Commit Graph

473 Commits

Author SHA1 Message Date
Yinghai Lu
0f1103e40f x86/PCI: fix unused variable warning in amd_bus.c
Fix this warning:

  arch/x86/pci/amd_bus.c: In function 'early_fill_mp_bus_info':
  arch/x86/pci/amd_bus.c:56:6: warning: unused variable 'j' [-Wunused-variable]

introduced by commit d28e5ac2a0 ("x86/PCI: dynamically allocate
pci_root_info for native host bridge drivers").

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2012-05-01 17:25:18 -06:00
Yinghai Lu
c57ca65a6e x86/PCI: merge pcibios_scan_root() and pci_scan_bus_on_node()
pcibios_scan_root() and pci_scan_bus_on_node() were almost identical,
so this patch merges them.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2012-04-30 14:52:43 -06:00
Yinghai Lu
d28e5ac2a0 x86/PCI: dynamically allocate pci_root_info for native host bridge drivers
This dynamically allocates struct pci_root_info instead of using a
static array.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2012-04-30 14:52:43 -06:00
Yinghai Lu
35cb05e5bd x86/PCI: embed pci_sysdata into pci_root_info on ACPI path
Embed the x86 struct pci_sysdata in the struct pci_root_info so it
will be automatically freed in the remove path.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2012-04-30 14:52:43 -06:00
Yinghai Lu
fe05725ff9 x86/PCI: embed name into pci_root_info struct
We now keep the pci_root_info struct for the entire lifetime of the
host bridge, so just embed the name in the struct rather than
allocating it separately.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2012-04-30 14:52:43 -06:00
Yinghai Lu
fd3b0c1ea4 x86/PCI: add host bridge resource release for _CRS path
1. Allocate pci_root_info instead of using stack.  We need to pass around
   info for release function.
2. Add release_pci_root_info
3. Set x86 host bridge release function to make sure root bridge
   related resources get freed during root bus removal.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2012-04-30 14:52:43 -06:00
Yinghai Lu
9a03d28d94 x86/PCI: refactor get_current_resources()
Rename get_current_resources() to probe_pci_root_info.

1. Remove resource list head from pci_root_info
2. Make get_current_resources() not pass resources
3. Rename get_current_resources() to probe_pci_root_info()

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2012-04-30 14:52:43 -06:00
Yinghai Lu
baa495d9de x86/PCI: fix memleak with get_current_resources()
In pci_scan_acpi_root(), when pci_use_crs is set, get_current_resources()
is used to get pci_root_info, and it will allocate name and resource array.

Later if pci_create_root_bus() can not create bus (could be already
there...) it will only free bus res list, but the name and res array is not
freed.

Let get_current_resource() take info pointer instead of using local info.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2012-04-30 13:52:17 -06:00
Linus Torvalds
475c77edf8 Merge branch 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci
Pull PCI changes (including maintainer change) from Jesse Barnes:
 "This pull has some good cleanups from Bjorn and Yinghai, as well as
  some more code from Yinghai to better handle resource re-allocation
  when enabled.

  There's also a new initcall_debug feature from Arjan which will print
  out quirk timing information to help identify slow quirks for fixing
  or refinement (Yinghai sent in a few patches to do just that once the
  new debug code landed).

  Beyond that, I'm handing off PCI maintainership to Bjorn Helgaas.
  He's been a core PCI and Linux contributor for some time now, and has
  kindly volunteered to take over.  I just don't feel I have the time
  for PCI review and work that it deserves lately (I've taken on some
  other projects), and haven't been as responsive lately as I'd like, so
  I approached Bjorn asking if he'd like to manage things.  He's going
  to give it a try, and I'm confident he'll do at least as well as I
  have in keeping the tree managed, patches flowing, and keeping things
  stable."

Fix up some fairly trivial conflicts due to other cleanups (mips device
resource fixup cleanups clashing with list handling cleanup, ppc iseries
removal clashing with pci_probe_only cleanup etc)

* 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci: (112 commits)
  PCI: Bjorn gets PCI hotplug too
  PCI: hand PCI maintenance over to Bjorn Helgaas
  unicore32/PCI: move <asm-generic/pci-bridge.h> include to asm/pci.h
  sparc/PCI: convert devtree and arch-probed bus addresses to resource
  powerpc/PCI: allow reallocation on PA Semi
  powerpc/PCI: convert devtree bus addresses to resource
  powerpc/PCI: compute I/O space bus-to-resource offset consistently
  arm/PCI: don't export pci_flags
  PCI: fix bridge I/O window bus-to-resource conversion
  x86/PCI: add spinlock held check to 'pcibios_fwaddrmap_lookup()'
  PCI / PCIe: Introduce command line option to disable ARI
  PCI: make acpihp use __pci_remove_bus_device instead
  PCI: export __pci_remove_bus_device
  PCI: Rename pci_remove_behind_bridge to pci_stop_and_remove_behind_bridge
  PCI: Rename pci_remove_bus_device to pci_stop_and_remove_bus_device
  PCI: print out PCI device info along with duration
  PCI: Move "pci reassigndev resource alignment" out of quirks.c
  PCI: Use class for quirk for usb host controller fixup
  PCI: Use class for quirk for ti816x class fixup
  PCI: Use class for quirk for intel e100 interrupt fixup
  ...
2012-03-23 14:02:12 -07:00
Linus Torvalds
d4c6fa73fe Features:
- PV multiconsole support, so that there can be hvc1, hvc2, etc;
  - P-state and C-state power management driver that uploads said
    power management data to the hypervisor. It also inhibits cpufreq
    scaling drivers to load so that only the hypervisor can make power
    management decisions - fixing a weird perf bug.
  - Function Level Reset (FLR) support in the Xen PCI backend.
 Fixes:
  - Kconfig dependencies for Xen PV keyboard and video
  - Compile warnings and constify fixes
  - Change over to use percpu_xxx instead of this_cpu_xxx
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1.4.11 (GNU/Linux)
 
