Merge tag 'for-5.16/parisc-2' of git://git.kernel.org/pub/scm/linux/k…

…ernel/git/deller/parisc-linux

Pull more parisc architecture fixes and updates from Helge Deller:
 "One build error fix and two optimizations:

   - Fix build error by moving the CPU field back into thread_info
     struct (Ard Biesheuvel)

   - Do not enable IRQs unconditionally at start of interrupt handler if
     they were disabled before (Sven Schnelle)

   - Keep interrupts enabled during cmpxchg and futex operations (Dave
     Anglin)"

* tag 'for-5.16/parisc-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: move CPU field back into thread_info
  parisc: Don't disable interrupts in cmpxchg and futex operations
  parisc: don't enable irqs unconditionally in handle_interruption()

arch/parisc/include/asm/futex.h

@@ -11,35 +11,34 @@
    sixteen four-word locks. */
 
 static inline void
-_futex_spin_lock_irqsave(u32 __user *uaddr, unsigned long int *flags)
+_futex_spin_lock(u32 __user *uaddr)
 {
 	extern u32 lws_lock_start[];
 	long index = ((long)uaddr & 0x3f8) >> 1;
 	arch_spinlock_t *s = (arch_spinlock_t *)&lws_lock_start[index];
-	local_irq_save(*flags);
+	preempt_disable();
 	arch_spin_lock(s);
 }
 
 static inline void
-_futex_spin_unlock_irqrestore(u32 __user *uaddr, unsigned long int *flags)
+_futex_spin_unlock(u32 __user *uaddr)
 {
 	extern u32 lws_lock_start[];
 	long index = ((long)uaddr & 0x3f8) >> 1;
 	arch_spinlock_t *s = (arch_spinlock_t *)&lws_lock_start[index];
 	arch_spin_unlock(s);
-	local_irq_restore(*flags);
+	preempt_enable();
 }
 
 static inline int
 arch_futex_atomic_op_inuser(int op, int oparg, int *oval, u32 __user *uaddr)
 {
-	unsigned long int flags;
 	int oldval, ret;
 	u32 tmp;
 
-	_futex_spin_lock_irqsave(uaddr, &flags);
-
 	ret = -EFAULT;
+
+	_futex_spin_lock(uaddr);
 	if (unlikely(get_user(oldval, uaddr) != 0))
 		goto out_pagefault_enable;
 
@@ -70,7 +69,7 @@ arch_futex_atomic_op_inuser(int op, int oparg, int *oval, u32 __user *uaddr)
 		ret = -EFAULT;
 
 out_pagefault_enable:
-	_futex_spin_unlock_irqrestore(uaddr, &flags);
+	_futex_spin_unlock(uaddr);
 
 	if (!ret)
 		*oval = oldval;
@@ -83,7 +82,6 @@ futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
 			      u32 oldval, u32 newval)
 {
 	u32 val;
-	unsigned long flags;
 
 	/* futex.c wants to do a cmpxchg_inatomic on kernel NULL, which is
 	 * our gateway page, and causes no end of trouble...
@@ -100,19 +98,19 @@ futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
 	 * address. This should scale to a couple of CPUs.
 	 */
 
-	_futex_spin_lock_irqsave(uaddr, &flags);
+	_futex_spin_lock(uaddr);
 	if (unlikely(get_user(val, uaddr) != 0)) {
-		_futex_spin_unlock_irqrestore(uaddr, &flags);
+		_futex_spin_unlock(uaddr);
 		return -EFAULT;
 	}
 
 	if (val == oldval && unlikely(put_user(newval, uaddr) != 0)) {
-		_futex_spin_unlock_irqrestore(uaddr, &flags);
+		_futex_spin_unlock(uaddr);
 		return -EFAULT;
 	}
 
 	*uval = val;
-	_futex_spin_unlock_irqrestore(uaddr, &flags);
+	_futex_spin_unlock(uaddr);
 
 	return 0;
 }

arch/parisc/include/asm/smp.h

@@ -32,25 +32,10 @@ extern void smp_send_all_nop(void);
 extern void arch_send_call_function_single_ipi(int cpu);
 extern void arch_send_call_function_ipi_mask(const struct cpumask *mask);
 
+#define raw_smp_processor_id()		(current_thread_info()->cpu)
+
 #endif /* !ASSEMBLY */
 
-/*
- * This is particularly ugly: it appears we can't actually get the definition
- * of task_struct here, but we need access to the CPU this task is running on.
- * Instead of using task_struct we're using TASK_CPU which is extracted from
- * asm-offsets.h by kbuild to get the current processor ID.
- *
- * This also needs to be safeguarded when building asm-offsets.s because at
- * that time TASK_CPU is not defined yet. It could have been guarded by
- * TASK_CPU itself, but we want the build to fail if TASK_CPU is missing
- * when building something else than asm-offsets.s
- */
-#ifdef GENERATING_ASM_OFFSETS
-#define raw_smp_processor_id()		(0)
-#else
-#include <asm/asm-offsets.h>
-#define raw_smp_processor_id()		(*(unsigned int *)((void *)current + TASK_CPU))
-#endif
 #else /* CONFIG_SMP */
 
 static inline void smp_send_all_nop(void) { return; }

arch/parisc/include/asm/thread_info.h

@@ -9,6 +9,9 @@
 struct thread_info {
 	unsigned long flags;		/* thread_info flags (see TIF_*) */
 	int preempt_count;		/* 0=premptable, <0=BUG; will also serve as bh-counter */
+#ifdef CONFIG_SMP
+	unsigned int cpu;
+#endif
 };
 
