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x86: merge dma_supported

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The code for both arches are very similar, so this patch merge them.

Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
Glauber Costa 2008-04-08 13:20:55 -03:00 committed by Ingo Molnar
parent bca5c09663
commit 8e0c379718
3 changed files with 45 additions and 67 deletions
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44
arch/x86/kernel/pci-dma.c
View file

@ -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;
@ -103,6 +105,48 @@ void __init pci_iommu_alloc(void)
}
#endif
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

24
arch/x86/kernel/pci-dma_32.c
View file

@ -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")) {

44
arch/x86/kernel/pci-dma_64.c
View file

@ -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.