[PATCH v1 1/1] media: c8sectpfe: Clean up handling of *_buffer_aligned

From: Andy Shevchenko
Date: Wed Feb 09 2022 - 13:37:28 EST


There are a few cases where code is harder than needed to read.
Improve those by:
- dropping unnecessary castings (see note below)
- use PTR_ALING() to be more explicit on what's going on there
- use proper definitions instead of hard coded values

Note, dropping castings will allow to perform an additional check
that type is not changed from void * to something else, e.g. u64,
which may very well break the bitmap APIs.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
---
.../platform/sti/c8sectpfe/c8sectpfe-core.c | 30 +++++++------------
1 file changed, 11 insertions(+), 19 deletions(-)

diff --git a/drivers/media/platform/sti/c8sectpfe/c8sectpfe-core.c b/drivers/media/platform/sti/c8sectpfe/c8sectpfe-core.c
index 7bb1384e4bad..d60908ec9ea7 100644
--- a/drivers/media/platform/sti/c8sectpfe/c8sectpfe-core.c
+++ b/drivers/media/platform/sti/c8sectpfe/c8sectpfe-core.c
@@ -107,7 +107,7 @@ static void channel_swdemux_tsklet(struct tasklet_struct *t)
size,
DMA_FROM_DEVICE);

- buf = (u8 *) channel->back_buffer_aligned;
+ buf = channel->back_buffer_aligned;

dev_dbg(fei->dev,
"chan=%d channel=%p num_packets = %d, buf = %p, pos = 0x%x\n\trp=0x%lx, wp=0x%lx\n",
@@ -176,7 +176,7 @@ static int c8sectpfe_start_feed(struct dvb_demux_feed *dvbdmxfeed)

channel = fei->channel_data[stdemux->tsin_index];

- bitmap = (unsigned long *) channel->pid_buffer_aligned;
+ bitmap = channel->pid_buffer_aligned;

/* 8192 is a special PID */
if (dvbdmxfeed->pid == 8192) {
@@ -272,7 +272,7 @@ static int c8sectpfe_stop_feed(struct dvb_demux_feed *dvbdmxfeed)

channel = fei->channel_data[stdemux->tsin_index];

- bitmap = (unsigned long *) channel->pid_buffer_aligned;
+ bitmap = channel->pid_buffer_aligned;

if (dvbdmxfeed->pid == 8192) {
tmp = readl(fei->io + C8SECTPFE_IB_PID_SET(channel->tsin_id));
@@ -333,8 +333,7 @@ static int c8sectpfe_stop_feed(struct dvb_demux_feed *dvbdmxfeed)
__func__, __LINE__, stdemux, channel->tsin_id);

/* turn off all PIDS in the bitmap */
- memset((void *)channel->pid_buffer_aligned
- , 0x00, PID_TABLE_SIZE);
+ memset(channel->pid_buffer_aligned, 0, PID_TABLE_SIZE);

/* manage cache so data is visible to HW */
dma_sync_single_for_device(fei->dev,
@@ -458,23 +457,19 @@ static int configure_memdma_and_inputblock(struct c8sectpfei *fei,

init_completion(&tsin->idle_completion);

- tsin->back_buffer_start = kzalloc(FEI_BUFFER_SIZE +
- FEI_ALIGNMENT, GFP_KERNEL);
-
+ tsin->back_buffer_start = kzalloc(FEI_BUFFER_SIZE + FEI_ALIGNMENT, GFP_KERNEL);
if (!tsin->back_buffer_start) {
ret = -ENOMEM;
goto err_unmap;
}

/* Ensure backbuffer is 32byte aligned */
- tsin->back_buffer_aligned = tsin->back_buffer_start
- + FEI_ALIGNMENT;
+ tsin->back_buffer_aligned = tsin->back_buffer_start + FEI_ALIGNMENT;

- tsin->back_buffer_aligned = (void *)
- (((uintptr_t) tsin->back_buffer_aligned) & ~0x1F);
+ tsin->back_buffer_aligned = PTR_ALIGN(tsin->back_buffer_aligned, FEI_ALIGNMENT);

tsin->back_buffer_busaddr = dma_map_single(fei->dev,
- (void *)tsin->back_buffer_aligned,
+ tsin->back_buffer_aligned,
FEI_BUFFER_SIZE,
DMA_BIDIRECTIONAL);

@@ -489,8 +484,7 @@ static int configure_memdma_and_inputblock(struct c8sectpfei *fei,
* per pid. By powers of deduction we conclude stih407 family
* is configured (at SoC design stage) for bit per pid.
*/
- tsin->pid_buffer_start = kzalloc(2048, GFP_KERNEL);
-
+ tsin->pid_buffer_start = kzalloc(PID_TABLE_SIZE + PID_TABLE_SIZE, GFP_KERNEL);
if (!tsin->pid_buffer_start) {
ret = -ENOMEM;
goto err_unmap;
@@ -503,11 +497,9 @@ static int configure_memdma_and_inputblock(struct c8sectpfei *fei,
* the register.
*/

- tsin->pid_buffer_aligned = tsin->pid_buffer_start +
- PID_TABLE_SIZE;
+ tsin->pid_buffer_aligned = tsin->pid_buffer_start + PID_TABLE_SIZE;

- tsin->pid_buffer_aligned = (void *)
- (((uintptr_t) tsin->pid_buffer_aligned) & ~0x3ff);
+ tsin->pid_buffer_aligned = PTR_ALIGN(tsin->pid_buffer_aligned, PID_TABLE_SIZE);

tsin->pid_buffer_busaddr = dma_map_single(fei->dev,
tsin->pid_buffer_aligned,
--
2.34.1