 iQEcBAABAgAGBQJPZ0qkAAoJEFjIrFwIi8fJjCgH/jeJ39E8ML8DP9tCS2HQnMqM
 uTEjLcqvoJ7sEhHvtBLPeG2p0jyBvOWjLbSc7P8nESBAMPvSYol8L6WqfWrdSU4r
 lHrma2sg9UYzRog5NyxAgkp7bBsBBFOnhVL3Cxb5Ig78cPWzeSWGpqGZ8M/d51Wf
 1iE0tHuU4DpN+fg1SZqPqEm8ecEJ/eSrVTnyTx/Qo2Ak+Zw98SqzX7SV5lo8mudd
 WFL1F2K9FyTNk79ndGhqFt36x6nEbFgMLbmCDWumLuWN6bMd1Uq0wNkCqW4F1h28
 3yqnY+rfQh4y3eXK1B9nttCUTs+/66U5ZWrT6B1IJumGTAIqcWfgeUX/Vn/HVC4=
 =tfMc
 -----END PGP SIGNATURE-----

Merge tag 'stable/for-linus-3.4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen

Pull xen updates from Konrad Rzeszutek Wilk:
 "which has three neat features:

   - PV multiconsole support, so that there can be hvc1, hvc2, etc; This
     can be used in HVM and in PV mode.

   - P-state and C-state power management driver that uploads said power
     management data to the hypervisor.  It also inhibits cpufreq
     scaling drivers to load so that only the hypervisor can make power
     management decisions - fixing a weird perf bug.

     There is one thing in the Kconfig that you won't like: "default y
     if (X86_ACPI_CPUFREQ = y || X86_POWERNOW_K8 = y)" (note, that it
     all depends on CONFIG_XEN which depends on CONFIG_PARAVIRT which by
     default is off).  I've a fix to convert that boolean expression
     into "default m" which I am going to post after the cpufreq git
     pull - as the two patches to make this work depend on a fix in Dave
     Jones's tree.

   - Function Level Reset (FLR) support in the Xen PCI backend.

  Fixes:

   - Kconfig dependencies for Xen PV keyboard and video
   - Compile warnings and constify fixes
   - Change over to use percpu_xxx instead of this_cpu_xxx"

Fix up trivial conflicts in drivers/tty/hvc/hvc_xen.c due to changes to
a removed commit.

* tag 'stable/for-linus-3.4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xen kconfig: relax INPUT_XEN_KBDDEV_FRONTEND deps
  xen/acpi-processor: C and P-state driver that uploads said data to hypervisor.
  xen: constify all instances of "struct attribute_group"
  xen/xenbus: ignore console/0
  hvc_xen: introduce HVC_XEN_FRONTEND
  hvc_xen: implement multiconsole support
  hvc_xen: support PV on HVM consoles
  xenbus: don't free other end details too early
  xen/enlighten: Expose MWAIT and MWAIT_LEAF if hypervisor OKs it.
  xen/setup/pm/acpi: Remove the call to boot_option_idle_override.
  xenbus: address compiler warnings
  xen: use this_cpu_xxx replace percpu_xxx funcs
  xen/pciback: Support pci_reset_function, aka FLR or D3 support.
  pci: Introduce __pci_reset_function_locked to be used when holding device_lock.
  xen: Utilize the restore_msi_irqs hook.
2012-03-22 20:16:14 -07:00
Myron Stowe
63ab387ca0 x86/PCI: add spinlock held check to 'pcibios_fwaddrmap_lookup()'
'pcibios_fwaddrmap_lookup()' is used to maintain FW-assigned BIOS BAR
values for reinstatement when normal resource assignment attempts
fail and must be called with the 'pcibios_fwaddrmap_lock' spinlock
held.

This patch adds a WARN_ON notification if the spinlock is not currently
held by the caller.

Signed-off-by: Myron Stowe <myron.stowe@redhat.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2012-03-02 12:03:58 -08:00
Jonathan Nieder
a97f4f5e52 x86/PCI: do not tie MSI MS-7253 use_crs quirk to BIOS version
Carlos was getting

	WARNING: at drivers/pci/pci.c:118 pci_ioremap_bar+0x24/0x52()

when probing his sound card, and sound did not work.  After adding
pci=use_crs to the kernel command line, no more trouble.

Ok, we can add a quirk.  dmidecode output reveals that this is an MSI
MS-7253, for which we already have a quirk, but the short-sighted
author tied the quirk to a single BIOS version, making it not kick in
on Carlos's machine with BIOS V1.2.  If a later BIOS update makes it
no longer necessary to look at the _CRS info it will still be
harmless, so let's stop trying to guess which versions have and don't
have accurate _CRS tables.

Addresses https://bugtrack.alsa-project.org/alsa-bug/view.php?id=5533
Also see <https://bugzilla.kernel.org/show_bug.cgi?id=42619>.

Reported-by: Carlos Luna <caralu74@gmail.com>
Reviewed-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2012-03-01 10:56:37 -08:00
Jonathan Nieder
8411371709 x86/PCI: use host bridge _CRS info on MSI MS-7253
In the spirit of commit 29cf7a30f8 ("x86/PCI: use host bridge _CRS
info on ASUS M2V-MX SE"), this DMI quirk turns on "pci_use_crs" by
default on a board that needs it.

