- 根目录:
- arch
- powerpc
- platforms
- cell
- axon_msi.c
/*
* Copyright 2007, Michael Ellerman, IBM Corporation.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/msi.h>
#include <linux/export.h>
#include <linux/of_platform.h>
#include <linux/debugfs.h>
#include <linux/slab.h>
#include <asm/dcr.h>
#include <asm/machdep.h>
#include <asm/prom.h>
/*
* MSIC registers, specified as offsets from dcr_base
*/
#define MSIC_CTRL_REG 0x0
/* Base Address registers specify FIFO location in BE memory */
#define MSIC_BASE_ADDR_HI_REG 0x3
#define MSIC_BASE_ADDR_LO_REG 0x4
/* Hold the read/write offsets into the FIFO */
#define MSIC_READ_OFFSET_REG 0x5
#define MSIC_WRITE_OFFSET_REG 0x6
/* MSIC control register flags */
#define MSIC_CTRL_ENABLE 0x0001
#define MSIC_CTRL_FIFO_FULL_ENABLE 0x0002
#define MSIC_CTRL_IRQ_ENABLE 0x0008
#define MSIC_CTRL_FULL_STOP_ENABLE 0x0010
/*
* The MSIC can be configured to use a FIFO of 32KB, 64KB, 128KB or 256KB.
* Currently we're using a 64KB FIFO size.
*/
#define MSIC_FIFO_SIZE_SHIFT 16
#define MSIC_FIFO_SIZE_BYTES (1 << MSIC_FIFO_SIZE_SHIFT)
/*
* To configure the FIFO size as (1 << n) bytes, we write (n - 15) into bits
* 8-9 of the MSIC control reg.
*/
#define MSIC_CTRL_FIFO_SIZE (((MSIC_FIFO_SIZE_SHIFT - 15) << 8) & 0x300)
/*
* We need to mask the read/write offsets to make sure they stay within
* the bounds of the FIFO. Also they should always be 16-byte aligned.
*/
#define MSIC_FIFO_SIZE_MASK ((MSIC_FIFO_SIZE_BYTES - 1) & ~0xFu)
/* Each entry in the FIFO is 16 bytes, the first 4 bytes hold the irq # */
#define MSIC_FIFO_ENTRY_SIZE 0x10
struct axon_msic {
struct irq_domain *irq_domain;
__le32 *fifo_virt;
dma_addr_t fifo_phys;
dcr_host_t dcr_host;
u32 read_offset;
#ifdef DEBUG
u32 __iomem *trigger;
#endif
};
#ifdef DEBUG
void axon_msi_debug_setup(struct device_node *dn, struct axon_msic *msic);
#else
static inline void axon_msi_debug_setup(struct device_node *dn,
struct axon_msic *msic) { }
#endif
static void msic_dcr_write(struct axon_msic *msic, unsigned int dcr_n, u32 val)
{
pr_devel("axon_msi: dcr_write(0x%x, 0x%x)\n", val, dcr_n);
dcr_write(msic->dcr_host, dcr_n, val);
}
static void axon_msi_cascade(unsigned int irq, struct irq_desc *desc)
{
struct irq_chip *chip = irq_desc_get_chip(desc);
struct axon_msic *msic = irq_get_handler_data(irq);
u32 write_offset, msi;
int idx;
int retry = 0;
write_offset = dcr_read(msic->dcr_host, MSIC_WRITE_OFFSET_REG);
pr_devel("axon_msi: original write_offset 0x%x\n", write_offset);
/* write_offset doesn't wrap properly, so we have to mask it */
write_offset &= MSIC_FIFO_SIZE_MASK;
while (msic->read_offset != write_offset && retry < 100) {
idx = msic->read_offset / sizeof(__le32);
msi = le32_to_cpu(msic->fifo_virt[idx]);
msi &= 0xFFFF;
pr_devel("axon_msi: woff %x roff %x msi %x\n",
write_offset, msic->read_offset, msi);
if (msi < nr_irqs && irq_get_chip_data(msi) == msic) {
generic_handle_irq(msi);
msic->fifo_virt[idx] = cpu_to_le32(0xffffffff);
} else {
/*
* Reading the MSIC_WRITE_OFFSET_REG does not
* reliably flush the outstanding DMA to the
* FIFO buffer. Here we were reading stale
* data, so we need to retry.
