linux_dsm_epyc7002/arch
Aravind Gopalakrishnan 1b4574292e x86/gart: Check for GART support before accessing GART registers
GART registers are not present in newer AMD processors (Fam15h, Model
10h and later). So, avoid accessing those in PCI config space by
returning early in early_gart_iommu_check() and gart_iommu_hole_init()
if GART is not available.

Current code doesn't break on existing processors but there are some
side effects:

We get bogus AGP aperture messages which are simply noise on
GART-less processors:

  AGP: Node 0: aperture [bus addr 0x00000000-0x01ffffff] (32MB)
  AGP: Your BIOS doesn't leave aperture memory hole
  AGP: Please enable the IOMMU option in the BIOS setup
  AGP: This costs you 64MB of RAM
  AGP: Mapping aperture over RAM [mem 0xd4000000-0xd7ffffff]

We can avoid calling allocate_aperture() and would not have to
wastefully reserve 64MB of RAM with memblock_reserve(). Also, we can
avoid having to loop through all PCI buses and devices twice, searching
for a non-existent AGP bridge if we bail out early.

Refactor the family check used in amd_nb.c into an inline function so we
can use it here as well as in amd_nb.c

Fix some typos while at it.

Tested the patch on Fam10h and Fam15h Model 00h-fh and this code runs
fine. On Fam15h Model 60h-6fh and on Fam16h, we bail early as they don't
have GART.

Signed-off-by: Aravind Gopalakrishnan <Aravind.Gopalakrishnan@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Joerg Rodel <joro@8bytes.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1428443197-3834-1-git-send-email-Aravind.Gopalakrishnan@amd.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-06 11:15:53 +02:00
..
alpha alpha: forward declare struct pt_regs in processor.h 2015-04-17 09:03:53 -04:00
arc ARC changes for 4.1-rc1: 2015-04-24 07:55:54 -07:00
arm This mostly includes the PPC changes for 4.1, which this time cover 2015-04-26 13:06:22 -07:00
arm64 arm64: perf: Fix the pmu node name in warning message 2015-04-30 12:11:30 +01:00
avr32 Merge branch 'exec_domain_rip_v2' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/misc 2015-04-15 13:53:55 -07:00
blackfin blackfin updates for Linux 4.1 2015-04-24 07:58:07 -07:00
c6x C6X Fixes for v4.1 2015-04-16 18:48:55 -04:00
cris CRIS changes for 4.1 2015-04-26 13:31:05 -07:00
frv Devicetree updates for 4.1: 2015-04-24 08:46:18 -07:00
hexagon Merge branch 'exec_domain_rip_v2' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/misc 2015-04-15 13:53:55 -07:00
ia64 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2015-04-26 17:22:07 -07:00
m32r Char/Misc driver patches for 4.1-rc1 2015-04-21 09:42:58 -07:00
m68k Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gerg/m68knommu 2015-04-20 10:12:29 -07:00
metag Metag architecture changes for v4.1 2015-04-24 07:56:50 -07:00
microblaze microblaze: use asm-generic for seccomp.h 2015-04-17 09:04:10 -04:00
mips TTY/Serial patches for 4.1-rc1 2015-04-21 09:33:10 -07:00
mn10300 Devicetree updates for 4.1: 2015-04-24 08:46:18 -07:00
nios2 nios2 update for v4.1-rc1 2015-04-24 07:59:07 -07:00
openrisc Merge branch 'akpm' (patches from Andrew) 2015-04-15 16:39:15 -07:00
parisc parisc: Replace PT_NLEVELS with CONFIG_PGTABLE_LEVELS 2015-04-21 22:04:03 +02:00
powerpc powerpc/powernv: Restore non-volatile CRs after nap 2015-05-01 16:55:11 +10:00
s390 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux 2015-04-28 09:58:46 -07:00
score arch: Remove exec_domain from remaining archs 2015-04-12 21:03:30 +02:00
sh Merge branch 'for-linus' of git://git.infradead.org/users/vkoul/slave-dma 2015-04-24 09:49:37 -07:00
sparc Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc 2015-04-21 23:21:34 -07:00
tile tile: properly use node_isset() on a nodemask_t 2015-04-28 10:36:45 -04:00
um Merge branch 'exec_domain_rip_v2' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/misc 2015-04-15 13:53:55 -07:00
unicore32 Merge branch 'exec_domain_rip_v2' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/misc 2015-04-15 13:53:55 -07:00
x86 x86/gart: Check for GART support before accessing GART registers 2015-05-06 11:15:53 +02:00
xtensa Xtensa changes and fixes for 4.1 2015-04-17 15:32:30 -04:00
.gitignore
Kconfig powerpc updates for 4.1 2015-04-16 13:53:32 -05:00