Commit dc13b889 authored by Christophe Leroy's avatar Christophe Leroy Committed by Michael Ellerman
Browse files

powerpc/32: Move exception prolog code into .text once MMU is back on 



The space in the head section is rather constrained by the fact that
exception vectors are spread every 0x100 bytes and sometimes we
need to have "out of line" code because it doesn't fit.

Now that we are enabling MMU early in the prolog, take that opportunity
to jump somewhere else in the .text section where we don't have any
space constraint.

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/38b31ca4bc782a4985bc7952a675404d7ff27c24.1615552867.git.christophe.leroy@csgroup.eu
parent 7bf1d7e1

arch/powerpc/kernel/head_32.h

+5 −0
Original line number Diff line number Diff line
@@ -70,6 +70,8 @@ 
	mtspr	SPRN_SRR0, r11

	mfspr	r11, SPRN_SPRG_SCRATCH2

	rfi



	.text

1:

	stw	r11,GPR1(r1)

	stw	r11,0(r1)
@@ -163,12 +165,14 @@ 
 */

#ifdef CONFIG_PPC_BOOK3S

#define	START_EXCEPTION(n, label)		\

	__HEAD;					\

	. = n;					\

	DO_KVM n;				\

label:



#else

#define	START_EXCEPTION(n, label)		\

	__HEAD;					\

	. = n;					\

label:
@@ -196,6 +200,7 @@ 
			  ret_from_except)



.macro vmap_stack_overflow_exception

	__HEAD

vmap_stack_overflow:

#ifdef CONFIG_SMP

	mfspr	r1, SPRN_SPRG_THREAD

arch/powerpc/kernel/head_40x.S

+6 −0
Original line number Diff line number Diff line
@@ -132,6 +132,8 @@ _ENTRY(crit_esr) 
	ori	r11, r11, 1f@l

	mtspr	SPRN_SRR0, r11

	rfi



	.text

1:

	lwz	r11,crit_r1@l(0)

	stw	r11,GPR1(r1)
@@ -496,6 +498,7 @@ _ENTRY(crit_esr) 
		crit_transfer_to_handler, ret_from_crit_exc)



	/* Programmable Interval Timer (PIT) Exception. (from 0x1000) */

	__HEAD

Decrementer:

	EXCEPTION_PROLOG

	lis	r0,TSR_PIS@h
@@ -504,12 +507,14 @@ Decrementer: 
	EXC_XFER_LITE(0x1000, timer_interrupt)



	/* Fixed Interval Timer (FIT) Exception. (from 0x1010) */

	__HEAD

FITException:

	EXCEPTION_PROLOG

	addi	r3,r1,STACK_FRAME_OVERHEAD;

	EXC_XFER_STD(0x1010, unknown_exception)



	/* Watchdog Timer (WDT) Exception. (from 0x1020) */

	__HEAD

WDTException:

	CRITICAL_EXCEPTION_PROLOG;

	addi	r3,r1,STACK_FRAME_OVERHEAD;
@@ -523,6 +528,7 @@ WDTException: 
 * reserved.

 */



	__HEAD

	/* Damn, I came up one instruction too many to fit into the

	 * exception space :-).  Both the instruction and data TLB

	 * miss get to this point to load the TLB.

arch/powerpc/kernel/head_8xx.S

+10 −15
Original line number Diff line number Diff line
@@ -133,7 +133,7 @@ instruction_counter: 
	START_EXCEPTION(0x600, Alignment)

	EXCEPTION_PROLOG handle_dar_dsisr=1

	addi	r3,r1,STACK_FRAME_OVERHEAD

	b	.Lalignment_exception_ool

	EXC_XFER_STD(0x600, alignment_exception)



/* Program check exception */

	EXCEPTION(0x700, ProgramCheck, program_check_exception, EXC_XFER_STD)
@@ -141,11 +141,6 @@ instruction_counter: 
/* Decrementer */

	EXCEPTION(0x900, Decrementer, timer_interrupt, EXC_XFER_LITE)



	/* With VMAP_STACK there's not enough room for this at 0x600 */

	. = 0xa00

.Lalignment_exception_ool:

	EXC_XFER_STD(0x600, alignment_exception)



/* System call */

	START_EXCEPTION(0xc00, SystemCall)

	SYSCALL_ENTRY	0xc00
@@ -339,26 +334,25 @@ DARFixed:/* Return from dcbx instruction bug workaround */ 
 * support of breakpoints and such.  Someday I will get around to

 * using them.

 */

do_databreakpoint:

	EXCEPTION_PROLOG_1

	EXCEPTION_PROLOG_2 handle_dar_dsisr=1

	addi	r3,r1,STACK_FRAME_OVERHEAD

	mfspr	r4,SPRN_BAR

	stw	r4,_DAR(r11)

	EXC_XFER_STD(0x1c00, do_break)



	START_EXCEPTION(0x1c00, DataBreakpoint)

