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/ppc64/kernel/vdso32/gettimeofday.S b/arch/ppc64/kernel/vdso32/gettimeofday.S
new file mode 100644
index 0000000..ca7f415
--- /dev/null
+++ b/arch/ppc64/kernel/vdso32/gettimeofday.S
@@ -0,0 +1,139 @@
+/*
+ * Userland implementation of gettimeofday() for 32 bits processes in a
+ * ppc64 kernel for use in the vDSO
+ *
+ * Copyright (C) 2004 Benjamin Herrenschmuidt (benh@kernel.crashing.org), IBM Corp.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+#include <linux/config.h>
+#include <asm/processor.h>
+#include <asm/ppc_asm.h>
+#include <asm/vdso.h>
+#include <asm/offsets.h>
+#include <asm/unistd.h>
+
+ .text
+/*
+ * Exact prototype of gettimeofday
+ *
+ * int __kernel_gettimeofday(struct timeval *tv, struct timezone *tz);
+ *
+ */
+V_FUNCTION_BEGIN(__kernel_gettimeofday)
+ .cfi_startproc
+ mflr r12
+ .cfi_register lr,r12
+
+ mr r10,r3 /* r10 saves tv */
+ mr r11,r4 /* r11 saves tz */
+ bl __get_datapage@local /* get data page */
+ mr r9, r3 /* datapage ptr in r9 */
+ bl __do_get_xsec@local /* get xsec from tb & kernel */
+ bne- 2f /* out of line -> do syscall */
+
+ /* seconds are xsec >> 20 */
+ rlwinm r5,r4,12,20,31
+ rlwimi r5,r3,12,0,19
+ stw r5,TVAL32_TV_SEC(r10)
+
+ /* get remaining xsec and convert to usec. we scale
+ * up remaining xsec by 12 bits and get the top 32 bits
+ * of the multiplication
+ */
+ rlwinm r5,r4,12,0,19
+ lis r6,1000000@h
+ ori r6,r6,1000000@l
+ mulhwu r5,r5,r6
+ stw r5,TVAL32_TV_USEC(r10)
+
+ cmpli cr0,r11,0 /* check if tz is NULL */
+ beq 1f
+ lwz r4,CFG_TZ_MINUTEWEST(r9)/* fill tz */
+ lwz r5,CFG_TZ_DSTTIME(r9)
+ stw r4,TZONE_TZ_MINWEST(r11)
+ stw r5,TZONE_TZ_DSTTIME(r11)
+
+1: mtlr r12
+ blr
+
+2: mr r3,r10
+ mr r4,r11
+ li r0,__NR_gettimeofday
+ sc
+ b 1b
+ .cfi_endproc
+V_FUNCTION_END(__kernel_gettimeofday)
+
+/*
+ * This is the core of gettimeofday(), it returns the xsec
+ * value in r3 & r4 and expects the datapage ptr (non clobbered)
+ * in r9. clobbers r0,r4,r5,r6,r7,r8
+*/
+__do_get_xsec:
+ .cfi_startproc
+ /* Check for update count & load values. We use the low
+ * order 32 bits of the update count
+ */
+1: lwz r8,(CFG_TB_UPDATE_COUNT+4)(r9)
+ andi. r0,r8,1 /* pending update ? loop */
+ bne- 1b
+ xor r0,r8,r8 /* create dependency */
+ add r9,r9,r0
+
+ /* Load orig stamp (offset to TB) */
+ lwz r5,CFG_TB_ORIG_STAMP(r9)
+ lwz r6,(CFG_TB_ORIG_STAMP+4)(r9)
+
+ /* Get a stable TB value */
+2: mftbu r3
+ mftbl r4
+ mftbu r0
+ cmpl cr0,r3,r0
+ bne- 2b
+
+ /* Substract tb orig stamp. If the high part is non-zero, we jump to the
+ * slow path which call the syscall. If it's ok, then we have our 32 bits
+ * tb_ticks value in r7
+ */
+ subfc r7,r6,r4
+ subfe. r0,r5,r3
+ bne- 3f
+
+ /* Load scale factor & do multiplication */
+ lwz r5,CFG_TB_TO_XS(r9) /* load values */
+ lwz r6,(CFG_TB_TO_XS+4)(r9)
+ mulhwu r4,r7,r5
+ mulhwu r6,r7,r6
+ mullw r6,r7,r5
+ addc r6,r6,r0
+
+ /* At this point, we have the scaled xsec value in r4 + XER:CA
+ * we load & add the stamp since epoch
+ */
+ lwz r5,CFG_STAMP_XSEC(r9)
+ lwz r6,(CFG_STAMP_XSEC+4)(r9)
+ adde r4,r4,r6
+ addze r3,r5
+
+ /* We now have our result in r3,r4. We create a fake dependency
+ * on that result and re-check the counter
+ */
+ xor r0,r4,r4
+ add r9,r9,r0
+ lwz r0,(CFG_TB_UPDATE_COUNT+4)(r9)
+ cmpl cr0,r8,r0 /* check if updated */
+ bne- 1b
+
+ /* Warning ! The caller expects CR:EQ to be set to indicate a
+ * successful calculation (so it won't fallback to the syscall
+ * method). We have overriden that CR bit in the counter check,
+ * but fortunately, the loop exit condition _is_ CR:EQ set, so
+ * we can exit safely here. If you change this code, be careful
+ * of that side effect.
+ */
+3: blr
+ .cfi_endproc