[v3,02/17] dma-contiguous: simplify cma_early_percent_memory()

Commit Message

Mike Rapoport Aug. 18, 2020, 3:16 p.m. UTC

From: Mike Rapoport <[e-mail]>

The memory size calculation in cma_early_percent_memory() traverses
memblock.memory rather than simply call memblock_phys_mem_size(). The
comment in that function suggests that at some point there should have been
call to memblock_analyze() before memblock_phys_mem_size() could be used.
As of now, there is no memblock_analyze() at all and
memblock_phys_mem_size() can be used as soon as cold-plug memory is
registerd with memblock.

Replace loop over memblock.memory with a call to memblock_phys_mem_size().

Signed-off-by: Mike Rapoport <[e-mail]>
Reviewed-by: Christoph Hellwig <[e-mail]>
Reviewed-by: Baoquan He <[e-mail]>
---
 kernel/dma/contiguous.c | 11 +----------
 1 file changed, 1 insertion(+), 10 deletions(-)

Patch

diff --git a/kernel/dma/contiguous.c b/kernel/dma/contiguous.c
index cff7e60968b9..0369fd5fda8f 100644
--- a/kernel/dma/contiguous.c
+++ b/kernel/dma/contiguous.c
@@ -73,16 +73,7 @@  early_param("cma", early_cma);
 
 static phys_addr_t __init __maybe_unused cma_early_percent_memory(void)
 {
-	struct memblock_region *reg;
-	unsigned long total_pages = 0;
-
-	/*
-	 * We cannot use memblock_phys_mem_size() here, because
-	 * memblock_analyze() has not been called yet.
-	 */
-	for_each_memblock(memory, reg)
-		total_pages += memblock_region_memory_end_pfn(reg) -
-			       memblock_region_memory_base_pfn(reg);
+	unsigned long total_pages = PHYS_PFN(memblock_phys_mem_size());
 
 	return (total_pages * CONFIG_CMA_SIZE_PERCENTAGE / 100) << PAGE_SHIFT;
 }