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powerpc/powernv: Implement MSI support for p5ioc2 PCIe
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This implements support for MSIs on p5ioc2 PHBs. We only support
MSIs on the PCIe PHBs, not the PCI-X ones as the later hasn't been
properly verified in HW.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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Benjamin Herrenschmidt committed Sep 20, 2011
1 parent 61305a9 commit c1a2562
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49 changes: 49 additions & 0 deletions arch/powerpc/platforms/powernv/pci-p5ioc2.c
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Original file line number Diff line number Diff line change
Expand Up @@ -19,6 +19,7 @@
#include <linux/bootmem.h>
#include <linux/irq.h>
#include <linux/io.h>
#include <linux/msi.h>

#include <asm/sections.h>
#include <asm/io.h>
Expand All @@ -39,6 +40,51 @@
*/
#define P5IOC2_TCE_MEMORY 0x01000000

#ifdef CONFIG_PCI_MSI
static int pnv_pci_p5ioc2_msi_setup(struct pnv_phb *phb, struct pci_dev *dev,
unsigned int hwirq, unsigned int is_64,
struct msi_msg *msg)
{
if (WARN_ON(!is_64))
return -ENXIO;
msg->data = hwirq - phb->msi_base;
msg->address_hi = 0x10000000;
msg->address_lo = 0;

return 0;
}

static void pnv_pci_init_p5ioc2_msis(struct pnv_phb *phb)
{
unsigned int bmap_size;
const __be32 *prop = of_get_property(phb->hose->dn,
"ibm,opal-msi-ranges", NULL);
if (!prop)
return;

/* Don't do MSI's on p5ioc2 PCI-X are they are not properly
* verified in HW
*/
if (of_device_is_compatible(phb->hose->dn, "ibm,p5ioc2-pcix"))
return;
phb->msi_base = be32_to_cpup(prop);
phb->msi_count = be32_to_cpup(prop + 1);
bmap_size = BITS_TO_LONGS(phb->msi_count) * sizeof(unsigned long);
phb->msi_map = zalloc_maybe_bootmem(bmap_size, GFP_KERNEL);
if (!phb->msi_map) {
pr_err("PCI %d: Failed to allocate MSI bitmap !\n",
phb->hose->global_number);
return;
}
phb->msi_setup = pnv_pci_p5ioc2_msi_setup;
phb->msi32_support = 0;
pr_info(" Allocated bitmap for %d MSIs (base IRQ 0x%x)\n",
phb->msi_count, phb->msi_base);
}
#else
static void pnv_pci_init_p5ioc2_msis(struct pnv_phb *phb) { }
#endif /* CONFIG_PCI_MSI */

static void __devinit pnv_pci_p5ioc2_dma_dev_setup(struct pnv_phb *phb,
struct pci_dev *pdev)
{
Expand Down Expand Up @@ -117,6 +163,9 @@ static void __init pnv_pci_init_p5ioc2_phb(struct device_node *np,

phb->hose->ops = &pnv_pci_ops;

/* Setup MSI support */
pnv_pci_init_p5ioc2_msis(phb);

/* Setup TCEs */
phb->dma_dev_setup = pnv_pci_p5ioc2_dma_dev_setup;
pnv_pci_setup_iommu_table(&phb->p5ioc2.iommu_table,
Expand Down
109 changes: 109 additions & 0 deletions arch/powerpc/platforms/powernv/pci.c
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Original file line number Diff line number Diff line change
Expand Up @@ -19,6 +19,7 @@
#include <linux/bootmem.h>
#include <linux/irq.h>
#include <linux/io.h>
#include <linux/msi.h>

#include <asm/sections.h>
#include <asm/io.h>
Expand All @@ -38,6 +39,108 @@
#define cfg_dbg(fmt...) do { } while(0)
//#define cfg_dbg(fmt...) printk(fmt)

