482 lines
11 KiB
C
482 lines
11 KiB
C
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// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Copyright 2007, Michael Ellerman, IBM Corporation.
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*/
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#include <linux/interrupt.h>
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#include <linux/irq.h>
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#include <linux/kernel.h>
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#include <linux/pci.h>
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#include <linux/msi.h>
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#include <linux/export.h>
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#include <linux/of_platform.h>
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#include <linux/slab.h>
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#include <linux/debugfs.h>
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#include <linux/of_irq.h>
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#include <asm/dcr.h>
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#include <asm/machdep.h>
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#include "cell.h"
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/*
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* MSIC registers, specified as offsets from dcr_base
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*/
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#define MSIC_CTRL_REG 0x0
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/* Base Address registers specify FIFO location in BE memory */
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#define MSIC_BASE_ADDR_HI_REG 0x3
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#define MSIC_BASE_ADDR_LO_REG 0x4
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/* Hold the read/write offsets into the FIFO */
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#define MSIC_READ_OFFSET_REG 0x5
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#define MSIC_WRITE_OFFSET_REG 0x6
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/* MSIC control register flags */
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#define MSIC_CTRL_ENABLE 0x0001
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#define MSIC_CTRL_FIFO_FULL_ENABLE 0x0002
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#define MSIC_CTRL_IRQ_ENABLE 0x0008
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#define MSIC_CTRL_FULL_STOP_ENABLE 0x0010
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/*
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* The MSIC can be configured to use a FIFO of 32KB, 64KB, 128KB or 256KB.
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* Currently we're using a 64KB FIFO size.
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*/
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#define MSIC_FIFO_SIZE_SHIFT 16
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#define MSIC_FIFO_SIZE_BYTES (1 << MSIC_FIFO_SIZE_SHIFT)
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/*
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* To configure the FIFO size as (1 << n) bytes, we write (n - 15) into bits
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* 8-9 of the MSIC control reg.
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*/
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#define MSIC_CTRL_FIFO_SIZE (((MSIC_FIFO_SIZE_SHIFT - 15) << 8) & 0x300)
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/*
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* We need to mask the read/write offsets to make sure they stay within
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* the bounds of the FIFO. Also they should always be 16-byte aligned.
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*/
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#define MSIC_FIFO_SIZE_MASK ((MSIC_FIFO_SIZE_BYTES - 1) & ~0xFu)
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/* Each entry in the FIFO is 16 bytes, the first 4 bytes hold the irq # */
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#define MSIC_FIFO_ENTRY_SIZE 0x10
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struct axon_msic {
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struct irq_domain *irq_domain;
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__le32 *fifo_virt;
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dma_addr_t fifo_phys;
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dcr_host_t dcr_host;
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u32 read_offset;
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#ifdef DEBUG
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u32 __iomem *trigger;
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#endif
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};
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#ifdef DEBUG
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void axon_msi_debug_setup(struct device_node *dn, struct axon_msic *msic);
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#else
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static inline void axon_msi_debug_setup(struct device_node *dn,
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struct axon_msic *msic) { }
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#endif
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static void msic_dcr_write(struct axon_msic *msic, unsigned int dcr_n, u32 val)
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{
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pr_devel("axon_msi: dcr_write(0x%x, 0x%x)\n", val, dcr_n);
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dcr_write(msic->dcr_host, dcr_n, val);
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}
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static void axon_msi_cascade(struct irq_desc *desc)
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{
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struct irq_chip *chip = irq_desc_get_chip(desc);
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struct axon_msic *msic = irq_desc_get_handler_data(desc);
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u32 write_offset, msi;
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int idx;
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int retry = 0;
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write_offset = dcr_read(msic->dcr_host, MSIC_WRITE_OFFSET_REG);
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pr_devel("axon_msi: original write_offset 0x%x\n", write_offset);
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/* write_offset doesn't wrap properly, so we have to mask it */
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write_offset &= MSIC_FIFO_SIZE_MASK;
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while (msic->read_offset != write_offset && retry < 100) {
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idx = msic->read_offset / sizeof(__le32);
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msi = le32_to_cpu(msic->fifo_virt[idx]);
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msi &= 0xFFFF;
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pr_devel("axon_msi: woff %x roff %x msi %x\n",
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write_offset, msic->read_offset, msi);
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if (msi < nr_irqs && irq_get_chip_data(msi) == msic) {
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generic_handle_irq(msi);
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msic->fifo_virt[idx] = cpu_to_le32(0xffffffff);
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} else {
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/*
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* Reading the MSIC_WRITE_OFFSET_REG does not
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* reliably flush the outstanding DMA to the
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* FIFO buffer. Here we were reading stale
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* data, so we need to retry.
