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igb: cleanup IVAR configuration
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This change is meant to cleanup some of the IVAR register configuration.
igb_assign_vector had become pretty large with multiple copies of the same
general code for setting the IVAR. This change consolidates most of that
code by adding the igb_write_ivar function which allows us just to compute
the index and offset and then use that information to setup the IVAR.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Tested-by:  Aaron Brown  <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
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Alexander Duyck authored and Jeff Kirsher committed Oct 8, 2011
1 parent 0ba8299 commit 4be000c
Showing 1 changed file with 56 additions and 64 deletions.
120 changes: 56 additions & 64 deletions drivers/net/ethernet/intel/igb/igb_main.c
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Original file line number Diff line number Diff line change
Expand Up @@ -754,15 +754,40 @@ static int igb_alloc_queues(struct igb_adapter *adapter)
return -ENOMEM;
}

/**
* igb_write_ivar - configure ivar for given MSI-X vector
* @hw: pointer to the HW structure
* @msix_vector: vector number we are allocating to a given ring
* @index: row index of IVAR register to write within IVAR table
* @offset: column offset of in IVAR, should be multiple of 8
*
* This function is intended to handle the writing of the IVAR register
* for adapters 82576 and newer. The IVAR table consists of 2 columns,
* each containing an cause allocation for an Rx and Tx ring, and a
* variable number of rows depending on the number of queues supported.
**/
static void igb_write_ivar(struct e1000_hw *hw, int msix_vector,
int index, int offset)
{
u32 ivar = array_rd32(E1000_IVAR0, index);

/* clear any bits that are currently set */
ivar &= ~((u32)0xFF << offset);

/* write vector and valid bit */
ivar |= (msix_vector | E1000_IVAR_VALID) << offset;

array_wr32(E1000_IVAR0, index, ivar);
}

#define IGB_N0_QUEUE -1
static void igb_assign_vector(struct igb_q_vector *q_vector, int msix_vector)
{
u32 msixbm = 0;
struct igb_adapter *adapter = q_vector->adapter;
struct e1000_hw *hw = &adapter->hw;
u32 ivar, index;
int rx_queue = IGB_N0_QUEUE;
int tx_queue = IGB_N0_QUEUE;
u32 msixbm = 0;

if (q_vector->rx.ring)
rx_queue = q_vector->rx.ring->reg_idx;
Expand All @@ -785,72 +810,39 @@ static void igb_assign_vector(struct igb_q_vector *q_vector, int msix_vector)
q_vector->eims_value = msixbm;
break;
case e1000_82576:
/* 82576 uses a table-based method for assigning vectors.
Each queue has a single entry in the table to which we write
a vector number along with a "valid" bit. Sadly, the layout
of the table is somewhat counterintuitive. */
if (rx_queue > IGB_N0_QUEUE) {
index = (rx_queue & 0x7);
ivar = array_rd32(E1000_IVAR0, index);
if (rx_queue < 8) {
/* vector goes into low byte of register */
ivar = ivar & 0xFFFFFF00;
ivar |= msix_vector | E1000_IVAR_VALID;
} else {
/* vector goes into third byte of register */
ivar = ivar & 0xFF00FFFF;
ivar |= (msix_vector | E1000_IVAR_VALID) << 16;
}
array_wr32(E1000_IVAR0, index, ivar);
}
if (tx_queue > IGB_N0_QUEUE) {
index = (tx_queue & 0x7);
ivar = array_rd32(E1000_IVAR0, index);
if (tx_queue < 8) {
/* vector goes into second byte of register */
ivar = ivar & 0xFFFF00FF;
ivar |= (msix_vector | E1000_IVAR_VALID) << 8;
} else {
/* vector goes into high byte of register */
ivar = ivar & 0x00FFFFFF;
ivar |= (msix_vector | E1000_IVAR_VALID) << 24;
}
array_wr32(E1000_IVAR0, index, ivar);
}
/*
* 82576 uses a table that essentially consists of 2 columns
* with 8 rows. The ordering is column-major so we use the
* lower 3 bits as the row index, and the 4th bit as the
* column offset.
*/
if (rx_queue > IGB_N0_QUEUE)
igb_write_ivar(hw, msix_vector,
rx_queue & 0x7,
(rx_queue & 0x8) << 1);
if (tx_queue > IGB_N0_QUEUE)
igb_write_ivar(hw, msix_vector,
tx_queue & 0x7,
((tx_queue & 0x8) << 1) + 8);
q_vector->eims_value = 1 << msix_vector;
break;
case e1000_82580:
case e1000_i350:
/* 82580 uses the same table-based approach as 82576 but has fewer
entries as a result we carry over for queues greater than 4. */
if (rx_queue > IGB_N0_QUEUE) {
index = (rx_queue >> 1);
ivar = array_rd32(E1000_IVAR0, index);
if (rx_queue & 0x1) {
/* vector goes into third byte of register */
ivar = ivar & 0xFF00FFFF;
ivar |= (msix_vector | E1000_IVAR_VALID) << 16;
} else {
/* vector goes into low byte of register */
ivar = ivar & 0xFFFFFF00;
ivar |= msix_vector | E1000_IVAR_VALID;
}
array_wr32(E1000_IVAR0, index, ivar);
}
if (tx_queue > IGB_N0_QUEUE) {
index = (tx_queue >> 1);
ivar = array_rd32(E1000_IVAR0, index);
if (tx_queue & 0x1) {
/* vector goes into high byte of register */
ivar = ivar & 0x00FFFFFF;
ivar |= (msix_vector | E1000_IVAR_VALID) << 24;
} else {
/* vector goes into second byte of register */
ivar = ivar & 0xFFFF00FF;
ivar |= (msix_vector | E1000_IVAR_VALID) << 8;
}
array_wr32(E1000_IVAR0, index, ivar);
}
/*
* On 82580 and newer adapters the scheme is similar to 82576
* however instead of ordering column-major we have things
* ordered row-major. So we traverse the table by using
* bit 0 as the column offset, and the remaining bits as the
* row index.
*/
if (rx_queue > IGB_N0_QUEUE)
igb_write_ivar(hw, msix_vector,
rx_queue >> 1,
(rx_queue & 0x1) << 4);
if (tx_queue > IGB_N0_QUEUE)
igb_write_ivar(hw, msix_vector,
tx_queue >> 1,
((tx_queue & 0x1) << 4) + 8);
q_vector->eims_value = 1 << msix_vector;
break;
default:
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