Commit 7aa8dd67 authored by Christophe Leroy's avatar Christophe Leroy Committed by Michael Ellerman
Browse files

powerpc/32: Always enable data translation in exception prolog 



If the code can use a stack in vm area, it can also use a
stack in linear space.

Simplify code by removing old non VMAP stack code on PPC32.

That means the data translation is now re-enabled early in
exception prolog in all cases, not only when using VMAP stacks.

While we are touching EXCEPTION_PROLOG macros, remove the
unused for_rtas parameter in EXCEPTION_PROLOG_1.

Signed-off-by: default avatarChristophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/7cd6440c60a7e8f4f035b245c57720f51e225aae.1615552866.git.christophe.leroy@csgroup.eu
parent 57472306

arch/powerpc/include/asm/processor.h

+1 −3
Original line number Diff line number Diff line
@@ -147,11 +147,9 @@ struct thread_struct { 
#ifdef CONFIG_PPC_RTAS

	unsigned long	rtas_sp;	/* stack pointer for when in RTAS */

#endif

#endif

#if defined(CONFIG_PPC_BOOK3S_32) && defined(CONFIG_PPC_KUAP)

	unsigned long	kuap;		/* opened segments for user access */

#endif

#ifdef CONFIG_VMAP_STACK

	unsigned long	srr0;

	unsigned long	srr1;

	unsigned long	dar;
@@ -160,7 +158,7 @@ struct thread_struct { 
	unsigned long	r0, r3, r4, r5, r6, r8, r9, r11;

	unsigned long	lr, ctr;

#endif

#endif

#endif /* CONFIG_PPC32 */

	/* Debug Registers */

	struct debug_reg debug;

#ifdef CONFIG_PPC_FPU_REGS

arch/powerpc/kernel/asm-offsets.c

+0 −2
Original line number Diff line number Diff line
@@ -131,7 +131,6 @@ int main(void) 
	OFFSET(KSP_VSID, thread_struct, ksp_vsid);

#else /* CONFIG_PPC64 */

	OFFSET(PGDIR, thread_struct, pgdir);

#ifdef CONFIG_VMAP_STACK

	OFFSET(SRR0, thread_struct, srr0);

	OFFSET(SRR1, thread_struct, srr1);

	OFFSET(DAR, thread_struct, dar);
@@ -148,7 +147,6 @@ int main(void) 
	OFFSET(THLR, thread_struct, lr);

	OFFSET(THCTR, thread_struct, ctr);

#endif

#endif

#ifdef CONFIG_SPE

	OFFSET(THREAD_EVR0, thread_struct, evr[0]);

	OFFSET(THREAD_ACC, thread_struct, acc);

arch/powerpc/kernel/entry_32.S

+7 −12
Original line number Diff line number Diff line
@@ -129,7 +129,7 @@ transfer_to_handler: 
	stw	r12,_CTR(r11)

	stw	r2,_XER(r11)

	mfspr	r12,SPRN_SPRG_THREAD

	tovirt_vmstack r12, r12

	tovirt(r12, r12)

	beq	2f			/* if from user, fix up THREAD.regs */

	addi	r2, r12, -THREAD

	addi	r11,r1,STACK_FRAME_OVERHEAD
@@ -153,8 +153,7 @@ transfer_to_handler: 
transfer_to_handler_cont:

3:

	mflr	r9

	tovirt_novmstack r2, r2 	/* set r2 to current */

	tovirt_vmstack r9, r9

	tovirt(r9, r9)

	lwz	r11,0(r9)		/* virtual address of handler */

	lwz	r9,4(r9)		/* where to go when done */

#if defined(CONFIG_PPC_8xx) && defined(CONFIG_PERF_EVENTS)
@@ -933,7 +932,6 @@ _GLOBAL(enter_rtas) 
	lis	r6,1f@ha	/* physical return address for rtas */

	addi	r6,r6,1f@l

	tophys(r6,r6)

	tophys_novmstack r7, r1

	lwz	r8,RTASENTRY(r4)

	lwz	r4,RTASBASE(r4)

