[PATCH 0/3] x86: kill global bad_dma_address variable

[PATCH 0/3] x86: kill global bad_dma_address variable

[FUJITA Tomonori]

This is against -tip.

This patchset kills bad_dma_address variable, the old mechanism to
enable IOMMU drivers to make dma_mapping_error() work in IOMMU's
specific way.

bad_dma_address variable was introduced to enable IOMMU drivers to
make dma_mapping_error() work in IOMMU's specific way. However, it
can't handle systems that use both swiotlb and HW IOMMU. SO we
introduced dma_map_ops->mapping_error to solve that case.

Keeping those two mechanisms is pointless. Let's remove the old one.

=
 arch/x86/include/asm/dma-mapping.h |    5 +++--
 arch/x86/kernel/amd_iommu.c        |   21 ++++++++++-----------
 arch/x86/kernel/pci-calgary_64.c   |   31 +++++++++++++------------------
 arch/x86/kernel/pci-dma.c          |    3 ---
 arch/x86/kernel/pci-gart_64.c      |   18 +++++++++++++-----
 arch/x86/kernel/pci-nommu.c        |    2 +-
 6 files changed, 40 insertions(+), 40 deletions(-)

[PATCH 1/3] gart: add own dma_mapping_error function

[FUJITA Tomonori]

GART IOMMU is the only user of bad_dma_address variable. This patch
converts GART to use the newer mechanism, mapping_error in struct
dma_map_ops, to make dma_mapping_error() work in IOMMU specific way.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
---
 arch/x86/kernel/pci-gart_64.c |   18 +++++++++++++-----
 1 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/arch/x86/kernel/pci-gart_64.c b/arch/x86/kernel/pci-gart_64.c
index 919182e..61c4d1e 100644
--- a/arch/x86/kernel/pci-gart_64.c
+++ b/arch/x86/kernel/pci-gart_64.c
@@ -47,6 +47,8 @@ static unsigned long iommu_pages;	/* .. and in pages */
 
 static u32 *iommu_gatt_base;		/* Remapping table */
 
+static dma_addr_t bad_dma_addr;
+
 /*
  * If this is disabled the IOMMU will use an optimized flushing strategy
  * of only flushing when an mapping is reused. With it true the GART is
@@ -217,7 +219,7 @@ static dma_addr_t dma_map_area(struct device *dev, dma_addr_t phys_mem,
 		if (panic_on_overflow)
 			panic("dma_map_area overflow %lu bytes\n", size);
 		iommu_full(dev, size, dir);
-		return bad_dma_address;
+		return bad_dma_addr;
 	}
 
 	for (i = 0; i < npages; i++) {
@@ -303,7 +305,7 @@ static int dma_map_sg_nonforce(struct device *dev, struct scatterlist *sg,
 
 		if (nonforced_iommu(dev, addr, s->length)) {
 			addr = dma_map_area(dev, addr, s->length, dir, 0);
-			if (addr == bad_dma_address) {
+			if (addr == bad_dma_addr) {
 				if (i > 0)
 					gart_unmap_sg(dev, sg, i, dir, NULL);
 				nents = 0;
@@ -456,7 +458,7 @@ error:
 
 	iommu_full(dev, pages << PAGE_SHIFT, dir);
 	for_each_sg(sg, s, nents, i)
-		s->dma_address = bad_dma_address;
+		s->dma_address = bad_dma_addr;
 	return 0;
 }
 
@@ -480,7 +482,7 @@ gart_alloc_coherent(struct device *dev, size_t size, dma_addr_t *dma_addr,
 				     DMA_BIDIRECTIONAL, align_mask);
 
 		flush_gart();
-		if (paddr != bad_dma_address) {
+		if (paddr != bad_dma_addr) {
 			*dma_addr = paddr;
 			return page_address(page);
 		}
@@ -500,6 +502,11 @@ gart_free_coherent(struct device *dev, size_t size, void *vaddr,
 	free_pages((unsigned long)vaddr, get_order(size));
 }
 
+static int gart_mapping_error(struct device *dev, dma_addr_t dma_addr)
+{
+	return (dma_addr == bad_dma_addr);
+}
+
 static int no_agp;
 
 static __init unsigned long check_iommu_size(unsigned long aper, u64 aper_size)
@@ -687,6 +694,7 @@ static struct dma_map_ops gart_dma_ops = {
 	.unmap_page			= gart_unmap_page,
 	.alloc_coherent			= gart_alloc_coherent,
 	.free_coherent			= gart_free_coherent,
+	.mapping_error			= gart_mapping_error,
 };
 
 static void gart_iommu_shutdown(void)
@@ -785,7 +793,7 @@ int __init gart_iommu_init(void)
 
 	iommu_start = aper_size - iommu_size;
 	iommu_bus_base = info.aper_base + iommu_start;
-	bad_dma_address = iommu_bus_base;
+	bad_dma_addr = iommu_bus_base;
 	iommu_gatt_base = agp_gatt_table + (iommu_start>>PAGE_SHIFT);
 
 	/*
-- 
1.5.6.5

[tip:core/iommu] x86: gart: Add own dma_mapping_error function

[tip-bot for FUJITA Tomonori]

Commit-ID:  42109197eb7c01080eea6d9cd48ca23cbc3c566c
Gitweb:     http://git.kernel.org/tip/42109197eb7c01080eea6d9cd48ca23cbc3c566c
Author:     FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
AuthorDate: Sun, 15 Nov 2009 21:19:52 +0900
Committer:  Ingo Molnar <mingo@elte.hu>
CommitDate: Tue, 17 Nov 2009 07:53:20 +0100

x86: gart: Add own dma_mapping_error function

GART IOMMU is the only user of bad_dma_address variable.