This fixes boot failures and oopses introduced in 3e3da00c01
("x86/pci: AMD one chain system to use pci read out res").  The quirk
is quite targetted (to a specific board and BIOS version) for two
reasons:

 (1) to emphasize that this method of tackling the problem one quirk
     at a time is a little insane

 (2) to give BIOS vendors an opportunity to use simpler tables and
     allow us to return to generic behavior (whatever that happens to
     be) with a later BIOS update

In other words, I am not at all happy with having quirks like this.
But it is even worse for the kernel not to work out of the box on
these machines, so...

Reference: https://bugzilla.kernel.org/show_bug.cgi?id=42619
Reported-by: Svante Signell <svante.signell@telia.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2012-02-28 11:09:09 -08:00
Yinghai Lu
73e3b590f3 PCI: Use class for quirk for pci_fixup_video
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2012-02-24 14:34:46 -08:00
Yinghai Lu
4082cf2d7b PCI: Use class quirk for intel fix_transparent_bridge
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2012-02-24 14:34:45 -08:00
Alan Cox
823806ff6b x86/mrst/pci: avoid SoC fixups on non-SoC platforms
The PCI fixups get executed based upon whether they are linked in. We need
to avoid executing them if we boot a dual SoC/PC type kernel on a PC class
system.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2012-02-23 12:33:27 -08:00
Jacob Pan
8ed3087280 x86/mrst/pci: v4l/atomisp: treat atomisp as real pci device
ATOMISP on Medfield is a real PCI device which should be handled differently
than the fake PCI devices on south complex. PCI type 1 access is used for
accessing config space this also has other impact such as PM D3 delay. There
shouldn't be any need for reading base address from IUNIT via msg bus.

Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2012-02-23 12:32:05 -08:00
Jacob Pan
990a30c50c x86/mrst/pci: assign d3_delay to 0 for Langwell devices
Langwell devices are not true pci devices, they are not subject to the 10 ms
d3 to d0 delay required by pci spec. This patch assigns d3_delay to 0 for all
langwell pci devices.

We can also power off devices that are not really used by the OS

Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2012-02-23 12:31:36 -08:00
Yinghai Lu
1cc1c96c16 PCI: fix memleak when ACPI _CRS is not used.
warning:
unreferenced object 0xffff8801f6914200 (size 512):
  comm "swapper/0", pid 1, jiffies 4294893643 (age 2664.644s)
  hex dump (first 32 bytes):
    00 00 c0 fe 00 00 00 00 ff ff ff ff 00 00 00 00  ................
    60 58 2f f6 03 88 ff ff 00 02 00 00 00 00 00 00  `X/.............
  backtrace:
    [<ffffffff81c2408c>] kmemleak_alloc+0x26/0x43
    [<ffffffff8113764f>] __kmalloc+0x121/0x183
    [<ffffffff81ca8d93>] get_current_resources+0x5a/0xc6
    [<ffffffff81c5bedd>] pci_acpi_scan_root+0x13c/0x21c
    [<ffffffff81c2a745>] acpi_pci_root_add+0x1e1/0x421
    [<ffffffff81408f50>] acpi_device_probe+0x50/0x190
    [<ffffffff8149edc7>] really_probe+0x99/0x126
    [<ffffffff8149ef83>] driver_probe_device+0x3b/0x56
    [<ffffffff8149effd>] __driver_attach+0x5f/0x82
    [<ffffffff8149d860>] bus_for_each_dev+0x5c/0x88
    [<ffffffff8149eb87>] driver_attach+0x1e/0x20
    [<ffffffff8149e7cc>] bus_add_driver+0xca/0x21d
    [<ffffffff8149f47b>] driver_register+0x91/0xfe
    [<ffffffff81409d09>] acpi_bus_register_driver+0x43/0x45
    [<ffffffff8278bdc9>] acpi_pci_root_init+0x20/0x28
    [<ffffffff810001e7>] do_one_initcall+0x57/0x134

The system has _CRS for root buses, but they are not used because the machine
date is before the cutoff date for _CRS usage.

Try to free those unused resource arrays and names.

Reviewed-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2012-02-23 12:01:33 -08:00
Bjorn Helgaas
316d86fe86 x86/PCI: don't fall back to defaults if _CRS has no apertures
Host bridges that lead to things like the Uncore need not have any
I/O port or MMIO apertures.  For example, in this case:

    ACPI: PCI Root Bridge [UNC1] (domain 0000 [bus ff])
    PCI: root bus ff: using default resources
    PCI host bridge to bus 0000:ff
    pci_bus 0000:ff: root bus resource [io  0x0000-0xffff]
    pci_bus 0000:ff: root bus resource [mem 0x00000000-0x3fffffffffff]

we should not pretend those default resources are available on bus ff.

CC: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2012-02-14 08:44:49 -08:00
Myron Stowe
6535943fbf x86/PCI: Convert maintaining FW-assigned BIOS BAR values to use a list
This patch converts the underlying maintenance aspects of FW-assigned
BIOS BAR values from a statically allocated array within struct pci_dev
to a list of temporary, stand alone, entries.

Signed-off-by: Myron Stowe <myron.stowe@redhat.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2012-02-14 08:44:46 -08:00
Myron Stowe
925845bd49 x86/PCI: Infrastructure to maintain a list of FW-assigned BIOS BAR values
Commit 58c84eda07 introduced functionality to try and reinstate the
original BIOS BAR addresses of a PCI device when normal resource
assignment attempts fail.  To keep track of the BIOS BAR addresses,
struct pci_dev was augmented with an array to hold the BAR addresses
of the PCI device: 'resource_size_t fw_addr[DEVICE_COUNT_RESOURCE]'.

