Fix the following BUG_ON() problem reported by Alex Chiang.
This problem happened when removing PCIe root port using PCI logical
hotplug operation.
The immediate cause of this problem is that the pointer to invalid
data structure is passed to pcie_update_aspm_capable() by
pcie_aspm_exit_link_state(). When pcie_aspm_exit_link_state() received
a pointer to root port link, it unconfigures the root port link and
frees its data structure at first. At this point, there are not links
to configure under the root port and the data structure for root port
link is already freed. So pcie_aspm_exit_link_state() must not call
pcie_update_aspm_capable() and pcie_config_aspm_path().
This patch fixes the problem by changing pcie_aspm_exit_link_state()
not to call pcie_update_aspm_capable() and pcie_config_aspm_path() if
the specified link is root port link.
------------[ cut here ]------------
kernel BUG at drivers/pci/pcie/aspm.c:606!
invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC
last sysfs file: /sys/devices/pci0000:40/0000:40:13.0/remove
CPU 1
Modules linked in: shpchp
Pid: 9345, comm: sysfsd Not tainted 2.6.32-rc5 #98 ProLiant DL785 G6
RIP: 0010:[<ffffffff811df69b>] [<ffffffff811df69b>] pcie_update_aspm_capable+0x15/0xbe
RSP: 0018:ffff88082a2f5ca0 EFLAGS: 00010202
RAX: 0000000000000e77 RBX: ffff88182cc3e000 RCX: ffff88082a33d006
RDX: 0000000000000001 RSI: ffffffff811dff4a RDI: ffff88182cc3e000
RBP: ffff88082a2f5cc0 R08: ffff88182cc3e000 R09: 0000000000000000
R10: ffff88182fc00180 R11: ffff88182fc00198 R12: ffff88182cc3e000
R13: 0000000000000000 R14: ffff88182cc3e000 R15: ffff88082a2f5e20
FS: 00007f259a64b6f0(0000) GS:ffff880864600000(0000) knlGS:0000000000000000
CS: 0010 DS: 0018 ES: 0018 CR0: 000000008005003b
CR2: 00007feb53f73da0 CR3: 000000102cc94000 CR4: 00000000000006e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process sysfsd (pid: 9345, threadinfo ffff88082a2f4000, task ffff88082a33cf00)
Stack:
ffff88182cc3e000 ffff88182cc3e000 0000000000000000 ffff88082a33cf00
<0> ffff88082a2f5cf0 ffffffff811dff52 ffff88082a2f5cf0 ffff88082c525168
<0> ffff88402c9fd2f8 ffff88402c9fd2f8 ffff88082a2f5d20 ffffffff811d7db2
Call Trace:
[<ffffffff811dff52>] pcie_aspm_exit_link_state+0xf5/0x11e
[<ffffffff811d7db2>] pci_stop_bus_device+0x76/0x7e
[<ffffffff811d7d67>] pci_stop_bus_device+0x2b/0x7e
[<ffffffff811d7e4f>] pci_remove_bus_device+0x15/0xb9
[<ffffffff811dcb8c>] remove_callback+0x29/0x3a
[<ffffffff81135aeb>] sysfs_schedule_callback_work+0x15/0x6d
[<ffffffff81072790>] worker_thread+0x19d/0x298
[<ffffffff8107273b>] ? worker_thread+0x148/0x298
[<ffffffff81135ad6>] ? sysfs_schedule_callback_work+0x0/0x6d
[<ffffffff810765c0>] ? autoremove_wake_function+0x0/0x38
[<ffffffff810725f3>] ? worker_thread+0x0/0x298
[<ffffffff8107629e>] kthread+0x7d/0x85
[<ffffffff8102eafa>] child_rip+0xa/0x20
[<ffffffff8102e4bc>] ? restore_args+0x0/0x30
[<ffffffff81076221>] ? kthread+0x0/0x85
[<ffffffff8102eaf0>] ? child_rip+0x0/0x20
Code: 89 e5 8a 50 48 31 c0 c0 ea 03 83 e2 07 e8 b2 de fe ff c9 48 98 c3 55 48 89 e5 41 56 49 89 fe 41 55 41 54 53 48 83 7f 10 00 74 04 <0f> 0b eb fe 48 8b 05 da 7d 63 00 4c 8d 60 e8 4c 89 e1 eb 24 4c
RIP [<ffffffff811df69b>] pcie_update_aspm_capable+0x15/0xbe
RSP <ffff88082a2f5ca0>
---[ end trace 6ae0f65bdeab8555 ]---
Reported-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Tested-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6:
PCI: Prevent AER driver from being loaded on non-root port PCIE devices
PCI: get larger bridge ranges when space is available
PCI: pci.c: fix kernel-doc notation
PCI quirk: TI XIO200a erroneously reports support for fast b2b transfers
PCI PM: Read device power state from register after updating it
PCI: remove pci_assign_resource_fixed()
PCI: PCIe portdrv: remove "-driver" from driver name
After m68k's task_thread_info() doesn't refer to current,
it's possible to remove sched.h from interrupt.h and not break m68k!