#ifdef CONFIG_PCI_MSI
static int pnv_msi_check_device(struct pci_dev* pdev, int nvec, int type)
{
struct pci_controller *hose = pci_bus_to_host(pdev->bus);
struct pnv_phb *phb = hose->private_data;

return (phb && phb->msi_map) ? 0 : -ENODEV;
}

static unsigned int pnv_get_one_msi(struct pnv_phb *phb)
{
unsigned int id;

spin_lock(&phb->lock);
id = find_next_zero_bit(phb->msi_map, phb->msi_count, phb->msi_next);
if (id >= phb->msi_count && phb->msi_next)
id = find_next_zero_bit(phb->msi_map, phb->msi_count, 0);
if (id >= phb->msi_count) {
spin_unlock(&phb->lock);
return 0;
}
__set_bit(id, phb->msi_map);
spin_unlock(&phb->lock);
return id + phb->msi_base;
}

static void pnv_put_msi(struct pnv_phb *phb, unsigned int hwirq)
{
unsigned int id;

if (WARN_ON(hwirq < phb->msi_base ||
hwirq >= (phb->msi_base + phb->msi_count)))
return;
id = hwirq - phb->msi_base;
spin_lock(&phb->lock);
__clear_bit(id, phb->msi_map);
spin_unlock(&phb->lock);
}

static int pnv_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)
{
struct pci_controller *hose = pci_bus_to_host(pdev->bus);
struct pnv_phb *phb = hose->private_data;
struct msi_desc *entry;
struct msi_msg msg;
unsigned int hwirq, virq;
int rc;

if (WARN_ON(!phb))
return -ENODEV;

list_for_each_entry(entry, &pdev->msi_list, list) {
if (!entry->msi_attrib.is_64 && !phb->msi32_support) {
pr_warn("%s: Supports only 64-bit MSIs\n",
pci_name(pdev));
return -ENXIO;
}
hwirq = pnv_get_one_msi(phb);
if (!hwirq) {
pr_warn("%s: Failed to find a free MSI\n",
pci_name(pdev));
return -ENOSPC;
}
virq = irq_create_mapping(NULL, hwirq);
if (virq == NO_IRQ) {
pr_warn("%s: Failed to map MSI to linux irq\n",
pci_name(pdev));
pnv_put_msi(phb, hwirq);
return -ENOMEM;
}
rc = phb->msi_setup(phb, pdev, hwirq, entry->msi_attrib.is_64,
&msg);
if (rc) {
pr_warn("%s: Failed to setup MSI\n", pci_name(pdev));
irq_dispose_mapping(virq);
pnv_put_msi(phb, hwirq);
return rc;
}
irq_set_msi_desc(virq, entry);
write_msi_msg(virq, &msg);
}
return 0;
}

static void pnv_teardown_msi_irqs(struct pci_dev *pdev)
{
struct pci_controller *hose = pci_bus_to_host(pdev->bus);
struct pnv_phb *phb = hose->private_data;
struct msi_desc *entry;

if (WARN_ON(!phb))
return;

list_for_each_entry(entry, &pdev->msi_list, list) {
if (entry->irq == NO_IRQ)
continue;
irq_set_msi_desc(entry->irq, NULL);
pnv_put_msi(phb, virq_to_hw(entry->irq));
irq_dispose_mapping(entry->irq);
}
}
#endif /* CONFIG_PCI_MSI */

static void pnv_pci_config_check_eeh(struct pnv_phb *phb, struct pci_bus *bus,
u32 bdfn)
Expand Down Expand Up @@ -283,4 +386,10 @@ void __init pnv_pci_init(void)
ppc_md.tce_free = pnv_tce_free;
set_pci_dma_ops(&dma_iommu_ops);

/* Configure MSIs */
#ifdef CONFIG_PCI_MSI
ppc_md.msi_check_device = pnv_msi_check_device;
ppc_md.setup_msi_irqs = pnv_setup_msi_irqs;
ppc_md.teardown_msi_irqs = pnv_teardown_msi_irqs;
#endif
}
10 changes: 10 additions & 0 deletions arch/powerpc/platforms/powernv/pci.h
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Original file line number Diff line number Diff line change
Expand Up @@ -16,6 +16,16 @@ struct pnv_phb {
void __iomem *regs;
spinlock_t lock;

#ifdef CONFIG_PCI_MSI
unsigned long *msi_map;
unsigned int msi_base;
unsigned int msi_count;
unsigned int msi_next;
unsigned int msi32_support;
#endif
int (*msi_setup)(struct pnv_phb *phb, struct pci_dev *dev,
unsigned int hwirq, unsigned int is_64,
struct msi_msg *msg);
void (*dma_dev_setup)(struct pnv_phb *phb, struct pci_dev *pdev);
void (*fixup_phb)(struct pci_controller *hose);
u32 (*bdfn_to_pe)(struct pnv_phb *phb, struct pci_bus *bus, u32 devfn);
Expand Down

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