This patch converts GART to use the newer mechanism, fill in
->mapping_error() in struct dma_map_ops, to make
dma_mapping_error() work in IOMMU specific way.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: muli@il.ibm.com
Cc: joerg.roedel@amd.com
LKML-Reference: <1258287594-8777-2-git-send-email-fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 arch/x86/kernel/pci-gart_64.c |   18 +++++++++++++-----
 1 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/arch/x86/kernel/pci-gart_64.c b/arch/x86/kernel/pci-gart_64.c
index 919182e..61c4d1e 100644
--- a/arch/x86/kernel/pci-gart_64.c
+++ b/arch/x86/kernel/pci-gart_64.c
@@ -47,6 +47,8 @@ static unsigned long iommu_pages;	/* .. and in pages */
 
 static u32 *iommu_gatt_base;		/* Remapping table */
 
+static dma_addr_t bad_dma_addr;
+
 /*
  * If this is disabled the IOMMU will use an optimized flushing strategy
  * of only flushing when an mapping is reused. With it true the GART is
@@ -217,7 +219,7 @@ static dma_addr_t dma_map_area(struct device *dev, dma_addr_t phys_mem,
 		if (panic_on_overflow)
 			panic("dma_map_area overflow %lu bytes\n", size);
 		iommu_full(dev, size, dir);
-		return bad_dma_address;
+		return bad_dma_addr;
 	}
 
 	for (i = 0; i < npages; i++) {
@@ -303,7 +305,7 @@ static int dma_map_sg_nonforce(struct device *dev, struct scatterlist *sg,
 
 		if (nonforced_iommu(dev, addr, s->length)) {
 			addr = dma_map_area(dev, addr, s->length, dir, 0);
-			if (addr == bad_dma_address) {
+			if (addr == bad_dma_addr) {
 				if (i > 0)
 					gart_unmap_sg(dev, sg, i, dir, NULL);
 				nents = 0;
@@ -456,7 +458,7 @@ error:
 
 	iommu_full(dev, pages << PAGE_SHIFT, dir);
 	for_each_sg(sg, s, nents, i)
-		s->dma_address = bad_dma_address;
+		s->dma_address = bad_dma_addr;
 	return 0;
 }
 
@@ -480,7 +482,7 @@ gart_alloc_coherent(struct device *dev, size_t size, dma_addr_t *dma_addr,
 				     DMA_BIDIRECTIONAL, align_mask);
 
 		flush_gart();
-		if (paddr != bad_dma_address) {
+		if (paddr != bad_dma_addr) {
 			*dma_addr = paddr;
 			return page_address(page);
 		}
@@ -500,6 +502,11 @@ gart_free_coherent(struct device *dev, size_t size, void *vaddr,
 	free_pages((unsigned long)vaddr, get_order(size));
 }
 
+static int gart_mapping_error(struct device *dev, dma_addr_t dma_addr)
+{
+	return (dma_addr == bad_dma_addr);
+}
+
 static int no_agp;
 
 static __init unsigned long check_iommu_size(unsigned long aper, u64 aper_size)
@@ -687,6 +694,7 @@ static struct dma_map_ops gart_dma_ops = {
 	.unmap_page			= gart_unmap_page,
 	.alloc_coherent			= gart_alloc_coherent,
 	.free_coherent			= gart_free_coherent,
+	.mapping_error			= gart_mapping_error,
 };
 
 static void gart_iommu_shutdown(void)
@@ -785,7 +793,7 @@ int __init gart_iommu_init(void)
 
 	iommu_start = aper_size - iommu_size;
 	iommu_bus_base = info.aper_base + iommu_start;
-	bad_dma_address = iommu_bus_base;
+	bad_dma_addr = iommu_bus_base;
 	iommu_gatt_base = agp_gatt_table + (iommu_start>>PAGE_SHIFT);
 
 	/*

[tip:core/iommu] x86: gart: Clean up the code a bit

[tip-bot for Ingo Molnar]

Commit-ID:  123bf0e2eddcda36a33bdfc87aa1fb07229f07b5
Gitweb:     http://git.kernel.org/tip/123bf0e2eddcda36a33bdfc87aa1fb07229f07b5
Author:     Ingo Molnar <mingo@elte.hu>
AuthorDate: Sun, 15 Nov 2009 21:19:52 +0900
Committer:  Ingo Molnar <mingo@elte.hu>
CommitDate: Tue, 17 Nov 2009 07:57:00 +0100

x86: gart: Clean up the code a bit

Clean up various small stylistic details in the GART code. No
functionality changed.

Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: muli@il.ibm.com
Cc: joerg.roedel@amd.com
LKML-Reference: <1258287594-8777-2-git-send-email-fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 arch/x86/kernel/pci-gart_64.c |  116 +++++++++++++++++++++-------------------
 1 files changed, 61 insertions(+), 55 deletions(-)

diff --git a/arch/x86/kernel/pci-gart_64.c b/arch/x86/kernel/pci-gart_64.c
index 61c4d1e..e6a0d40 100644
--- a/arch/x86/kernel/pci-gart_64.c
+++ b/arch/x86/kernel/pci-gart_64.c
@@ -95,7 +95,7 @@ static unsigned long alloc_iommu(struct device *dev, int size,
 
 	base_index = ALIGN(iommu_bus_base & dma_get_seg_boundary(dev),
 			   PAGE_SIZE) >> PAGE_SHIFT;
-	boundary_size = ALIGN((unsigned long long)dma_get_seg_boundary(dev) + 1,
+	boundary_size = ALIGN((u64)dma_get_seg_boundary(dev) + 1,
 			      PAGE_SIZE) >> PAGE_SHIFT;
 
 	spin_lock_irqsave(&iommu_bitmap_lock, flags);
@@ -297,7 +297,7 @@ static int dma_map_sg_nonforce(struct device *dev, struct scatterlist *sg,
 	int i;
 
 #ifdef CONFIG_IOMMU_DEBUG
-	printk(KERN_DEBUG "dma_map_sg overflow\n");
+	pr_debug("dma_map_sg overflow\n");
 #endif
 
 	for_each_sg(sg, s, nents, i) {
@@ -392,12 +392,14 @@ static int gart_map_sg(struct device *dev, struct scatterlist *sg, int nents,
 	if (!dev)
 		dev = &x86_dma_fallback_dev;
 
-	out = 0;
-	start = 0;
-	start_sg = sgmap = sg;
-	seg_size = 0;
-	max_seg_size = dma_get_max_seg_size(dev);
-	ps = NULL; /* shut up gcc */
+	out		= 0;
+	start		= 0;
+	start_sg	= sg;
+	sgmap		= sg;
+	seg_size	= 0;
+	max_seg_size	= dma_get_max_seg_size(dev);
+	ps		= NULL; /* shut up gcc */
+
 	for_each_sg(sg, s, nents, i) {
 		dma_addr_t addr = sg_phys(s);
 
