path: root/arch/sparc/lib
diff options
authorDavid S. Miller <>2013-09-20 21:50:41 -0700
committerDavid S. Miller <>2013-11-12 15:22:34 -0800
commitb2d438348024b75a1ee8b66b85d77f569a5dfed8 (patch)
tree057c725d9d058d326533d0947aedd226adb57540 /arch/sparc/lib
parentf998c9c0d663b013e3aa3ba78908396c8c497218 (diff)
sparc64: Make PAGE_OFFSET variable.
Choose PAGE_OFFSET dynamically based upon cpu type. Original UltraSPARC-I (spitfire) chips only supported a 44-bit virtual address space. Newer chips (T4 and later) support 52-bit virtual addresses and up to 47-bits of physical memory space. Therefore we have to adjust PAGE_SIZE dynamically based upon the capabilities of the chip. Note that this change alone does not allow us to support > 43-bit physical memory, to do that we need to re-arrange our page table support. The current encodings of the pmd_t and pgd_t pointers restricts us to "32 + 11" == 43 bits. This change can waste quite a bit of memory for the various tables. In particular, a future change should work to size and allocate kern_linear_bitmap[] and sparc64_valid_addr_bitmap[] dynamically. This isn't easy as we really cannot take a TLB miss when accessing kern_linear_bitmap[]. We'd have to lock it into the TLB or similar. Signed-off-by: David S. Miller <> Acked-by: Bob Picco <>
Diffstat (limited to 'arch/sparc/lib')
2 files changed, 4 insertions, 4 deletions
diff --git a/arch/sparc/lib/clear_page.S b/arch/sparc/lib/clear_page.S
index 77e531f6c2a7..46272dfc26e8 100644
--- a/arch/sparc/lib/clear_page.S
+++ b/arch/sparc/lib/clear_page.S
@@ -37,10 +37,10 @@ _clear_page: /* %o0=dest */
.globl clear_user_page
clear_user_page: /* %o0=dest, %o1=vaddr */
lduw [%g6 + TI_PRE_COUNT], %o2
- sethi %uhi(PAGE_OFFSET), %g2
+ sethi %hi(PAGE_OFFSET), %g2
sethi %hi(PAGE_SIZE), %o4
- sllx %g2, 32, %g2
+ ldx [%g2 + %lo(PAGE_OFFSET)], %g2
sethi %hi(PAGE_KERNEL_LOCKED), %g3
ldx [%g3 + %lo(PAGE_KERNEL_LOCKED)], %g3
diff --git a/arch/sparc/lib/copy_page.S b/arch/sparc/lib/copy_page.S
index 4d2df328e514..dd16c61f3263 100644
--- a/arch/sparc/lib/copy_page.S
+++ b/arch/sparc/lib/copy_page.S
@@ -46,10 +46,10 @@
.type copy_user_page,#function
copy_user_page: /* %o0=dest, %o1=src, %o2=vaddr */
lduw [%g6 + TI_PRE_COUNT], %o4
- sethi %uhi(PAGE_OFFSET), %g2
+ sethi %hi(PAGE_OFFSET), %g2
sethi %hi(PAGE_SIZE), %o3
- sllx %g2, 32, %g2
+ ldx [%g2 + %lo(PAGE_OFFSET)], %g2
sethi %hi(PAGE_KERNEL_LOCKED), %g3
ldx [%g3 + %lo(PAGE_KERNEL_LOCKED)], %g3