[PATCH 08/18] powerpc/64: context tracking move to interrupt wrappers

Nicholas Piggin npiggin at gmail.com
Fri Nov 6 01:34:21 AEDT 2020


This moves exception_enter/exit calls to wrapper functions for
synchronous interrupts. More interrupt handlers are covered by
this than previously.

Signed-off-by: Nicholas Piggin <npiggin at gmail.com>
---
 arch/powerpc/include/asm/interrupt.h  |  9 ++++
 arch/powerpc/kernel/traps.c           | 74 ++++++---------------------
 arch/powerpc/mm/book3s64/hash_utils.c |  2 -
 arch/powerpc/mm/fault.c               |  3 --
 4 files changed, 26 insertions(+), 62 deletions(-)

diff --git a/arch/powerpc/include/asm/interrupt.h b/arch/powerpc/include/asm/interrupt.h
index 446e24b0eee1..62a362915adc 100644
--- a/arch/powerpc/include/asm/interrupt.h
+++ b/arch/powerpc/include/asm/interrupt.h
@@ -7,14 +7,23 @@
 #include <asm/ftrace.h>
 
 struct interrupt_state {
+#ifdef CONFIG_PPC64
+	enum ctx_state ctx_state;
+#endif
 };
 
 static inline void interrupt_enter_prepare(struct pt_regs *regs, struct interrupt_state *state)
 {
+#ifdef CONFIG_PPC64
+	state->ctx_state = exception_enter();
+#endif
 }
 
 static inline void interrupt_exit_prepare(struct pt_regs *regs, struct interrupt_state *state)
 {
+#ifdef CONFIG_PPC64
+	exception_exit(state->ctx_state);
+#endif
 }
 
 static inline void interrupt_async_enter_prepare(struct pt_regs *regs, struct interrupt_state *state)
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index 2d19df1f6c05..09780481e1b1 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -1108,41 +1108,28 @@ DEFINE_INTERRUPT_HANDLER_ASYNC(handle_hmi_exception)
 
 DEFINE_INTERRUPT_HANDLER(unknown_exception)
 {
-	enum ctx_state prev_state = exception_enter();
-
 	printk("Bad trap at PC: %lx, SR: %lx, vector=%lx\n",
 	       regs->nip, regs->msr, regs->trap);
 
 	_exception(SIGTRAP, regs, TRAP_UNK, 0);
-
-	exception_exit(prev_state);
 }
 
 DEFINE_INTERRUPT_HANDLER_ASYNC(unknown_async_exception)
 {
-	enum ctx_state prev_state = exception_enter();
-
 	printk("Bad trap at PC: %lx, SR: %lx, vector=%lx\n",
 	       regs->nip, regs->msr, regs->trap);
 
 	_exception(SIGTRAP, regs, TRAP_UNK, 0);
-
-	exception_exit(prev_state);
 }
 
 DEFINE_INTERRUPT_HANDLER(instruction_breakpoint_exception)
 {
-	enum ctx_state prev_state = exception_enter();
-
 	if (notify_die(DIE_IABR_MATCH, "iabr_match", regs, 5,
 					5, SIGTRAP) == NOTIFY_STOP)
-		goto bail;
+		return;
 	if (debugger_iabr_match(regs))
-		goto bail;
+		return;
 	_exception(SIGTRAP, regs, TRAP_BRKPT, regs->nip);
-
-bail:
-	exception_exit(prev_state);
 }
 
 DEFINE_INTERRUPT_HANDLER(RunModeException)
@@ -1152,8 +1139,6 @@ DEFINE_INTERRUPT_HANDLER(RunModeException)
 
 DEFINE_INTERRUPT_HANDLER(single_step_exception)
 {
-	enum ctx_state prev_state = exception_enter();
-
 	clear_single_step(regs);
 	clear_br_trace(regs);
 
@@ -1162,14 +1147,11 @@ DEFINE_INTERRUPT_HANDLER(single_step_exception)
 
 	if (notify_die(DIE_SSTEP, "single_step", regs, 5,
 					5, SIGTRAP) == NOTIFY_STOP)
-		goto bail;
+		return;
 	if (debugger_sstep(regs))
-		goto bail;
+		return;
 
 	_exception(SIGTRAP, regs, TRAP_TRACE, regs->nip);
-
-bail:
-	exception_exit(prev_state);
 }
 NOKPROBE_SYMBOL(single_step_exception);
 
