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https://github.com/AuxXxilium/linux_dsm_epyc7002.git
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1b4574292e
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> |
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| boot | ||
| configs | ||
| crypto | ||
| ia32 | ||
| include | ||
| kernel | ||
| kvm | ||
| lguest | ||
| lib | ||
| math-emu | ||
| mm | ||
| net | ||
| oprofile | ||
| pci | ||
| platform | ||
| power | ||
| purgatory | ||
| realmode | ||
| syscalls | ||
| tools | ||
| um | ||
| vdso | ||
| video | ||
| xen | ||
| .gitignore | ||
| Kbuild | ||
| Kconfig | ||
| Kconfig.cpu | ||
| Kconfig.debug | ||
| Makefile | ||
| Makefile_32.cpu | ||
| Makefile.um | ||