diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/i386/kernel/cpu/mtrr/state.c |
Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'arch/i386/kernel/cpu/mtrr/state.c')
-rw-r--r-- | arch/i386/kernel/cpu/mtrr/state.c | 78 |
1 files changed, 78 insertions, 0 deletions
diff --git a/arch/i386/kernel/cpu/mtrr/state.c b/arch/i386/kernel/cpu/mtrr/state.c new file mode 100644 index 00000000000..f62ecd15811 --- /dev/null +++ b/arch/i386/kernel/cpu/mtrr/state.c @@ -0,0 +1,78 @@ +#include <linux/mm.h> +#include <linux/init.h> +#include <asm/io.h> +#include <asm/mtrr.h> +#include <asm/msr.h> +#include "mtrr.h" + + +/* Put the processor into a state where MTRRs can be safely set */ +void set_mtrr_prepare_save(struct set_mtrr_context *ctxt) +{ + unsigned int cr0; + + /* Disable interrupts locally */ + local_irq_save(ctxt->flags); + + if (use_intel() || is_cpu(CYRIX)) { + + /* Save value of CR4 and clear Page Global Enable (bit 7) */ + if ( cpu_has_pge ) { + ctxt->cr4val = read_cr4(); + write_cr4(ctxt->cr4val & (unsigned char) ~(1 << 7)); + } + + /* Disable and flush caches. Note that wbinvd flushes the TLBs as + a side-effect */ + cr0 = read_cr0() | 0x40000000; + wbinvd(); + write_cr0(cr0); + wbinvd(); + + if (use_intel()) + /* Save MTRR state */ + rdmsr(MTRRdefType_MSR, ctxt->deftype_lo, ctxt->deftype_hi); + else + /* Cyrix ARRs - everything else were excluded at the top */ + ctxt->ccr3 = getCx86(CX86_CCR3); + } +} + +void set_mtrr_cache_disable(struct set_mtrr_context *ctxt) +{ + if (use_intel()) + /* Disable MTRRs, and set the default type to uncached */ + mtrr_wrmsr(MTRRdefType_MSR, ctxt->deftype_lo & 0xf300UL, + ctxt->deftype_hi); + else if (is_cpu(CYRIX)) + /* Cyrix ARRs - everything else were excluded at the top */ + setCx86(CX86_CCR3, (ctxt->ccr3 & 0x0f) | 0x10); +} + +/* Restore the processor after a set_mtrr_prepare */ +void set_mtrr_done(struct set_mtrr_context *ctxt) +{ + if (use_intel() || is_cpu(CYRIX)) { + + /* Flush caches and TLBs */ + wbinvd(); + + /* Restore MTRRdefType */ + if (use_intel()) + /* Intel (P6) standard MTRRs */ + mtrr_wrmsr(MTRRdefType_MSR, ctxt->deftype_lo, ctxt->deftype_hi); + else + /* Cyrix ARRs - everything else was excluded at the top */ + setCx86(CX86_CCR3, ctxt->ccr3); + + /* Enable caches */ + write_cr0(read_cr0() & 0xbfffffff); + + /* Restore value of CR4 */ + if ( cpu_has_pge ) + write_cr4(ctxt->cr4val); + } + /* Re-enable interrupts locally (if enabled previously) */ + local_irq_restore(ctxt->flags); +} + |