@@ -420,11 +422,12 @@ static int gart_map_sg(struct device *dev, struct scatterlist *sg, int nents,
 						 sgmap, pages, need) < 0)
 					goto error;
 				out++;
-				seg_size = 0;
-				sgmap = sg_next(sgmap);
-				pages = 0;
-				start = i;
-				start_sg = s;
+
+				seg_size	= 0;
+				sgmap		= sg_next(sgmap);
+				pages		= 0;
+				start		= i;
+				start_sg	= s;
 			}
 		}
 
@@ -523,7 +526,7 @@ static __init unsigned long check_iommu_size(unsigned long aper, u64 aper_size)
 	iommu_size -= round_up(a, PMD_PAGE_SIZE) - a;
 
 	if (iommu_size < 64*1024*1024) {
-		printk(KERN_WARNING
+		pr_warning(
 			"PCI-DMA: Warning: Small IOMMU %luMB."
 			" Consider increasing the AGP aperture in BIOS\n",
 				iommu_size >> 20);
@@ -578,28 +581,32 @@ void set_up_gart_resume(u32 aper_order, u32 aper_alloc)
 	aperture_alloc = aper_alloc;
 }
 
-static int gart_resume(struct sys_device *dev)
+static void gart_fixup_northbridges(struct sys_device *dev)
 {
-	printk(KERN_INFO "PCI-DMA: Resuming GART IOMMU\n");
+	int i;
 
-	if (fix_up_north_bridges) {
-		int i;
+	if (!fix_up_north_bridges)
+		return;
 
-		printk(KERN_INFO "PCI-DMA: Restoring GART aperture settings\n");
+	pr_info("PCI-DMA: Restoring GART aperture settings\n");
 
-		for (i = 0; i < num_k8_northbridges; i++) {
-			struct pci_dev *dev = k8_northbridges[i];
+	for (i = 0; i < num_k8_northbridges; i++) {
+		struct pci_dev *dev = k8_northbridges[i];
 
-			/*
-			 * Don't enable translations just yet.  That is the next
-			 * step.  Restore the pre-suspend aperture settings.
-			 */
-			pci_write_config_dword(dev, AMD64_GARTAPERTURECTL,
-						aperture_order << 1);
-			pci_write_config_dword(dev, AMD64_GARTAPERTUREBASE,
-						aperture_alloc >> 25);
-		}
+		/*
+		 * Don't enable translations just yet.  That is the next
+		 * step.  Restore the pre-suspend aperture settings.
+		 */
+		pci_write_config_dword(dev, AMD64_GARTAPERTURECTL, aperture_order << 1);
+		pci_write_config_dword(dev, AMD64_GARTAPERTUREBASE, aperture_alloc >> 25);
 	}
+}
+
+static int gart_resume(struct sys_device *dev)
+{
+	pr_info("PCI-DMA: Resuming GART IOMMU\n");
+
+	gart_fixup_northbridges(dev);
 
 	enable_gart_translations();
 
@@ -612,15 +619,14 @@ static int gart_suspend(struct sys_device *dev, pm_message_t state)
 }
 
 static struct sysdev_class gart_sysdev_class = {
-	.name = "gart",
-	.suspend = gart_suspend,
-	.resume = gart_resume,
+	.name		= "gart",
+	.suspend	= gart_suspend,
+	.resume		= gart_resume,
 
 };
 
 static struct sys_device device_gart = {
-	.id	= 0,
-	.cls	= &gart_sysdev_class,
+	.cls		= &gart_sysdev_class,
 };
 
 /*
@@ -635,7 +641,8 @@ static __init int init_k8_gatt(struct agp_kern_info *info)
 	void *gatt;
 	int i, error;
 
-	printk(KERN_INFO "PCI-DMA: Disabling AGP.\n");
+	pr_info("PCI-DMA: Disabling AGP.\n");
+
 	aper_size = aper_base = info->aper_size = 0;
 	dev = NULL;
 	for (i = 0; i < num_k8_northbridges; i++) {
@@ -653,6 +660,7 @@ static __init int init_k8_gatt(struct agp_kern_info *info)
 	}
 	if (!aper_base)
 		goto nommu;
+
 	info->aper_base = aper_base;
 	info->aper_size = aper_size >> 20;
 
@@ -675,14 +683,14 @@ static __init int init_k8_gatt(struct agp_kern_info *info)
 
 	flush_gart();
 
-	printk(KERN_INFO "PCI-DMA: aperture base @ %x size %u KB\n",
+	pr_info("PCI-DMA: aperture base @ %x size %u KB\n",
 	       aper_base, aper_size>>10);
 
 	return 0;
 
  nommu:
 	/* Should not happen anymore */
-	printk(KERN_WARNING "PCI-DMA: More than 4GB of RAM and no IOMMU\n"
+	pr_warning("PCI-DMA: More than 4GB of RAM and no IOMMU\n"
 	       "falling back to iommu=soft.\n");
 	return -1;
 }
@@ -744,23 +752,23 @@ int __init gart_iommu_init(void)
 	    !gart_iommu_aperture ||
 	    (no_agp && init_k8_gatt(&info) < 0)) {
 		if (max_pfn > MAX_DMA32_PFN) {
-			printk(KERN_WARNING "More than 4GB of memory "
-			       "but GART IOMMU not available.\n");
-			printk(KERN_WARNING "falling back to iommu=soft.\n");
+			pr_warning("More than 4GB of memory but GART IOMMU not available.\n");
+			pr_warning("falling back to iommu=soft.\n");
 		}
 		return 0;
 	}
 
 	/* need to map that range */
-	aper_size = info.aper_size << 20;
-	aper_base = info.aper_base;
-	end_pfn = (aper_base>>PAGE_SHIFT) + (aper_size>>PAGE_SHIFT);
+	aper_size	= info.aper_size << 20;
+	aper_base	= info.aper_base;
+	end_pfn		= (aper_base>>PAGE_SHIFT) + (aper_size>>PAGE_SHIFT);
+
 	if (end_pfn > max_low_pfn_mapped) {
 		start_pfn = (aper_base>>PAGE_SHIFT);
 		init_memory_mapping(start_pfn<<PAGE_SHIFT, end_pfn<<PAGE_SHIFT);
 	}
 
-	printk(KERN_INFO "PCI-DMA: using GART IOMMU.\n");
+	pr_info("PCI-DMA: using GART IOMMU.\n");
 	iommu_size = check_iommu_size(info.aper_base, aper_size);
 	iommu_pages = iommu_size >> PAGE_SHIFT;
 
