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* [RFT 00/13] iomap: Constify ioreadX() iomem argument
@ 2020-01-07 16:52 Krzysztof Kozlowski
  2020-01-07 16:52 ` [RFT 01/13] iomap: Constify ioreadX() iomem argument (as in generic implementation) Krzysztof Kozlowski
                   ` (15 more replies)
  0 siblings, 16 replies; 31+ messages in thread
From: Krzysztof Kozlowski @ 2020-01-07 16:52 UTC (permalink / raw)
  To: Richard Henderson, Ivan Kokshaysky, Matt Turner, Alexey Brodkin,
	Vineet Gupta, James E.J. Bottomley, Helge Deller,
	Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman,
	Yoshinori Sato, Rich Felker, Dave Airlie, David Airlie,
	Daniel Vetter, Ben Skeggs, Mauro Carvalho Chehab, Jiri Slaby,
	Nick Kossifidis, Luis Chamberlain, Kalle Valo, David S. Miller,
	Dave Jiang, Jon Mason, Allen Hubbe, Michael S. Tsirkin,
	Jason Wang, Arnd Bergmann, Andrew Morton, Thomas Gleixner,
	Geert Uytterhoeven, linux-alpha, linux-kernel, linux-snps-arc,
	linux-parisc, linuxppc-dev, linux-sh, dri-devel, nouveau,
	linux-media, linux-wireless, netdev, linux-ntb, virtualization,
	linux-arch
  Cc: Krzysztof Kozlowski

Hi,

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.

Patchset was really tested on all affected architectures.
Build testing is in progress - I hope auto-builders will point any issues.


Todo
====
Convert also string versions (ioread16_rep() etc) if this aproach looks OK.


Merging
=======
The first 5 patches - iomap, alpha, sh, parisc and powerpc - should probably go
via one tree, or even squashed into one.

All other can go separately after these get merged.

Best regards,
Krzysztof


Krzysztof Kozlowski (13):
  iomap: Constify ioreadX() iomem argument (as in generic
    implementation)
  alpha: Constify ioreadX() iomem argument (as in generic
    implementation)
  sh: Constify ioreadX() iomem argument (as in generic implementation)
  parisc: Constify ioreadX() iomem argument (as in generic
    implementation)
  powerpc: Constify ioreadX() iomem argument (as in generic
    implementation)
  arc: Constify ioreadX() iomem argument (as in generic implementation)
  drm/mgag200: Constify ioreadX() iomem argument (as in generic
    implementation)
  drm/nouveau: Constify ioreadX() iomem argument (as in generic
    implementation)
  media: fsl-viu: Constify ioreadX() iomem argument (as in generic
    implementation)
  net: wireless: ath5k: Constify ioreadX() iomem argument (as in generic
    implementation)
  net: wireless: rtl818x: Constify ioreadX() iomem argument (as in
    generic implementation)
  ntb: intel: Constify ioreadX() iomem argument (as in generic
    implementation)
  virtio: pci: Constify ioreadX() iomem argument (as in generic
    implementation)

 arch/alpha/include/asm/core_apecs.h                |  6 +--
 arch/alpha/include/asm/core_cia.h                  |  6 +--
 arch/alpha/include/asm/core_lca.h                  |  6 +--
 arch/alpha/include/asm/core_marvel.h               |  4 +-
 arch/alpha/include/asm/core_mcpcia.h               |  6 +--
 arch/alpha/include/asm/core_t2.h                   |  2 +-
 arch/alpha/include/asm/io.h                        | 12 +++---
 arch/alpha/include/asm/io_trivial.h                | 16 ++++----
 arch/alpha/include/asm/jensen.h                    |  2 +-
 arch/alpha/include/asm/machvec.h                   |  6 +--
 arch/alpha/kernel/core_marvel.c                    |  2 +-
 arch/alpha/kernel/io.c                             |  6 +--
 arch/arc/plat-axs10x/axs10x.c                      |  4 +-
 arch/parisc/include/asm/io.h                       |  4 +-
 arch/parisc/lib/iomap.c                            | 48 +++++++++++-----------
 arch/powerpc/kernel/iomap.c                        | 22 +++++-----
 arch/sh/kernel/iomap.c                             | 10 ++---
 drivers/gpu/drm/mgag200/mgag200_drv.h              |  4 +-
 drivers/gpu/drm/nouveau/nouveau_bo.c               |  2 +-
 drivers/media/platform/fsl-viu.c                   |  2 +-
 drivers/net/wireless/ath/ath5k/ahb.c               | 10 ++---
 .../net/wireless/realtek/rtl818x/rtl8180/rtl8180.h |  6 +--
 drivers/ntb/hw/intel/ntb_hw_gen1.c                 |  2 +-
 drivers/ntb/hw/intel/ntb_hw_gen3.h                 |  2 +-
 drivers/ntb/hw/intel/ntb_hw_intel.h                |  2 +-
 drivers/virtio/virtio_pci_modern.c                 |  6 +--
 include/asm-generic/iomap.h                        | 22 +++++-----
 include/linux/io-64-nonatomic-hi-lo.h              |  4 +-
 include/linux/io-64-nonatomic-lo-hi.h              |  4 +-
 lib/iomap.c                                        | 18 ++++----
 30 files changed, 123 insertions(+), 123 deletions(-)

-- 
2.7.4


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linux-snps-arc@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-snps-arc

^ permalink raw reply	[flat|nested] 31+ messages in thread

* [RFT 01/13] iomap: Constify ioreadX() iomem argument (as in generic implementation)
  2020-01-07 16:52 [RFT 00/13] iomap: Constify ioreadX() iomem argument Krzysztof Kozlowski
@ 2020-01-07 16:52 ` Krzysztof Kozlowski
  2020-01-07 16:52 ` [RFT 02/13] alpha: " Krzysztof Kozlowski
                   ` (14 subsequent siblings)
  15 siblings, 0 replies; 31+ messages in thread
From: Krzysztof Kozlowski @ 2020-01-07 16:52 UTC (permalink / raw)
  To: Richard Henderson, Ivan Kokshaysky, Matt Turner, Alexey Brodkin,
	Vineet Gupta, James E.J. Bottomley, Helge Deller,
	Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman,
	Yoshinori Sato, Rich Felker, Dave Airlie, David Airlie,
	Daniel Vetter, Ben Skeggs, Mauro Carvalho Chehab, Jiri Slaby,
	Nick Kossifidis, Luis Chamberlain, Kalle Valo, David S. Miller,
	Dave Jiang, Jon Mason, Allen Hubbe, Michael S. Tsirkin,
	Jason Wang, Arnd Bergmann, Andrew Morton, Thomas Gleixner,
	Geert Uytterhoeven, linux-alpha, linux-kernel, linux-snps-arc,
	linux-parisc, linuxppc-dev, linux-sh, dri-devel, nouveau,
	linux-media, linux-wireless, netdev, linux-ntb, virtualization,
	linux-arch
  Cc: Krzysztof Kozlowski

The ioreadX() 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.

Suggested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
---
 include/asm-generic/iomap.h           | 22 +++++++++++-----------
 include/linux/io-64-nonatomic-hi-lo.h |  4 ++--
 include/linux/io-64-nonatomic-lo-hi.h |  4 ++--
 lib/iomap.c                           | 18 +++++++++---------
 4 files changed, 24 insertions(+), 24 deletions(-)

diff --git a/include/asm-generic/iomap.h b/include/asm-generic/iomap.h
index 9d28a5e82f73..986e894bef49 100644
--- a/include/asm-generic/iomap.h
+++ b/include/asm-generic/iomap.h
@@ -26,14 +26,14 @@
  * in the low address range. Architectures for which this is not
  * true can't use this generic implementation.
  */
-extern unsigned int ioread8(void __iomem *);
-extern unsigned int ioread16(void __iomem *);
-extern unsigned int ioread16be(void __iomem *);
-extern unsigned int ioread32(void __iomem *);
-extern unsigned int ioread32be(void __iomem *);
+extern unsigned int ioread8(const void __iomem *);
+extern unsigned int ioread16(const void __iomem *);
+extern unsigned int ioread16be(const void __iomem *);
+extern unsigned int ioread32(const void __iomem *);
+extern unsigned int ioread32be(const void __iomem *);
 #ifdef CONFIG_64BIT
-extern u64 ioread64(void __iomem *);
-extern u64 ioread64be(void __iomem *);
+extern u64 ioread64(const void __iomem *);
+extern u64 ioread64be(const void __iomem *);
 #endif
 
 #ifdef readq
@@ -41,10 +41,10 @@ extern u64 ioread64be(void __iomem *);
 #define ioread64_hi_lo ioread64_hi_lo
 #define ioread64be_lo_hi ioread64be_lo_hi
 #define ioread64be_hi_lo ioread64be_hi_lo
-extern u64 ioread64_lo_hi(void __iomem *addr);
-extern u64 ioread64_hi_lo(void __iomem *addr);
-extern u64 ioread64be_lo_hi(void __iomem *addr);
-extern u64 ioread64be_hi_lo(void __iomem *addr);
+extern u64 ioread64_lo_hi(const void __iomem *addr);
+extern u64 ioread64_hi_lo(const void __iomem *addr);
+extern u64 ioread64be_lo_hi(const void __iomem *addr);
+extern u64 ioread64be_hi_lo(const void __iomem *addr);
 #endif
 
 extern void iowrite8(u8, void __iomem *);
diff --git a/include/linux/io-64-nonatomic-hi-lo.h b/include/linux/io-64-nonatomic-hi-lo.h
index ae21b72cce85..f32522bb3aa5 100644
--- a/include/linux/io-64-nonatomic-hi-lo.h
+++ b/include/linux/io-64-nonatomic-hi-lo.h
@@ -57,7 +57,7 @@ static inline void hi_lo_writeq_relaxed(__u64 val, volatile void __iomem *addr)
 
 #ifndef ioread64_hi_lo
 #define ioread64_hi_lo ioread64_hi_lo
-static inline u64 ioread64_hi_lo(void __iomem *addr)
+static inline u64 ioread64_hi_lo(const void __iomem *addr)
 {
 	u32 low, high;
 
@@ -79,7 +79,7 @@ static inline void iowrite64_hi_lo(u64 val, void __iomem *addr)
 
 #ifndef ioread64be_hi_lo
 #define ioread64be_hi_lo ioread64be_hi_lo
-static inline u64 ioread64be_hi_lo(void __iomem *addr)
+static inline u64 ioread64be_hi_lo(const void __iomem *addr)
 {
 	u32 low, high;
 
diff --git a/include/linux/io-64-nonatomic-lo-hi.h b/include/linux/io-64-nonatomic-lo-hi.h
index faaa842dbdb9..448a21435dba 100644
--- a/include/linux/io-64-nonatomic-lo-hi.h
+++ b/include/linux/io-64-nonatomic-lo-hi.h
@@ -57,7 +57,7 @@ static inline void lo_hi_writeq_relaxed(__u64 val, volatile void __iomem *addr)
 
 #ifndef ioread64_lo_hi
 #define ioread64_lo_hi ioread64_lo_hi
-static inline u64 ioread64_lo_hi(void __iomem *addr)
+static inline u64 ioread64_lo_hi(const void __iomem *addr)
 {
 	u32 low, high;
 
@@ -79,7 +79,7 @@ static inline void iowrite64_lo_hi(u64 val, void __iomem *addr)
 
 #ifndef ioread64be_lo_hi
 #define ioread64be_lo_hi ioread64be_lo_hi
-static inline u64 ioread64be_lo_hi(void __iomem *addr)
+static inline u64 ioread64be_lo_hi(const void __iomem *addr)
 {
 	u32 low, high;
 
diff --git a/lib/iomap.c b/lib/iomap.c
index e909ab71e995..3b10c0ab2cee 100644
--- a/lib/iomap.c
+++ b/lib/iomap.c
@@ -70,27 +70,27 @@ static void bad_io_access(unsigned long port, const char *access)
 #define mmio_read64be(addr) swab64(readq(addr))
 #endif
 
-unsigned int ioread8(void __iomem *addr)
+unsigned int ioread8(const void __iomem *addr)
 {
 	IO_COND(addr, return inb(port), return readb(addr));
 	return 0xff;
 }
-unsigned int ioread16(void __iomem *addr)
+unsigned int ioread16(const void __iomem *addr)
 {
 	IO_COND(addr, return inw(port), return readw(addr));
 	return 0xffff;
 }
-unsigned int ioread16be(void __iomem *addr)
+unsigned int ioread16be(const void __iomem *addr)
 {
 	IO_COND(addr, return pio_read16be(port), return mmio_read16be(addr));
 	return 0xffff;
 }
-unsigned int ioread32(void __iomem *addr)
+unsigned int ioread32(const void __iomem *addr)
 {
 	IO_COND(addr, return inl(port), return readl(addr));
 	return 0xffffffff;
 }
-unsigned int ioread32be(void __iomem *addr)
+unsigned int ioread32be(const void __iomem *addr)
 {
 	IO_COND(addr, return pio_read32be(port), return mmio_read32be(addr));
 	return 0xffffffff;
@@ -142,26 +142,26 @@ static u64 pio_read64be_hi_lo(unsigned long port)
 	return lo | (hi << 32);
 }
 
-u64 ioread64_lo_hi(void __iomem *addr)
+u64 ioread64_lo_hi(const void __iomem *addr)
 {
 	IO_COND(addr, return pio_read64_lo_hi(port), return readq(addr));
 	return 0xffffffffffffffffULL;
 }
 
-u64 ioread64_hi_lo(void __iomem *addr)
+u64 ioread64_hi_lo(const void __iomem *addr)
 {
 	IO_COND(addr, return pio_read64_hi_lo(port), return readq(addr));
 	return 0xffffffffffffffffULL;
 }
 
-u64 ioread64be_lo_hi(void __iomem *addr)
+u64 ioread64be_lo_hi(const void __iomem *addr)
 {
 	IO_COND(addr, return pio_read64be_lo_hi(port),
 		return mmio_read64be(addr));
 	return 0xffffffffffffffffULL;
 }
 
-u64 ioread64be_hi_lo(void __iomem *addr)
+u64 ioread64be_hi_lo(const void __iomem *addr)
 {
 	IO_COND(addr, return pio_read64be_hi_lo(port),
 		return mmio_read64be(addr));
-- 
2.7.4


_______________________________________________
linux-snps-arc mailing list
linux-snps-arc@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-snps-arc

^ permalink raw reply	[flat|nested] 31+ messages in thread

* [RFT 02/13] alpha: Constify ioreadX() iomem argument (as in generic implementation)
  2020-01-07 16:52 [RFT 00/13] iomap: Constify ioreadX() iomem argument Krzysztof Kozlowski
  2020-01-07 16:52 ` [RFT 01/13] iomap: Constify ioreadX() iomem argument (as in generic implementation) Krzysztof Kozlowski
@ 2020-01-07 16:52 ` " Krzysztof Kozlowski
  2020-01-08  8:10   ` Geert Uytterhoeven
  2020-01-07 16:53 ` [RFT 02/13] sh: " Krzysztof Kozlowski
                   ` (13 subsequent siblings)
  15 siblings, 1 reply; 31+ messages in thread
From: Krzysztof Kozlowski @ 2020-01-07 16:52 UTC (permalink / raw)
  To: Richard Henderson, Ivan Kokshaysky, Matt Turner, Alexey Brodkin,
	Vineet Gupta, James E.J. Bottomley, Helge Deller,
	Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman,
	Yoshinori Sato, Rich Felker, Dave Airlie, David Airlie,
	Daniel Vetter, Ben Skeggs, Mauro Carvalho Chehab, Jiri Slaby,
	Nick Kossifidis, Luis Chamberlain, Kalle Valo, David S. Miller,
	Dave Jiang, Jon Mason, Allen Hubbe, Michael S. Tsirkin,
	Jason Wang, Arnd Bergmann, Andrew Morton, Thomas Gleixner,
	Geert Uytterhoeven, linux-alpha, linux-kernel, linux-snps-arc,
	linux-parisc, linuxppc-dev, linux-sh, dri-devel, nouveau,
	linux-media, linux-wireless, netdev, linux-ntb, virtualization,
	linux-arch
  Cc: Krzysztof Kozlowski

The ioreadX() 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.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
---
 arch/alpha/include/asm/core_apecs.h  |  6 +++---
 arch/alpha/include/asm/core_cia.h    |  6 +++---
 arch/alpha/include/asm/core_lca.h    |  6 +++---
 arch/alpha/include/asm/core_marvel.h |  4 ++--
 arch/alpha/include/asm/core_mcpcia.h |  6 +++---
 arch/alpha/include/asm/core_t2.h     |  2 +-
 arch/alpha/include/asm/io.h          | 12 ++++++------
 arch/alpha/include/asm/io_trivial.h  | 16 ++++++++--------
 arch/alpha/include/asm/jensen.h      |  2 +-
 arch/alpha/include/asm/machvec.h     |  6 +++---
 arch/alpha/kernel/core_marvel.c      |  2 +-
 arch/alpha/kernel/io.c               |  6 +++---
 12 files changed, 37 insertions(+), 37 deletions(-)

diff --git a/arch/alpha/include/asm/core_apecs.h b/arch/alpha/include/asm/core_apecs.h
index 0a07055bc0fe..2d9726fc02ef 100644
--- a/arch/alpha/include/asm/core_apecs.h
+++ b/arch/alpha/include/asm/core_apecs.h
@@ -384,7 +384,7 @@ struct el_apecs_procdata
 		}						\
 	} while (0)
 