 #define INIT_THREAD_INFO(tsk)			\

arch/parisc/kernel/asm-offsets.c

@@ -14,8 +14,6 @@
  *    Copyright (C) 2003 James Bottomley <jejb at parisc-linux.org>
  */
 
-#define GENERATING_ASM_OFFSETS /* asm/smp.h */
-
 #include <linux/types.h>
 #include <linux/sched.h>
 #include <linux/thread_info.h>
@@ -39,9 +37,6 @@ int main(void)
 {
 	DEFINE(TASK_TI_FLAGS, offsetof(struct task_struct, thread_info.flags));
 	DEFINE(TASK_STACK, offsetof(struct task_struct, stack));
-#ifdef CONFIG_SMP
-	DEFINE(TASK_CPU, offsetof(struct task_struct, cpu));
-#endif
 	BLANK();
 	DEFINE(TASK_REGS, offsetof(struct task_struct, thread.regs));
 	DEFINE(TASK_PT_PSW, offsetof(struct task_struct, thread.regs.gr[ 0]));

arch/parisc/kernel/smp.c

@@ -339,8 +339,6 @@ int smp_boot_one_cpu(int cpuid, struct task_struct *idle)
 	const struct cpuinfo_parisc *p = &per_cpu(cpu_data, cpuid);
 	long timeout;
 
-	idle->cpu = cpuid;
-
 	/* Let _start know what logical CPU we're booting
 	** (offset into init_tasks[],cpu_data[])
 	*/

arch/parisc/kernel/syscall.S

@@ -597,13 +597,11 @@ cas_nocontend:
 # endif
 /* ENABLE_LWS_DEBUG */
 
-	rsm	PSW_SM_I, %r0				/* Disable interrupts */
 	/* COW breaks can cause contention on UP systems */
 	LDCW	0(%sr2,%r20), %r28			/* Try to acquire the lock */
 	cmpb,<>,n	%r0, %r28, cas_action		/* Did we get it? */
 cas_wouldblock:
 	ldo	2(%r0), %r28				/* 2nd case */
-	ssm	PSW_SM_I, %r0
 	b	lws_exit				/* Contended... */
 	ldo	-EAGAIN(%r0), %r21			/* Spin in userspace */
 
@@ -639,8 +637,6 @@ cas_action:
 	/* Clear thread register indicator */
 	stw	%r0, 4(%sr2,%r20)
 #endif
-	/* Enable interrupts */
-	ssm	PSW_SM_I, %r0
 	/* Return to userspace, set no error */
 	b	lws_exit
 	copy	%r0, %r21
@@ -652,7 +648,6 @@ cas_action:
 #if ENABLE_LWS_DEBUG
 	stw	%r0, 4(%sr2,%r20)
 #endif
-	ssm	PSW_SM_I, %r0
 	b	lws_exit
 	ldo	-EFAULT(%r0),%r21	/* set errno */
 	nop
@@ -764,13 +759,11 @@ cas2_lock_start:
 	shlw	%r20, 4, %r20
 	add	%r20, %r28, %r20
 
-	rsm	PSW_SM_I, %r0			/* Disable interrupts */
 	/* COW breaks can cause contention on UP systems */
 	LDCW	0(%sr2,%r20), %r28		/* Try to acquire the lock */
 	cmpb,<>,n	%r0, %r28, cas2_action	/* Did we get it? */
 cas2_wouldblock:
 	ldo	2(%r0), %r28			/* 2nd case */
-	ssm	PSW_SM_I, %r0
 	b	lws_exit			/* Contended... */
 	ldo	-EAGAIN(%r0), %r21		/* Spin in userspace */
 
@@ -850,8 +843,6 @@ cas2_action:
 cas2_end:
 	/* Free lock */
 	stw,ma	%r20, 0(%sr2,%r20)
-	/* Enable interrupts */
-	ssm	PSW_SM_I, %r0
 	/* Return to userspace, set no error */
 	b	lws_exit
 	copy	%r0, %r21
@@ -860,7 +851,6 @@ cas2_end:
 	/* Error occurred on load or store */
 	/* Free lock */
 	stw,ma	%r20, 0(%sr2,%r20)
-	ssm	PSW_SM_I, %r0
 	ldo	1(%r0),%r28
 	b	lws_exit
 	ldo	-EFAULT(%r0),%r21	/* set errno */

arch/parisc/kernel/traps.c

@@ -481,7 +481,7 @@ void notrace handle_interruption(int code, struct pt_regs *regs)
 
 	if (code == 1)
 	    pdc_console_restart();  /* switch back to pdc if HPMC */
-	else
+	else if (!irqs_disabled_flags(regs->gr[0]))
 	    local_irq_enable();
 
 	/* Security check: