Merge branch 'parisc-5.7-1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux

Pull parisc updates from Helge Deller:
 "Some cleanups in arch_rw locking functions, improved interrupt
  handling in arch spinlocks, coversions to request_irq() and syscall
  table generation cleanups"

* 'parisc-5.7-1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: remove nargs from __SYSCALL
  parisc: Refactor alternative code to accept multiple conditions
  parisc: Rework arch_rw locking functions
  parisc: Improve interrupt handling in arch_spin_lock_flags()
  parisc: Replace setup_irq() by request_irq()

arch/parisc/include/asm/spinlock.h

@@ -10,25 +10,34 @@
 static inline int arch_spin_is_locked(arch_spinlock_t *x)
 {
 	volatile unsigned int *a = __ldcw_align(x);
+	smp_mb();
 	return *a == 0;
 }
 
-#define arch_spin_lock(lock) arch_spin_lock_flags(lock, 0)
+static inline void arch_spin_lock(arch_spinlock_t *x)
+{
+	volatile unsigned int *a;
+
+	a = __ldcw_align(x);
+	while (__ldcw(a) == 0)
+		while (*a == 0)
+			cpu_relax();
+}
 
 static inline void arch_spin_lock_flags(arch_spinlock_t *x,
 					 unsigned long flags)
 {
 	volatile unsigned int *a;
+	unsigned long flags_dis;
 
 	a = __ldcw_align(x);
-	while (__ldcw(a) == 0)
+	while (__ldcw(a) == 0) {
+		local_save_flags(flags_dis);
+		local_irq_restore(flags);
 		while (*a == 0)
-			if (flags & PSW_SM_I) {
-				local_irq_enable();
-				cpu_relax();
-				local_irq_disable();
-			} else
-				cpu_relax();
+			cpu_relax();
+		local_irq_restore(flags_dis);
+	}
 }
 #define arch_spin_lock_flags arch_spin_lock_flags
 
@@ -58,116 +67,93 @@ static inline int arch_spin_trylock(arch_spinlock_t *x)
 
 /*
  * Read-write spinlocks, allowing multiple readers but only one writer.
- * Linux rwlocks are unfair to writers; they can be starved for an indefinite
- * time by readers.  With care, they can also be taken in interrupt context.
+ * Unfair locking as Writers could be starved indefinitely by Reader(s)
  *
- * In the PA-RISC implementation, we have a spinlock and a counter.
- * Readers use the lock to serialise their access to the counter (which
- * records how many readers currently hold the lock).
- * Writers hold the spinlock, preventing any readers or other writers from
- * grabbing the rwlock.
+ * The spinlock itself is contained in @counter and access to it is
+ * serialized with @lock_mutex.
  */
 
-/* Note that we have to ensure interrupts are disabled in case we're
- * interrupted by some other code that wants to grab the same read lock */
-static  __inline__ void arch_read_lock(arch_rwlock_t *rw)
+/* 1 - lock taken successfully */
+static inline int arch_read_trylock(arch_rwlock_t *rw)
 {
+	int ret = 0;
 	unsigned long flags;
-	local_irq_save(flags);
-	arch_spin_lock_flags(&rw->lock, flags);
-	rw->counter++;
-	arch_spin_unlock(&rw->lock);
-	local_irq_restore(flags);
-}
 
-/* Note that we have to ensure interrupts are disabled in case we're
- * interrupted by some other code that wants to grab the same read lock */
-static  __inline__ void arch_read_unlock(arch_rwlock_t *rw)
-{
-	unsigned long flags;
 	local_irq_save(flags);
-	arch_spin_lock_flags(&rw->lock, flags);
-	rw->counter--;
-	arch_spin_unlock(&rw->lock);
+	arch_spin_lock(&(rw->lock_mutex));
+
+	/*
+	 * zero means writer holds the lock exclusively, deny Reader.
+	 * Otherwise grant lock to first/subseq reader
+	 */
+	if (rw->counter > 0) {
+		rw->counter--;
+		ret = 1;
+	}
+
+	arch_spin_unlock(&(rw->lock_mutex));
 	local_irq_restore(flags);
+
+	return ret;
 }
 