@@ -775,8 +783,7 @@ int __init gart_iommu_init(void)
 
 		ret = dma_debug_resize_entries(iommu_pages);
 		if (ret)
-			printk(KERN_DEBUG
-			       "PCI-DMA: Cannot trace all the entries\n");
+			pr_debug("PCI-DMA: Cannot trace all the entries\n");
 	}
 #endif
 
@@ -786,15 +793,14 @@ int __init gart_iommu_init(void)
 	 */
 	iommu_area_reserve(iommu_gart_bitmap, 0, EMERGENCY_PAGES);
 
-	agp_memory_reserved = iommu_size;
-	printk(KERN_INFO
-	       "PCI-DMA: Reserving %luMB of IOMMU area in the AGP aperture\n",
+	pr_info("PCI-DMA: Reserving %luMB of IOMMU area in the AGP aperture\n",
 	       iommu_size >> 20);
 
-	iommu_start = aper_size - iommu_size;
-	iommu_bus_base = info.aper_base + iommu_start;
-	bad_dma_addr = iommu_bus_base;
-	iommu_gatt_base = agp_gatt_table + (iommu_start>>PAGE_SHIFT);
+	agp_memory_reserved	= iommu_size;
+	iommu_start		= aper_size - iommu_size;
+	iommu_bus_base		= info.aper_base + iommu_start;
+	bad_dma_addr		= iommu_bus_base;
+	iommu_gatt_base		= agp_gatt_table + (iommu_start>>PAGE_SHIFT);
 
 	/*
 	 * Unmap the IOMMU part of the GART. The alias of the page is
@@ -816,7 +822,7 @@ int __init gart_iommu_init(void)
 	 * the pages as Not-Present:
 	 */
 	wbinvd();
-	
+
 	/*
 	 * Now all caches are flushed and we can safely enable
 	 * GART hardware.  Doing it early leaves the possibility

[PATCH 2/3] x86: kill bad_dma_address variable

[FUJITA Tomonori]

This kills bad_dma_address variable, the old mechanism to enable IOMMU
drivers to make dma_mapping_error() work in IOMMU's specific way.

bad_dma_address variable was introduced to enable IOMMU drivers to
make dma_mapping_error() work in IOMMU's specific way. However, it
can't handle systems that use both swiotlb and HW IOMMU. SO we
introduced dma_map_ops->mapping_error to solve that case.

Intel VT-d, GART, and swiotlb already use
dma_map_ops->mapping_error. Calgary, AMD IOMMU, and nommu use zero for
an error dma address. This adds DMA_ERROR_CODE and converts them to
use it (as SPARC and POWER does).

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
---
 arch/x86/include/asm/dma-mapping.h |    5 +++--
 arch/x86/kernel/amd_iommu.c        |   21 ++++++++++-----------
 arch/x86/kernel/pci-calgary_64.c   |   22 ++++++++++------------
 arch/x86/kernel/pci-dma.c          |    3 ---
 arch/x86/kernel/pci-nommu.c        |    2 +-
 5 files changed, 24 insertions(+), 29 deletions(-)

diff --git a/arch/x86/include/asm/dma-mapping.h b/arch/x86/include/asm/dma-mapping.h
index 6a25d5d..0f6c02f 100644
--- a/arch/x86/include/asm/dma-mapping.h
+++ b/arch/x86/include/asm/dma-mapping.h
@@ -20,7 +20,8 @@
 # define ISA_DMA_BIT_MASK DMA_BIT_MASK(32)
 #endif
 
-extern dma_addr_t bad_dma_address;
+#define DMA_ERROR_CODE	0
+
 extern int iommu_merge;
 extern struct device x86_dma_fallback_dev;
 extern int panic_on_overflow;
@@ -48,7 +49,7 @@ static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
 	if (ops->mapping_error)
 		return ops->mapping_error(dev, dma_addr);
 
-	return (dma_addr == bad_dma_address);
+	return (dma_addr == DMA_ERROR_CODE);
 }
 
 #define dma_alloc_noncoherent(d, s, h, f) dma_alloc_coherent(d, s, h, f)
diff --git a/arch/x86/kernel/amd_iommu.c b/arch/x86/kernel/amd_iommu.c
index 66237fd..093bd52 100644
--- a/arch/x86/kernel/amd_iommu.c
+++ b/arch/x86/kernel/amd_iommu.c
@@ -928,7 +928,7 @@ static unsigned long dma_ops_alloc_addresses(struct device *dev,
 	}
 
 	if (unlikely(address == -1))
-		address = bad_dma_address;
+		address = DMA_ERROR_CODE;
 
 	WARN_ON((address + (PAGE_SIZE*pages)) > dom->aperture_size);
 
@@ -1544,7 +1544,7 @@ static dma_addr_t dma_ops_domain_map(struct amd_iommu *iommu,
 
 	pte  = dma_ops_get_pte(dom, address);
 	if (!pte)
-		return bad_dma_address;
+		return DMA_ERROR_CODE;
 
 	__pte = paddr | IOMMU_PTE_P | IOMMU_PTE_FC;
 
@@ -1625,7 +1625,7 @@ static dma_addr_t __map_single(struct device *dev,
 retry:
 	address = dma_ops_alloc_addresses(dev, dma_dom, pages, align_mask,
 					  dma_mask);
-	if (unlikely(address == bad_dma_address)) {
+	if (unlikely(address == DMA_ERROR_CODE)) {
 		/*
 		 * setting next_address here will let the address
 		 * allocator only scan the new allocated range in the
@@ -1646,7 +1646,7 @@ retry:
 	start = address;
 	for (i = 0; i < pages; ++i) {
 		ret = dma_ops_domain_map(iommu, dma_dom, start, paddr, dir);
-		if (ret == bad_dma_address)
+		if (ret == DMA_ERROR_CODE)
 			goto out_unmap;
 
 		paddr += PAGE_SIZE;
@@ -1674,7 +1674,7 @@ out_unmap:
 
 	dma_ops_free_addresses(dma_dom, address, pages);
 
-	return bad_dma_address;
+	return DMA_ERROR_CODE;
 }
 
 /*
@@ -1690,7 +1690,7 @@ static void __unmap_single(struct amd_iommu *iommu,
 	dma_addr_t i, start;
 	unsigned int pages;
 
-	if ((dma_addr == bad_dma_address) ||
+	if ((dma_addr == DMA_ERROR_CODE) ||
 	    (dma_addr + size > dma_dom->aperture_size))
 		return;
 
