From: Tiejun Chen <tiejun.c...@windriver.com>

book3e has no real MMU mode so we have to create an identity TLB
mapping to make sure we can access the real physical address.

Signed-off-by: Tiejun Chen <tiejun.c...@windriver.com>
[scottwood: cleanup, and split off some changes]
Signed-off-by: Scott Wood <scottw...@freescale.com>
---
 arch/powerpc/kernel/misc_64.S | 52 ++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 51 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/misc_64.S b/arch/powerpc/kernel/misc_64.S
index 6e4168c..246ad8c 100644
--- a/arch/powerpc/kernel/misc_64.S
+++ b/arch/powerpc/kernel/misc_64.S
@@ -26,6 +26,7 @@
 #include <asm/thread_info.h>
 #include <asm/kexec.h>
 #include <asm/ptrace.h>
+#include <asm/mmu.h>
 
        .text
 
@@ -496,6 +497,51 @@ kexec_flag:
 
 
 #ifdef CONFIG_KEXEC
+#ifdef CONFIG_PPC_BOOK3E
+/*
+ * BOOK3E has no real MMU mode, so we have to setup the initial TLB
+ * for a core to identity map v:0 to p:0.  This current implementation
+ * assumes that 1G is enough for kexec.
+ */
+kexec_create_tlb:
+       /*
+        * Invalidate all non-IPROT TLB entries to avoid any TLB conflict.
+        * IPROT TLB entries should be >= PAGE_OFFSET and thus not conflict.
+        */
+       PPC_TLBILX_ALL(0,R0)
+       sync
+       isync
+
+       mfspr   r10,SPRN_TLB1CFG
+       andi.   r10,r10,TLBnCFG_N_ENTRY /* Extract # entries */
+       subi    r10,r10,1       /* Last entry: no conflict with kernel text */
+       lis     r9,MAS0_TLBSEL(1)@h
+       rlwimi  r9,r10,16,4,15          /* Setup MAS0 = TLBSEL | ESEL(r9) */
+
+/* Set up a temp identity mapping v:0 to p:0 and return to it. */
+#if defined(CONFIG_SMP) || defined(CONFIG_PPC_E500MC)
+#define M_IF_NEEDED    MAS2_M
+#else
+#define M_IF_NEEDED    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_NEEDED)
+       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)
  *
@@ -525,6 +571,10 @@ _GLOBAL(kexec_smp_wait)
  * don't overwrite r3 here, it is live for kexec_wait above.
  */
 real_mode:     /* assume normal blr return */
+#ifdef CONFIG_PPC_BOOK3E
+       /* Create an identity mapping. */
+       b       kexec_create_tlb
+#else
 1:     li      r9,MSR_RI
        li      r10,MSR_DR|MSR_IR
        mflr    r11             /* return address to SRR0 */
@@ -536,7 +586,7 @@ real_mode:  /* assume normal blr return */
        mtspr   SPRN_SRR1,r10
        mtspr   SPRN_SRR0,r11
        rfid
-
+#endif
 
 /*
  * kexec_sequence(newstack, start, image, control, clear_all())
-- 
2.1.4

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