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*/
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udelay(1);
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retry++;
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pr_devel("axon_msi: invalid irq 0x%x!\n", msi);
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continue;
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}
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if (retry) {
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pr_devel("axon_msi: late irq 0x%x, retry %d\n",
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msi, retry);
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retry = 0;
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}
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msic->read_offset += MSIC_FIFO_ENTRY_SIZE;
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msic->read_offset &= MSIC_FIFO_SIZE_MASK;
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}
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if (retry) {
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printk(KERN_WARNING "axon_msi: irq timed out\n");
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msic->read_offset += MSIC_FIFO_ENTRY_SIZE;
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msic->read_offset &= MSIC_FIFO_SIZE_MASK;
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}
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chip->irq_eoi(&desc->irq_data);
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}
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static struct axon_msic *find_msi_translator(struct pci_dev *dev)
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{
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struct irq_domain *irq_domain;
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struct device_node *dn, *tmp;
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const phandle *ph;
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struct axon_msic *msic = NULL;
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dn = of_node_get(pci_device_to_OF_node(dev));
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if (!dn) {
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dev_dbg(&dev->dev, "axon_msi: no pci_dn found\n");
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return NULL;
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}
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for (; dn; dn = of_get_next_parent(dn)) {
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ph = of_get_property(dn, "msi-translator", NULL);
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if (ph)
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break;
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}
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if (!ph) {
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dev_dbg(&dev->dev,
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"axon_msi: no msi-translator property found\n");
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goto out_error;
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}
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tmp = dn;
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dn = of_find_node_by_phandle(*ph);
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of_node_put(tmp);
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if (!dn) {
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dev_dbg(&dev->dev,
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"axon_msi: msi-translator doesn't point to a node\n");
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goto out_error;
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}
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irq_domain = irq_find_host(dn);
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if (!irq_domain) {
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dev_dbg(&dev->dev, "axon_msi: no irq_domain found for node %pOF\n",
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dn);
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goto out_error;
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}
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msic = irq_domain->host_data;
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out_error:
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of_node_put(dn);
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return msic;
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}
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static int setup_msi_msg_address(struct pci_dev *dev, struct msi_msg *msg)
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{
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struct device_node *dn;
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int len;
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const u32 *prop;
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dn = of_node_get(pci_device_to_OF_node(dev));
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if (!dn) {
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dev_dbg(&dev->dev, "axon_msi: no pci_dn found\n");
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return -ENODEV;
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}
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for (; dn; dn = of_get_next_parent(dn)) {
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if (!dev->no_64bit_msi) {
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prop = of_get_property(dn, "msi-address-64", &len);
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if (prop)
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break;
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}
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prop = of_get_property(dn, "msi-address-32", &len);
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if (prop)
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break;
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}
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if (!prop) {
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dev_dbg(&dev->dev,
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"axon_msi: no msi-address-(32|64) properties found\n");
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of_node_put(dn);
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return -ENOENT;