@@ -1732,7 +1732,7 @@ static dma_addr_t map_page(struct device *dev, struct page *page,
 	INC_STATS_COUNTER(cnt_map_single);
 
 	if (!check_device(dev))
-		return bad_dma_address;
+		return DMA_ERROR_CODE;
 
 	dma_mask = *dev->dma_mask;
 
@@ -1743,12 +1743,12 @@ static dma_addr_t map_page(struct device *dev, struct page *page,
 		return (dma_addr_t)paddr;
 
 	if (!dma_ops_domain(domain))
-		return bad_dma_address;
+		return DMA_ERROR_CODE;
 
 	spin_lock_irqsave(&domain->lock, flags);
 	addr = __map_single(dev, iommu, domain->priv, paddr, size, dir, false,
 			    dma_mask);
-	if (addr == bad_dma_address)
+	if (addr == DMA_ERROR_CODE)
 		goto out;
 
 	iommu_completion_wait(iommu);
@@ -1957,7 +1957,7 @@ static void *alloc_coherent(struct device *dev, size_t size,
 	*dma_addr = __map_single(dev, iommu, domain->priv, paddr,
 				 size, DMA_BIDIRECTIONAL, true, dma_mask);
 
-	if (*dma_addr == bad_dma_address) {
+	if (*dma_addr == DMA_ERROR_CODE) {
 		spin_unlock_irqrestore(&domain->lock, flags);
 		goto out_free;
 	}
@@ -2110,7 +2110,6 @@ int __init amd_iommu_init_dma_ops(void)
 		prealloc_protection_domains();
 
 	iommu_detected = 1;
-	bad_dma_address = 0;
 	swiotlb = 0;
 #ifdef CONFIG_GART_IOMMU
 	gart_iommu_aperture_disabled = 1;
diff --git a/arch/x86/kernel/pci-calgary_64.c b/arch/x86/kernel/pci-calgary_64.c
index c84ad03..af9f436 100644
--- a/arch/x86/kernel/pci-calgary_64.c
+++ b/arch/x86/kernel/pci-calgary_64.c
@@ -245,7 +245,7 @@ static unsigned long iommu_range_alloc(struct device *dev,
 			if (panic_on_overflow)
 				panic("Calgary: fix the allocator.\n");
 			else
-				return bad_dma_address;
+				return DMA_ERROR_CODE;
 		}
 	}
 
@@ -261,11 +261,11 @@ static dma_addr_t iommu_alloc(struct device *dev, struct iommu_table *tbl,
 			      void *vaddr, unsigned int npages, int direction)
 {
 	unsigned long entry;
-	dma_addr_t ret = bad_dma_address;
+	dma_addr_t ret = DMA_ERROR_CODE;
 
 	entry = iommu_range_alloc(dev, tbl, npages);
 
-	if (unlikely(entry == bad_dma_address))
+	if (unlikely(entry == DMA_ERROR_CODE))
 		goto error;
 
 	/* set the return dma address */
@@ -280,7 +280,7 @@ static dma_addr_t iommu_alloc(struct device *dev, struct iommu_table *tbl,
 error:
 	printk(KERN_WARNING "Calgary: failed to allocate %u pages in "
 	       "iommu %p\n", npages, tbl);
-	return bad_dma_address;
+	return DMA_ERROR_CODE;
 }
 
 static void iommu_free(struct iommu_table *tbl, dma_addr_t dma_addr,
@@ -291,8 +291,8 @@ static void iommu_free(struct iommu_table *tbl, dma_addr_t dma_addr,
 	unsigned long flags;
 
 	/* were we called with bad_dma_address? */
-	badend = bad_dma_address + (EMERGENCY_PAGES * PAGE_SIZE);
-	if (unlikely((dma_addr >= bad_dma_address) && (dma_addr < badend))) {
+	badend = DMA_ERROR_CODE + (EMERGENCY_PAGES * PAGE_SIZE);
+	if (unlikely((dma_addr >= DMA_ERROR_CODE) && (dma_addr < badend))) {
 		WARN(1, KERN_ERR "Calgary: driver tried unmapping bad DMA "
 		       "address 0x%Lx\n", dma_addr);
 		return;
@@ -374,7 +374,7 @@ static int calgary_map_sg(struct device *dev, struct scatterlist *sg,
 		npages = iommu_num_pages(vaddr, s->length, PAGE_SIZE);
 
 		entry = iommu_range_alloc(dev, tbl, npages);
-		if (entry == bad_dma_address) {
+		if (entry == DMA_ERROR_CODE) {
 			/* makes sure unmap knows to stop */
 			s->dma_length = 0;
 			goto error;
@@ -392,7 +392,7 @@ static int calgary_map_sg(struct device *dev, struct scatterlist *sg,
 error:
 	calgary_unmap_sg(dev, sg, nelems, dir, NULL);
 	for_each_sg(sg, s, nelems, i) {
-		sg->dma_address = bad_dma_address;
+		sg->dma_address = DMA_ERROR_CODE;
 		sg->dma_length = 0;
 	}
 	return 0;
@@ -447,7 +447,7 @@ static void* calgary_alloc_coherent(struct device *dev, size_t size,
 
 	/* set up tces to cover the allocated range */
 	mapping = iommu_alloc(dev, tbl, ret, npages, DMA_BIDIRECTIONAL);
-	if (mapping == bad_dma_address)
+	if (mapping == DMA_ERROR_CODE)
 		goto free;
 	*dma_handle = mapping;
 	return ret;
@@ -728,7 +728,7 @@ static void __init calgary_reserve_regions(struct pci_dev *dev)
 	struct iommu_table *tbl = pci_iommu(dev->bus);
 
 	/* reserve EMERGENCY_PAGES from bad_dma_address and up */
-	iommu_range_reserve(tbl, bad_dma_address, EMERGENCY_PAGES);
+	iommu_range_reserve(tbl, DMA_ERROR_CODE, EMERGENCY_PAGES);
 
 	/* avoid the BIOS/VGA first 640KB-1MB region */
 	/* for CalIOC2 - avoid the entire first MB */
@@ -1359,8 +1359,6 @@ static int __init calgary_iommu_init(void)
 		return ret;
 	}
 
