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Add facilities for tuning the "em" driver's interrupt delays without

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recompiling the driver.  See the comments near the top of "if_em.h"
for descriptions of these delays.  Four new loader tunables control
the system-wide default values:

    hw.em.tx_int_delay
    hw.em.rx_int_delay
    hw.em.tx_abs_int_delay
    hw.em.rx_abs_int_delay

The tunables are specified in microseconds.  The valid range is
0-67108 usec., and 0 means that the timer is disabled.

There are also four new sysctls (actually, a set of four for each
"em" device in the system) to query and change the interrupt delays
after the system is up:

    hw.em0.tx_int_delay
    hw.em0.rx_int_delay
    hw.em0.tx_abs_int_delay (not present for 82542/3/4 adapters)
    hw.em0.rx_abs_int_delay (not present for 82542/3/4 adapters)

It seems to be OK to change these values even while the adapter is
passing traffic.

Approved by:	Prafulla Deuskar <pdeuskar@FreeBSD.ORG>
MFC after:	4 weeks
This commit is contained in:
John Polstra 2003-08-01 17:33:59 +00:00
parent 1d324ddef8
commit 515d4440fe
3 changed files with 143 additions and 39 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

117
sys/dev/em/if_em.c
View File

@ -163,6 +163,10 @@ static void em_print_debug_info(struct adapter *);
static int em_is_valid_ether_addr(u_int8_t *); static int em_is_valid_ether_addr(u_int8_t *);
static int em_sysctl_stats(SYSCTL_HANDLER_ARGS); static int em_sysctl_stats(SYSCTL_HANDLER_ARGS);
static int em_sysctl_debug_info(SYSCTL_HANDLER_ARGS); static int em_sysctl_debug_info(SYSCTL_HANDLER_ARGS);
static int em_sysctl_int_delay(SYSCTL_HANDLER_ARGS);
static void em_add_int_delay_sysctl(struct adapter *, const char *,
const char *, struct em_int_delay_info *,
int, int);
/********************************************************************* /*********************************************************************
* FreeBSD Device Interface Entry Points * FreeBSD Device Interface Entry Points
@ -186,6 +190,23 @@ DRIVER_MODULE(em, pci, em_driver, em_devclass, 0, 0);
MODULE_DEPEND(em, pci, 1, 1, 1); MODULE_DEPEND(em, pci, 1, 1, 1);
MODULE_DEPEND(em, ether, 1, 1, 1); MODULE_DEPEND(em, ether, 1, 1, 1);
/*********************************************************************
* Tunable default values.
*********************************************************************/
#define E1000_TICKS_TO_USECS(ticks) ((1024 * (ticks) + 500) / 1000)
#define E1000_USECS_TO_TICKS(usecs) ((1000 * (usecs) + 512) / 1024)
static int em_tx_int_delay_dflt = E1000_TICKS_TO_USECS(EM_TIDV);
static int em_rx_int_delay_dflt = E1000_TICKS_TO_USECS(EM_RDTR);
static int em_tx_abs_int_delay_dflt = E1000_TICKS_TO_USECS(EM_TADV);
static int em_rx_abs_int_delay_dflt = E1000_TICKS_TO_USECS(EM_RADV);
TUNABLE_INT("hw.em.tx_int_delay", &em_tx_int_delay_dflt);
TUNABLE_INT("hw.em.rx_int_delay", &em_rx_int_delay_dflt);
TUNABLE_INT("hw.em.tx_abs_int_delay", &em_tx_abs_int_delay_dflt);
TUNABLE_INT("hw.em.rx_abs_int_delay", &em_rx_abs_int_delay_dflt);
/********************************************************************* /*********************************************************************
* Device identification routine * Device identification routine
* *
@ -305,14 +326,30 @@ em_attach(device_t dev)
/* Determine hardware revision */ /* Determine hardware revision */
em_identify_hardware(adapter); em_identify_hardware(adapter);
/* Set up some sysctls for the tunable interrupt delays */
em_add_int_delay_sysctl(adapter, "rx_int_delay",
"receive interrupt delay in usecs", &adapter->rx_int_delay,
E1000_REG_OFFSET(&adapter->hw, RDTR), em_rx_int_delay_dflt);
em_add_int_delay_sysctl(adapter, "tx_int_delay",
"transmit interrupt delay in usecs", &adapter->tx_int_delay,
E1000_REG_OFFSET(&adapter->hw, TIDV), em_tx_int_delay_dflt);
if (adapter->hw.mac_type >= em_82540) {
em_add_int_delay_sysctl(adapter, "rx_abs_int_delay",
"receive interrupt delay limit in usecs",
&adapter->rx_abs_int_delay,
E1000_REG_OFFSET(&adapter->hw, RADV),
em_rx_abs_int_delay_dflt);
em_add_int_delay_sysctl(adapter, "tx_abs_int_delay",
"transmit interrupt delay limit in usecs",
