[PATCH 1/7] swiotlb: pass bytes instead of nslabs to swiotlb_init_with_tbl

[Christoph Hellwig]

Pass the actual allocation size to swiotlb_init_with_tbl, which
simplifies things quite a bit.

Signed-off-by: Christoph Hellwig <hch at lst.de>
---
 arch/mips/cavium-octeon/dma-octeon.c |  2 +-
 arch/powerpc/platforms/pseries/svm.c |  3 +--
 drivers/xen/swiotlb-xen.c            |  2 +-
 include/linux/swiotlb.h              |  2 +-
 kernel/dma/swiotlb.c                 | 10 +++++-----
 5 files changed, 9 insertions(+), 10 deletions(-)

diff --git a/arch/mips/cavium-octeon/dma-octeon.c b/arch/mips/cavium-octeon/dma-octeon.c
index df70308db0e697..020b8ce5b8ff7c 100644
--- a/arch/mips/cavium-octeon/dma-octeon.c
+++ b/arch/mips/cavium-octeon/dma-octeon.c
@@ -245,6 +245,6 @@ void __init plat_swiotlb_setup(void)
 		panic("%s: Failed to allocate %zu bytes align=%lx\n",
 		      __func__, swiotlbsize, PAGE_SIZE);
 
-	if (swiotlb_init_with_tbl(octeon_swiotlb, swiotlb_nslabs, 1) == -ENOMEM)
+	if (swiotlb_init_with_tbl(octeon_swiotlb, swiotlbsize, 1) == -ENOMEM)
 		panic("Cannot allocate SWIOTLB buffer");
 }
diff --git a/arch/powerpc/platforms/pseries/svm.c b/arch/powerpc/platforms/pseries/svm.c
index 1d829e257996fb..4d281ff56ce96f 100644
--- a/arch/powerpc/platforms/pseries/svm.c
+++ b/arch/powerpc/platforms/pseries/svm.c
@@ -52,10 +52,9 @@ void __init svm_swiotlb_init(void)
 	bytes = io_tlb_nslabs << IO_TLB_SHIFT;
 
 	vstart = memblock_alloc(PAGE_ALIGN(bytes), PAGE_SIZE);
-	if (vstart && !swiotlb_init_with_tbl(vstart, io_tlb_nslabs, false))
+	if (vstart && !swiotlb_init_with_tbl(vstart, bytes, false))
 		return;
 
-
 	memblock_free_early(__pa(vstart),
 			    PAGE_ALIGN(io_tlb_nslabs << IO_TLB_SHIFT));
 	panic("SVM: Cannot allocate SWIOTLB buffer");
diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c
index 4c89afc0df6289..18d79f07b507ce 100644
--- a/drivers/xen/swiotlb-xen.c
+++ b/drivers/xen/swiotlb-xen.c
@@ -249,7 +249,7 @@ void __init xen_swiotlb_init_early(void)
 		panic("%s (rc:%d)", xen_swiotlb_error(XEN_SWIOTLB_EFIXUP), rc);
 	}
 
-	if (swiotlb_init_with_tbl(start, nslabs, false))
+	if (swiotlb_init_with_tbl(start, bytes, false))
 		panic("Cannot allocate SWIOTLB buffer");
 	swiotlb_set_max_segment(PAGE_SIZE);
 }
diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h
index 216854a5e5134b..d1d40ca5014b54 100644
--- a/include/linux/swiotlb.h
+++ b/include/linux/swiotlb.h
@@ -36,7 +36,7 @@ enum swiotlb_force {
 #define IO_TLB_DEFAULT_SIZE (64UL<<20)
 
 extern void swiotlb_init(int verbose);
-int swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose);
+int swiotlb_init_with_tbl(char *tlb, size_t bytes, int verbose);
 unsigned long swiotlb_size_or_default(void);
 extern int swiotlb_late_init_with_tbl(char *tlb, unsigned long nslabs);
 extern int swiotlb_late_init_with_default_size(size_t default_size);
diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
index 0a5b6f7e75bce6..c7b3dd86db7f56 100644
--- a/kernel/dma/swiotlb.c
+++ b/kernel/dma/swiotlb.c
@@ -166,9 +166,9 @@ void __init swiotlb_update_mem_attributes(void)
 	memset(vaddr, 0, bytes);
 }
 
-int __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose)
+int __init swiotlb_init_with_tbl(char *tlb, size_t bytes, int verbose)
 {
-	unsigned long bytes = nslabs << IO_TLB_SHIFT, i;
+	unsigned long nslabs = bytes >> IO_TLB_SHIFT, i;
 	struct io_tlb_mem *mem;
 	size_t alloc_size;
 
@@ -209,17 +209,17 @@ int __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose)
 void  __init
 swiotlb_init(int verbose)
 {
-	size_t bytes = PAGE_ALIGN(default_nslabs << IO_TLB_SHIFT);
+	size_t bytes = default_nslabs << IO_TLB_SHIFT;
 	void *tlb;
 
 	if (swiotlb_force == SWIOTLB_NO_FORCE)
 		return;
 
 	/* Get IO TLB memory from the low pages */
-	tlb = memblock_alloc_low(bytes, PAGE_SIZE);
+	tlb = memblock_alloc_low(PAGE_ALIGN(bytes), PAGE_SIZE);
 	if (!tlb)
 		goto fail;
-	if (swiotlb_init_with_tbl(tlb, default_nslabs, verbose))
+	if (swiotlb_init_with_tbl(tlb, bytes, verbose))
 		goto fail_free_mem;
 	return;
 
-- 
2.30.1