powerpc/powernv: Use MSI bitmap to manage IRQs

As Michael Ellerman mentioned, arch/powerpc/sysdev/msi_bitmap.c
already implemented bitmap to manage (alloc/free) MSI interrupts.
The patch intends to use that mechanism to manage MSI interrupts
for PowerNV platform.

Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>

4 files changed, 25 insertions, 61 deletions

diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
index 8e90e8906df3..a5c5f15242ba 100644
--- a/arch/powerpc/platforms/powernv/pci-ioda.c
+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
@@ -26,6 +26,7 @@
 #include <asm/prom.h>
 #include <asm/pci-bridge.h>
 #include <asm/machdep.h>
+#include <asm/msi_bitmap.h>
 #include <asm/ppc-pci.h>
 #include <asm/opal.h>
 #include <asm/iommu.h>
@@ -647,7 +648,7 @@ static int pnv_pci_ioda_msi_setup(struct pnv_phb *phb, struct pci_dev *dev,
 
 static void pnv_pci_init_ioda_msis(struct pnv_phb *phb)
 {
-        unsigned int bmap_size;
+        unsigned int count;
         const __be32 *prop = of_get_property(phb->hose->dn,
                                              "ibm,opal-msi-ranges", NULL);
         if (!prop) {
@@ -658,18 +659,17 @@ static void pnv_pci_init_ioda_msis(struct pnv_phb *phb)
                 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) {
+        count = be32_to_cpup(prop + 1);
+        if (msi_bitmap_alloc(&phb->msi_bmp, count, phb->hose->dn)) {
                 pr_err("PCI %d: Failed to allocate MSI bitmap !\n",
                        phb->hose->global_number);
                 return;
         }
+
         phb->msi_setup = pnv_pci_ioda_msi_setup;
         phb->msi32_support = 1;
         pr_info("  Allocated bitmap for %d MSIs (base IRQ 0x%x)\n",
-                phb->msi_count, phb->msi_base);
+                count, phb->msi_base);
 }
 #else
 static void pnv_pci_init_ioda_msis(struct pnv_phb *phb) { }
diff --git a/arch/powerpc/platforms/powernv/pci-p5ioc2.c b/arch/powerpc/platforms/powernv/pci-p5ioc2.c
index 7db8771a40f5..d5c066ea7d1f 100644
--- a/arch/powerpc/platforms/powernv/pci-p5ioc2.c
+++ b/arch/powerpc/platforms/powernv/pci-p5ioc2.c
@@ -26,6 +26,7 @@
 #include <asm/prom.h>
 #include <asm/pci-bridge.h>
 #include <asm/machdep.h>
+#include <asm/msi_bitmap.h>
 #include <asm/ppc-pci.h>
 #include <asm/opal.h>
 #include <asm/iommu.h>
@@ -55,7 +56,7 @@ static int pnv_pci_p5ioc2_msi_setup(struct pnv_phb *phb, struct pci_dev *dev,
 
