iomap: constify ioreadX() iomem argument (as in generic implementation)

Patch series "iomap: Constify ioreadX() iomem argument", v3.

The ioread8/16/32() and others have inconsistent interface among the
architectures: some taking address as const, some not.

It seems there is nothing really stopping all of them to take pointer to
const.

This patch (of 4):

The ioreadX() and ioreadX_rep() helpers have inconsistent interface.  On
some architectures void *__iomem address argument is a pointer to const,
on some not.

Implementations of ioreadX() do not modify the memory under the address so
they can be converted to a "const" version for const-safety and
consistency among architectures.

[krzk@kernel.org: sh: clk: fix assignment from incompatible pointer type for ioreadX()]
  Link: http://lkml.kernel.org/r/20200723082017.24053-1-krzk@kernel.org
[akpm@linux-foundation.org: fix drivers/mailbox/bcm-pdc-mailbox.c]
  Link: http://lkml.kernel.org/r/202007132209.Rxmv4QyS%25lkp@intel.com

Suggested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Cc: Kalle Valo <kvalo@codeaurora.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Jon Mason <jdmason@kudzu.us>
Cc: Allen Hubbe <allenbh@gmail.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Link: http://lkml.kernel.org/r/20200709072837.5869-1-krzk@kernel.org
Link: http://lkml.kernel.org/r/20200709072837.5869-2-krzk@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 11 insertions, 11 deletions

diff --git a/arch/sh/kernel/iomap.c b/arch/sh/kernel/iomap.c
index ef9e2c97cbb7..0a0dff4e66de 100644
--- a/arch/sh/kernel/iomap.c
+++ b/arch/sh/kernel/iomap.c
@@ -8,31 +8,31 @@
 #include <linux/module.h>
 #include <linux/io.h>
 
-unsigned int ioread8(void __iomem *addr)
+unsigned int ioread8(const void __iomem *addr)
 {
 	return readb(addr);
 }
 EXPORT_SYMBOL(ioread8);
 
-unsigned int ioread16(void __iomem *addr)
+unsigned int ioread16(const void __iomem *addr)
 {
 	return readw(addr);
 }
 EXPORT_SYMBOL(ioread16);
 
-unsigned int ioread16be(void __iomem *addr)
+unsigned int ioread16be(const void __iomem *addr)
 {
 	return be16_to_cpu(__raw_readw(addr));
 }
 EXPORT_SYMBOL(ioread16be);
 
-unsigned int ioread32(void __iomem *addr)
+unsigned int ioread32(const void __iomem *addr)
 {
 	return readl(addr);
 }
 EXPORT_SYMBOL(ioread32);
 
-unsigned int ioread32be(void __iomem *addr)
+unsigned int ioread32be(const void __iomem *addr)
 {
 	return be32_to_cpu(__raw_readl(addr));
 }
@@ -74,7 +74,7 @@ EXPORT_SYMBOL(iowrite32be);
  * convert to CPU byte order. We write in "IO byte
  * order" (we also don't have IO barriers).
  */
-static inline void mmio_insb(void __iomem *addr, u8 *dst, int count)
+static inline void mmio_insb(const void __iomem *addr, u8 *dst, int count)
 {
 	while (--count >= 0) {
 		u8 data = __raw_readb(addr);
@@ -83,7 +83,7 @@ static inline void mmio_insb(void __iomem *addr, u8 *dst, int count)
 	}
 }
 
-static inline void mmio_insw(void __iomem *addr, u16 *dst, int count)
+static inline void mmio_insw(const void __iomem *addr, u16 *dst, int count)
 {
 	while (--count >= 0) {
 		u16 data = __raw_readw(addr);
@@ -92,7 +92,7 @@ static inline void mmio_insw(void __iomem *addr, u16 *dst, int count)
 	}
 }
 
-static inline void mmio_insl(void __iomem *addr, u32 *dst, int count)
+static inline void mmio_insl(const void __iomem *addr, u32 *dst, int count)
 {
 	while (--count >= 0) {
 		u32 data = __raw_readl(addr);
@@ -125,19 +125,19 @@ static inline void mmio_outsl(void __iomem *addr, const u32 *src, int count)
 	}
 }
 
-void ioread8_rep(void __iomem *addr, void *dst, unsigned long count)
+void ioread8_rep(const void __iomem *addr, void *dst, unsigned long count)
 {
 	mmio_insb(addr, dst, count);
 }
 EXPORT_SYMBOL(ioread8_rep);
 
-void ioread16_rep(void __iomem *addr, void *dst, unsigned long count)
+void ioread16_rep(const void __iomem *addr, void *dst, unsigned long count)
 {
 	mmio_insw(addr, dst, count);
 }
 EXPORT_SYMBOL(ioread16_rep);
 
-void ioread32_rep(void __iomem *addr, void *dst, unsigned long count)
+void ioread32_rep(const void __iomem *addr, void *dst, unsigned long count)
 {
 	mmio_insl(addr, dst, count);
 }