-__EXTERN_INLINE unsigned int apecs_ioread8(void __iomem *xaddr)
+__EXTERN_INLINE unsigned int apecs_ioread8(const void __iomem *xaddr)
 {
 	unsigned long addr = (unsigned long) xaddr;
 	unsigned long result, base_and_type;
@@ -420,7 +420,7 @@ __EXTERN_INLINE void apecs_iowrite8(u8 b, void __iomem *xaddr)
 	*(vuip) ((addr << 5) + base_and_type) = w;
 }
 
-__EXTERN_INLINE unsigned int apecs_ioread16(void __iomem *xaddr)
+__EXTERN_INLINE unsigned int apecs_ioread16(const void __iomem *xaddr)
 {
 	unsigned long addr = (unsigned long) xaddr;
 	unsigned long result, base_and_type;
@@ -456,7 +456,7 @@ __EXTERN_INLINE void apecs_iowrite16(u16 b, void __iomem *xaddr)
 	*(vuip) ((addr << 5) + base_and_type) = w;
 }
 
-__EXTERN_INLINE unsigned int apecs_ioread32(void __iomem *xaddr)
+__EXTERN_INLINE unsigned int apecs_ioread32(const void __iomem *xaddr)
 {
 	unsigned long addr = (unsigned long) xaddr;
 	if (addr < APECS_DENSE_MEM)
diff --git a/arch/alpha/include/asm/core_cia.h b/arch/alpha/include/asm/core_cia.h
index c706a7f2b061..cb22991f6761 100644
--- a/arch/alpha/include/asm/core_cia.h
+++ b/arch/alpha/include/asm/core_cia.h
@@ -342,7 +342,7 @@ struct el_CIA_sysdata_mcheck {
 #define vuip	volatile unsigned int __force *
 #define vulp	volatile unsigned long __force *
 
-__EXTERN_INLINE unsigned int cia_ioread8(void __iomem *xaddr)
+__EXTERN_INLINE unsigned int cia_ioread8(const void __iomem *xaddr)
 {
 	unsigned long addr = (unsigned long) xaddr;
 	unsigned long result, base_and_type;
@@ -374,7 +374,7 @@ __EXTERN_INLINE void cia_iowrite8(u8 b, void __iomem *xaddr)
 	*(vuip) ((addr << 5) + base_and_type) = w;
 }
 
-__EXTERN_INLINE unsigned int cia_ioread16(void __iomem *xaddr)
+__EXTERN_INLINE unsigned int cia_ioread16(const void __iomem *xaddr)
 {
 	unsigned long addr = (unsigned long) xaddr;
 	unsigned long result, base_and_type;
@@ -404,7 +404,7 @@ __EXTERN_INLINE void cia_iowrite16(u16 b, void __iomem *xaddr)
 	*(vuip) ((addr << 5) + base_and_type) = w;
 }
 
-__EXTERN_INLINE unsigned int cia_ioread32(void __iomem *xaddr)
+__EXTERN_INLINE unsigned int cia_ioread32(const void __iomem *xaddr)
 {
 	unsigned long addr = (unsigned long) xaddr;
 	if (addr < CIA_DENSE_MEM)
diff --git a/arch/alpha/include/asm/core_lca.h b/arch/alpha/include/asm/core_lca.h
index 84d5e5b84f4f..ec86314418cb 100644
--- a/arch/alpha/include/asm/core_lca.h
+++ b/arch/alpha/include/asm/core_lca.h
@@ -230,7 +230,7 @@ union el_lca {
 	} while (0)
 
 
-__EXTERN_INLINE unsigned int lca_ioread8(void __iomem *xaddr)
+__EXTERN_INLINE unsigned int lca_ioread8(const void __iomem *xaddr)
 {
 	unsigned long addr = (unsigned long) xaddr;
 	unsigned long result, base_and_type;
@@ -266,7 +266,7 @@ __EXTERN_INLINE void lca_iowrite8(u8 b, void __iomem *xaddr)
 	*(vuip) ((addr << 5) + base_and_type) = w;
 }
 
-__EXTERN_INLINE unsigned int lca_ioread16(void __iomem *xaddr)
+__EXTERN_INLINE unsigned int lca_ioread16(const void __iomem *xaddr)
 {
 	unsigned long addr = (unsigned long) xaddr;
 	unsigned long result, base_and_type;
@@ -302,7 +302,7 @@ __EXTERN_INLINE void lca_iowrite16(u16 b, void __iomem *xaddr)
 	*(vuip) ((addr << 5) + base_and_type) = w;
 }
 
-__EXTERN_INLINE unsigned int lca_ioread32(void __iomem *xaddr)
+__EXTERN_INLINE unsigned int lca_ioread32(const void __iomem *xaddr)
 {
 	unsigned long addr = (unsigned long) xaddr;
 	if (addr < LCA_DENSE_MEM)
diff --git a/arch/alpha/include/asm/core_marvel.h b/arch/alpha/include/asm/core_marvel.h
index cc6fd92d5fa9..b266e02e284b 100644
--- a/arch/alpha/include/asm/core_marvel.h
+++ b/arch/alpha/include/asm/core_marvel.h
@@ -332,10 +332,10 @@ struct io7 {
 #define vucp	volatile unsigned char __force *
 #define vusp	volatile unsigned short __force *
 
-extern unsigned int marvel_ioread8(void __iomem *);
+extern unsigned int marvel_ioread8(const void __iomem *);
 extern void marvel_iowrite8(u8 b, void __iomem *);
 
-__EXTERN_INLINE unsigned int marvel_ioread16(void __iomem *addr)
+__EXTERN_INLINE unsigned int marvel_ioread16(const void __iomem *addr)
 {
 	return __kernel_ldwu(*(vusp)addr);
 }
diff --git a/arch/alpha/include/asm/core_mcpcia.h b/arch/alpha/include/asm/core_mcpcia.h
index b30dc128210d..cb24d1bd6141 100644
--- a/arch/alpha/include/asm/core_mcpcia.h
+++ b/arch/alpha/include/asm/core_mcpcia.h
@@ -267,7 +267,7 @@ extern inline int __mcpcia_is_mmio(unsigned long addr)
 	return (addr & 0x80000000UL) == 0;
 }
 
-__EXTERN_INLINE unsigned int mcpcia_ioread8(void __iomem *xaddr)
+__EXTERN_INLINE unsigned int mcpcia_ioread8(const void __iomem *xaddr)
 {
 	unsigned long addr = (unsigned long)xaddr & MCPCIA_MEM_MASK;
 	unsigned long hose = (unsigned long)xaddr & ~MCPCIA_MEM_MASK;
@@ -291,7 +291,7 @@ __EXTERN_INLINE void mcpcia_iowrite8(u8 b, void __iomem *xaddr)
 	*(vuip) ((addr << 5) + hose + 0x00) = w;
 }
 
-__EXTERN_INLINE unsigned int mcpcia_ioread16(void __iomem *xaddr)
+__EXTERN_INLINE unsigned int mcpcia_ioread16(const void __iomem *xaddr)
 {
 	unsigned long addr = (unsigned long)xaddr & MCPCIA_MEM_MASK;
 	unsigned long hose = (unsigned long)xaddr & ~MCPCIA_MEM_MASK;
@@ -315,7 +315,7 @@ __EXTERN_INLINE void mcpcia_iowrite16(u16 b, void __iomem *xaddr)
 	*(vuip) ((addr << 5) + hose + 0x08) = w;
 }
 
-__EXTERN_INLINE unsigned int mcpcia_ioread32(void __iomem *xaddr)
+__EXTERN_INLINE unsigned int mcpcia_ioread32(const void __iomem *xaddr)
 {
 	unsigned long addr = (unsigned long)xaddr;
 
diff --git a/arch/alpha/include/asm/core_t2.h b/arch/alpha/include/asm/core_t2.h
index e0b33d09e93a..12bb7addc789 100644
--- a/arch/alpha/include/asm/core_t2.h
+++ b/arch/alpha/include/asm/core_t2.h
@@ -572,7 +572,7 @@ __EXTERN_INLINE int t2_is_mmio(const volatile void __iomem *addr)
    it doesn't make sense to merge the pio and mmio routines.  */
 
 #define IOPORT(OS, NS)							\
-__EXTERN_INLINE unsigned int t2_ioread##NS(void __iomem *xaddr)		\
+__EXTERN_INLINE unsigned int t2_ioread##NS(const void __iomem *xaddr)		\
 {									\
 	if (t2_is_mmio(xaddr))						\
 		return t2_read##OS(xaddr);				\
diff --git a/arch/alpha/include/asm/io.h b/arch/alpha/include/asm/io.h
index d1ed5a8133c5..cc12ec74175c 100644
--- a/arch/alpha/include/asm/io.h
+++ b/arch/alpha/include/asm/io.h
@@ -151,9 +151,9 @@ static inline void generic_##NAME(TYPE b, QUAL void __iomem *addr)	\
 	alpha_mv.mv_##NAME(b, addr);					\
 }
 
-REMAP1(unsigned int, ioread8, /**/)
-REMAP1(unsigned int, ioread16, /**/)
-REMAP1(unsigned int, ioread32, /**/)
+REMAP1(unsigned int, ioread8, const)
+REMAP1(unsigned int, ioread16, const)
+REMAP1(unsigned int, ioread32, const)
 REMAP1(u8, readb, const volatile)
 REMAP1(u16, readw, const volatile)
 REMAP1(u32, readl, const volatile)
@@ -308,14 +308,14 @@ static inline int __is_mmio(const volatile void __iomem *addr)
  */
 
 #if IO_CONCAT(__IO_PREFIX,trivial_io_bw)
-extern inline unsigned int ioread8(void __iomem *addr)
+extern inline unsigned int ioread8(const void __iomem *addr)
 {
 	unsigned int ret = IO_CONCAT(__IO_PREFIX,ioread8)(addr);
 	mb();
 	return ret;
 }
 
-extern inline unsigned int ioread16(void __iomem *addr)
+extern inline unsigned int ioread16(const void __iomem *addr)
 {
 	unsigned int ret = IO_CONCAT(__IO_PREFIX,ioread16)(addr);
 	mb();
@@ -356,7 +356,7 @@ extern inline void outw(u16 b, unsigned long port)
 #endif
 
 #if IO_CONCAT(__IO_PREFIX,trivial_io_lq)
-extern inline unsigned int ioread32(void __iomem *addr)
+extern inline unsigned int ioread32(const void __iomem *addr)
 {
 	unsigned int ret = IO_CONCAT(__IO_PREFIX,ioread32)(addr);
 	mb();
diff --git a/arch/alpha/include/asm/io_trivial.h b/arch/alpha/include/asm/io_trivial.h
index ba3d8f0cfe0c..a1a29cbe02fa 100644
--- a/arch/alpha/include/asm/io_trivial.h
+++ b/arch/alpha/include/asm/io_trivial.h
@@ -7,15 +7,15 @@
 
 #if IO_CONCAT(__IO_PREFIX,trivial_io_bw)
 __EXTERN_INLINE unsigned int
-IO_CONCAT(__IO_PREFIX,ioread8)(void __iomem *a)
+IO_CONCAT(__IO_PREFIX,ioread8)(const void __iomem *a)
 {
-	return __kernel_ldbu(*(volatile u8 __force *)a);
+	return __kernel_ldbu(*(const volatile u8 __force *)a);
 }
 
 __EXTERN_INLINE unsigned int
-IO_CONCAT(__IO_PREFIX,ioread16)(void __iomem *a)
+IO_CONCAT(__IO_PREFIX,ioread16)(const void __iomem *a)
 {
-	return __kernel_ldwu(*(volatile u16 __force *)a);
+	return __kernel_ldwu(*(const volatile u16 __force *)a);
 }
 
 __EXTERN_INLINE void
@@ -33,9 +33,9 @@ IO_CONCAT(__IO_PREFIX,iowrite16)(u16 b, void __iomem *a)
 
 #if IO_CONCAT(__IO_PREFIX,trivial_io_lq)
 __EXTERN_INLINE unsigned int
-IO_CONCAT(__IO_PREFIX,ioread32)(void __iomem *a)
+IO_CONCAT(__IO_PREFIX,ioread32)(const void __iomem *a)
 {
-	return *(volatile u32 __force *)a;
+	return *(const volatile u32 __force *)a;
 }
 
 __EXTERN_INLINE void
@@ -73,14 +73,14 @@ IO_CONCAT(__IO_PREFIX,writew)(u16 b, volatile void __iomem *a)
 __EXTERN_INLINE u8
 IO_CONCAT(__IO_PREFIX,readb)(const volatile void __iomem *a)
 {
-	void __iomem *addr = (void __iomem *)a;
+	const void __iomem *addr = (const void __iomem *)a;
 	return IO_CONCAT(__IO_PREFIX,ioread8)(addr);
 }
 
 __EXTERN_INLINE u16
 IO_CONCAT(__IO_PREFIX,readw)(const volatile void __iomem *a)
 {
-	void __iomem *addr = (void __iomem *)a;
+	const void __iomem *addr = (const void __iomem *)a;
 	return IO_CONCAT(__IO_PREFIX,ioread16)(addr);
 }
 
diff --git a/arch/alpha/include/asm/jensen.h b/arch/alpha/include/asm/jensen.h
index 436dc905b6ad..916895155a88 100644
--- a/arch/alpha/include/asm/jensen.h
+++ b/arch/alpha/include/asm/jensen.h
@@ -305,7 +305,7 @@ __EXTERN_INLINE int jensen_is_mmio(const volatile void __iomem *addr)
    that it doesn't make sense to merge them.  */
 
 #define IOPORT(OS, NS)							\
-__EXTERN_INLINE unsigned int jensen_ioread##NS(void __iomem *xaddr)	\
+__EXTERN_INLINE unsigned int jensen_ioread##NS(const void __iomem *xaddr)	\
 {									\
 	if (jensen_is_mmio(xaddr))					\
 		return jensen_read##OS(xaddr - 0x100000000ul);		\
diff --git a/arch/alpha/include/asm/machvec.h b/arch/alpha/include/asm/machvec.h
index a6b73c6d10ee..a4e96e2bec74 100644
--- a/arch/alpha/include/asm/machvec.h
+++ b/arch/alpha/include/asm/machvec.h
@@ -46,9 +46,9 @@ struct alpha_machine_vector
 	void (*mv_pci_tbi)(struct pci_controller *hose,
 			   dma_addr_t start, dma_addr_t end);
 
-	unsigned int (*mv_ioread8)(void __iomem *);
-	unsigned int (*mv_ioread16)(void __iomem *);
-	unsigned int (*mv_ioread32)(void __iomem *);
+	unsigned int (*mv_ioread8)(const void __iomem *);
+	unsigned int (*mv_ioread16)(const void __iomem *);
+	unsigned int (*mv_ioread32)(const void __iomem *);
 
 	void (*mv_iowrite8)(u8, void __iomem *);
 	void (*mv_iowrite16)(u16, void __iomem *);
diff --git a/arch/alpha/kernel/core_marvel.c b/arch/alpha/kernel/core_marvel.c
index 1db9d0eb2922..37514422f586 100644
--- a/arch/alpha/kernel/core_marvel.c
+++ b/arch/alpha/kernel/core_marvel.c
@@ -807,7 +807,7 @@ void __iomem *marvel_ioportmap (unsigned long addr)
 }
 
 unsigned int
-marvel_ioread8(void __iomem *xaddr)
+marvel_ioread8(const void __iomem *xaddr)
 {
 	unsigned long addr = (unsigned long) xaddr;
 	if (__marvel_is_port_kbd(addr))
diff --git a/arch/alpha/kernel/io.c b/arch/alpha/kernel/io.c
index c025a3e5e357..e49918b91fee 100644
--- a/arch/alpha/kernel/io.c
+++ b/arch/alpha/kernel/io.c
@@ -14,21 +14,21 @@
    "generic", which bumps through the machine vector.  */
 
 unsigned int
-ioread8(void __iomem *addr)
+ioread8(const void __iomem *addr)
 {
 	unsigned int ret = IO_CONCAT(__IO_PREFIX,ioread8)(addr);
 	mb();
 	return ret;
 }
 
-unsigned int ioread16(void __iomem *addr)
+unsigned int ioread16(const void __iomem *addr)
 {
 	unsigned int ret = IO_CONCAT(__IO_PREFIX,ioread16)(addr);
 	mb();
 	return ret;
 }
 
-unsigned int ioread32(void __iomem *addr)
+unsigned int ioread32(const void __iomem *addr)
 {
 	unsigned int ret = IO_CONCAT(__IO_PREFIX,ioread32)(addr);
 	mb();
-- 
2.7.4


_______________________________________________
linux-snps-arc mailing list
linux-snps-arc@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-snps-arc

^ permalink raw reply	[flat|nested] 31+ messages in thread

* [RFT 02/13] sh: Constify ioreadX() iomem argument (as in generic implementation)
  2020-01-07 16:52 [RFT 00/13] iomap: Constify ioreadX() iomem argument Krzysztof Kozlowski
  2020-01-07 16:52 ` [RFT 01/13] iomap: Constify ioreadX() iomem argument (as in generic implementation) Krzysztof Kozlowski
  2020-01-07 16:52 ` [RFT 02/13] alpha: " Krzysztof Kozlowski
@ 2020-01-07 16:53 ` " Krzysztof Kozlowski
  2020-01-07 16:53 ` [RFT 03/13] alpha: " Krzysztof Kozlowski
                   ` (12 subsequent siblings)
  15 siblings, 0 replies; 31+ messages in thread
From: Krzysztof Kozlowski @ 2020-01-07 16:53 UTC (permalink / raw)
  To: Richard Henderson, Ivan Kokshaysky, Matt Turner, Alexey Brodkin,
	Vineet Gupta, James E.J. Bottomley, Helge Deller,
	Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman,
	Yoshinori Sato, Rich Felker, Dave Airlie, David Airlie,
	Daniel Vetter, Ben Skeggs, Mauro Carvalho Chehab, Jiri Slaby,
	Nick Kossifidis, Luis Chamberlain, Kalle Valo, David S. Miller,
	Dave Jiang, Jon Mason, Allen Hubbe, Michael S. Tsirkin,
	Jason Wang, Arnd Bergmann, Andrew Morton, Thomas Gleixner,
	Geert Uytterhoeven, linux-alpha, linux-kernel, linux-snps-arc,
	linux-parisc, linuxppc-dev, linux-sh, dri-devel, nouveau,
	linux-media, linux-wireless, netdev, linux-ntb, virtualization,
	linux-arch
  Cc: Krzysztof Kozlowski

The ioreadX() 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.

