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authorChristoph Hellwig <hch@lst.de>2022-02-14 11:44:42 +0100
committerChristoph Hellwig <hch@lst.de>2022-04-18 07:21:09 +0200
commita2daa27c0c6137481226aee5b3136e453c642929 (patch)
treebb69da8b22d3fc7a225f78facfa8ec8c13f20036
parent3469d36d470df148e8d940c1a6399510562bf3b0 (diff)
downloadlinux-a2daa27c0c6137481226aee5b3136e453c642929.tar.bz2
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: Christoph Hellwig <hch@lst.de> Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Tested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
-rw-r--r--drivers/xen/swiotlb-xen.c2
-rw-r--r--include/linux/swiotlb.h1
-rw-r--r--kernel/dma/swiotlb.c20
3 files changed, 3 insertions, 20 deletions
diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c
index 47aebd98f52f..485cd06ed39e 100644
--- a/drivers/xen/swiotlb-xen.c
+++ b/drivers/xen/swiotlb-xen.c
@@ -202,7 +202,6 @@ retry:
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 @@ retry:
if (swiotlb_init_with_tbl(start, nslabs, true))
panic("Cannot allocate SWIOTLB buffer");
- swiotlb_set_max_segment(PAGE_SIZE);
}
#endif /* CONFIG_X86 */
diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h
index f6c3638255d5..9fb3a568f0c5 100644
--- a/include/linux/swiotlb.h
+++ b/include/linux/swiotlb.h
@@ -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);
diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
index 98bb0eb44a7b..e0127e397335 100644
--- a/kernel/dma/swiotlb.c
+++ b/kernel/dma/swiotlb.c
@@ -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;
}