The reinstatement of BAR addresses is an uncommon event leaving the
'fw_addr' array unused under normal circumstances.  This functionality
is also currently architecture specific with an implementation limited
to x86.  As the use of struct pci_dev is so prevalent, having the
'fw_addr' array residing within such seems somewhat wasteful.

This patch introduces a stand alone data structure and interfacing
routines for maintaining a list of FW-assigned BIOS BAR value entries.

Signed-off-by: Myron Stowe <myron.stowe@redhat.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2012-02-14 08:44:46 -08:00
Stefano Stabellini
207d543f47 xen pvhvm: do not remap pirqs onto evtchns if !xen_have_vector_callback
CC: stable@kernel.org #2.6.37 and onwards
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-02-03 16:06:27 -05:00
Tang Liang
8605c6844f xen: Utilize the restore_msi_irqs hook.
to make a hypercall to restore the vectors in the MSI/MSI-X
configuration space.

Signed-off-by: Tang Liang <liang.tang@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-01-12 11:55:22 -05:00
Bjorn Helgaas
5cf9a4e69c x86/PCI: build amd_bus.o only when CONFIG_AMD_NB=y
We only need amd_bus.o for AMD systems with PCI.  arch/x86/pci/Makefile
already depends on CONFIG_PCI=y, so this patch just adds the dependency
on CONFIG_AMD_NB.

Cc: Yinghai Lu <yinghai@kernel.org>
Cc: stable@kernel.org	# 2.6.34+ (needs adjustment for k8 -> amd rename)
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-12 07:54:18 -08:00
Linus Torvalds
9fc5c3e323 Merge branch 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
* 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/intel config: Fix the APB_TIMER selection
  x86/mrst: Add additional debug prints for pb_keys
  x86/intel config: Revamp configuration to allow for Moorestown and Medfield
  x86/intel/scu/ipc: Match the changes in the x86 configuration
  x86/apb: Fix configuration constraints
  x86: Fix INTEL_MID silly
  x86/Kconfig: Cyclone-timer depends on x86-summit
  x86: Reduce clock calibration time during slave cpu startup
  x86/config: Revamp configuration for MID devices
  x86/sfi: Kill the IRQ as id hack
2012-01-11 19:13:40 -08:00
Linus Torvalds
7b67e75147 Merge branch 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci
* 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci: (80 commits)
  x86/PCI: Expand the x86_msi_ops to have a restore MSIs.
  PCI: Increase resource array mask bit size in pcim_iomap_regions()
  PCI: DEVICE_COUNT_RESOURCE should be equal to PCI_NUM_RESOURCES
  PCI: pci_ids: add device ids for STA2X11 device (aka ConneXT)
  PNP: work around Dell 1536/1546 BIOS MMCONFIG bug that breaks USB
  x86/PCI: amd: factor out MMCONFIG discovery
  PCI: Enable ATS at the device state restore
  PCI: msi: fix imbalanced refcount of msi irq sysfs objects
  PCI: kconfig: English typo in pci/pcie/Kconfig
  PCI/PM/Runtime: make PCI traces quieter
  PCI: remove pci_create_bus()
  xtensa/PCI: convert to pci_scan_root_bus() for correct root bus resources
  x86/PCI: convert to pci_create_root_bus() and pci_scan_root_bus()
  x86/PCI: use pci_scan_bus() instead of pci_scan_bus_parented()
  x86/PCI: read Broadcom CNB20LE host bridge info before PCI scan
  sparc32, leon/PCI: convert to pci_scan_root_bus() for correct root bus resources
  sparc/PCI: convert to pci_create_root_bus()
  sh/PCI: convert to pci_scan_root_bus() for correct root bus resources
  powerpc/PCI: convert to pci_create_root_bus()
  powerpc/PCI: split PHB part out of pcibios_map_io_space()
  ...

Fix up conflicts in drivers/pci/msi.c and include/linux/pci_regs.h due
to the same patches being applied in other branches.
2012-01-11 18:50:26 -08:00
Bjorn Helgaas
24d25dbfa6 x86/PCI: amd: factor out MMCONFIG discovery
This factors out the AMD native MMCONFIG discovery so we can use it
outside amd_bus.c.

amd_bus.c reads AMD MSRs so it can remove the MMCONFIG area from the
PCI resources.  We may also need the MMCONFIG information to work
around BIOS defects in the ACPI MCFG table.

Cc: Borislav Petkov <borislav.petkov@amd.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: stable@kernel.org       # 2.6.34+
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2012-01-06 12:11:19 -08:00
Bjorn Helgaas
2cd6975a4f x86/PCI: convert to pci_create_root_bus() and pci_scan_root_bus()
x86 has two kinds of PCI root bus scanning:

(1) ACPI-based, using _CRS resources.  This used pci_create_bus(), not
    pci_scan_bus(), because ACPI hotplug needed to split the
    pci_bus_add_devices() into a separate host bridge .start() method.

    This patch parses the _CRS resources earlier, so we can build a list of
    resources and pass it to pci_create_root_bus().

    Note that as before, we parse the _CRS even if we aren't going to use
    it so we can print it for debugging purposes.

(2) All other, which used either default resources (ioport_resource and
    iomem_resource) or information read from the hardware via amd_bus.c or
    similar.  This used pci_scan_bus().