Suggested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
---
 arch/sh/kernel/iomap.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/arch/sh/kernel/iomap.c b/arch/sh/kernel/iomap.c
index ef9e2c97cbb7..bd5e212c6ea6 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));
 }
-- 
2.7.4


_______________________________________________
linux-snps-arc mailing list
linux-snps-arc@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-snps-arc

^ permalink raw reply	[flat|nested] 31+ messages in thread

* [RFT 03/13] alpha: Constify ioreadX() iomem argument (as in generic implementation)
  2020-01-07 16:52 [RFT 00/13] iomap: Constify ioreadX() iomem argument Krzysztof Kozlowski
                   ` (2 preceding siblings ...)
  2020-01-07 16:53 ` [RFT 02/13] sh: " Krzysztof Kozlowski
@ 2020-01-07 16:53 ` " Krzysztof Kozlowski
  2020-01-07 16:53 ` [RFT 03/13] sh: " Krzysztof Kozlowski
                   ` (11 subsequent siblings)
  15 siblings, 0 replies; 31+ messages in thread
From: Krzysztof Kozlowski @ 2020-01-07 16:53 UTC (permalink / raw)
  To: Richard Henderson, Ivan Kokshaysky, Matt Turner, Alexey Brodkin,
	Vineet Gupta, James E.J. Bottomley, Helge Deller,
	Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman,
	Yoshinori Sato, Rich Felker, Dave Airlie, David Airlie,
	Daniel Vetter, Ben Skeggs, Mauro Carvalho Chehab, Jiri Slaby,
	Nick Kossifidis, Luis Chamberlain, Kalle Valo, David S. Miller,
	Dave Jiang, Jon Mason, Allen Hubbe, Michael S. Tsirkin,
	Jason Wang, Arnd Bergmann, Andrew Morton, Thomas Gleixner,
	Geert Uytterhoeven, linux-alpha, linux-kernel, linux-snps-arc,
	linux-parisc, linuxppc-dev, linux-sh, dri-devel, nouveau,
	linux-media, linux-wireless, netdev, linux-ntb, virtualization,
	linux-arch
  Cc: Krzysztof Kozlowski

The ioreadX() 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.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
---
 arch/alpha/include/asm/core_apecs.h  |  6 +++---
 arch/alpha/include/asm/core_cia.h    |  6 +++---
 arch/alpha/include/asm/core_lca.h    |  6 +++---
 arch/alpha/include/asm/core_marvel.h |  4 ++--
 arch/alpha/include/asm/core_mcpcia.h |  6 +++---
 arch/alpha/include/asm/core_t2.h     |  2 +-
 arch/alpha/include/asm/io.h          | 12 ++++++------
 arch/alpha/include/asm/io_trivial.h  | 16 ++++++++--------
 arch/alpha/include/asm/jensen.h      |  2 +-
 arch/alpha/include/asm/machvec.h     |  6 +++---
 arch/alpha/kernel/core_marvel.c      |  2 +-
 arch/alpha/kernel/io.c               |  6 +++---
 12 files changed, 37 insertions(+), 37 deletions(-)

diff --git a/arch/alpha/include/asm/core_apecs.h b/arch/alpha/include/asm/core_apecs.h
index 0a07055bc0fe..2d9726fc02ef 100644
--- a/arch/alpha/include/asm/core_apecs.h
+++ b/arch/alpha/include/asm/core_apecs.h
@@ -384,7 +384,7 @@ struct el_apecs_procdata
 		}						\
 	} while (0)
 
-__EXTERN_INLINE unsigned int apecs_ioread8(void __iomem *xaddr)
+__EXTERN_INLINE unsigned int apecs_ioread8(const void __iomem *xaddr)
 {
 	unsigned long addr = (unsigned long) xaddr;
 	unsigned long result, base_and_type;
@@ -420,7 +420,7 @@ __EXTERN_INLINE void apecs_iowrite8(u8 b, void __iomem *xaddr)
 	*(vuip) ((addr << 5) + base_and_type) = w;
 }
 
-__EXTERN_INLINE unsigned int apecs_ioread16(void __iomem *xaddr)
+__EXTERN_INLINE unsigned int apecs_ioread16(const void __iomem *xaddr)
 {
 	unsigned long addr = (unsigned long) xaddr;
 	unsigned long result, base_and_type;
@@ -456,7 +456,7 @@ __EXTERN_INLINE void apecs_iowrite16(u16 b, void __iomem *xaddr)
 	*(vuip) ((addr << 5) + base_and_type) = w;
 }
 
-__EXTERN_INLINE unsigned int apecs_ioread32(void __iomem *xaddr)
+__EXTERN_INLINE unsigned int apecs_ioread32(const void __iomem *xaddr)
 {
 	unsigned long addr = (unsigned long) xaddr;
 	if (addr < APECS_DENSE_MEM)
diff --git a/arch/alpha/include/asm/core_cia.h b/arch/alpha/include/asm/core_cia.h
index c706a7f2b061..cb22991f6761 100644
--- a/arch/alpha/include/asm/core_cia.h
+++ b/arch/alpha/include/asm/core_cia.h
@@ -342,7 +342,7 @@ struct el_CIA_sysdata_mcheck {
 #define vuip	volatile unsigned int __force *
 #define vulp	volatile unsigned long __force *
 
-__EXTERN_INLINE unsigned int cia_ioread8(void __iomem *xaddr)
+__EXTERN_INLINE unsigned int cia_ioread8(const void __iomem *xaddr)
 {
 	unsigned long addr = (unsigned long) xaddr;
 	unsigned long result, base_and_type;
@@ -374,7 +374,7 @@ __EXTERN_INLINE void cia_iowrite8(u8 b, void __iomem *xaddr)
 	*(vuip) ((addr << 5) + base_and_type) = w;
 }
 
-__EXTERN_INLINE unsigned int cia_ioread16(void __iomem *xaddr)
+__EXTERN_INLINE unsigned int cia_ioread16(const void __iomem *xaddr)
 {
 	unsigned long addr = (unsigned long) xaddr;
 	unsigned long result, base_and_type;
@@ -404,7 +404,7 @@ __EXTERN_INLINE void cia_iowrite16(u16 b, void __iomem *xaddr)
 	*(vuip) ((addr << 5) + base_and_type) = w;
 }
 
-__EXTERN_INLINE unsigned int cia_ioread32(void __iomem *xaddr)
+__EXTERN_INLINE unsigned int cia_ioread32(const void __iomem *xaddr)
 {
 	unsigned long addr = (unsigned long) xaddr;
 	if (addr < CIA_DENSE_MEM)
diff --git a/arch/alpha/include/asm/core_lca.h b/arch/alpha/include/asm/core_lca.h
index 84d5e5b84f4f..ec86314418cb 100644
--- a/arch/alpha/include/asm/core_lca.h
+++ b/arch/alpha/include/asm/core_lca.h
@@ -230,7 +230,7 @@ union el_lca {
 	} while (0)
 
 
-__EXTERN_INLINE unsigned int lca_ioread8(void __iomem *xaddr)
+__EXTERN_INLINE unsigned int lca_ioread8(const void __iomem *xaddr)
 {
 	unsigned long addr = (unsigned long) xaddr;
 	unsigned long result, base_and_type;
@@ -266,7 +266,7 @@ __EXTERN_INLINE void lca_iowrite8(u8 b, void __iomem *xaddr)
 	*(vuip) ((addr << 5) + base_and_type) = w;
 }
 
-__EXTERN_INLINE unsigned int lca_ioread16(void __iomem *xaddr)
+__EXTERN_INLINE unsigned int lca_ioread16(const void __iomem *xaddr)
 {
 	unsigned long addr = (unsigned long) xaddr;
 	unsigned long result, base_and_type;
@@ -302,7 +302,7 @@ __EXTERN_INLINE void lca_iowrite16(u16 b, void __iomem *xaddr)
 	*(vuip) ((addr << 5) + base_and_type) = w;
 }
 
-__EXTERN_INLINE unsigned int lca_ioread32(void __iomem *xaddr)
+__EXTERN_INLINE unsigned int lca_ioread32(const void __iomem *xaddr)
 {
 	unsigned long addr = (unsigned long) xaddr;
 	if (addr < LCA_DENSE_MEM)
diff --git a/arch/alpha/include/asm/core_marvel.h b/arch/alpha/include/asm/core_marvel.h
index cc6fd92d5fa9..b266e02e284b 100644
--- a/arch/alpha/include/asm/core_marvel.h
+++ b/arch/alpha/include/asm/core_marvel.h
@@ -332,10 +332,10 @@ struct io7 {
 #define vucp	volatile unsigned char __force *
 #define vusp	volatile unsigned short __force *
 
-extern unsigned int marvel_ioread8(void __iomem *);
+extern unsigned int marvel_ioread8(const void __iomem *);
 extern void marvel_iowrite8(u8 b, void __iomem *);
 
-__EXTERN_INLINE unsigned int marvel_ioread16(void __iomem *addr)
+__EXTERN_INLINE unsigned int marvel_ioread16(const void __iomem *addr)
 {
 	return __kernel_ldwu(*(vusp)addr);
 }
diff --git a/arch/alpha/include/asm/core_mcpcia.h b/arch/alpha/include/asm/core_mcpcia.h
index b30dc128210d..cb24d1bd6141 100644
--- a/arch/alpha/include/asm/core_mcpcia.h
+++ b/arch/alpha/include/asm/core_mcpcia.h
@@ -267,7 +267,7 @@ extern inline int __mcpcia_is_mmio(unsigned long addr)
 	return (addr & 0x80000000UL) == 0;
 }
 
-__EXTERN_INLINE unsigned int mcpcia_ioread8(void __iomem *xaddr)
+__EXTERN_INLINE unsigned int mcpcia_ioread8(const void __iomem *xaddr)
 {
 	unsigned long addr = (unsigned long)xaddr & MCPCIA_MEM_MASK;
 	unsigned long hose = (unsigned long)xaddr & ~MCPCIA_MEM_MASK;
@@ -291,7 +291,7 @@ __EXTERN_INLINE void mcpcia_iowrite8(u8 b, void __iomem *xaddr)
 	*(vuip) ((addr << 5) + hose + 0x00) = w;
 }
 
-__EXTERN_INLINE unsigned int mcpcia_ioread16(void __iomem *xaddr)
+__EXTERN_INLINE unsigned int mcpcia_ioread16(const void __iomem *xaddr)
 {
 	unsigned long addr = (unsigned long)xaddr & MCPCIA_MEM_MASK;
 	unsigned long hose = (unsigned long)xaddr & ~MCPCIA_MEM_MASK;
@@ -315,7 +315,7 @@ __EXTERN_INLINE void mcpcia_iowrite16(u16 b, void __iomem *xaddr)
 	*(vuip) ((addr << 5) + hose + 0x08) = w;
 }
 
-__EXTERN_INLINE unsigned int mcpcia_ioread32(void __iomem *xaddr)
+__EXTERN_INLINE unsigned int mcpcia_ioread32(const void __iomem *xaddr)
 {
 	unsigned long addr = (unsigned long)xaddr;
 
diff --git a/arch/alpha/include/asm/core_t2.h b/arch/alpha/include/asm/core_t2.h
index e0b33d09e93a..12bb7addc789 100644
--- a/arch/alpha/include/asm/core_t2.h
+++ b/arch/alpha/include/asm/core_t2.h
@@ -572,7 +572,7 @@ __EXTERN_INLINE int t2_is_mmio(const volatile void __iomem *addr)
    it doesn't make sense to merge the pio and mmio routines.  */
 
 #define IOPORT(OS, NS)							\
-__EXTERN_INLINE unsigned int t2_ioread##NS(void __iomem *xaddr)		\
+__EXTERN_INLINE unsigned int t2_ioread##NS(const void __iomem *xaddr)		\
 {									\
 	if (t2_is_mmio(xaddr))						\
 		return t2_read##OS(xaddr);				\
diff --git a/arch/alpha/include/asm/io.h b/arch/alpha/include/asm/io.h
index d1ed5a8133c5..cc12ec74175c 100644
--- a/arch/alpha/include/asm/io.h
+++ b/arch/alpha/include/asm/io.h
@@ -151,9 +151,9 @@ static inline void generic_##NAME(TYPE b, QUAL void __iomem *addr)	\
 	alpha_mv.mv_##NAME(b, addr);					\
 }
 
-REMAP1(unsigned int, ioread8, /**/)
-REMAP1(unsigned int, ioread16, /**/)
-REMAP1(unsigned int, ioread32, /**/)
+REMAP1(unsigned int, ioread8, const)
+REMAP1(unsigned int, ioread16, const)
+REMAP1(unsigned int, ioread32, const)
 REMAP1(u8, readb, const volatile)
 REMAP1(u16, readw, const volatile)
 REMAP1(u32, readl, const volatile)
@@ -308,14 +308,14 @@ static inline int __is_mmio(const volatile void __iomem *addr)
  */
 
 #if IO_CONCAT(__IO_PREFIX,trivial_io_bw)
-extern inline unsigned int ioread8(void __iomem *addr)
+extern inline unsigned int ioread8(const void __iomem *addr)
 {
 	unsigned int ret = IO_CONCAT(__IO_PREFIX,ioread8)(addr);
 	mb();
 	return ret;
 }
 
-extern inline unsigned int ioread16(void __iomem *addr)
+extern inline unsigned int ioread16(const void __iomem *addr)
 {
 	unsigned int ret = IO_CONCAT(__IO_PREFIX,ioread16)(addr);
 	mb();
@@ -356,7 +356,7 @@ extern inline void outw(u16 b, unsigned long port)
 #endif
 
 #if IO_CONCAT(__IO_PREFIX,trivial_io_lq)
-extern inline unsigned int ioread32(void __iomem *addr)
+extern inline unsigned int ioread32(const void __iomem *addr)
 {
 	unsigned int ret = IO_CONCAT(__IO_PREFIX,ioread32)(addr);
 	mb();
diff --git a/arch/alpha/include/asm/io_trivial.h b/arch/alpha/include/asm/io_trivial.h
index ba3d8f0cfe0c..a1a29cbe02fa 100644
--- a/arch/alpha/include/asm/io_trivial.h
+++ b/arch/alpha/include/asm/io_trivial.h
@@ -7,15 +7,15 @@
 
 #if IO_CONCAT(__IO_PREFIX,trivial_io_bw)
 __EXTERN_INLINE unsigned int
-IO_CONCAT(__IO_PREFIX,ioread8)(void __iomem *a)
+IO_CONCAT(__IO_PREFIX,ioread8)(const void __iomem *a)
 {
-	return __kernel_ldbu(*(volatile u8 __force *)a);
+	return __kernel_ldbu(*(const volatile u8 __force *)a);
 }
 
 __EXTERN_INLINE unsigned int
-IO_CONCAT(__IO_PREFIX,ioread16)(void __iomem *a)
+IO_CONCAT(__IO_PREFIX,ioread16)(const void __iomem *a)
 {
-	return __kernel_ldwu(*(volatile u16 __force *)a);
+	return __kernel_ldwu(*(const volatile u16 __force *)a);
 }
 
 __EXTERN_INLINE void
@@ -33,9 +33,9 @@ IO_CONCAT(__IO_PREFIX,iowrite16)(u16 b, void __iomem *a)
 
 #if IO_CONCAT(__IO_PREFIX,trivial_io_lq)
 __EXTERN_INLINE unsigned int
-IO_CONCAT(__IO_PREFIX,ioread32)(void __iomem *a)
+IO_CONCAT(__IO_PREFIX,ioread32)(const void __iomem *a)
 {
-	return *(volatile u32 __force *)a;
+	return *(const volatile u32 __force *)a;
 }
 
 __EXTERN_INLINE void
@@ -73,14 +73,14 @@ IO_CONCAT(__IO_PREFIX,writew)(u16 b, volatile void __iomem *a)
 __EXTERN_INLINE u8
 IO_CONCAT(__IO_PREFIX,readb)(const volatile void __iomem *a)
 {
-	void __iomem *addr = (void __iomem *)a;
+	const void __iomem *addr = (const void __iomem *)a;
 	return IO_CONCAT(__IO_PREFIX,ioread8)(addr);
 }
 
 __EXTERN_INLINE u16
 IO_CONCAT(__IO_PREFIX,readw)(const volatile void __iomem *a)
 {
-	void __iomem *addr = (void __iomem *)a;
+	const void __iomem *addr = (const void __iomem *)a;
 	return IO_CONCAT(__IO_PREFIX,ioread16)(addr);
 }
 
diff --git a/arch/alpha/include/asm/jensen.h b/arch/alpha/include/asm/jensen.h
index 436dc905b6ad..916895155a88 100644
--- a/arch/alpha/include/asm/jensen.h
+++ b/arch/alpha/include/asm/jensen.h
@@ -305,7 +305,7 @@ __EXTERN_INLINE int jensen_is_mmio(const volatile void __iomem *addr)
    that it doesn't make sense to merge them.  */
 
