From 9f683dfe8099639f9ac859287744a9ed1c3698a0 Mon Sep 17 00:00:00 2001 From: Petr Tesarik Date: Thu, 10 Jul 2025 10:38:29 +0200 Subject: [PATCH] dma-direct: clean up the logic in __dma_direct_alloc_pages() Convert a goto-based loop to a while() loop. To allow the simplification, return early when allocation from CMA is successful. As a bonus, this early return avoids a repeated dma_coherent_ok() check. No functional change. Signed-off-by: Petr Tesarik Signed-off-by: Marek Szyprowski Link: https://lore.kernel.org/r/20250710083829.1853466-1-ptesarik@suse.com --- kernel/dma/direct.c | 31 +++++++++++++------------------ 1 file changed, 13 insertions(+), 18 deletions(-) diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c index 24c359d9c879..302e89580972 100644 --- a/kernel/dma/direct.c +++ b/kernel/dma/direct.c @@ -120,7 +120,7 @@ static struct page *__dma_direct_alloc_pages(struct device *dev, size_t size, gfp_t gfp, bool allow_highmem) { int node = dev_to_node(dev); - struct page *page = NULL; + struct page *page; u64 phys_limit; WARN_ON_ONCE(!PAGE_ALIGNED(size)); @@ -131,30 +131,25 @@ static struct page *__dma_direct_alloc_pages(struct device *dev, size_t size, gfp |= dma_direct_optimal_gfp_mask(dev, &phys_limit); page = dma_alloc_contiguous(dev, size, gfp); if (page) { - if (!dma_coherent_ok(dev, page_to_phys(page), size) || - (!allow_highmem && PageHighMem(page))) { - dma_free_contiguous(dev, page, size); - page = NULL; - } + if (dma_coherent_ok(dev, page_to_phys(page), size) && + (allow_highmem || !PageHighMem(page))) + return page; + + dma_free_contiguous(dev, page, size); } -again: - if (!page) - page = alloc_pages_node(node, gfp, get_order(size)); - if (page && !dma_coherent_ok(dev, page_to_phys(page), size)) { + + while ((page = alloc_pages_node(node, gfp, get_order(size))) + && !dma_coherent_ok(dev, page_to_phys(page), size)) { __free_pages(page, get_order(size)); - page = NULL; if (IS_ENABLED(CONFIG_ZONE_DMA32) && phys_limit < DMA_BIT_MASK(64) && - !(gfp & (GFP_DMA32 | GFP_DMA))) { + !(gfp & (GFP_DMA32 | GFP_DMA))) gfp |= GFP_DMA32; - goto again; - } - - if (IS_ENABLED(CONFIG_ZONE_DMA) && !(gfp & GFP_DMA)) { + else if (IS_ENABLED(CONFIG_ZONE_DMA) && !(gfp & GFP_DMA)) gfp = (gfp & ~GFP_DMA32) | GFP_DMA; - goto again; - } + else + return NULL; } return page; -- 2.47.3