[PATCH] dma: direct: Optimize the code for the dma_direct_free function

From: kunyu
Date: Tue Jun 04 2024 - 04:42:18 EST


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@xxxxxxxxxxxx>
---
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