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}
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switch (len) {
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case 8:
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msg->address_hi = prop[0];
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msg->address_lo = prop[1];
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break;
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case 4:
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msg->address_hi = 0;
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msg->address_lo = prop[0];
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break;
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default:
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dev_dbg(&dev->dev,
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"axon_msi: malformed msi-address-(32|64) property\n");
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of_node_put(dn);
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return -EINVAL;
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}
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of_node_put(dn);
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return 0;
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}
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static int axon_msi_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
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{
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unsigned int virq, rc;
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struct msi_desc *entry;
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struct msi_msg msg;
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struct axon_msic *msic;
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msic = find_msi_translator(dev);
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if (!msic)
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return -ENODEV;
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rc = setup_msi_msg_address(dev, &msg);
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if (rc)
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return rc;
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msi_for_each_desc(entry, &dev->dev, MSI_DESC_NOTASSOCIATED) {
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virq = irq_create_direct_mapping(msic->irq_domain);
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if (!virq) {
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dev_warn(&dev->dev,
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"axon_msi: virq allocation failed!\n");
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return -1;
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}
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dev_dbg(&dev->dev, "axon_msi: allocated virq 0x%x\n", virq);
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irq_set_msi_desc(virq, entry);
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msg.data = virq;
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pci_write_msi_msg(virq, &msg);
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}
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return 0;
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}
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static void axon_msi_teardown_msi_irqs(struct pci_dev *dev)
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{
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struct msi_desc *entry;
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dev_dbg(&dev->dev, "axon_msi: tearing down msi irqs\n");
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msi_for_each_desc(entry, &dev->dev, MSI_DESC_ASSOCIATED) {
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irq_set_msi_desc(entry->irq, NULL);
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irq_dispose_mapping(entry->irq);
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entry->irq = 0;
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}
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}
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static struct irq_chip msic_irq_chip = {
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.irq_mask = pci_msi_mask_irq,
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.irq_unmask = pci_msi_unmask_irq,
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.irq_shutdown = pci_msi_mask_irq,
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.name = "AXON-MSI",
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};
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static int msic_host_map(struct irq_domain *h, unsigned int virq,
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irq_hw_number_t hw)
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{
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irq_set_chip_data(virq, h->host_data);
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irq_set_chip_and_handler(virq, &msic_irq_chip, handle_simple_irq);
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return 0;
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}
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static const struct irq_domain_ops msic_host_ops = {
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.map = msic_host_map,
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};
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static void axon_msi_shutdown(struct platform_device *device)
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{
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struct axon_msic *msic = dev_get_drvdata(&device->dev);
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u32 tmp;
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pr_devel("axon_msi: disabling %pOF\n",
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irq_domain_get_of_node(msic->irq_domain));
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tmp = dcr_read(msic->dcr_host, MSIC_CTRL_REG);
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tmp &= ~MSIC_CTRL_ENABLE & ~MSIC_CTRL_IRQ_ENABLE;
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msic_dcr_write(msic, MSIC_CTRL_REG, tmp);
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}
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static int axon_msi_probe(struct platform_device *device)