	EXCEPTION_PROLOG_0 handle_dar_dsisr=1

	mfspr	r11, SPRN_SRR0

	cmplwi	cr1, r11, (.Ldtlbie - PAGE_OFFSET)@l

	cmplwi	cr7, r11, (.Litlbie - PAGE_OFFSET)@l

	cror	4*cr1+eq, 4*cr1+eq, 4*cr7+eq

	bne	cr1, do_databreakpoint

	bne	cr1, 1f

	mtcr	r10

	mfspr	r10, SPRN_SPRG_SCRATCH0

	mfspr	r11, SPRN_SPRG_SCRATCH1

	rfi



1:	EXCEPTION_PROLOG_1

	EXCEPTION_PROLOG_2 handle_dar_dsisr=1

	addi	r3,r1,STACK_FRAME_OVERHEAD

	mfspr	r4,SPRN_BAR

	stw	r4,_DAR(r11)

	EXC_XFER_STD(0x1c00, do_break)



#ifdef CONFIG_PERF_EVENTS

	START_EXCEPTION(0x1d00, InstructionBreakpoint)

	mtspr	SPRN_SPRG_SCRATCH0, r10
@@ -376,6 +370,7 @@ do_databreakpoint: 
	EXCEPTION(0x1e00, Trap_1e, unknown_exception, EXC_XFER_STD)

	EXCEPTION(0x1f00, Trap_1f, unknown_exception, EXC_XFER_STD)



	__HEAD

	. = 0x2000



/* This is the procedure to calculate the data EA for buggy dcbx,dcbi instructions

arch/powerpc/kernel/head_book3s_32.S

+15 −19
Original line number Diff line number Diff line
@@ -269,11 +269,10 @@ __secondary_hold_acknowledge: 
7:	EXCEPTION_PROLOG_2

	addi	r3,r1,STACK_FRAME_OVERHEAD

#ifdef CONFIG_PPC_CHRP

	beq	cr1, machine_check_tramp

	beq	cr1, 1f

	twi	31, 0, 0

#else

	b	machine_check_tramp

#endif

1:	EXC_XFER_STD(0x200, machine_check_exception)



/* Data access exception. */

	START_EXCEPTION(0x300, DataAccess)
@@ -297,7 +296,13 @@ ALT_MMU_FTR_SECTION_END_IFSET(MMU_FTR_HPTE_TABLE) 
#endif

1:	EXCEPTION_PROLOG_0 handle_dar_dsisr=1

	EXCEPTION_PROLOG_1

	b	handle_page_fault_tramp_1

	EXCEPTION_PROLOG_2 handle_dar_dsisr=1

	lwz	r5, _DSISR(r11)

	andis.	r0, r5, DSISR_DABRMATCH@h

	bne-	1f

	EXC_XFER_LITE(0x300, handle_page_fault)

1:	EXC_XFER_STD(0x300, do_break)





/* Instruction access exception. */

	START_EXCEPTION(0x400, InstructionAccess)
@@ -333,7 +338,7 @@ END_MMU_FTR_SECTION_IFSET(MMU_FTR_HPTE_TABLE) 
	START_EXCEPTION(0x600, Alignment)

	EXCEPTION_PROLOG handle_dar_dsisr=1

	addi	r3,r1,STACK_FRAME_OVERHEAD

	b	alignment_exception_tramp

	EXC_XFER_STD(0x600, alignment_exception)



/* Program check exception */

	EXCEPTION(0x700, ProgramCheck, program_check_exception, EXC_XFER_STD)
@@ -385,6 +390,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_FPU_UNAVAILABLE) 
	START_EXCEPTION(0xf20, AltiVecUnavailableTrap)

	b	AltiVecUnavailable



	__HEAD

/*

 * Handle TLB miss for instruction on 603/603e.

 * Note: we get an alternate set of r0 - r3 to use automatically.
@@ -627,22 +633,9 @@ END_MMU_FTR_SECTION_IFSET(MMU_FTR_NEED_DTLB_SW_LRU) 
	EXCEPTION(0x2e00, Trap_2e, unknown_exception, EXC_XFER_STD)

	EXCEPTION(0x2f00, Trap_2f, unknown_exception, EXC_XFER_STD)



	__HEAD

	. = 0x3000



machine_check_tramp:

	EXC_XFER_STD(0x200, machine_check_exception)



alignment_exception_tramp:

	EXC_XFER_STD(0x600, alignment_exception)



handle_page_fault_tramp_1:

	EXCEPTION_PROLOG_2 handle_dar_dsisr=1

	lwz	r5, _DSISR(r11)

	andis.	r0, r5, DSISR_DABRMATCH@h

	bne-	1f

	EXC_XFER_LITE(0x300, handle_page_fault)

1:	EXC_XFER_STD(0x300, do_break)



#ifdef CONFIG_PPC_BOOK3S_604

.macro save_regs_thread		thread

	stw	r0, THR0(\thread)
@@ -721,6 +714,7 @@ fast_hash_page_return: 
	vmap_stack_overflow_exception

#endif



	__HEAD

AltiVecUnavailable:

	EXCEPTION_PROLOG

#ifdef CONFIG_ALTIVEC
@@ -731,12 +725,14 @@ AltiVecUnavailable: 
1:	addi	r3,r1,STACK_FRAME_OVERHEAD

	EXC_XFER_LITE(0xf20, altivec_unavailable_exception)



	__HEAD

PerformanceMonitor:

	EXCEPTION_PROLOG

	addi	r3,r1,STACK_FRAME_OVERHEAD

	EXC_XFER_STD(0xf00, performance_monitor_exception)





	__HEAD

/*

 * This code is jumped to from the startup code to copy

 * the kernel image to physical address PHYSICAL_START.