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

From: Mike Rapoport
Date: Tue Aug 18 2020 - 11:21:20 EST


From: Mike Rapoport <rppt@xxxxxxxxxxxxx>

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 <rppt@xxxxxxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Reviewed-by: Baoquan He <bhe@xxxxxxxxxx>
---
kernel/dma/contiguous.c | 11 +----------
1 file changed, 1 insertion(+), 10 deletions(-)

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;
}
--
2.26.2