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igb: change the head and tail offsets into pointers

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Since we are writting to the head/tail pointers frequently we might as well
save ourselves some processing time by converting the head and tail offsets
directly to pointers.  This will shave a few cycles off the rx/tx path and
allows us to move one step closer to the rings being a bit more independant of
each other.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Alexander Duyck
2009-10-27 15:51:27 +00:00
committed by David S. Miller
parent 952f72a8ce
commit fce99e3415
2 changed files with 18 additions and 18 deletions
Download Patch File Download Diff File Expand all files Collapse all files

4
drivers/net/igb/igb.h
View File

@@ -178,8 +178,8 @@ struct igb_ring {
unsigned int count; /* number of desc. in the ring */ unsigned int count; /* number of desc. in the ring */
u16 next_to_use; u16 next_to_use;
u16 next_to_clean; u16 next_to_clean;
u16 head; void __iomem *head;
u16 tail; void __iomem *tail;
struct igb_buffer *buffer_info; /* array of buffer info structs */ struct igb_buffer *buffer_info; /* array of buffer info structs */
u8 queue_index; u8 queue_index;

32
drivers/net/igb/igb_main.c
View File

@@ -2124,10 +2124,10 @@ static void igb_configure_tx_ring(struct igb_adapter *adapter,
tdba & 0x00000000ffffffffULL); tdba & 0x00000000ffffffffULL);
wr32(E1000_TDBAH(reg_idx), tdba >> 32); wr32(E1000_TDBAH(reg_idx), tdba >> 32);
ring->head = E1000_TDH(reg_idx); ring->head = hw->hw_addr + E1000_TDH(reg_idx);
ring->tail = E1000_TDT(reg_idx); ring->tail = hw->hw_addr + E1000_TDT(reg_idx);
writel(0, hw->hw_addr + ring->tail); writel(0, ring->head);
writel(0, hw->hw_addr + ring->head); writel(0, ring->tail);
txdctl |= IGB_TX_PTHRESH; txdctl |= IGB_TX_PTHRESH;
txdctl |= IGB_TX_HTHRESH << 8; txdctl |= IGB_TX_HTHRESH << 8;
@@ -2354,10 +2354,10 @@ static void igb_configure_rx_ring(struct igb_adapter *adapter,
ring->count * sizeof(union e1000_adv_rx_desc)); ring->count * sizeof(union e1000_adv_rx_desc));
/* initialize head and tail */ /* initialize head and tail */
ring->head = E1000_RDH(reg_idx); ring->head = hw->hw_addr + E1000_RDH(reg_idx);
ring->tail = E1000_RDT(reg_idx); ring->tail = hw->hw_addr + E1000_RDT(reg_idx);
writel(0, hw->hw_addr + ring->head); writel(0, ring->head);
writel(0, hw->hw_addr + ring->tail); writel(0, ring->tail);
/* set descriptor configuration */ /* set descriptor configuration */
if (adapter->rx_buffer_len < IGB_RXBUFFER_1024) { if (adapter->rx_buffer_len < IGB_RXBUFFER_1024) {
@@ -2567,8 +2567,8 @@ static void igb_clean_tx_ring(struct igb_ring *tx_ring)
tx_ring->next_to_use = 0; tx_ring->next_to_use = 0;
tx_ring->next_to_clean = 0; tx_ring->next_to_clean = 0;
writel(0, adapter->hw.hw_addr + tx_ring->head); writel(0, tx_ring->head);
writel(0, adapter->hw.hw_addr + tx_ring->tail); writel(0, tx_ring->tail);
} }
/** /**
@@ -2667,8 +2667,8 @@ static void igb_clean_rx_ring(struct igb_ring *rx_ring)
rx_ring->next_to_clean = 0; rx_ring->next_to_clean = 0;
rx_ring->next_to_use = 0; rx_ring->next_to_use = 0;
writel(0, adapter->hw.hw_addr + rx_ring->head); writel(0, rx_ring->head);
writel(0, adapter->hw.hw_addr + rx_ring->tail); writel(0, rx_ring->tail);
} }
/** /**
@@ -3556,7 +3556,7 @@ static inline void igb_tx_queue_adv(struct igb_adapter *adapter,
wmb(); wmb();
tx_ring->next_to_use = i; tx_ring->next_to_use = i;
writel(i, adapter->hw.hw_addr + tx_ring->tail); writel(i, tx_ring->tail);
/* we need this if more than one processor can write to our tail /* we need this if more than one processor can write to our tail
* at a time, it syncronizes IO on IA64/Altix systems */ * at a time, it syncronizes IO on IA64/Altix systems */
mmiowb(); mmiowb();
@@ -4761,8 +4761,8 @@ static bool igb_clean_tx_irq(struct igb_q_vector *q_vector)
" jiffies <%lx>\n" " jiffies <%lx>\n"
" desc.status <%x>\n", " desc.status <%x>\n",
tx_ring->queue_index, tx_ring->queue_index,
readl(adapter->hw.hw_addr + tx_ring->head), readl(tx_ring->head),
readl(adapter->hw.hw_addr + tx_ring->tail), readl(tx_ring->tail),
tx_ring->next_to_use, tx_ring->next_to_use,
tx_ring->next_to_clean, tx_ring->next_to_clean,
tx_ring->buffer_info[i].time_stamp, tx_ring->buffer_info[i].time_stamp,
@@ -5103,7 +5103,7 @@ no_buffers:
* applicable for weak-ordered memory model archs, * applicable for weak-ordered memory model archs,
* such as IA-64). */ * such as IA-64). */
wmb(); wmb();
writel(i, adapter->hw.hw_addr + rx_ring->tail); writel(i, rx_ring->tail);
} }
} }