diff options
| author | cinap_lenrek <cinap_lenrek@felloff.net> | 2020-05-22 23:58:24 +0200 |
|---|---|---|
| committer | cinap_lenrek <cinap_lenrek@felloff.net> | 2020-05-22 23:58:24 +0200 |
| commit | b86bb35c7d82f097e6572d400527046245b877fd (patch) | |
| tree | 81d8366c8eaf5cfb7df253d3506ffc88c456bb7f /sys/src/9/pc/mmu.c | |
| parent | 0002fd0cf786d16c9b3e1ab62f0cb92b2461f185 (diff) | |
pc, pc64: do page attribute table (PAT) init early in cpuidentify()
the page attribute table was initialized in mmuinit(), which is
too late for bootscreen(). So now we check for PAT support and
insert the write-combine entry early in cpuidentify().
this might have been the cause of some slow EFI framebuffers on
machines with overlapping or insufficient MTRR entries.
Diffstat (limited to 'sys/src/9/pc/mmu.c')
| -rw-r--r-- | sys/src/9/pc/mmu.c | 13 |
1 files changed, 0 insertions, 13 deletions
diff --git a/sys/src/9/pc/mmu.c b/sys/src/9/pc/mmu.c index c0b13674a..614339295 100644 --- a/sys/src/9/pc/mmu.c +++ b/sys/src/9/pc/mmu.c @@ -66,11 +66,6 @@ static void memglobal(void); #define VPTX(va) (((ulong)(va))>>12) #define vpd (vpt+VPTX(VPT)) -enum { - /* PAT entry used for write combining */ - PATWC = 7, -}; - void mmuinit(void) { @@ -125,14 +120,6 @@ mmuinit(void) taskswitch(PADDR(m->pdb), (ulong)m + BY2PG); ltr(TSSSEL); - - /* IA32_PAT write combining */ - if((MACHP(0)->cpuiddx & Pat) != 0 - && rdmsr(0x277, &v) != -1){ - v &= ~(255LL<<(PATWC*8)); - v |= 1LL<<(PATWC*8); /* WC */ - wrmsr(0x277, v); - } } /* |