 #define IOPORT(OS, NS)							\
-__EXTERN_INLINE unsigned int jensen_ioread##NS(void __iomem *xaddr)	\
+__EXTERN_INLINE unsigned int jensen_ioread##NS(const void __iomem *xaddr)	\
 {									\
 	if (jensen_is_mmio(xaddr))					\
 		return jensen_read##OS(xaddr - 0x100000000ul);		\
diff --git a/arch/alpha/include/asm/machvec.h b/arch/alpha/include/asm/machvec.h
index a6b73c6d10ee..a4e96e2bec74 100644
--- a/arch/alpha/include/asm/machvec.h
+++ b/arch/alpha/include/asm/machvec.h
@@ -46,9 +46,9 @@ struct alpha_machine_vector
 	void (*mv_pci_tbi)(struct pci_controller *hose,
 			   dma_addr_t start, dma_addr_t end);
 
-	unsigned int (*mv_ioread8)(void __iomem *);
-	unsigned int (*mv_ioread16)(void __iomem *);
-	unsigned int (*mv_ioread32)(void __iomem *);
+	unsigned int (*mv_ioread8)(const void __iomem *);
+	unsigned int (*mv_ioread16)(const void __iomem *);
+	unsigned int (*mv_ioread32)(const void __iomem *);
 
 	void (*mv_iowrite8)(u8, void __iomem *);
 	void (*mv_iowrite16)(u16, void __iomem *);
diff --git a/arch/alpha/kernel/core_marvel.c b/arch/alpha/kernel/core_marvel.c
index 1db9d0eb2922..37514422f586 100644
--- a/arch/alpha/kernel/core_marvel.c
+++ b/arch/alpha/kernel/core_marvel.c
@@ -807,7 +807,7 @@ void __iomem *marvel_ioportmap (unsigned long addr)
 }
 
 unsigned int
-marvel_ioread8(void __iomem *xaddr)
+marvel_ioread8(const void __iomem *xaddr)
 {
 	unsigned long addr = (unsigned long) xaddr;
 	if (__marvel_is_port_kbd(addr))
diff --git a/arch/alpha/kernel/io.c b/arch/alpha/kernel/io.c
index c025a3e5e357..e49918b91fee 100644
--- a/arch/alpha/kernel/io.c
+++ b/arch/alpha/kernel/io.c
@@ -14,21 +14,21 @@
    "generic", which bumps through the machine vector.  */
 
 unsigned int
-ioread8(void __iomem *addr)
+ioread8(const void __iomem *addr)
 {
 	unsigned int ret = IO_CONCAT(__IO_PREFIX,ioread8)(addr);
 	mb();
 	return ret;
 }
 
-unsigned int ioread16(void __iomem *addr)
+unsigned int ioread16(const void __iomem *addr)
 {
 	unsigned int ret = IO_CONCAT(__IO_PREFIX,ioread16)(addr);
 	mb();
 	return ret;
 }
 
-unsigned int ioread32(void __iomem *addr)
+unsigned int ioread32(const void __iomem *addr)
 {
 	unsigned int ret = IO_CONCAT(__IO_PREFIX,ioread32)(addr);
 	mb();
-- 
2.7.4


_______________________________________________
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http://lists.infradead.org/mailman/listinfo/linux-snps-arc

^ permalink raw reply	[flat|nested] 31+ messages in thread

* [RFT 03/13] sh: Constify ioreadX() iomem argument (as in generic implementation)
  2020-01-07 16:52 [RFT 00/13] iomap: Constify ioreadX() iomem argument Krzysztof Kozlowski
                   ` (3 preceding siblings ...)
  2020-01-07 16:53 ` [RFT 03/13] alpha: " Krzysztof Kozlowski
@ 2020-01-07 16:53 ` " Krzysztof Kozlowski
  2020-01-07 17:08   ` Arnd Bergmann
  2020-01-07 16:53 ` [RFT 04/13] parisc: " Krzysztof Kozlowski
                   ` (10 subsequent siblings)
  15 siblings, 1 reply; 31+ messages in thread
From: Krzysztof Kozlowski @ 2020-01-07 16:53 UTC (permalink / raw)
  To: Richard Henderson, Ivan Kokshaysky, Matt Turner, Alexey Brodkin,
	Vineet Gupta, James E.J. Bottomley, Helge Deller,
	Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman,
	Yoshinori Sato, Rich Felker, Dave Airlie, David Airlie,
	Daniel Vetter, Ben Skeggs, Mauro Carvalho Chehab, Jiri Slaby,
	Nick Kossifidis, Luis Chamberlain, Kalle Valo, David S. Miller,
	Dave Jiang, Jon Mason, Allen Hubbe, Michael S. Tsirkin,
	Jason Wang, Arnd Bergmann, Andrew Morton, Thomas Gleixner,
	Geert Uytterhoeven, linux-alpha, linux-kernel, linux-snps-arc,
	linux-parisc, linuxppc-dev, linux-sh, dri-devel, nouveau,
	linux-media, linux-wireless, netdev, linux-ntb, virtualization,
	linux-arch
  Cc: Krzysztof Kozlowski

The ioreadX() 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.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
---
 arch/sh/kernel/iomap.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/arch/sh/kernel/iomap.c b/arch/sh/kernel/iomap.c
index ef9e2c97cbb7..bd5e212c6ea6 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));
 }
-- 
2.7.4


_______________________________________________
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linux-snps-arc@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-snps-arc

^ permalink raw reply	[flat|nested] 31+ messages in thread

* [RFT 04/13] parisc: Constify ioreadX() iomem argument (as in generic implementation)
  2020-01-07 16:52 [RFT 00/13] iomap: Constify ioreadX() iomem argument Krzysztof Kozlowski
                   ` (4 preceding siblings ...)
  2020-01-07 16:53 ` [RFT 03/13] sh: " Krzysztof Kozlowski
@ 2020-01-07 16:53 ` " Krzysztof Kozlowski
  2020-01-07 16:53 ` [RFT 05/13] powerpc: " Krzysztof Kozlowski
                   ` (9 subsequent siblings)
  15 siblings, 0 replies; 31+ messages in thread
From: Krzysztof Kozlowski @ 2020-01-07 16:53 UTC (permalink / raw)
  To: Richard Henderson, Ivan Kokshaysky, Matt Turner, Alexey Brodkin,
	Vineet Gupta, James E.J. Bottomley, Helge Deller,
	Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman,
	Yoshinori Sato, Rich Felker, Dave Airlie, David Airlie,
	Daniel Vetter, Ben Skeggs, Mauro Carvalho Chehab, Jiri Slaby,
	Nick Kossifidis, Luis Chamberlain, Kalle Valo, David S. Miller,
	Dave Jiang, Jon Mason, Allen Hubbe, Michael S. Tsirkin,
	Jason Wang, Arnd Bergmann, Andrew Morton, Thomas Gleixner,
	Geert Uytterhoeven, linux-alpha, linux-kernel, linux-snps-arc,
	linux-parisc, linuxppc-dev, linux-sh, dri-devel, nouveau,
	linux-media, linux-wireless, netdev, linux-ntb, virtualization,
	linux-arch
  Cc: Krzysztof Kozlowski

The ioreadX() 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.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
---
 arch/parisc/include/asm/io.h |  4 ++--
 arch/parisc/lib/iomap.c      | 48 ++++++++++++++++++++++----------------------
 2 files changed, 26 insertions(+), 26 deletions(-)

diff --git a/arch/parisc/include/asm/io.h b/arch/parisc/include/asm/io.h
index cab8f64ca4a2..f48fb8d76e15 100644
--- a/arch/parisc/include/asm/io.h
+++ b/arch/parisc/include/asm/io.h
@@ -303,8 +303,8 @@ extern void outsl (unsigned long port, const void *src, unsigned long count);
 #define ioread64be ioread64be
 #define iowrite64 iowrite64
 #define iowrite64be iowrite64be
-extern u64 ioread64(void __iomem *addr);
-extern u64 ioread64be(void __iomem *addr);
+extern u64 ioread64(const void __iomem *addr);
+extern u64 ioread64be(const void __iomem *addr);
 extern void iowrite64(u64 val, void __iomem *addr);
 extern void iowrite64be(u64 val, void __iomem *addr);
 
diff --git a/arch/parisc/lib/iomap.c b/arch/parisc/lib/iomap.c
index 0195aec657e2..e01345d2a7d9 100644
--- a/arch/parisc/lib/iomap.c
+++ b/arch/parisc/lib/iomap.c
@@ -43,13 +43,13 @@
 #endif
 
 struct iomap_ops {
-	unsigned int (*read8)(void __iomem *);
-	unsigned int (*read16)(void __iomem *);
-	unsigned int (*read16be)(void __iomem *);
-	unsigned int (*read32)(void __iomem *);
-	unsigned int (*read32be)(void __iomem *);
-	u64 (*read64)(void __iomem *);
-	u64 (*read64be)(void __iomem *);
+	unsigned int (*read8)(const void __iomem *);
+	unsigned int (*read16)(const void __iomem *);
+	unsigned int (*read16be)(const void __iomem *);
+	unsigned int (*read32)(const void __iomem *);
+	unsigned int (*read32be)(const void __iomem *);
+	u64 (*read64)(const void __iomem *);
+	u64 (*read64be)(const void __iomem *);
 	void (*write8)(u8, void __iomem *);
 	void (*write16)(u16, void __iomem *);
 	void (*write16be)(u16, void __iomem *);
@@ -69,17 +69,17 @@ struct iomap_ops {
 
 #define ADDR2PORT(addr) ((unsigned long __force)(addr) & 0xffffff)
 
-static unsigned int ioport_read8(void __iomem *addr)
+static unsigned int ioport_read8(const void __iomem *addr)
 {
 	return inb(ADDR2PORT(addr));
 }
 
-static unsigned int ioport_read16(void __iomem *addr)
+static unsigned int ioport_read16(const void __iomem *addr)
 {
 	return inw(ADDR2PORT(addr));
 }
 
-static unsigned int ioport_read32(void __iomem *addr)
+static unsigned int ioport_read32(const void __iomem *addr)
 {
 	return inl(ADDR2PORT(addr));
 }
@@ -150,37 +150,37 @@ static const struct iomap_ops ioport_ops = {
 
 /* Legacy I/O memory ops */
 
-static unsigned int iomem_read8(void __iomem *addr)
+static unsigned int iomem_read8(const void __iomem *addr)
 {
 	return readb(addr);
 }
 
-static unsigned int iomem_read16(void __iomem *addr)
+static unsigned int iomem_read16(const void __iomem *addr)
 {
 	return readw(addr);
 }
 
-static unsigned int iomem_read16be(void __iomem *addr)
+static unsigned int iomem_read16be(const void __iomem *addr)
 {
 	return __raw_readw(addr);
 }
 
-static unsigned int iomem_read32(void __iomem *addr)
+static unsigned int iomem_read32(const void __iomem *addr)
 {
 	return readl(addr);
 }
 
-static unsigned int iomem_read32be(void __iomem *addr)
+static unsigned int iomem_read32be(const void __iomem *addr)
 {
 	return __raw_readl(addr);
 }
 
-static u64 iomem_read64(void __iomem *addr)
+static u64 iomem_read64(const void __iomem *addr)
 {
 	return readq(addr);
 }
 
-static u64 iomem_read64be(void __iomem *addr)
+static u64 iomem_read64be(const void __iomem *addr)
 {
 	return __raw_readq(addr);
 }
@@ -297,49 +297,49 @@ static const struct iomap_ops *iomap_ops[8] = {
 };
 
 
-unsigned int ioread8(void __iomem *addr)
+unsigned int ioread8(const void __iomem *addr)
 {
 	if (unlikely(INDIRECT_ADDR(addr)))
 		return iomap_ops[ADDR_TO_REGION(addr)]->read8(addr);
 	return *((u8 *)addr);
 }
 
-unsigned int ioread16(void __iomem *addr)
+unsigned int ioread16(const void __iomem *addr)
 {
 	if (unlikely(INDIRECT_ADDR(addr)))
 		return iomap_ops[ADDR_TO_REGION(addr)]->read16(addr);
 	return le16_to_cpup((u16 *)addr);
 }
 
-unsigned int ioread16be(void __iomem *addr)
+unsigned int ioread16be(const void __iomem *addr)
 {
 	if (unlikely(INDIRECT_ADDR(addr)))
 		return iomap_ops[ADDR_TO_REGION(addr)]->read16be(addr);
 	return *((u16 *)addr);
 }
 
-unsigned int ioread32(void __iomem *addr)
+unsigned int ioread32(const void __iomem *addr)
 {
 	if (unlikely(INDIRECT_ADDR(addr)))
 		return iomap_ops[ADDR_TO_REGION(addr)]->read32(addr);
 	return le32_to_cpup((u32 *)addr);
 }
 
-unsigned int ioread32be(void __iomem *addr)
+unsigned int ioread32be(const void __iomem *addr)
 {
 	if (unlikely(INDIRECT_ADDR(addr)))
 		return iomap_ops[ADDR_TO_REGION(addr)]->read32be(addr);
 	return *((u32 *)addr);
 }
 
-u64 ioread64(void __iomem *addr)
+u64 ioread64(const void __iomem *addr)
 {
 	if (unlikely(INDIRECT_ADDR(addr)))
 		return iomap_ops[ADDR_TO_REGION(addr)]->read64(addr);
 	return le64_to_cpup((u64 *)addr);
 }
 
-u64 ioread64be(void __iomem *addr)
+u64 ioread64be(const void __iomem *addr)
 {
 	if (unlikely(INDIRECT_ADDR(addr)))
 		return iomap_ops[ADDR_TO_REGION(addr)]->read64be(addr);
-- 
2.7.4


_______________________________________________
linux-snps-arc mailing list
linux-snps-arc@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-snps-arc

^ permalink raw reply	[flat|nested] 31+ messages in thread

* [RFT 05/13] powerpc: Constify ioreadX() iomem argument (as in generic implementation)
  2020-01-07 16:52 [RFT 00/13] iomap: Constify ioreadX() iomem argument Krzysztof Kozlowski
                   ` (5 preceding siblings ...)
  2020-01-07 16:53 ` [RFT 04/13] parisc: " Krzysztof Kozlowski
@ 2020-01-07 16:53 ` " Krzysztof Kozlowski
  2020-01-07 16:53 ` [RFT 06/13] arc: " Krzysztof Kozlowski
                   ` (8 subsequent siblings)
  15 siblings, 0 replies; 31+ messages in thread
From: Krzysztof Kozlowski @ 2020-01-07 16:53 UTC (permalink / raw)
  To: Richard Henderson, Ivan Kokshaysky, Matt Turner, Alexey Brodkin,
	Vineet Gupta, James E.J. Bottomley, Helge Deller,
	Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman,
	Yoshinori Sato, Rich Felker, Dave Airlie, David Airlie,
	Daniel Vetter, Ben Skeggs, Mauro Carvalho Chehab, Jiri Slaby,
	Nick Kossifidis, Luis Chamberlain, Kalle Valo, David S. Miller,
	Dave Jiang, Jon Mason, Allen Hubbe, Michael S. Tsirkin,
	Jason Wang, Arnd Bergmann, Andrew Morton, Thomas Gleixner,
	Geert Uytterhoeven, linux-alpha, linux-kernel, linux-snps-arc,
	linux-parisc, linuxppc-dev, linux-sh, dri-devel, nouveau,
	linux-media, linux-wireless, netdev, linux-ntb, virtualization,
	linux-arch
  Cc: Krzysztof Kozlowski

The ioreadX() 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.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
---
 arch/powerpc/kernel/iomap.c | 22 +++++++++++-----------
 1 file changed, 11 insertions(+), 11 deletions(-)

diff --git a/arch/powerpc/kernel/iomap.c b/arch/powerpc/kernel/iomap.c
index 5ac84efc6ede..de8da1c3496f 100644
--- a/arch/powerpc/kernel/iomap.c
+++ b/arch/powerpc/kernel/iomap.c
@@ -15,23 +15,23 @@
  * Here comes the ppc64 implementation of the IOMAP 
  * interfaces.
  */
-unsigned int ioread8(void __iomem *addr)
+unsigned int ioread8(const void __iomem *addr)
 {
 	return readb(addr);
 }
-unsigned int ioread16(void __iomem *addr)
+unsigned int ioread16(const void __iomem *addr)
 {
 	return readw(addr);
 }
-unsigned int ioread16be(void __iomem *addr)
+unsigned int ioread16be(const void __iomem *addr)
 {
 	return readw_be(addr);
 }
-unsigned int ioread32(void __iomem *addr)
+unsigned int ioread32(const void __iomem *addr)
 {
 	return readl(addr);
 }
-unsigned int ioread32be(void __iomem *addr)
+unsigned int ioread32be(const void __iomem *addr)
 {
 	return readl_be(addr);
 }
@@ -41,27 +41,27 @@ EXPORT_SYMBOL(ioread16be);
 EXPORT_SYMBOL(ioread32);
 EXPORT_SYMBOL(ioread32be);
 #ifdef __powerpc64__
-u64 ioread64(void __iomem *addr)
+u64 ioread64(const void __iomem *addr)
 {
 	return readq(addr);
 }
-u64 ioread64_lo_hi(void __iomem *addr)
+u64 ioread64_lo_hi(const void __iomem *addr)
 {
 	return readq(addr);
 }
-u64 ioread64_hi_lo(void __iomem *addr)
+u64 ioread64_hi_lo(const void __iomem *addr)
 {
 	return readq(addr);
 }
-u64 ioread64be(void __iomem *addr)
+u64 ioread64be(const void __iomem *addr)
 {
 	return readq_be(addr);
 }
-u64 ioread64be_lo_hi(void __iomem *addr)
+u64 ioread64be_lo_hi(const void __iomem *addr)
 {
 	return readq_be(addr);
 }
-u64 ioread64be_hi_lo(void __iomem *addr)
+u64 ioread64be_hi_lo(const void __iomem *addr)
 {
 	return readq_be(addr);
 }
-- 
2.7.4


