Commit Graph

91 Commits

Author SHA1 Message Date
Yinghai Lu
3145e941fc x86, MSI: pass irq_cfg and irq_desc
Impact: simplify code

Pass irq_desc and cfg around, instead of raw IRQ numbers - this way
we dont have to look it up again and again.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-08 14:31:59 +01:00
Taku Izumi
d389fec6a2 ACPI/PCI: Set support bit for MSI in support field of _OSC
Currently linux doesn't have any code to set the "MSI supported" bit in
Support Fireld of _OSC. This patch adds the code for that.

Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Taku Izumi <izumi.taku@jp.fujitsu.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2008-10-22 16:42:35 -07:00
Jike Song
5993760f7f PCI: utilize calculated results when detecting MSI features
In msi_capability_init, we can make use of the calculated results
instead of calling is_mask_bit_support and is_64bit_address twice.

Signed-off-by: Jike Song <albcamus@gmail.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2008-10-20 10:53:50 -07:00
Jesse Barnes
abad2ec98f PCI: fully restore MSI state at resume time
With the recent change to avoid masking MSIs using the MSI enable bit, devices
without an MSI mask bit will have their MSI capability always enabled when MSI
is in use, so we need to restore it regardless of the mask bit state.

Fixes kernel bz 11178.

Acked-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Alan Jenkins <alan-jenkins@tuffmail.co.uk>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2008-08-07 08:52:37 -07:00
Matthew Wilcox
ce6fce4295 PCI MSI: Don't disable MSIs if the mask bit isn't supported
David Vrabel has a device which generates an interrupt storm on the INTx
pin if we disable MSI interrupts altogether.  Masking interrupts is only
a performance optimisation, so we can ignore the request to mask the
interrupt.

Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2008-07-28 14:43:22 -07:00
Bjorn Helgaas
80ccba1186 PCI: use dev_printk when possible
Convert printks to use dev_printk().

I converted pr_debug() to dev_dbg().  Both use KERN_DEBUG and are enabled
only when DEBUG is defined.

I converted printk(KERN_DEBUG) to dev_printk(KERN_DEBUG), not to dev_dbg(),
because dev_dbg() is only enabled when DEBUG is defined.

I converted DBG(KERN_INFO) (only in setup-bus.c) to dev_info().  The DBG()
name makes it sound like debug, but it's been enabled forever, so dev_info()
preserves the previous behavior.

I tried to make the resource assignment formats more consistent, e.g.,
  "BAR %d: got res [%#llx-%#llx] bus [%#llx-%#llx] flags %#lx\n"
instead of sometimes using "start-end" and sometimes using "size@start".
I'm not attached to one or the other; I'd just like them consistent.

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2008-06-25 16:05:13 -07:00
Hidetoshi Seto
5ca5c02f0e PCI/MSI: skip calling pci_find_capability from msi_set_mask_bits
The position of MSI capability is already cached in the msi_desc when
we enter the msi_set_mask_bits().  Use it instead.

Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2008-06-10 10:59:49 -07:00
Yinghai Lu
d52877c7b1 pci/irq: let pci_device_shutdown to call pci_msi_shutdown v2
[PATCH 2/2] pci/irq: let pci_device_shutdown to call pci_msi_shutdown v2

this change

| commit 23a274c8a5
| Author: Prakash, Sathya <sathya.prakash@lsi.com>
| Date:   Fri Mar 7 15:53:21 2008 +0530
|
|     [SCSI] mpt fusion: Enable MSI by default for SAS controllers
|
|     This patch modifies the driver to enable MSI by default for all SAS chips.
|
|     Signed-off-by: Sathya Prakash <sathya.prakash@lsi.com>
|     Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
|
Causes the kexec of a RHEL 5.1 kernel to fail.

root casue: the rhel 5.1 kernel still uses INTx emulation.  and
mptscsih_shutdown doesn't call pci_disable_msi to reenable INTx on kexec path

So call pci_msi_shutdown in the shutdown path to do the same thing to msix

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Jesse Barnes <jbarnes@hobbes.lan>
2008-04-29 09:12:51 -07:00
Yinghai Lu
8e149e09f9 pci/irq: restore mask_bits in msi shutdown -v3
[PATCH 1/2] pci/irq: restore mask_bits in msi shutdown -v3

Yinghai found that kexec'ing a RHEL 5.1 kernel with 2.6.25-rc3+ kernels
prevents his NIC from working.  He bisected to

| commit 89d694b9db
| Author: Thomas Gleixner <tglx@linutronix.de>
| Date:   Mon Feb 18 18:25:17 2008 +0100
|
|   genirq: do not leave interupts enabled on free_irq
|
|   The default_disable() function was changed in commit:
|
|    76d2160147
|    genirq: do not mask interrupts by default
|

For MSI, default_shutdown will call mask_bit for msi device.  All mask bits
will left disabled after free_irq.  Then in the kexec case, the next kernel
can only use msi_enable bit, so all device's MSI can not be used.

So lets to restore the mask bit to its pci reset defined value (enabled) when
we disable the kernels use of msi to be a little friendlier to kexec'd kernels.

Extend msi_set_mask_bit to msi_set_mask_bits to take mask, so we can fully
restore that to 0x00 instead of 0xfe.

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Jesse Barnes <jbarnes@hobbes.lan>
2008-04-29 09:11:12 -07:00
Adrian Bunk
6a9e7f2031 PCI: drivers/pci/msi.c: move arch hooks to the top
This patch fixes the following problem present with older gcc versions:

<--  snip  -->

...
  CC      drivers/pci/msi.o
/home/bunk/linux/kernel-2.6/git/linux-2.6/drivers/pci/msi.c:692: warning: weak declaration of `arch_msi_check_device' after first use results in unspecified behavior
/home/bunk/linux/kernel-2.6/git/linux-2.6/drivers/pci/msi.c:704: warning: weak declaration of `arch_setup_msi_irqs' after first use results in unspecified behavior
/home/bunk/linux/kernel-2.6/git/linux-2.6/drivers/pci/msi.c:724: warning: weak declaration of `arch_teardown_msi_irqs' after first use results in unspecified behavior
...

<--  snip  -->

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-01 15:04:25 -08:00
Linas Vepstas
94688cf245 PCI: export pci_restore_msi_state()
PCI error recovery usually involves the PCI adapter being reset.
If the device is using MSI, the reset will cause the MSI state
to be lost; the device driver needs to restore the MSI state.

The pci_restore_msi_state() routine is currently protected
by CONFIG_PM; remove this, and also export the symbol, so
that it can be used in a modle.

Signed-off-by: Linas Vepstas <linas@austin.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-01 15:04:22 -08:00
David Miller
ba698ad4b7 PCI: Add quirk for devices which disable MSI when INTX_DISABLE is set.
A reasonably common problem with some devices is that they will
disable MSI generation when the INTX_DISABLE bit is set in the
PCI_COMMAND register.

Quirk this explicitly, guarding the pci_intx() calls in msi.c with
this quirk indication.

The first entries for this quirk are for 5714 and 5780 Tigon3 chips,
and thus we can remove the workaround code from the tg3.c driver.

Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Michael Chan <mchan@broadcom.com>
Acked-by: Jeff Garzik <jgarzik@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-11-05 13:35:16 -08:00
Roland Dreier
cbf5d9e6b9 MSI: Use correct data offset for 32-bit MSI in read_msi_msg()
While reading the MSI code trying to find a reason why MSI wouldn't
work for devices that have a 32-bit MSI address capability, I noticed
that read_msi_msg() seems to read the message data from the wrong
offset in this case.

Signed-off-by: Roland Dreier <roland@digitalvampire.org>
Acked-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-10-12 15:03:17 -07:00
Eric W. Biederman
78b7611c4a msi: mask the msix vector before we unmap it
With these two lines in the reverse order the drives/block/ccis.c was
oopsing in msi_free_irqs.  Silly us calling writel on an area after
we unmap it.

BUG: unable to handle kernel paging request at virtual address f8b2200c
 printing eip:
c01e9cc7
*pdpt = 0000000000003001
*pde = 0000000037e48067
*pte = 0000000000000000
Oops: 0002 [#1]
SMP
Modules linked in: cciss ipv6 parport_pc lp parport autofs4 i2c_dev i2c_core
sunrpc loop dm_multipath button battery asus_acpi ac tg3 floppy sg dm_snapshot
dm_zero dm_mirror ext3 jbd dm_mod ata_piix libata mptsas scsi_transport_sas
mptspi scsi_transport_spi mptscsih mptbase sd_mod scsi_mod
CPU:    1
EIP:    0060:[<c01e9cc7>]    Not tainted VLI
EFLAGS: 00010286   (2.6.22-rc2-gd2579053 #1)
EIP is at msi_free_irqs+0x81/0xbe
eax: f8b22000   ebx: f71f3180   ecx: f7fff280   edx: c1886eb8
esi: f7c4e800   edi: f7c4ec48   ebp: 00000002   esp: f5a0dec8
ds: 007b   es: 007b   fs: 00d8  gs: 0033  ss: 0068
Process rmmod (pid: 5286, ti=f5a0d000 task=c47d2550 task.ti=f5a0d000)
Stack: 00000002 f8b72294 00000400 f8b69ca7 f8b6bc6c 00000002 00000000 00000000
       00000000 00000000 00000000 f5a997f4 f8b69d61 f7c5a4b0 f7c4e848 f7c4e848
       f7c4e800 f7c4e800 f8b72294 f7c4e848 f8b72294 c01e3cdf f7c4e848 c024c469
Call Trace:
 [<f8b69ca7>] cciss_shutdown+0xae/0xc3 [cciss]
 [<f8b69d61>] cciss_remove_one+0xa5/0x178 [cciss]
 [<c01e3cdf>] pci_device_remove+0x16/0x35
 [<c024c469>] __device_release_driver+0x71/0x8e
 [<c024c56e>] driver_detach+0xa0/0xde
 [<c024bc5c>] bus_remove_driver+0x27/0x41
 [<c01e3ef3>] pci_unregister_driver+0xb/0x13
 [<f8b6a343>] cciss_cleanup+0xf/0x51 [cciss]
 [<c0139ced>] sys_delete_module+0x110/0x135
 [<c0104c7a>] sysenter_past_esp+0x5f/0x85

Here's a patch that just reverses the 2 lines of code as Eric suggests. Please
consider this for inclusion.

Signed-off-by: Mike Miller <mike.miller@hp.com>
Signed-off-by: Chase Maupin <chase.maupin@hp.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-06-01 08:18:27 -07:00
Eric W. Biederman
0dd11f9be4 msi: fix the ordering of msix irqs
"Mike Miller (OS Dev)" <mikem@beardog.cca.cpqcorp.net> writes:

Found what seems the problem with our vectors being listed backward.  In
drivers/pci/msi.c we should be using list_add_tail rather than list_add to
preserve the ordering across various kernels.  Please consider this for
inclusion.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Screwed-up-by: Michael Ellerman <michael@ellerman.id.au>
Cc: "Mike Miller (OS Dev)" <mikem@beardog.cca.cpqcorp.net>
Cc: Andi Kleen <ak@suse.de>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-06-01 08:18:27 -07:00
Dan Williams
4fdadebc31 msi: fix ARM compile
In file included from drivers/pci/msi.c:22:
include/asm/smp.h:17:26: asm/arch/smp.h: No such file or directory
include/asm/smp.h:20:3: #error "<asm-arm/smp.h> included in non-SMP build"
include/asm/smp.h:23:1: warning: "raw_smp_processor_id" redefined
In file included from include/linux/sched.h:65,
                 from include/linux/mm.h:4,
                 from drivers/pci/msi.c:10:
include/linux/smp.h:85:1: warning: this is the location of the previous
definition

