From: Nicholas Piggin <npiggin@gmail.com>
To: linuxppc-dev@lists.ozlabs.org
Cc: Scott Wood <oss@buserror.net>, Nicholas Piggin <npiggin@gmail.com>
Subject: [PATCH v2 03/11] powerpc/interrupt: update common interrupt code for
Date: Tue, 16 Mar 2021 20:41:57 +1000 [thread overview]
Message-ID: <20210316104206.407354-4-npiggin@gmail.com> (raw)
In-Reply-To: <20210316104206.407354-1-npiggin@gmail.com>
This makes adjustments to 64-bit asm and common C interrupt return
code to be usable by the 64e subarchitecture.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
arch/powerpc/kernel/entry_64.S | 9 +++++++--
arch/powerpc/kernel/interrupt.c | 35 ++++++++++++++++++++-------------
2 files changed, 28 insertions(+), 16 deletions(-)
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 853534b2ae2e..555b3d0a3f38 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -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
/*
diff --git a/arch/powerpc/kernel/interrupt.c b/arch/powerpc/kernel/interrupt.c
index fbabb49888d3..381a618b5b5b 100644
--- a/arch/powerpc/kernel/interrupt.c
+++ b/arch/powerpc/kernel/interrupt.c
@@ -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
--
2.23.0
next prev parent reply other threads:[~2021-03-16 10:44 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-16 10:41 [PATCH v2 00/11] Move 64e to new interrupt return code Nicholas Piggin
2021-03-16 10:41 ` [PATCH v2 01/11] powerpc/syscall: switch user_exit_irqoff and trace_hardirqs_off order Nicholas Piggin
2021-03-16 10:41 ` [PATCH v2 02/11] powerpc/64e/interrupt: always save nvgprs on interrupt Nicholas Piggin
2021-03-16 10:41 ` Nicholas Piggin [this message]
2021-03-16 10:41 ` [PATCH v2 04/11] powerpc/64e/interrupt: use new interrupt return Nicholas Piggin
2021-03-16 10:49 ` Christophe Leroy
2021-03-17 10:05 ` Nicholas Piggin
2021-03-16 10:41 ` [PATCH v2 05/11] powerpc/64e/interrupt: NMI save irq soft-mask state in C Nicholas Piggin
2021-03-16 10:42 ` [PATCH v2 06/11] powerpc/64e/interrupt: reconcile " Nicholas Piggin
2021-03-16 10:42 ` [PATCH v2 07/11] powerpc/64e/interrupt: Use new interrupt context tracking scheme Nicholas Piggin
2021-03-16 10:42 ` [PATCH v2 08/11] powerpc/64e/interrupt: handle bad_page_fault in C Nicholas Piggin
2021-03-16 10:42 ` [PATCH v2 09/11] powerpc: clean up do_page_fault Nicholas Piggin
2021-03-16 10:42 ` [PATCH v2 10/11] powerpc: remove partial register save logic Nicholas Piggin
2021-03-16 10:42 ` [PATCH v2 11/11] powerpc: move norestart trap flag to bit 0 Nicholas Piggin
2021-04-19 4:00 ` [PATCH v2 00/11] Move 64e to new interrupt return code Michael Ellerman
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