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| author | Tiejun Chen <tiejun.chen@windriver.com> | 2015-10-06 22:48:18 -0500 |
|---|---|---|
| committer | Scott Wood <scottwood@freescale.com> | 2015-10-27 18:13:28 -0500 |
| commit | cf904e3088fd3760d9f6fed5fde755ac299590b7 (patch) | |
| tree | b8c8b88fc9988aace9b9ad0a58230814a785526d /arch/powerpc | |
| parent | ecc4999f68d157a25c500d18586a16f09a029cb4 (diff) | |
| download | lwn-cf904e3088fd3760d9f6fed5fde755ac299590b7.tar.gz lwn-cf904e3088fd3760d9f6fed5fde755ac299590b7.zip | |
powerpc/book3e-64/kexec: create an identity TLB mapping
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.chen@windriver.com>
[scottwood: cleanup, and split off some changes]
Signed-off-by: Scott Wood <scottwood@freescale.com>
Diffstat (limited to 'arch/powerpc')
| -rw-r--r-- | arch/powerpc/kernel/misc_64.S | 52 |
1 files changed, 51 insertions, 1 deletions
diff --git a/arch/powerpc/kernel/misc_64.S b/arch/powerpc/kernel/misc_64.S index 6e4168cf4698..246ad8c525b1 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()) |