-/* Note that we have to ensure interrupts are disabled in case we're
- * interrupted by some other code that wants to grab the same read lock */
-static __inline__ int arch_read_trylock(arch_rwlock_t *rw)
+/* 1 - lock taken successfully */
+static inline int arch_write_trylock(arch_rwlock_t *rw)
 {
+	int ret = 0;
 	unsigned long flags;
- retry:
+
 	local_irq_save(flags);
-	if (arch_spin_trylock(&rw->lock)) {
-		rw->counter++;
-		arch_spin_unlock(&rw->lock);
-		local_irq_restore(flags);
-		return 1;
+	arch_spin_lock(&(rw->lock_mutex));
+
+	/*
+	 * If reader(s) hold lock (lock < __ARCH_RW_LOCK_UNLOCKED__),
+	 * deny writer. Otherwise if unlocked grant to writer
+	 * Hence the claim that Linux rwlocks are unfair to writers.
+	 * (can be starved for an indefinite time by readers).
+	 */
+	if (rw->counter == __ARCH_RW_LOCK_UNLOCKED__) {
+		rw->counter = 0;
+		ret = 1;
 	}
-
+	arch_spin_unlock(&(rw->lock_mutex));
 	local_irq_restore(flags);
-	/* If write-locked, we fail to acquire the lock */
-	if (rw->counter < 0)
-		return 0;
 
-	/* Wait until we have a realistic chance at the lock */
-	while (arch_spin_is_locked(&rw->lock) && rw->counter >= 0)
+	return ret;
+}
+
+static inline void arch_read_lock(arch_rwlock_t *rw)
+{
+	while (!arch_read_trylock(rw))
 		cpu_relax();
+}
 
-	goto retry;
+static inline void arch_write_lock(arch_rwlock_t *rw)
+{
+	while (!arch_write_trylock(rw))
+		cpu_relax();
 }
 
-/* Note that we have to ensure interrupts are disabled in case we're
- * interrupted by some other code that wants to read_trylock() this lock */
-static __inline__ void arch_write_lock(arch_rwlock_t *rw)
+static inline void arch_read_unlock(arch_rwlock_t *rw)
 {
 	unsigned long flags;
-retry:
-	local_irq_save(flags);
-	arch_spin_lock_flags(&rw->lock, flags);
 
-	if (rw->counter != 0) {
-		arch_spin_unlock(&rw->lock);
-		local_irq_restore(flags);
-
-		while (rw->counter != 0)
-			cpu_relax();
-
-		goto retry;
-	}
-
-	rw->counter = -1; /* mark as write-locked */
-	mb();
+	local_irq_save(flags);
+	arch_spin_lock(&(rw->lock_mutex));
+	rw->counter++;
+	arch_spin_unlock(&(rw->lock_mutex));
 	local_irq_restore(flags);
 }
 
-static __inline__ void arch_write_unlock(arch_rwlock_t *rw)
-{
-	rw->counter = 0;
-	arch_spin_unlock(&rw->lock);
-}
-
-/* Note that we have to ensure interrupts are disabled in case we're
- * interrupted by some other code that wants to read_trylock() this lock */
-static __inline__ int arch_write_trylock(arch_rwlock_t *rw)
+static inline void arch_write_unlock(arch_rwlock_t *rw)
 {
 	unsigned long flags;
-	int result = 0;
 
 	local_irq_save(flags);
-	if (arch_spin_trylock(&rw->lock)) {
-		if (rw->counter == 0) {
-			rw->counter = -1;
-			result = 1;
-		} else {
-			/* Read-locked.  Oh well. */
-			arch_spin_unlock(&rw->lock);
-		}
-	}
+	arch_spin_lock(&(rw->lock_mutex));
+	rw->counter = __ARCH_RW_LOCK_UNLOCKED__;
+	arch_spin_unlock(&(rw->lock_mutex));
 	local_irq_restore(flags);
-
-	return result;
 }
 
 #endif /* __ASM_SPINLOCK_H */

arch/parisc/include/asm/spinlock_types.h

@@ -12,11 +12,19 @@ typedef struct {
 #endif
 } arch_spinlock_t;
 
+
+/* counter:
+ * Unlocked     : 0x0100_0000
+ * Read lock(s) : 0x00FF_FFFF to 0x01  (Multiple Readers decrement it)
+ * Write lock   : 0x0, but only if prior value is "unlocked" 0x0100_0000
+ */
 typedef struct {
-	arch_spinlock_t lock;
-	volatile int counter;
+	arch_spinlock_t		lock_mutex;
+	volatile unsigned int	counter;
 } arch_rwlock_t;
 
-#define __ARCH_RW_LOCK_UNLOCKED		{ __ARCH_SPIN_LOCK_UNLOCKED, 0 }
+#define __ARCH_RW_LOCK_UNLOCKED__       0x01000000
+#define __ARCH_RW_LOCK_UNLOCKED         { .lock_mutex = __ARCH_SPIN_LOCK_UNLOCKED, \
+					.counter = __ARCH_RW_LOCK_UNLOCKED__ }
 
 #endif

arch/parisc/kernel/alternative.c

@@ -25,6 +25,22 @@ void __init_or_module apply_alternatives(struct alt_instr *start,
 	struct alt_instr *entry;
 	int index = 0, applied = 0;
 	int num_cpus = num_online_cpus();
+	u32 cond_check;
+
+	cond_check = ALT_COND_ALWAYS |
+		((num_cpus == 1) ? ALT_COND_NO_SMP : 0) |
+		((cache_info.dc_size == 0) ? ALT_COND_NO_DCACHE : 0) |
+		((cache_info.ic_size == 0) ? ALT_COND_NO_ICACHE : 0) |
+		(running_on_qemu ? ALT_COND_RUN_ON_QEMU : 0) |
+		((split_tlb == 0) ? ALT_COND_NO_SPLIT_TLB : 0) |
+		/*
+		 * If the PDC_MODEL capabilities has Non-coherent IO-PDIR bit
+		 * set (bit #61, big endian), we have to flush and sync every
+		 * time IO-PDIR is changed in Ike/Astro.
+		 */
+		(((boot_cpu_data.cpu_type > pcxw_) &&
+		  ((boot_cpu_data.pdc.capabilities & PDC_MODEL_IOPDIR_FDC) == 0))
+			? ALT_COND_NO_IOC_FDC : 0);
 
 	for (entry = start; entry < end; entry++, index++) {
 
@@ -38,29 +54,14 @@ void __init_or_module apply_alternatives(struct alt_instr *start,
 
 		WARN_ON(!cond);
 
-		if (cond != ALT_COND_ALWAYS && no_alternatives)
+		if ((cond & ALT_COND_ALWAYS) == 0 && no_alternatives)
 			continue;
 
 		pr_debug("Check %d: Cond 0x%x, Replace %02d instructions @ 0x%px with 0x%08x\n",
 			index, cond, len, from, replacement);
 
-		if ((cond & ALT_COND_NO_SMP) && (num_cpus != 1))
-			continue;
-		if ((cond & ALT_COND_NO_DCACHE) && (cache_info.dc_size != 0))
-			continue;
-		if ((cond & ALT_COND_NO_ICACHE) && (cache_info.ic_size != 0))
-			continue;
-		if ((cond & ALT_COND_RUN_ON_QEMU) && !running_on_qemu)
-			continue;
-
-		/*
-		 * If the PDC_MODEL capabilities has Non-coherent IO-PDIR bit
-		 * set (bit #61, big endian), we have to flush and sync every
-		 * time IO-PDIR is changed in Ike/Astro.
-		 */
-		if ((cond & ALT_COND_NO_IOC_FDC) &&
-			((boot_cpu_data.cpu_type <= pcxw_) ||
-			 (boot_cpu_data.pdc.capabilities & PDC_MODEL_IOPDIR_FDC)))
+		/* Bounce out if none of the conditions are true. */
+		if ((cond & cond_check) == 0)
 			continue;
 
