amd-xgbe: Simplify calculation and setting of queue fifos
The calculation of the Tx and Rx fifo sizes can be calculated rather
than hardcoded in a switch statement. Additionally, the per-queue fifo
sizes can be calculated rather than hardcoded using if/else if statements
that can possibly underutilize the available fifo area.
Change the code to calculate the fifo sizes and the per-queue fifo sizes
to simplify the code and make best use of the available fifo.
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/amd/xgbe/xgbe-dev.c b/drivers/net/ethernet/amd/xgbe/xgbe-dev.c
index 553e251..4551224 100644
--- a/drivers/net/ethernet/amd/xgbe/xgbe-dev.c
+++ b/drivers/net/ethernet/amd/xgbe/xgbe-dev.c
@@ -1940,84 +1940,31 @@
static unsigned int xgbe_calculate_per_queue_fifo(unsigned int fifo_size,
unsigned int queue_count)
{
- unsigned int q_fifo_size = 0;
- enum xgbe_mtl_fifo_size p_fifo = XGMAC_MTL_FIFO_SIZE_256;
+ unsigned int q_fifo_size;
+ unsigned int p_fifo;
- /* Calculate Tx/Rx fifo share per queue */
- switch (fifo_size) {
- case 0:
- q_fifo_size = XGBE_FIFO_SIZE_B(128);
- break;
- case 1:
- q_fifo_size = XGBE_FIFO_SIZE_B(256);
- break;
- case 2:
- q_fifo_size = XGBE_FIFO_SIZE_B(512);
- break;
- case 3:
- q_fifo_size = XGBE_FIFO_SIZE_KB(1);
- break;
- case 4:
- q_fifo_size = XGBE_FIFO_SIZE_KB(2);
- break;
- case 5:
- q_fifo_size = XGBE_FIFO_SIZE_KB(4);
- break;
- case 6:
- q_fifo_size = XGBE_FIFO_SIZE_KB(8);
- break;
- case 7:
- q_fifo_size = XGBE_FIFO_SIZE_KB(16);
- break;
- case 8:
- q_fifo_size = XGBE_FIFO_SIZE_KB(32);
- break;
- case 9:
- q_fifo_size = XGBE_FIFO_SIZE_KB(64);
- break;
- case 10:
- q_fifo_size = XGBE_FIFO_SIZE_KB(128);
- break;
- case 11:
- q_fifo_size = XGBE_FIFO_SIZE_KB(256);
- break;
- }
+ /* Calculate the configured fifo size */
+ q_fifo_size = 1 << (fifo_size + 7);
- /* The configured value is not the actual amount of fifo RAM */
+ /* The configured value may not be the actual amount of fifo RAM */
q_fifo_size = min_t(unsigned int, XGBE_FIFO_MAX, q_fifo_size);
q_fifo_size = q_fifo_size / queue_count;
- /* Set the queue fifo size programmable value */
- if (q_fifo_size >= XGBE_FIFO_SIZE_KB(256))
- p_fifo = XGMAC_MTL_FIFO_SIZE_256K;
- else if (q_fifo_size >= XGBE_FIFO_SIZE_KB(128))
- p_fifo = XGMAC_MTL_FIFO_SIZE_128K;
- else if (q_fifo_size >= XGBE_FIFO_SIZE_KB(64))
- p_fifo = XGMAC_MTL_FIFO_SIZE_64K;
- else if (q_fifo_size >= XGBE_FIFO_SIZE_KB(32))
- p_fifo = XGMAC_MTL_FIFO_SIZE_32K;
- else if (q_fifo_size >= XGBE_FIFO_SIZE_KB(16))
- p_fifo = XGMAC_MTL_FIFO_SIZE_16K;
- else if (q_fifo_size >= XGBE_FIFO_SIZE_KB(8))
- p_fifo = XGMAC_MTL_FIFO_SIZE_8K;
- else if (q_fifo_size >= XGBE_FIFO_SIZE_KB(4))
- p_fifo = XGMAC_MTL_FIFO_SIZE_4K;
- else if (q_fifo_size >= XGBE_FIFO_SIZE_KB(2))
- p_fifo = XGMAC_MTL_FIFO_SIZE_2K;
- else if (q_fifo_size >= XGBE_FIFO_SIZE_KB(1))
- p_fifo = XGMAC_MTL_FIFO_SIZE_1K;
- else if (q_fifo_size >= XGBE_FIFO_SIZE_B(512))
- p_fifo = XGMAC_MTL_FIFO_SIZE_512;
- else if (q_fifo_size >= XGBE_FIFO_SIZE_B(256))
- p_fifo = XGMAC_MTL_FIFO_SIZE_256;
+ /* Each increment in the queue fifo size represents 256 bytes of
+ * fifo, with 0 representing 256 bytes. Distribute the fifo equally
+ * between the queues.
+ */
+ p_fifo = q_fifo_size / 256;
+ if (p_fifo)
+ p_fifo--;
return p_fifo;
}
static void xgbe_config_tx_fifo_size(struct xgbe_prv_data *pdata)
{
- enum xgbe_mtl_fifo_size fifo_size;
+ unsigned int fifo_size;
unsigned int i;
fifo_size = xgbe_calculate_per_queue_fifo(pdata->hw_feat.tx_fifo_size,
@@ -2033,7 +1980,7 @@
static void xgbe_config_rx_fifo_size(struct xgbe_prv_data *pdata)
{
- enum xgbe_mtl_fifo_size fifo_size;
+ unsigned int fifo_size;
unsigned int i;
fifo_size = xgbe_calculate_per_queue_fifo(pdata->hw_feat.rx_fifo_size,