    This patch converts x86_pci_root_bus_res_quirks() (previously called
    from pcibios_fixup_bus()) to x86_pci_root_bus_resources(), which builds
    a list of resources before we call pci_scan_root_bus().

    We also use x86_pci_root_bus_resources() if we have ACPI but are
    ignoring _CRS.

CC: Yinghai Lu <yinghai.lu@oracle.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2012-01-06 12:11:14 -08:00
Bjorn Helgaas
46fbade05c x86/PCI: use pci_scan_bus() instead of pci_scan_bus_parented()
This doesn't change any functionality, but it makes a subsequent patch
slightly simpler.

pci_scan_bus(NULL, ...) and pci_scan_bus_parented() are identical except
that pci_scan_bus() also calls pci_bus_add_devices():

  pci_scan_bus_parented
    pci_create_bus
    pci_scan_child_bus

  pci_scan_bus
    pci_create_bus
    pci_scan_child_bus
    pci_bus_add_devices

All callers of pcibios_scan_root() call pci_bus_add_devices() explicitly,
and we don't pass a parent device, so we might as well use pci_scan_bus().

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2012-01-06 12:11:13 -08:00
Bjorn Helgaas
6361d72b04 x86/PCI: read Broadcom CNB20LE host bridge info before PCI scan
We currently read the CNB20LE aperture information in a PCI quirk,
which happens after we've already created the root bus.  This patch
changes it to read the apertures earlier so we can create the root
bus with the correct resources.

I believe the CNB20LE lives at "pci 0000:00:00" based on
https://lkml.org/lkml/2010/8/13/220

CC: Ira W. Snyder <iws@ovro.caltech.edu>
CC: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2012-01-06 12:11:12 -08:00
Andreas Herrmann
ca3671a833 x86/PCI: amd: Kill misleading message about enablement of IO access to PCI ECS]
Commit 24d9b70b8c (x86: Use PCI method
for enabling AMD extended config space before MSR method) added a
message when IO access to PCI ECS was enabled via access to the NB_CFG
PCI register.  This can lead to a bogus message like

[    0.365177] Extended Config Space enabled on 0 nodes

which is misleading because IO ECS access is subsequently enabled for
AMD CPUs (that support this) by modifying the corresponding NB_CFG
MSR.

Furthermore it's not "Extended Config Space" that is enabled by this
register setting. It's the IO access that is enabled for extended
configruation space.

IMHO the ambiguous message needs to be cancelled.

Cc: Jan Beulich <jbeulich@novell.com>
Cc: Robert Richter <robert.richter@amd.com>
Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2012-01-06 12:10:48 -08:00
Myron Stowe
b9a276ad26 PCI: x86: use generic pcibios_set_master()
This patch removes x86's architecture-specific 'pcibios_set_master()'
routine and lets the default PCI core based implementation handle PCI
device 'latency timer' setup.

No functional change.

Signed-off-by: Myron Stowe <myron.stowe@redhat.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2012-01-06 12:10:46 -08:00
Myron Stowe
96c5590058 PCI: Pull PCI 'latency timer' setup up into the core
The 'latency timer' of PCI devices, both Type 0 and Type 1,
is setup in architecture-specific code [see: 'pcibios_set_master()'].
There are two approaches being taken by all the architectures - check
if the 'latency timer' is currently set between 16 and 255 and if not
bring it within bounds, or, do nothing (and then there is the
gratuitously different PA-RISC implementation).

There is nothing architecture-specific about PCI's 'latency timer' so
this patch pulls its setup functionality up into the PCI core by
creating a generic 'pcibios_set_master()' function using the '__weak'
attribute which can be used by all architectures as a default which,
if necessary, can then be over-ridden by architecture-specific code.

No functional change.

Signed-off-by: Myron Stowe <myron.stowe@redhat.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2012-01-06 12:10:42 -08:00
Gary Hade
ae5cd86455 x86/PCI: Ignore CPU non-addressable _CRS reserved memory resources
This assures that a _CRS reserved host bridge window or window region is
not used if it is not addressable by the CPU.  The new code either trims
the window to exclude the non-addressable portion or totally ignores the
window if the entire window is non-addressable.

The current code has been shown to be problematic with 32-bit non-PAE
kernels on systems where _CRS reserves resources above 4GB.

Signed-off-by: Gary Hade <garyhade@us.ibm.com>
Reviewed-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Thomas Renninger <trenn@novell.com>
Cc: linux-kernel@vger.kernel.org
Cc: stable@kernel.org
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2012-01-06 12:10:32 -08:00
Dave Jones
8b6a5af92c PCI: Add Thinkpad SL510 to pci=nocrs blacklist
Enabling CRS by default breaks suspend on the Thinkpad SL510.
Details in https://bugzilla.redhat.com/show_bug.cgi?id=769657

Reported-by: Stefan Kirrmann <stefan.kirrmann@gmail.com>
Signed-off-by: Dave Jones <davej@redhat.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2012-01-06 12:09:54 -08:00
Dave Jones
e702781fa8 PCI: Add Dell Studio 1557 to pci=nocrs blacklist
The Dell Studio 1557 also doesn't suspend correctly when CRS is enabled.
Details at https://bugzilla.redhat.com/show_bug.cgi?id=769657

Reported-by: Gregory S. Hoerner <ghoerner@transcendingthought.com>
Signed-off-by: Dave Jones <davej@redhat.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2012-01-06 12:09:41 -08:00
Dave Jones
28c3c05d33 PCI: add set_nouse_crs for use by a pci=nocrs blacklist
Some machines don't boot unless passed pci=nocrs.
(See https://bugzilla.redhat.com/show_bug.cgi?id=770308 for details of
  one report. Waiting on dmidecode output for others).