Tested on powerpc, i386, and x86_64.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-05-31 16:56:36 -07:00
David Miller
b3b7cc7b41 Fix assertion failure with MSI on sparc64
Today's find is a triggered assertion in msi_free_irqs() when the system
doesn't support MSI, in which case arch_setup_msi_irqs() always returns
an error.

The problem is that when this happens we branch into msi_free_irqs(), to
which you added the following assertion loop:

	list_for_each_entry(entry, &dev->msi_list, list)
		BUG_ON(irq_has_action(entry->irq));

Well, if arch_setup_msi_irqs() fails, entry->irq will be zero and
although that's never assigned to any normal devices we use that IRQ
number for the timer interrupt on sparc64 so this assertion triggers.

Better to test for zero before doing the irq_has_action() assertion
thing.

Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-11 16:01:18 -07:00
Randy Dunlap
e63340ae6b header cleaning: don't include smp_lock.h when not used
Remove includes of <linux/smp_lock.h> where it is not used/needed.
Suggested by Al Viro.

Builds cleanly on x86_64, i386, alpha, ia64, powerpc, sparc,
sparc64, and arm (all 59 defconfigs).

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08 11:15:07 -07:00
Michael Ellerman
032de8e2fe MSI: Give archs the option to free all MSI/Xs at once.
This patch introduces an optional function, arch_teardown_msi_irqs(),
which gives an arch the opportunity to do per-device teardown for
MSI/X. If that's not required, the default version simply calls
arch_teardown_msi_irq() for each msi irq required.

arch_teardown_msi_irqs() is simply passed a pdev, attached to the pdev
is a list of msi_descs, it is up to the arch to free the irq associated
with each of these as appropriate.

For archs that _don't_ implement arch_teardown_msi_irqs(), all msi_descs
with irq == 0 are considered unallocated, and the arch teardown routine
is not called on them.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-05-02 19:02:38 -07:00
Michael Ellerman
9c8313343c MSI: Give archs the option to allocate all MSI/Xs at once.
This patch introduces an optional function, arch_setup_msi_irqs(),
(note the plural) which gives an arch the opportunity to do per-device
setup for MSI/X and then allocate all the requested MSI/Xs at once.

If that's not required by the arch, the default version simply calls
arch_setup_msi_irq() for each MSI irq required.

arch_setup_msi_irqs() is passed a pdev, attached to the pdev is a list
of msi_descs with irq == 0, it is up to the arch to connect these up to
an irq (via set_irq_msi()) or return an error. For convenience the number
of vectors and the type are passed also.

All msi_descs with irq != 0 are considered allocated, and the arch
teardown routine will be called on them when necessary.

The existing semantics of pci_enable_msix() are that if the requested
number of irqs can not be allocated, the maximum number that _could_ be
allocated is returned. To support that, we define that in case of an
error from arch_setup_msi_irqs(), the number of msi_descs with irq != 0
are considered allocated, and are counted toward the "max that could be
allocated".


Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-05-02 19:02:38 -07:00
Michael Ellerman
7fe3730de7 MSI: arch must connect the irq and the msi_desc
set_irq_msi() currently connects an irq_desc to an msi_desc. The archs call
it at some point in their setup routine, and then the generic code sets up the
reverse mapping from the msi_desc back to the irq.

set_irq_msi() should do both connections, making it the one and only call
required to connect an irq with it's MSI desc and vice versa.

The arch code MUST call set_irq_msi(), and it must do so only once it's sure
it's not going to fail the irq allocation.