 		/* Want to replace pdtlb by a pdtlb,l instruction? */

arch/parisc/kernel/irq.c

@@ -560,33 +560,23 @@ void do_cpu_irq_mask(struct pt_regs *regs)
 	goto out;
 }
 
-static struct irqaction timer_action = {
-	.handler = timer_interrupt,
-	.name = "timer",
-	.flags = IRQF_TIMER | IRQF_PERCPU | IRQF_IRQPOLL,
-};
-
-#ifdef CONFIG_SMP
-static struct irqaction ipi_action = {
-	.handler = ipi_interrupt,
-	.name = "IPI",
-	.flags = IRQF_PERCPU,
-};
-#endif
-
 static void claim_cpu_irqs(void)
 {
+	unsigned long flags = IRQF_TIMER | IRQF_PERCPU | IRQF_IRQPOLL;
 	int i;
+
 	for (i = CPU_IRQ_BASE; i <= CPU_IRQ_MAX; i++) {
 		irq_set_chip_and_handler(i, &cpu_interrupt_type,
 					 handle_percpu_irq);
 	}
 
 	irq_set_handler(TIMER_IRQ, handle_percpu_irq);
-	setup_irq(TIMER_IRQ, &timer_action);
+	if (request_irq(TIMER_IRQ, timer_interrupt, flags, "timer", NULL))
+		pr_err("Failed to register timer interrupt\n");
 #ifdef CONFIG_SMP
 	irq_set_handler(IPI_IRQ, handle_percpu_irq);
-	setup_irq(IPI_IRQ, &ipi_action);
+	if (request_irq(IPI_IRQ, ipi_interrupt, IRQF_PERCPU, "IPI", NULL))
+		pr_err("Failed to register IPI interrupt\n");
 #endif
 }
 

arch/parisc/kernel/syscall.S

@@ -935,7 +935,7 @@ ENTRY(lws_table)
 END(lws_table)
 	/* End of lws table */
 
-#define __SYSCALL(nr, entry, nargs) ASM_ULONG_INSN entry
+#define __SYSCALL(nr, entry)	ASM_ULONG_INSN entry
 	.align 8
 ENTRY(sys_call_table)
 	.export sys_call_table,data

arch/parisc/kernel/syscalls/syscalltbl.sh

@@ -13,10 +13,10 @@ emit() {
 	t_entry="$3"
 
 	while [ $t_nxt -lt $t_nr ]; do
-		printf "__SYSCALL(%s, sys_ni_syscall, )\n" "${t_nxt}"
+		printf "__SYSCALL(%s,sys_ni_syscall)\n" "${t_nxt}"
 		t_nxt=$((t_nxt+1))
 	done
-	printf "__SYSCALL(%s, %s, )\n" "${t_nxt}" "${t_entry}"
+	printf "__SYSCALL(%s,%s)\n" "${t_nxt}" "${t_entry}"
 }
 
 grep -E "^[0-9A-Fa-fXx]+[[:space:]]+${my_abis}" "$in" | sort -n | (

drivers/parisc/eisa.c

@@ -243,11 +243,6 @@ static irqreturn_t dummy_irq2_handler(int _, void *dev)
 	return IRQ_HANDLED;
 }
 
-static struct irqaction irq2_action = {
-	.handler = dummy_irq2_handler,
-	.name = "cascade",
-};
-
 static void init_eisa_pic(void)
 {
 	unsigned long flags;
@@ -335,7 +330,8 @@ static int __init eisa_probe(struct parisc_device *dev)
 	}
 
 	/* Reserve IRQ2 */
-	setup_irq(2, &irq2_action);
+	if (request_irq(2, dummy_irq2_handler, 0, "cascade", NULL))
+		pr_err("Failed to request irq 2 (cascade)\n");
 	for (i = 0; i < 16; i++) {
 		irq_set_chip_and_handler(i, &eisa_interrupt_type,
 					 handle_simple_irq);