-	bad_dma_address = 0x0;
-
 	return 0;
 }
 
diff --git a/arch/x86/kernel/pci-dma.c b/arch/x86/kernel/pci-dma.c
index bf621b9..afcc58b 100644
--- a/arch/x86/kernel/pci-dma.c
+++ b/arch/x86/kernel/pci-dma.c
@@ -43,9 +43,6 @@ int iommu_detected __read_mostly = 0;
  */
 int iommu_pass_through __read_mostly;
 
-dma_addr_t bad_dma_address __read_mostly = 0;
-EXPORT_SYMBOL(bad_dma_address);
-
 /* Dummy device used for NULL arguments (normally ISA). */
 struct device x86_dma_fallback_dev = {
 	.init_name = "fallback device",
diff --git a/arch/x86/kernel/pci-nommu.c b/arch/x86/kernel/pci-nommu.c
index 875e382..22be12b 100644
--- a/arch/x86/kernel/pci-nommu.c
+++ b/arch/x86/kernel/pci-nommu.c
@@ -33,7 +33,7 @@ static dma_addr_t nommu_map_page(struct device *dev, struct page *page,
 	dma_addr_t bus = page_to_phys(page) + offset;
 	WARN_ON(size == 0);
 	if (!check_addr("map_single", dev, bus, size))
-		return bad_dma_address;
+		return DMA_ERROR_CODE;
 	flush_write_buffers();
 	return bus;
 }
-- 
1.5.6.5

[tip:core/iommu] x86: Kill bad_dma_address variable

[tip-bot for FUJITA Tomonori]

Commit-ID:  8fd524b355daef0945692227e726fb444cebcd4f
Gitweb:     http://git.kernel.org/tip/8fd524b355daef0945692227e726fb444cebcd4f
Author:     FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
AuthorDate: Sun, 15 Nov 2009 21:19:53 +0900
Committer:  Ingo Molnar <mingo@elte.hu>
CommitDate: Tue, 17 Nov 2009 07:53:21 +0100

x86: Kill bad_dma_address variable

This kills bad_dma_address variable, the old mechanism to enable
IOMMU drivers to make dma_mapping_error() work in IOMMU's
specific way.

bad_dma_address variable was introduced to enable IOMMU drivers
to make dma_mapping_error() work in IOMMU's specific way.
However, it can't handle systems that use both swiotlb and HW
IOMMU. SO we introduced dma_map_ops->mapping_error to solve that
case.

Intel VT-d, GART, and swiotlb already use
dma_map_ops->mapping_error. Calgary, AMD IOMMU, and nommu use
zero for an error dma address. This adds DMA_ERROR_CODE and
converts them to use it (as SPARC and POWER does).

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: muli@il.ibm.com
Cc: joerg.roedel@amd.com
LKML-Reference: <1258287594-8777-3-git-send-email-fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 arch/x86/include/asm/dma-mapping.h |    5 +++--
 arch/x86/kernel/amd_iommu.c        |   21 ++++++++++-----------
 arch/x86/kernel/pci-calgary_64.c   |   22 ++++++++++------------
 arch/x86/kernel/pci-dma.c          |    3 ---
 arch/x86/kernel/pci-nommu.c        |    2 +-
 5 files changed, 24 insertions(+), 29 deletions(-)

diff --git a/arch/x86/include/asm/dma-mapping.h b/arch/x86/include/asm/dma-mapping.h
index 6a25d5d..0f6c02f 100644
--- a/arch/x86/include/asm/dma-mapping.h
+++ b/arch/x86/include/asm/dma-mapping.h
@@ -20,7 +20,8 @@
 # define ISA_DMA_BIT_MASK DMA_BIT_MASK(32)
 #endif
 
-extern dma_addr_t bad_dma_address;
+#define DMA_ERROR_CODE	0
+
 extern int iommu_merge;
 extern struct device x86_dma_fallback_dev;
 extern int panic_on_overflow;
@@ -48,7 +49,7 @@ static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
 	if (ops->mapping_error)
 		return ops->mapping_error(dev, dma_addr);
 
-	return (dma_addr == bad_dma_address);
+	return (dma_addr == DMA_ERROR_CODE);
 }
 
 #define dma_alloc_noncoherent(d, s, h, f) dma_alloc_coherent(d, s, h, f)
diff --git a/arch/x86/kernel/amd_iommu.c b/arch/x86/kernel/amd_iommu.c
index 66237fd..093bd52 100644
--- a/arch/x86/kernel/amd_iommu.c
+++ b/arch/x86/kernel/amd_iommu.c
@@ -928,7 +928,7 @@ static unsigned long dma_ops_alloc_addresses(struct device *dev,
 	}
 
 	if (unlikely(address == -1))
-		address = bad_dma_address;
+		address = DMA_ERROR_CODE;
 
 	WARN_ON((address + (PAGE_SIZE*pages)) > dom->aperture_size);
 
@@ -1544,7 +1544,7 @@ static dma_addr_t dma_ops_domain_map(struct amd_iommu *iommu,
 
 	pte  = dma_ops_get_pte(dom, address);
 	if (!pte)
-		return bad_dma_address;
+		return DMA_ERROR_CODE;
 
 	__pte = paddr | IOMMU_PTE_P | IOMMU_PTE_FC;
 
@@ -1625,7 +1625,7 @@ static dma_addr_t __map_single(struct device *dev,
 retry:
 	address = dma_ops_alloc_addresses(dev, dma_dom, pages, align_mask,
 					  dma_mask);
-	if (unlikely(address == bad_dma_address)) {
+	if (unlikely(address == DMA_ERROR_CODE)) {
 		/*
 		 * setting next_address here will let the address
 		 * allocator only scan the new allocated range in the
@@ -1646,7 +1646,7 @@ retry:
 	start = address;
 	for (i = 0; i < pages; ++i) {
 		ret = dma_ops_domain_map(iommu, dma_dom, start, paddr, dir);
-		if (ret == bad_dma_address)
+		if (ret == DMA_ERROR_CODE)
 			goto out_unmap;
 
 		paddr += PAGE_SIZE;
@@ -1674,7 +1674,7 @@ out_unmap:
 
 	dma_ops_free_addresses(dma_dom, address, pages);
 
-	return bad_dma_address;
+	return DMA_ERROR_CODE;
 }
 
 /*
@@ -1690,7 +1690,7 @@ static void __unmap_single(struct amd_iommu *iommu,
 	dma_addr_t i, start;
 	unsigned int pages;
 