Many thanks to Heiko Carstens for allowing this.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
A bug was seen on boards using a PLX 8518 switch device which advertises
AER on each of it's transparent bridges. The AER driver was loaded for
each bridge and this driver tried to access the AER source ID register
whenever an interrupt occured on the shared PCI INTX lines. The source
ID register does not exist on non root port PCIE device's which
advertise AER and trying to access this register causes a unsupported
request error on the bridge. Thus, when the next interrupt occurs,
another error is found and the non existent source ID register is
accessed again, and so it goes on.
The result is a spammed dmesg with unsupported request PCI express
errors on the bridge device that the AER driver is loaded against.
Reported-by: Malcolm Crossley <malcolm.crossley2@gefanuc.com>
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Tested-by: Malcolm Crossley <malcolm.crossley2@gefanuc.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
No need to include "-driver" in the driver name.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
CC: Tom Long Nguyen <tom.l.nguyen@intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
When booting with pci=nomsi aer causes lost interrupts and
lockdep inversions.
So check if MSIs are not disabled before initializing the aer
driver.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
The definition of the ASPM support field in the Link Capabilities
Register had been changed by the "ASPM optionality ECN" as follows:
<Before>
00b Reserved
01b L0s Supported
10b Reserved
11b L0s and L1 Supported
<After>
00b No ASPM Support
01b L0s Supported
10b L1 Supported
11b L0s and L1 Supported
Current linux ASPM driver doesn't enable ASPM if the support field is
00b or 10b. So there is no impact about 00b. But current linux ASPM
driver doesn't enable L1 if the support field is 10b. With this patch,
10b (L1 support) is handled properly.
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
After commit c82f63e411
(PCI: check saved state before restore) pcie_portdrv_slot_reset()
may not work correctly if dev->error_state is equal to
pci_channel_io_frozen, because dev->state_saved need not be set at
that time. Fix this issue by setting dev->state_saved before
pci_restore_state() is called in pcie_portdrv_slot_reset().
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
There is a very old quirk for the intel E7502 E7320 and E7525 memory
controller hubs that disables usage of msi interrupts on pcie hotplug
bridges of those devices, and disables changing the affinity of irqs.
Today all we have to do to disable msi on a specific device is to set
dev->no_msi, which is much more straightforward than the previous
logic.
The re-running of this fixup after pci hotplug happens below these
devices is totally bogus. All of the state we change is pure software
state and we don't change the hardware at all. Which means hotplug on
the lower devices doesn't have a chance to change this state. So we
can safely remove the special case from the pciehp driver and the pcie
portdriver.
I suspect the special case was someone's expermental debug code that
slipped in. Certainly it isn't mentioned in commit
6fb8880a61510295aece04a542767161f624dffe aka BKrev:
41966101LJ_ogfOU0m2aE6teZfQnuQ where the code first appears.
Reviewed-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Multiple bits might be set in the Uncorrectable Error Status
register. But aer_print_error_source() only report a error of
the lowest bit set in the error status register.
So print strings for all bits unmasked and set.
And check First Error Pointer to mark the error occured first.
This FEP is not valid when the corresponing bit of the Uncorrectable
Error Status register is not set, or unimplemented or undefined.
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
ERR_{,UN}CORRECTABLE_ERROR_MASK are set of error bits which linux know,
set of PCI_ERR_COR_* and PCI_ERR_UNC_* defined in linux/pci_regs.h.
This masks make aerdrv not to report errors of unknown bit, while aerdrv
have ability to report such undefined errors as "Unknown Error Bit %2d".
OTOH aerdrv_errprint does not have any check of setting in mask register.
So it could report masked wrong error by finding bit in status without
knowing that the bit is masked in the mask register.
This patch changes aerdrv to use mask state in mask register propely
instead of defined/hardcoded ERR_{,UN}CORRECTABLE_ERROR_MASK.
This change prevents aerdrv from reporting masked error, and also enable
reporting unknown errors.
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Reviewed-by: Andrew Patterson <andrew.patterson@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
The static buffer errmsg_buff[] is used only for building error
message in fixed format, and is protected by a spinlock.
This patch removes this buffer and the spinlock.
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Reviewed-by: Andrew Patterson <andrew.patterson@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
The flag AER_MULTI_ERROR_VALID_FLAG in info->flag does mean that the
root port receives multiple error messages. Error messages can be
posted from different devices, so it does not mean that each reported
device has multiple errors.