_______________________________________________
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http://lists.infradead.org/mailman/listinfo/linux-snps-arc

^ permalink raw reply	[flat|nested] 31+ messages in thread

* [RFT 06/13] arc: Constify ioreadX() iomem argument (as in generic implementation)
  2020-01-07 16:52 [RFT 00/13] iomap: Constify ioreadX() iomem argument Krzysztof Kozlowski
                   ` (6 preceding siblings ...)
  2020-01-07 16:53 ` [RFT 05/13] powerpc: " Krzysztof Kozlowski
@ 2020-01-07 16:53 ` " Krzysztof Kozlowski
  2020-01-07 17:10   ` Arnd Bergmann
  2020-01-07 16:53 ` [RFT 07/13] drm/mgag200: " Krzysztof Kozlowski
                   ` (7 subsequent siblings)
  15 siblings, 1 reply; 31+ messages in thread
From: Krzysztof Kozlowski @ 2020-01-07 16:53 UTC (permalink / raw)
  To: Richard Henderson, Ivan Kokshaysky, Matt Turner, Alexey Brodkin,
	Vineet Gupta, James E.J. Bottomley, Helge Deller,
	Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman,
	Yoshinori Sato, Rich Felker, Dave Airlie, David Airlie,
	Daniel Vetter, Ben Skeggs, Mauro Carvalho Chehab, Jiri Slaby,
	Nick Kossifidis, Luis Chamberlain, Kalle Valo, David S. Miller,
	Dave Jiang, Jon Mason, Allen Hubbe, Michael S. Tsirkin,
	Jason Wang, Arnd Bergmann, Andrew Morton, Thomas Gleixner,
	Geert Uytterhoeven, linux-alpha, linux-kernel, linux-snps-arc,
	linux-parisc, linuxppc-dev, linux-sh, dri-devel, nouveau,
	linux-media, linux-wireless, netdev, linux-ntb, virtualization,
	linux-arch
  Cc: Krzysztof Kozlowski

The ioreadX() 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.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
---
 arch/arc/plat-axs10x/axs10x.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/arc/plat-axs10x/axs10x.c b/arch/arc/plat-axs10x/axs10x.c
index 63ea5a606ecd..180c260a8221 100644
--- a/arch/arc/plat-axs10x/axs10x.c
+++ b/arch/arc/plat-axs10x/axs10x.c
@@ -84,7 +84,7 @@ static void __init axs10x_print_board_ver(unsigned int creg, const char *str)
 		unsigned int val;
 	} board;
 
-	board.val = ioread32((void __iomem *)creg);
+	board.val = ioread32((const void __iomem *)creg);
 	pr_info("AXS: %s FPGA Date: %u-%u-%u\n", str, board.d, board.m,
 		board.y);
 }
@@ -95,7 +95,7 @@ static void __init axs10x_early_init(void)
 	char mb[32];
 
 	/* Determine motherboard version */
-	if (ioread32((void __iomem *) CREG_MB_CONFIG) & (1 << 28))
+	if (ioread32((const void __iomem *) CREG_MB_CONFIG) & (1 << 28))
 		mb_rev = 3;	/* HT-3 (rev3.0) */
 	else
 		mb_rev = 2;	/* HT-2 (rev2.0) */
-- 
2.7.4


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^ permalink raw reply	[flat|nested] 31+ messages in thread

* [RFT 07/13] drm/mgag200: Constify ioreadX() iomem argument (as in generic implementation)
  2020-01-07 16:52 [RFT 00/13] iomap: Constify ioreadX() iomem argument Krzysztof Kozlowski
                   ` (7 preceding siblings ...)
  2020-01-07 16:53 ` [RFT 06/13] arc: " Krzysztof Kozlowski
@ 2020-01-07 16:53 ` " Krzysztof Kozlowski
  2020-01-07 16:53 ` [RFT 08/13] drm/nouveau: " Krzysztof Kozlowski
                   ` (6 subsequent siblings)
  15 siblings, 0 replies; 31+ messages in thread
From: Krzysztof Kozlowski @ 2020-01-07 16:53 UTC (permalink / raw)
  To: Richard Henderson, Ivan Kokshaysky, Matt Turner, Alexey Brodkin,
	Vineet Gupta, James E.J. Bottomley, Helge Deller,
	Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman,
	Yoshinori Sato, Rich Felker, Dave Airlie, David Airlie,
	Daniel Vetter, Ben Skeggs, Mauro Carvalho Chehab, Jiri Slaby,
	Nick Kossifidis, Luis Chamberlain, Kalle Valo, David S. Miller,
	Dave Jiang, Jon Mason, Allen Hubbe, Michael S. Tsirkin,
	Jason Wang, Arnd Bergmann, Andrew Morton, Thomas Gleixner,
	Geert Uytterhoeven, linux-alpha, linux-kernel, linux-snps-arc,
	linux-parisc, linuxppc-dev, linux-sh, dri-devel, nouveau,
	linux-media, linux-wireless, netdev, linux-ntb, virtualization,
	linux-arch
  Cc: Krzysztof Kozlowski

The ioreadX() 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.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
---
 drivers/gpu/drm/mgag200/mgag200_drv.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/mgag200/mgag200_drv.h b/drivers/gpu/drm/mgag200/mgag200_drv.h
index aa32aad222c2..6512b3af4fb7 100644
--- a/drivers/gpu/drm/mgag200/mgag200_drv.h
+++ b/drivers/gpu/drm/mgag200/mgag200_drv.h
@@ -34,9 +34,9 @@
 
 #define MGAG200FB_CONN_LIMIT 1
 
-#define RREG8(reg) ioread8(((void __iomem *)mdev->rmmio) + (reg))
+#define RREG8(reg) ioread8(((const void __iomem *)mdev->rmmio) + (reg))
 #define WREG8(reg, v) iowrite8(v, ((void __iomem *)mdev->rmmio) + (reg))
-#define RREG32(reg) ioread32(((void __iomem *)mdev->rmmio) + (reg))
+#define RREG32(reg) ioread32(((const void __iomem *)mdev->rmmio) + (reg))
 #define WREG32(reg, v) iowrite32(v, ((void __iomem *)mdev->rmmio) + (reg))
 
 #define ATTR_INDEX 0x1fc0
-- 
2.7.4


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http://lists.infradead.org/mailman/listinfo/linux-snps-arc

^ permalink raw reply	[flat|nested] 31+ messages in thread

* [RFT 08/13] drm/nouveau: Constify ioreadX() iomem argument (as in generic implementation)
  2020-01-07 16:52 [RFT 00/13] iomap: Constify ioreadX() iomem argument Krzysztof Kozlowski
                   ` (8 preceding siblings ...)
  2020-01-07 16:53 ` [RFT 07/13] drm/mgag200: " Krzysztof Kozlowski
@ 2020-01-07 16:53 ` " Krzysztof Kozlowski
  2020-01-07 16:53 ` [RFT 09/13] media: fsl-viu: " Krzysztof Kozlowski
                   ` (5 subsequent siblings)
  15 siblings, 0 replies; 31+ messages in thread
From: Krzysztof Kozlowski @ 2020-01-07 16:53 UTC (permalink / raw)
  To: Richard Henderson, Ivan Kokshaysky, Matt Turner, Alexey Brodkin,
	Vineet Gupta, James E.J. Bottomley, Helge Deller,
	Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman,
	Yoshinori Sato, Rich Felker, Dave Airlie, David Airlie,
	Daniel Vetter, Ben Skeggs, Mauro Carvalho Chehab, Jiri Slaby,
	Nick Kossifidis, Luis Chamberlain, Kalle Valo, David S. Miller,
	Dave Jiang, Jon Mason, Allen Hubbe, Michael S. Tsirkin,
	Jason Wang, Arnd Bergmann, Andrew Morton, Thomas Gleixner,
	Geert Uytterhoeven, linux-alpha, linux-kernel, linux-snps-arc,
	linux-parisc, linuxppc-dev, linux-sh, dri-devel, nouveau,
	linux-media, linux-wireless, netdev, linux-ntb, virtualization,
	linux-arch
  Cc: Krzysztof Kozlowski

The ioreadX() 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.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
---
 drivers/gpu/drm/nouveau/nouveau_bo.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/nouveau/nouveau_bo.c b/drivers/gpu/drm/nouveau/nouveau_bo.c
index f8015e0318d7..5120d062c2df 100644
--- a/drivers/gpu/drm/nouveau/nouveau_bo.c
+++ b/drivers/gpu/drm/nouveau/nouveau_bo.c
@@ -613,7 +613,7 @@ nouveau_bo_rd32(struct nouveau_bo *nvbo, unsigned index)
 	mem += index;
 
 	if (is_iomem)
-		return ioread32_native((void __force __iomem *)mem);
+		return ioread32_native((const void __force __iomem *)mem);
 	else
 		return *mem;
 }
-- 
2.7.4


_______________________________________________
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http://lists.infradead.org/mailman/listinfo/linux-snps-arc

^ permalink raw reply	[flat|nested] 31+ messages in thread

* [RFT 09/13] media: fsl-viu: Constify ioreadX() iomem argument (as in generic implementation)
  2020-01-07 16:52 [RFT 00/13] iomap: Constify ioreadX() iomem argument Krzysztof Kozlowski
                   ` (9 preceding siblings ...)
  2020-01-07 16:53 ` [RFT 08/13] drm/nouveau: " Krzysztof Kozlowski
@ 2020-01-07 16:53 ` " Krzysztof Kozlowski
  2020-01-07 16:53 ` [RFT 10/13] net: wireless: ath5k: " Krzysztof Kozlowski
                   ` (4 subsequent siblings)
  15 siblings, 0 replies; 31+ messages in thread
From: Krzysztof Kozlowski @ 2020-01-07 16:53 UTC (permalink / raw)
  To: Richard Henderson, Ivan Kokshaysky, Matt Turner, Alexey Brodkin,
	Vineet Gupta, James E.J. Bottomley, Helge Deller,
	Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman,
	Yoshinori Sato, Rich Felker, Dave Airlie, David Airlie,
	Daniel Vetter, Ben Skeggs, Mauro Carvalho Chehab, Jiri Slaby,
	Nick Kossifidis, Luis Chamberlain, Kalle Valo, David S. Miller,
	Dave Jiang, Jon Mason, Allen Hubbe, Michael S. Tsirkin,
	Jason Wang, Arnd Bergmann, Andrew Morton, Thomas Gleixner,
	Geert Uytterhoeven, linux-alpha, linux-kernel, linux-snps-arc,
	linux-parisc, linuxppc-dev, linux-sh, dri-devel, nouveau,
	linux-media, linux-wireless, netdev, linux-ntb, virtualization,
	linux-arch
  Cc: Krzysztof Kozlowski

The ioreadX() 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.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
---
 drivers/media/platform/fsl-viu.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/media/platform/fsl-viu.c b/drivers/media/platform/fsl-viu.c
index 81a8faedbba6..991d9dc82749 100644
--- a/drivers/media/platform/fsl-viu.c
+++ b/drivers/media/platform/fsl-viu.c
@@ -34,7 +34,7 @@
 /* Allow building this driver with COMPILE_TEST */
 #if !defined(CONFIG_PPC) && !defined(CONFIG_MICROBLAZE)
 #define out_be32(v, a)	iowrite32be(a, (void __iomem *)v)
-#define in_be32(a)	ioread32be((void __iomem *)a)
+#define in_be32(a)	ioread32be((const void __iomem *)a)
 #endif
 
 #define BUFFER_TIMEOUT		msecs_to_jiffies(500)  /* 0.5 seconds */
-- 
2.7.4


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http://lists.infradead.org/mailman/listinfo/linux-snps-arc

^ permalink raw reply	[flat|nested] 31+ messages in thread

* [RFT 10/13] net: wireless: ath5k: Constify ioreadX() iomem argument (as in generic implementation)
  2020-01-07 16:52 [RFT 00/13] iomap: Constify ioreadX() iomem argument Krzysztof Kozlowski
                   ` (10 preceding siblings ...)
  2020-01-07 16:53 ` [RFT 09/13] media: fsl-viu: " Krzysztof Kozlowski
@ 2020-01-07 16:53 ` " Krzysztof Kozlowski
  2020-01-07 16:53 ` [RFT 11/13] net: wireless: rtl818x: " Krzysztof Kozlowski
                   ` (3 subsequent siblings)
  15 siblings, 0 replies; 31+ messages in thread
From: Krzysztof Kozlowski @ 2020-01-07 16:53 UTC (permalink / raw)
  To: Richard Henderson, Ivan Kokshaysky, Matt Turner, Alexey Brodkin,
	Vineet Gupta, James E.J. Bottomley, Helge Deller,
	Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman,
	Yoshinori Sato, Rich Felker, Dave Airlie, David Airlie,
	Daniel Vetter, Ben Skeggs, Mauro Carvalho Chehab, Jiri Slaby,
	Nick Kossifidis, Luis Chamberlain, Kalle Valo, David S. Miller,
	Dave Jiang, Jon Mason, Allen Hubbe, Michael S. Tsirkin,
	Jason Wang, Arnd Bergmann, Andrew Morton, Thomas Gleixner,
	Geert Uytterhoeven, linux-alpha, linux-kernel, linux-snps-arc,
	linux-parisc, linuxppc-dev, linux-sh, dri-devel, nouveau,
	linux-media, linux-wireless, netdev, linux-ntb, virtualization,
	linux-arch
  Cc: Krzysztof Kozlowski

The ioreadX() 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.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
---
 drivers/net/wireless/ath/ath5k/ahb.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/net/wireless/ath/ath5k/ahb.c b/drivers/net/wireless/ath/ath5k/ahb.c
index 2c9cec8b53d9..8bd01df369fb 100644
--- a/drivers/net/wireless/ath/ath5k/ahb.c
+++ b/drivers/net/wireless/ath/ath5k/ahb.c
@@ -138,18 +138,18 @@ static int ath_ahb_probe(struct platform_device *pdev)
 
 	if (bcfg->devid >= AR5K_SREV_AR2315_R6) {
 		/* Enable WMAC AHB arbitration */
-		reg = ioread32((void __iomem *) AR5K_AR2315_AHB_ARB_CTL);
+		reg = ioread32((const void __iomem *) AR5K_AR2315_AHB_ARB_CTL);
 		reg |= AR5K_AR2315_AHB_ARB_CTL_WLAN;
 		iowrite32(reg, (void __iomem *) AR5K_AR2315_AHB_ARB_CTL);
 
 		/* Enable global WMAC swapping */
-		reg = ioread32((void __iomem *) AR5K_AR2315_BYTESWAP);
+		reg = ioread32((const void __iomem *) AR5K_AR2315_BYTESWAP);
 		reg |= AR5K_AR2315_BYTESWAP_WMAC;
 		iowrite32(reg, (void __iomem *) AR5K_AR2315_BYTESWAP);
 	} else {
 		/* Enable WMAC DMA access (assuming 5312 or 231x*/
 		/* TODO: check other platforms */
-		reg = ioread32((void __iomem *) AR5K_AR5312_ENABLE);
+		reg = ioread32((const void __iomem *) AR5K_AR5312_ENABLE);
 		if (to_platform_device(ah->dev)->id == 0)
 			reg |= AR5K_AR5312_ENABLE_WLAN0;
 		else
@@ -202,12 +202,12 @@ static int ath_ahb_remove(struct platform_device *pdev)
 
 	if (bcfg->devid >= AR5K_SREV_AR2315_R6) {
 		/* Disable WMAC AHB arbitration */
-		reg = ioread32((void __iomem *) AR5K_AR2315_AHB_ARB_CTL);
+		reg = ioread32((const void __iomem *) AR5K_AR2315_AHB_ARB_CTL);
 		reg &= ~AR5K_AR2315_AHB_ARB_CTL_WLAN;
 		iowrite32(reg, (void __iomem *) AR5K_AR2315_AHB_ARB_CTL);
 	} else {
 		/*Stop DMA access */
-		reg = ioread32((void __iomem *) AR5K_AR5312_ENABLE);
+		reg = ioread32((const void __iomem *) AR5K_AR5312_ENABLE);
 		if (to_platform_device(ah->dev)->id == 0)
 			reg &= ~AR5K_AR5312_ENABLE_WLAN0;
 		else
-- 
2.7.4


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http://lists.infradead.org/mailman/listinfo/linux-snps-arc

^ permalink raw reply	[flat|nested] 31+ messages in thread

* [RFT 11/13] net: wireless: rtl818x: Constify ioreadX() iomem argument (as in generic implementation)
  2020-01-07 16:52 [RFT 00/13] iomap: Constify ioreadX() iomem argument Krzysztof Kozlowski
                   ` (11 preceding siblings ...)
  2020-01-07 16:53 ` [RFT 10/13] net: wireless: ath5k: " Krzysztof Kozlowski
@ 2020-01-07 16:53 ` " Krzysztof Kozlowski
  2020-01-07 16:53 ` [RFT 12/13] ntb: intel: " Krzysztof Kozlowski
                   ` (2 subsequent siblings)
  15 siblings, 0 replies; 31+ messages in thread
From: Krzysztof Kozlowski @ 2020-01-07 16:53 UTC (permalink / raw)
  To: Richard Henderson, Ivan Kokshaysky, Matt Turner, Alexey Brodkin,
	Vineet Gupta, James E.J. Bottomley, Helge Deller,
	Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman,
	Yoshinori Sato, Rich Felker, Dave Airlie, David Airlie,
	Daniel Vetter, Ben Skeggs, Mauro Carvalho Chehab, Jiri Slaby,
	Nick Kossifidis, Luis Chamberlain, Kalle Valo, David S. Miller,
	Dave Jiang, Jon Mason, Allen Hubbe, Michael S. Tsirkin,
	Jason Wang, Arnd Bergmann, Andrew Morton, Thomas Gleixner,
	Geert Uytterhoeven, linux-alpha, linux-kernel, linux-snps-arc,
	linux-parisc, linuxppc-dev, linux-sh, dri-devel, nouveau,
	linux-media, linux-wireless, netdev, linux-ntb, virtualization,
	linux-arch
  Cc: Krzysztof Kozlowski

