[PATCH v2 07/20] include: add linux/io.h with strict prototypes

Ahmad Fatoum
2023-11-22T17:31:41Z

Kernel code uses <linux/io.h> instead of <io.h>, which defines readl and
friends as functions with type checks instead of macros that just cast
everything to pointers. Let's provide <linux/io.h> to ease porting as
well and have it have the same semantics.

Eventually, we should be able to get switch <io.h> to include
<linux/io.h> once all in-tree users are migrated.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
---
v1 -> v2:
- unchanged
---
include/asm-generic/io.h | 217 +++++++++++++++++++++++++++++++++++++--
include/linux/io.h | 9 ++
2 files changed, 218 insertions(+), 8 deletions(-)
create mode 100644 include/linux/io.h

diff --git a/include/asm-generic/io.h b/include/asm-generic/io.h
index b118979ed1df..123ad5488ffc 100644
--- a/include/asm-generic/io.h
+++ b/include/asm-generic/io.h
@@ -13,23 +13,224 @@

#include <linux/string.h> /* for memset() and memcpy() */
#include <linux/compiler.h>
+#include <linux/instruction_pointer.h>
#include <linux/types.h>
#include <asm/byteorder.h>
+
+#ifndef __LINUX_IO_STRICT_PROTOTYPES__
#include <asm-generic/io-typeconfused.h>
+#endif
+
+#define __io_br() barrier()
+#define __io_ar(v) barrier()
+#define __io_bw() barrier()
+#define __io_pbw() __io_bw()
+#define __io_paw() __io_aw()
+#define __io_aw() do { } while (0)
+#define __io_pbr() __io_br()
+#define __io_par(v) __io_ar(v)
+
+static inline void log_write_mmio(u64 val, u8 width, volatile void __iomem *addr,
+ unsigned long caller_addr, unsigned long caller_addr0) {}
+static inline void log_post_write_mmio(u64 val, u8 width, volatile void __iomem *addr,
+ unsigned long caller_addr, unsigned long caller_addr0) {}
+static inline void log_read_mmio(u8 width, const volatile void __iomem *addr,
+ unsigned long caller_addr, unsigned long caller_addr0) {}
+static inline void log_post_read_mmio(u64 val, u8 width, const volatile void __iomem *addr,
+ unsigned long caller_addr, unsigned long caller_addr0) {}
+
+/*
+ * __raw_{read,write}{b,w,l,q}() access memory in native endianness.
+ *
+ * On some architectures memory mapped IO needs to be accessed differently.
+ * On the simple architectures, we just read/write the memory location
+ * directly.
+ */
+
+#ifndef __raw_readb
+#define __raw_readb __raw_readb
+static inline u8 __raw_readb(const volatile void __iomem *addr)
+{
+ return *(const volatile u8 __force *)addr;
+}
+#endif
+
+#ifndef __raw_readw
+#define __raw_readw __raw_readw
+static inline u16 __raw_readw(const volatile void __iomem *addr)
+{
+ return *(const volatile u16 __force *)addr;
+}
+#endif
+
+#ifndef __raw_readl
+#define __raw_readl __raw_readl
+static inline u32 __raw_readl(const volatile void __iomem *addr)
+{
+ return *(const volatile u32 __force *)addr;
+}
+#endif