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{
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struct device_node *dn = device->dev.of_node;
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struct axon_msic *msic;
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unsigned int virq;
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int dcr_base, dcr_len;
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pr_devel("axon_msi: setting up dn %pOF\n", dn);
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msic = kzalloc(sizeof(*msic), GFP_KERNEL);
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if (!msic) {
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printk(KERN_ERR "axon_msi: couldn't allocate msic for %pOF\n",
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dn);
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goto out;
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}
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dcr_base = dcr_resource_start(dn, 0);
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dcr_len = dcr_resource_len(dn, 0);
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if (dcr_base == 0 || dcr_len == 0) {
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printk(KERN_ERR
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"axon_msi: couldn't parse dcr properties on %pOF\n",
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dn);
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goto out_free_msic;
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}
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msic->dcr_host = dcr_map(dn, dcr_base, dcr_len);
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if (!DCR_MAP_OK(msic->dcr_host)) {
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printk(KERN_ERR "axon_msi: dcr_map failed for %pOF\n",
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dn);
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goto out_free_msic;
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}
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msic->fifo_virt = dma_alloc_coherent(&device->dev, MSIC_FIFO_SIZE_BYTES,
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&msic->fifo_phys, GFP_KERNEL);
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if (!msic->fifo_virt) {
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printk(KERN_ERR "axon_msi: couldn't allocate fifo for %pOF\n",
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dn);
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goto out_free_msic;
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}
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virq = irq_of_parse_and_map(dn, 0);
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if (!virq) {
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printk(KERN_ERR "axon_msi: irq parse and map failed for %pOF\n",
|
||
|
|
dn);
|
||
|
|
goto out_free_fifo;
|
||
|
|
}
|
||
|
|
memset(msic->fifo_virt, 0xff, MSIC_FIFO_SIZE_BYTES);
|
||
|
|
|
||
|
|
/* We rely on being able to stash a virq in a u16, so limit irqs to < 65536 */
|
||
|
|
msic->irq_domain = irq_domain_add_nomap(dn, 65536, &msic_host_ops, msic);
|
||
|
|
if (!msic->irq_domain) {
|
||
|
|
printk(KERN_ERR "axon_msi: couldn't allocate irq_domain for %pOF\n",
|
||
|
|
dn);
|
||
|
|
goto out_free_fifo;
|
||
|
|
}
|
||
|
|
|
||
|
|
irq_set_handler_data(virq, msic);
|
||
|
|
irq_set_chained_handler(virq, axon_msi_cascade);
|
||
|
|
pr_devel("axon_msi: irq 0x%x setup for axon_msi\n", virq);
|
||
|
|
|
||
|
|
/* Enable the MSIC hardware */
|
||
|
|
msic_dcr_write(msic, MSIC_BASE_ADDR_HI_REG, msic->fifo_phys >> 32);
|
||
|
|
msic_dcr_write(msic, MSIC_BASE_ADDR_LO_REG,
|
||
|
|
msic->fifo_phys & 0xFFFFFFFF);
|
||
|
|
msic_dcr_write(msic, MSIC_CTRL_REG,
|
||
|
|
MSIC_CTRL_IRQ_ENABLE | MSIC_CTRL_ENABLE |
|
||
|
|
MSIC_CTRL_FIFO_SIZE);
|
||
|
|
|
||
|
|
msic->read_offset = dcr_read(msic->dcr_host, MSIC_WRITE_OFFSET_REG)
|
||
|
|
& MSIC_FIFO_SIZE_MASK;
|
||
|
|
|
||
|
|
dev_set_drvdata(&device->dev, msic);
|
||
|
|
|
||
|
|
cell_pci_controller_ops.setup_msi_irqs = axon_msi_setup_msi_irqs;
|
||
|
|
cell_pci_controller_ops.teardown_msi_irqs = axon_msi_teardown_msi_irqs;
|
||
|
|
|
||
|
|
axon_msi_debug_setup(dn, msic);
|
||
|
|
|
||
|
|
printk(KERN_DEBUG "axon_msi: setup MSIC on %pOF\n", dn);
|
||
|
|
|
||
|
|
return 0;
|
||
|
|
|
||
|
|
out_free_fifo:
|
||
|
|
dma_free_coherent(&device->dev, MSIC_FIFO_SIZE_BYTES, msic->fifo_virt,
|
||
|
|
msic->fifo_phys);
|
||
|
|
out_free_msic:
|
||
|
|
kfree(msic);
|
||
|
|
out:
|
||
|
|
|
||
|
|
return -1;
|
||
|
|
}
|
||
|
|
|
||
|
|
static const struct of_device_id axon_msi_device_id[] = {
|
||
|
|
{
|
||
|
|
.compatible = "ibm,axon-msic"
|
||
|
|
},
|
||
|
|
{}
|
||
|
|
};
|
||
|
|
|
||
|
|
static struct platform_driver axon_msi_driver = {
|
||
|
|
.probe = axon_msi_probe,
|
||
|
|
.shutdown = axon_msi_shutdown,
|
||
|
|
.driver = {
|
||
|
|
.name = "axon-msi",
|
||
|
|
.of_match_table = axon_msi_device_id,
|
||
|
|
},
|
||
|
|
};
|
||
|
|
|
||
|
|
static int __init axon_msi_init(void)
|
||
|
|
{
|
||
|
|
return platform_driver_register(&axon_msi_driver);
|
||
|
|
}
|
||
|
|
subsys_initcall(axon_msi_init);
|
||
|
|
|
||
|
|
|
||
|
|
#ifdef DEBUG
|
||
|
|
static int msic_set(void *data, u64 val)
|
||
|
|
{
|
||
|
|
struct axon_msic *msic = data;
|
||
|
|
out_le32(msic->trigger, val);
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
static int msic_get(void *data, u64 *val)
|
||
|
|
{
|
||
|
|
*val = 0;
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
DEFINE_SIMPLE_ATTRIBUTE(fops_msic, msic_get, msic_set, "%llu\n");
|
||
|
|
|
||
|
|
void axon_msi_debug_setup(struct device_node *dn, struct axon_msic *msic)
|
||
|
|
{
|
||
|
|
char name[8];
|
||
|
|
u64 addr;
|
||
|
|
|
||
|
|
addr = of_translate_address(dn, of_get_property(dn, "reg", NULL));
|
||
|
|
if (addr == OF_BAD_ADDR) {
|
||
|
|
pr_devel("axon_msi: couldn't translate reg property\n");
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
|
||
|
|
msic->trigger = ioremap(addr, 0x4);
|
||
|
|
if (!msic->trigger) {
|
||
|
|
pr_devel("axon_msi: ioremap failed\n");
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
|
||
|
|
snprintf(name, sizeof(name), "msic_%d", of_node_to_nid(dn));
|
||
|
|
|
||
|
|
debugfs_create_file(name, 0600, arch_debugfs_dir, msic, &fops_msic);
|
||
|
|
}
|
||
|
|
#endif /* DEBUG */
|