Currently there is a DMI whitelist, even though the default is on.

v2: drop the 1536 blacklist entry, superceded by the PNP/MMCONFIG changes from
    Bjorn

Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Dave Jones <davej@redhat.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2012-01-06 12:08:44 -08:00
Alan Cox
933b9463a0 x86/intel config: Revamp configuration to allow for Moorestown and Medfield
This sets all up the other bits that need to be INTEL_MID
specific rather than Moorestown specific.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Link: http://lkml.kernel.org/r/20111217174318.7207.91543.stgit@bob.linux.org.uk
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-18 09:17:02 +01:00
Wang YanQing
819a693b5a typo fixes: aera -> area, exntension -> extension
One printk and one comment typo fix.

Signed-off-by: Wang YanQing <udknight@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2011-12-09 15:22:07 +01:00
Paul Gortmaker
69c60c88ee x86: Fix files explicitly requiring export.h for EXPORT_SYMBOL/THIS_MODULE
These files were implicitly getting EXPORT_SYMBOL via device.h
which was including module.h, but that will be fixed up shortly.

By fixing these now, we can avoid seeing things like:

arch/x86/kernel/rtc.c:29: warning: type defaults to ‘int’ in declaration of ‘EXPORT_SYMBOL’
arch/x86/kernel/pci-dma.c:20: warning: type defaults to ‘int’ in declaration of ‘EXPORT_SYMBOL’
arch/x86/kernel/e820.c:69: warning: type defaults to ‘int’ in declaration of ‘EXPORT_SYMBOL_GPL’

[ with input from Randy Dunlap <rdunlap@xenotime.net> and also
  from Stephen Rothwell <sfr@canb.auug.org.au> ]

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-10-31 19:30:35 -04:00
Linus Torvalds
0e59e7e7fe Merge branch 'next-rebase' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci
* 'next-rebase' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci:
  PCI: Clean-up MPS debug output
  pci: Clamp pcie_set_readrq() when using "performance" settings
  PCI: enable MPS "performance" setting to properly handle bridge MPS
  PCI: Workaround for Intel MPS errata
  PCI: Add support for PASID capability
  PCI: Add implementation for PRI capability
  PCI: Export ATS functions to modules
  PCI: Move ATS implementation into own file
  PCI / PM: Remove unnecessary error variable from acpi_dev_run_wake()
  PCI hotplug: acpiphp: Prevent deadlock on PCI-to-PCI bridge remove
  PCI / PM: Extend PME polling to all PCI devices
  PCI quirk: mmc: Always check for lower base frequency quirk for Ricoh 1180:e823
  PCI: Make pci_setup_bridge() non-static for use by arch code
  x86: constify PCI raw ops structures
  PCI: Add quirk for known incorrect MPSS
  PCI: Add Solarflare vendor ID and SFC4000 device IDs
2011-10-28 14:20:44 -07:00
Linus Torvalds
04a8752485 Merge branches 'stable/drivers-3.2', 'stable/drivers.bugfixes-3.2' and 'stable/pci.fixes-3.2' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen
* 'stable/drivers-3.2' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xenbus: don't rely on xen_initial_domain to detect local xenstore
  xenbus: Fix loopback event channel assuming domain 0
  xen/pv-on-hvm:kexec: Fix implicit declaration of function 'xen_hvm_domain'
  xen/pv-on-hvm kexec: add xs_reset_watches to shutdown watches from old kernel
  xen/pv-on-hvm kexec: update xs_wire.h:xsd_sockmsg_type from xen-unstable
  xen/pv-on-hvm kexec+kdump: reset PV devices in kexec or crash kernel
  xen/pv-on-hvm kexec: rebind virqs to existing eventchannel ports
  xen/pv-on-hvm kexec: prevent crash in xenwatch_thread() when stale watch events arrive

* 'stable/drivers.bugfixes-3.2' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xen/pciback: Check if the device is found instead of blindly assuming so.
  xen/pciback: Do not dereference psdev during printk when it is NULL.
  xen: remove XEN_PLATFORM_PCI config option
  xen: XEN_PVHVM depends on PCI
  xen/pciback: double lock typo
  xen/pciback: use mutex rather than spinlock in vpci backend
  xen/pciback: Use mutexes when working with Xenbus state transitions.
  xen/pciback: miscellaneous adjustments
  xen/pciback: use mutex rather than spinlock in passthrough backend
  xen/pciback: use resource_size()

* 'stable/pci.fixes-3.2' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xen/pci: support multi-segment systems
  xen-swiotlb: When doing coherent alloc/dealloc check before swizzling the MFNs.
  xen/pci: make bus notifier handler return sane values
  xen-swiotlb: fix printk and panic args
  xen-swiotlb: Fix wrong panic.
  xen-swiotlb: Retry up three times to allocate Xen-SWIOTLB
  xen-pcifront: Update warning comment to use 'e820_host' option.
2011-10-25 09:19:36 +02:00
Linus Torvalds
31018acd4c Merge branches 'stable/bug.fixes-3.2' and 'stable/mmu.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen
* 'stable/bug.fixes-3.2' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xen/p2m/debugfs: Make type_name more obvious.
  xen/p2m/debugfs: Fix potential pointer exception.
  xen/enlighten: Fix compile warnings and set cx to known value.
  xen/xenbus: Remove the unnecessary check.
  xen/irq: If we fail during msi_capability_init return proper error code.
  xen/events: Don't check the info for NULL as it is already done.
  xen/events: BUG() when we can't allocate our event->irq array.

