[v2][PATCH 3/7] book3e/kexec/kdump: create a 1:1 TLB mapping

Tiejun Chen
2013-06-20T07:53:15Z

book3e have no real MMU mode so we have to create a 1:1 TLB
mapping to make sure we can access the real physical address.
And correct something to support this pseudo real mode on book3e.

Signed-off-by: Tiejun Chen <tiejun.chen@windriver.com>
---
arch/powerpc/kernel/head_64.S | 9 ++++---
arch/powerpc/kernel/misc_64.S | 55 ++++++++++++++++++++++++++++++++++++++++-
2 files changed, 60 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S
index 0942f3a..3e19ba2 100644
--- a/arch/powerpc/kernel/head_64.S
+++ b/arch/powerpc/kernel/head_64.S
@@ -444,12 +444,12 @@ _STATIC(__after_prom_start)
tovirt(r3,r3) /* on booke, we already run at PAGE_OFFSET */
#endif
mr. r4,r26 /* In some cases the loader may */
+#if defined(CONFIG_PPC_BOOK3E)
+ tovirt(r4,r4)
+#endif
beq 9f /* have already put us at zero */
li r6,0x100 /* Start offset, the first 0x100 */
/* bytes were copied earlier. */
-#ifdef CONFIG_PPC_BOOK3E
- tovirt(r6,r6) /* on booke, we already run at PAGE_OFFSET */
-#endif

#ifdef CONFIG_RELOCATABLE
/*
@@ -492,6 +492,9 @@ _STATIC(__after_prom_start)
p_end: .llong _end - _stext

4: /* Now copy the rest of the kernel up to _end */
+#if defined(CONFIG_PPC_BOOK3E)
+ tovirt(r26,r26)
+#endif
addis r5,r26,(p_end - _stext)@ha
ld r5,(p_end - _stext)@l(r5) /* get _end */
5: bl .copy_and_flush /* copy the rest */
diff --git a/arch/powerpc/kernel/misc_64.S b/arch/powerpc/kernel/misc_64.S
index f1a7ce7..20cbb98 100644
--- a/arch/powerpc/kernel/misc_64.S
+++ b/arch/powerpc/kernel/misc_64.S
@@ -460,6 +460,49 @@ kexec_flag:

#ifdef CONFIG_KEXEC
+#ifdef CONFIG_PPC_BOOK3E
+/* BOOK3E have no a real MMU mode so we have to setup the initial TLB
+ * for a core to map v:0 to p:0 as 1:1. This current implementation
+ * assume that 1G is enough for kexec.
+ */
+#include <asm/mmu.h>
+kexec_create_tlb:
+ /* Invalidate all TLBs to avoid any TLB conflict. */
+ PPC_TLBILX_ALL(0,R0)
+ sync
+ isync
+
+ mfspr r10,SPRN_TLB1CFG
+ andi. r10,r10,TLBnCFG_N_ENTRY /* Extract # entries */
+ subi r10,r10,1 /* Often its always safe to use last */
+ lis r9,MAS0_TLBSEL(1)@h
+ rlwimi r9,r10,16,4,15 /* Setup MAS0 = TLBSEL | ESEL(r9) */
+
+/* Setup a temp mapping v:0 to p:0 as 1:1 and return to it.
+ */
+#ifdef CONFIG_SMP
+#define M_IF_SMP MAS2_M
+#else
+#define M_IF_SMP 0
+#endif
+ mtspr SPRN_MAS0,r9
+
+ lis r9,(MAS1_VALID|MAS1_IPROT)@h
+ ori r9,r9,(MAS1_TSIZE(BOOK3E_PAGESZ_1GB))@l
+ mtspr SPRN_MAS1,r9
+
+ LOAD_REG_IMMEDIATE(r9, 0x0 | M_IF_SMP)
+ mtspr SPRN_MAS2,r9
+
+ LOAD_REG_IMMEDIATE(r9, 0x0 | MAS3_SR | MAS3_SW | MAS3_SX)
+ mtspr SPRN_MAS3,r9
+ li r9,0
+ mtspr SPRN_MAS7,r9
+
+ tlbwe
+ isync
+ blr
+#endif

/* kexec_smp_wait(void)
*
@@ -473,6 +516,10 @@ kexec_flag:
*/
_GLOBAL(kexec_smp_wait)
lhz r3,PACAHWCPUID(r13)
+#ifdef CONFIG_PPC_BOOK3E
+ /* Create a 1:1 mapping. */
+ bl kexec_create_tlb
+#endif
bl real_mode

li r4,KEXEC_STATE_REAL_MODE
@@ -489,6 +536,7 @@ _GLOBAL(kexec_smp_wait)
* don't overwrite r3 here, it is live for kexec_wait above.
*/
real_mode: /* assume normal blr return */
+#ifndef CONFIG_PPC_BOOK3E
1: li r9,MSR_RI
li r10,MSR_DR|MSR_IR
mflr r11 /* return address to SRR0 */
@@ -500,7 +548,10 @@ real_mode: /* assume normal blr return */
mtspr SPRN_SRR1,r10
mtspr SPRN_SRR0,r11
rfid
-
+#else
+ /* the real mode is nothing for book3e. */
+ blr
+#endif

/*
* kexec_sequence(newstack, start, image, control, clear_all())
@@ -549,6 +600,8 @@ _GLOBAL(kexec_sequence)
mtmsrd r3,1
#else
wrteei 0
+ /* Create a 1:1 mapping. */
+ bl kexec_create_tlb
#endif

/* copy dest pages, flush whole dest image */
--
1.7.9.5