9 files changed, 315 insertions, 227 deletions

diff --git a/arch/powerpc/sysdev/Kconfig b/arch/powerpc/sysdev/Kconfig
index 72fb35b9ebca..396582835cb5 100644
--- a/arch/powerpc/sysdev/Kconfig
+++ b/arch/powerpc/sysdev/Kconfig
@@ -6,3 +6,9 @@ config PPC4xx_PCI_EXPRESS
 	bool
 	depends on PCI && 4xx
 	default n
+
+config PPC_MSI_BITMAP
+	bool
+	depends on PCI_MSI
+	default y if MPIC
+	default y if FSL_PCI
diff --git a/arch/powerpc/sysdev/Makefile b/arch/powerpc/sysdev/Makefile
index a90054b56d5c..b6c269eb2650 100644
--- a/arch/powerpc/sysdev/Makefile
+++ b/arch/powerpc/sysdev/Makefile
@@ -5,6 +5,7 @@ endif
 mpic-msi-obj-$(CONFIG_PCI_MSI)	+= mpic_msi.o mpic_u3msi.o mpic_pasemi_msi.o
 obj-$(CONFIG_MPIC)		+= mpic.o $(mpic-msi-obj-y)
 fsl-msi-obj-$(CONFIG_PCI_MSI)	+= fsl_msi.o
+obj-$(CONFIG_PPC_MSI_BITMAP)	+= msi_bitmap.o
 
 obj-$(CONFIG_PPC_MPC106)	+= grackle.o
 obj-$(CONFIG_PPC_DCR_NATIVE)	+= dcr-low.o
diff --git a/arch/powerpc/sysdev/fsl_msi.c b/arch/powerpc/sysdev/fsl_msi.c
index 2c5187cc8a24..f25ce818d40a 100644
--- a/arch/powerpc/sysdev/fsl_msi.c
+++ b/arch/powerpc/sysdev/fsl_msi.c
@@ -14,7 +14,6 @@
  */
 #include <linux/irq.h>
 #include <linux/bootmem.h>
-#include <linux/bitmap.h>
 #include <linux/msi.h>
 #include <linux/pci.h>
 #include <linux/of_platform.h>
@@ -67,95 +66,22 @@ static struct irq_host_ops fsl_msi_host_ops = {
 	.map = fsl_msi_host_map,
 };
 
-static irq_hw_number_t fsl_msi_alloc_hwirqs(struct fsl_msi *msi, int num)
-{
-	unsigned long flags;
-	int order = get_count_order(num);
-	int offset;
-
-	spin_lock_irqsave(&msi->bitmap_lock, flags);
-
-	offset = bitmap_find_free_region(msi->fsl_msi_bitmap,
-					NR_MSI_IRQS, order);
-
-	spin_unlock_irqrestore(&msi->bitmap_lock, flags);
-
-	pr_debug("%s: allocated 0x%x (2^%d) at offset 0x%x\n",
-		__func__, num, order, offset);
-
-	return offset;
-}
-
-static void fsl_msi_free_hwirqs(struct fsl_msi *msi, int offset, int num)
-{
-	unsigned long flags;
-	int order = get_count_order(num);
-
-	pr_debug("%s: freeing 0x%x (2^%d) at offset 0x%x\n",
-		__func__, num, order, offset);
-
-	spin_lock_irqsave(&msi->bitmap_lock, flags);
-	bitmap_release_region(msi->fsl_msi_bitmap, offset, order);
-	spin_unlock_irqrestore(&msi->bitmap_lock, flags);
-}
-
-static int fsl_msi_free_dt_hwirqs(struct fsl_msi *msi)
-{
-	int i;
-	int len;
-	const u32 *p;
-
-	bitmap_allocate_region(msi->fsl_msi_bitmap, 0,
-		       get_count_order(NR_MSI_IRQS));
-
-	p = of_get_property(msi->of_node, "msi-available-ranges", &len);
-
-	if (!p) {
-		/* No msi-available-ranges property,
-		 * All the 256 MSI interrupts can be used
-		 */
-		fsl_msi_free_hwirqs(msi, 0, 0x100);
-		return 0;
-	}
-
-	if ((len % (2 * sizeof(u32))) != 0) {
-		printk(KERN_WARNING "fsl_msi: Malformed msi-available-ranges "
-		       "property on %s\n", msi->of_node->full_name);
-		return -EINVAL;
-	}
-
-	/* Format is: (<u32 start> <u32 count>)+ */
-	len /= 2 * sizeof(u32);
-	for (i = 0; i < len; i++, p += 2)
-		fsl_msi_free_hwirqs(msi, *p, *(p + 1));
-
-	return 0;
-}
-
 static int fsl_msi_init_allocator(struct fsl_msi *msi_data)
 {
 	int rc;
-	int size = BITS_TO_LONGS(NR_MSI_IRQS) * sizeof(u32);
 