The ioreadX() 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.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
---
 drivers/net/wireless/realtek/rtl818x/rtl8180/rtl8180.h | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/net/wireless/realtek/rtl818x/rtl8180/rtl8180.h b/drivers/net/wireless/realtek/rtl818x/rtl8180/rtl8180.h
index 7948a2da195a..2ff00800d45b 100644
--- a/drivers/net/wireless/realtek/rtl818x/rtl8180/rtl8180.h
+++ b/drivers/net/wireless/realtek/rtl818x/rtl8180/rtl8180.h
@@ -150,17 +150,17 @@ void rtl8180_write_phy(struct ieee80211_hw *dev, u8 addr, u32 data);
 void rtl8180_set_anaparam(struct rtl8180_priv *priv, u32 anaparam);
 void rtl8180_set_anaparam2(struct rtl8180_priv *priv, u32 anaparam2);
 
-static inline u8 rtl818x_ioread8(struct rtl8180_priv *priv, u8 __iomem *addr)
+static inline u8 rtl818x_ioread8(struct rtl8180_priv *priv, const u8 __iomem *addr)
 {
 	return ioread8(addr);
 }
 
-static inline u16 rtl818x_ioread16(struct rtl8180_priv *priv, __le16 __iomem *addr)
+static inline u16 rtl818x_ioread16(struct rtl8180_priv *priv, const __le16 __iomem *addr)
 {
 	return ioread16(addr);
 }
 
-static inline u32 rtl818x_ioread32(struct rtl8180_priv *priv, __le32 __iomem *addr)
+static inline u32 rtl818x_ioread32(struct rtl8180_priv *priv, const __le32 __iomem *addr)
 {
 	return ioread32(addr);
 }
-- 
2.7.4


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http://lists.infradead.org/mailman/listinfo/linux-snps-arc

^ permalink raw reply	[flat|nested] 31+ messages in thread

* [RFT 12/13] ntb: intel: Constify ioreadX() iomem argument (as in generic implementation)
  2020-01-07 16:52 [RFT 00/13] iomap: Constify ioreadX() iomem argument Krzysztof Kozlowski
                   ` (12 preceding siblings ...)
  2020-01-07 16:53 ` [RFT 11/13] net: wireless: rtl818x: " Krzysztof Kozlowski
@ 2020-01-07 16:53 ` " Krzysztof Kozlowski
  2020-01-07 16:53 ` [RFT 13/13] virtio: pci: " Krzysztof Kozlowski
  2020-01-08  8:07 ` [RFT 00/13] iomap: Constify ioreadX() iomem argument Geert Uytterhoeven
  15 siblings, 0 replies; 31+ messages in thread
From: Krzysztof Kozlowski @ 2020-01-07 16:53 UTC (permalink / raw)
  To: Richard Henderson, Ivan Kokshaysky, Matt Turner, Alexey Brodkin,
	Vineet Gupta, James E.J. Bottomley, Helge Deller,
	Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman,
	Yoshinori Sato, Rich Felker, Dave Airlie, David Airlie,
	Daniel Vetter, Ben Skeggs, Mauro Carvalho Chehab, Jiri Slaby,
	Nick Kossifidis, Luis Chamberlain, Kalle Valo, David S. Miller,
	Dave Jiang, Jon Mason, Allen Hubbe, Michael S. Tsirkin,
	Jason Wang, Arnd Bergmann, Andrew Morton, Thomas Gleixner,
	Geert Uytterhoeven, linux-alpha, linux-kernel, linux-snps-arc,
	linux-parisc, linuxppc-dev, linux-sh, dri-devel, nouveau,
	linux-media, linux-wireless, netdev, linux-ntb, virtualization,
	linux-arch
  Cc: Krzysztof Kozlowski

The ioreadX() 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.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
---
 drivers/ntb/hw/intel/ntb_hw_gen1.c  | 2 +-
 drivers/ntb/hw/intel/ntb_hw_gen3.h  | 2 +-
 drivers/ntb/hw/intel/ntb_hw_intel.h | 2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/ntb/hw/intel/ntb_hw_gen1.c b/drivers/ntb/hw/intel/ntb_hw_gen1.c
index bb57ec239029..9202502a9787 100644
--- a/drivers/ntb/hw/intel/ntb_hw_gen1.c
+++ b/drivers/ntb/hw/intel/ntb_hw_gen1.c
@@ -1202,7 +1202,7 @@ int intel_ntb_peer_spad_write(struct ntb_dev *ntb, int pidx, int sidx,
 			       ndev->peer_reg->spad);
 }
 
-static u64 xeon_db_ioread(void __iomem *mmio)
+static u64 xeon_db_ioread(const void __iomem *mmio)
 {
 	return (u64)ioread16(mmio);
 }
diff --git a/drivers/ntb/hw/intel/ntb_hw_gen3.h b/drivers/ntb/hw/intel/ntb_hw_gen3.h
index 75fb86ca27bb..d1455f24ec99 100644
--- a/drivers/ntb/hw/intel/ntb_hw_gen3.h
+++ b/drivers/ntb/hw/intel/ntb_hw_gen3.h
@@ -91,7 +91,7 @@
 #define GEN3_DB_TOTAL_SHIFT		33
 #define GEN3_SPAD_COUNT			16
 
-static inline u64 gen3_db_ioread(void __iomem *mmio)
+static inline u64 gen3_db_ioread(const void __iomem *mmio)
 {
 	return ioread64(mmio);
 }
diff --git a/drivers/ntb/hw/intel/ntb_hw_intel.h b/drivers/ntb/hw/intel/ntb_hw_intel.h
index e071e28bca3f..3c0a5a2da241 100644
--- a/drivers/ntb/hw/intel/ntb_hw_intel.h
+++ b/drivers/ntb/hw/intel/ntb_hw_intel.h
@@ -102,7 +102,7 @@ struct intel_ntb_dev;
 struct intel_ntb_reg {
 	int (*poll_link)(struct intel_ntb_dev *ndev);
 	int (*link_is_up)(struct intel_ntb_dev *ndev);
-	u64 (*db_ioread)(void __iomem *mmio);
+	u64 (*db_ioread)(const void __iomem *mmio);
 	void (*db_iowrite)(u64 db_bits, void __iomem *mmio);
 	unsigned long			ntb_ctl;
 	resource_size_t			db_size;
-- 
2.7.4


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http://lists.infradead.org/mailman/listinfo/linux-snps-arc

^ permalink raw reply	[flat|nested] 31+ messages in thread

* [RFT 13/13] virtio: pci: Constify ioreadX() iomem argument (as in generic implementation)
  2020-01-07 16:52 [RFT 00/13] iomap: Constify ioreadX() iomem argument Krzysztof Kozlowski
                   ` (13 preceding siblings ...)
  2020-01-07 16:53 ` [RFT 12/13] ntb: intel: " Krzysztof Kozlowski
@ 2020-01-07 16:53 ` " Krzysztof Kozlowski
  2020-01-08  8:07 ` [RFT 00/13] iomap: Constify ioreadX() iomem argument Geert Uytterhoeven
  15 siblings, 0 replies; 31+ messages in thread
From: Krzysztof Kozlowski @ 2020-01-07 16:53 UTC (permalink / raw)
  To: Richard Henderson, Ivan Kokshaysky, Matt Turner, Alexey Brodkin,
	Vineet Gupta, James E.J. Bottomley, Helge Deller,
	Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman,
	Yoshinori Sato, Rich Felker, Dave Airlie, David Airlie,
	Daniel Vetter, Ben Skeggs, Mauro Carvalho Chehab, Jiri Slaby,
	Nick Kossifidis, Luis Chamberlain, Kalle Valo, David S. Miller,
	Dave Jiang, Jon Mason, Allen Hubbe, Michael S. Tsirkin,
	Jason Wang, Arnd Bergmann, Andrew Morton, Thomas Gleixner,
	Geert Uytterhoeven, linux-alpha, linux-kernel, linux-snps-arc,
	linux-parisc, linuxppc-dev, linux-sh, dri-devel, nouveau,
	linux-media, linux-wireless, netdev, linux-ntb, virtualization,
	linux-arch
  Cc: Krzysztof Kozlowski

The ioreadX() 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.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
---
 drivers/virtio/virtio_pci_modern.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/virtio/virtio_pci_modern.c b/drivers/virtio/virtio_pci_modern.c
index 7abcc50838b8..fc58db4ab6c3 100644
--- a/drivers/virtio/virtio_pci_modern.c
+++ b/drivers/virtio/virtio_pci_modern.c
@@ -26,16 +26,16 @@
  * method, i.e. 32-bit accesses for 32-bit fields, 16-bit accesses
  * for 16-bit fields and 8-bit accesses for 8-bit fields.
  */
-static inline u8 vp_ioread8(u8 __iomem *addr)
+static inline u8 vp_ioread8(const u8 __iomem *addr)
 {
 	return ioread8(addr);
 }
-static inline u16 vp_ioread16 (__le16 __iomem *addr)
+static inline u16 vp_ioread16 (const __le16 __iomem *addr)
 {
 	return ioread16(addr);
 }
 
-static inline u32 vp_ioread32(__le32 __iomem *addr)
+static inline u32 vp_ioread32(const __le32 __iomem *addr)
 {
 	return ioread32(addr);
 }
-- 
2.7.4


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^ permalink raw reply	[flat|nested] 31+ messages in thread

* Re: [RFT 03/13] sh: Constify ioreadX() iomem argument (as in generic implementation)
  2020-01-07 16:53 ` [RFT 03/13] sh: " Krzysztof Kozlowski
@ 2020-01-07 17:08   ` Arnd Bergmann
  0 siblings, 0 replies; 31+ messages in thread
From: Arnd Bergmann @ 2020-01-07 17:08 UTC (permalink / raw)
  To: Krzysztof Kozlowski
  Cc: Rich Felker, Jiri Slaby, Michael S. Tsirkin, David Airlie,
	Benjamin Herrenschmidt, Jason Wang, dri-devel, virtualization,
	James E.J. Bottomley, Networking, Paul Mackerras, linux-arch,
	Dave Jiang, Yoshinori Sato, Michael Ellerman, Helge Deller,
	Linux-sh list, Alexey Brodkin, Geert Uytterhoeven, Ben Skeggs,
	ML nouveau, Dave Airlie, Matt Turner,
	open list:SYNOPSYS ARC ARCHITECTURE, Nick Kossifidis,
	Allen Hubbe, alpha, Ivan Kokshaysky, Thomas Gleixner,
	Mauro Carvalho Chehab, Kalle Valo, Richard Henderson,
	Parisc List, Vineet Gupta, linux-wireless, linux-kernel,
	Luis Chamberlain, Daniel Vetter, Jon Mason, linux-ntb,
	Andrew Morton, Linux Media Mailing List, linuxppc-dev,
	David S. Miller

On Tue, Jan 7, 2020 at 5:54 PM Krzysztof Kozlowski <krzk@kernel.org> wrote:
>
> The ioreadX() 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.
>
> Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>

The patch looks good, but I think this has to be done together with the powerpc
version and the header that declares the function, for bisectibility.

       Arnd

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^ permalink raw reply	[flat|nested] 31+ messages in thread

* Re: [RFT 06/13] arc: Constify ioreadX() iomem argument (as in generic implementation)
  2020-01-07 16:53 ` [RFT 06/13] arc: " Krzysztof Kozlowski
@ 2020-01-07 17:10   ` Arnd Bergmann
  0 siblings, 0 replies; 31+ messages in thread
From: Arnd Bergmann @ 2020-01-07 17:10 UTC (permalink / raw)
  To: Krzysztof Kozlowski
  Cc: Rich Felker, Jiri Slaby, Michael S. Tsirkin, David Airlie,
	Benjamin Herrenschmidt, Jason Wang, dri-devel, virtualization,
	James E.J. Bottomley, Networking, Paul Mackerras, linux-arch,
	Dave Jiang, Yoshinori Sato, Michael Ellerman, Helge Deller,
	Linux-sh list, Alexey Brodkin, Geert Uytterhoeven, Ben Skeggs,
	ML nouveau, Dave Airlie, Matt Turner,
	open list:SYNOPSYS ARC ARCHITECTURE, Nick Kossifidis,
	Allen Hubbe, alpha, Ivan Kokshaysky, Thomas Gleixner,
	Mauro Carvalho Chehab, Kalle Valo, Richard Henderson,
	Parisc List, Vineet Gupta, linux-wireless, linux-kernel,
	Luis Chamberlain, Daniel Vetter, Jon Mason, linux-ntb,
	Andrew Morton, Linux Media Mailing List, linuxppc-dev,
	David S. Miller

On Tue, Jan 7, 2020 at 5:54 PM Krzysztof Kozlowski <krzk@kernel.org> wrote:
>
> The ioreadX() 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.
>
> Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>

The patch looks correct, but I would not bother here, as it has no
effect on the compiler or its output.

      Arnd

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^ permalink raw reply	[flat|nested] 31+ messages in thread

* Re: [RFT 00/13] iomap: Constify ioreadX() iomem argument
  2020-01-07 16:52 [RFT 00/13] iomap: Constify ioreadX() iomem argument Krzysztof Kozlowski
                   ` (14 preceding siblings ...)
  2020-01-07 16:53 ` [RFT 13/13] virtio: pci: " Krzysztof Kozlowski
@ 2020-01-08  8:07 ` Geert Uytterhoeven
  2020-01-08  8:12   ` Geert Uytterhoeven
  2020-01-08  8:15   ` Krzysztof Kozlowski
  15 siblings, 2 replies; 31+ messages in thread
From: Geert Uytterhoeven @ 2020-01-08  8:07 UTC (permalink / raw)
  To: Krzysztof Kozlowski
  Cc: Rich Felker, Jiri Slaby, Michael S. Tsirkin, David Airlie,
	Benjamin Herrenschmidt, Jason Wang, DRI Development,
	virtualization, James E.J. Bottomley, netdev, Paul Mackerras,
	Linux-Arch, Dave Jiang, Yoshinori Sato, Michael Ellerman,
	Helge Deller, Linux-sh list, Alexey Brodkin, Ben Skeggs, nouveau,
	Dave Airlie, Matt Turner, arcml, Nick Kossifidis, Allen Hubbe,
	Arnd Bergmann, alpha, Ivan Kokshaysky, Thomas Gleixner,
	Mauro Carvalho Chehab, Kalle Valo, Richard Henderson,
	Parisc List, Vineet Gupta, linux-wireless,
	Linux Kernel Mailing List, Luis Chamberlain, Daniel Vetter,
	Jon Mason, linux-ntb, Andrew Morton, Linux Media Mailing List,
	linuxppc-dev, David S. Miller

Hi Krzysztof,

On Tue, Jan 7, 2020 at 5:53 PM Krzysztof Kozlowski <krzk@kernel.org> wrote:
> 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.

Shouldn't all of them take const volatile __iomem pointers?
It seems the "volatile" is missing from all but the implementations in
include/asm-generic/io.h.

> Patchset was really tested on all affected architectures.
> Build testing is in progress - I hope auto-builders will point any issues.
>
>
> Todo
> ====
> Convert also string versions (ioread16_rep() etc) if this aproach looks OK.
>
>
> Merging
> =======
> The first 5 patches - iomap, alpha, sh, parisc and powerpc - should probably go
> via one tree, or even squashed into one.

Yes, they should be squashed, cfr. Arnd's comment.
I also wouldn't bother doing the updates in patches 6-10.

The rest looks good to me.
Thanks a lot!

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

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^ permalink raw reply	[flat|nested] 31+ messages in thread

* Re: [RFT 02/13] alpha: Constify ioreadX() iomem argument (as in generic implementation)
  2020-01-07 16:52 ` [RFT 02/13] alpha: " Krzysztof Kozlowski
@ 2020-01-08  8:10   ` Geert Uytterhoeven
  2020-01-08  9:07     ` Krzysztof Kozlowski
  0 siblings, 1 reply; 31+ messages in thread
From: Geert Uytterhoeven @ 2020-01-08  8:10 UTC (permalink / raw)
  To: Krzysztof Kozlowski
  Cc: Rich Felker, Jiri Slaby, Michael S. Tsirkin, David Airlie,
	Benjamin Herrenschmidt, Jason Wang, DRI Development,
	virtualization, James E.J. Bottomley, netdev, Paul Mackerras,
	Linux-Arch, Dave Jiang, Yoshinori Sato, Michael Ellerman,
	Helge Deller, Linux-sh list, Alexey Brodkin, Ben Skeggs, nouveau,
	Dave Airlie, Matt Turner, arcml, Nick Kossifidis, Allen Hubbe,
	Arnd Bergmann, alpha, Ivan Kokshaysky, Thomas Gleixner,
	Mauro Carvalho Chehab, Kalle Valo, Richard Henderson,
	Parisc List, Vineet Gupta, linux-wireless,
	Linux Kernel Mailing List, Luis Chamberlain, Daniel Vetter,
	Jon Mason, linux-ntb, Andrew Morton, Linux Media Mailing List,
	linuxppc-dev, David S. Miller

Hi Krzysztof,

On Tue, Jan 7, 2020 at 5:53 PM Krzysztof Kozlowski <krzk@kernel.org> wrote:
> The ioreadX() 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.
>
> Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>

> --- a/arch/alpha/include/asm/io.h
> +++ b/arch/alpha/include/asm/io.h
> @@ -151,9 +151,9 @@ static inline void generic_##NAME(TYPE b, QUAL void __iomem *addr)  \
>         alpha_mv.mv_##NAME(b, addr);                                    \
>  }
>
> -REMAP1(unsigned int, ioread8, /**/)
> -REMAP1(unsigned int, ioread16, /**/)
> -REMAP1(unsigned int, ioread32, /**/)
> +REMAP1(unsigned int, ioread8, const)
> +REMAP1(unsigned int, ioread16, const)
> +REMAP1(unsigned int, ioread32, const)

If these would become "const volatile", there would no longer be a need
for the last parameter of the REMAP1() macro.

