I finished now to fixup the alpha port for 2.3.42 (the smp cpu map update
part is from Jay Estabrook).
I developed from scratch rw semaphores based on spinlocks. The overhead
seems quite load by looking the code and they are at least quite obviously
right ;). BTW, they are not architecture-dependent so other archs can cut
and past if necessary.
diff -urN ref/arch/alpha/kernel/alpha_ksyms.c alpha-compile/arch/alpha/kernel/alpha_ksyms.c
--- ref/arch/alpha/kernel/alpha_ksyms.c Fri Feb 4 04:04:42 2000
+++ alpha-compile/arch/alpha/kernel/alpha_ksyms.c Thu Feb 3 22:20:21 2000
@@ -164,7 +164,8 @@
EXPORT_SYMBOL(flush_tlb_range);
EXPORT_SYMBOL(smp_imb);
EXPORT_SYMBOL(cpu_data);
-EXPORT_SYMBOL(cpu_number_map);
+EXPORT_SYMBOL(__cpu_number_map);
+EXPORT_SYMBOL(__cpu_logical_map);
EXPORT_SYMBOL(global_bh_lock);
EXPORT_SYMBOL(global_bh_count);
EXPORT_SYMBOL(synchronize_bh);
diff -urN ref/arch/alpha/kernel/semaphore.c alpha-compile/arch/alpha/kernel/semaphore.c
--- ref/arch/alpha/kernel/semaphore.c Tue Sep 14 14:34:22 1999
+++ alpha-compile/arch/alpha/kernel/semaphore.c Fri Feb 4 03:52:14 2000
@@ -127,3 +127,39 @@
{
return waking_non_zero_trylock(sem);
}
+
+/* RW spinlock-based semaphores, 2000 Andrea Arcangeli <andrea@suse.de> */
+
+void down_read_failed(struct rw_semaphore * sem)
+{
+ struct task_struct *tsk = current;
+ DECLARE_WAITQUEUE(wait, tsk);
+
+ add_wait_queue_exclusive(&sem->wait, &wait);
+
+ do {
+ __set_task_state(tsk, TASK_UNINTERRUPTIBLE|TASK_EXCLUSIVE);
+ spin_unlock_irq(&sem->lock);
+ schedule();
+ spin_lock_irq(&sem->lock);
+ } while (sem->wr);
+
+ remove_wait_queue(&sem->wait, &wait);
+}
+
+void down_write_failed(struct rw_semaphore * sem)
+{
+ struct task_struct *tsk = current;
+ DECLARE_WAITQUEUE(wait, tsk);
+
+ add_wait_queue_exclusive(&sem->wait, &wait);
+
+ do {
+ __set_task_state(tsk, TASK_UNINTERRUPTIBLE|TASK_EXCLUSIVE);
+ spin_unlock_irq(&sem->lock);
+ schedule();
+ spin_lock_irq(&sem->lock);
+ } while (sem->rd || sem->wr);
+
+ remove_wait_queue(&sem->wait, &wait);
+}
diff -urN ref/arch/alpha/kernel/smp.c alpha-compile/arch/alpha/kernel/smp.c
--- ref/arch/alpha/kernel/smp.c Fri Feb 4 04:04:42 2000
+++ alpha-compile/arch/alpha/kernel/smp.c Thu Feb 3 22:20:21 2000
@@ -71,7 +71,7 @@
int smp_threads_ready; /* True once the per process idle is forked. */
cycles_t cacheflush_time;
-int cpu_number_map[NR_CPUS];
+int __cpu_number_map[NR_CPUS];
int __cpu_logical_map[NR_CPUS];
extern void calibrate_delay(void);
@@ -433,7 +433,7 @@
idle->processor = cpuid;
__cpu_logical_map[cpunum] = cpuid;
- cpu_number_map[cpuid] = cpunum;
+ __cpu_number_map[cpuid] = cpunum;
idle->has_cpu = 1; /* we schedule the first task manually */
del_from_runqueue(idle);
@@ -462,7 +462,7 @@
/* we must invalidate our stuff as we failed to boot the CPU */
__cpu_logical_map[cpunum] = -1;
- cpu_number_map[cpuid] = -1;
+ __cpu_number_map[cpuid] = -1;
/* the idle task is local to us so free it as we don't use it */
free_task_struct(idle);
@@ -536,11 +536,11 @@
unsigned long bogosum;
/* Take care of some initial bookkeeping. */
- memset(cpu_number_map, -1, sizeof(cpu_number_map));
+ memset(__cpu_number_map, -1, sizeof(__cpu_number_map));
memset(__cpu_logical_map, -1, sizeof(__cpu_logical_map));
memset(ipi_data, 0, sizeof(ipi_data));
- cpu_number_map[smp_boot_cpuid] = 0;
+ __cpu_number_map[smp_boot_cpuid] = 0;
__cpu_logical_map[0] = smp_boot_cpuid;
current->processor = smp_boot_cpuid;
diff -urN ref/include/asm-alpha/semaphore.h alpha-compile/include/asm-alpha/semaphore.h