*/
udelay(1);
retry++;
pr_devel("axon_msi: invalid irq 0x%x!\n", msi);
continue;
}
if (retry) {
pr_devel("axon_msi: late irq 0x%x, retry %d\n",
msi, retry);
retry = 0;
}
msic->read_offset += MSIC_FIFO_ENTRY_SIZE;
msic->read_offset &= MSIC_FIFO_SIZE_MASK;
}
if (retry) {
printk(KERN_WARNING "axon_msi: irq timed out\n");
msic->read_offset += MSIC_FIFO_ENTRY_SIZE;
msic->read_offset &= MSIC_FIFO_SIZE_MASK;
}
chip->irq_eoi(&desc->irq_data);
}
static struct axon_msic *find_msi_translator(struct pci_dev *dev)
{
struct irq_domain *irq_domain;
struct device_node *dn, *tmp;
const phandle *ph;
struct axon_msic *msic = NULL;
dn = of_node_get(pci_device_to_OF_node(dev));
if (!dn) {
dev_dbg(&dev->dev, "axon_msi: no pci_dn found\n");
return NULL;
}
for (; dn; dn = of_get_next_parent(dn)) {
ph = of_get_property(dn, "msi-translator", NULL);
if (ph)
break;
}
if (!ph) {
dev_dbg(&dev->dev,
"axon_msi: no msi-translator property found\n");
goto out_error;
}
tmp = dn;
dn = of_find_node_by_phandle(*ph);
of_node_put(tmp);
if (!dn) {
dev_dbg(&dev->dev,
"axon_msi: msi-translator doesn't point to a node\n");
goto out_error;
}
irq_domain = irq_find_host(dn);
if (!irq_domain) {
dev_dbg(&dev->dev, "axon_msi: no irq_domain found for node %s\n",
dn->full_name);
goto out_error;
}
msic = irq_domain->host_data;
out_error:
of_node_put(dn);
return msic;
}
static int axon_msi_check_device(struct pci_dev *dev, int nvec, int type)
{
if (!find_msi_translator(dev))
return -ENODEV;
return 0;
}
static int setup_msi_msg_address(struct pci_dev *dev, struct msi_msg *msg)
{
struct device_node *dn;
struct msi_desc *entry;
int len;
const u32 *prop;
dn = of_node_get(pci_device_to_OF_node(dev));
if (!dn) {
dev_dbg(&dev->dev, "axon_msi: no pci_dn found\n");
return -ENODEV;
}
entry = list_first_entry(&dev->msi_list, struct msi_desc, list);
for (; dn; dn = of_get_next_parent(dn)) {
if (entry->msi_attrib.is_64) {
prop = of_get_property(dn, "msi-address-64", &len);
if (prop)
break;
}
prop = of_get_property(dn, "msi-address-32", &len);
if (prop)
break;
}
if (!prop) {
dev_dbg(&dev->dev,
"axon_msi: no msi-address-(32|64) properties found\n");
return -ENOENT;
}
switch (len) {
case 8:
msg->address_hi = prop[0];
msg->address_lo = prop[1];
break;
case 4:
msg->address_hi = 0;
msg->address_lo = prop[0];
break;
default:
dev_dbg(&dev->dev,
"axon_msi: malformed msi-address-(32|64) property\n");
of_node_put(dn);
return -EINVAL;
}
of_node_put(dn);
return 0;
}
static int axon_msi_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
{
unsigned int virq, rc;
struct msi_desc *entry;
struct msi_msg msg;
struct axon_msic *msic;
msic = find_msi_translator(dev);
if (!msic)
return -ENODEV;
rc = setup_msi_msg_address(dev, &msg);
if (rc)
return rc;
list_for_each_entry(entry, &dev->msi_list, list) {
virq = irq_create_direct_mapping(msic->irq_domain);
if (virq == NO_IRQ) {
dev_warn(&dev->dev,
"axon_msi: virq allocation failed!\n");
return -1;
}
dev_dbg(&dev->dev, "axon_msi: allocated virq 0x%x\n", virq);