&adapter->tx_abs_int_delay,
E1000_REG_OFFSET(&adapter->hw, TADV),
em_tx_abs_int_delay_dflt);
}
/* Parameters (to be read from user) */ /* Parameters (to be read from user) */
adapter->num_tx_desc = EM_MAX_TXD; adapter->num_tx_desc = EM_MAX_TXD;
adapter->num_rx_desc = EM_MAX_RXD; adapter->num_rx_desc = EM_MAX_RXD;
adapter->tx_int_delay = EM_TIDV;
adapter->tx_abs_int_delay = EM_TADV;
adapter->rx_int_delay = EM_RDTR;
adapter->rx_abs_int_delay = EM_RADV;
adapter->hw.autoneg = DO_AUTO_NEG; adapter->hw.autoneg = DO_AUTO_NEG;
adapter->hw.wait_autoneg_complete = WAIT_FOR_AUTO_NEG_DEFAULT; adapter->hw.wait_autoneg_complete = WAIT_FOR_AUTO_NEG_DEFAULT;
adapter->hw.autoneg_advertised = AUTONEG_ADV_DEFAULT; adapter->hw.autoneg_advertised = AUTONEG_ADV_DEFAULT;
@ -1982,9 +2019,10 @@ em_initialize_transmit_unit(struct adapter * adapter)
} }
E1000_WRITE_REG(&adapter->hw, TIPG, reg_tipg); E1000_WRITE_REG(&adapter->hw, TIPG, reg_tipg);
E1000_WRITE_REG(&adapter->hw, TIDV, adapter->tx_int_delay); E1000_WRITE_REG(&adapter->hw, TIDV, adapter->tx_int_delay.value);
if(adapter->hw.mac_type >= em_82540) if(adapter->hw.mac_type >= em_82540)
E1000_WRITE_REG(&adapter->hw, TADV, adapter->tx_abs_int_delay); E1000_WRITE_REG(&adapter->hw, TADV,
adapter->tx_abs_int_delay.value);
/* Program the Transmit Control Register */ /* Program the Transmit Control Register */
reg_tctl = E1000_TCTL_PSP | E1000_TCTL_EN | reg_tctl = E1000_TCTL_PSP | E1000_TCTL_EN |
@ -1999,7 +2037,7 @@ em_initialize_transmit_unit(struct adapter * adapter)
/* Setup Transmit Descriptor Settings for this adapter */ /* Setup Transmit Descriptor Settings for this adapter */
adapter->txd_cmd = E1000_TXD_CMD_IFCS | E1000_TXD_CMD_RS; adapter->txd_cmd = E1000_TXD_CMD_IFCS | E1000_TXD_CMD_RS;
if (adapter->tx_int_delay > 0) if (adapter->tx_int_delay.value > 0)
adapter->txd_cmd |= E1000_TXD_CMD_IDE; adapter->txd_cmd |= E1000_TXD_CMD_IDE;
return; return;
@ -2368,10 +2406,11 @@ em_initialize_receive_unit(struct adapter * adapter)
/* Set the Receive Delay Timer Register */ /* Set the Receive Delay Timer Register */
E1000_WRITE_REG(&adapter->hw, RDTR, E1000_WRITE_REG(&adapter->hw, RDTR,
adapter->rx_int_delay | E1000_RDT_FPDB); adapter->rx_int_delay.value | E1000_RDT_FPDB);
if(adapter->hw.mac_type >= em_82540) { if(adapter->hw.mac_type >= em_82540) {
E1000_WRITE_REG(&adapter->hw, RADV, adapter->rx_abs_int_delay); E1000_WRITE_REG(&adapter->hw, RADV,
adapter->rx_abs_int_delay.value);
/* Set the interrupt throttling rate. Value is calculated /* Set the interrupt throttling rate. Value is calculated
* as DEFAULT_ITR = 1/(MAX_INTS_PER_SEC * 256ns) */ * as DEFAULT_ITR = 1/(MAX_INTS_PER_SEC * 256ns) */
@ -2999,3 +3038,63 @@ em_sysctl_stats(SYSCTL_HANDLER_ARGS)
return error; return error;
} }
static int
em_sysctl_int_delay(SYSCTL_HANDLER_ARGS)
{
struct em_int_delay_info *info;
struct adapter *adapter;
u_int32_t regval;
int error;
int usecs;
int ticks;
int s;
info = (struct em_int_delay_info *)arg1;
adapter = info->adapter;
usecs = info->value;
error = sysctl_handle_int(oidp, &usecs, 0, req);
if (error != 0 || req->newptr == NULL)
return error;
if (usecs < 0 || usecs > E1000_TICKS_TO_USECS(65535))
return EINVAL;
info->value = usecs;
ticks = E1000_USECS_TO_TICKS(usecs);
s = splimp();
regval = E1000_READ_OFFSET(&adapter->hw, info->offset);
regval = (regval & ~0xffff) | (ticks & 0xffff);
/* Handle a few special cases. */
switch (info->offset) {
case E1000_RDTR:
case E1000_82542_RDTR:
regval |= E1000_RDT_FPDB;
break;
case E1000_TIDV:
case E1000_82542_TIDV:
if (ticks == 0) {
adapter->txd_cmd &= ~E1000_TXD_CMD_IDE;
/* Don't write 0 into the TIDV register. */
regval++;
} else
adapter->txd_cmd |= E1000_TXD_CMD_IDE;
break;
}
E1000_WRITE_OFFSET(&adapter->hw, info->offset, regval);
splx(s);
return 0;
}
static void
em_add_int_delay_sysctl(struct adapter *adapter, const char *name,
const char *description, struct em_int_delay_info *info,
int offset, int value)
{
info->adapter = adapter;
info->offset = offset;
info->value = value;
SYSCTL_ADD_PROC(&adapter->sysctl_ctx,
SYSCTL_CHILDREN(adapter->sysctl_tree),
OID_AUTO, name, CTLTYPE_INT|CTLFLAG_RW,
info, 0, em_sysctl_int_delay, "I", description);
}

