[PATCH v3 1/6] staging: vchiq_core: Locally cache cache_line_size information

From: Umang Jain
Date: Sat Oct 12 2024 - 14:57:30 EST


Locally cache 'cache_line_size' information in a variable instead of
repeatedly accessing it from drv_mgmt->info. This helps to reflow lines
under 80 columns.

No functional change intended in this patch.

Signed-off-by: Umang Jain <umang.jain@xxxxxxxxxxxxxxxx>
Reviewed-by: Stefan Wahren <wahrenst@xxxxxxx>
---
.../interface/vchiq_arm/vchiq_core.c | 19 +++++++++++--------
1 file changed, 11 insertions(+), 8 deletions(-)

diff --git a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.c b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.c
index 1e4b2978c186..e9b60dd8d419 100644
--- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.c
+++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.c
@@ -1490,6 +1490,7 @@ create_pagelist(struct vchiq_instance *instance, char *buf, char __user *ubuf,
size_t pagelist_size;
struct scatterlist *scatterlist, *sg;
int dma_buffers;
+ unsigned int cache_line_size;
dma_addr_t dma_addr;

if (count >= INT_MAX - PAGE_SIZE)
@@ -1638,10 +1639,10 @@ create_pagelist(struct vchiq_instance *instance, char *buf, char __user *ubuf,
}

/* Partial cache lines (fragments) require special measures */
+ cache_line_size = drv_mgmt->info->cache_line_size;
if ((type == PAGELIST_READ) &&
- ((pagelist->offset & (drv_mgmt->info->cache_line_size - 1)) ||
- ((pagelist->offset + pagelist->length) &
- (drv_mgmt->info->cache_line_size - 1)))) {
+ ((pagelist->offset & (cache_line_size - 1)) ||
+ ((pagelist->offset + pagelist->length) & (cache_line_size - 1)))) {
char *fragments;

if (down_interruptible(&drv_mgmt->free_fragments_sema)) {
@@ -1671,6 +1672,7 @@ free_pagelist(struct vchiq_instance *instance, struct vchiq_pagelist_info *pagel
struct pagelist *pagelist = pagelistinfo->pagelist;
struct page **pages = pagelistinfo->pages;
unsigned int num_pages = pagelistinfo->num_pages;
+ unsigned int cache_line_size;

dev_dbg(instance->state->dev, "arm: %pK, %d\n", pagelistinfo->pagelist, actual);

@@ -1685,16 +1687,17 @@ free_pagelist(struct vchiq_instance *instance, struct vchiq_pagelist_info *pagel
pagelistinfo->scatterlist_mapped = 0;

/* Deal with any partial cache lines (fragments) */
+ cache_line_size = drv_mgmt->info->cache_line_size;
if (pagelist->type >= PAGELIST_READ_WITH_FRAGMENTS && drv_mgmt->fragments_base) {
char *fragments = drv_mgmt->fragments_base +
(pagelist->type - PAGELIST_READ_WITH_FRAGMENTS) *
drv_mgmt->fragments_size;
int head_bytes, tail_bytes;

- head_bytes = (drv_mgmt->info->cache_line_size - pagelist->offset) &
- (drv_mgmt->info->cache_line_size - 1);
+ head_bytes = (cache_line_size - pagelist->offset) &
+ (cache_line_size - 1);
tail_bytes = (pagelist->offset + actual) &
- (drv_mgmt->info->cache_line_size - 1);
+ (cache_line_size - 1);

if ((actual >= 0) && (head_bytes != 0)) {
if (head_bytes > actual)
@@ -1707,8 +1710,8 @@ free_pagelist(struct vchiq_instance *instance, struct vchiq_pagelist_info *pagel
(tail_bytes != 0))
memcpy_to_page(pages[num_pages - 1],
(pagelist->offset + actual) &
- (PAGE_SIZE - 1) & ~(drv_mgmt->info->cache_line_size - 1),
- fragments + drv_mgmt->info->cache_line_size,
+ (PAGE_SIZE - 1) & ~(cache_line_size - 1),
+ fragments + cache_line_size,
tail_bytes);

down(&drv_mgmt->free_fragments_mutex);
--
2.45.2