If there are multiple error devices and the root port has valid error
source ID, it would be nice to report which device is the error source
reported first.
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
In case of multiple errors, struct aer_err_info would be reused among
all reported devices. So the info->status should be initialized before
recycled. Otherwise error of one device might be reported as the error
of another device. Also info->flags has similar problem on reporting
TLP header.
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Definitions of MASK macros in aerdrv_errprint.c are tricky and unsafe.
For example, AER_AGENT_TRANSMITTER_MASK(_sev, _stat) does work like:
static inline func(int _sev, int _stat)
{
if (_sev == AER_CORRECTABLE)
return (_stat & (PCI_ERR_COR_REP_ROLL|PCI_ERR_COR_REP_TIMER));
else
return (_stat & PCI_ERR_COR_REP_ROLL);
}
In case of else path here, for uncorrectable errors, testing bits in
_stat by PCI_ERR_COR_* does not make sense because _stat should have only
PCI_ERR_UNC_* bits originated in uncorrectable error status register.
But at this time this is safe because uncorrectable error using bit
position same to PCI_ERR_COR_REP_ROLL(= bit position 8) is not defined.
Likewise, AER_AGENT_COMPLETER_MASK is always PCI_ERR_UNC_COMP_ABORT but
it works because bit 15 of correctable error status is not defined.
It means that these MASK macros will turn to be wrong once if new error
is defined. (In fact, bit 15 of correctable is now defined in PCIe 2.1)
This patch changes these MASK macros to be more strict, not to return
PCI_ERR_COR_* bits for uncorrectable error status and vise versa.
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Reviewed-by: Andrew Patterson <andrew.patterson@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
The L0s state can be managed separately for each direction (upstream
direction and downstream direction) of the link. But in the current
implementation, those are mixed up. With this patch, L0s for each
direction are managed separately.
To maintain three states (upstream direction L0s, downstream L0s and
L1), 'aspm_support', 'aspm_enabled', 'aspm_capable', 'aspm_disable'
and 'aspm_default' fields in struct pcie_link_state are changed to
3-bit from 2-bit. The 'latency' field is separated to two 'latency_up'
and 'latency_dw' fields to maintain exit latencies for each direction
of the link. For L0, 'latency_up.l0' and 'latency_dw.l0' are used to
configure upstream direction L0s and downstream direction L0s
respectively. For L1, larger value of 'latency_up.l1' and
'latency_dw.l1' is considered as L1 exit latency.
Acked-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
In the current implementation, ASPM L0s/L1 is disabled for all links
in the hierarchy if one of the link doesn't meet latency requirement.
But we can partially enable ASPM L0s/L1 on sub-tree in the hierarchy.
This patch allows partial L0s/L1 enablement in the hierarchy. And it
also reduce the calculation cost of ASPM configuration very much.
In the previous implementation, all links were enabled with the same
state. With this patch, enabled state for each link is determined
simply as follows (the 'requested' is from policy_to_aspm_state()).
enabled = requested & (link->aspm_capable & link->aspm_disable)
Acked-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Introduce 'aspm_capable' field to maintain the capable ASPM setting of
the link. By the 'aspm_capable', we don't need to recheck latency
every time ASPM policy is changed.
Each bit in 'aspm_capable' is associated to ASPM state (L0S/L1). The
bit is set if the associated ASPM state is supported by the link and
it satisfies the latency requirement (i.e. exit latency < endpoint
acceptable latency). The 'aspm_capable' is updated when
- an endpoint device is added (boot time or hot-plug time)
- an endpoint device is removed (hot-unplug time)
- PCI power state is changed.
Acked-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Introduce 'aspm_disable' flag to manage disabled ASPM state more
robust way.
Acked-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Fix possible NULL dereference in pcie_aspm_exit_link_state(). This
patch also cleanup some code.
Acked-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Remove the following check in __pcie_aspm_config_link() because it
nerver be true.
Acked-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
We must not clear bits in 'aspm_enabled' using 'aspm_support', or
'aspm_enabled' and 'aspm_default' might be different from the actual
state. In addtion, 'aspm_default' should be intialized even if
'aspm_support' is 0.
Acked-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
By having a pointer to the root port link, we can remove loops in
get_root_port_link() to search the root port link.
Acked-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
We don't need the 'has_switch' field in the struct pcie_link_state.
Acked-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Cleanup for calc_L0S_latency() and calc_L1_latency().
- Separate exit latency and acceptable latency calculation.
- Some minor cleanups.
Acked-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
In the current ASPM implementation, callers of pcie_set_clock_pm() check
Clock PM capability of the link or current Clock PM state of the link.
This check should be done in pcie_set_clock_pm() itself.