-	msi_data->fsl_msi_bitmap = kzalloc(size, GFP_KERNEL);
+	rc = msi_bitmap_alloc(&msi_data->bitmap, NR_MSI_IRQS,
+			      msi_data->irqhost->of_node);
+	if (rc)
+		return rc;
 
-	if (msi_data->fsl_msi_bitmap == NULL) {
-		pr_debug("%s: ENOMEM allocating allocator bitmap!\n",
-				__func__);
-		return -ENOMEM;
+	rc = msi_bitmap_reserve_dt_hwirqs(&msi_data->bitmap);
+	if (rc < 0) {
+		msi_bitmap_free(&msi_data->bitmap);
+		return rc;
 	}
 
-	rc = fsl_msi_free_dt_hwirqs(msi_data);
-	if (rc)
-		goto out_free;
-
 	return 0;
-out_free:
-	kfree(msi_data->fsl_msi_bitmap);
-
-	msi_data->fsl_msi_bitmap = NULL;
-	return rc;
-
 }
 
 static int fsl_msi_check_device(struct pci_dev *pdev, int nvec, int type)
@@ -175,7 +101,8 @@ static void fsl_teardown_msi_irqs(struct pci_dev *pdev)
 		if (entry->irq == NO_IRQ)
 			continue;
 		set_irq_msi(entry->irq, NULL);
-		fsl_msi_free_hwirqs(msi_data, virq_to_hw(entry->irq), 1);
+		msi_bitmap_free_hwirqs(&msi_data->bitmap,
+				       virq_to_hw(entry->irq), 1);
 		irq_dispose_mapping(entry->irq);
 	}
 
@@ -197,15 +124,14 @@ static void fsl_compose_msi_msg(struct pci_dev *pdev, int hwirq,
 
 static int fsl_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)
 {
-	irq_hw_number_t hwirq;
-	int rc;
+	int rc, hwirq;
 	unsigned int virq;
 	struct msi_desc *entry;
 	struct msi_msg msg;
 	struct fsl_msi *msi_data = fsl_msi;
 
 	list_for_each_entry(entry, &pdev->msi_list, list) {
-		hwirq = fsl_msi_alloc_hwirqs(msi_data, 1);
+		hwirq = msi_bitmap_alloc_hwirqs(&msi_data->bitmap, 1);
 		if (hwirq < 0) {
 			rc = hwirq;
 			pr_debug("%s: fail allocating msi interrupt\n",
@@ -216,9 +142,9 @@ static int fsl_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)
 		virq = irq_create_mapping(msi_data->irqhost, hwirq);
 
 		if (virq == NO_IRQ) {
-			pr_debug("%s: fail mapping hwirq 0x%lx\n",
+			pr_debug("%s: fail mapping hwirq 0x%x\n",
 					__func__, hwirq);
-			fsl_msi_free_hwirqs(msi_data, hwirq, 1);
+			msi_bitmap_free_hwirqs(&msi_data->bitmap, hwirq, 1);
 			rc = -ENOSPC;
 			goto out_free;
 		}
@@ -317,14 +243,11 @@ static int __devinit fsl_of_msi_probe(struct of_device *dev,
 		goto error_out;
 	}
 
-	msi->of_node = of_node_get(dev->node);
+	msi->irqhost = irq_alloc_host(dev->node, IRQ_HOST_MAP_LINEAR,
+				      NR_MSI_IRQS, &fsl_msi_host_ops, 0);
 