Given that there's no need for the arch to return the irq anymore, the return
value from the arch setup routine just becomes 0 for success and anything else
for failure.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-05-02 19:02:38 -07:00
Michael Ellerman
314e77b3ee MSI: Remove dev->first_msi_irq
Now that we keep a list of msi descriptors, we don't need first_msi_irq
in the pci dev.

If we somehow have zero MSIs configured list_entry() will give us weird
oopes or nice memory corruption bugs. So be paranoid. Add BUG_ONs and also
a check in pci_msi_check_device() to make sure nvec > 0.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-05-02 19:02:37 -07:00
Michael Ellerman
4aa9bc955d MSI: Use a list instead of the custom link structure
The msi descriptors are linked together with what looks a lot like
a linked list, but isn't a struct list_head list. Make it one.

The only complication is that previously we walked a list of irqs, and
got the descriptor for each with get_irq_msi(). Now we have a list of
descriptors and need to get the irq out of it, so it needs to be in the
actual struct msi_desc. We use 0 to indicate no irq is setup.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-05-02 19:02:37 -07:00
Michael Ellerman
c9953a73e9 MSI: Add an arch_msi_check_device()
Add an arch_check_device(), which gives archs a chance to check the input
to pci_enable_msi/x. The arch might be interested in the value of nvec so
pass it in. Propagate the error value returned from the arch routine out
to the caller.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-05-02 19:02:37 -07:00
Michael Ellerman
17bbc12acd MSI: Rename pci_msi_supported() to pci_msi_check_device()
As pointed out by Eric, the name pci_msi_supported() suggests it should
return a boolean value, however it doesn't. So update the name to be
a bit less confusing and update the doco too.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-05-02 19:02:36 -07:00
Michael Ellerman
128bc5fced MSI: Consolidate precondition checks
Consolidate precondition checks into a single if statement.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Acked-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-05-02 19:02:36 -07:00
Michael Ellerman
b1e2303dba MSI: Expand pci_msi_supported()
pci_enable_msi() and pci_enable_msix() both search for the MSI/MSI-X
capability, we can fold this into pci_msi_supported() by passing the
type in.

Update the code to match the comment for pci_msi_supported(). That is
it returns 0 on success, and anything else indicates an error.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-05-02 19:02:36 -07:00
Michael Ellerman
3e916c0503 MSI: Remove msi_cache
We don't need a special cache just for msi descriptors. They're not
particularly large, under 100 bytes for sure, and don't seem to require any
special alignment etc. On most systems there will be relatively few MSIs,
and hence we waste most of a page on the cache. Better to just kzalloc the
space for the few we do need.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Acked-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-05-02 19:02:36 -07:00
Michael Ellerman
4cc086fa5b MSI: Move EXPORT_SYMBOL()s near their definition
Move EXPORT_SYMBOL()s near their definition.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Acked-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-05-02 19:02:36 -07:00
Michael Ellerman
7ede9c1fa5 MSI: Consolidate BUG_ON()s.
When freeing MSIs and MSI-Xs, we BUG_ON() if the irq has not been
freed, ie. if it still has an action. We can consolidate all of these
BUG_ON()s into msi_free_irqs() as all the code paths lead there almost
immediately anyway.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Acked-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-05-02 19:02:36 -07:00
Michael Ellerman
fc4afc7b2b MSI: Consolidate MSI-X irq freeing code
For the MSI-X case we do exactly the same logic in pci_disable_msix() and
msi_remove_pci_irq_vectors(), so consolidate them.

msi_remove_pci_irq_vectors() wasn't setting dev->first_msi_irq to 0, but
I think it should have been, so the consolidated version does.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Acked-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-05-02 19:02:36 -07:00
Michael Ellerman
00ba16ab26 MSI: Simplify BUG() handling in msi_remove_pci_irq_vectors() part 2
Although it might be nice to do a printk before BUG'ing, it's really not
necessary, and it complicates the code.

