If there is a struct page for the requested mapping then it's
normal RAM and the mapping is set to "M" bit (coherent, cacheable)
otherwise this is treated as I/O and we set "I + G" (cache inhibited, guarded)
This helps setting proper TLB mapping for direct assigned device
Signed-off-by: Bharat Bhushan <bharat.bhushan@xxxxxxxxxxxxx>
---
v2: some cleanup and added comment
-
arch/powerpc/kvm/e500_mmu_host.c | 23 ++++++++++++++++++-----
1 files changed, 18 insertions(+), 5 deletions(-)
diff --git a/arch/powerpc/kvm/e500_mmu_host.c b/arch/powerpc/kvm/e500_mmu_host.c
index 1c6a9d7..02eb973 100644
--- a/arch/powerpc/kvm/e500_mmu_host.c
+++ b/arch/powerpc/kvm/e500_mmu_host.c
@@ -64,13 +64,26 @@ static inline u32 e500_shadow_mas3_attrib(u32 mas3, int usermode)
return mas3;
}
-static inline u32 e500_shadow_mas2_attrib(u32 mas2, int usermode)
+static inline u32 e500_shadow_mas2_attrib(u32 mas2, pfn_t pfn)
{
+ u32 mas2_attr;
+
+ mas2_attr = mas2 & MAS2_ATTRIB_MASK;
+
+ /*
+ * RAM is always mappable on e500 systems, so this is identical
+ * to kvm_is_mmio_pfn(), just without its overhead.
+ */
+ if (!pfn_valid(pfn)) {
+ /* Pages not managed by Kernel are treated as I/O, set I + G */
+ mas2_attr |= MAS2_I | MAS2_G;
#ifdef CONFIG_SMP
- return (mas2 & MAS2_ATTRIB_MASK) | MAS2_M;
-#else
- return mas2 & MAS2_ATTRIB_MASK;
+ } else {
+ /* Kernel managed pages are actually RAM so set "M" */
+ mas2_attr |= MAS2_M;
#endif
+ }
+ return mas2_attr;
}
/*
@@ -313,7 +326,7 @@ static void kvmppc_e500_setup_stlbe(
/* Force IPROT=0 for all guest mappings. */
stlbe->mas1 = MAS1_TSIZE(tsize) | get_tlb_sts(gtlbe) | MAS1_VALID;
stlbe->mas2 = (gvaddr & MAS2_EPN) |
- e500_shadow_mas2_attrib(gtlbe->mas2, pr);
+ e500_shadow_mas2_attrib(gtlbe->mas2, pfn);
stlbe->mas7_3 = ((u64)pfn << PAGE_SHIFT) |
e500_shadow_mas3_attrib(gtlbe->mas7_3, pr);
--
1.7.0.4
--
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