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Commit cf904e30 authored by Tiejun Chen's avatar Tiejun Chen Committed by Scott Wood
Browse files

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: default avatarTiejun Chen <tiejun.chen@windriver.com>
[scottwood: cleanup, and split off some changes]
Signed-off-by: default avatarScott Wood <scottwood@freescale.com>
parent ecc4999f

arch/powerpc/kernel/misc_64.S

+51 −1
Original line number Diff line number Diff line
@@ -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())