Even though we do software interrupt mitigation
via NAPI, it still helps to have some minimal
hw assisted mitigation.
This helps, particularly, on systems where register
I/O overhead is much greater than the CPU horsepower.
For example, it helps on NUMA systems. In such cases
the PIO overhead to disable interrupts for NAPI accounts
for the majority of the packet processing cost. The
CPU is fast enough such that only a single packet is
processed by each NAPI poll call.
Thanks to Michael Chan for reviewing this patch.
Signed-off-by: David S. Miller <davem@davemloft.net>
When supported, use the TAGGED interrupt processing support
the chip provides. In this mode, instead of a "on/off" binary
semaphore, an incrementing tag scheme is used to ACK interrupts.
All MSI supporting chips support TAGGED mode, so the tg3_msi()
interrupt handler uses it unconditionally. This invariant is
verified when MSI support is tested.
Since we can invoke tg3_poll() multiple times per interrupt under
high packet load, we fetch a new copy of the tag value in the
status block right before we actually do the work.
Also, because the tagged status tells the chip exactly which
work we have processed, we can make two optimizations:
1) tg3_restart_ints() need not check tg3_has_work()
2) the tg3_timer() need not poke the chip 10 times per
second to keep from losing interrupt events
Based upon valuable feedback from Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add support for the NVRAM lock-out feature for TPM in 5752. If lock-out
is enabled, certain NVRAM registers cannot be written to.
Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add bit definitions for the new GPIO3 in 5752. GPIO3 must be driven as
output when it is unused.
Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The 5752 A0 chip ID is wrong in hardware. The simplest way to workaround
it is to change it to the correct value in tp->pci_chip_rev_id. This
way, it is easier to check for the ASIC_REV_5752 in the rest of the
driver.
Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Some minor 5752 fixes mostly for correctness and add 5752 PHY ID.
Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Replace existing ASIC_REV_5752 definition with ASIC_REV_5752_A0,
and add definition for ASIC_REV_5752_A1. Then, add ASIC_REV_5752_A1
to check for setting TG3_FLG2_5750_PLUS in tg3_get_invariants.
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Define TG3_FLG2_5750_PLUS flag and set it in tg3_get_invariants for
ASIC_REV_5750 or ASIC_REV_5752.
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add ASIC_REV_5752 definition.
Track-down all references to ASIC_REV_5750 and mirror them with
references to the newly defined ASIC_REV_5752.
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
David S. Miller