igb: cleanup IVAR configuration
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>
diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c
index 8dc04e0..ec715f4 100644
--- a/drivers/net/ethernet/intel/igb/igb_main.c
+++ b/drivers/net/ethernet/intel/igb/igb_main.c
@@ -754,15 +754,40 @@
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;
@@ -785,72 +810,39 @@
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: