linux-kernel - [PATCH] dma: direct: Optimize the code for the dma_direct

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date: Tue,  4 Jun 2024 16:41:00 +0800
From: kunyu <kunyu@...china.com>
To: hch@....de,
	m.szyprowski@...sung.com,
	robin.murphy@....com
Cc: iommu@...ts.linux.dev,
	linux-kernel@...r.kernel.org,
	kunyu <kunyu@...china.com>
Subject: [PATCH] dma: direct: Optimize the code for the dma_direct_free function

The 'is_swiotlb-for-alloc' and 'dev_isdma_coherent' judgment functions
need to be called multiple times, so they are adjusted to variable
judgment, which can improve code conciseness.

Signed-off-by: kunyu <kunyu@...china.com>
---
 kernel/dma/direct.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c
index 4d543b1e9d57..041e316ad4c0 100644
--- a/kernel/dma/direct.c
+++ b/kernel/dma/direct.c
@@ -315,23 +315,24 @@ void dma_direct_free(struct device *dev, size_t size,
 		void *cpu_addr, dma_addr_t dma_addr, unsigned long attrs)
 {
 	unsigned int page_order = get_order(size);
+	bool swiotlb_for_alloc = is_swiotlb_for_alloc(dev);
+	bool is_dma_coherent = dev_is_dma_coherent(dev);
 
 	if ((attrs & DMA_ATTR_NO_KERNEL_MAPPING) &&
-	    !force_dma_unencrypted(dev) && !is_swiotlb_for_alloc(dev)) {
+	    !force_dma_unencrypted(dev) && !swiotlb_for_alloc) {
 		/* cpu_addr is a struct page cookie, not a kernel address */
 		dma_free_contiguous(dev, cpu_addr, size);
 		return;
 	}
 
 	if (IS_ENABLED(CONFIG_ARCH_HAS_DMA_ALLOC) &&
-	    !dev_is_dma_coherent(dev) &&
-	    !is_swiotlb_for_alloc(dev)) {
+	    !is_dma_coherent && !swiotlb_for_alloc) {
 		arch_dma_free(dev, size, cpu_addr, dma_addr, attrs);
 		return;
 	}
 
 	if (IS_ENABLED(CONFIG_DMA_GLOBAL_POOL) &&
-	    !dev_is_dma_coherent(dev)) {
+	    !is_dma_coherent) {
 		if (!dma_release_from_global_coherent(page_order, cpu_addr))
 			WARN_ON_ONCE(1);
 		return;
-- 
2.18.2