-	msi->irqhost = irq_alloc_host(of_node_get(dev->node),
-				IRQ_HOST_MAP_LINEAR,
-				NR_MSI_IRQS, &fsl_msi_host_ops, 0);
 	if (msi->irqhost == NULL) {
 		dev_err(&dev->dev, "No memory for MSI irqhost\n");
-		of_node_put(dev->node);
 		err = -ENOMEM;
 		goto error_out;
 	}
diff --git a/arch/powerpc/sysdev/fsl_msi.h b/arch/powerpc/sysdev/fsl_msi.h
index a653468521fa..331c7e7025b7 100644
--- a/arch/powerpc/sysdev/fsl_msi.h
+++ b/arch/powerpc/sysdev/fsl_msi.h
@@ -13,6 +13,8 @@
 #ifndef _POWERPC_SYSDEV_FSL_MSI_H
 #define _POWERPC_SYSDEV_FSL_MSI_H
 
+#include <asm/msi_bitmap.h>
+
 #define NR_MSI_REG		8
 #define IRQS_PER_MSI_REG	32
 #define NR_MSI_IRQS	(NR_MSI_REG * IRQS_PER_MSI_REG)
@@ -22,9 +24,6 @@
 #define FSL_PIC_IP_IPIC	0x00000002
 
 struct fsl_msi {
-	/* Device node of the MSI interrupt*/
-	struct device_node *of_node;
-
 	struct irq_host *irqhost;
 
 	unsigned long cascade_irq;
@@ -34,8 +33,7 @@ struct fsl_msi {
 	void __iomem *msi_regs;
 	u32 feature;
 
-	unsigned long *fsl_msi_bitmap;
-	spinlock_t bitmap_lock;
+	struct msi_bitmap bitmap;
 };
 
 #endif /* _POWERPC_SYSDEV_FSL_MSI_H */
diff --git a/arch/powerpc/sysdev/mpic.h b/arch/powerpc/sysdev/mpic.h
index fbf8a266941c..6209c62a426d 100644
--- a/arch/powerpc/sysdev/mpic.h
+++ b/arch/powerpc/sysdev/mpic.h
@@ -14,8 +14,6 @@
 #ifdef CONFIG_PCI_MSI
 extern void mpic_msi_reserve_hwirq(struct mpic *mpic, irq_hw_number_t hwirq);
 extern int mpic_msi_init_allocator(struct mpic *mpic);
-extern irq_hw_number_t mpic_msi_alloc_hwirqs(struct mpic *mpic, int num);
-extern void mpic_msi_free_hwirqs(struct mpic *mpic, int offset, int num);
 extern int mpic_u3msi_init(struct mpic *mpic);
 extern int mpic_pasemi_msi_init(struct mpic *mpic);
 #else
diff --git a/arch/powerpc/sysdev/mpic_msi.c b/arch/powerpc/sysdev/mpic_msi.c
index de3e5e8bc324..1d44eee80fa1 100644
--- a/arch/powerpc/sysdev/mpic_msi.c
+++ b/arch/powerpc/sysdev/mpic_msi.c
@@ -15,59 +15,17 @@
 #include <asm/prom.h>
 #include <asm/hw_irq.h>
 #include <asm/ppc-pci.h>
+#include <asm/msi_bitmap.h>
 
 #include <sysdev/mpic.h>
 
-static void __mpic_msi_reserve_hwirq(struct mpic *mpic, irq_hw_number_t hwirq)
-{
-	pr_debug("mpic: reserving hwirq 0x%lx\n", hwirq);
-	bitmap_allocate_region(mpic->hwirq_bitmap, hwirq, 0);
-}
-
 void mpic_msi_reserve_hwirq(struct mpic *mpic, irq_hw_number_t hwirq)
 {
-	unsigned long flags;
-
 	/* The mpic calls this even when there is no allocator setup */
-	if (!mpic->hwirq_bitmap)
+	if (!mpic->msi_bitmap.bitmap)
 		return;
 
