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authorLinus Torvalds <torvalds@linux-foundation.org>2008-12-30 17:23:31 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2008-12-30 17:23:31 -0800
commit6de71484cf9561edb45224f659a9db38b6056d5e (patch)
tree588fe6f7c98147b805085503c863d371e2fa497e /arch/sparc/lib/clear_page.S
parent1dff81f20cd55ffa5a8ee984da70ce0b99d29606 (diff)
parente3c6d4ee545e427b55882d97d3b663c6411645fe (diff)
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-next-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-next-2.6: (98 commits) sparc: move select of ARCH_SUPPORTS_MSI sparc: drop SUN_IO sparc: unify sections.h sparc: use .data.init_task section for init_thread_union sparc: fix array overrun check in of_device_64.c sparc: unify module.c sparc64: prepare module_64.c for unification sparc64: use bit neutral Elf symbols sparc: unify module.h sparc: introduce CONFIG_BITS sparc: fix hardirq.h removal fallout sparc64: do not export pus_fs_struct sparc: use sparc64 version of scatterlist.h sparc: Commonize memcmp assembler. sparc: Unify strlen assembler. sparc: Add asm/asm.h sparc: Kill memcmp_32.S code which has been ifdef'd out for centuries. sparc: replace for_each_cpu_mask_nr with for_each_cpu sparc: fix sparse warnings in irq_32.c sparc: add include guards to kernel.h ...
Diffstat (limited to 'arch/sparc/lib/clear_page.S')
-rw-r--r--arch/sparc/lib/clear_page.S103
1 files changed, 103 insertions, 0 deletions
diff --git a/arch/sparc/lib/clear_page.S b/arch/sparc/lib/clear_page.S
new file mode 100644
index 00000000000..77e531f6c2a
--- /dev/null
+++ b/arch/sparc/lib/clear_page.S
@@ -0,0 +1,103 @@
+/* clear_page.S: UltraSparc optimized clear page.
+ *
+ * Copyright (C) 1996, 1998, 1999, 2000, 2004 David S. Miller (davem@redhat.com)
+ * Copyright (C) 1997 Jakub Jelinek (jakub@redhat.com)
+ */
+
+#include <asm/visasm.h>
+#include <asm/thread_info.h>
+#include <asm/page.h>
+#include <asm/pgtable.h>
+#include <asm/spitfire.h>
+#include <asm/head.h>
+
+ /* What we used to do was lock a TLB entry into a specific
+ * TLB slot, clear the page with interrupts disabled, then
+ * restore the original TLB entry. This was great for
+ * disturbing the TLB as little as possible, but it meant
+ * we had to keep interrupts disabled for a long time.
+ *
+ * Now, we simply use the normal TLB loading mechanism,
+ * and this makes the cpu choose a slot all by itself.
+ * Then we do a normal TLB flush on exit. We need only
+ * disable preemption during the clear.
+ */
+
+ .text
+
+ .globl _clear_page
+_clear_page: /* %o0=dest */
+ ba,pt %xcc, clear_page_common
+ clr %o4
+
+ /* This thing is pretty important, it shows up
+ * on the profiles via do_anonymous_page().
+ */
+ .align 32
+ .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_SIZE), %o4
+
+ sllx %g2, 32, %g2
+ sethi %hi(PAGE_KERNEL_LOCKED), %g3
+
+ ldx [%g3 + %lo(PAGE_KERNEL_LOCKED)], %g3
+ sub %o0, %g2, %g1 ! paddr
+
+ and %o1, %o4, %o0 ! vaddr D-cache alias bit
+
+ or %g1, %g3, %g1 ! TTE data
+ sethi %hi(TLBTEMP_BASE), %o3
+
+ add %o2, 1, %o4
+ add %o0, %o3, %o0 ! TTE vaddr
+
+ /* Disable preemption. */
+ mov TLB_TAG_ACCESS, %g3
+ stw %o4, [%g6 + TI_PRE_COUNT]
+
+ /* Load TLB entry. */
+ rdpr %pstate, %o4
+ wrpr %o4, PSTATE_IE, %pstate
+ stxa %o0, [%g3] ASI_DMMU
+ stxa %g1, [%g0] ASI_DTLB_DATA_IN
+ sethi %hi(KERNBASE), %g1
+ flush %g1
+ wrpr %o4, 0x0, %pstate
+
+ mov 1, %o4
+
+clear_page_common:
+ VISEntryHalf
+ membar #StoreLoad | #StoreStore | #LoadStore
+ fzero %f0
+ sethi %hi(PAGE_SIZE/64), %o1
+ mov %o0, %g1 ! remember vaddr for tlbflush
+ fzero %f2
+ or %o1, %lo(PAGE_SIZE/64), %o1
+ faddd %f0, %f2, %f4
+ fmuld %f0, %f2, %f6
+ faddd %f0, %f2, %f8
+ fmuld %f0, %f2, %f10
+
+ faddd %f0, %f2, %f12
+ fmuld %f0, %f2, %f14
+1: stda %f0, [%o0 + %g0] ASI_BLK_P
+ subcc %o1, 1, %o1
+ bne,pt %icc, 1b
+ add %o0, 0x40, %o0
+ membar #Sync
+ VISExitHalf
+
+ brz,pn %o4, out
+ nop
+
+ stxa %g0, [%g1] ASI_DMMU_DEMAP
+ membar #Sync
+ stw %o2, [%g6 + TI_PRE_COUNT]
+
+out: retl
+ nop
+