15
sys/dev/em/if_em.h
View File

@ -294,6 +294,13 @@ typedef enum _XSUM_CONTEXT_T {
OFFLOAD_UDP_IP OFFLOAD_UDP_IP
} XSUM_CONTEXT_T; } XSUM_CONTEXT_T;
struct adapter;
struct em_int_delay_info {
struct adapter *adapter; /* Back-pointer to the adapter struct */
int offset; /* Register offset to read/write */
int value; /* Current value in usecs */
};
/* Our adapter structure */ /* Our adapter structure */
struct adapter { struct adapter {
struct arpcom interface_data; struct arpcom interface_data;
@ -320,10 +327,10 @@ struct adapter {
u_int16_t link_speed; u_int16_t link_speed;
u_int16_t link_duplex; u_int16_t link_duplex;
u_int32_t smartspeed; u_int32_t smartspeed;
u_int32_t tx_int_delay; struct em_int_delay_info tx_int_delay;
u_int32_t tx_abs_int_delay; struct em_int_delay_info tx_abs_int_delay;
u_int32_t rx_int_delay; struct em_int_delay_info rx_int_delay;
u_int32_t rx_abs_int_delay; struct em_int_delay_info rx_abs_int_delay;
XSUM_CONTEXT_T active_checksum_context; XSUM_CONTEXT_T active_checksum_context;

