![Alistair Popple](/assets/img/avatar_default.png)
The PPC476GTR SoC supports message signalled interrupts (MSI) by writing to special addresses within the High Speed Transfer Assist (HSTA) module. This patch adds support for PCI MSI with a new system device. The DMA window is also updated to allow access to the entire 42-bit address range to allow PCI devices write access to the HSTA module. Signed-off-by: Alistair Popple <alistair@popple.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
216 lines
4.9 KiB
C
216 lines
4.9 KiB
C
/*
|
|
* MSI support for PPC4xx SoCs using High Speed Transfer Assist (HSTA) for
|
|
* generation of the interrupt.
|
|
*
|
|
* Copyright © 2013 Alistair Popple <alistair@popple.id.au> 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/kernel.h>
|
|
#include <linux/interrupt.h>
|
|
#include <linux/msi.h>
|
|
#include <linux/of.h>
|
|
#include <linux/of_platform.h>
|
|
#include <linux/pci.h>
|
|
#include <linux/semaphore.h>
|
|
#include <asm/msi_bitmap.h>
|
|
|
|
struct ppc4xx_hsta_msi {
|
|
struct device *dev;
|
|
|
|
/* The ioremapped HSTA MSI IO space */
|
|
u32 __iomem *data;
|
|
|
|
/* Physical address of HSTA MSI IO space */
|
|
u64 address;
|
|
struct msi_bitmap bmp;
|
|
|
|
/* An array mapping offsets to hardware IRQs */
|
|
int *irq_map;
|
|
|
|
/* Number of hwirqs supported */
|
|
int irq_count;
|
|
};
|
|
static struct ppc4xx_hsta_msi ppc4xx_hsta_msi;
|
|
|
|
static int hsta_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
|
|
{
|
|
struct msi_msg msg;
|
|
struct msi_desc *entry;
|
|
int irq, hwirq;
|
|
u64 addr;
|
|
|
|
list_for_each_entry(entry, &dev->msi_list, list) {
|
|
irq = msi_bitmap_alloc_hwirqs(&ppc4xx_hsta_msi.bmp, 1);
|
|
if (irq < 0) {
|
|
pr_debug("%s: Failed to allocate msi interrupt\n",
|
|
__func__);
|
|
return irq;
|
|
}
|
|
|
|
hwirq = ppc4xx_hsta_msi.irq_map[irq];
|
|
if (hwirq == NO_IRQ) {
|
|
pr_err("%s: Failed mapping irq %d\n", __func__, irq);
|
|
return -EINVAL;
|
|
}
|
|
|
|
/*
|
|
* HSTA generates interrupts on writes to 128-bit aligned
|
|
* addresses.
|
|
*/
|
|
addr = ppc4xx_hsta_msi.address + irq*0x10;
|
|
msg.address_hi = upper_32_bits(addr);
|
|
msg.address_lo = lower_32_bits(addr);
|
|
|
|
/* Data is not used by the HSTA. */
|
|
msg.data = 0;
|
|
|
|
pr_debug("%s: Setup irq %d (0x%0llx)\n", __func__, hwirq,
|
|
(((u64) msg.address_hi) << 32) | msg.address_lo);
|
|
|
|
if (irq_set_msi_desc(hwirq, entry)) {
|
|
pr_err(
|
|
"%s: Invalid hwirq %d specified in device tree\n",
|
|
__func__, hwirq);
|
|
msi_bitmap_free_hwirqs(&ppc4xx_hsta_msi.bmp, irq, 1);
|
|
return -EINVAL;
|
|
}
|
|
write_msi_msg(hwirq, &msg);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int hsta_find_hwirq_offset(int hwirq)
|
|
{
|
|
int irq;
|
|
|
|
/* Find the offset given the hwirq */
|
|
for (irq = 0; irq < ppc4xx_hsta_msi.irq_count; irq++)
|
|
if (ppc4xx_hsta_msi.irq_map[irq] == hwirq)
|
|
return irq;
|
|
|
|
return -EINVAL;
|
|
}
|
|
|
|
static void hsta_teardown_msi_irqs(struct pci_dev *dev)