* 'stable/mmu.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xen: Fix selfballooning and ensure it doesn't go too far
  xen/gntdev: Fix sleep-inside-spinlock
  xen: modify kernel mappings corresponding to granted pages
  xen: add an "highmem" parameter to alloc_xenballooned_pages
  xen/p2m: Use SetPagePrivate and its friends for M2P overrides.
  xen/p2m: Make debug/xen/mmu/p2m visible again.
  Revert "xen/debug: WARN_ON when identity PFN has no _PAGE_IOMAP flag set."
2011-10-25 09:17:47 +02:00
Konrad Rzeszutek Wilk
e6599225db xen/irq: If we fail during msi_capability_init return proper error code.
There are three different modes: PV, HVM, and initial domain 0. In all
the cases we would return -1 for failure instead of a proper error code.
Fix this by propagating the error code from the generic IRQ code.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-10-19 17:03:28 -04:00
Jan Beulich
72da0b07b1 x86: constify PCI raw ops structures
As with any other such change, the goal is to prevent inadvertent
writes to these structures (assuming DEBUG_RODATA is enabled), and to
separate data (possibly frequently) written to from such never getting
modified.

Reviewed-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2011-10-14 09:05:28 -07:00
Paul Menzel
29cf7a30f8 x86/PCI: use host bridge _CRS info on ASUS M2V-MX SE
In summary, this DMI quirk uses the _CRS info by default for the ASUS
M2V-MX SE by turning on `pci=use_crs` and is similar to the quirk
added by commit 2491762cfb ("x86/PCI: use host bridge _CRS info on
ASRock ALiveSATA2-GLAN") whose commit message should be read for further
information.

Since commit 3e3da00c01 ("x86/pci: AMD one chain system to use pci
read out res") Linux gives the following oops:

    parport0: PC-style at 0x378, irq 7 [PCSPP,TRISTATE]
    HDA Intel 0000:20:01.0: PCI INT A -> GSI 17 (level, low) -> IRQ 17
    HDA Intel 0000:20:01.0: setting latency timer to 64
    BUG: unable to handle kernel paging request at ffffc90011c08000
    IP: [<ffffffffa0578402>] azx_probe+0x3ad/0x86b [snd_hda_intel]
    PGD 13781a067 PUD 13781b067 PMD 1300ba067 PTE 800000fd00000173
    Oops: 0009 [#1] SMP
    last sysfs file: /sys/module/snd_pcm/initstate
    CPU 0
    Modules linked in: snd_hda_intel(+) snd_hda_codec snd_hwdep snd_pcm_oss snd_mixer_oss snd_pcm snd_seq_midi snd_rawmidi snd_seq_midi_event tpm_tis tpm snd_seq tpm_bios psmouse parport_pc snd_timer snd_seq_device parport processor evdev snd i2c_viapro thermal_sys amd64_edac_mod k8temp i2c_core soundcore shpchp pcspkr serio_raw asus_atk0110 pci_hotplug edac_core button snd_page_alloc edac_mce_amd ext3 jbd mbcache sha256_generic cryptd aes_x86_64 aes_generic cbc dm_crypt dm_mod raid1 md_mod usbhid hid sg sd_mod crc_t10dif sr_mod cdrom ata_generic uhci_hcd sata_via pata_via libata ehci_hcd usbcore scsi_mod via_rhine mii nls_base [last unloaded: scsi_wait_scan]
    Pid: 1153, comm: work_for_cpu Not tainted 2.6.37-1-amd64 #1 M2V-MX SE/System Product Name
    RIP: 0010:[<ffffffffa0578402>]  [<ffffffffa0578402>] azx_probe+0x3ad/0x86b [snd_hda_intel]
    RSP: 0018:ffff88013153fe50  EFLAGS: 00010286
    RAX: ffffc90011c08000 RBX: ffff88013029ec00 RCX: 0000000000000006
    RDX: 0000000000000000 RSI: 0000000000000246 RDI: 0000000000000246
    RBP: ffff88013341d000 R08: 0000000000000000 R09: 0000000000000040
    R10: 0000000000000286 R11: 0000000000003731 R12: ffff88013029c400
    R13: 0000000000000000 R14: 0000000000000000 R15: ffff88013341d090
    FS:  0000000000000000(0000) GS:ffff8800bfc00000(0000) knlGS:00000000f7610ab0
    CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
    CR2: ffffc90011c08000 CR3: 0000000132f57000 CR4: 00000000000006f0
    DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
    DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
    Process work_for_cpu (pid: 1153, threadinfo ffff88013153e000, task ffff8801303c86c0)
    Stack:
     0000000000000005 ffffffff8123ad65 00000000000136c0 ffff88013029c400
     ffff8801303c8998 ffff88013341d000 ffff88013341d090 ffff8801322d9dc8
     ffff88013341d208 0000000000000000 0000000000000000 ffffffff811ad232
    Call Trace:
     [<ffffffff8123ad65>] ? __pm_runtime_set_status+0x162/0x186
     [<ffffffff811ad232>] ? local_pci_probe+0x49/0x92
     [<ffffffff8105afc5>] ? do_work_for_cpu+0x0/0x1b
     [<ffffffff8105afc5>] ? do_work_for_cpu+0x0/0x1b
     [<ffffffff8105afd0>] ? do_work_for_cpu+0xb/0x1b
     [<ffffffff8105fd3f>] ? kthread+0x7a/0x82
     [<ffffffff8100a824>] ? kernel_thread_helper+0x4/0x10
     [<ffffffff8105fcc5>] ? kthread+0x0/0x82
     [<ffffffff8100a820>] ? kernel_thread_helper+0x0/0x10
    Code: f4 01 00 00 ef 31 f6 48 89 df e8 29 dd ff ff 85 c0 0f 88 2b 03 00 00 48 89 ef e8 b4 39 c3 e0 8b 7b 40 e8 fc 9d b1 e0 48 8b 43 38 <66> 8b 10 66 89 14 24 8b 43 14 83 e8 03 83 f8 01 77 32 31 d2 be
    RIP  [<ffffffffa0578402>] azx_probe+0x3ad/0x86b [snd_hda_intel]
     RSP <ffff88013153fe50>
    CR2: ffffc90011c08000
    ---[ end trace 8d1f3ebc136437fd ]---