-	spin_lock_irqsave(&mpic->bitmap_lock, flags);
-	__mpic_msi_reserve_hwirq(mpic, hwirq);
-	spin_unlock_irqrestore(&mpic->bitmap_lock, flags);
-}
-
-irq_hw_number_t mpic_msi_alloc_hwirqs(struct mpic *mpic, int num)
-{
-	unsigned long flags;
-	int offset, order = get_count_order(num);
-
-	spin_lock_irqsave(&mpic->bitmap_lock, flags);
-	/*
-	 * This is fast, but stricter than we need. We might want to add
-	 * a fallback routine which does a linear search with no alignment.
-	 */
-	offset = bitmap_find_free_region(mpic->hwirq_bitmap, mpic->irq_count,
-					 order);
-	spin_unlock_irqrestore(&mpic->bitmap_lock, flags);
-
-	pr_debug("mpic: allocated 0x%x (2^%d) at offset 0x%x\n",
-		 num, order, offset);
-
-	return offset;
-}
-
-void mpic_msi_free_hwirqs(struct mpic *mpic, int offset, int num)
-{
-	unsigned long flags;
-	int order = get_count_order(num);
-
-	pr_debug("mpic: freeing 0x%x (2^%d) at offset 0x%x\n",
-		 num, order, offset);
-
-	spin_lock_irqsave(&mpic->bitmap_lock, flags);
-	bitmap_release_region(mpic->hwirq_bitmap, offset, order);
-	spin_unlock_irqrestore(&mpic->bitmap_lock, flags);
+	msi_bitmap_reserve_hwirq(&mpic->msi_bitmap, hwirq);
 }
 
 #ifdef CONFIG_MPIC_U3_HT_IRQS
@@ -83,13 +41,13 @@ static int mpic_msi_reserve_u3_hwirqs(struct mpic *mpic)
 
 	/* Reserve source numbers we know are reserved in the HW */
 	for (i = 0;   i < 8;   i++)
-		__mpic_msi_reserve_hwirq(mpic, i);
+		msi_bitmap_reserve_hwirq(&mpic->msi_bitmap, i);
 
 	for (i = 42;  i < 46;  i++)
-		__mpic_msi_reserve_hwirq(mpic, i);
+		msi_bitmap_reserve_hwirq(&mpic->msi_bitmap, i);
 
 	for (i = 100; i < 105; i++)
-		__mpic_msi_reserve_hwirq(mpic, i);
+		msi_bitmap_reserve_hwirq(&mpic->msi_bitmap, i);
 
 	np = NULL;
 	while ((np = of_find_all_nodes(np))) {
@@ -99,7 +57,7 @@ static int mpic_msi_reserve_u3_hwirqs(struct mpic *mpic)
 		while (of_irq_map_one(np, index++, &oirq) == 0) {
 			ops->xlate(mpic->irqhost, NULL, oirq.specifier,
 						oirq.size, &hwirq, &flags);
-			__mpic_msi_reserve_hwirq(mpic, hwirq);
+			msi_bitmap_reserve_hwirq(&mpic->msi_bitmap, hwirq);
 		}
 	}
 
@@ -112,70 +70,25 @@ static int mpic_msi_reserve_u3_hwirqs(struct mpic *mpic)
 }
 #endif
 
-static int mpic_msi_reserve_dt_hwirqs(struct mpic *mpic)
-{
-	int i, len;
-	const u32 *p;
-
-	p = of_get_property(mpic->irqhost->of_node,
-			    "msi-available-ranges", &len);
-	if (!p) {
-		pr_debug("mpic: no msi-available-ranges property found on %s\n",
-			  mpic->irqhost->of_node->full_name);
-		return -ENODEV;
-	}
-
-	if (len % 8 != 0) {
-		printk(KERN_WARNING "mpic: Malformed msi-available-ranges "
-		       "property on %s\n", mpic->irqhost->of_node->full_name);
-		return -EINVAL;
-	}
-
-	bitmap_allocate_region(mpic->hwirq_bitmap, 0,
-			       get_count_order(mpic->irq_count));
-
-	/* Format is: (<u32 start> <u32 count>)+ */
-	len /= sizeof(u32);
-	for (i = 0; i < len / 2; i++, p += 2)
-		mpic_msi_free_hwirqs(mpic, *p, *(p + 1));
-
-	return 0;
-}
-
 int mpic_msi_init_allocator(struct mpic *mpic)
 {
-	int rc, size;
-
-	BUG_ON(mpic->hwirq_bitmap);
-	spin_lock_init(&mpic->bitmap_lock);
+	int rc;
 
-	size = BITS_TO_LONGS(mpic->irq_count) * sizeof(long);
-	pr_debug("mpic: allocator bitmap size is 0x%x bytes\n", size);
+	rc = msi_bitmap_alloc(&mpic->msi_bitmap, mpic->irq_count,
+			      mpic->irqhost->of_node);
+	if (rc)
+		return rc;
 
