diff mbox series

[02/15] dma-contiguous: simplify cma_early_percent_memory()

Message ID 20200728051153.1590-3-rppt@kernel.org (mailing list archive)
State Superseded
Headers show
Series memblock: seasonal cleaning^w cleanup | expand

Commit Message

Mike Rapoport July 28, 2020, 5:11 a.m. UTC 
From: Mike Rapoport <rppt@linux.ibm.com>

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@linux.ibm.com>
---
 kernel/dma/contiguous.c | 11 +----------
 1 file changed, 1 insertion(+), 10 deletions(-)

Comments

Christoph Hellwig July 28, 2020, 6:37 a.m. UTC | #1 
On Tue, Jul 28, 2020 at 08:11:40AM +0300, Mike Rapoport wrote:
> From: Mike Rapoport <rppt@linux.ibm.com>
> 
> 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@linux.ibm.com>

Looks good:

Reviewed-by: Christoph Hellwig <hch@lst.de>
diff mbox series

Patch

diff --git a/kernel/dma/contiguous.c b/kernel/dma/contiguous.c
index 15bc5026c485..1992afd8ca7b 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;
 }