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Subject[PATCH 13/28] x86: merge dma_supported
Date
The code for both arches are very similar, so this patch merge them.

Signed-off-by: Glauber Costa <gcosta@redhat.com>
---
arch/x86/kernel/pci-dma.c | 44 ++++++++++++++++++++++++++++++++++++++++++
arch/x86/kernel/pci-dma_32.c | 24 ----------------------
arch/x86/kernel/pci-dma_64.c | 44 +-----------------------------------------
3 files changed, 45 insertions(+), 67 deletions(-)

diff --git a/arch/x86/kernel/pci-dma.c b/arch/x86/kernel/pci-dma.c
index f6d6a92..4289a9b 100644
--- a/arch/x86/kernel/pci-dma.c
+++ b/arch/x86/kernel/pci-dma.c
@@ -14,6 +14,8 @@ EXPORT_SYMBOL(forbid_dac);
const struct dma_mapping_ops *dma_ops;
EXPORT_SYMBOL(dma_ops);

+int iommu_sac_force __read_mostly = 0;
+
#ifdef CONFIG_IOMMU_DEBUG
int panic_on_overflow __read_mostly = 1;
int force_iommu __read_mostly = 1;
@@ -33,6 +35,48 @@ int dma_set_mask(struct device *dev, u64 mask)
}
EXPORT_SYMBOL(dma_set_mask);

+int dma_supported(struct device *dev, u64 mask)
+{
+#ifdef CONFIG_PCI
+ if (mask > 0xffffffff && forbid_dac > 0) {
+ printk(KERN_INFO "PCI: Disallowing DAC for device %s\n",
+ dev->bus_id);
+ return 0;
+ }
+#endif
+
+ if (dma_ops->dma_supported)
+ return dma_ops->dma_supported(dev, mask);
+
+ /* Copied from i386. Doesn't make much sense, because it will
+ only work for pci_alloc_coherent.
+ The caller just has to use GFP_DMA in this case. */
+ if (mask < DMA_24BIT_MASK)
+ return 0;
+
+ /* Tell the device to use SAC when IOMMU force is on. This
+ allows the driver to use cheaper accesses in some cases.
+
+ Problem with this is that if we overflow the IOMMU area and
+ return DAC as fallback address the device may not handle it
+ correctly.
+
+ As a special case some controllers have a 39bit address
+ mode that is as efficient as 32bit (aic79xx). Don't force
+ SAC for these. Assume all masks <= 40 bits are of this
+ type. Normally this doesn't make any difference, but gives
+ more gentle handling of IOMMU overflow. */
+ if (iommu_sac_force && (mask >= DMA_40BIT_MASK)) {
+ printk(KERN_INFO "%s: Force SAC with mask %Lx\n",
+ dev->bus_id, mask);
+ return 0;
+ }
+
+ return 1;
+}
+EXPORT_SYMBOL(dma_supported);
+
+
static int __init pci_iommu_init(void)
{
#ifdef CONFIG_CALGARY_IOMMU
diff --git a/arch/x86/kernel/pci-dma_32.c b/arch/x86/kernel/pci-dma_32.c
index 6543bb3..1d4091a 100644
--- a/arch/x86/kernel/pci-dma_32.c
+++ b/arch/x86/kernel/pci-dma_32.c
@@ -155,30 +155,6 @@ void *dma_mark_declared_memory_occupied(struct device *dev,
EXPORT_SYMBOL(dma_mark_declared_memory_occupied);

#ifdef CONFIG_PCI
-/* Many VIA bridges seem to corrupt data for DAC. Disable it here */
-
-int
-dma_supported(struct device *dev, u64 mask)
-{
- /*
- * we fall back to GFP_DMA when the mask isn't all 1s,
- * so we can't guarantee allocations that must be
- * within a tighter range than GFP_DMA..
- */
- if (mask < 0x00ffffff)
- return 0;
-
- /* Work around chipset bugs */
- if (forbid_dac > 0 && mask > 0xffffffffULL)
- return 0;
-
- if (dma_ops->dma_supported)
- return dma_ops->dma_supported(dev, mask);
-
- return 1;
-}
-EXPORT_SYMBOL(dma_supported);
-
static int check_iommu(char *s)
{
if (!strcmp(s, "usedac")) {
diff --git a/arch/x86/kernel/pci-dma_64.c b/arch/x86/kernel/pci-dma_64.c
index 7820675..c80da76 100644
--- a/arch/x86/kernel/pci-dma_64.c
+++ b/arch/x86/kernel/pci-dma_64.c
@@ -24,7 +24,7 @@ EXPORT_SYMBOL(bad_dma_address);
int iommu_bio_merge __read_mostly = 0;
EXPORT_SYMBOL(iommu_bio_merge);

-static int iommu_sac_force __read_mostly = 0;
+extern int iommu_sac_force;

int no_iommu __read_mostly;
/* Set this to 1 if there is a HW IOMMU in the system */
@@ -161,48 +161,6 @@ void dma_free_coherent(struct device *dev, size_t size,
}
EXPORT_SYMBOL(dma_free_coherent);

-int dma_supported(struct device *dev, u64 mask)
-{
-#ifdef CONFIG_PCI
- if (mask > 0xffffffff && forbid_dac > 0) {
-
-
-
- printk(KERN_INFO "PCI: Disallowing DAC for device %s\n", dev->bus_id);
- return 0;
- }
-#endif
-
- if (dma_ops->dma_supported)
- return dma_ops->dma_supported(dev, mask);
-
- /* Copied from i386. Doesn't make much sense, because it will
- only work for pci_alloc_coherent.
- The caller just has to use GFP_DMA in this case. */
- if (mask < DMA_24BIT_MASK)
- return 0;
-
- /* Tell the device to use SAC when IOMMU force is on. This
- allows the driver to use cheaper accesses in some cases.
-
- Problem with this is that if we overflow the IOMMU area and
- return DAC as fallback address the device may not handle it
- correctly.
-
- As a special case some controllers have a 39bit address
- mode that is as efficient as 32bit (aic79xx). Don't force
- SAC for these. Assume all masks <= 40 bits are of this
- type. Normally this doesn't make any difference, but gives
- more gentle handling of IOMMU overflow. */
- if (iommu_sac_force && (mask >= DMA_40BIT_MASK)) {
- printk(KERN_INFO "%s: Force SAC with mask %Lx\n", dev->bus_id,mask);
- return 0;
- }
-
- return 1;
-}
-EXPORT_SYMBOL(dma_supported);
-
/*
* See <Documentation/x86_64/boot-options.txt> for the iommu kernel parameter
* documentation.
--
1.5.0.6


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