	mfmsr	r9
@@ -942,22 +940,19 @@ _GLOBAL(enter_rtas) 
	mtmsr	r0	/* disable interrupts so SRR0/1 don't get trashed */

	li	r9,MSR_KERNEL & ~(MSR_IR|MSR_DR)

	mtlr	r6

	stw	r7, THREAD + RTAS_SP(r2)

	stw	r1, THREAD + RTAS_SP(r2)

	mtspr	SPRN_SRR0,r8

	mtspr	SPRN_SRR1,r9

	rfi

1:	tophys_novmstack r9, r1

#ifdef CONFIG_VMAP_STACK

1:

	li	r0, MSR_KERNEL & ~MSR_IR	/* can take DTLB miss */

	mtmsr	r0

	isync

#endif

	lwz	r8,INT_FRAME_SIZE+4(r9)	/* get return address */

	lwz	r9,8(r9)	/* original msr value */

	lwz	r8,INT_FRAME_SIZE+4(r1)	/* get return address */

	lwz	r9,8(r1)	/* original msr value */

	addi	r1,r1,INT_FRAME_SIZE

	li	r0,0

	tophys_novmstack r7, r2

	stw	r0, THREAD + RTAS_SP(r7)

	stw	r0, THREAD + RTAS_SP(r2)

	mtspr	SPRN_SRR0,r8

	mtspr	SPRN_SRR1,r9

	rfi			/* return to caller */

arch/powerpc/kernel/fpu.S

+0 −2
Original line number Diff line number Diff line
@@ -92,9 +92,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_VSX) 
	/* enable use of FP after return */

#ifdef CONFIG_PPC32

	mfspr	r5,SPRN_SPRG_THREAD	/* current task's THREAD (phys) */

#ifdef CONFIG_VMAP_STACK

	tovirt(r5, r5)

#endif

	lwz	r4,THREAD_FPEXC_MODE(r5)

	ori	r9,r9,MSR_FP		/* enable FP for current */

	or	r9,r9,r4

arch/powerpc/kernel/head_32.h

+2 −83
Original line number Diff line number Diff line
@@ -19,7 +19,6 @@ 
.macro EXCEPTION_PROLOG_0 handle_dar_dsisr=0

	mtspr	SPRN_SPRG_SCRATCH0,r10

	mtspr	SPRN_SPRG_SCRATCH1,r11

#ifdef CONFIG_VMAP_STACK

	mfspr	r10, SPRN_SPRG_THREAD

	.if	\handle_dar_dsisr

#ifdef CONFIG_40x
@@ -37,17 +36,13 @@ 
	.endif

	mfspr	r11, SPRN_SRR0

	stw	r11, SRR0(r10)

#endif

	mfspr	r11, SPRN_SRR1		/* check whether user or kernel */

#ifdef CONFIG_VMAP_STACK

	stw	r11, SRR1(r10)

#endif

	mfcr	r10

	andi.	r11, r11, MSR_PR

.endm



.macro EXCEPTION_PROLOG_1 for_rtas=0

#ifdef CONFIG_VMAP_STACK

.macro EXCEPTION_PROLOG_1

	mtspr	SPRN_SPRG_SCRATCH2,r1

	subi	r1, r1, INT_FRAME_SIZE		/* use r1 if kernel */

	beq	1f
@@ -55,20 +50,13 @@ 
	lwz	r1,TASK_STACK-THREAD(r1)

	addi	r1, r1, THREAD_SIZE - INT_FRAME_SIZE

1:

#ifdef CONFIG_VMAP_STACK

	mtcrf	0x3f, r1

	bt	32 - THREAD_ALIGN_SHIFT, stack_overflow

#else

	subi	r11, r1, INT_FRAME_SIZE		/* use r1 if kernel */

	beq	1f

	mfspr	r11,SPRN_SPRG_THREAD

	lwz	r11,TASK_STACK-THREAD(r11)

	addi	r11, r11, THREAD_SIZE - INT_FRAME_SIZE

1:	tophys(r11, r11)

