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staging: et131x: Remove unnecessary DMA address alignment code
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"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@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Mark Einon authored and Greg Kroah-Hartman committed Nov 13, 2012
1 parent 8764893 commit d3c75e8
Showing 1 changed file with 5 additions and 67 deletions.
72 changes: 5 additions & 67 deletions drivers/staging/et131x/et131x.c
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Original file line number Diff line number Diff line change
Expand Up @@ -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;
Expand Down Expand Up @@ -2226,32 +2225,6 @@ static inline u32 bump_free_buff_ring(u32 *free_buff_ring, u32 limit)
return tmp_free_buff_ring;
}

/**
* 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
Expand All @@ -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 */
Expand Down Expand Up @@ -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
Expand All @@ -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;

Expand All @@ -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
Expand Down Expand Up @@ -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,
Expand All @@ -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;
Expand Down Expand Up @@ -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,
Expand Down Expand Up @@ -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,
Expand Down

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