|
|
{
|
|
struct msi_desc *entry;
|
|
int irq;
|
|
|
|
list_for_each_entry(entry, &dev->msi_list, list) {
|
|
if (entry->irq == NO_IRQ)
|
|
continue;
|
|
|
|
irq = hsta_find_hwirq_offset(entry->irq);
|
|
|
|
/* entry->irq should always be in irq_map */
|
|
BUG_ON(irq < 0);
|
|
irq_set_msi_desc(entry->irq, NULL);
|
|
msi_bitmap_free_hwirqs(&ppc4xx_hsta_msi.bmp, irq, 1);
|
|
pr_debug("%s: Teardown IRQ %u (index %u)\n", __func__,
|
|
entry->irq, irq);
|
|
}
|
|
}
|
|
|
|
static int hsta_msi_check_device(struct pci_dev *pdev, int nvec, int type)
|
|
{
|
|
/* We don't support MSI-X */
|
|
if (type == PCI_CAP_ID_MSIX) {
|
|
pr_debug("%s: MSI-X not supported.\n", __func__);
|
|
return -EINVAL;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int hsta_msi_probe(struct platform_device *pdev)
|
|
{
|
|
struct device *dev = &pdev->dev;
|
|
struct resource *mem;
|
|
int irq, ret, irq_count;
|
|
|
|
mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
|
|
if (IS_ERR(mem)) {
|
|
dev_err(dev, "Unable to get mmio space\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
irq_count = of_irq_count(dev->of_node);
|
|
if (!irq_count) {
|
|
dev_err(dev, "Unable to find IRQ range\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
ppc4xx_hsta_msi.dev = dev;
|
|
ppc4xx_hsta_msi.address = mem->start;
|
|
ppc4xx_hsta_msi.data = ioremap(mem->start, resource_size(mem));
|
|
ppc4xx_hsta_msi.irq_count = irq_count;
|
|
if (IS_ERR(ppc4xx_hsta_msi.data)) {
|
|
dev_err(dev, "Unable to map memory\n");
|
|
return -ENOMEM;
|
|
}
|
|
|
|
ret = msi_bitmap_alloc(&ppc4xx_hsta_msi.bmp, irq_count, dev->of_node);
|
|
if (ret)
|
|
goto out;
|
|
|
|
ppc4xx_hsta_msi.irq_map = kmalloc(sizeof(int) * irq_count, GFP_KERNEL);
|
|
if (IS_ERR(ppc4xx_hsta_msi.irq_map)) {
|
|
ret = -ENOMEM;
|
|
goto out1;
|
|
}
|
|
|
|
/* Setup a mapping from irq offsets to hardware irq numbers */
|
|
for (irq = 0; irq < irq_count; irq++) {
|
|
ppc4xx_hsta_msi.irq_map[irq] =
|
|
irq_of_parse_and_map(dev->of_node, irq);
|
|
if (ppc4xx_hsta_msi.irq_map[irq] == NO_IRQ) {
|
|
dev_err(dev, "Unable to map IRQ\n");
|
|
ret = -EINVAL;
|
|
goto out2;
|
|
}
|
|
}
|
|
|
|
ppc_md.setup_msi_irqs = hsta_setup_msi_irqs;
|
|
ppc_md.teardown_msi_irqs = hsta_teardown_msi_irqs;
|
|
ppc_md.msi_check_device = hsta_msi_check_device;
|
|
return 0;
|
|
|
|
out2:
|
|
kfree(ppc4xx_hsta_msi.irq_map);
|
|
|
|
out1:
|
|
msi_bitmap_free(&ppc4xx_hsta_msi.bmp);
|
|
|
|
out:
|
|
iounmap(ppc4xx_hsta_msi.data);
|
|
return ret;
|
|
}
|
|
|
|
static const struct of_device_id hsta_msi_ids[] = {
|
|
{
|
|
.compatible = "ibm,hsta-msi",
|
|
},
|
|
{}
|
|
};
|
|
|
|
static struct platform_driver hsta_msi_driver = {
|
|
.probe = hsta_msi_probe,
|
|
.driver = {
|
|
.name = "hsta-msi",
|
|
.owner = THIS_MODULE,
|
|
.of_match_table = hsta_msi_ids,
|
|
},
|
|
};
|
|
|
|
static int hsta_msi_init(void)
|
|
{
|
|
return platform_driver_register(&hsta_msi_driver);
|
|
}
|
|
subsys_initcall(hsta_msi_init);
|