#endif

.endm



.macro EXCEPTION_PROLOG_2 handle_dar_dsisr=0

#ifdef CONFIG_VMAP_STACK

	LOAD_REG_IMMEDIATE(r11, MSR_KERNEL & ~(MSR_IR | MSR_RI)) /* can take DTLB miss */

	mtmsr	r11

	isync
@@ -76,11 +64,6 @@ 
	stw	r11,GPR1(r1)

	stw	r11,0(r1)

	mr	r11, r1

#else

	stw	r1,GPR1(r11)

	stw	r1,0(r11)

	tovirt(r1, r11)		/* set new kernel sp */

#endif

	stw	r10,_CCR(r11)		/* save registers */

	stw	r12,GPR12(r11)

	stw	r9,GPR9(r11)
@@ -90,7 +73,6 @@ 
	stw	r12,GPR11(r11)

	mflr	r10

	stw	r10,_LINK(r11)

#ifdef CONFIG_VMAP_STACK

	mfspr	r12, SPRN_SPRG_THREAD

	tovirt(r12, r12)

	.if	\handle_dar_dsisr
@@ -101,20 +83,12 @@ 
	.endif

	lwz	r9, SRR1(r12)

	lwz	r12, SRR0(r12)

#else

	mfspr	r12,SPRN_SRR0

	mfspr	r9,SPRN_SRR1

#endif

#ifdef CONFIG_40x

	rlwinm	r9,r9,0,14,12		/* clear MSR_WE (necessary?) */

#elif defined(CONFIG_PPC_8xx)

	mtspr	SPRN_EID, r2		/* Set MSR_RI */

#else

#ifdef CONFIG_VMAP_STACK

	li	r10, MSR_KERNEL & ~MSR_IR /* can take exceptions */

#else

	li	r10,MSR_KERNEL & ~(MSR_IR|MSR_DR) /* can take exceptions */

#endif

	mtmsr	r10			/* (except for mach check in rtas) */

#endif

	stw	r0,GPR0(r11)
@@ -166,59 +140,6 @@ 
	b	transfer_to_syscall		/* jump to handler */

.endm



.macro save_dar_dsisr_on_stack reg1, reg2, sp

#ifndef CONFIG_VMAP_STACK

#ifdef CONFIG_40x

	mfspr	\reg1, SPRN_DEAR

	mfspr	\reg2, SPRN_ESR

#else

	mfspr	\reg1, SPRN_DAR

	mfspr	\reg2, SPRN_DSISR

#endif

	stw	\reg1, _DAR(\sp)

	stw	\reg2, _DSISR(\sp)

#endif

.endm



.macro get_and_save_dar_dsisr_on_stack reg1, reg2, sp

#ifdef CONFIG_VMAP_STACK

	lwz	\reg1, _DAR(\sp)

	lwz	\reg2, _DSISR(\sp)

#else

	save_dar_dsisr_on_stack \reg1, \reg2, \sp

#endif

.endm



.macro tovirt_vmstack dst, src

#ifdef CONFIG_VMAP_STACK

	tovirt(\dst, \src)

#else

	.ifnc	\dst, \src

	mr	\dst, \src

	.endif

#endif

.endm



.macro tovirt_novmstack dst, src

#ifndef CONFIG_VMAP_STACK

	tovirt(\dst, \src)

#else

	.ifnc	\dst, \src

	mr	\dst, \src

	.endif

#endif

.endm



.macro tophys_novmstack dst, src

#ifndef CONFIG_VMAP_STACK

	tophys(\dst, \src)

#else

	.ifnc	\dst, \src

	mr	\dst, \src

	.endif

#endif

.endm



/*

 * Note: code which follows this uses cr0.eq (set if from kernel),

 * r11, r12 (SRR0), and r9 (SRR1).
@@ -266,7 +187,6 @@ 
			  ret_from_except)



.macro vmap_stack_overflow_exception

#ifdef CONFIG_VMAP_STACK

#ifdef CONFIG_SMP

	mfspr	r1, SPRN_SPRG_THREAD

	lwz	r1, TASK_CPU - THREAD(r1)
@@ -285,7 +205,6 @@ 
	SAVE_NVGPRS(r11)

	addi	r3, r1, STACK_FRAME_OVERHEAD

	EXC_XFER_STD(0, stack_overflow_exception)

#endif

.endm



#endif /* __HEAD_32_H__ */