tools/testing/scatterlist: Fix test to compile and run

Add missing define of ALIGN_DOWN to make the test build and run.  In
addition, __sg_alloc_table_from_pages now support unaligned maximum
segment, so adapt the test result accordingly.

Fixes: 07da122 ("lib/scatterlist: Add support in dynamic allocation of SG table from pages")
Link: https://lore.kernel.org/r/20201115120623.139113-1-leon@kernel.org
Signed-off-by: Maor Gottlieb <maorg@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

Author: maorgottlieb

tools/testing/scatterlist/linux/mm.h

@@ -33,6 +33,7 @@ typedef unsigned long dma_addr_t;
 #define __ALIGN_KERNEL(x, a)		__ALIGN_KERNEL_MASK(x, (typeof(x))(a) - 1)
 #define __ALIGN_KERNEL_MASK(x, mask)	(((x) + (mask)) & ~(mask))
 #define ALIGN(x, a)			__ALIGN_KERNEL((x), (a))
+#define ALIGN_DOWN(x, a)		__ALIGN_KERNEL((x) - ((a) - 1), (a))
 
 #define PAGE_ALIGN(addr) ALIGN(addr, PAGE_SIZE)
 

tools/testing/scatterlist/main.c

@@ -52,9 +52,9 @@ int main(void)
 {
 	const unsigned int sgmax = SCATTERLIST_MAX_SEGMENT;
 	struct test *test, tests[] = {
-		{ -EINVAL, 1, pfn(0), PAGE_SIZE, PAGE_SIZE + 1, 1 },
 		{ -EINVAL, 1, pfn(0), PAGE_SIZE, 0, 1 },
-		{ -EINVAL, 1, pfn(0), PAGE_SIZE, sgmax + 1, 1 },
+		{ 0, 1, pfn(0), PAGE_SIZE, PAGE_SIZE + 1, 1 },
+		{ 0, 1, pfn(0), PAGE_SIZE, sgmax + 1, 1 },
 		{ 0, 1, pfn(0), PAGE_SIZE, sgmax, 1 },
 		{ 0, 1, pfn(0), 1, sgmax, 1 },
 		{ 0, 2, pfn(0, 1), 2 * PAGE_SIZE, sgmax, 1 },