linux_dsm_epyc7002/arch/x86/kernel/pci-swiotlb.c
FUJITA Tomonori 273bee27fa x86: Fix iommu=soft boot option
iommu=soft boot option forces the kernel to use swiotlb.

( This has the side-effect of enabling the swiotlb over the
  GART if this boot option is provided. This is the desired
  behavior of the swiotlb boot option and works like that
  for all other hw-IOMMU drivers. )

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: yinghai@kernel.org
LKML-Reference: <20091125084611O.fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-25 10:12:51 +01:00

70 lines
1.7 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>
int swiotlb __read_mostly;
static void *x86_swiotlb_alloc_coherent(struct device *hwdev, size_t size,
dma_addr_t *dma_handle, gfp_t flags)
{
void *vaddr;
vaddr = dma_generic_alloc_coherent(hwdev, size, dma_handle, flags);
if (vaddr)
return vaddr;
return swiotlb_alloc_coherent(hwdev, size, dma_handle, flags);
}
static struct dma_map_ops swiotlb_dma_ops = {
.mapping_error = swiotlb_dma_mapping_error,
.alloc_coherent = x86_swiotlb_alloc_coherent,
.free_coherent = swiotlb_free_coherent,
.sync_single_for_cpu = swiotlb_sync_single_for_cpu,
.sync_single_for_device = swiotlb_sync_single_for_device,
.sync_single_range_for_cpu = swiotlb_sync_single_range_for_cpu,
.sync_single_range_for_device = swiotlb_sync_single_range_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_init - initialize swiotlb if necessary
*
* This returns non-zero if we are forced to use swiotlb (by the boot
* option).
*/
int __init pci_swiotlb_init(void)
{
int use_swiotlb = swiotlb | swiotlb_force;
/* 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
if (swiotlb_force)
swiotlb = 1;
if (swiotlb) {
swiotlb_init(0);
dma_ops = &swiotlb_dma_ops;
}
return use_swiotlb;
}