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Commit 47c0bd1a authored by Benjamin Herrenschmidt's avatar Benjamin Herrenschmidt Committed by Josh Boyer
Browse files

[POWERPC] Reworking machine check handling and Fix 440/440A 



This adds a cputable function pointer for the CPU-side machine
check handling. The semantic is still the same as the old one,
the one in ppc_md. overrides the one in cputable, though
ultimately we'll want to change that so the CPU gets first.

This removes CONFIG_440A which was a problem for multiplatform
kernels and instead fixes up the IVOR at runtime from a setup_cpu
function. The "A" version of the machine check also tweaks the
regs->trap value to differenciate the 2 versions at the C level.

Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: default avatarJosh Boyer <jwboyer@linux.vnet.ibm.com>
parent c2a7dcad

arch/powerpc/kernel/cpu_setup_44x.S

+9 −0
Original line number Diff line number Diff line
@@ -23,11 +23,20 @@ _GLOBAL(__setup_cpu_440epx) 
	mflr	r4

	bl	__init_fpu_44x

	bl	__plb_disable_wrp

	bl	__fixup_440A_mcheck

	mtlr	r4

	blr

_GLOBAL(__setup_cpu_440grx)

	b	__plb_disable_wrp

_GLOBAL(__setup_cpu_440gx)

_GLOBAL(__setup_cpu_440spe)

	b	__fixup_440A_mcheck



 /* Temporary fixup for arch/ppc until we kill the whole thing */

#ifndef CONFIG_PPC_MERGE

_GLOBAL(__fixup_440A_mcheck)

	blr

#endif



/* enable APU between CPU and FPU */

_GLOBAL(__init_fpu_44x)

arch/powerpc/kernel/cputable.c

+105 −0

File changed.

Preview size limit exceeded, changes collapsed.

arch/powerpc/kernel/head_44x.S

+10 −4
Original line number Diff line number Diff line
@@ -289,11 +289,8 @@ interrupt_base: 
	CRITICAL_EXCEPTION(0x0100, CriticalInput, unknown_exception)



	/* Machine Check Interrupt */

#ifdef CONFIG_440A

	MCHECK_EXCEPTION(0x0200, MachineCheck, machine_check_exception)

#else

	CRITICAL_EXCEPTION(0x0200, MachineCheck, machine_check_exception)

#endif

	MCHECK_EXCEPTION(0x0210, MachineCheckA, machine_check_exception)



	/* Data Storage Interrupt */

	START_EXCEPTION(DataStorage)
@@ -673,6 +670,15 @@ finish_tlb_load: 
 * Global functions

 */



/*

 * Adjust the machine check IVOR on 440A cores

 */

_GLOBAL(__fixup_440A_mcheck)

	li	r3,MachineCheckA@l

	mtspr	SPRN_IVOR1,r3

	sync

	blr



/*

 * extern void giveup_altivec(struct task_struct *prev)

 *

arch/powerpc/kernel/head_booke.h

+1 −1
Original line number Diff line number Diff line
@@ -166,7 +166,7 @@ label: 
	mfspr	r5,SPRN_ESR;					\

	stw	r5,_ESR(r11);					\

	addi	r3,r1,STACK_FRAME_OVERHEAD;			\

	EXC_XFER_TEMPLATE(hdlr, n+2, (MSR_KERNEL & ~(MSR_ME|MSR_DE|MSR_CE)), \

	EXC_XFER_TEMPLATE(hdlr, n+4, (MSR_KERNEL & ~(MSR_ME|MSR_DE|MSR_CE)), \

			  NOCOPY, mcheck_transfer_to_handler,   \

			  ret_from_mcheck_exc)

arch/powerpc/kernel/traps.c

+49 −13
Original line number Diff line number Diff line
@@ -334,18 +334,25 @@ static inline int check_io_access(struct pt_regs *regs) 
#define clear_single_step(regs)	((regs)->msr &= ~MSR_SE)

#endif



static int generic_machine_check_exception(struct pt_regs *regs)

#if defined(CONFIG_4xx)

int machine_check_4xx(struct pt_regs *regs)

{

	unsigned long reason = get_mc_reason(regs);



#if defined(CONFIG_4xx) && !defined(CONFIG_440A)

	if (reason & ESR_IMCP) {

		printk("Instruction");

		mtspr(SPRN_ESR, reason & ~ESR_IMCP);

	} else

		printk("Data");

	printk(" machine check in kernel mode.\n");

#elif defined(CONFIG_440A)



	return 0;

}



int machine_check_440A(struct pt_regs *regs)

{

	unsigned long reason = get_mc_reason(regs);



	printk("Machine check in kernel mode.\n");

	if (reason & ESR_IMCP){

		printk("Instruction Synchronous Machine Check exception\n");
@@ -375,7 +382,13 @@ static int generic_machine_check_exception(struct pt_regs *regs) 
		/* Clear MCSR */

		mtspr(SPRN_MCSR, mcsr);

	}

	return 0;

}

#elif defined(CONFIG_E500)

int machine_check_e500(struct pt_regs *regs)

{

	unsigned long reason = get_mc_reason(regs);



	printk("Machine check in kernel mode.\n");

	printk("Caused by (from MCSR=%lx): ", reason);
@@ -403,7 +416,14 @@ static int generic_machine_check_exception(struct pt_regs *regs) 
		printk("Bus - Instruction Parity Error\n");

	if (reason & MCSR_BUS_RPERR)

		printk("Bus - Read Parity Error\n");



	return 0;

}

#elif defined(CONFIG_E200)

int machine_check_e200(struct pt_regs *regs)

{

	unsigned long reason = get_mc_reason(regs);



	printk("Machine check in kernel mode.\n");

	printk("Caused by (from MCSR=%lx): ", reason);
@@ -421,7 +441,14 @@ static int generic_machine_check_exception(struct pt_regs *regs) 
		printk("Bus - Read Bus Error on data load\n");

	if (reason & MCSR_BUS_WRERR)

		printk("Bus - Write Bus Error on buffered store or cache line push\n");

#else /* !CONFIG_4xx && !CONFIG_E500 && !CONFIG_E200 */



	return 0;

}

#else

int machine_check_generic(struct pt_regs *regs)

{

	unsigned long reason = get_mc_reason(regs);



	printk("Machine check in kernel mode.\n");

	printk("Caused by (from SRR1=%lx): ", reason);

	switch (reason & 0x601F0000) {
@@ -451,22 +478,26 @@ static int generic_machine_check_exception(struct pt_regs *regs) 
	default:

		printk("Unknown values in msr\n");

	}

#endif /* CONFIG_4xx */



	return 0;

}

#endif /* everything else */



void machine_check_exception(struct pt_regs *regs)

{

	int recover = 0;



	/* See if any machine dependent calls */

	/* See if any machine dependent calls. In theory, we would want

	 * to call the CPU first, and call the ppc_md. one if the CPU

	 * one returns a positive number. However there is existing code

	 * that assumes the board gets a first chance, so let's keep it

	 * that way for now and fix things later. --BenH.

	 */

	if (ppc_md.machine_check_exception)

		recover = ppc_md.machine_check_exception(regs);

	else

		recover = generic_machine_check_exception(regs);

	else if (cur_cpu_spec->machine_check)

		recover = cur_cpu_spec->machine_check(regs);



	if (recover)

	if (recover > 0)

		return;



	if (user_mode(regs)) {
@@ -476,7 +507,12 @@ void machine_check_exception(struct pt_regs *regs) 
	}



#if defined(CONFIG_8xx) && defined(CONFIG_PCI)

	/* the qspan pci read routines can cause machine checks -- Cort */

	/* the qspan pci read routines can cause machine checks -- Cort

	 *

	 * yuck !!! that totally needs to go away ! There are better ways

	 * to deal with that than having a wart in the mcheck handler.

	 * -- BenH

	 */

	bad_page_fault(regs, regs->dar, SIGBUS);

	return;

#endif