Trusting the ACPI _CRS information (`pci=use_crs`) fixes this problem.

    $ dmesg | grep -i crs # with the quirk
    PCI: Using host bridge windows from ACPI; if necessary, use "pci=nocrs" and report a bug

The match has to be against the DMI board entries though since the vendor entries are not populated.

    DMI: System manufacturer System Product Name/M2V-MX SE, BIOS 0304    10/30/2007

This quirk should be removed when `pci=use_crs` is enabled for machines
from 2006 or earlier or some other solution is implemented.

Using coreboot [1] with this board the problem does not exist but this
quirk also does not affect it either. To be safe though the check is
tightened to only take effect when the BIOS from American Megatrends is
used.

        15:13 < ruik> but coreboot does not need that
        15:13 < ruik> because i have there only one root bus
        15:13 < ruik> the audio is behind a bridge

        $ sudo dmidecode
        BIOS Information
                Vendor: American Megatrends Inc.
                Version: 0304
                Release Date: 10/30/2007

[1] http://www.coreboot.org/

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=30552

Cc: stable@kernel.org (2.6.34)
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: x86@kernel.org
Signed-off-by: Paul Menzel <paulepanter@users.sourceforge.net>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-10-06 16:10:37 -07:00
Jan Beulich
55e901fc1f xen/pci: support multi-segment systems
Now that the hypercall interface changes are in -unstable, make the
kernel side code not ignore the segment (aka domain) number anymore
(which results in pretty odd behavior on such systems). Rather, if
only the old interfaces are available, don't call them for devices on
non-zero segments at all.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
[v1: Edited git description]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-09-22 16:23:46 -04:00
Shyam Iyer
5307f6d5fb Fix pointer dereference before call to pcie_bus_configure_settings
Commit b03e7495a8 ("PCI: Set PCI-E Max Payload Size on fabric")
introduced a potential NULL pointer dereference in calls to
pcie_bus_configure_settings due to attempts to access pci_bus self
variables when the self pointer is NULL.

To correct this, verify that the self pointer in pci_bus is non-NULL
before dereferencing it.

Reported-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Shyam Iyer <shyam_iyer@dell.com>
Signed-off-by: Jon Mason <mason@myri.com>
Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-09-09 19:49:58 -07:00
Jon Mason
b03e7495a8 PCI: Set PCI-E Max Payload Size on fabric
On a given PCI-E fabric, each device, bridge, and root port can have a
different PCI-E maximum payload size.  There is a sizable performance
boost for having the largest possible maximum payload size on each PCI-E
device.  However, if improperly configured, fatal bus errors can occur.
Thus, it is important to ensure that PCI-E payloads sends by a device
are never larger than the MPS setting of all devices on the way to the
destination.

This can be achieved two ways:

- A conservative approach is to use the smallest common denominator of
  the entire tree below a root complex for every device on that fabric.

This means for example that having a 128 bytes MPS USB controller on one
leg of a switch will dramatically reduce performances of a video card or
10GE adapter on another leg of that same switch.

It also means that any hierarchy supporting hotplug slots (including
expresscard or thunderbolt I suppose, dbl check that) will have to be
entirely clamped to 128 bytes since we cannot predict what will be
plugged into those slots, and we cannot change the MPS on a "live"
system.

- A more optimal way is possible, if it falls within a couple of
  constraints:
* The top-level host bridge will never generate packets larger than the
  smallest TLP (or if it can be controlled independently from its MPS at
  least)
* The device will never generate packets larger than MPS (which can be
  configured via MRRS)
* No support of direct PCI-E <-> PCI-E transfers between devices without
  some additional code to specifically deal with that case

Then we can use an approach that basically ignores downstream requests
and focuses exclusively on upstream requests. In that case, all we need
to care about is that a device MPS is no larger than its parent MPS,
which allows us to keep all switches/bridges to the max MPS supported by
their parent and eventually the PHB.

In this case, your USB controller would no longer "starve" your 10GE
Ethernet and your hotplug slots won't affect your global MPS.
Additionally, the hotplugged devices themselves can be configured to a
larger MPS up to the value configured in the hotplug bridge.

To choose between the two available options, two PCI kernel boot args
have been added to the PCI calls.  "pcie_bus_safe" will provide the
former behavior, while "pcie_bus_perf" will perform the latter behavior.
By default, the latter behavior is used.

NOTE: due to the location of the enablement, each arch will need to add
calls to this function.  This patch only enables x86.

This patch includes a number of changes recommended by Benjamin
Herrenschmidt.

Tested-by: Jordan_Hargrave@dell.com
Signed-off-by: Jon Mason <mason@myri.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2011-08-01 11:49:16 -07:00