-	mpic->hwirq_bitmap = alloc_maybe_bootmem(size, GFP_KERNEL);
-
-	if (!mpic->hwirq_bitmap) {
-		pr_debug("mpic: ENOMEM allocating allocator bitmap!\n");
-		return -ENOMEM;
-	}
-
-	memset(mpic->hwirq_bitmap, 0, size);
-
-	rc = mpic_msi_reserve_dt_hwirqs(mpic);
-	if (rc) {
+	rc = msi_bitmap_reserve_dt_hwirqs(&mpic->msi_bitmap);
+	if (rc > 0) {
 		if (mpic->flags & MPIC_U3_HT_IRQS)
 			rc = mpic_msi_reserve_u3_hwirqs(mpic);
 
-		if (rc)
-			goto out_free;
+		if (rc) {
+			msi_bitmap_free(&mpic->msi_bitmap);
+			return rc;
+		}
 	}
 
 	return 0;
-
- out_free:
-	if (mem_init_done)
-		kfree(mpic->hwirq_bitmap);
-
-	mpic->hwirq_bitmap = NULL;
-	return rc;
 }
diff --git a/arch/powerpc/sysdev/mpic_pasemi_msi.c b/arch/powerpc/sysdev/mpic_pasemi_msi.c
index 68aff6076675..656cb772b691 100644
--- a/arch/powerpc/sysdev/mpic_pasemi_msi.c
+++ b/arch/powerpc/sysdev/mpic_pasemi_msi.c
@@ -22,6 +22,7 @@
 #include <asm/prom.h>
 #include <asm/hw_irq.h>
 #include <asm/ppc-pci.h>
+#include <asm/msi_bitmap.h>
 
 #include "mpic.h"
 
@@ -81,8 +82,8 @@ static void pasemi_msi_teardown_msi_irqs(struct pci_dev *pdev)
 			continue;
 
 		set_irq_msi(entry->irq, NULL);
-		mpic_msi_free_hwirqs(msi_mpic, virq_to_hw(entry->irq),
-				     ALLOC_CHUNK);
+		msi_bitmap_free_hwirqs(&msi_mpic->msi_bitmap,
+				       virq_to_hw(entry->irq), ALLOC_CHUNK);
 		irq_dispose_mapping(entry->irq);
 	}
 
@@ -91,11 +92,10 @@ static void pasemi_msi_teardown_msi_irqs(struct pci_dev *pdev)
 
 static int pasemi_msi_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)
 {
-	irq_hw_number_t hwirq;
 	unsigned int virq;
 	struct msi_desc *entry;
 	struct msi_msg msg;
-	int ret;
+	int hwirq;
 
 	pr_debug("pasemi_msi_setup_msi_irqs, pdev %p nvec %d type %d\n",
 		 pdev, nvec, type);
@@ -109,17 +109,19 @@ static int pasemi_msi_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)
 		 * few MSIs for someone, but restrictions will apply to how the
 		 * sources can be changed independently.
 		 */
-		ret = mpic_msi_alloc_hwirqs(msi_mpic, ALLOC_CHUNK);
-		hwirq = ret;
-		if (ret < 0) {
+		hwirq = msi_bitmap_alloc_hwirqs(&msi_mpic->msi_bitmap,
+						ALLOC_CHUNK);
+		if (hwirq < 0) {
 			pr_debug("pasemi_msi: failed allocating hwirq\n");
 			return hwirq;
 		}
 
 		virq = irq_create_mapping(msi_mpic->irqhost, hwirq);
 		if (virq == NO_IRQ) {
-			pr_debug("pasemi_msi: failed mapping hwirq 0x%lx\n", hwirq);
-			mpic_msi_free_hwirqs(msi_mpic, hwirq, ALLOC_CHUNK);
+			pr_debug("pasemi_msi: failed mapping hwirq 0x%x\n",
+				  hwirq);
+			msi_bitmap_free_hwirqs(&msi_mpic->msi_bitmap, hwirq,
+					       ALLOC_CHUNK);
 			return -ENOSPC;
 		}
 
@@ -133,8 +135,8 @@ static int pasemi_msi_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)
 		set_irq_chip(virq, &mpic_pasemi_msi_chip);
 		set_irq_type(virq, IRQ_TYPE_EDGE_RISING);
 
