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Commit 8e0c3797 authored by Glauber Costa's avatar Glauber Costa Committed by Ingo Molnar
Browse files

x86: merge dma_supported 



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

Signed-off-by: default avatarGlauber Costa <gcosta@redhat.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent bca5c096

arch/x86/kernel/pci-dma.c

+44 −0
Original line number Original line Diff line number Diff line
@@ -14,6 +14,8 @@ EXPORT_SYMBOL(forbid_dac); 
const struct dma_mapping_ops *dma_ops;

const struct dma_mapping_ops *dma_ops;

EXPORT_SYMBOL(dma_ops);

EXPORT_SYMBOL(dma_ops);





int iommu_sac_force __read_mostly = 0;



#ifdef CONFIG_IOMMU_DEBUG

#ifdef CONFIG_IOMMU_DEBUG

int panic_on_overflow __read_mostly = 1;

int panic_on_overflow __read_mostly = 1;

int force_iommu __read_mostly = 1;

int force_iommu __read_mostly = 1;
@@ -103,6 +105,48 @@ void __init pci_iommu_alloc(void) 
}

}

#endif

#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)

static int __init pci_iommu_init(void)

{

{

#ifdef CONFIG_CALGARY_IOMMU

#ifdef CONFIG_CALGARY_IOMMU

arch/x86/kernel/pci-dma_32.c

+0 −24
Original line number Original line Diff line number Diff line
@@ -155,30 +155,6 @@ void *dma_mark_declared_memory_occupied(struct device *dev, 
EXPORT_SYMBOL(dma_mark_declared_memory_occupied);

EXPORT_SYMBOL(dma_mark_declared_memory_occupied);





#ifdef CONFIG_PCI

#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)

static int check_iommu(char *s)

{

{

	if (!strcmp(s, "usedac")) {

	if (!strcmp(s, "usedac")) {

arch/x86/kernel/pci-dma_64.c

+1 −43
Original line number Original line Diff line number Diff line
@@ -24,7 +24,7 @@ EXPORT_SYMBOL(bad_dma_address); 
int iommu_bio_merge __read_mostly = 0;

int iommu_bio_merge __read_mostly = 0;

EXPORT_SYMBOL(iommu_bio_merge);

EXPORT_SYMBOL(iommu_bio_merge);





static int iommu_sac_force __read_mostly = 0;

extern int iommu_sac_force;





int no_iommu __read_mostly;

int no_iommu __read_mostly;

/* Set this to 1 if there is a HW IOMMU in the system */

/* 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);

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

 * See <Documentation/x86_64/boot-options.txt> for the iommu kernel parameter

 * documentation.

 * documentation.