MN10300: Cache: Implement SMP global cache flushing

Implement SMP global cache flushing for MN10300.  This will be used by the AM34
which is SMP capable.

Signed-off-by: Akira Takeuchi <takeuchi.akr@jp.panasonic.com>
Signed-off-by: Kiyoshi Owada <owada.kiyoshi@jp.panasonic.com>
Signed-off-by: David Howells <dhowells@redhat.com>

1 files changed, 105 insertions, 0 deletions

diff --git a/arch/mn10300/mm/cache-smp.c b/arch/mn10300/mm/cache-smp.c
new file mode 100644
index 000000000000..4a6e9a4b5b27
--- /dev/null
+++ b/arch/mn10300/mm/cache-smp.c
@@ -0,0 +1,105 @@
+/* SMP global caching code
+ *
+ * Copyright (C) 2010 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+#include <linux/module.h>
+#include <linux/mm.h>
+#include <linux/mman.h>
+#include <linux/threads.h>
+#include <linux/interrupt.h>
+#include <asm/page.h>
+#include <asm/pgtable.h>
+#include <asm/processor.h>
+#include <asm/cacheflush.h>
+#include <asm/io.h>
+#include <asm/uaccess.h>
+#include <asm/smp.h>
+#include "cache-smp.h"
+
+DEFINE_SPINLOCK(smp_cache_lock);
+static unsigned long smp_cache_mask;
+static unsigned long smp_cache_start;
+static unsigned long smp_cache_end;
+static cpumask_t smp_cache_ipi_map;		/* Bitmask of cache IPI done CPUs */
+
+/**
+ * smp_cache_interrupt - Handle IPI request to flush caches.
+ *
+ * Handle a request delivered by IPI to flush the current CPU's
+ * caches.  The parameters are stored in smp_cache_*.
+ */
+void smp_cache_interrupt(void)
+{
+	unsigned long opr_mask = smp_cache_mask;
+
+	switch ((enum smp_dcache_ops)(opr_mask & SMP_DCACHE_OP_MASK)) {
+	case SMP_DCACHE_NOP:
+		break;
+	case SMP_DCACHE_INV:
+		mn10300_local_dcache_inv();
+		break;
+	case SMP_DCACHE_INV_RANGE:
+		mn10300_local_dcache_inv_range(smp_cache_start, smp_cache_end);
+		break;
+	case SMP_DCACHE_FLUSH:
+		mn10300_local_dcache_flush();
+		break;
+	case SMP_DCACHE_FLUSH_RANGE:
+		mn10300_local_dcache_flush_range(smp_cache_start,
+						 smp_cache_end);
+		break;
+	case SMP_DCACHE_FLUSH_INV:
+		mn10300_local_dcache_flush_inv();
+		break;
+	case SMP_DCACHE_FLUSH_INV_RANGE:
+		mn10300_local_dcache_flush_inv_range(smp_cache_start,
+						     smp_cache_end);
+		break;
+	}
+
+	switch ((enum smp_icache_ops)(opr_mask & SMP_ICACHE_OP_MASK)) {
+	case SMP_ICACHE_NOP:
+		break;
+	case SMP_ICACHE_INV:
+		mn10300_local_icache_inv();
+		break;
+	case SMP_ICACHE_INV_RANGE:
+		mn10300_local_icache_inv_range(smp_cache_start, smp_cache_end);
+		break;
+	}
+
+	cpu_clear(smp_processor_id(), smp_cache_ipi_map);
+}
+
+/**
+ * smp_cache_call - Issue an IPI to request the other CPUs flush caches
+ * @opr_mask: Cache operation flags
+ * @start: Start address of request
+ * @end: End address of request
+ *
+ * Send cache flush IPI to other CPUs.  This invokes smp_cache_interrupt()
+ * above on those other CPUs and then waits for them to finish.
+ *
+ * The caller must hold smp_cache_lock.
+ */
+void smp_cache_call(unsigned long opr_mask,
+		    unsigned long start, unsigned long end)
+{
+	smp_cache_mask = opr_mask;
+	smp_cache_start = start;
+	smp_cache_end = end;
+	smp_cache_ipi_map = cpu_online_map;
+	cpu_clear(smp_processor_id(), smp_cache_ipi_map);
+
+	send_IPI_allbutself(FLUSH_CACHE_IPI);
+
+	while (!cpus_empty(smp_cache_ipi_map))
+		/* nothing. lockup detection does not belong here */
+		mb();
+}