR))
return -EINVAL;
spin_lock_irqsave(&drvdata->spinlock, flags);
if (drvdata->reading) {
ret = -EBUSY;
goto out;
}
/*
* We can safely allow reads even if the ETR is operating in PERF mode,
* since the sysfs session is captured in mode specific data.
* If drvdata::sysfs_data is NULL the trace data has been read already.
*/
if (!drvdata->sysfs_buf) {
ret = -EINVAL;
goto out;
}
/* Disable the TMC if we are trying to read from a running session. */
if (drvdata->mode == CS_MODE_SYSFS)
__tmc_etr_disable_hw(drvdata);
drvdata->reading = true;
out:
spin_unlock_irqrestore(&drvdata->spinlock, flags);
return ret;
}
int tmc_read_unprepare_etr(struct tmc_drvdata *drvdata)
{
unsigned long flags;
struct etr_buf *sysfs_buf = NULL;
/* config types are set a boot time and never change */
if (WARN_ON_ONCE(drvdata->config_type != TMC_CONFIG_TYPE_ETR))
return -EINVAL;
spin_lock_irqsave(&drvdata->spinlock, flags);
/* RE-enable the TMC if need be */
if (drvdata->mode == CS_MODE_SYSFS) {
/*
* The trace run will continue with the same allocated trace
* buffer. Since the tracer is still enabled drvdata::buf can't
* be NULL.
*/
__tmc_etr_enable_hw(drvdata);
} else {
/*
* The ETR is not tracing and the buffer was just read.
* As such prepare to free the trace buffer.
*/
sysfs_buf = drvdata->sysfs_buf;
drvdata->sysfs_buf = NULL;
}
drvdata->reading = false;
spin_unlock_irqrestore(&drvdata->spinlock, flags);
/* Free allocated memory out side of the spinlock */
if (sysfs_buf)
tmc_etr_free_sysfs_buf(sysfs_buf);
return 0;
}