irq_set_msi_desc(virq, entry);
msg.data = virq;
write_msi_msg(virq, &msg);
}
return 0;
}
static void axon_msi_teardown_msi_irqs(struct pci_dev *dev)
{
struct msi_desc *entry;
dev_dbg(&dev->dev, "axon_msi: tearing down msi irqs\n");
list_for_each_entry(entry, &dev->msi_list, list) {
if (entry->irq == NO_IRQ)
continue;
irq_set_msi_desc(entry->irq, NULL);
irq_dispose_mapping(entry->irq);
}
}
static struct irq_chip msic_irq_chip = {
.irq_mask = mask_msi_irq,
.irq_unmask = unmask_msi_irq,
.irq_shutdown = mask_msi_irq,
.name = "AXON-MSI",
};
static int msic_host_map(struct irq_domain *h, unsigned int virq,
irq_hw_number_t hw)
{
irq_set_chip_data(virq, h->host_data);
irq_set_chip_and_handler(virq, &msic_irq_chip, handle_simple_irq);
return 0;
}
static const struct irq_domain_ops msic_host_ops = {
.map = msic_host_map,
};
static void axon_msi_shutdown(struct platform_device *device)
{
struct axon_msic *msic = dev_get_drvdata(&device->dev);
u32 tmp;
pr_devel("axon_msi: disabling %s\n",
msic->irq_domain->of_node->full_name);
tmp = dcr_read(msic->dcr_host, MSIC_CTRL_REG);
tmp &= ~MSIC_CTRL_ENABLE & ~MSIC_CTRL_IRQ_ENABLE;
msic_dcr_write(msic, MSIC_CTRL_REG, tmp);
}
static int axon_msi_probe(struct platform_device *device)
{
struct device_node *dn = device->dev.of_node;
struct axon_msic *msic;
unsigned int virq;
int dcr_base, dcr_len;
pr_devel("axon_msi: setting up dn %s\n", dn->full_name);
msic = kzalloc(sizeof(struct axon_msic), GFP_KERNEL);
if (!msic) {
printk(KERN_ERR "axon_msi: couldn't allocate msic for %s\n",
dn->full_name);
goto out;
}
dcr_base = dcr_resource_start(dn, 0);
dcr_len = dcr_resource_len(dn, 0);
if (dcr_base == 0 || dcr_len == 0) {
printk(KERN_ERR
"axon_msi: couldn't parse dcr properties on %s\n",
dn->full_name);
goto out_free_msic;
}
msic->dcr_host = dcr_map(dn, dcr_base, dcr_len);
if (!DCR_MAP_OK(msic->dcr_host)) {
printk(KERN_ERR "axon_msi: dcr_map failed for %s\n",
dn->full_name);
goto out_free_msic;
}
msic->fifo_virt = dma_alloc_coherent(&device->dev, MSIC_FIFO_SIZE_BYTES,
&msic->fifo_phys, GFP_KERNEL);
if (!msic->fifo_virt) {
printk(KERN_ERR "axon_msi: couldn't allocate fifo for %s\n",
dn->full_name);
goto out_free_msic;
}
virq = irq_of_parse_and_map(dn, 0);
if (virq == NO_IRQ) {
printk(KERN_ERR "axon_msi: irq parse and map failed for %s\n",
dn->full_name);
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 %s\n",
dn->full_name);
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);
ppc_md.setup_msi_irqs = axon_msi_setup_msi_irqs;
ppc_md.teardown_msi_irqs = axon_msi_teardown_msi_irqs;
ppc_md.msi_check_device = axon_msi_check_device;
axon_msi_debug_setup(dn, msic);
printk(KERN_DEBUG "axon_msi: setup MSIC on %s\n", dn->full_name);
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",
.owner = THIS_MODULE,
.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));
if (!debugfs_create_file(name, 0600, powerpc_debugfs_root,
msic, &fops_msic)) {
pr_devel("axon_msi: debugfs_create_file failed!\n");
return;
}
}
#endif /* DEBUG */