>  REMAP1(u8, readb, const volatile)
>  REMAP1(u16, readw, const volatile)
>  REMAP1(u32, readl, const volatile)

Same for REMAP2() macro below, for iowrite*().

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

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^ permalink raw reply	[flat|nested] 31+ messages in thread

* Re: [RFT 00/13] iomap: Constify ioreadX() iomem argument
  2020-01-08  8:07 ` [RFT 00/13] iomap: Constify ioreadX() iomem argument Geert Uytterhoeven
@ 2020-01-08  8:12   ` Geert Uytterhoeven
  2020-01-08  8:18     ` Krzysztof Kozlowski
  2020-01-08  8:15   ` Krzysztof Kozlowski
  1 sibling, 1 reply; 31+ messages in thread
From: Geert Uytterhoeven @ 2020-01-08  8:12 UTC (permalink / raw)
  To: Krzysztof Kozlowski
  Cc: Rich Felker, Jiri Slaby, Michael S. Tsirkin, David Airlie,
	Benjamin Herrenschmidt, Jason Wang, DRI Development,
	virtualization, James E.J. Bottomley, netdev, Paul Mackerras,
	Linux-Arch, Dave Jiang, Yoshinori Sato, Michael Ellerman,
	Helge Deller, Linux-sh list, Alexey Brodkin, Ben Skeggs, nouveau,
	Dave Airlie, Matt Turner, arcml, Nick Kossifidis, Allen Hubbe,
	Arnd Bergmann, alpha, Ivan Kokshaysky, Thomas Gleixner,
	Mauro Carvalho Chehab, Kalle Valo, Richard Henderson,
	Parisc List, Vineet Gupta, linux-wireless,
	Linux Kernel Mailing List, Luis Chamberlain, Daniel Vetter,
	Jon Mason, linux-ntb, Andrew Morton, Linux Media Mailing List,
	linuxppc-dev, David S. Miller

Hi Krzysztof,

On Wed, Jan 8, 2020 at 9:07 AM Geert Uytterhoeven <geert@linux-m68k.org> wrote:
> On Tue, Jan 7, 2020 at 5:53 PM Krzysztof Kozlowski <krzk@kernel.org> wrote:
> > 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.
>
> Shouldn't all of them take const volatile __iomem pointers?
> It seems the "volatile" is missing from all but the implementations in
> include/asm-generic/io.h.

As my "volatile" comment applies to iowrite*(), too, probably that should be
done in a separate patch.

Hence with patches 1-5 squashed, and for patches 11-13:
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

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^ permalink raw reply	[flat|nested] 31+ messages in thread

* Re: [RFT 00/13] iomap: Constify ioreadX() iomem argument
  2020-01-08  8:07 ` [RFT 00/13] iomap: Constify ioreadX() iomem argument Geert Uytterhoeven
  2020-01-08  8:12   ` Geert Uytterhoeven
@ 2020-01-08  8:15   ` Krzysztof Kozlowski
  1 sibling, 0 replies; 31+ messages in thread
From: Krzysztof Kozlowski @ 2020-01-08  8:15 UTC (permalink / raw)
  To: Geert Uytterhoeven
  Cc: Rich Felker, Jiri Slaby, Michael S. Tsirkin, David Airlie,
	Benjamin Herrenschmidt, Jason Wang, DRI Development,
	virtualization, James E.J. Bottomley, netdev, Paul Mackerras,
	Linux-Arch, Dave Jiang, Yoshinori Sato, Michael Ellerman,
	Helge Deller, Linux-sh list, Alexey Brodkin, Ben Skeggs, nouveau,
	Dave Airlie, Matt Turner, arcml, Nick Kossifidis, Allen Hubbe,
	Arnd Bergmann, alpha, Ivan Kokshaysky, Thomas Gleixner,
	Mauro Carvalho Chehab, Kalle Valo, Richard Henderson,
	Parisc List, Vineet Gupta, linux-wireless,
	Linux Kernel Mailing List, Luis Chamberlain, Daniel Vetter,
	Jon Mason, linux-ntb, Andrew Morton, Linux Media Mailing List,
	linuxppc-dev, David S. Miller

On Wed, 8 Jan 2020 at 09:08, Geert Uytterhoeven <geert@linux-m68k.org> wrote:
>
> Hi Krzysztof,
>
> On Tue, Jan 7, 2020 at 5:53 PM Krzysztof Kozlowski <krzk@kernel.org> wrote:
> > 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.
>
> Shouldn't all of them take const volatile __iomem pointers?
> It seems the "volatile" is missing from all but the implementations in
> include/asm-generic/io.h.

It's kind of separate issue although I could squash it to limit
redundant changes.

> > Patchset was really tested on all affected architectures.

I just spot an error in my first message. I wanted to say:
"Patchset was NOT really tested on all affected architectures."

Obviously.


> > Build testing is in progress - I hope auto-builders will point any issues.
> >
> >
> > Todo
> > ====
> > Convert also string versions (ioread16_rep() etc) if this aproach looks OK.
> >
> >
> > Merging
> > =======
> > The first 5 patches - iomap, alpha, sh, parisc and powerpc - should probably go
> > via one tree, or even squashed into one.
>
> Yes, they should be squashed, cfr. Arnd's comment.
> I also wouldn't bother doing the updates in patches 6-10.

Indeed, thanks for comments.

Best regards,
Krzysztof

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^ permalink raw reply	[flat|nested] 31+ messages in thread

* Re: [RFT 00/13] iomap: Constify ioreadX() iomem argument
  2020-01-08  8:12   ` Geert Uytterhoeven
@ 2020-01-08  8:18     ` Krzysztof Kozlowski
  2020-01-08  8:35       ` Christophe Leroy
  0 siblings, 1 reply; 31+ messages in thread
From: Krzysztof Kozlowski @ 2020-01-08  8:18 UTC (permalink / raw)
  To: Geert Uytterhoeven
  Cc: Rich Felker, Jiri Slaby, Michael S. Tsirkin, David Airlie,
	Benjamin Herrenschmidt, Jason Wang, DRI Development,
	virtualization, James E.J. Bottomley, netdev, Paul Mackerras,
	Linux-Arch, Dave Jiang, Yoshinori Sato, Michael Ellerman,
	Helge Deller, Linux-sh list, Alexey Brodkin, Ben Skeggs, nouveau,
	Dave Airlie, Matt Turner, arcml, Nick Kossifidis, Allen Hubbe,
	Arnd Bergmann, alpha, Ivan Kokshaysky, Thomas Gleixner,
	Mauro Carvalho Chehab, Kalle Valo, Richard Henderson,
	Parisc List, Vineet Gupta, linux-wireless,
	Linux Kernel Mailing List, Luis Chamberlain, Daniel Vetter,
	Jon Mason, linux-ntb, Andrew Morton, Linux Media Mailing List,
	linuxppc-dev, David S. Miller

On Wed, 8 Jan 2020 at 09:13, Geert Uytterhoeven <geert@linux-m68k.org> wrote:
>
> Hi Krzysztof,
>
> On Wed, Jan 8, 2020 at 9:07 AM Geert Uytterhoeven <geert@linux-m68k.org> wrote:
> > On Tue, Jan 7, 2020 at 5:53 PM Krzysztof Kozlowski <krzk@kernel.org> wrote:
> > > 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.
> >
> > Shouldn't all of them take const volatile __iomem pointers?
> > It seems the "volatile" is missing from all but the implementations in
> > include/asm-generic/io.h.
>
> As my "volatile" comment applies to iowrite*(), too, probably that should be
> done in a separate patch.
>
> Hence with patches 1-5 squashed, and for patches 11-13:
> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>

I'll add to this one also changes to ioreadX_rep() and add another
patch for volatile for reads and writes. I guess your review will be
appreciated once more because of ioreadX_rep()

Thanks,
Krzysztof

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^ permalink raw reply	[flat|nested] 31+ messages in thread

* Re: [RFT 00/13] iomap: Constify ioreadX() iomem argument
  2020-01-08  8:18     ` Krzysztof Kozlowski
@ 2020-01-08  8:35       ` Christophe Leroy
  2020-01-08  8:43         ` Geert Uytterhoeven
  2020-01-08  8:44         ` Arnd Bergmann
  0 siblings, 2 replies; 31+ messages in thread
From: Christophe Leroy @ 2020-01-08  8:35 UTC (permalink / raw)
  To: Krzysztof Kozlowski, Geert Uytterhoeven
  Cc: Rich Felker, Jiri Slaby, Michael S. Tsirkin, David Airlie,
	nouveau, Jason Wang, DRI Development, virtualization,
	James E.J. Bottomley, Paul Mackerras, Linux-Arch, Dave Jiang,
	Yoshinori Sato, Helge Deller, Linux-sh list, Alexey Brodkin,
	Ben Skeggs, Dave Airlie, Matt Turner, arcml, Nick Kossifidis,
	Allen Hubbe, Arnd Bergmann, Jon Mason, Ivan Kokshaysky,
	Thomas Gleixner, Mauro Carvalho Chehab, Kalle Valo,
	Richard Henderson, Parisc List, netdev, linux-wireless,
	Linux Kernel Mailing List, Luis Chamberlain, Vineet Gupta,
	Daniel Vetter, alpha, linux-ntb, Andrew Morton,
	Linux Media Mailing List, linuxppc-dev, David S. Miller



Le 08/01/2020 à 09:18, Krzysztof Kozlowski a écrit :
> On Wed, 8 Jan 2020 at 09:13, Geert Uytterhoeven <geert@linux-m68k.org> wrote:
>>
>> Hi Krzysztof,
>>
>> On Wed, Jan 8, 2020 at 9:07 AM Geert Uytterhoeven <geert@linux-m68k.org> wrote:
>>> On Tue, Jan 7, 2020 at 5:53 PM Krzysztof Kozlowski <krzk@kernel.org> wrote:
>>>> 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.
>>>
>>> Shouldn't all of them take const volatile __iomem pointers?
>>> It seems the "volatile" is missing from all but the implementations in
>>> include/asm-generic/io.h.
>>
>> As my "volatile" comment applies to iowrite*(), too, probably that should be
>> done in a separate patch.
>>
>> Hence with patches 1-5 squashed, and for patches 11-13:
>> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
> 
> I'll add to this one also changes to ioreadX_rep() and add another
> patch for volatile for reads and writes. I guess your review will be
> appreciated once more because of ioreadX_rep()
> 

volatile should really only be used where deemed necessary:

https://www.kernel.org/doc/html/latest/process/volatile-considered-harmful.html

It is said: " ...  accessor functions might use volatile on 
architectures where direct I/O memory access does work. Essentially, 
each accessor call becomes a little critical section on its own and 
ensures that the access happens as expected by the programmer."

Christophe

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^ permalink raw reply	[flat|nested] 31+ messages in thread

* Re: [RFT 00/13] iomap: Constify ioreadX() iomem argument
  2020-01-08  8:35       ` Christophe Leroy
@ 2020-01-08  8:43         ` Geert Uytterhoeven
  2020-01-08  8:48           ` Christophe Leroy
  2020-01-08  8:44         ` Arnd Bergmann
  1 sibling, 1 reply; 31+ messages in thread
From: Geert Uytterhoeven @ 2020-01-08  8:43 UTC (permalink / raw)
  To: Christophe Leroy
  Cc: Rich Felker, Jiri Slaby, Michael S. Tsirkin, David Airlie,
	nouveau, Jason Wang, DRI Development, virtualization,
	James E.J. Bottomley, Paul Mackerras, Linux-Arch, Dave Jiang,
	Yoshinori Sato, Helge Deller, Linux-sh list, Alexey Brodkin,
	Krzysztof Kozlowski, Ben Skeggs, Dave Airlie, Matt Turner, arcml,
	Nick Kossifidis, Allen Hubbe, Arnd Bergmann, Jon Mason,
	Ivan Kokshaysky, Thomas Gleixner, Mauro Carvalho Chehab,
	Kalle Valo, Richard Henderson, Parisc List, netdev,
	linux-wireless, Linux Kernel Mailing List, Luis Chamberlain,
	Vineet Gupta, Daniel Vetter, alpha, linux-ntb, Andrew Morton,
	Linux Media Mailing List, linuxppc-dev, David S. Miller

Hi Christophe,

On Wed, Jan 8, 2020 at 9:35 AM Christophe Leroy <christophe.leroy@c-s.fr> wrote:
> Le 08/01/2020 à 09:18, Krzysztof Kozlowski a écrit :
> > On Wed, 8 Jan 2020 at 09:13, Geert Uytterhoeven <geert@linux-m68k.org> wrote:
> >> On Wed, Jan 8, 2020 at 9:07 AM Geert Uytterhoeven <geert@linux-m68k.org> wrote:
> >>> On Tue, Jan 7, 2020 at 5:53 PM Krzysztof Kozlowski <krzk@kernel.org> wrote:
> >>>> 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.
> >>>
> >>> Shouldn't all of them take const volatile __iomem pointers?
> >>> It seems the "volatile" is missing from all but the implementations in
> >>> include/asm-generic/io.h.
> >>
> >> As my "volatile" comment applies to iowrite*(), too, probably that should be
> >> done in a separate patch.
> >>
> >> Hence with patches 1-5 squashed, and for patches 11-13:
> >> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
> >
> > I'll add to this one also changes to ioreadX_rep() and add another
> > patch for volatile for reads and writes. I guess your review will be
> > appreciated once more because of ioreadX_rep()
>
> volatile should really only be used where deemed necessary:
>
> https://www.kernel.org/doc/html/latest/process/volatile-considered-harmful.html
>
> It is said: " ...  accessor functions might use volatile on
> architectures where direct I/O memory access does work. Essentially,
> each accessor call becomes a little critical section on its own and
> ensures that the access happens as expected by the programmer."

That is exactly the use case here: all above are accessor functions.

Why would ioreadX() not need volatile, while readY() does?

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

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^ permalink raw reply	[flat|nested] 31+ messages in thread

* Re: [RFT 00/13] iomap: Constify ioreadX() iomem argument
  2020-01-08  8:35       ` Christophe Leroy
  2020-01-08  8:43         ` Geert Uytterhoeven
@ 2020-01-08  8:44         ` Arnd Bergmann
  2020-01-08  9:15           ` Krzysztof Kozlowski
  1 sibling, 1 reply; 31+ messages in thread
From: Arnd Bergmann @ 2020-01-08  8:44 UTC (permalink / raw)
  To: Christophe Leroy
  Cc: Rich Felker, Jiri Slaby, Michael S. Tsirkin, David Airlie,
	ML nouveau, Jason Wang, DRI Development, virtualization,
	James E.J. Bottomley, Paul Mackerras, Linux-Arch, Dave Jiang,
	Yoshinori Sato, Helge Deller, Linux-sh list, Alexey Brodkin,
	Krzysztof Kozlowski, Geert Uytterhoeven, Ben Skeggs, Dave Airlie,
	Matt Turner, arcml, Nick Kossifidis, Allen Hubbe, Jon Mason,
	Ivan Kokshaysky, Thomas Gleixner, Mauro Carvalho Chehab,
	Kalle Valo, Richard Henderson, Parisc List, netdev,
	linux-wireless, Linux Kernel Mailing List, Luis Chamberlain,
	Vineet Gupta, Daniel Vetter, alpha, linux-ntb, Andrew Morton,
	Linux Media Mailing List, linuxppc-dev, David S. Miller

On Wed, Jan 8, 2020 at 9:36 AM Christophe Leroy <christophe.leroy@c-s.fr> wrote:
> Le 08/01/2020 à 09:18, Krzysztof Kozlowski a écrit :
> > On Wed, 8 Jan 2020 at 09:13, Geert Uytterhoeven <geert@linux-m68k.org> wrote:
> > I'll add to this one also changes to ioreadX_rep() and add another
> > patch for volatile for reads and writes. I guess your review will be
> > appreciated once more because of ioreadX_rep()
> >
>
> volatile should really only be used where deemed necessary:
>
> https://www.kernel.org/doc/html/latest/process/volatile-considered-harmful.html
>
> It is said: " ...  accessor functions might use volatile on
> architectures where direct I/O memory access does work. Essentially,
> each accessor call becomes a little critical section on its own and
> ensures that the access happens as expected by the programmer."

The I/O accessors are one of the few places in which 'volatile' generally
makes sense, at least for the implementations that do a plain pointer
dereference (probably none of the ones in question here).

In case of readl/writel, this is what we do in asm-generic:

static inline u32 __raw_readl(const volatile void __iomem *addr)
{
        return *(const volatile u32 __force *)addr;
}

The __force-cast that removes the __iomem here also means that
the 'volatile' keyword could be dropped from the argument list,
as it has no real effect any more, but then there are a few drivers
that mark their iomem pointers as either 'volatile void __iomem*' or
(worse) 'volatile void *', so we keep it in the argument list to not
add warnings for those drivers.