-	if ((dma_addr == bad_dma_address) ||
+	if ((dma_addr == DMA_ERROR_CODE) ||
 	    (dma_addr + size > dma_dom->aperture_size))
 		return;
 
@@ -1732,7 +1732,7 @@ static dma_addr_t map_page(struct device *dev, struct page *page,
 	INC_STATS_COUNTER(cnt_map_single);
 
 	if (!check_device(dev))
-		return bad_dma_address;
+		return DMA_ERROR_CODE;
 
 	dma_mask = *dev->dma_mask;
 
@@ -1743,12 +1743,12 @@ static dma_addr_t map_page(struct device *dev, struct page *page,
 		return (dma_addr_t)paddr;
 
 	if (!dma_ops_domain(domain))
-		return bad_dma_address;
+		return DMA_ERROR_CODE;
 
 	spin_lock_irqsave(&domain->lock, flags);
 	addr = __map_single(dev, iommu, domain->priv, paddr, size, dir, false,
 			    dma_mask);
-	if (addr == bad_dma_address)
+	if (addr == DMA_ERROR_CODE)
 		goto out;
 
 	iommu_completion_wait(iommu);
@@ -1957,7 +1957,7 @@ static void *alloc_coherent(struct device *dev, size_t size,
 	*dma_addr = __map_single(dev, iommu, domain->priv, paddr,
 				 size, DMA_BIDIRECTIONAL, true, dma_mask);
 
-	if (*dma_addr == bad_dma_address) {
+	if (*dma_addr == DMA_ERROR_CODE) {
 		spin_unlock_irqrestore(&domain->lock, flags);
 		goto out_free;
 	}
@@ -2110,7 +2110,6 @@ int __init amd_iommu_init_dma_ops(void)
 		prealloc_protection_domains();
 
 	iommu_detected = 1;
-	bad_dma_address = 0;
 	swiotlb = 0;
 #ifdef CONFIG_GART_IOMMU
 	gart_iommu_aperture_disabled = 1;
diff --git a/arch/x86/kernel/pci-calgary_64.c b/arch/x86/kernel/pci-calgary_64.c
index c84ad03..af9f436 100644
--- a/arch/x86/kernel/pci-calgary_64.c
+++ b/arch/x86/kernel/pci-calgary_64.c
@@ -245,7 +245,7 @@ static unsigned long iommu_range_alloc(struct device *dev,
 			if (panic_on_overflow)
 				panic("Calgary: fix the allocator.\n");
 			else
-				return bad_dma_address;
+				return DMA_ERROR_CODE;
 		}
 	}
 
@@ -261,11 +261,11 @@ static dma_addr_t iommu_alloc(struct device *dev, struct iommu_table *tbl,
 			      void *vaddr, unsigned int npages, int direction)
 {
 	unsigned long entry;
-	dma_addr_t ret = bad_dma_address;
+	dma_addr_t ret = DMA_ERROR_CODE;
 
 	entry = iommu_range_alloc(dev, tbl, npages);
 
-	if (unlikely(entry == bad_dma_address))
+	if (unlikely(entry == DMA_ERROR_CODE))
 		goto error;
 
 	/* set the return dma address */
@@ -280,7 +280,7 @@ static dma_addr_t iommu_alloc(struct device *dev, struct iommu_table *tbl,
 error:
 	printk(KERN_WARNING "Calgary: failed to allocate %u pages in "
 	       "iommu %p\n", npages, tbl);
-	return bad_dma_address;
+	return DMA_ERROR_CODE;
 }
 
 static void iommu_free(struct iommu_table *tbl, dma_addr_t dma_addr,
@@ -291,8 +291,8 @@ static void iommu_free(struct iommu_table *tbl, dma_addr_t dma_addr,
 	unsigned long flags;
 
 	/* were we called with bad_dma_address? */
-	badend = bad_dma_address + (EMERGENCY_PAGES * PAGE_SIZE);
-	if (unlikely((dma_addr >= bad_dma_address) && (dma_addr < badend))) {
+	badend = DMA_ERROR_CODE + (EMERGENCY_PAGES * PAGE_SIZE);
+	if (unlikely((dma_addr >= DMA_ERROR_CODE) && (dma_addr < badend))) {
 		WARN(1, KERN_ERR "Calgary: driver tried unmapping bad DMA "
 		       "address 0x%Lx\n", dma_addr);
 		return;
@@ -374,7 +374,7 @@ static int calgary_map_sg(struct device *dev, struct scatterlist *sg,
 		npages = iommu_num_pages(vaddr, s->length, PAGE_SIZE);
 
 		entry = iommu_range_alloc(dev, tbl, npages);
-		if (entry == bad_dma_address) {
+		if (entry == DMA_ERROR_CODE) {
 			/* makes sure unmap knows to stop */
 			s->dma_length = 0;
 			goto error;
@@ -392,7 +392,7 @@ static int calgary_map_sg(struct device *dev, struct scatterlist *sg,
 error:
 	calgary_unmap_sg(dev, sg, nelems, dir, NULL);
 	for_each_sg(sg, s, nelems, i) {
-		sg->dma_address = bad_dma_address;
+		sg->dma_address = DMA_ERROR_CODE;
 		sg->dma_length = 0;
 	}
 	return 0;
@@ -447,7 +447,7 @@ static void* calgary_alloc_coherent(struct device *dev, size_t size,
 
 	/* set up tces to cover the allocated range */
 	mapping = iommu_alloc(dev, tbl, ret, npages, DMA_BIDIRECTIONAL);
-	if (mapping == bad_dma_address)
+	if (mapping == DMA_ERROR_CODE)
 		goto free;
 	*dma_handle = mapping;
 	return ret;
@@ -728,7 +728,7 @@ static void __init calgary_reserve_regions(struct pci_dev *dev)
 	struct iommu_table *tbl = pci_iommu(dev->bus);
 
 	/* reserve EMERGENCY_PAGES from bad_dma_address and up */
-	iommu_range_reserve(tbl, bad_dma_address, EMERGENCY_PAGES);
+	iommu_range_reserve(tbl, DMA_ERROR_CODE, EMERGENCY_PAGES);
 
 	/* avoid the BIOS/VGA first 640KB-1MB region */
 	/* for CalIOC2 - avoid the entire first MB */
@@ -1359,8 +1359,6 @@ static int __init calgary_iommu_init(void)
 		return ret;
 	}
 
