On Thu, May 9, 2013 at 3:46 PM, Andy Lutomirski <l...@amacapital.net> wrote:
> A fair number of drivers (mostly graphics) add write-combining MTRRs.
> Most ignore errors and most add the MTRR even on PAT systems which don't
> need to use MTRRs.
This comment is wrong, as i said we need MTRR on PAT system for VRAM.
Cheers,
Jerome
> This series adds new functions arch_phys_wc_{add,del} that, on PAT-less
> x86 systems with MTRRs, add MTRRs and report errors, and that do nothing
> otherwise. (Other architectures, if any, with a similar mechanism could
> implement them.)
>
> I've only tested the radeon driver, since I don't have test hardware
> easily available for the other drivers.
>
> Benefits include:
> - Simpler code
> - No more complaints about MTRR conflict warnings on PAT systems
> - Eventual unexporting of the MTRR API?
>
> This series eliminates about half of the mtrr_add calls in drivers/.
>
> Changes from v1:
> - Helpers renamed
> - Lots of bugs fixed
>
> The series is also at:
> https://git.kernel.org/cgit/linux/kernel/git/luto/linux.git/log/?h=mtrr_cleanup/rfc_v2
>
> Andy Lutomirski (8):
> Add arch_phys_wc_{add,del} to manipulate WC MTRRs if needed
> drm (ast,cirrus,mgag200,nouveau,savage,vmwgfx): Remove
> drm_mtrr_{add,del}
> drm: Update drm_addmap and drm_mmap to use PAT WC instead of MTRRs
> drm,agpgart: Use pgprot_writecombine for AGP maps and make the MTRR
> optional
> i915: Use arch_phys_wc_{add,del}
> radeon: Switch to arch_phys_wc_add and add a missing ..._del
> uvesafb: Clean up MTRR code
> drm: Remove mtrr_add and mtrr_del fallback hack for non-MTRR systems
>
> Documentation/fb/uvesafb.txt | 16 +++-----
> arch/x86/include/asm/io.h | 7 ++++
> arch/x86/include/asm/mtrr.h | 5 ++-
> arch/x86/kernel/cpu/mtrr/main.c | 48 +++++++++++++++++++++++
> drivers/char/agp/frontend.c | 8 ++--
> drivers/gpu/drm/ast/ast_ttm.c | 13 ++-----
> drivers/gpu/drm/cirrus/cirrus_ttm.c | 15 ++------
> drivers/gpu/drm/drm_bufs.c | 17 +++++----
> drivers/gpu/drm/drm_pci.c | 8 ++--
> drivers/gpu/drm/drm_stub.c | 10 +----
> drivers/gpu/drm/drm_vm.c | 22 +++++------
> drivers/gpu/drm/i915/i915_dma.c | 44 +++------------------
> drivers/gpu/drm/mgag200/mgag200_ttm.c | 14 ++-----
> drivers/gpu/drm/nouveau/nouveau_ttm.c | 13 ++-----
> drivers/gpu/drm/radeon/radeon_object.c | 5 ++-
> drivers/gpu/drm/savage/savage_bci.c | 43 ++++++++-------------
> drivers/gpu/drm/savage/savage_drv.h | 5 +--
> drivers/gpu/drm/vmwgfx/vmwgfx_drv.c | 10 ++---
> drivers/video/uvesafb.c | 70
> +++++++++-------------------------
> include/drm/drmP.h | 34 +----------------
> include/drm/drm_os_linux.h | 16 --------
> include/linux/io.h | 25 ++++++++++++
> include/video/uvesafb.h | 1 +
> 23 files changed, 181 insertions(+), 268 deletions(-)
>
> --
> 1.8.1.4
>
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