-		pr_debug("pasemi_msi: allocated virq 0x%x (hw 0x%lx) addr 0x%x\n",
-			  virq, hwirq, msg.address_lo);
+		pr_debug("pasemi_msi: allocated virq 0x%x (hw 0x%x) " \
+			 "addr 0x%x\n", virq, hwirq, msg.address_lo);
 
 		/* Likewise, the device writes [0...511] into the target
 		 * register to generate MSI [512...1023]
diff --git a/arch/powerpc/sysdev/mpic_u3msi.c b/arch/powerpc/sysdev/mpic_u3msi.c
index 6e2f8686fdfc..0a8f5a9e87c9 100644
--- a/arch/powerpc/sysdev/mpic_u3msi.c
+++ b/arch/powerpc/sysdev/mpic_u3msi.c
@@ -16,6 +16,7 @@
 #include <asm/prom.h>
 #include <asm/hw_irq.h>
 #include <asm/ppc-pci.h>
+#include <asm/msi_bitmap.h>
 
 #include "mpic.h"
 
@@ -101,7 +102,8 @@ static void u3msi_teardown_msi_irqs(struct pci_dev *pdev)
 			continue;
 
 		set_irq_msi(entry->irq, NULL);
-		mpic_msi_free_hwirqs(msi_mpic, virq_to_hw(entry->irq), 1);
+		msi_bitmap_free_hwirqs(&msi_mpic->msi_bitmap,
+				       virq_to_hw(entry->irq), 1);
 		irq_dispose_mapping(entry->irq);
 	}
 
@@ -110,29 +112,27 @@ static void u3msi_teardown_msi_irqs(struct pci_dev *pdev)
 
 static int u3msi_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)
 {
-	irq_hw_number_t hwirq;
 	unsigned int virq;
 	struct msi_desc *entry;
 	struct msi_msg msg;
 	u64 addr;
-	int ret;
+	int hwirq;
 
 	addr = find_ht_magic_addr(pdev);
 	msg.address_lo = addr & 0xFFFFFFFF;
 	msg.address_hi = addr >> 32;
 
 	list_for_each_entry(entry, &pdev->msi_list, list) {
-		ret = mpic_msi_alloc_hwirqs(msi_mpic, 1);
-		if (ret < 0) {
+		hwirq = msi_bitmap_alloc_hwirqs(&msi_mpic->msi_bitmap, 1);
+		if (hwirq < 0) {
 			pr_debug("u3msi: failed allocating hwirq\n");
-			return ret;
+			return hwirq;
 		}
-		hwirq = ret;
 
 		virq = irq_create_mapping(msi_mpic->irqhost, hwirq);
 		if (virq == NO_IRQ) {
-			pr_debug("u3msi: failed mapping hwirq 0x%lx\n", hwirq);
-			mpic_msi_free_hwirqs(msi_mpic, hwirq, 1);
+			pr_debug("u3msi: failed mapping hwirq 0x%x\n", hwirq);
+			msi_bitmap_free_hwirqs(&msi_mpic->msi_bitmap, hwirq, 1);
 			return -ENOSPC;
 		}
 
@@ -140,8 +140,8 @@ static int u3msi_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)
 		set_irq_chip(virq, &mpic_u3msi_chip);
 		set_irq_type(virq, IRQ_TYPE_EDGE_RISING);
 
-		pr_debug("u3msi: allocated virq 0x%x (hw 0x%lx) addr 0x%lx\n",
-			  virq, hwirq, addr);
+		pr_debug("u3msi: allocated virq 0x%x (hw 0x%x) addr 0x%lx\n",
+			  virq, hwirq, (unsigned long)addr);
 