#ifdef CONFIG_64BIT
+#ifndef __raw_readq
+#define __raw_readq __raw_readq
static inline u64 __raw_readq(const volatile void __iomem *addr)
{
- return *(const volatile u64 __force *) addr;
+ return *(const volatile u64 __force *)addr;
}
-#define readq(addr) __le64_to_cpu(__raw_readq(addr))
-
-static inline void __raw_writeq(u64 b, volatile void __iomem *addr)
-{
- *(volatile u64 __force *) addr = b;
-}
-#define writeq(b,addr) __raw_writeq(__cpu_to_le64(b),addr)
#endif
+#endif /* CONFIG_64BIT */
+
+#ifndef __raw_writeb
+#define __raw_writeb __raw_writeb
+static inline void __raw_writeb(u8 value, volatile void __iomem *addr)
+{
+ *(volatile u8 __force *)addr = value;
+}
+#endif
+
+#ifndef __raw_writew
+#define __raw_writew __raw_writew
+static inline void __raw_writew(u16 value, volatile void __iomem *addr)
+{
+ *(volatile u16 __force *)addr = value;
+}
+#endif
+
+#ifndef __raw_writel
+#define __raw_writel __raw_writel
+static inline void __raw_writel(u32 value, volatile void __iomem *addr)
+{
+ *(volatile u32 __force *)addr = value;
+}
+#endif
+
+#ifdef CONFIG_64BIT
+#ifndef __raw_writeq
+#define __raw_writeq __raw_writeq
+static inline void __raw_writeq(u64 value, volatile void __iomem *addr)
+{
+ *(volatile u64 __force *)addr = value;
+}
+#endif
+#endif /* CONFIG_64BIT */
+
+/*
+ * {read,write}{b,w,l,q}() access little endian memory and return result in
+ * native endianness.
+ */
+
+#ifndef readb
+#define readb readb
+static inline u8 readb(const volatile void __iomem *addr)
+{
+ u8 val;
+
+ log_read_mmio(8, addr, _THIS_IP_, _RET_IP_);
+ __io_br();
+ val = __raw_readb(addr);
+ __io_ar(val);
+ log_post_read_mmio(val, 8, addr, _THIS_IP_, _RET_IP_);
+ return val;
+}
+#endif
+
+#ifndef readw
+#define readw readw
+static inline u16 readw(const volatile void __iomem *addr)
+{
+ u16 val;
+
+ log_read_mmio(16, addr, _THIS_IP_, _RET_IP_);
+ __io_br();
+ val = __le16_to_cpu((__le16 __force)__raw_readw(addr));
+ __io_ar(val);
+ log_post_read_mmio(val, 16, addr, _THIS_IP_, _RET_IP_);
+ return val;
+}
+#endif
+
+#ifndef readl
+#define readl readl
+static inline u32 readl(const volatile void __iomem *addr)
+{
+ u32 val;
+
+ log_read_mmio(32, addr, _THIS_IP_, _RET_IP_);
+ __io_br();
+ val = __le32_to_cpu((__le32 __force)__raw_readl(addr));
+ __io_ar(val);
+ log_post_read_mmio(val, 32, addr, _THIS_IP_, _RET_IP_);
+ return val;
+}
+#endif
+
+#ifdef CONFIG_64BIT
+#ifndef readq
+#define readq readq
+static inline u64 readq(const volatile void __iomem *addr)
+{
+ u64 val;
+
+ log_read_mmio(64, addr, _THIS_IP_, _RET_IP_);
+ __io_br();
+ val = __le64_to_cpu((__le64 __force)__raw_readq(addr));
+ __io_ar(val);
+ log_post_read_mmio(val, 64, addr, _THIS_IP_, _RET_IP_);
+ return val;
+}
+#endif
+#endif /* CONFIG_64BIT */
+
+#ifndef writeb
+#define writeb writeb
+static inline void writeb(u8 value, volatile void __iomem *addr)
+{
+ log_write_mmio(value, 8, addr, _THIS_IP_, _RET_IP_);
+ __io_bw();
+ __raw_writeb(value, addr);
+ __io_aw();
+ log_post_write_mmio(value, 8, addr, _THIS_IP_, _RET_IP_);
+}
+#endif
+
+#ifndef writew
+#define writew writew
+static inline void writew(u16 value, volatile void __iomem *addr)
+{
+ log_write_mmio(value, 16, addr, _THIS_IP_, _RET_IP_);
+ __io_bw();
+ __raw_writew((u16 __force)cpu_to_le16(value), addr);
+ __io_aw();
+ log_post_write_mmio(value, 16, addr, _THIS_IP_, _RET_IP_);
+}
+#endif
+
+#ifndef writel
+#define writel writel
+static inline void writel(u32 value, volatile void __iomem *addr)
+{
+ log_write_mmio(value, 32, addr, _THIS_IP_, _RET_IP_);
+ __io_bw();
+ __raw_writel((u32 __force)__cpu_to_le32(value), addr);
+ __io_aw();
+ log_post_write_mmio(value, 32, addr, _THIS_IP_, _RET_IP_);
+}
+#endif
+
+#ifdef CONFIG_64BIT
+#ifndef writeq
+#define writeq writeq
+static inline void writeq(u64 value, volatile void __iomem *addr)
+{
+ log_write_mmio(value, 64, addr, _THIS_IP_, _RET_IP_);
+ __io_bw();
+ __raw_writeq((u64 __force)__cpu_to_le64(value), addr);
+ __io_aw();
+ log_post_write_mmio(value, 64, addr, _THIS_IP_, _RET_IP_);
+}
+#endif
+#endif /* CONFIG_64BIT */

#ifndef PCI_IOBASE
#define PCI_IOBASE ((void __iomem *)RELOC_HIDE((void *)0, 0))
diff --git a/include/linux/io.h b/include/linux/io.h
new file mode 100644
index 000000000000..9119e4e629d7
--- /dev/null
+++ b/include/linux/io.h
@@ -0,0 +1,9 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef _LINUX_IO_H
+#define _LINUX_IO_H
+
+#define __LINUX_IO_STRICT_PROTOTYPES__
+#include <asm/io.h>
+
+#endif
--
2.39.2