linux/arch/x86/pci
Luis R. Rodriguez cb32edf65b x86/mm/pat: Wrap pat_enabled into a function API
We use pat_enabled in x86-specific code to see if PAT is enabled
or not but we're granting full access to it even though readers
do not need to set it. If, for instance, we granted access to it
to modules later they then could override the variable
setting... no bueno.

This renames pat_enabled to a new static variable __pat_enabled.
Folks are redirected to use pat_enabled() now.

Code that sets this can only be internal to pat.c. Apart from
the early kernel parameter "nopat" to disable PAT, we also have
a few cases that disable it later and make use of a helper
pat_disable(). It is wrapped under an ifdef but since that code
cannot run unless PAT was enabled its not required to wrap it
with ifdefs, unwrap that. Likewise, since "nopat" doesn't really
change non-PAT systems just remove that ifdef as well.

Although we could add and use an early_param_off(), these
helpers don't use __read_mostly but we want to keep
__read_mostly for __pat_enabled as this is a hot path -- upon
boot, for instance, a simple guest may see ~4k accesses to
pat_enabled(). Since __read_mostly early boot params are not
that common we don't add a helper for them just yet.

Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Walls <awalls@md.metrocast.net>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Doug Ledford <dledford@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Kyle McMartin <kyle@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1430425520-22275-3-git-send-email-mcgrof@do-not-panic.com
Link: http://lkml.kernel.org/r/1432628901-18044-13-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-27 14:41:01 +02:00
..
acpi.c x86/PCI/ACPI: Make all resources except [io 0xcf8-0xcff] available on PCI bus 2015-04-30 22:17:34 +02:00
amd_bus.c x86/PCI: Clean up and mark early_root_info_init() as deprecated 2014-05-27 10:47:49 -06:00
broadcom_bus.c x86/PCI: Fix Broadcom CNB20LE unintended sign extension 2014-04-25 11:01:08 -06:00
bus_numa.c PCI: Use common resource list management code instead of private implementation 2015-02-05 15:09:25 +01:00
bus_numa.h x86/PCI: put busn resource in pci_root_info for native host bridge drivers 2012-06-13 15:42:24 -06:00
ce4100.c x86/ce4100: Fix PCI configuration register access for devices without interrupts 2012-10-30 10:16:47 +01:00
common.c PCI changes for the v4.1 merge window: 2015-04-13 15:45:47 -07:00
direct.c x86: constify PCI raw ops structures 2011-10-14 09:05:28 -07:00
early.c x86/PCI: remove early PCI pr_debug statements 2009-11-24 15:25:19 -08:00
fixup.c vgaarb: Don't default exclusively to first video device with mem+io 2014-09-16 13:06:18 -06:00
i386.c x86/mm/pat: Wrap pat_enabled into a function API 2015-05-27 14:41:01 +02:00
init.c x86, olpc: Use pci subarch init for OLPC 2010-02-25 19:26:23 -08:00
intel_mid_pci.c Revert "x86/PCI: Refine the way to release PCI IRQ resources" 2015-03-20 14:56:19 +01:00
irq.c Revert "x86/PCI: Refine the way to release PCI IRQ resources" 2015-03-20 14:56:19 +01:00
legacy.c x86/PCI: Use pcibios_scan_root() instead of pci_scan_bus_on_node() 2014-02-03 10:38:18 -07:00
Makefile x86, platforms: Remove NUMAQ 2014-02-27 08:07:39 -08:00
mmconfig_32.c ACPI: Clean up inclusions of ACPI header files 2013-12-07 01:03:14 +01:00
mmconfig_64.c X86: drivers: remove __dev* attributes. 2013-01-03 15:57:04 -08:00
mmconfig-shared.c ACPI and power management updates for v3.20-rc1 2015-02-10 15:09:41 -08:00
numachip.c x86: numachip: APIC driver cleanups 2014-11-04 18:17:27 +01:00
olpc.c x86: constify PCI raw ops structures 2011-10-14 09:05:28 -07:00
pcbios.c x86/PCI: Mark PCI BIOS initialization code as such 2014-09-24 06:46:27 -06:00
sta2x11-fixup.c x86: enable DMA CMA with swiotlb 2014-06-04 16:53:57 -07:00
xen.c PCI changes for the v3.20 merge window: 2015-02-10 14:31:28 -08:00