[PATCH 2/2] staging: et131x: Remove unnecessary DMA address alignment code
From: Mark Einon
Date: Mon Nov 12 2012 - 16:16:26 EST
>From Documentation/DMA-API-HOWTO.txt on dma_alloc_coherent():
"The cpu return address and the DMA bus master address are both
guaranteed to be aligned to the smallest PAGE_SIZE order which
is greater than or equal to the requested size."
There are several places in the et131x.c code where these addresses are
aligned to a 4k boundary after a call to dma_alloc_coherent(),
needlessly.
Remove these alignment offset calculations, and the
et131x_align_allocated_memory() call which is only used for 4k
alignments.
Signed-off-by: Mark Einon <mark.einon@xxxxxxxxx>
---
drivers/staging/et131x/et131x.c | 72 +++------------------------------------
1 file changed, 5 insertions(+), 67 deletions(-)
diff --git a/drivers/staging/et131x/et131x.c b/drivers/staging/et131x/et131x.c
index 4f68646..5f15a2e 100644
--- a/drivers/staging/et131x/et131x.c
+++ b/drivers/staging/et131x/et131x.c
@@ -290,7 +290,6 @@ struct fbr_lookup {
dma_addr_t ring_physaddr;
void *mem_virtaddrs[MAX_DESC_PER_RING_RX / FBR_CHUNKS];
dma_addr_t mem_physaddrs[MAX_DESC_PER_RING_RX / FBR_CHUNKS];
- dma_addr_t offset;
u32 local_full;
u32 num_entries;
dma_addr_t buffsize;
@@ -2227,32 +2226,6 @@ static inline u32 bump_free_buff_ring(u32 *free_buff_ring, u32 limit)
}
/**
- * et131x_align_allocated_memory - Align allocated memory on a given boundary
- * @adapter: pointer to our adapter structure
- * @phys_addr: pointer to Physical address
- * @offset: pointer to the offset variable
- * @mask: correct mask
- */
-static void et131x_align_allocated_memory(struct et131x_adapter *adapter,
- dma_addr_t *phys_addr,
- dma_addr_t *offset,
- u64 mask)
-{
- u64 new_addr = *phys_addr & ~mask;
-
- *offset = 0;
-
- if (new_addr != *phys_addr) {
- /* Move to next aligned block */
- new_addr += mask + 1;
- /* Return offset for adjusting virt addr */
- *offset = new_addr - *phys_addr;
- /* Return new physical address */
- *phys_addr = new_addr;
- }
-}
-
-/**
* et131x_rx_dma_memory_alloc
* @adapter: pointer to our private adapter structure
*
@@ -2268,7 +2241,6 @@ static int et131x_rx_dma_memory_alloc(struct et131x_adapter *adapter)
u32 bufsize;
u32 pktstat_ringsize;
u32 fbr_chunksize;
- u32 fbr_align;
struct rx_ring *rx_ring;
/* Setup some convenience pointers */
@@ -2331,29 +2303,13 @@ static int et131x_rx_dma_memory_alloc(struct et131x_adapter *adapter)
"Cannot alloc memory for Free Buffer Ring %d\n", id);
return -ENOMEM;
}
-
- /* Align Free Buffer Ring on a 4K boundary */
- et131x_align_allocated_memory(adapter,
- &rx_ring->fbr[id]->ring_physaddr,
- &rx_ring->fbr[id]->offset, 0x0FFF);
-
- rx_ring->fbr[id]->ring_virtaddr =
- (void *)((u8 *) rx_ring->fbr[id]->ring_virtaddr +
- rx_ring->fbr[id]->offset);
}
for (id = 0; id < NUM_FBRS; id++) {
- if (id == 0 && rx_ring->fbr[id]->buffsize > 4096)
