Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
diff --git a/arch/sparc64/lib/clear_page.S b/arch/sparc64/lib/clear_page.S
new file mode 100644
index 0000000..b59884e
--- /dev/null
+++ b/arch/sparc64/lib/clear_page.S
@@ -0,0 +1,105 @@
+/* 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>
+
+ /* 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.
+ */
+
+#define TTE_BITS_TOP (_PAGE_VALID | _PAGE_SZBITS)
+#define TTE_BITS_BOTTOM (_PAGE_CP | _PAGE_CV | _PAGE_P | _PAGE_L | _PAGE_W)
+
+ .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 %uhi(TTE_BITS_TOP), %g3
+
+ sllx %g3, 32, %g3
+ sub %o0, %g2, %g1 ! paddr
+
+ or %g3, TTE_BITS_BOTTOM, %g3
+ 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
+ flush %g6
+ 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
+