This patch moves those checks into pcie_set_clock_pm(). It also
introduces pcie_set_clkpm_nocheck() that is equivalent to old
pcie_set_clock_pm(), for the caller who wants to change Clocl PM state
regardless of the Clock PM capability or current Clock PM state. In
addition, this patch changes the function name from
pcie_set_clock_pm() to pcie_set_clkpm() for consistency.
Acked-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Clean up ASPM initialization by refactoring some functionality, renaming
functions, and moving things around.
Acked-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
In the current ASPM implementation, there are many functions that
take a pointer to struct pci_dev corresponding to the upstream component
of the link as a parameter. But, since those functions handle PCI
express link state, a pointer to struct pcie_link_state is more
suitable than a pointer to struct pci_dev. Changing a parameter to a
pointer to struct pcie_link_state makes ASPM code much simpler and
easier to read. This patch also contains some minor cleanups. This patch
doesn't have any functional change.
Acked-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Cleanup for some fields in pcie_link_state.
- Add comments.
- make "downstream_has_switch" field 1-bit.
Acked-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
The "clk_pm_capable", "clk_pm_enable" and "bios_clk_state" fields in
the struct pcie_link_state only take 1-bit value. So those fields
don't need to be defined as unsigned int. This patch makes those
fields 1-bit, and cleans up some related code.
Acked-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Clean up latency related data structures for ASPM.
- Introduce struct acpi_latency for exit latency and acceptable
latency management. With this change, struct endpoint_state is no
longer needed.
- We don't need to hold both upstream latency and downstream latency
in the current implementation.
Acked-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
The "support_state", "enabled_state" and "bios_aspm_state" fields in
the struct pcie_link_state take 2-bit value. So those fields don't
need to be defined as unsigned int. This patch makes those fields
2-bit, and cleans up some related code.
Acked-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Fix a typo in struct pcie_link_state.
The "sibiling" field in the struct pcie_link_state should be
"sibling".
Acked-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Debugging PCIE AER code can be very difficult because it is hard
to trigger various real hardware errors. This patch provide a
software based error injection tool, which can fake various PCIE
errors with a user space helper tool named "aer-inject". Which
can be gotten from:
http://www.kernel.org/pub/linux/kernel/people/yhuang/
The patch fakes AER error by faking some PCIE AER related
registers and an AER interrupt for specified the PCIE device.
Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
When a root port receives the same errors more than once before the
kernel process them, the Multiple Error Messages Received flags are set
by hardware. Because the root port could only save one kind of
correctable error source id and another uncorrectable error source id at
the same time, the second message sender id is lost if the 2 messages
are sent from 2 different devices. This patch makes the kernel search
all devices under the root port when multiple messages are received.
Reviewed-by: Andrew Patterson <andrew.patterson@hp.com>
Signed-off-by: Zhang Yanmin <yanmin_zhang@linux.intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
When the bus id part of error source id is equal to 0 or nosourceid=1,
make the kernel probe the AER status registers of all devices under the
root port to find the initial error reporter.
Reviewed-by: Andrew Patterson <andrew.patterson@hp.com>
Signed-off-by: Zhang Yanmin <yanmin_zhang@linux.intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Based on PCI Express AER specs, a root port might receive multiple
TLP errors while it could only save a correctable error source id
and an uncorrectable error source id at the same time. In addition,
some root port hardware might be unable to provide a correct source
id, i.e., the source id, or the bus id part of the source id provided
by root port might be equal to 0.
The patchset implements the support in kernel by searching the device
tree under the root port.
Patch 1 changes parameter cb of function pci_walk_bus to return a value.
When cb return non-zero, pci_walk_bus stops more searching on the
device tree.
Reviewed-by: Andrew Patterson <andrew.patterson@hp.com>
Signed-off-by: Zhang Yanmin <yanmin_zhang@linux.intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
This is used by PCIE AER error injection to fake an PCI AER interrupt.
Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Adds support for PCI Express transaction layer end-to-end CRC checking
(ECRC). This patch will enable/disable ECRC checking by setting/clearing
the ECRC Check Enable and/or ECRC Generation Enable bits for devices that
support ECRC.
The ECRC setting is controlled by the "pci=ecrc=<policy>" command-line
option. If this option is not set or is set to 'bios", the enable and
generation bits are left in whatever state that firmware/BIOS set them to.
The "off" setting turns them off, and the "on" option turns them on (if the
device supports it).
Turning ECRC on or off can be a data integrity versus performance
tradeoff. In theory, turning it on will catch more data errors, turning
it off means possibly better performance since CRC does not need to be
calculated by the PCIe hardware and packet sizes are reduced.
Signed-off-by: Andrew Patterson <andrew.patterson@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
