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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 <ptesarik@suse.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Link: https://lore.kernel.org/r/20250710083829.1853466-1-ptesarik@suse.com

authored by

Petr Tesarik and committed by
Marek Szyprowski 9f683dfe 8f5ae30d

+13 -18
+13 -18
kernel/dma/direct.c
··· 120 120 gfp_t gfp, bool allow_highmem) 121 121 { 122 122 int node = dev_to_node(dev); 123 - struct page *page = NULL; 123 + struct page *page; 124 124 u64 phys_limit; 125 125 126 126 WARN_ON_ONCE(!PAGE_ALIGNED(size)); ··· 131 131 gfp |= dma_direct_optimal_gfp_mask(dev, &phys_limit); 132 132 page = dma_alloc_contiguous(dev, size, gfp); 133 133 if (page) { 134 - if (!dma_coherent_ok(dev, page_to_phys(page), size) || 135 - (!allow_highmem && PageHighMem(page))) { 136 - dma_free_contiguous(dev, page, size); 137 - page = NULL; 138 - } 134 + if (dma_coherent_ok(dev, page_to_phys(page), size) && 135 + (allow_highmem || !PageHighMem(page))) 136 + return page; 137 + 138 + dma_free_contiguous(dev, page, size); 139 139 } 140 - again: 141 - if (!page) 142 - page = alloc_pages_node(node, gfp, get_order(size)); 143 - if (page && !dma_coherent_ok(dev, page_to_phys(page), size)) { 140 + 141 + while ((page = alloc_pages_node(node, gfp, get_order(size))) 142 + && !dma_coherent_ok(dev, page_to_phys(page), size)) { 144 143 __free_pages(page, get_order(size)); 145 - page = NULL; 146 144 147 145 if (IS_ENABLED(CONFIG_ZONE_DMA32) && 148 146 phys_limit < DMA_BIT_MASK(64) && 149 - !(gfp & (GFP_DMA32 | GFP_DMA))) { 147 + !(gfp & (GFP_DMA32 | GFP_DMA))) 150 148 gfp |= GFP_DMA32; 151 - goto again; 152 - } 153 - 154 - if (IS_ENABLED(CONFIG_ZONE_DMA) && !(gfp & GFP_DMA)) { 149 + else if (IS_ENABLED(CONFIG_ZONE_DMA) && !(gfp & GFP_DMA)) 155 150 gfp = (gfp & ~GFP_DMA32) | GFP_DMA; 156 - goto again; 157 - } 151 + else 152 + return NULL; 158 153 } 159 154 160 155 return page;