The behaviour has changed slightly, in that before we set a flag if the irq
had an action, and continued freeing the other irqs. But as I see it that's
all irrelevant because we end up BUG'ing anyway.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Acked-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-05-02 19:02:36 -07:00
Michael Ellerman
c31af39870 MSI: Simplify BUG() handling in msi_remove_pci_irq_vectors() part 1
Although it might be nice to do a printk before BUG'ing, it's really not
necessary, and it complicates the code.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Acked-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-05-02 19:02:36 -07:00
Michael Ellerman
54bc6c0b0e MSI: Simplify BUG() handling in pci_disable_msix()
Although it might be nice to do a printk before BUG'ing, it's really not
necessary, and it complicates the code.

The behaviour has changed slightly, in that before we set a flag if the irq
had an action, and continued freeing the other irqs. But as I see it that's
all irrelevant because we end up BUG'ing anyway.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Acked-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-05-02 19:02:36 -07:00
Michael Ellerman
e387b9eefe MSI: Simplify BUG() handling in pci_disable_msi()
Although it might be nice to do a printk before BUG'ing, it's really not
necessary, and it complicates the code.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Acked-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-05-02 19:02:35 -07:00
Mitch Williams
988cbb15e0 PCI: Flush MSI-X table writes
This patch fixes a kernel bug which is triggered when using the
irqbalance daemon with MSI-X hardware.

Because both MSI-X interrupt messages and MSI-X table writes are posted,
it's possible for them to cross while in-flight.  This results in
interrupts being received long after the kernel thinks they're disabled,
and in interrupts being sent to stale vectors after rebalancing.

This patch performs a read flush after writes to the MSI-X table for
mask and unmask operations.  Since the SMP affinity is set while
the interrupt is masked, and since it's unmasked immediately after,
no additional flushes are required in the various affinity setting
routines.

This patch has been validated with (unreleased) network hardware which
uses MSI-X.

Revised with input from Eric Biederman.

Signed-off-by: Mitch Williams <mitch.a.williams@intel.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-05-02 19:02:34 -07:00
Eric W. Biederman
348e3fd194 [PATCH] msi: synchronously mask and unmask msi-x irqs.
This is a simplified and actually more comprehensive form of a bug
fix from Mitch Williams <mitch.a.williams@intel.com>.

When we mask or unmask a msi-x irqs the writes may be posted because
we are writing to memory mapped region.  This means the mask and
unmask don't happen immediately but at some unspecified time in the
future.  Which is out of sync with how the mask/unmask logic work
for ioapic irqs.

The practical result is that we get very subtle and hard to track down
irq migration bugs.

This patch performs a read flush after writes to the MSI-X table for mask
and unmask operations.  Since the SMP affinity is set while the interrupt
is masked, and since it's unmasked immediately after, no additional flushes
are required in the various affinity setting routines.

The testing by Mitch Williams on his especially problematic system should
still be valid as I have only simplified the code, not changed the
functionality.

We currently have 7 drivers: cciss, mthca, cxgb3, forceth, s2io,
pcie/portdrv_core, and qla2xxx in 2.6.21 that are affected by this
problem when the hardware they driver is plugged into the right slot.

Given the difficulty of reproducing this bug and tracing it down to
anything that even remotely resembles a cause, even if people are
being affected we aren't likely to see many meaningful bug reports, and
the people who see this bug aren't likely to be able to reproduce this
bug in a timely fashion.  So it is best to get this problem fixed
as soon as we can so people don't have problems.

Then if people do have a kernel message stating "No irq for vector" we
will know it is yet another novel cause that needs a complete new
investigation.

