Commit a2daa27c authored by Christoph Hellwig's avatar Christoph Hellwig
Browse files

swiotlb: simplify swiotlb_max_segment 



Remove the bogus Xen override that was usually larger than the actual
size and just calculate the value on demand.  Note that
swiotlb_max_segment still doesn't make sense as an interface and should
eventually be removed.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarAnshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: default avatarKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Tested-by: default avatarBoris Ostrovsky <boris.ostrovsky@oracle.com>
parent 3469d36d

drivers/xen/swiotlb-xen.c

+0 −2
Original line number Diff line number Diff line
@@ -202,7 +202,6 @@ int xen_swiotlb_init(void) 
	rc = swiotlb_late_init_with_tbl(start, nslabs);

	if (rc)

		return rc;

	swiotlb_set_max_segment(PAGE_SIZE);

	return 0;

error:

	if (nslabs > 1024 && repeat--) {
@@ -254,7 +253,6 @@ void __init xen_swiotlb_init_early(void) 


	if (swiotlb_init_with_tbl(start, nslabs, true))

		panic("Cannot allocate SWIOTLB buffer");

	swiotlb_set_max_segment(PAGE_SIZE);

}

#endif /* CONFIG_X86 */

include/linux/swiotlb.h

+0 −1
Original line number Diff line number Diff line
@@ -164,7 +164,6 @@ static inline void swiotlb_adjust_size(unsigned long size) 
#endif /* CONFIG_SWIOTLB */



extern void swiotlb_print_info(void);

extern void swiotlb_set_max_segment(unsigned int);



#ifdef CONFIG_DMA_RESTRICTED_POOL

struct page *swiotlb_alloc(struct device *dev, size_t size);

kernel/dma/swiotlb.c

+3 −17
Original line number Diff line number Diff line
@@ -68,12 +68,6 @@ struct io_tlb_mem io_tlb_default_mem; 


phys_addr_t swiotlb_unencrypted_base;



/*

 * Max segment that we can provide which (if pages are contingous) will

 * not be bounced (unless SWIOTLB_FORCE is set).

 */

static unsigned int max_segment;



static unsigned long default_nslabs = IO_TLB_DEFAULT_SIZE >> IO_TLB_SHIFT;



static int __init
@@ -97,18 +91,12 @@ early_param("swiotlb", setup_io_tlb_npages); 


unsigned int swiotlb_max_segment(void)

{

	return io_tlb_default_mem.nslabs ? max_segment : 0;

	if (!io_tlb_default_mem.nslabs)

		return 0;

	return rounddown(io_tlb_default_mem.nslabs << IO_TLB_SHIFT, PAGE_SIZE);

}

EXPORT_SYMBOL_GPL(swiotlb_max_segment);



void swiotlb_set_max_segment(unsigned int val)

{

	if (swiotlb_force == SWIOTLB_FORCE)

		max_segment = 1;

	else

		max_segment = rounddown(val, PAGE_SIZE);

}



unsigned long swiotlb_size_or_default(void)

{

	return default_nslabs << IO_TLB_SHIFT;
@@ -258,7 +246,6 @@ int __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose) 


	if (verbose)

		swiotlb_print_info();

	swiotlb_set_max_segment(mem->nslabs << IO_TLB_SHIFT);

	return 0;

}
@@ -359,7 +346,6 @@ swiotlb_late_init_with_tbl(char *tlb, unsigned long nslabs) 
	swiotlb_init_io_tlb_mem(mem, virt_to_phys(tlb), nslabs, true);



	swiotlb_print_info();

	swiotlb_set_max_segment(mem->nslabs << IO_TLB_SHIFT);

	return 0;

}