Commit 48cd9b5d authored by Scott Wood's avatar Scott Wood
Browse files

powerpc/e6500: Work around erratum A-008139 



Erratum A-008139 can cause duplicate TLB entries if an indirect
entry is overwritten using tlbwe while the other thread is using it to
do a lookup.  Work around this by using tlbilx to invalidate prior
to overwriting.

To avoid the need to save another register to hold MAS1 during the
workaround code, TID clearing has been moved from tlb_miss_kernel_e6500
until after the SMT section.

Signed-off-by: default avatarScott Wood <scottwood@freescale.com>
parent e16c8765

arch/powerpc/mm/tlb_low_64e.S

+56 −12
Original line number Diff line number Diff line
@@ -299,7 +299,9 @@ itlb_miss_fault_bolted: 
 * r10 = crap (free to use)

 */

tlb_miss_common_e6500:

BEGIN_FTR_SECTION

	crmove	cr2*4+2,cr0*4+2		/* cr2.eq != 0 if kernel address */



BEGIN_FTR_SECTION		/* CPU_FTR_SMT */

	/*

	 * Search if we already have an indirect entry for that virtual

	 * address, and if we do, bail out.
@@ -324,17 +326,62 @@ BEGIN_FTR_SECTION 
	b	1b

	.previous



	/*

	 * Erratum A-008139 says that we can't use tlbwe to change

	 * an indirect entry in any way (including replacing or

	 * invalidating) if the other thread could be in the process

	 * of a lookup.  The workaround is to invalidate the entry

	 * with tlbilx before overwriting.

	 */



	lbz	r15,TCD_ESEL_NEXT(r11)

	rlwinm	r10,r15,16,0xff0000

	oris	r10,r10,MAS0_TLBSEL(1)@h

	mtspr	SPRN_MAS0,r10

	isync

	tlbre

	mfspr	r15,SPRN_MAS1

	mfspr	r10,SPRN_MAS2

	andis.	r15,r15,MAS1_VALID@h

	beq	5f



BEGIN_FTR_SECTION_NESTED(532)

	mfspr	r10,SPRN_MAS8

	rlwinm	r10,r10,0,0x80000fff  /* tgs,tlpid -> sgs,slpid */

	mtspr	SPRN_MAS5,r10

END_FTR_SECTION_NESTED(CPU_FTR_EMB_HV,CPU_FTR_EMB_HV,532)



	tlbsx	0,r16

	mtspr	SPRN_MAS2,r10

	mfspr	r10,SPRN_MAS1

	mtspr	SPRN_MAS1,r15

	rlwinm	r15,r10,0,0x3fff0000  /* tid -> spid */

	rlwimi	r15,r10,20,0x00000003 /* ind,ts -> sind,sas */

	mfspr	r10,SPRN_MAS6

	mtspr	SPRN_MAS6,r15



	mfspr	r15,SPRN_MAS2

	isync

	tlbilxva 0,r15

	isync



	mtspr	SPRN_MAS6,r10



	andis.	r10,r10,MAS1_VALID@h

5:

BEGIN_FTR_SECTION_NESTED(532)

	li	r10,0

	mtspr	SPRN_MAS8,r10

	mtspr	SPRN_MAS5,r10

END_FTR_SECTION_NESTED(CPU_FTR_EMB_HV,CPU_FTR_EMB_HV,532)



	tlbsx	0,r16

	mfspr	r10,SPRN_MAS1

	andis.	r15,r10,MAS1_VALID@h

	bne	tlb_miss_done_e6500

END_FTR_SECTION_IFSET(CPU_FTR_SMT)

FTR_SECTION_ELSE

	mfspr	r10,SPRN_MAS1

ALT_FTR_SECTION_END_IFSET(CPU_FTR_SMT)



	oris	r10,r10,MAS1_VALID@h

	beq	cr2,4f

	rlwinm	r10,r10,0,16,1		/* Clear TID */

4:	mtspr	SPRN_MAS1,r10



	/* Now, we need to walk the page tables. First check if we are in

	 * range.
@@ -410,12 +457,9 @@ END_FTR_SECTION_IFSET(CPU_FTR_SMT) 
	rfi



tlb_miss_kernel_e6500:

	mfspr	r10,SPRN_MAS1

	ld	r14,PACA_KERNELPGD(r13)

	cmpldi	cr0,r15,8		/* Check for vmalloc region */

	rlwinm	r10,r10,0,16,1		/* Clear TID */

	mtspr	SPRN_MAS1,r10

	beq+	tlb_miss_common_e6500

	cmpldi	cr1,r15,8		/* Check for vmalloc region */

	beq+	cr1,tlb_miss_common_e6500



tlb_miss_fault_e6500:

	tlb_unlock_e6500

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