[PATCH 25/50] ACPI, Add 64bit read/write support to atomicio on i386

From: Len Brown
Date: Tue Jan 17 2012 - 08:22:42 EST


From: Huang Ying <ying.huang@xxxxxxxxx>

There is no 64bit read/write support in ACPI atomicio because
readq/writeq is used to implement 64bit read/write, but readq/writeq
is not available on i386. This patch implement 64bit read/write
support in atomicio via two readl/writel.

Signed-off-by: Huang Ying <ying.huang@xxxxxxxxx>
Signed-off-by: Len Brown <len.brown@xxxxxxxxx>
---
drivers/acpi/atomicio.c | 36 ++++++++++++++++++++++++++++++------
1 files changed, 30 insertions(+), 6 deletions(-)

diff --git a/drivers/acpi/atomicio.c b/drivers/acpi/atomicio.c
index cfc0cc1..1016f18 100644
--- a/drivers/acpi/atomicio.c
+++ b/drivers/acpi/atomicio.c
@@ -260,6 +260,21 @@ int acpi_post_unmap_gar(struct acpi_generic_address *reg)
}
EXPORT_SYMBOL_GPL(acpi_post_unmap_gar);

+#ifdef readq
+static inline u64 read64(const volatile void __iomem *addr)
+{
+ return readq(addr);
+}
+#else
+static inline u64 read64(const volatile void __iomem *addr)
+{
+ u64 l, h;
+ l = readl(addr);
+ h = readl(addr+4);
+ return l | (h << 32);
+}
+#endif
+
/*
* Can be used in atomic (including NMI) or process context. RCU read
* lock can only be released after the IO memory area accessing.
@@ -280,11 +295,9 @@ static int acpi_atomic_read_mem(u64 paddr, u64 *val, u32 width)
case 32:
*val = readl(addr);
break;
-#ifdef readq
case 64:
- *val = readq(addr);
+ *val = read64(addr);
break;
-#endif
default:
return -EINVAL;
}
@@ -293,6 +306,19 @@ static int acpi_atomic_read_mem(u64 paddr, u64 *val, u32 width)
return 0;
}

+#ifdef writeq
+static inline void write64(u64 val, volatile void __iomem *addr)
+{
+ writeq(val, addr);
+}
+#else
+static inline void write64(u64 val, volatile void __iomem *addr)
+{
+ writel(val, addr);
+ writel(val>>32, addr+4);
+}
+#endif
+
static int acpi_atomic_write_mem(u64 paddr, u64 val, u32 width)
{
void __iomem *addr;
@@ -309,11 +335,9 @@ static int acpi_atomic_write_mem(u64 paddr, u64 val, u32 width)
case 32:
writel(val, addr);
break;
-#ifdef writeq
case 64:
- writeq(val, addr);
+ write64(val, addr);
break;
-#endif
default:
return -EINVAL;
}
--
1.7.9.rc1

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