50
sys/dev/em/if_em_osdep.h
View File

@ -89,38 +89,36 @@ struct em_osdep
struct device *dev; struct device *dev;
}; };
#define E1000_WRITE_FLUSH(a) E1000_READ_REG(a, STATUS) #define E1000_WRITE_FLUSH(hw) E1000_READ_REG(hw, STATUS)
#define E1000_READ_REG(a, reg) (\ /* Read from an absolute offset in the adapter's memory space */
bus_space_read_4( ((struct em_osdep *)(a)->back)->mem_bus_space_tag, \ #define E1000_READ_OFFSET(hw, offset) \
((struct em_osdep *)(a)->back)->mem_bus_space_handle, \ bus_space_read_4( ((struct em_osdep *)(hw)->back)->mem_bus_space_tag, \
((a)->mac_type >= em_82543) ? E1000_##reg : E1000_82542_##reg)) ((struct em_osdep *)(hw)->back)->mem_bus_space_handle, \
offset)
#define E1000_WRITE_REG(a, reg, value) (\ /* Write to an absolute offset in the adapter's memory space */
bus_space_write_4( ((struct em_osdep *)(a)->back)->mem_bus_space_tag, \ #define E1000_WRITE_OFFSET(hw, offset, value) \
((struct em_osdep *)(a)->back)->mem_bus_space_handle, \ bus_space_write_4( ((struct em_osdep *)(hw)->back)->mem_bus_space_tag, \
((a)->mac_type >= em_82543) ? E1000_##reg : E1000_82542_##reg, \ ((struct em_osdep *)(hw)->back)->mem_bus_space_handle, \
value)) offset, \
value)
#define E1000_READ_REG_ARRAY(a, reg, offset) (\ /* Convert a register name to its offset in the adapter's memory space */
((a)->mac_type >= em_82543) ? \ #define E1000_REG_OFFSET(hw, reg) \
bus_space_read_4( ((struct em_osdep *)(a)->back)->mem_bus_space_tag, \ ((hw)->mac_type >= em_82543 ? E1000_##reg : E1000_82542_##reg)
((struct em_osdep *)(a)->back)->mem_bus_space_handle, \
(E1000_##reg + ((offset) << 2))): \
bus_space_read_4( ((struct em_osdep *)(a)->back)->mem_bus_space_tag, \
((struct em_osdep *)(a)->back)->mem_bus_space_handle, \
(E1000_82542_##reg + ((offset) << 2))))
#define E1000_READ_REG(hw, reg) \
E1000_READ_OFFSET(hw, E1000_REG_OFFSET(hw, reg))
#define E1000_WRITE_REG_ARRAY(a, reg, offset, value) (\ #define E1000_WRITE_REG(hw, reg, value) \
((a)->mac_type >= em_82543) ? \ E1000_WRITE_OFFSET(hw, E1000_REG_OFFSET(hw, reg), value)
bus_space_write_4( ((struct em_osdep *)(a)->back)->mem_bus_space_tag, \
((struct em_osdep *)(a)->back)->mem_bus_space_handle, \
(E1000_##reg + ((offset) << 2)), value): \
bus_space_write_4( ((struct em_osdep *)(a)->back)->mem_bus_space_tag, \
((struct em_osdep *)(a)->back)->mem_bus_space_handle, \
(E1000_82542_##reg + ((offset) << 2)), value))
#define E1000_READ_REG_ARRAY(hw, reg, index) \
E1000_READ_OFFSET(hw, E1000_REG_OFFSET(hw, reg) + ((index) << 2))
#define E1000_WRITE_REG_ARRAY(hw, reg, index, value) \
E1000_WRITE_OFFSET(hw, E1000_REG_OFFSET(hw, reg) + ((index) << 2), value)
#endif /* _FREEBSD_OS_H_ */ #endif /* _FREEBSD_OS_H_ */