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Date: Fri, 27 Jan 2012 20:48:08 +0000
From: Ben Hutchings <bhutchings@...arflare.com>
To: David Miller <davem@...emloft.net>
CC: <netdev@...r.kernel.org>, <linux-net-drivers@...arflare.com>
Subject: [PATCH net-next 18/32] sfc: Correct interrupt timer quantum for
Siena (normal and turbo mode)
We currently assume that the timer quantum for Siena is 5 us, the same
as for Falcon. This is not correct; timer ticks are generated on a
rota which takes a minimum of 768 cycles (each event delivery or other
timer change will delay it by 3 cycles). The timer quantum should be
6.144 or 3.072 us depending on whether turbo mode is active.
Replace EFX_IRQ_MOD_RESOLUTION with a timer_quantum_ns field in struct
efx_nic, initialised by the efx_nic_type::probe function.
While we're at it, replace EFX_IRQ_MOD_MAX with a timer_period_max
field in struct efx_nic_type.
Signed-off-by: Ben Hutchings <bhutchings@...arflare.com>
---
drivers/net/ethernet/sfc/efx.c | 31 ++++++++++++++++++++++---------
drivers/net/ethernet/sfc/falcon.c | 6 ++++--
drivers/net/ethernet/sfc/net_driver.h | 4 ++++
drivers/net/ethernet/sfc/nic.h | 3 ---
drivers/net/ethernet/sfc/siena.c | 13 ++++++++++---
5 files changed, 40 insertions(+), 17 deletions(-)
diff --git a/drivers/net/ethernet/sfc/efx.c b/drivers/net/ethernet/sfc/efx.c
index de16247..9d4ab5e 100644
--- a/drivers/net/ethernet/sfc/efx.c
+++ b/drivers/net/ethernet/sfc/efx.c
@@ -1513,13 +1513,13 @@ static void efx_remove_all(struct efx_nic *efx)
*
**************************************************************************/
-static unsigned int irq_mod_ticks(unsigned int usecs, unsigned int resolution)
+static unsigned int irq_mod_ticks(unsigned int usecs, unsigned int quantum_ns)
{
if (usecs == 0)
return 0;
- if (usecs < resolution)
+ if (usecs * 1000 < quantum_ns)
return 1; /* never round down to 0 */
- return usecs / resolution;
+ return usecs * 1000 / quantum_ns;
}
/* Set interrupt moderation parameters */
@@ -1528,14 +1528,20 @@ int efx_init_irq_moderation(struct efx_nic *efx, unsigned int tx_usecs,
bool rx_may_override_tx)
{
struct efx_channel *channel;
- unsigned tx_ticks = irq_mod_ticks(tx_usecs, EFX_IRQ_MOD_RESOLUTION);
- unsigned rx_ticks = irq_mod_ticks(rx_usecs, EFX_IRQ_MOD_RESOLUTION);
+ unsigned int irq_mod_max = DIV_ROUND_UP(efx->type->timer_period_max *
+ efx->timer_quantum_ns,
+ 1000);
+ unsigned int tx_ticks;
+ unsigned int rx_ticks;
EFX_ASSERT_RESET_SERIALISED(efx);
- if (tx_ticks > EFX_IRQ_MOD_MAX || rx_ticks > EFX_IRQ_MOD_MAX)
+ if (tx_usecs > irq_mod_max || rx_usecs > irq_mod_max)
return -EINVAL;
+ tx_ticks = irq_mod_ticks(tx_usecs, efx->timer_quantum_ns);
+ rx_ticks = irq_mod_ticks(rx_usecs, efx->timer_quantum_ns);
+
if (tx_ticks != rx_ticks && efx->tx_channel_offset == 0 &&
!rx_may_override_tx) {
netif_err(efx, drv, efx->net_dev, "Channels are shared. "
@@ -1558,8 +1564,14 @@ int efx_init_irq_moderation(struct efx_nic *efx, unsigned int tx_usecs,
void efx_get_irq_moderation(struct efx_nic *efx, unsigned int *tx_usecs,
unsigned int *rx_usecs, bool *rx_adaptive)
{
+ /* We must round up when converting ticks to microseconds
+ * because we round down when converting the other way.
