mirror of
https://github.com/torvalds/linux.git
synced 2024-11-07 04:32:03 +00:00
9c5a362142
The DMA Contiguous Memory Allocator support on x86 is disabled when swiotlb config option is enabled. So DMA CMA is always disabled on x86_64 because swiotlb is always enabled. This attempts to support for DMA CMA with enabling swiotlb config option. The contiguous memory allocator on x86 is integrated in the function dma_generic_alloc_coherent() which is .alloc callback in nommu_dma_ops for dma_alloc_coherent(). x86_swiotlb_alloc_coherent() which is .alloc callback in swiotlb_dma_ops tries to allocate with dma_generic_alloc_coherent() firstly and then swiotlb_alloc_coherent() is called as a fallback. The main part of supporting DMA CMA with swiotlb is that changing x86_swiotlb_free_coherent() which is .free callback in swiotlb_dma_ops for dma_free_coherent() so that it can distinguish memory allocated by dma_generic_alloc_coherent() from one allocated by swiotlb_alloc_coherent() and release it with dma_generic_free_coherent() which can handle contiguous memory. This change requires making is_swiotlb_buffer() global function. This also needs to change .free callback in the dma_map_ops for amd_gart and sta2x11, because these dma_ops are also using dma_generic_alloc_coherent(). Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Acked-by: Marek Szyprowski <m.szyprowski@samsung.com> Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Don Dutile <ddutile@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
113 lines
2.7 KiB
C
113 lines
2.7 KiB
C
/* Glue code to lib/swiotlb.c */
|
|
|
|
#include <linux/pci.h>
|
|
#include <linux/cache.h>
|
|
#include <linux/module.h>
|
|
#include <linux/swiotlb.h>
|
|
#include <linux/bootmem.h>
|
|
#include <linux/dma-mapping.h>
|
|
|
|
#include <asm/iommu.h>
|
|
#include <asm/swiotlb.h>
|
|
#include <asm/dma.h>
|
|
#include <asm/xen/swiotlb-xen.h>
|
|
#include <asm/iommu_table.h>
|
|
int swiotlb __read_mostly;
|
|
|
|
void *x86_swiotlb_alloc_coherent(struct device *hwdev, size_t size,
|
|
dma_addr_t *dma_handle, gfp_t flags,
|
|
struct dma_attrs *attrs)
|
|
{
|
|
void *vaddr;
|
|
|
|
vaddr = dma_generic_alloc_coherent(hwdev, size, dma_handle, flags,
|
|
attrs);
|
|
if (vaddr)
|
|
return vaddr;
|
|
|
|
return swiotlb_alloc_coherent(hwdev, size, dma_handle, flags);
|
|
}
|
|
|
|
void x86_swiotlb_free_coherent(struct device *dev, size_t size,
|
|
void *vaddr, dma_addr_t dma_addr,
|
|
struct dma_attrs *attrs)
|
|
{
|
|
if (is_swiotlb_buffer(dma_to_phys(dev, dma_addr)))
|
|
swiotlb_free_coherent(dev, size, vaddr, dma_addr);
|
|
else
|
|
dma_generic_free_coherent(dev, size, vaddr, dma_addr, attrs);
|
|
}
|
|
|
|
static struct dma_map_ops swiotlb_dma_ops = {
|
|
.mapping_error = swiotlb_dma_mapping_error,
|
|
.alloc = x86_swiotlb_alloc_coherent,
|
|
.free = x86_swiotlb_free_coherent,
|
|
.sync_single_for_cpu = swiotlb_sync_single_for_cpu,
|
|
.sync_single_for_device = swiotlb_sync_single_for_device,
|
|
.sync_sg_for_cpu = swiotlb_sync_sg_for_cpu,
|
|
.sync_sg_for_device = swiotlb_sync_sg_for_device,
|
|
.map_sg = swiotlb_map_sg_attrs,
|
|
.unmap_sg = swiotlb_unmap_sg_attrs,
|
|
.map_page = swiotlb_map_page,
|
|
.unmap_page = swiotlb_unmap_page,
|
|
.dma_supported = NULL,
|
|
};
|
|
|
|
/*
|
|
* pci_swiotlb_detect_override - set swiotlb to 1 if necessary
|
|
*
|
|
* This returns non-zero if we are forced to use swiotlb (by the boot
|
|
* option).
|
|
*/
|
|
int __init pci_swiotlb_detect_override(void)
|
|
{
|
|
int use_swiotlb = swiotlb | swiotlb_force;
|
|
|
|
if (swiotlb_force)
|
|
swiotlb = 1;
|
|
|
|
return use_swiotlb;
|
|
}
|
|
IOMMU_INIT_FINISH(pci_swiotlb_detect_override,
|
|
pci_xen_swiotlb_detect,
|
|
pci_swiotlb_init,
|
|
pci_swiotlb_late_init);
|
|
|
|
/*
|
|
* if 4GB or more detected (and iommu=off not set) return 1
|
|
* and set swiotlb to 1.
|
|
*/
|
|
int __init pci_swiotlb_detect_4gb(void)
|
|
{
|
|
/* don't initialize swiotlb if iommu=off (no_iommu=1) */
|
|
#ifdef CONFIG_X86_64
|
|
if (!no_iommu && max_pfn > MAX_DMA32_PFN)
|
|
swiotlb = 1;
|
|
#endif
|
|
return swiotlb;
|
|
}
|
|
IOMMU_INIT(pci_swiotlb_detect_4gb,
|
|
pci_swiotlb_detect_override,
|
|
pci_swiotlb_init,
|
|
pci_swiotlb_late_init);
|
|
|
|
void __init pci_swiotlb_init(void)
|
|
{
|
|
if (swiotlb) {
|
|
swiotlb_init(0);
|
|
dma_ops = &swiotlb_dma_ops;
|
|
}
|
|
}
|
|
|
|
void __init pci_swiotlb_late_init(void)
|
|
{
|
|
/* An IOMMU turned us off. */
|
|
if (!swiotlb)
|
|
swiotlb_free();
|
|
else {
|
|
printk(KERN_INFO "PCI-DMA: "
|
|
"Using software bounce buffering for IO (SWIOTLB)\n");
|
|
swiotlb_print_info();
|
|
}
|
|
}
|