 		msg.data = hwirq;
 		write_msi_msg(virq, &msg);
diff --git a/arch/powerpc/sysdev/msi_bitmap.c b/arch/powerpc/sysdev/msi_bitmap.c
new file mode 100644
index 000000000000..f84217b8863a
--- /dev/null
+++ b/arch/powerpc/sysdev/msi_bitmap.c
@@ -0,0 +1,247 @@
+/*
+ * Copyright 2006-2008, 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; version 2 of the
+ * License.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/bitmap.h>
+#include <asm/msi_bitmap.h>
+
+int msi_bitmap_alloc_hwirqs(struct msi_bitmap *bmp, int num)
+{
+	unsigned long flags;
+	int offset, order = get_count_order(num);
+
+	spin_lock_irqsave(&bmp->lock, flags);
+	/*
+	 * This is fast, but stricter than we need. We might want to add
+	 * a fallback routine which does a linear search with no alignment.
+	 */
+	offset = bitmap_find_free_region(bmp->bitmap, bmp->irq_count, order);
+	spin_unlock_irqrestore(&bmp->lock, flags);
+
+	pr_debug("msi_bitmap: allocated 0x%x (2^%d) at offset 0x%x\n",
+		 num, order, offset);
+
+	return offset;
+}
+
+void msi_bitmap_free_hwirqs(struct msi_bitmap *bmp, unsigned int offset,
+			    unsigned int num)
+{
+	unsigned long flags;
+	int order = get_count_order(num);
+
+	pr_debug("msi_bitmap: freeing 0x%x (2^%d) at offset 0x%x\n",
+		 num, order, offset);
+
+	spin_lock_irqsave(&bmp->lock, flags);
+	bitmap_release_region(bmp->bitmap, offset, order);
+	spin_unlock_irqrestore(&bmp->lock, flags);
+}
+
+void msi_bitmap_reserve_hwirq(struct msi_bitmap *bmp, unsigned int hwirq)
+{
+	unsigned long flags;
+
+	pr_debug("msi_bitmap: reserving hwirq 0x%x\n", hwirq);
+
+	spin_lock_irqsave(&bmp->lock, flags);
+	bitmap_allocate_region(bmp->bitmap, hwirq, 0);
+	spin_unlock_irqrestore(&bmp->lock, flags);
+}
+
+/**
+ * msi_bitmap_reserve_dt_hwirqs - Reserve irqs specified in the device tree.
+ * @bmp: pointer to the MSI bitmap.
+ *
+ * Looks in the device tree to see if there is a property specifying which
+ * irqs can be used for MSI. If found those irqs reserved in the device tree
+ * are reserved in the bitmap.
+ *
+ * Returns 0 for success, < 0 if there was an error, and > 0 if no property
+ * was found in the device tree.
+ **/
+int msi_bitmap_reserve_dt_hwirqs(struct msi_bitmap *bmp)
+{
+	int i, j, len;
+	const u32 *p;
+
+	if (!bmp->of_node)
+		return 1;
+
+	p = of_get_property(bmp->of_node, "msi-available-ranges", &len);
+	if (!p) {
+		pr_debug("msi_bitmap: no msi-available-ranges property " \
+			 "found on %s\n", bmp->of_node->full_name);
+		return 1;
+	}
+
+	if (len % (2 * sizeof(u32)) != 0) {
+		printk(KERN_WARNING "msi_bitmap: Malformed msi-available-ranges"
+		       " property on %s\n", bmp->of_node->full_name);
+		return -EINVAL;
+	}
+
+	bitmap_allocate_region(bmp->bitmap, 0, get_count_order(bmp->irq_count));
+
+	spin_lock(&bmp->lock);
+
+	/* Format is: (<u32 start> <u32 count>)+ */
+	len /= 2 * sizeof(u32);
+	for (i = 0; i < len; i++, p += 2) {
+		for (j = 0; j < *(p + 1); j++)
+			bitmap_release_region(bmp->bitmap, *p + j, 0);
+	}
+
+	spin_unlock(&bmp->lock);
+
+	return 0;
+}
+
+int msi_bitmap_alloc(struct msi_bitmap *bmp, unsigned int irq_count,
+		     struct device_node *of_node)
+{
+	int size;
+
+	if (!irq_count)
+		return -EINVAL;
+
+	size = BITS_TO_LONGS(irq_count) * sizeof(long);
+	pr_debug("msi_bitmap: allocator bitmap size is 0x%x bytes\n", size);
+
+	bmp->bitmap = zalloc_maybe_bootmem(size, GFP_KERNEL);
+	if (!bmp->bitmap) {
+		pr_debug("msi_bitmap: ENOMEM allocating allocator bitmap!\n");
+		return -ENOMEM;
