kernel-ark/include/linux/swiotlb.h
Yinghai Lu c729de8fce x86, kdump: Set crashkernel_low automatically
Chao said that kdump does does work well on his system on 3.8
without extra parameter, even iommu does not work with kdump.
And now have to append crashkernel_low=Y in first kernel to make
kdump work.

We have now modified crashkernel=X to allocate memory beyong 4G (if
available) and do not allocate low range for crashkernel if the user
does not specify that with crashkernel_low=Y.  This causes regression
if iommu is not enabled.  Without iommu, swiotlb needs to be setup in
first 4G and there is no low memory available to second kernel.

Set crashkernel_low automatically if the user does not specify that.

For system that does support IOMMU with kdump properly, user could
specify crashkernel_low=0 to save that 72M low ram.

-v3: add swiotlb_size() according to Konrad.
-v4: add comments what 8M is for according to hpa.
     also update more crashkernel_low= in kernel-parameters.txt
-v5: update changelog according to Vivek.
-v6: Change description about swiotlb referring according to HATAYAMA.

Reported-by: WANG Chao <chaowang@redhat.com>
Tested-by: WANG Chao <chaowang@redhat.com>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/1366089828-19692-2-git-send-email-yinghai@kernel.org
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2013-04-17 12:35:32 -07:00

120 lines
3.5 KiB
C

#ifndef __LINUX_SWIOTLB_H
#define __LINUX_SWIOTLB_H
#include <linux/types.h>
struct device;
struct dma_attrs;
struct scatterlist;
extern int swiotlb_force;
/*
* Maximum allowable number of contiguous slabs to map,
* must be a power of 2. What is the appropriate value ?
* The complexity of {map,unmap}_single is linearly dependent on this value.
*/
#define IO_TLB_SEGSIZE 128
/*
* log of the size of each IO TLB slab. The number of slabs is command line
* controllable.
*/
#define IO_TLB_SHIFT 11
extern void swiotlb_init(int verbose);
int swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose);
extern unsigned long swiotlb_nr_tbl(void);
unsigned long swiotlb_size_or_default(void);
extern int swiotlb_late_init_with_tbl(char *tlb, unsigned long nslabs);
/*
* Enumeration for sync targets
*/
enum dma_sync_target {
SYNC_FOR_CPU = 0,
SYNC_FOR_DEVICE = 1,
};
/* define the last possible byte of physical address space as a mapping error */
#define SWIOTLB_MAP_ERROR (~(phys_addr_t)0x0)
extern phys_addr_t swiotlb_tbl_map_single(struct device *hwdev,
dma_addr_t tbl_dma_addr,
phys_addr_t phys, size_t size,
enum dma_data_direction dir);
extern void swiotlb_tbl_unmap_single(struct device *hwdev,
phys_addr_t tlb_addr,
size_t size, enum dma_data_direction dir);
extern void swiotlb_tbl_sync_single(struct device *hwdev,
phys_addr_t tlb_addr,
size_t size, enum dma_data_direction dir,
enum dma_sync_target target);
/* Accessory functions. */
extern void
*swiotlb_alloc_coherent(struct device *hwdev, size_t size,
dma_addr_t *dma_handle, gfp_t flags);
extern void
swiotlb_free_coherent(struct device *hwdev, size_t size,
void *vaddr, dma_addr_t dma_handle);
extern dma_addr_t swiotlb_map_page(struct device *dev, struct page *page,
unsigned long offset, size_t size,
enum dma_data_direction dir,
struct dma_attrs *attrs);
extern void swiotlb_unmap_page(struct device *hwdev, dma_addr_t dev_addr,
size_t size, enum dma_data_direction dir,
struct dma_attrs *attrs);
extern int
swiotlb_map_sg(struct device *hwdev, struct scatterlist *sg, int nents,
enum dma_data_direction dir);
extern void
swiotlb_unmap_sg(struct device *hwdev, struct scatterlist *sg, int nents,
enum dma_data_direction dir);
extern int
swiotlb_map_sg_attrs(struct device *hwdev, struct scatterlist *sgl, int nelems,
enum dma_data_direction dir, struct dma_attrs *attrs);
extern void
swiotlb_unmap_sg_attrs(struct device *hwdev, struct scatterlist *sgl,
int nelems, enum dma_data_direction dir,
struct dma_attrs *attrs);
extern void
swiotlb_sync_single_for_cpu(struct device *hwdev, dma_addr_t dev_addr,
size_t size, enum dma_data_direction dir);
extern void
swiotlb_sync_sg_for_cpu(struct device *hwdev, struct scatterlist *sg,
int nelems, enum dma_data_direction dir);
extern void
swiotlb_sync_single_for_device(struct device *hwdev, dma_addr_t dev_addr,
size_t size, enum dma_data_direction dir);
extern void
swiotlb_sync_sg_for_device(struct device *hwdev, struct scatterlist *sg,
int nelems, enum dma_data_direction dir);
extern int
swiotlb_dma_mapping_error(struct device *hwdev, dma_addr_t dma_addr);
extern int
swiotlb_dma_supported(struct device *hwdev, u64 mask);
#ifdef CONFIG_SWIOTLB
extern void __init swiotlb_free(void);
#else
static inline void swiotlb_free(void) { }
#endif
extern void swiotlb_print_info(void);
#endif /* __LINUX_SWIOTLB_H */