Cc: Greg KH <greg@kroah.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Mitch Williams <mitch.a.williams@intel.com>
Acked-by: "Siddha, Suresh B" <suresh.b.siddha@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-04-03 14:02:49 -07:00
Eric W. Biederman
392ee1e6dd [PATCH] msi: Safer state caching.
There are two ways pci_save_state and pci_restore_state are used.  As
helper functions during suspend/resume, and as helper functions around
a hardware reset event.  When used as helper functions around a hardware
reset event there is no reason to believe the calls will be paired, nor
is there a good reason to believe that if we restore the msi state from
before the reset that it will match the current msi state.  Since arch
code may change the msi message without going through the driver, drivers
currently do not have enough information to even know when to call
pci_save_state to ensure they will have msi state in sync with the other
kernel irq reception data structures.

It turns out the solution is straight forward, cache the state in the
existing msi data structures (not the magic pci saved things) and
have the msi code update the cached state each time we write to the hardware.
This means we never need to read the hardware to figure out what the hardware
state should be.

By modifying the caching in this manner we get to remove our save_state
routines and only need to provide restore_state routines.

The only fields that were at all tricky to regenerate were the msi and msi-x
control registers and the way we regenerate them currently is a bit dependent
upon assumptions on how we use the allow msi registers to be configured and used
making the code a little bit brittle.  If we ever change what cases we allow
or how we configure the msi bits we can address the fragility then.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Acked-by: Auke Kok <auke-jan.h.kok@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-03-12 16:31:50 -07:00
Eric W. Biederman
58e0543e8f [PATCH] msi: support masking msi irqs without a mask bit
For devices that do not support msi-x we only support 1 interrupt.  Therefore
we can disable that one interrupt by disabling the msi capability itself.  If
we leave the intx interrupts disabled while we have the msi capability
disabled no interrupts should be delivered from that device.

Devices with just the minimal msi support (and thus hitting this code path)
include things like the intel e1000 nic, so it looks like is going to be a
fairly common case and thus important to get right.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Michael Ellerman <michael@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-03-05 07:57:50 -08:00
Eric W. Biederman
b1cbf4e4dd [PATCH] msi: fix up the msi enable/disable logic
enable/disable_msi_mode have several side effects which keeps them from being
generally useful.  So this patch replaces them with with two much more
targeted functions: msi_set_enable and msix_set_enable.

This patch makes pci_dev->msi_enabled and pci_dev->msix_enabled the definitive
way to test if linux has enabled the msi capability, and has the appropriate
msi data structures set up.

This patch ensures that while writing the msi messages in save/restore and
during device initialization we have the msi capability disabled so we don't
get into races.  The pci spec requires that we do not have the msi capability
enabled and the msi messages unmasked while we write the messages.  Completely
disabling the capability is overkill but it is easy :)

Care has been taken so we never have both a msi capability and intx enabled
simultaneously.  We haven't run into a problem yet but better safe then sorry.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Michael Ellerman <michael@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-03-05 07:57:50 -08:00
Eric W. Biederman
f5f2b13129 [PATCH] msi: sanely support hardware level msi disabling
In some cases when we are not using msi we need a way to ensure that the
hardware does not have an msi capability enabled.  Currently the code has been
calling disable_msi_mode to try and achieve that.  However disable_msi_mode
has several other side effects and is only available when msi support is
compiled in so it isn't really appropriate.

Instead this patch implements pci_msi_off which disables all msi and msix
capabilities unconditionally with no additional side effects.

pci_disable_device was redundantly clearing the bus master enable flag and
clearing the msi enable bit.  A device that is not allowed to perform bus
mastering operations cannot generate intx or msi interrupt messages as those
are essentially a special case of dma, and require bus mastering.  So the call
in pci_disable_device to disable msi capabilities was redundant.

quirk_pcie_pxh also called disable_msi_mode and is updated to use pci_msi_off.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Michael Ellerman <michael@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-03-05 07:57:50 -08:00
Eric W. Biederman
f7feaca77d msi: Make MSI useable more architectures
The arch hooks arch_setup_msi_irq and arch_teardown_msi_irq are now
responsible for allocating and freeing the linux irq in addition to
setting up the the linux irq to work with the interrupt.

arch_setup_msi_irq now takes a pci_device and a msi_desc and returns
an irq.

