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Subject[PATCH 4/5] m68k/amiga: Chip RAM - Change chipavail to an atomic_t
Date
While the core resource handling code is safe, our global counter must
still be protected against concurrent modifications.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
---
arch/m68k/amiga/chipram.c | 15 +++++++++------
1 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/arch/m68k/amiga/chipram.c b/arch/m68k/amiga/chipram.c
index e5a8dbc..c3fe451 100644
--- a/arch/m68k/amiga/chipram.c
+++ b/arch/m68k/amiga/chipram.c
@@ -16,6 +16,7 @@
#include <linux/string.h>
#include <linux/module.h>

+#include <asm/atomic.h>
#include <asm/page.h>
#include <asm/amigahw.h>

@@ -25,7 +26,7 @@ EXPORT_SYMBOL(amiga_chip_size);
static struct resource chipram_res = {
.name = "Chip RAM", .start = CHIP_PHYSADDR
};
-static unsigned long chipavail;
+static atomic_t chipavail;


void __init amiga_chip_init(void)
@@ -36,7 +37,7 @@ void __init amiga_chip_init(void)
chipram_res.end = amiga_chip_size-1;
request_resource(&iomem_resource, &chipram_res);

- chipavail = amiga_chip_size;
+ atomic_set(&chipavail, amiga_chip_size);
}


@@ -84,7 +85,7 @@ void *amiga_chip_alloc_res(unsigned long size, struct resource *res)
return NULL;
}

- chipavail -= size;
+ atomic_sub(size, &chipavail);
pr_debug("amiga_chip_alloc_res: returning %pR\n", res);
return (void *)ZTWO_VADDR(res->start);
}
@@ -101,7 +102,7 @@ void amiga_chip_free(void *ptr)
*p = res->sibling;
size = res->end-start;
pr_debug("amiga_chip_free: free %lu bytes at %p\n", size, ptr);
- chipavail += size;
+ atomic_add(size, &chipavail);
kfree(res);
return;
}
@@ -113,8 +114,10 @@ EXPORT_SYMBOL(amiga_chip_free);

unsigned long amiga_chip_avail(void)
{
- pr_debug("amiga_chip_avail : %lu bytes\n", chipavail);
- return chipavail;
+ unsigned long n = atomic_read(&chipavail);
+
+ pr_debug("amiga_chip_avail : %lu bytes\n", n);
+ return n;
}
EXPORT_SYMBOL(amiga_chip_avail);

--
1.7.0.4


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