--- ref/include/asm-alpha/semaphore.h Thu Feb 3 22:21:25 2000
+++ alpha-compile/include/asm-alpha/semaphore.h Fri Feb 4 04:00:34 2000
@@ -6,6 +6,7 @@
*
* (C) Copyright 1996 Linus Torvalds
* (C) Copyright 1996 Richard Henderson
+ * (C) Copyright 2000 Andrea Arcangeli
*/
#include <asm/current.h>
@@ -265,5 +266,96 @@
: "m"(sem->count), "r"(pv)
: "$24", "$28", "memory");
}
+
+/* RW spinlock-based semaphores, 2000 Andrea Arcangeli <andrea@suse.de> */
+
+struct rw_semaphore
+{
+ spinlock_t lock;
+ int rd, wr;
+ wait_queue_head_t wait;
+#if WAITQUEUE_DEBUG
+ long __magic;
+#endif
+};
+
+#define __RWSEM_INITIALIZER(name, rd, wr) \
+{ \
+ SPIN_LOCK_UNLOCKED, \
+ (rd), (wr), \
+ __WAIT_QUEUE_HEAD_INITIALIZER((name).wait) \
+ __SEM_DEBUG_INIT(name) \
+}
+
+#define __DECLARE_RWSEM_GENERIC(name, rd, wr) \
+ struct rw_semaphore name = __RWSEM_INITIALIZER(name, rd, wr)
+
+#define DECLARE_RWSEM(name) __DECLARE_RWSEM_GENERIC(name, 0, 0)
+#define DECLARE_RWSEM_READ_LOCKED(name) __DECLARE_RWSEM_GENERIC(name, 1, 0)
+#define DECLARE_RWSEM_WRITE_LOCKED(name) __DECLARE_RWSEM_GENERIC(name, 0, 1)
+
+extern inline void init_rwsem(struct rw_semaphore * sem)
+{
+ spin_lock_init(&sem->lock);
+ sem->rd = sem->wr = 0;
+ init_waitqueue_head(&sem->wait);
+#if WAITQUEUE_DEBUG
+ sem->__magic = (long)&sem->__magic;
+#endif
+}
+
+#ifndef CHECK_MAGIC
+#define CHECK_MAGIC(x)
+#endif
+
+extern void down_read_failed(struct rw_semaphore *);
+extern void down_write_failed(struct rw_semaphore *);
+
+extern inline void down_read(struct rw_semaphore * sem)
+{
+ CHECK_MAGIC(sem->__magic);
+
+ spin_lock_irq(&sem->lock);
+ if (sem->wr)
+ down_read_failed(sem);
+ sem->rd++;
+ spin_unlock_irq(&sem->lock);
+}
+
+extern inline void down_write(struct rw_semaphore * sem)
+{
+ CHECK_MAGIC(sem->__magic);
+
+ spin_lock(&sem->lock);
+ if (sem->rd || sem->wr)
+ down_write_failed(sem);
+ sem->wr = 1;
+ spin_unlock(&sem->lock);
+}
+
+#define up_read(sem) \
+do { \
+ unsigned long flags; \
+ \
+ CHECK_MAGIC((sem)->__magic); \
+ \
+ spin_lock_irqsave(&(sem)->lock, flags); \
+ if (!--(sem)->rd && waitqueue_active(&(sem)->wait)) \
+ wake_up(&(sem)->wait); \
+ spin_unlock_irqrestore(&(sem)->lock, flags); \
+} while (0)
+
+#define up_write(sem) \
+do { \
+ unsigned long flags; \
+ \
+ CHECK_MAGIC((sem)->__magic); \
+ \
+ spin_lock_irqsave(&(sem)->lock, flags); \
+ (sem)->wr = 0; \
+ if (waitqueue_active(&(sem)->wait)) \
+ wake_up(&(sem)->wait); \
+ spin_unlock_irqrestore(&(sem)->lock, flags); \
+} while(0)
#endif
diff -urN ref/include/asm-alpha/smp.h alpha-compile/include/asm-alpha/smp.h
--- ref/include/asm-alpha/smp.h Fri Feb 4 04:04:42 2000
+++ alpha-compile/include/asm-alpha/smp.h Thu Feb 3 22:21:25 2000
@@ -45,7 +45,8 @@
/* Map from cpu id to sequential logical cpu number. This will only
not be idempotent when cpus failed to come on-line. */
-extern int cpu_number_map[NR_CPUS];
+extern int __cpu_number_map[NR_CPUS];
+#define cpu_number_map(cpu) __cpu_number_map[cpu]
/* The reverse map from sequential logical cpu number to cpu id. */
extern int __cpu_logical_map[NR_CPUS];
diff -urN ref/include/asm-alpha/types.h alpha-compile/include/asm-alpha/types.h
--- ref/include/asm-alpha/types.h Mon Jan 18 02:27:22 1999
+++ alpha-compile/include/asm-alpha/types.h Thu Feb 3 21:45:59 2000
@@ -71,6 +71,10 @@
typedef unsigned long u64;
#define BITS_PER_LONG 64
+/* Dma addresses are 32-bits wide. */
+
+typedef u32 dma_addr_t;
+
#endif
#endif /* __KERNEL__ */
Andrea
-
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