@@ -1495,7 +1477,6 @@ static inline int emulate_math(struct pt_regs *regs) { return -1; }
 
 DEFINE_INTERRUPT_HANDLER(program_check_exception)
 {
-	enum ctx_state prev_state = exception_enter();
 	unsigned int reason = get_reason(regs);
 
 	/* We can now get here via a FP Unavailable exception if the core
@@ -1504,22 +1485,22 @@ DEFINE_INTERRUPT_HANDLER(program_check_exception)
 	if (reason & REASON_FP) {
 		/* IEEE FP exception */
 		parse_fpe(regs);
-		goto bail;
+		return;
 	}
 	if (reason & REASON_TRAP) {
 		unsigned long bugaddr;
 		/* Debugger is first in line to stop recursive faults in
 		 * rcu_lock, notify_die, or atomic_notifier_call_chain */
 		if (debugger_bpt(regs))
-			goto bail;
+			return;
 
 		if (kprobe_handler(regs))
-			goto bail;
+			return;
 
 		/* trap exception */
 		if (notify_die(DIE_BPT, "breakpoint", regs, 5, 5, SIGTRAP)
 				== NOTIFY_STOP)
-			goto bail;
+			return;
 
 		bugaddr = regs->nip;
 		/*
@@ -1531,10 +1512,10 @@ DEFINE_INTERRUPT_HANDLER(program_check_exception)
 		if (!(regs->msr & MSR_PR) &&  /* not user-mode */
 		    report_bug(bugaddr, regs) == BUG_TRAP_TYPE_WARN) {
 			regs->nip += 4;
-			goto bail;
+			return;
 		}
 		_exception(SIGTRAP, regs, TRAP_BRKPT, regs->nip);
-		goto bail;
+		return;
 	}
 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 	if (reason & REASON_TM) {
@@ -1555,7 +1536,7 @@ DEFINE_INTERRUPT_HANDLER(program_check_exception)
 		 */
 		if (user_mode(regs)) {
 			_exception(SIGILL, regs, ILL_ILLOPN, regs->nip);
-			goto bail;
+			return;
 		} else {
 			printk(KERN_EMERG "Unexpected TM Bad Thing exception "
 			       "at %lx (msr 0x%lx) tm_scratch=%llx\n",
@@ -1586,7 +1567,7 @@ DEFINE_INTERRUPT_HANDLER(program_check_exception)
 	 * pattern to occurrences etc. -dgibson 31/Mar/2003
 	 */
 	if (!emulate_math(regs))
-		goto bail;
+		return;
 
 	/* Try to emulate it if we should. */
 	if (reason & (REASON_ILLEGAL | REASON_PRIVILEGED)) {
@@ -1594,10 +1575,10 @@ DEFINE_INTERRUPT_HANDLER(program_check_exception)
 		case 0:
 			regs->nip += 4;
 			emulate_single_step(regs);
-			goto bail;
+			return;
 		case -EFAULT:
 			_exception(SIGSEGV, regs, SEGV_MAPERR, regs->nip);
-			goto bail;
+			return;
 		}
 	}
 
@@ -1606,9 +1587,6 @@ DEFINE_INTERRUPT_HANDLER(program_check_exception)
 		_exception(SIGILL, regs, ILL_PRVOPC, regs->nip);
 	else
 		_exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
-
-bail:
-	exception_exit(prev_state);
 }
 NOKPROBE_SYMBOL(program_check_exception);
 
@@ -1625,14 +1603,12 @@ NOKPROBE_SYMBOL(emulation_assist_interrupt);
 
 DEFINE_INTERRUPT_HANDLER(alignment_exception)
 {
-	enum ctx_state prev_state = exception_enter();
 	int sig, code, fixed = 0;
 	unsigned long  reason;
 
 	interrupt_cond_local_irq_enable(regs);
 
 	reason = get_reason(regs);
-
 	if (reason & REASON_BOUNDARY) {
 		sig = SIGBUS;
 		code = BUS_ADRALN;
@@ -1640,7 +1616,7 @@ DEFINE_INTERRUPT_HANDLER(alignment_exception)
 	}
 
 	if (tm_abort_check(regs, TM_CAUSE_ALIGNMENT | TM_CAUSE_PERSISTENT))
-		goto bail;
+		return;
 