-	bad_dma_address = 0x0;
-
 	return 0;
 }
 
diff --git a/arch/x86/kernel/pci-dma.c b/arch/x86/kernel/pci-dma.c
index bf621b9..afcc58b 100644
--- a/arch/x86/kernel/pci-dma.c
+++ b/arch/x86/kernel/pci-dma.c
@@ -43,9 +43,6 @@ int iommu_detected __read_mostly = 0;
  */
 int iommu_pass_through __read_mostly;
 
-dma_addr_t bad_dma_address __read_mostly = 0;
-EXPORT_SYMBOL(bad_dma_address);
-
 /* Dummy device used for NULL arguments (normally ISA). */
 struct device x86_dma_fallback_dev = {
 	.init_name = "fallback device",
diff --git a/arch/x86/kernel/pci-nommu.c b/arch/x86/kernel/pci-nommu.c
index 875e382..22be12b 100644
--- a/arch/x86/kernel/pci-nommu.c
+++ b/arch/x86/kernel/pci-nommu.c
@@ -33,7 +33,7 @@ static dma_addr_t nommu_map_page(struct device *dev, struct page *page,
 	dma_addr_t bus = page_to_phys(page) + offset;
 	WARN_ON(size == 0);
 	if (!check_addr("map_single", dev, bus, size))
-		return bad_dma_address;
+		return DMA_ERROR_CODE;
 	flush_write_buffers();
 	return bus;
 }

[PATCH 3/3] Calgary: remove unnecessary DMA_ERROR_CODE usage

[FUJITA Tomonori]

This cleans up iommu_alloc() a bit and removes unnecessary
DMA_ERROR_CODE usage.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
---
 arch/x86/kernel/pci-calgary_64.c |   15 ++++++---------
 1 files changed, 6 insertions(+), 9 deletions(-)

diff --git a/arch/x86/kernel/pci-calgary_64.c b/arch/x86/kernel/pci-calgary_64.c
index af9f436..849a099 100644
--- a/arch/x86/kernel/pci-calgary_64.c
+++ b/arch/x86/kernel/pci-calgary_64.c
@@ -261,12 +261,15 @@ static dma_addr_t iommu_alloc(struct device *dev, struct iommu_table *tbl,
 			      void *vaddr, unsigned int npages, int direction)
 {
 	unsigned long entry;
-	dma_addr_t ret = DMA_ERROR_CODE;
+	dma_addr_t ret;
 
 	entry = iommu_range_alloc(dev, tbl, npages);
 
-	if (unlikely(entry == DMA_ERROR_CODE))
-		goto error;
+	if (unlikely(entry == DMA_ERROR_CODE)) {
+		printk(KERN_WARNING "Calgary: failed to allocate %u pages in "
+		       "iommu %p\n", npages, tbl);
+		return DMA_ERROR_CODE;
+	}
 
 	/* set the return dma address */
 	ret = (entry << PAGE_SHIFT) | ((unsigned long)vaddr & ~PAGE_MASK);
@@ -274,13 +277,7 @@ static dma_addr_t iommu_alloc(struct device *dev, struct iommu_table *tbl,
 	/* put the TCEs in the HW table */
 	tce_build(tbl, entry, npages, (unsigned long)vaddr & PAGE_MASK,
 		  direction);
-
 	return ret;
-
-error:
-	printk(KERN_WARNING "Calgary: failed to allocate %u pages in "
-	       "iommu %p\n", npages, tbl);
-	return DMA_ERROR_CODE;
 }
 
 static void iommu_free(struct iommu_table *tbl, dma_addr_t dma_addr,
-- 
1.5.6.5

[tip:core/iommu] x86: Calgary: Remove unnecessary DMA_ERROR_CODE usage

[tip-bot for FUJITA Tomonori]

Commit-ID:  1f7564ca831a00b21bb493ef174c845b2ba9e64d
Gitweb:     http://git.kernel.org/tip/1f7564ca831a00b21bb493ef174c845b2ba9e64d
Author:     FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
AuthorDate: Sun, 15 Nov 2009 21:19:54 +0900
Committer:  Ingo Molnar <mingo@elte.hu>
CommitDate: Tue, 17 Nov 2009 07:53:21 +0100

x86: Calgary: Remove unnecessary DMA_ERROR_CODE usage

This cleans up iommu_alloc() a bit and removes unnecessary
DMA_ERROR_CODE usage.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: muli@il.ibm.com
Cc: joerg.roedel@amd.com
LKML-Reference: <1258287594-8777-4-git-send-email-fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 arch/x86/kernel/pci-calgary_64.c |   15 ++++++---------
 1 files changed, 6 insertions(+), 9 deletions(-)

diff --git a/arch/x86/kernel/pci-calgary_64.c b/arch/x86/kernel/pci-calgary_64.c
index af9f436..849a099 100644
--- a/arch/x86/kernel/pci-calgary_64.c
+++ b/arch/x86/kernel/pci-calgary_64.c
@@ -261,12 +261,15 @@ static dma_addr_t iommu_alloc(struct device *dev, struct iommu_table *tbl,
 			      void *vaddr, unsigned int npages, int direction)
 {
 	unsigned long entry;
-	dma_addr_t ret = DMA_ERROR_CODE;
+	dma_addr_t ret;
 
 	entry = iommu_range_alloc(dev, tbl, npages);
 
-	if (unlikely(entry == DMA_ERROR_CODE))
-		goto error;
+	if (unlikely(entry == DMA_ERROR_CODE)) {
+		printk(KERN_WARNING "Calgary: failed to allocate %u pages in "
+		       "iommu %p\n", npages, tbl);
+		return DMA_ERROR_CODE;
+	}
 
 	/* set the return dma address */
 	ret = (entry << PAGE_SHIFT) | ((unsigned long)vaddr & ~PAGE_MASK);
@@ -274,13 +277,7 @@ static dma_addr_t iommu_alloc(struct device *dev, struct iommu_table *tbl,
 	/* put the TCEs in the HW table */
 	tce_build(tbl, entry, npages, (unsigned long)vaddr & PAGE_MASK,
 		  direction);
-
 	return ret;
-
-error:
-	printk(KERN_WARNING "Calgary: failed to allocate %u pages in "
-	       "iommu %p\n", npages, tbl);
-	return DMA_ERROR_CODE;
 }
 
 static void iommu_free(struct iommu_table *tbl, dma_addr_t dma_addr,