From mboxrd@z Thu Jan 1 00:00:00 1970 From: Geert Uytterhoeven Subject: [PATCH 4/5] m68k/amiga: Chip RAM - Change chipavail to an atomic_t Date: Sat, 21 May 2011 21:18:19 +0200 Message-ID: <1306005500-29259-4-git-send-email-geert@linux-m68k.org> References: <1306005500-29259-1-git-send-email-geert@linux-m68k.org> Return-path: In-Reply-To: <1306005500-29259-1-git-send-email-geert@linux-m68k.org> Sender: linux-m68k-owner@vger.kernel.org List-Id: linux-m68k@vger.kernel.org To: linux-m68k@lists.linux-m68k.org Cc: linux-kernel@vger.kernel.org, Geert Uytterhoeven While the core resource handling code is safe, our global counter must still be protected against concurrent modifications. Signed-off-by: Geert Uytterhoeven --- 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 #include +#include #include #include @@ -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