 	/* we don't implement logging of alignment exceptions */
 	if (!(current->thread.align_ctl & PR_UNALIGN_SIGBUS))
@@ -1650,7 +1626,7 @@ DEFINE_INTERRUPT_HANDLER(alignment_exception)
 		/* skip over emulated instruction */
 		regs->nip += inst_length(reason);
 		emulate_single_step(regs);
-		goto bail;
+		return;
 	}
 
 	/* Operand address was bad */
@@ -1666,9 +1642,6 @@ DEFINE_INTERRUPT_HANDLER(alignment_exception)
 		_exception(sig, regs, code, regs->dar);
 	else
 		bad_page_fault(regs, sig);
-
-bail:
-	exception_exit(prev_state);
 }
 
 DEFINE_INTERRUPT_HANDLER(StackOverflow)
@@ -1682,41 +1655,28 @@ DEFINE_INTERRUPT_HANDLER(StackOverflow)
 
 DEFINE_INTERRUPT_HANDLER(stack_overflow_exception)
 {
-	enum ctx_state prev_state = exception_enter();
-
 	die("Kernel stack overflow", regs, SIGSEGV);
-
-	exception_exit(prev_state);
 }
 
 DEFINE_INTERRUPT_HANDLER(kernel_fp_unavailable_exception)
 {
-	enum ctx_state prev_state = exception_enter();
-
 	printk(KERN_EMERG "Unrecoverable FP Unavailable Exception "
 			  "%lx at %lx\n", regs->trap, regs->nip);
 	die("Unrecoverable FP Unavailable Exception", regs, SIGABRT);
-
-	exception_exit(prev_state);
 }
 
 DEFINE_INTERRUPT_HANDLER(altivec_unavailable_exception)
 {
-	enum ctx_state prev_state = exception_enter();
-
 	if (user_mode(regs)) {
 		/* A user program has executed an altivec instruction,
 		   but this kernel doesn't support altivec. */
 		_exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
-		goto bail;
+		return;
 	}
 
 	printk(KERN_EMERG "Unrecoverable VMX/Altivec Unavailable Exception "
 			"%lx at %lx\n", regs->trap, regs->nip);
 	die("Unrecoverable VMX/Altivec Unavailable Exception", regs, SIGABRT);
-
-bail:
-	exception_exit(prev_state);
 }
 
 DEFINE_INTERRUPT_HANDLER(vsx_unavailable_exception)
diff --git a/arch/powerpc/mm/book3s64/hash_utils.c b/arch/powerpc/mm/book3s64/hash_utils.c
index a48c484b9e9b..39dcfaf7ba36 100644
--- a/arch/powerpc/mm/book3s64/hash_utils.c
+++ b/arch/powerpc/mm/book3s64/hash_utils.c
@@ -1289,7 +1289,6 @@ int hash_page_mm(struct mm_struct *mm, unsigned long ea,
 		 unsigned long flags)
 {
 	bool is_thp;
-	enum ctx_state prev_state = exception_enter();
 	pgd_t *pgdir;
 	unsigned long vsid;
 	pte_t *ptep;
@@ -1489,7 +1488,6 @@ int hash_page_mm(struct mm_struct *mm, unsigned long ea,
 	DBG_LOW(" -> rc=%d\n", rc);
 
 bail:
-	exception_exit(prev_state);
 	return rc;
 }
 EXPORT_SYMBOL_GPL(hash_page_mm);
diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c
index fd0c56c80c3c..4cc265e0364d 100644
--- a/arch/powerpc/mm/fault.c
+++ b/arch/powerpc/mm/fault.c
@@ -550,7 +550,6 @@ NOKPROBE_SYMBOL(__do_page_fault);
 
 DEFINE_INTERRUPT_HANDLER_RET(do_page_fault)
 {
-	enum ctx_state prev_state = exception_enter();
 	unsigned long address = regs->dar;
 	unsigned long error_code = regs->dsisr;
 	long err;
@@ -573,8 +572,6 @@ DEFINE_INTERRUPT_HANDLER_RET(do_page_fault)
 	}
 #endif
 
-	exception_exit(prev_state);
-
 	return err;
 }
 NOKPROBE_SYMBOL(do_page_fault);
-- 
2.23.0



More information about the Linuxppc-dev mailing list