+ */
+
*rx_adaptive = efx->irq_rx_adaptive;
- *rx_usecs = efx->irq_rx_moderation * EFX_IRQ_MOD_RESOLUTION;
+ *rx_usecs = DIV_ROUND_UP(efx->irq_rx_moderation *
+ efx->timer_quantum_ns,
+ 1000);
/* If channels are shared between RX and TX, so is IRQ
* moderation. Otherwise, IRQ moderation is the same for all
@@ -1568,9 +1580,10 @@ void efx_get_irq_moderation(struct efx_nic *efx, unsigned int *tx_usecs,
if (efx->tx_channel_offset == 0)
*tx_usecs = *rx_usecs;
else
- *tx_usecs =
+ *tx_usecs = DIV_ROUND_UP(
efx->channel[efx->tx_channel_offset]->irq_moderation *
- EFX_IRQ_MOD_RESOLUTION;
+ efx->timer_quantum_ns,
+ 1000);
}
/**************************************************************************
diff --git a/drivers/net/ethernet/sfc/falcon.c b/drivers/net/ethernet/sfc/falcon.c
index fe21c7e..0b7880b 100644
--- a/drivers/net/ethernet/sfc/falcon.c
+++ b/drivers/net/ethernet/sfc/falcon.c
@@ -103,8 +103,6 @@ static void falcon_push_irq_moderation(struct efx_channel *channel)
efx_dword_t timer_cmd;
struct efx_nic *efx = channel->efx;
- BUILD_BUG_ON(EFX_IRQ_MOD_MAX > (1 << FRF_AB_TC_TIMER_VAL_WIDTH));
-
/* Set timer register */
if (channel->irq_moderation) {
EFX_POPULATE_DWORD_2(timer_cmd,
@@ -1471,6 +1469,8 @@ static int falcon_probe_nic(struct efx_nic *efx)
goto fail5;
}
+ efx->timer_quantum_ns = 4968; /* 621 cycles */
+
/* Initialise I2C adapter */
board = falcon_board(efx);
board->i2c_adap.owner = THIS_MODULE;
@@ -1785,6 +1785,7 @@ const struct efx_nic_type falcon_a1_nic_type = {
.rx_buffer_padding = 0x24,
.max_interrupt_mode = EFX_INT_MODE_MSI,
.phys_addr_channels = 4,
+ .timer_period_max = 1 << FRF_AB_TC_TIMER_VAL_WIDTH,
.tx_dc_base = 0x130000,
.rx_dc_base = 0x100000,
.offload_features = NETIF_F_IP_CSUM,
@@ -1836,6 +1837,7 @@ const struct efx_nic_type falcon_b0_nic_type = {
.phys_addr_channels = 32, /* Hardware limit is 64, but the legacy
* interrupt handler only supports 32
* channels */
+ .timer_period_max = 1 << FRF_AB_TC_TIMER_VAL_WIDTH,
.tx_dc_base = 0x130000,
.rx_dc_base = 0x100000,
.offload_features = NETIF_F_IP_CSUM | NETIF_F_RXHASH | NETIF_F_NTUPLE,
diff --git a/drivers/net/ethernet/sfc/net_driver.h b/drivers/net/ethernet/sfc/net_driver.h
index 4cbd997..8ce4d06 100644
--- a/drivers/net/ethernet/sfc/net_driver.h
+++ b/drivers/net/ethernet/sfc/net_driver.h
@@ -624,6 +624,7 @@ struct efx_filter_state;
* @membase_phys: Memory BAR value as physical address
* @membase: Memory BAR value
* @interrupt_mode: Interrupt mode
+ * @timer_quantum_ns: Interrupt timer quantum, in nanoseconds
* @irq_rx_adaptive: Adaptive IRQ moderation enabled for RX event queues
* @irq_rx_moderation: IRQ moderation time for RX event queues
* @msg_enable: Log message enable flags
@@ -706,6 +707,7 @@ struct efx_nic {
void __iomem *membase;
enum efx_int_mode interrupt_mode;
+ unsigned int timer_quantum_ns;
bool irq_rx_adaptive;
unsigned int irq_rx_moderation;
u32 msg_enable;
@@ -845,6 +847,7 @@ static inline unsigned int efx_port_num(struct efx_nic *efx)
* from &enum efx_init_mode.