+	}
+
+	/* We zalloc'ed the bitmap, so all irqs are free by default */
+	spin_lock_init(&bmp->lock);
+	bmp->of_node = of_node_get(of_node);
+	bmp->irq_count = irq_count;
+
+	return 0;
+}
+
+void msi_bitmap_free(struct msi_bitmap *bmp)
+{
+	/* we can't free the bitmap we don't know if it's bootmem etc. */
+	of_node_put(bmp->of_node);
+	bmp->bitmap = NULL;
+}
+
+#ifdef CONFIG_MSI_BITMAP_SELFTEST
+
+#define check(x)	\
+	if (!(x)) printk("msi_bitmap: test failed at line %d\n", __LINE__);
+
+void test_basics(void)
+{
+	struct msi_bitmap bmp;
+	int i, size = 512;
+
+	/* Can't allocate a bitmap of 0 irqs */
+	check(msi_bitmap_alloc(&bmp, 0, NULL) != 0);
+
+	/* of_node may be NULL */
+	check(0 == msi_bitmap_alloc(&bmp, size, NULL));
+
+	/* Should all be free by default */
+	check(0 == bitmap_find_free_region(bmp.bitmap, size,
+					   get_count_order(size)));
+	bitmap_release_region(bmp.bitmap, 0, get_count_order(size));
+
+	/* With no node, there's no msi-available-ranges, so expect > 0 */
+	check(msi_bitmap_reserve_dt_hwirqs(&bmp) > 0);
+
+	/* Should all still be free */
+	check(0 == bitmap_find_free_region(bmp.bitmap, size,
+					   get_count_order(size)));
+	bitmap_release_region(bmp.bitmap, 0, get_count_order(size));
+
+	/* Check we can fill it up and then no more */
+	for (i = 0; i < size; i++)
+		check(msi_bitmap_alloc_hwirqs(&bmp, 1) >= 0);
+
+	check(msi_bitmap_alloc_hwirqs(&bmp, 1) < 0);
+
+	/* Should all be allocated */
+	check(bitmap_find_free_region(bmp.bitmap, size, 0) < 0);
+
+	/* And if we free one we can then allocate another */
+	msi_bitmap_free_hwirqs(&bmp, size / 2, 1);
+	check(msi_bitmap_alloc_hwirqs(&bmp, 1) == size / 2);
+
+	msi_bitmap_free(&bmp);
+
+	/* Clients may check bitmap == NULL for "not-allocated" */
+	check(bmp.bitmap == NULL);
+
+	kfree(bmp.bitmap);
+}
+
+void test_of_node(void)
+{
+	u32 prop_data[] = { 10, 10, 25, 3, 40, 1, 100, 100, 200, 20 };
+	const char *expected_str = "0-9,20-24,28-39,41-99,220-255";
+	char *prop_name = "msi-available-ranges";
+	char *node_name = "/fakenode";
+	struct device_node of_node;
+	struct property prop;
+	struct msi_bitmap bmp;
+	int size = 256;
+	DECLARE_BITMAP(expected, size);
+
+	/* There should really be a struct device_node allocator */
+	memset(&of_node, 0, sizeof(of_node));
+	kref_init(&of_node.kref);
+	of_node.full_name = node_name;
+
+	check(0 == msi_bitmap_alloc(&bmp, size, &of_node));
+
+	/* No msi-available-ranges, so expect > 0 */
+	check(msi_bitmap_reserve_dt_hwirqs(&bmp) > 0);
+
+	/* Should all still be free */
+	check(0 == bitmap_find_free_region(bmp.bitmap, size,
+					   get_count_order(size)));
+	bitmap_release_region(bmp.bitmap, 0, get_count_order(size));
+
+	/* Now create a fake msi-available-ranges property */
+
+	/* There should really .. oh whatever */
+	memset(&prop, 0, sizeof(prop));
+	prop.name = prop_name;
+	prop.value = &prop_data;
+	prop.length = sizeof(prop_data);
+
+	of_node.properties = &prop;
+
+	/* msi-available-ranges, so expect == 0 */
+	check(msi_bitmap_reserve_dt_hwirqs(&bmp) == 0);
+
+	/* Check we got the expected result */
+	check(0 == bitmap_parselist(expected_str, expected, size));
+	check(bitmap_equal(expected, bmp.bitmap, size));
+
+	msi_bitmap_free(&bmp);
+	kfree(bmp.bitmap);
+}
+
+int msi_bitmap_selftest(void)
+{
+	printk(KERN_DEBUG "Running MSI bitmap self-tests ...\n");
+
+	test_basics();
+	test_of_node();
+
+	return 0;
+}
+late_initcall(msi_bitmap_selftest);
+#endif /* CONFIG_MSI_BITMAP_SELFTEST */