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author | Suresh Siddha <suresh.b.siddha@intel.com> | 2008-04-25 17:07:22 -0700 |
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committer | Ingo Molnar <mingo@elte.hu> | 2008-04-30 23:15:35 +0200 |
commit | de33c442ed2a465d2d7804b26dafd2eec067aa34 (patch) | |
tree | 02a9cb2b96d0ad535f0dbfbdccc35afe21aa052e /arch/arm/mach-omap1/io.c | |
parent | b9b39bfba5b0de3418305f01cfa7bc55a16004e1 (diff) |
x86 PAT: fix performance drop for glx, use UC minus for ioremap(), ioremap_nocache() and pci_mmap_page_range()
Use UC_MINUS for ioremap(), ioremap_nocache() instead of strong UC.
Once all the X drivers move to ioremap_wc(), we can go back to strong
UC semantics for ioremap() and ioremap_nocache().
To avoid attribute aliasing issues, pci_mmap_page_range() will also
use UC_MINUS for default non write-combining mapping request.
Next steps:
a) change all the video drivers using ioremap() or ioremap_nocache()
and adding WC MTTR using mttr_add() to ioremap_wc()
b) for strict usage, we can go back to strong uc semantics
for ioremap() and ioremap_nocache() after some grace period for
completing step-a.
c) user level X server needs to use the appropriate method for setting
up WC mapping (like using resourceX_wc sysfs file instead of
adding MTRR for WC and using /dev/mem or resourceX under /sys)
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'arch/arm/mach-omap1/io.c')
0 files changed, 0 insertions, 0 deletions