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-rw-r--r--arch/powerpc/kernel/head_64.S34
1 files changed, 31 insertions, 3 deletions
diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S
index 116f0868695b..0886ae6dd5be 100644
--- a/arch/powerpc/kernel/head_64.S
+++ b/arch/powerpc/kernel/head_64.S
@@ -122,6 +122,8 @@ __secondary_hold:
#endif
/* Grab our physical cpu number */
mr r24,r3
+ /* stash r4 for book3e */
+ mr r25,r4
/* Tell the master cpu we're here */
/* Relocation is off & we are located at an address less */
@@ -129,16 +131,31 @@ __secondary_hold:
std r24,__secondary_hold_acknowledge-_stext(0)
sync
+ li r26,0
+#ifdef CONFIG_PPC_BOOK3E
+ tovirt(r26,r26)
+#endif
/* All secondary cpus wait here until told to start. */
-100: ld r4,__secondary_hold_spinloop-_stext(0)
+100: ld r4,__secondary_hold_spinloop-_stext(r26)
cmpdi 0,r4,0
beq 100b
#if defined(CONFIG_SMP) || defined(CONFIG_KEXEC)
+#ifdef CONFIG_PPC_BOOK3E
+ tovirt(r4,r4)
+#endif
ld r4,0(r4) /* deref function descriptor */
mtctr r4
mr r3,r24
+ /*
+ * it may be the case that other platforms have r4 right to
+ * begin with, this gives us some safety in case it is not
+ */
+#ifdef CONFIG_PPC_BOOK3E
+ mr r4,r25
+#else
li r4,0
+#endif
/* Make sure that patched code is visible */
isync
bctr
@@ -169,6 +186,7 @@ _GLOBAL(generic_secondary_thread_init)
/* get a valid TOC pointer, wherever we're mapped at */
bl .relative_toc
+ tovirt(r2,r2)
#ifdef CONFIG_PPC_BOOK3E
/* Book3E initialization */
@@ -195,6 +213,7 @@ _GLOBAL(generic_secondary_smp_init)
/* get a valid TOC pointer, wherever we're mapped at */
bl .relative_toc
+ tovirt(r2,r2)
#ifdef CONFIG_PPC_BOOK3E
/* Book3E initialization */
@@ -531,6 +550,7 @@ _GLOBAL(pmac_secondary_start)
/* get TOC pointer (real address) */
bl .relative_toc
+ tovirt(r2,r2)
/* Copy some CPU settings from CPU 0 */
bl .__restore_cpu_ppc970
@@ -665,6 +685,13 @@ _GLOBAL(enable_64b_mode)
* This puts the TOC pointer into r2, offset by 0x8000 (as expected
* by the toolchain). It computes the correct value for wherever we
* are running at the moment, using position-independent code.
+ *
+ * Note: The compiler constructs pointers using offsets from the
+ * TOC in -mcmodel=medium mode. After we relocate to 0 but before
+ * the MMU is on we need our TOC to be a virtual address otherwise
+ * these pointers will be real addresses which may get stored and
+ * accessed later with the MMU on. We use tovirt() at the call
+ * sites to handle this.
*/
_GLOBAL(relative_toc)
mflr r0
@@ -681,8 +708,9 @@ p_toc: .llong __toc_start + 0x8000 - 0b
* This is where the main kernel code starts.
*/
_INIT_STATIC(start_here_multiplatform)
- /* set up the TOC (real address) */
- bl .relative_toc
+ /* set up the TOC */
+ bl .relative_toc
+ tovirt(r2,r2)
/* Clear out the BSS. It may have been done in prom_init,
* already but that's irrelevant since prom_init will soon