Re: [PATCH 1/1] edac x38: new MC driver module

Hitoshi Mitake
2008-11-30T08:16:25Z

On Sat, 29 Nov 2008 19:01:44 +0100
Sam Ravnborg <sam@ravnborg.org> wrote:

> I see both rationales and you combine them in your patch - OK.
>
> And the reason why you cannot just add this to
> include/linux/io.h is that not all architectures
> provide a readl()/writel() I assume.
>
Yes, I can't say all architectures provide readl/writel.
And there may be some architecture depended problems,
so I can't decide to add my readq/writeq as architecture independent ones.

> Feel free to add my Acked-by: to the patch.

Thanks, I added your Acked-by to new patch.

description of this patch
Adding implementation of readq/writeq to x86_32,
and adding config value to x86 architecture to determine existence of readq/writeq

Signed-off-by: Hitoshi Mitake <h.mitake@gmail.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
---
arch/x86/Kconfig | 2 ++
arch/x86/include/asm/io.h | 24 ++++++++++++++++++++++++
2 files changed, 26 insertions(+), 0 deletions(-)

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index ac22bb7..75408fe 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -34,6 +34,8 @@ config X86
select HAVE_ARCH_TRACEHOOK
select HAVE_GENERIC_DMA_COHERENT if X86_32
select HAVE_EFFICIENT_UNALIGNED_ACCESS
+ select HAVE_READQ
+ select HAVE_WRITEQ

config ARCH_DEFCONFIG
string
diff --git a/arch/x86/include/asm/io.h b/arch/x86/include/asm/io.h
index ac2abc8..ddc67aa 100644
--- a/arch/x86/include/asm/io.h
+++ b/arch/x86/include/asm/io.h
@@ -4,6 +4,7 @@
#define ARCH_HAS_IOREMAP_WC

#include <linux/compiler.h>
+#include <asm-generic/int-ll64.h>

#define build_mmio_read(name, size, type, reg, barrier) \
static inline type name(const volatile void __iomem *addr) \
@@ -57,6 +58,29 @@ build_mmio_write(__writeq, "q", unsigned long, "r", )
/* Let people know we have them */
#define readq readq
#define writeq writeq
+
+#else /* CONFIG_X86_32 from here */
+
+static inline __u64 readq(const volatile void __iomem *addr)
+{
+ const volatile u32 __iomem *p = addr;
+ u32 l, h;
+
+ l = readl(p);
+ h = readl(p+1);
+
+ return l + ((u64)h << 32);
+}
+
+static inline void writeq(__u64 val, volatile void __iomem *addr)
+{
+ writel(val, addr);
+ writel(val >> 32, addr+4);
+}
+
+#define readq readq
+#define writeq writeq
+
#endif

extern int iommu_bio_merge;
--
1.5.6.5