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[PATCH][2.5][5/14] smp_call_function_on_cpu - MIPS64

To: Linux Kernel <linux-kernel@vger.kernel.org>
Subject: [PATCH][2.5][5/14] smp_call_function_on_cpu - MIPS64
From: Zwane Mwaikambo <zwane@zwane.ca>
Date: Fri, 14 Feb 2003 04:35:26 -0500 (EST)
Cc: Linus Torvalds <torvalds@transmeta.com>, "" <linux-mips@linux-mips.org>
Original-recipient: rfc822;linux-mips@linux-mips.org
Sender: linux-mips-bounce@linux-mips.org
 smp.c |   51 ++++++++++++++++++++++++++++++++++++++++-----------
 1 files changed, 40 insertions(+), 11 deletions(-)

Index: linux-2.5.60/arch/mips64/kernel/smp.c
===================================================================
RCS file: /build/cvsroot/linux-2.5.60/arch/mips64/kernel/smp.c,v
retrieving revision 1.1.1.1
diff -u -r1.1.1.1 smp.c
--- linux-2.5.60/arch/mips64/kernel/smp.c       10 Feb 2003 22:15:44 -0000      
1.1.1.1
+++ linux-2.5.60/arch/mips64/kernel/smp.c       14 Feb 2003 06:11:21 -0000
@@ -131,16 +131,35 @@
        int wait;
 } *call_data;
 
-int smp_call_function (void (*func) (void *info), void *info, int retry, 
-                                                               int wait)
+/*
+ * smp_call_function_on_cpu - Runs func on all processors in the mask
+ *
+ * @func: The function to run. This must be fast and non-blocking.
+ * @info: An arbitrary pointer to pass to the function.
+ * @wait: If true, wait (atomically) until function has completed on other 
CPUs.
+ * @mask The bitmask of CPUs to call the function
+ * 
+ * Returns 0 on success, else a negative status code. Does not return until
+ * remote CPUs are nearly ready to execute func or have executed it.
+ *
+ * You must not call this function with disabled interrupts or from a
+ * hardware interrupt handler or from a bottom half handler.
+ */
+
+int smp_call_function_on_cpu (void (*func) (void *info), void *info,
+                               int wait, unsigned long mask)
 {
        struct call_data_struct data;
-       int i, cpus = smp_num_cpus-1;
+       int i, cpu, num_cpus;
        static spinlock_t lock = SPIN_LOCK_UNLOCKED;
 
-       if (cpus == 0)
-               return 0;
-
+       cpu = get_cpu();
+       mask &= ~(1UL << cpu);
+       num_cpus = hweight64(mask);
+       if (num_cpus == 0) {
+               put_cpu_no_resched();   
+               return -EINVAL;
+       }
        data.func = func;
        data.info = info;
        atomic_set(&data.started, 0);
@@ -151,20 +170,30 @@
        spin_lock_bh(&lock);
        call_data = &data;
        /* Send a message to all other CPUs and wait for them to respond */
-       for (i = 0; i < smp_num_cpus; i++)
-               if (smp_processor_id() != i)
+       for (i = 0; i < NR_CPUS; i++) {
+               if (!cpu_online(i))
+                       continue;
+
+               if ((1UL << i) & mask)
                        sendintr(i, DOCALL);
+       }
 
        /* Wait for response */
-       /* FIXME: lock-up detection, backtrace on lock-up */
-       while (atomic_read(&data.started) != cpus)
+       while (atomic_read(&data.started) != num_cpus)
                barrier();
 
        if (wait)
-               while (atomic_read(&data.finished) != cpus)
+               while (atomic_read(&data.finished) != num_cpus)
                        barrier();
        spin_unlock_bh(&lock);
+       put_cpu_no_resched();
        return 0;
+}
+
+int smp_call_function (void (*func) (void *info), void *info, int retry, 
+                                                               int wait)
+{
+       return smp_call_function_on_cpu(func, info, wait, cpu_online_map);
 }
 
 extern void smp_call_function_interrupt(int irq, void *d, struct pt_regs *r)

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