- fbr_align = 4096;
- else
- fbr_align = rx_ring->fbr[id]->buffsize;
-
- fbr_chunksize = (FBR_CHUNKS *
- rx_ring->fbr[id]->buffsize) + fbr_align - 1;
+ fbr_chunksize = (FBR_CHUNKS * rx_ring->fbr[id]->buffsize);
for (i = 0; i < (rx_ring->fbr[id]->num_entries / FBR_CHUNKS); i++) {
dma_addr_t fbr_tmp_physaddr;
- dma_addr_t fbr_offset;
/* This code allocates an area of memory big enough for
* N free buffers + (buffer_size - 1) so that the
@@ -2376,11 +2332,6 @@ static int et131x_rx_dma_memory_alloc(struct et131x_adapter *adapter)
/* See NOTE in "Save Physical Address" comment above */
fbr_tmp_physaddr = rx_ring->fbr[id]->mem_physaddrs[i];
- et131x_align_allocated_memory(adapter,
- &fbr_tmp_physaddr,
- &fbr_offset,
- (fbr_align - 1));
-
for (j = 0; j < FBR_CHUNKS; j++) {
u32 index = (i * FBR_CHUNKS) + j;
@@ -2389,7 +2340,7 @@ static int et131x_rx_dma_memory_alloc(struct et131x_adapter *adapter)
*/
rx_ring->fbr[id]->virt[index] =
(u8 *) rx_ring->fbr[id]->mem_virtaddrs[i] +
- (j * rx_ring->fbr[id]->buffsize) + fbr_offset;
+ (j * rx_ring->fbr[id]->buffsize);
/* now store the physical address in the
* descriptor so the device can access it
@@ -2499,16 +2450,8 @@ static void et131x_rx_dma_memory_free(struct et131x_adapter *adapter)
(rx_ring->fbr[id]->num_entries / FBR_CHUNKS);
index++) {
if (rx_ring->fbr[id]->mem_virtaddrs[index]) {
- u32 fbr_align;
- if (rx_ring->fbr[id]->buffsize > 4096)
- fbr_align = 4096;
- else
- fbr_align = rx_ring->fbr[id]->buffsize;
-
- bufsize =
- (rx_ring->fbr[id]->buffsize * FBR_CHUNKS) +
- fbr_align - 1;
+ bufsize = (rx_ring->fbr[id]->buffsize * FBR_CHUNKS);
dma_free_coherent(&adapter->pdev->dev,
bufsize,
@@ -2519,10 +2462,6 @@ static void et131x_rx_dma_memory_free(struct et131x_adapter *adapter)
}
}
- /* Now the FIFO itself */
- rx_ring->fbr[id]->ring_virtaddr = (void *)((u8 *)
- rx_ring->fbr[id]->ring_virtaddr - rx_ring->fbr[id]->offset);
-
bufsize =
(sizeof(struct fbr_desc) * rx_ring->fbr[id]->num_entries) +
0xfff;
@@ -2967,7 +2906,7 @@ static int et131x_tx_dma_memory_alloc(struct et131x_adapter *adapter)
/* Allocate enough memory for the Tx descriptor ring, and allocate
* some extra so that the ring can be aligned on a 4k boundary.
*/
- desc_size = (sizeof(struct tx_desc) * NUM_DESC_PER_RING_TX) + 4096 - 1;
+ desc_size = (sizeof(struct tx_desc) * NUM_DESC_PER_RING_TX);
tx_ring->tx_desc_ring =
(struct tx_desc *) dma_alloc_coherent(&adapter->pdev->dev,
desc_size,
@@ -3011,8 +2950,7 @@ static void et131x_tx_dma_memory_free(struct et131x_adapter *adapter)
if (adapter->tx_ring.tx_desc_ring) {
/* Free memory relating to Tx rings here */
- desc_size = (sizeof(struct tx_desc) * NUM_DESC_PER_RING_TX)
- + 4096 - 1;
+ desc_size = (sizeof(struct tx_desc) * NUM_DESC_PER_RING_TX);
dma_free_coherent(&adapter->pdev->dev,
desc_size,
adapter->tx_ring.tx_desc_ring,
--
1.7.9.5
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