linux-kernel - [PATCH v3 2/5] powerpc/interrupt: Refactor interrupt_exit_user

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Date:   Tue, 15 Jun 2021 08:33:22 +0000 (UTC)
From:   Christophe Leroy <christophe.leroy@...roup.eu>
To:     Benjamin Herrenschmidt <benh@...nel.crashing.org>,
        Paul Mackerras <paulus@...ba.org>,
        Michael Ellerman <mpe@...erman.id.au>, npiggin@...il.com
Cc:     linux-kernel@...r.kernel.org, linuxppc-dev@...ts.ozlabs.org
Subject: [PATCH v3 2/5] powerpc/interrupt: Refactor
 interrupt_exit_user_prepare()

interrupt_exit_user_prepare() is a superset of
interrupt_exit_user_prepare_main().

Refactor to avoid code duplication.

Signed-off-by: Christophe Leroy <christophe.leroy@...roup.eu>
---
 arch/powerpc/kernel/interrupt.c | 57 ++-------------------------------
 1 file changed, 3 insertions(+), 54 deletions(-)

diff --git a/arch/powerpc/kernel/interrupt.c b/arch/powerpc/kernel/interrupt.c
index ba2d602d2da6..b9558372adc0 100644
--- a/arch/powerpc/kernel/interrupt.c
+++ b/arch/powerpc/kernel/interrupt.c
@@ -400,9 +400,7 @@ notrace unsigned long syscall_exit_restart(unsigned long r3, struct pt_regs *reg
 
 notrace unsigned long interrupt_exit_user_prepare(struct pt_regs *regs)
 {
-	unsigned long ti_flags;
-	unsigned long flags;
-	unsigned long ret = 0;
+	unsigned long ret;
 
 	if (!IS_ENABLED(CONFIG_BOOKE) && !IS_ENABLED(CONFIG_40x))
 		BUG_ON(!(regs->msr & MSR_RI));
@@ -416,63 +414,14 @@ notrace unsigned long interrupt_exit_user_prepare(struct pt_regs *regs)
 	 */
 	kuap_assert_locked();
 
-	local_irq_save(flags);
-
-again:
-	ti_flags = READ_ONCE(current_thread_info()->flags);
-	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) {
-			schedule();
-		} else {
-			if (ti_flags & _TIF_SIGPENDING)
-				ret |= _TIF_RESTOREALL;
-			do_notify_resume(regs, ti_flags);
-		}
-		local_irq_disable();
-		ti_flags = READ_ONCE(current_thread_info()->flags);
-	}
-
-	if (IS_ENABLED(CONFIG_PPC_BOOK3S_64) && IS_ENABLED(CONFIG_PPC_FPU)) {
-		if (IS_ENABLED(CONFIG_PPC_TRANSACTIONAL_MEM) &&
-				unlikely((ti_flags & _TIF_RESTORE_TM))) {
-			restore_tm_state(regs);
-		} else {
-			unsigned long mathflags = MSR_FP;
-
-			if (cpu_has_feature(CPU_FTR_VSX))
-				mathflags |= MSR_VEC | MSR_VSX;
-			else if (cpu_has_feature(CPU_FTR_ALTIVEC))
-				mathflags |= MSR_VEC;
-
-			/* See above restore_math comment */
-			if ((regs->msr & mathflags) != mathflags)
-				restore_math(regs);
-		}
-	}
-
-	if (!prep_irq_for_user_exit()) {
-		local_irq_enable();
-		local_irq_disable();
-		goto again;
-	}
-
-	booke_load_dbcr0();
-
-#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
-	local_paca->tm_scratch = regs->msr;
-#endif
+	local_irq_disable();
 
-	account_cpu_user_exit();
+	ret = interrupt_exit_user_prepare_main(regs, 0);
 
 #ifdef CONFIG_PPC64
 	regs->exit_result = ret;
 #endif
 
-	/* Restore user access locks last */
-	kuap_user_restore(regs);
-	kuep_unlock();
-
 	return ret;
 }
 
-- 
2.25.0