 static void pnv_pci_init_p5ioc2_msis(struct pnv_phb *phb)
 {
-        unsigned int bmap_size;
+        unsigned int count;
         const __be32 *prop = of_get_property(phb->hose->dn,
                                              "ibm,opal-msi-ranges", NULL);
         if (!prop)
@@ -67,10 +68,8 @@ static void pnv_pci_init_p5ioc2_msis(struct pnv_phb *phb)
         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) {
+        count = be32_to_cpup(prop + 1);
+        if (msi_bitmap_alloc(&phb->msi_bmp, count, phb->hose->dn)) {
                 pr_err("PCI %d: Failed to allocate MSI bitmap !\n",
                        phb->hose->global_number);
                 return;
@@ -78,7 +77,7 @@ static void pnv_pci_init_p5ioc2_msis(struct pnv_phb *phb)
         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);
+                count, phb->msi_base);
 }
 #else
 static void pnv_pci_init_p5ioc2_msis(struct pnv_phb *phb) { }
diff --git a/arch/powerpc/platforms/powernv/pci.c b/arch/powerpc/platforms/powernv/pci.c
index b8b8e0bd9897..42eee93ca9c3 100644
--- a/arch/powerpc/platforms/powernv/pci.c
+++ b/arch/powerpc/platforms/powernv/pci.c
@@ -26,6 +26,7 @@
 #include <asm/prom.h>
 #include <asm/pci-bridge.h>
 #include <asm/machdep.h>
+#include <asm/msi_bitmap.h>
 #include <asm/ppc-pci.h>
 #include <asm/opal.h>
 #include <asm/iommu.h>
@@ -47,43 +48,7 @@ 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 long flags;
-        unsigned int id, rc;
-
-        spin_lock_irqsave(&phb->lock, flags);
-
-        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) {
-                rc = 0;
-                goto out;
-        }
-        __set_bit(id, phb->msi_map);
-        rc = id + phb->msi_base;
-out:
-        spin_unlock_irqrestore(&phb->lock, flags);
-        return rc;
-}
-
-static void pnv_put_msi(struct pnv_phb *phb, unsigned int hwirq)
-{
-        unsigned long flags;
-        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_irqsave(&phb->lock, flags);
-        __clear_bit(id, phb->msi_map);
-        spin_unlock_irqrestore(&phb->lock, flags);
+        return (phb && phb->msi_bmp.bitmap) ? 0 : -ENODEV;
 }
 
 static int pnv_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)
@@ -92,7 +57,8 @@ static int pnv_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)
         struct pnv_phb *phb = hose->private_data;
         struct msi_desc *entry;
         struct msi_msg msg;
-        unsigned int hwirq, virq;
+        int hwirq;
+        unsigned int virq;
         int rc;
 
         if (WARN_ON(!phb))
@@ -104,25 +70,25 @@ static int pnv_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)
                                 pci_name(pdev));
                         return -ENXIO;
                 }
-                hwirq = pnv_get_one_msi(phb);
-                if (!hwirq) {
+                hwirq = msi_bitmap_alloc_hwirqs(&phb->msi_bmp, 1);
+                if (hwirq < 0) {
                         pr_warn("%s: Failed to find a free MSI\n",
                                 pci_name(pdev));
                         return -ENOSPC;
                 }
-                virq = irq_create_mapping(NULL, hwirq);
+                virq = irq_create_mapping(NULL, phb->msi_base + hwirq);
                 if (virq == NO_IRQ) {
                         pr_warn("%s: Failed to map MSI to linux irq\n",
                                 pci_name(pdev));
-                        pnv_put_msi(phb, hwirq);
+                        msi_bitmap_free_hwirqs(&phb->msi_bmp, hwirq, 1);
                         return -ENOMEM;
                 }
-                rc = phb->msi_setup(phb, pdev, hwirq, entry->msi_attrib.is_64,
-                                    &msg);
+                rc = phb->msi_setup(phb, pdev, phb->msi_base + 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);
+                        msi_bitmap_free_hwirqs(&phb->msi_bmp, hwirq, 1);
                         return rc;
                 }
                 irq_set_msi_desc(virq, entry);
@@ -144,7 +110,8 @@ static void pnv_teardown_msi_irqs(struct pci_dev *pdev)
                 if (entry->irq == NO_IRQ)
                         continue;
                 irq_set_msi_desc(entry->irq, NULL);
-                pnv_put_msi(phb, virq_to_hw(entry->irq));
+                msi_bitmap_free_hwirqs(&phb->msi_bmp,
+                        virq_to_hw(entry->irq) - phb->msi_base, 1);
                 irq_dispose_mapping(entry->irq);
         }
 }
diff --git a/arch/powerpc/platforms/powernv/pci.h b/arch/powerpc/platforms/powernv/pci.h
index 7cfb7c883deb..42ddfba79651 100644
--- a/arch/powerpc/platforms/powernv/pci.h
+++ b/arch/powerpc/platforms/powernv/pci.h
@@ -73,11 +73,9 @@ struct pnv_phb {
         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;
+        struct msi_bitmap       msi_bmp;
 #endif
         int (*msi_setup)(struct pnv_phb *phb, struct pci_dev *dev,
                          unsigned int hwirq, unsigned int is_64,