[RFC PATCH 10/11] x86, xen: Cleanup PWT/PCD bit manipulation in Xen
From: Toshi Kani <hidden>
Date: 2014-07-15 19:45:45
Also in:
lkml
Subsystem:
the rest, x86 architecture (32-bit and 64-bit), xen hypervisor x86 · Maintainers:
Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen, Juergen Gross
This patch cleans up the PWT & PCD bit manipulation for the kernel memory types in Xen, and uses _PAGE_CACHE_<type> macros, instead. This keeps the Xen code independent from the PAT slot assignment. Signed-off-by: Toshi Kani <redacted> --- arch/x86/xen/enlighten.c | 2 +- arch/x86/xen/mmu.c | 8 ++++---- 2 files changed, 5 insertions(+), 5 deletions(-)
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index ffb101e..1917bef 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c@@ -1557,7 +1557,7 @@ asmlinkage __visible void __init xen_start_kernel(void) #if 0 if (!xen_initial_domain()) #endif - __supported_pte_mask &= ~(_PAGE_PWT | _PAGE_PCD); + __supported_pte_mask &= ~_PAGE_CACHE_MASK; __supported_pte_mask |= _PAGE_IOMAP;
diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index e8a1201..8ef154a 100644
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c@@ -438,7 +438,7 @@ __visible pteval_t xen_pte_val(pte_t pte) /* If this is a WC pte, convert back from Xen WC to Linux WC */ if ((pteval & (_PAGE_PAT | _PAGE_PCD | _PAGE_PWT)) == _PAGE_PAT) { WARN_ON(!pat_enabled); - pteval = (pteval & ~_PAGE_PAT) | _PAGE_PWT; + pteval = (pteval & ~_PAGE_PAT) | _PAGE_CACHE_WC; } #endif if (xen_initial_domain() && (pteval & _PAGE_IOMAP))
@@ -465,11 +465,11 @@ PV_CALLEE_SAVE_REGS_THUNK(xen_pgd_val); * 0 WB WB WB * 1 PWT WC WT WT * 2 PCD UC- UC- UC- - * 3 PCD PWT UC UC UC + * 3 PCD PWT WT UC UC * 4 PAT WB WC WB * 5 PAT PWT WC WP WT * 6 PAT PCD UC- rsv UC- - * 7 PAT PCD PWT UC rsv UC + * 7 PAT PCD PWT WT rsv UC */ void xen_set_pat(u64 pat)
@@ -492,7 +492,7 @@ __visible pte_t xen_make_pte(pteval_t pte) * but we could see hugetlbfs mappings, I think.). */ if (pat_enabled && !WARN_ON(pte & _PAGE_PAT)) { - if ((pte & (_PAGE_PCD | _PAGE_PWT)) == _PAGE_PWT) + if ((pte & _PAGE_CACHE_MASK) == _PAGE_CACHE_WC) pte = (pte & ~(_PAGE_PCD | _PAGE_PWT)) | _PAGE_PAT; } #endif --
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