It may be time to change these drivers to not use volatile for __iomem
pointers, but that seems out of scope for what Krzysztof is trying
to do. Ideally we would be consistent here though, either using volatile
all the time or never.

        Arnd

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^ permalink raw reply	[flat|nested] 31+ messages in thread

* Re: [RFT 00/13] iomap: Constify ioreadX() iomem argument
  2020-01-08  8:43         ` Geert Uytterhoeven
@ 2020-01-08  8:48           ` Christophe Leroy
  2020-01-08 17:39             ` David Laight
  0 siblings, 1 reply; 31+ messages in thread
From: Christophe Leroy @ 2020-01-08  8:48 UTC (permalink / raw)
  To: Geert Uytterhoeven
  Cc: Rich Felker, Jiri Slaby, Michael S. Tsirkin, David Airlie,
	nouveau, Jason Wang, DRI Development, virtualization,
	James E.J. Bottomley, Paul Mackerras, Linux-Arch, Dave Jiang,
	Yoshinori Sato, Helge Deller, Linux-sh list, Alexey Brodkin,
	Krzysztof Kozlowski, Ben Skeggs, Dave Airlie, Matt Turner, arcml,
	Nick Kossifidis, Allen Hubbe, Arnd Bergmann, Jon Mason,
	Ivan Kokshaysky, Thomas Gleixner, Mauro Carvalho Chehab,
	Kalle Valo, Richard Henderson, Parisc List, netdev,
	linux-wireless, Linux Kernel Mailing List, Luis Chamberlain,
	Vineet Gupta, Daniel Vetter, alpha, linux-ntb, Andrew Morton,
	Linux Media Mailing List, linuxppc-dev, David S. Miller

Hi Geert,

Le 08/01/2020 à 09:43, Geert Uytterhoeven a écrit :
> Hi Christophe,
> 
> On Wed, Jan 8, 2020 at 9:35 AM Christophe Leroy <christophe.leroy@c-s.fr> wrote:
>> Le 08/01/2020 à 09:18, Krzysztof Kozlowski a écrit :
>>> On Wed, 8 Jan 2020 at 09:13, Geert Uytterhoeven <geert@linux-m68k.org> wrote:
>>>> On Wed, Jan 8, 2020 at 9:07 AM Geert Uytterhoeven <geert@linux-m68k.org> wrote:
>>>>> On Tue, Jan 7, 2020 at 5:53 PM Krzysztof Kozlowski <krzk@kernel.org> wrote:
>>>>>> 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.
>>>>>
>>>>> Shouldn't all of them take const volatile __iomem pointers?
>>>>> It seems the "volatile" is missing from all but the implementations in
>>>>> include/asm-generic/io.h.
>>>>
>>>> As my "volatile" comment applies to iowrite*(), too, probably that should be
>>>> done in a separate patch.
>>>>
>>>> Hence with patches 1-5 squashed, and for patches 11-13:
>>>> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
>>>
>>> I'll add to this one also changes to ioreadX_rep() and add another
>>> patch for volatile for reads and writes. I guess your review will be
>>> appreciated once more because of ioreadX_rep()
>>
>> volatile should really only be used where deemed necessary:
>>
>> https://www.kernel.org/doc/html/latest/process/volatile-considered-harmful.html
>>
>> It is said: " ...  accessor functions might use volatile on
>> architectures where direct I/O memory access does work. Essentially,
>> each accessor call becomes a little critical section on its own and
>> ensures that the access happens as expected by the programmer."
> 
> That is exactly the use case here: all above are accessor functions.
> 
> Why would ioreadX() not need volatile, while readY() does?
> 

My point was: it might be necessary for some arches and not for others.

And as pointed by Arnd, the volatile is really only necessary for the 
dereference itself, should the arch use dereferencing.

So I guess the best would be to go in the other direction: remove 
volatile keyword wherever possible instead of adding it where it is not 
needed.

Christophe

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^ permalink raw reply	[flat|nested] 31+ messages in thread

* Re: [RFT 02/13] alpha: Constify ioreadX() iomem argument (as in generic implementation)
  2020-01-08  8:10   ` Geert Uytterhoeven
@ 2020-01-08  9:07     ` Krzysztof Kozlowski
  0 siblings, 0 replies; 31+ messages in thread
From: Krzysztof Kozlowski @ 2020-01-08  9:07 UTC (permalink / raw)
  To: Geert Uytterhoeven
  Cc: Rich Felker, Jiri Slaby, Michael S. Tsirkin, David Airlie,
	Benjamin Herrenschmidt, Jason Wang, DRI Development,
	virtualization, James E.J. Bottomley, netdev, Paul Mackerras,
	Linux-Arch, Dave Jiang, Yoshinori Sato, Michael Ellerman,
	Helge Deller, Linux-sh list, Alexey Brodkin, Ben Skeggs, nouveau,
	Dave Airlie, Matt Turner, arcml, Nick Kossifidis, Allen Hubbe,
	Arnd Bergmann, alpha, Ivan Kokshaysky, Thomas Gleixner,
	Mauro Carvalho Chehab, Kalle Valo, Richard Henderson,
	Parisc List, Vineet Gupta, linux-wireless,
	Linux Kernel Mailing List, Luis Chamberlain, Daniel Vetter,
	Jon Mason, linux-ntb, Andrew Morton, Linux Media Mailing List,
	linuxppc-dev, David S. Miller

On Wed, Jan 08, 2020 at 09:10:06AM +0100, Geert Uytterhoeven wrote:
> Hi Krzysztof,
> 
> On Tue, Jan 7, 2020 at 5:53 PM Krzysztof Kozlowski <krzk@kernel.org> wrote:
> > The ioreadX() 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.
> >
> > Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
> 
> > --- a/arch/alpha/include/asm/io.h
> > +++ b/arch/alpha/include/asm/io.h
> > @@ -151,9 +151,9 @@ static inline void generic_##NAME(TYPE b, QUAL void __iomem *addr)  \
> >         alpha_mv.mv_##NAME(b, addr);                                    \
> >  }
> >
> > -REMAP1(unsigned int, ioread8, /**/)
> > -REMAP1(unsigned int, ioread16, /**/)
> > -REMAP1(unsigned int, ioread32, /**/)
> > +REMAP1(unsigned int, ioread8, const)
> > +REMAP1(unsigned int, ioread16, const)
> > +REMAP1(unsigned int, ioread32, const)
> 
> If these would become "const volatile", there would no longer be a need
> for the last parameter of the REMAP1() macro.
> 
> >  REMAP1(u8, readb, const volatile)
> >  REMAP1(u16, readw, const volatile)
> >  REMAP1(u32, readl, const volatile)
> 
> Same for REMAP2() macro below, for iowrite*().

Good point, thanks!

Best regards,
Krzysztof


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^ permalink raw reply	[flat|nested] 31+ messages in thread

* Re: [RFT 00/13] iomap: Constify ioreadX() iomem argument
  2020-01-08  8:44         ` Arnd Bergmann
@ 2020-01-08  9:15           ` Krzysztof Kozlowski
  2020-01-08 11:55             ` Arnd Bergmann
  0 siblings, 1 reply; 31+ messages in thread
From: Krzysztof Kozlowski @ 2020-01-08  9:15 UTC (permalink / raw)
  To: Arnd Bergmann
  Cc: Rich Felker, Jiri Slaby, Michael S. Tsirkin, David Airlie,
	ML nouveau, Jason Wang, DRI Development, virtualization,
	James E.J. Bottomley, Paul Mackerras, Linux-Arch, Dave Jiang,
	Yoshinori Sato, Helge Deller, Linux-sh list, Alexey Brodkin,
	Geert Uytterhoeven, Ben Skeggs, Dave Airlie, Matt Turner, arcml,
	Nick Kossifidis, Allen Hubbe, Jon Mason, Ivan Kokshaysky,
	Thomas Gleixner, Mauro Carvalho Chehab, Kalle Valo,
	Richard Henderson, Christophe Leroy, Parisc List, netdev,
	linux-wireless, Linux Kernel Mailing List, Luis Chamberlain,
	Vineet Gupta, Daniel Vetter, alpha, linux-ntb, Andrew Morton,
	Linux Media Mailing List, linuxppc-dev, David S. Miller

On Wed, Jan 08, 2020 at 09:44:36AM +0100, Arnd Bergmann wrote:
> On Wed, Jan 8, 2020 at 9:36 AM Christophe Leroy <christophe.leroy@c-s.fr> wrote:
> > Le 08/01/2020 à 09:18, Krzysztof Kozlowski a écrit :
> > > On Wed, 8 Jan 2020 at 09:13, Geert Uytterhoeven <geert@linux-m68k.org> wrote:
> > > I'll add to this one also changes to ioreadX_rep() and add another
> > > patch for volatile for reads and writes. I guess your review will be
> > > appreciated once more because of ioreadX_rep()
> > >
> >
> > volatile should really only be used where deemed necessary:
> >
> > https://www.kernel.org/doc/html/latest/process/volatile-considered-harmful.html
> >
> > It is said: " ...  accessor functions might use volatile on
> > architectures where direct I/O memory access does work. Essentially,
> > each accessor call becomes a little critical section on its own and
> > ensures that the access happens as expected by the programmer."
> 
> The I/O accessors are one of the few places in which 'volatile' generally
> makes sense, at least for the implementations that do a plain pointer
> dereference (probably none of the ones in question here).
> 
> In case of readl/writel, this is what we do in asm-generic:
> 
> static inline u32 __raw_readl(const volatile void __iomem *addr)
> {
>         return *(const volatile u32 __force *)addr;
> }

SuperH is another example:
1. ioread8_rep(void __iomem *addr, void *dst, unsigned long count)
   calls mmio_insb()

2. static inline void mmio_insb(void __iomem *addr, u8 *dst, int count)
   calls __raw_readb()

3. #define __raw_readb(a)          (__chk_io_ptr(a), *(volatile u8  __force *)(a))

Even if interface was not marked as volatile, in fact its implementation
was casting to volatile.

> The __force-cast that removes the __iomem here also means that
> the 'volatile' keyword could be dropped from the argument list,
> as it has no real effect any more, but then there are a few drivers
> that mark their iomem pointers as either 'volatile void __iomem*' or
> (worse) 'volatile void *', so we keep it in the argument list to not
> add warnings for those drivers.
> 
> It may be time to change these drivers to not use volatile for __iomem
> pointers, but that seems out of scope for what Krzysztof is trying
> to do. Ideally we would be consistent here though, either using volatile
> all the time or never.

Indeed. I guess there are no objections around const so let me send v2
for const only.

Best regards,
Krzysztof


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^ permalink raw reply	[flat|nested] 31+ messages in thread

* Re: [RFT 00/13] iomap: Constify ioreadX() iomem argument
  2020-01-08  9:15           ` Krzysztof Kozlowski
@ 2020-01-08 11:55             ` Arnd Bergmann
  0 siblings, 0 replies; 31+ messages in thread
From: Arnd Bergmann @ 2020-01-08 11:55 UTC (permalink / raw)
  To: Krzysztof Kozlowski
  Cc: Rich Felker, Jiri Slaby, Michael S. Tsirkin, David Airlie,
	ML nouveau, Jason Wang, DRI Development, virtualization,
	James E.J. Bottomley, Paul Mackerras, Linux-Arch, Dave Jiang,
	Yoshinori Sato, Helge Deller, Linux-sh list, Alexey Brodkin,
	Geert Uytterhoeven, Ben Skeggs, Dave Airlie, Matt Turner, arcml,
	Nick Kossifidis, Allen Hubbe, Jon Mason, Ivan Kokshaysky,
	Thomas Gleixner, Mauro Carvalho Chehab, Kalle Valo,
	Richard Henderson, Christophe Leroy, Parisc List, netdev,
	linux-wireless, Linux Kernel Mailing List, Luis Chamberlain,
	Vineet Gupta, Daniel Vetter, alpha, linux-ntb, Andrew Morton,
	Linux Media Mailing List, linuxppc-dev, David S. Miller

On Wed, Jan 8, 2020 at 10:15 AM Krzysztof Kozlowski <krzk@kernel.org> wrote:

> > The __force-cast that removes the __iomem here also means that
> > the 'volatile' keyword could be dropped from the argument list,
> > as it has no real effect any more, but then there are a few drivers
> > that mark their iomem pointers as either 'volatile void __iomem*' or
> > (worse) 'volatile void *', so we keep it in the argument list to not
> > add warnings for those drivers.
> >
> > It may be time to change these drivers to not use volatile for __iomem
> > pointers, but that seems out of scope for what Krzysztof is trying
> > to do. Ideally we would be consistent here though, either using volatile
> > all the time or never.
>
> Indeed. I guess there are no objections around const so let me send v2
> for const only.

Ok, sounds good. Maybe mention in the changelog then that the
'volatile' in the interface is intentionally left out, and that only users
of readl/writel still have it to deal with existing drivers.

    Arnd

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^ permalink raw reply	[flat|nested] 31+ messages in thread

* RE: [RFT 00/13] iomap: Constify ioreadX() iomem argument
  2020-01-08  8:48           ` Christophe Leroy
@ 2020-01-08 17:39             ` David Laight
  0 siblings, 0 replies; 31+ messages in thread
From: David Laight @ 2020-01-08 17:39 UTC (permalink / raw)
  To: Christophe Leroy, Geert Uytterhoeven
  Cc: Rich Felker, Jiri Slaby, Michael S. Tsirkin, David Airlie,
	nouveau, Jason Wang, DRI Development, virtualization,
	James E.J. Bottomley, Paul Mackerras, Linux-Arch, Dave Jiang,
	Yoshinori Sato, Helge Deller, Linux-sh list, Alexey Brodkin,
	Krzysztof Kozlowski, Ben Skeggs, Dave Airlie, Matt Turner, arcml,
	Nick Kossifidis, Allen Hubbe, Arnd Bergmann, Jon Mason,
	Ivan Kokshaysky, Thomas Gleixner, Mauro Carvalho Chehab,
	Kalle Valo, Richard Henderson, Parisc List, netdev,
	linux-wireless, Linux Kernel Mailing List, Luis Chamberlain,
	Vineet Gupta, Daniel Vetter, alpha, linux-ntb, Andrew Morton,
	Linux Media Mailing List, linuxppc-dev, David S. Miller

From: Christophe Leroy
> Sent: 08 January 2020 08:49
...
> And as pointed by Arnd, the volatile is really only necessary for the
> dereference itself, should the arch use dereferencing.

I've had trouble with some versions of gcc and reading of 'volatile unsigned char *'.
It tended to follow the memory read with an extra mask with 0xff.
(I suspect that internally the value landed into a temporary 'int' variable.)

I got better code using memory barriers.
So putting an asm barrier for the exact location of the memory read
either side of the read should have the desired effect without adding
extra instructions.
(You might think 'volatile' would mean that - but it doesn't.)

	David

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^ permalink raw reply	[flat|nested] 31+ messages in thread

end of thread, back to index

Thread overview: 31+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-01-07 16:52 [RFT 00/13] iomap: Constify ioreadX() iomem argument Krzysztof Kozlowski
2020-01-07 16:52 ` [RFT 01/13] iomap: Constify ioreadX() iomem argument (as in generic implementation) Krzysztof Kozlowski
2020-01-07 16:52 ` [RFT 02/13] alpha: " Krzysztof Kozlowski
2020-01-08  8:10   ` Geert Uytterhoeven
2020-01-08  9:07     ` Krzysztof Kozlowski
2020-01-07 16:53 ` [RFT 02/13] sh: " Krzysztof Kozlowski
2020-01-07 16:53 ` [RFT 03/13] alpha: " Krzysztof Kozlowski
2020-01-07 16:53 ` [RFT 03/13] sh: " Krzysztof Kozlowski
2020-01-07 17:08   ` Arnd Bergmann
2020-01-07 16:53 ` [RFT 04/13] parisc: " Krzysztof Kozlowski
2020-01-07 16:53 ` [RFT 05/13] powerpc: " Krzysztof Kozlowski
2020-01-07 16:53 ` [RFT 06/13] arc: " Krzysztof Kozlowski
2020-01-07 17:10   ` Arnd Bergmann
2020-01-07 16:53 ` [RFT 07/13] drm/mgag200: " Krzysztof Kozlowski
2020-01-07 16:53 ` [RFT 08/13] drm/nouveau: " Krzysztof Kozlowski
2020-01-07 16:53 ` [RFT 09/13] media: fsl-viu: " Krzysztof Kozlowski
2020-01-07 16:53 ` [RFT 10/13] net: wireless: ath5k: " Krzysztof Kozlowski
2020-01-07 16:53 ` [RFT 11/13] net: wireless: rtl818x: " Krzysztof Kozlowski
2020-01-07 16:53 ` [RFT 12/13] ntb: intel: " Krzysztof Kozlowski
2020-01-07 16:53 ` [RFT 13/13] virtio: pci: " Krzysztof Kozlowski
2020-01-08  8:07 ` [RFT 00/13] iomap: Constify ioreadX() iomem argument Geert Uytterhoeven
2020-01-08  8:12   ` Geert Uytterhoeven
2020-01-08  8:18     ` Krzysztof Kozlowski
2020-01-08  8:35       ` Christophe Leroy
2020-01-08  8:43         ` Geert Uytterhoeven
2020-01-08  8:48           ` Christophe Leroy
2020-01-08 17:39             ` David Laight
2020-01-08  8:44         ` Arnd Bergmann
2020-01-08  9:15           ` Krzysztof Kozlowski
2020-01-08 11:55             ` Arnd Bergmann
2020-01-08  8:15   ` Krzysztof Kozlowski

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