From 7d4dc355c574d414d2402ac481a2fc4ee51e2771 Mon Sep 17 00:00:00 2001 From: Linus Walleij Date: Sun, 27 Sep 2026 11:03:25 +0200 Subject: [PATCH] dmaengine: ste_dma40: Fix LCLA allocation order d40_lcla_allocate() calculates the number of pages needed for LCLA, but passes that raw page count as the allocation order to __get_free_pages(). The same value is later passed to free_pages(). Store the allocation order with get_order() instead, and use a separate byte size for allocation diagnostics, fallback kmalloc() sizing and DMA mapping. Fixes: 508849ade23c ("DMAENGINE: ste_dma40: allocate LCLA dynamically") Reported-by: sashiko-bot@kernel.org Closes: https://lore.kernel.org/dmaengine/20260819225114.AE1511F000E9@smtp.kernel.org/ Assisted-by: LLM Reviewed-by: Frank Li Signed-off-by: Linus Walleij Link: https://patch.msgid.link/20260927-dma40-fixes-v7-12-89f595e8851d@kernel.org Signed-off-by: Vinod Koul --- drivers/dma/ste_dma40.c | 33 ++++++++++++++++----------------- 1 file changed, 16 insertions(+), 17 deletions(-) diff --git a/drivers/dma/ste_dma40.c b/drivers/dma/ste_dma40.c index ee6542491279..f2d9b7fecb93 100644 --- a/drivers/dma/ste_dma40.c +++ b/drivers/dma/ste_dma40.c @@ -426,8 +426,8 @@ struct d40_desc { * @dma_addr: DMA address, if mapped * @base_unaligned: The original kmalloc pointer, if kmalloc is used. * This pointer is only there for clean-up on error. - * @pages: The number of pages needed for all physical channels. - * Only used later for clean-up on error + * @alloc_order: Order used for the LCLA page allocation. + * Only used later for clean-up on error. * @lock: Lock to protect the content in this struct. * @alloc_map: big map over which LCLA entry is own by which job. */ @@ -435,7 +435,7 @@ struct d40_lcla_pool { void *base; dma_addr_t dma_addr; void *base_unaligned; - int pages; + unsigned int alloc_order; spinlock_t lock; struct d40_desc **alloc_map; }; @@ -3598,6 +3598,7 @@ static void __init d40_hw_init(struct d40_base *base) static int __init d40_lcla_allocate(struct d40_base *base) { struct d40_lcla_pool *pool = &base->lcla_pool; + size_t lcla_size = SZ_1K * base->num_phy_chans; unsigned long *page_list; int i, j; int ret; @@ -3613,20 +3614,20 @@ static int __init d40_lcla_allocate(struct d40_base *base) if (!page_list) return -ENOMEM; - /* Calculating how many pages that are required */ - base->lcla_pool.pages = SZ_1K * base->num_phy_chans / PAGE_SIZE; + base->lcla_pool.alloc_order = get_order(lcla_size); for (i = 0; i < MAX_LCLA_ALLOC_ATTEMPTS; i++) { page_list[i] = __get_free_pages(GFP_KERNEL, - base->lcla_pool.pages); + base->lcla_pool.alloc_order); if (!page_list[i]) { - d40_err(base->dev, "Failed to allocate %d pages.\n", - base->lcla_pool.pages); + d40_err(base->dev, "Failed to allocate %zu bytes.\n", + lcla_size); ret = -ENOMEM; for (j = 0; j < i; j++) - free_pages(page_list[j], base->lcla_pool.pages); + free_pages(page_list[j], + base->lcla_pool.alloc_order); goto free_page_list; } @@ -3636,7 +3637,7 @@ static int __init d40_lcla_allocate(struct d40_base *base) } for (j = 0; j < i; j++) - free_pages(page_list[j], base->lcla_pool.pages); + free_pages(page_list[j], base->lcla_pool.alloc_order); if (i < MAX_LCLA_ALLOC_ATTEMPTS) { base->lcla_pool.base = (void *)page_list[i]; @@ -3646,10 +3647,9 @@ static int __init d40_lcla_allocate(struct d40_base *base) * alignment, try with allocating a big buffer. */ dev_warn(base->dev, - "[%s] Failed to get %d pages @ 18 bit align.\n", - __func__, base->lcla_pool.pages); - base->lcla_pool.base_unaligned = kmalloc(SZ_1K * - base->num_phy_chans + + "[%s] Failed to get %zu bytes @ 18 bit align.\n", + __func__, lcla_size); + base->lcla_pool.base_unaligned = kmalloc(lcla_size + LCLA_ALIGNMENT, GFP_KERNEL); if (!base->lcla_pool.base_unaligned) { @@ -3661,8 +3661,7 @@ static int __init d40_lcla_allocate(struct d40_base *base) LCLA_ALIGNMENT); } - pool->dma_addr = dma_map_single(base->dev, pool->base, - SZ_1K * base->num_phy_chans, + pool->dma_addr = dma_map_single(base->dev, pool->base, lcla_size, DMA_TO_DEVICE); if (dma_mapping_error(base->dev, pool->dma_addr)) { pool->dma_addr = 0; @@ -3904,7 +3903,7 @@ static int __init d40_probe(struct platform_device *pdev) if (!base->lcla_pool.base_unaligned && base->lcla_pool.base) free_pages((unsigned long)base->lcla_pool.base, - base->lcla_pool.pages); + base->lcla_pool.alloc_order); kfree(base->lcla_pool.base_unaligned);