32 lines
998 B
Diff
32 lines
998 B
Diff
diff --git a/drivers/hwmon/applesmc.c b/drivers/hwmon/applesmc.c
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--- a/drivers/hwmon/applesmc.c
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+++ b/drivers/hwmon/applesmc.c
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@@ -33,6 +33,7 @@
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#include <linux/workqueue.h>
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#include <linux/err.h>
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#include <linux/bits.h>
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+#include <asm/barrier.h>
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/* data port used by Apple SMC */
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#define APPLESMC_DATA_PORT 0x300
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@@ -372,7 +373,8 @@ static const struct applesmc_entry *applesmc_get_entry_by_index(int index)
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__be32 be;
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int ret = 0;
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- if (cache->valid)
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+ /* Pairs with smp_store_release() to ensure cache contents are visible */
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+ if (smp_load_acquire(&cache->valid))
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return cache;
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mutex_lock(&smcreg.mutex);
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@@ -391,7 +393,8 @@ static const struct applesmc_entry *applesmc_get_entry_by_index(int index)
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cache->len = info[0];
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memcpy(cache->type, &info[1], 4);
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cache->flags = info[5];
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- cache->valid = true;
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+ /* Pairs with smp_load_acquire() to commit cache contents before setting valid */
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+ smp_store_release(&cache->valid, true);
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out:
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mutex_unlock(&smcreg.mutex);
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