* @phys_addr_channels: Number of channels with physically addressed
* descriptors
+ * @timer_period_max: Maximum period of interrupt timer (in ticks)
* @tx_dc_base: Base address in SRAM of TX queue descriptor caches
* @rx_dc_base: Base address in SRAM of RX queue descriptor caches
* @offload_features: net_device feature flags for protocol offload
@@ -889,6 +892,7 @@ struct efx_nic_type {
unsigned int rx_buffer_padding;
unsigned int max_interrupt_mode;
unsigned int phys_addr_channels;
+ unsigned int timer_period_max;
unsigned int tx_dc_base;
unsigned int rx_dc_base;
netdev_features_t offload_features;
diff --git a/drivers/net/ethernet/sfc/nic.h b/drivers/net/ethernet/sfc/nic.h
index cfda6de..a3ccd0b 100644
--- a/drivers/net/ethernet/sfc/nic.h
+++ b/drivers/net/ethernet/sfc/nic.h
@@ -205,9 +205,6 @@ extern irqreturn_t efx_nic_fatal_interrupt(struct efx_nic *efx);
extern irqreturn_t falcon_legacy_interrupt_a1(int irq, void *dev_id);
extern void falcon_irq_ack_a1(struct efx_nic *efx);
-#define EFX_IRQ_MOD_RESOLUTION 5
-#define EFX_IRQ_MOD_MAX 0x1000
-
/* Global Resources */
extern int efx_nic_flush_queues(struct efx_nic *efx);
extern void falcon_start_nic_stats(struct efx_nic *efx);
diff --git a/drivers/net/ethernet/sfc/siena.c b/drivers/net/ethernet/sfc/siena.c
index 65cb5e4..f054258 100644
--- a/drivers/net/ethernet/sfc/siena.c
+++ b/drivers/net/ethernet/sfc/siena.c
@@ -35,8 +35,6 @@ static void siena_push_irq_moderation(struct efx_channel *channel)
{
efx_dword_t timer_cmd;
- BUILD_BUG_ON(EFX_IRQ_MOD_MAX > (1 << FRF_CZ_TC_TIMER_VAL_WIDTH));
-
if (channel->irq_moderation)
EFX_POPULATE_DWORD_2(timer_cmd,
FRF_CZ_TC_TIMER_MODE,
@@ -216,7 +214,15 @@ static int siena_reset_hw(struct efx_nic *efx, enum reset_type method)
static int siena_probe_nvconfig(struct efx_nic *efx)
{
- return efx_mcdi_get_board_cfg(efx, efx->net_dev->perm_addr, NULL, NULL);
+ u32 caps = 0;
+ int rc;
+
+ rc = efx_mcdi_get_board_cfg(efx, efx->net_dev->perm_addr, NULL, &caps);
+
+ efx->timer_quantum_ns =
+ (caps & (1 << MC_CMD_CAPABILITIES_TURBO_ACTIVE_LBN)) ?
+ 3072 : 6144; /* 768 cycles */
+ return rc;
}
static int siena_probe_nic(struct efx_nic *efx)
@@ -644,6 +650,7 @@ const struct efx_nic_type siena_a0_nic_type = {
.phys_addr_channels = 32, /* Hardware limit is 64, but the legacy
* interrupt handler only supports 32
* channels */
+ .timer_period_max = 1 << FRF_CZ_TC_TIMER_VAL_WIDTH,
.tx_dc_base = 0x88000,
.rx_dc_base = 0x68000,
.offload_features = (NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM |
--
1.7.7.5
--
Ben Hutchings, Staff Engineer, Solarflare
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.
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