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authorDavid S. Miller <davem@davemloft.net>2012-09-07 03:13:58 +0200
committerDavid S. Miller <davem@davemloft.net>2012-09-07 03:13:58 +0200
commit4f93d21d2563353df813ee049f6489f340389aab (patch)
treed12bf9282a121c9a326bce958bdc9736b005f5cc /arch/sparc/kernel/ktlb.S
parentsparc64: Fix bugs in unrolled 256-bit loops. (diff)
downloadlinux-4f93d21d2563353df813ee049f6489f340389aab.tar.xz
linux-4f93d21d2563353df813ee049f6489f340389aab.zip
sparc64: Support 2GB and 16GB page sizes for kernel linear mappings.
SPARC-T4 supports 2GB pages. So convert kpte_linear_bitmap into an array of 2-bit values which index into kern_linear_pte_xor. Now kern_linear_pte_xor is used for 4 page size aligned regions, 4MB, 256MB, 2GB, and 16GB respectively. Enabling 2GB pages is currently hardcoded using a check against sun4v_chip_type. In the future this will be done more cleanly by interrogating the machine description which is the correct way to determine this kind of thing. Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'arch/sparc/kernel/ktlb.S')
-rw-r--r--arch/sparc/kernel/ktlb.S25
1 files changed, 10 insertions, 15 deletions
diff --git a/arch/sparc/kernel/ktlb.S b/arch/sparc/kernel/ktlb.S
index 79f310364849..0746e5e32b37 100644
--- a/arch/sparc/kernel/ktlb.S
+++ b/arch/sparc/kernel/ktlb.S
@@ -188,31 +188,26 @@ valid_addr_bitmap_patch:
be,pn %xcc, kvmap_dtlb_longpath
2: sethi %hi(kpte_linear_bitmap), %g2
- or %g2, %lo(kpte_linear_bitmap), %g2
/* Get the 256MB physical address index. */
sllx %g4, 21, %g5
- mov 1, %g7
+ or %g2, %lo(kpte_linear_bitmap), %g2
srlx %g5, 21 + 28, %g5
+ and %g5, (32 - 1), %g7
- /* Don't try this at home kids... this depends upon srlx
- * only taking the low 6 bits of the shift count in %g5.
- */
- sllx %g7, %g5, %g7
-
- /* Divide by 64 to get the offset into the bitmask. */
- srlx %g5, 6, %g5
+ /* Divide by 32 to get the offset into the bitmask. */
+ srlx %g5, 5, %g5
+ add %g7, %g7, %g7
sllx %g5, 3, %g5
- /* kern_linear_pte_xor[((mask & bit) ? 1 : 0)] */
+ /* kern_linear_pte_xor[(mask >> shift) & 3)] */
ldx [%g2 + %g5], %g2
- andcc %g2, %g7, %g0
+ srlx %g2, %g7, %g7
sethi %hi(kern_linear_pte_xor), %g5
+ and %g7, 3, %g7
or %g5, %lo(kern_linear_pte_xor), %g5
- bne,a,pt %xcc, 1f
- add %g5, 8, %g5
-
-1: ldx [%g5], %g2
+ sllx %g7, 3, %g7
+ ldx [%g5 + %g7], %g2
.globl kvmap_linear_patch
kvmap_linear_patch: