Commit dc623182 authored by Nicholas Piggin's avatar Nicholas Piggin Committed by Michael Ellerman
Browse files

powerpc/interrupt: update common interrupt code for 



This makes adjustments to 64-bit asm and common C interrupt return
code to be usable by the 64e subarchitecture.

Signed-off-by: default avatarNicholas Piggin <npiggin@gmail.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210316104206.407354-4-npiggin@gmail.com
parent 4228b2c3

arch/powerpc/kernel/entry_64.S

+7 −2
Original line number Diff line number Diff line
@@ -632,7 +632,6 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_207S) 
	addi	r1,r1,SWITCH_FRAME_SIZE

	blr



#ifdef CONFIG_PPC_BOOK3S

	/*

	 * If MSR EE/RI was never enabled, IRQs not reconciled, NVGPRs not

	 * touched, no exit work created, then this can be used.
@@ -644,6 +643,7 @@ _ASM_NOKPROBE_SYMBOL(fast_interrupt_return) 
	kuap_check_amr r3, r4

	ld	r5,_MSR(r1)

	andi.	r0,r5,MSR_PR

#ifdef CONFIG_PPC_BOOK3S

	bne	.Lfast_user_interrupt_return_amr

	kuap_kernel_restore r3, r4

	andi.	r0,r5,MSR_RI
@@ -652,6 +652,10 @@ _ASM_NOKPROBE_SYMBOL(fast_interrupt_return) 
	addi	r3,r1,STACK_FRAME_OVERHEAD

	bl	unrecoverable_exception

	b	. /* should not get here */

#else

	bne	.Lfast_user_interrupt_return

	b	.Lfast_kernel_interrupt_return

#endif



	.balign IFETCH_ALIGN_BYTES

	.globl interrupt_return
@@ -665,8 +669,10 @@ _ASM_NOKPROBE_SYMBOL(interrupt_return) 
	cmpdi	r3,0

	bne-	.Lrestore_nvgprs



#ifdef CONFIG_PPC_BOOK3S

.Lfast_user_interrupt_return_amr:

	kuap_user_restore r3, r4

#endif

.Lfast_user_interrupt_return:

	ld	r11,_NIP(r1)

	ld	r12,_MSR(r1)
@@ -775,7 +781,6 @@ ALT_FTR_SECTION_END_IFCLR(CPU_FTR_STCX_CHECKS_ADDRESS) 


	RFI_TO_KERNEL

	b	.	/* prevent speculative execution */

#endif /* CONFIG_PPC_BOOK3S */



#ifdef CONFIG_PPC_RTAS

/*

arch/powerpc/kernel/interrupt.c

+21 −14
Original line number Diff line number Diff line
@@ -235,6 +235,10 @@ static notrace void booke_load_dbcr0(void) 
#endif

}



/* temporary hack for context tracking, removed in later patch */

#include <linux/sched/debug.h>

asmlinkage __visible void __sched schedule_user(void);



/*

 * This should be called after a syscall returns, with r3 the return value

 * from the syscall. If this function returns non-zero, the system call
@@ -292,7 +296,11 @@ notrace unsigned long syscall_exit_prepare(unsigned long r3, 
	while (unlikely(ti_flags & (_TIF_USER_WORK_MASK & ~_TIF_RESTORE_TM))) {

		local_irq_enable();

		if (ti_flags & _TIF_NEED_RESCHED) {

#ifdef CONFIG_PPC_BOOK3E_64

			schedule_user();

#else

			schedule();

#endif

		} else {

			/*

			 * SIGPENDING must restore signal handler function
@@ -349,18 +357,13 @@ notrace unsigned long syscall_exit_prepare(unsigned long r3, 


	account_cpu_user_exit();



#ifndef CONFIG_PPC_BOOK3E_64 /* BOOK3E not using this */

	/*

	 * We do this at the end so that we do context switch with KERNEL AMR

	 */

	/* Restore user access locks last */

	kuap_user_restore(regs);

#endif

	kuep_unlock();



	return ret;

}



#ifndef CONFIG_PPC_BOOK3E_64 /* BOOK3E not yet using this */

notrace unsigned long interrupt_exit_user_prepare(struct pt_regs *regs, unsigned long msr)

{

	unsigned long ti_flags;
@@ -372,7 +375,9 @@ notrace unsigned long interrupt_exit_user_prepare(struct pt_regs *regs, unsigned 
	BUG_ON(!(regs->msr & MSR_PR));

	BUG_ON(!FULL_REGS(regs));

	BUG_ON(arch_irq_disabled_regs(regs));

#ifdef CONFIG_PPC_BOOK3S_64

	CT_WARN_ON(ct_state() == CONTEXT_USER);

#endif



	/*

	 * We don't need to restore AMR on the way back to userspace for KUAP.
@@ -387,7 +392,11 @@ notrace unsigned long interrupt_exit_user_prepare(struct pt_regs *regs, unsigned 
	while (unlikely(ti_flags & (_TIF_USER_WORK_MASK & ~_TIF_RESTORE_TM))) {

		local_irq_enable(); /* returning to user: may enable */

		if (ti_flags & _TIF_NEED_RESCHED) {

#ifdef CONFIG_PPC_BOOK3E_64

			schedule_user();

#else

			schedule();

#endif

		} else {

			if (ti_flags & _TIF_SIGPENDING)

				ret |= _TIF_RESTOREALL;
@@ -432,10 +441,9 @@ notrace unsigned long interrupt_exit_user_prepare(struct pt_regs *regs, unsigned 


	account_cpu_user_exit();



	/*

	 * We do this at the end so that we do context switch with KERNEL AMR

	 */

	/* Restore user access locks last */

	kuap_user_restore(regs);



	return ret;

}
@@ -456,7 +464,7 @@ notrace unsigned long interrupt_exit_kernel_prepare(struct pt_regs *regs, unsign 
	 * CT_WARN_ON comes here via program_check_exception,

	 * so avoid recursion.

	 */

	if (TRAP(regs) != 0x700)

	if (IS_ENABLED(CONFIG_BOOKS) && TRAP(regs) != 0x700)

		CT_WARN_ON(ct_state() == CONTEXT_USER);



	kuap = kuap_get_and_assert_locked();
@@ -497,12 +505,11 @@ notrace unsigned long interrupt_exit_kernel_prepare(struct pt_regs *regs, unsign 
#endif



	/*

	 * Don't want to mfspr(SPRN_AMR) here, because this comes after mtmsr,

	 * which would cause Read-After-Write stalls. Hence, we take the AMR

	 * value from the check above.

	 * 64s does not want to mfspr(SPRN_AMR) here, because this comes after

	 * mtmsr, which would cause Read-After-Write stalls. Hence, take the

	 * AMR value from the check above.

	 */

	kuap_kernel_restore(regs, kuap);



	return ret;

}
 
#endif