With this change in place this code should be useable by all platforms
except those that won't let the OS touch the hardware like ppc RTAS.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-02-07 15:50:08 -08:00
Eric W. Biederman
5b912c108c msi: Kill the msi_desc array.
We need to be able to get from an irq number to a struct msi_desc.
The msi_desc array in msi.c had several short comings the big one was
that it could not be used outside of msi.c.  Using irq_data in struct
irq_desc almost worked except on some architectures irq_data needs to
be used for something else.

So this patch adds a msi_desc pointer to irq_desc, adds the appropriate
wrappers and changes all of the msi code to use them.

The dynamic_irq_init/cleanup code was tweaked to ensure the new
field is left in a well defined state.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-02-07 15:50:08 -08:00
Eric W. Biederman
1c659d61cf msi: Remove attach_msi_entry.
The attach_msi_entry has been reduced to a single simple assignment,
so for simplicity remove the abstraction and directory perform the
assignment.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-02-07 15:50:08 -08:00
Eric W. Biederman
866a8c87c4 msi: Fix msi_remove_pci_irq_vectors.
Since msi_remove_pci_irq_vectors is designed to be called during
hotplug remove it is actively wrong to query the hardware and expect
meaningful results back.

To that end remove the pci_find_capability calls.  Testing
dev->msi_enabled and dev->msix_enabled gives us all of the information
we need.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-02-07 15:50:07 -08:00
Eric W. Biederman
d40f540ce6 msi: Remove msi_lock.
With the removal of msi_lookup_irq all of the functions using msi_lock
operated on a single device and none of them could reasonably be
called on that device at the same time. 

Since what little synchronization that needs to happen needs to happen
outside of the msi functions, msi_lock could never be contended and as
such is useless and just complicates the code.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-02-07 15:50:07 -08:00
Eric W. Biederman
ded86d8d37 msi: Kill msi_lookup_irq
The function msi_lookup_irq was horrible.  As a side effect of running
it changed dev->irq, and then the callers would need to change it
back.  In addition it does a global scan through all of the irqs,
which seems to be the sole justification of the msi_lock.

To remove the neede for msi_lookup_irq I added first_msi_irq to struct
pci_dev.  Then depending on the context I replaced msi_lookup_irq with
dev->first_msi_irq, dev->msi_enabled, or dev->msix_enabled.

msi_enabled and msix_enabled were already present in pci_dev for other
reasons.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-02-07 15:50:07 -08:00
Michael Ellerman
8fed4b6523 MSI: Combine pci_(save|restore)_msi/msix_state
The PCI save/restore code doesn't need to care about MSI vs MSI-X, all
it really wants is to say "save/restore all MSI(-X) info for this device".

This is borne out in the code, we call the MSI and MSI-X save routines
side by side, and similarly with the restore routines.

So combine the MSI/MSI-X routines into pci_save_msi_state() and
pci_restore_msi_state(). It is up to those routines to decide what state
needs to be saved.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-02-07 15:50:07 -08:00
Michael Ellerman
0fcfdabbdb MSI: Remove pci_scan_msi_device()
pci_scan_msi_device() doesn't do anything anymore, so remove it.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-02-07 15:50:07 -08:00
Michael Ellerman
88187dfa4d MSI: Replace pci_msi_quirk with calls to pci_no_msi()
I don't see any reason why we need pci_msi_quirk, quirk code can just
call pci_no_msi() instead.

Remove the check of pci_msi_quirk in msi_init(). This is safe as all
calls to msi_init() are protected by calls to pci_msi_supported(),
which checks pci_msi_enable, which is disabled by pci_no_msi().

The pci_disable_msi routines didn't check pci_msi_quirk, only
pci_msi_enable, but as far as I can see that was a bug not a feature.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-02-07 15:50:06 -08:00