tools headers: Import asm-generic MMIO helpers

Import the asm-generic MMIO helper functions from the kernel headers
into tools/include/. The top-level include is <linux/io.h> which then
includes the arch-specific <asm/io.h>, which then includes
<asm-generic/io.h>. This layout is chosen to match the kernel header
layout and to appease checkpatch.pl (which warns against including
<asm/io.h> or <asm-generic/io.h> directly).

Changes made when importing:

- Add missing includes at the top.
- Stub out mmiowb_set_pending().
- Stub out _THIS_IP_.
- Stub out log_*_mmio() calls.
- Drop the CONFIG_64BIT checks, since tools/include/linux/types.h
always defines u64.

Acked-by: Shuah Khan <[e-mail]>
Signed-off-by: David Matlack <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Alex Williamson <[e-mail]>

tools/include/asm-generic/io.h

···
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _TOOLS_ASM_GENERIC_IO_H
+#define _TOOLS_ASM_GENERIC_IO_H
+
+#include <asm/barrier.h>
+#include <asm/byteorder.h>
+
+#include <linux/compiler.h>
+#include <linux/kernel.h>
+#include <linux/types.h>
+
+#ifndef mmiowb_set_pending
+#define mmiowb_set_pending() do { } while (0)
+#endif
+
+#ifndef __io_br
+#define __io_br()      barrier()
+#endif
+
+/* prevent prefetching of coherent DMA data ahead of a dma-complete */
+#ifndef __io_ar
+#ifdef rmb
+#define __io_ar(v)      rmb()
+#else
+#define __io_ar(v)      barrier()
+#endif
+#endif
+
+/* flush writes to coherent DMA data before possibly triggering a DMA read */
+#ifndef __io_bw
+#ifdef wmb
+#define __io_bw()      wmb()
+#else
+#define __io_bw()      barrier()
+#endif
+#endif
+
+/* serialize device access against a spin_unlock, usually handled there. */
+#ifndef __io_aw
+#define __io_aw()      mmiowb_set_pending()
+#endif
+
+#ifndef __io_pbw
+#define __io_pbw()     __io_bw()
+#endif
+
+#ifndef __io_paw
+#define __io_paw()     __io_aw()
+#endif
+
+#ifndef __io_pbr
+#define __io_pbr()     __io_br()
+#endif
+
+#ifndef __io_par
+#define __io_par(v)     __io_ar(v)
+#endif
+
+#ifndef _THIS_IP_
+#define _THIS_IP_ 0
+#endif
+
+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
+
+#ifndef __raw_readq
+#define __raw_readq __raw_readq
+static inline u64 __raw_readq(const volatile void __iomem *addr)
+{
+	return *(const volatile u64 __force *)addr;
+}
+#endif
+
+#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
+
+#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
+
+/*
+ * {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
+
+#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
+
+#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
+
+#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
+
+/*
+ * {read,write}{b,w,l,q}_relaxed() are like the regular version, but
+ * are not guaranteed to provide ordering against spinlocks or memory
+ * accesses.
+ */
+#ifndef readb_relaxed
+#define readb_relaxed readb_relaxed
+static inline u8 readb_relaxed(const volatile void __iomem *addr)
+{
+	u8 val;
+
+	log_read_mmio(8, addr, _THIS_IP_, _RET_IP_);
+	val = __raw_readb(addr);
+	log_post_read_mmio(val, 8, addr, _THIS_IP_, _RET_IP_);
+	return val;
+}
+#endif
+
+#ifndef readw_relaxed
+#define readw_relaxed readw_relaxed
+static inline u16 readw_relaxed(const volatile void __iomem *addr)
+{
+	u16 val;
+
+	log_read_mmio(16, addr, _THIS_IP_, _RET_IP_);
+	val = __le16_to_cpu((__le16 __force)__raw_readw(addr));
+	log_post_read_mmio(val, 16, addr, _THIS_IP_, _RET_IP_);
+	return val;
+}
+#endif
+
+#ifndef readl_relaxed
+#define readl_relaxed readl_relaxed
+static inline u32 readl_relaxed(const volatile void __iomem *addr)
+{
+	u32 val;
+
+	log_read_mmio(32, addr, _THIS_IP_, _RET_IP_);
+	val = __le32_to_cpu((__le32 __force)__raw_readl(addr));
+	log_post_read_mmio(val, 32, addr, _THIS_IP_, _RET_IP_);
+	return val;
+}
+#endif
+
+#if defined(readq) && !defined(readq_relaxed)
+#define readq_relaxed readq_relaxed
+static inline u64 readq_relaxed(const volatile void __iomem *addr)
+{
+	u64 val;
+
+	log_read_mmio(64, addr, _THIS_IP_, _RET_IP_);
+	val = __le64_to_cpu((__le64 __force)__raw_readq(addr));
+	log_post_read_mmio(val, 64, addr, _THIS_IP_, _RET_IP_);
+	return val;
+}
+#endif
+
+#ifndef writeb_relaxed
+#define writeb_relaxed writeb_relaxed
+static inline void writeb_relaxed(u8 value, volatile void __iomem *addr)
+{
+	log_write_mmio(value, 8, addr, _THIS_IP_, _RET_IP_);
+	__raw_writeb(value, addr);
+	log_post_write_mmio(value, 8, addr, _THIS_IP_, _RET_IP_);
+}
+#endif
+
+#ifndef writew_relaxed
+#define writew_relaxed writew_relaxed
+static inline void writew_relaxed(u16 value, volatile void __iomem *addr)
+{
+	log_write_mmio(value, 16, addr, _THIS_IP_, _RET_IP_);
+	__raw_writew((u16 __force)cpu_to_le16(value), addr);
+	log_post_write_mmio(value, 16, addr, _THIS_IP_, _RET_IP_);
+}
+#endif
+
+#ifndef writel_relaxed
+#define writel_relaxed writel_relaxed
+static inline void writel_relaxed(u32 value, volatile void __iomem *addr)
+{
+	log_write_mmio(value, 32, addr, _THIS_IP_, _RET_IP_);
+	__raw_writel((u32 __force)__cpu_to_le32(value), addr);
+	log_post_write_mmio(value, 32, addr, _THIS_IP_, _RET_IP_);
+}
+#endif
+
+#if defined(writeq) && !defined(writeq_relaxed)
+#define writeq_relaxed writeq_relaxed
+static inline void writeq_relaxed(u64 value, volatile void __iomem *addr)
+{
+	log_write_mmio(value, 64, addr, _THIS_IP_, _RET_IP_);
+	__raw_writeq((u64 __force)__cpu_to_le64(value), addr);
+	log_post_write_mmio(value, 64, addr, _THIS_IP_, _RET_IP_);
+}
+#endif
+
+/*
+ * {read,write}s{b,w,l,q}() repeatedly access the same memory address in
+ * native endianness in 8-, 16-, 32- or 64-bit chunks (@count times).
+ */
+#ifndef readsb
+#define readsb readsb
+static inline void readsb(const volatile void __iomem *addr, void *buffer,
+			  unsigned int count)
+{
+	if (count) {
+		u8 *buf = buffer;
+
+		do {
+			u8 x = __raw_readb(addr);
+			*buf++ = x;
+		} while (--count);
+	}
+}
+#endif
+
+#ifndef readsw
+#define readsw readsw
+static inline void readsw(const volatile void __iomem *addr, void *buffer,
+			  unsigned int count)
+{
+	if (count) {
+		u16 *buf = buffer;
+
+		do {
+			u16 x = __raw_readw(addr);
+			*buf++ = x;
+		} while (--count);
+	}
+}
+#endif
+
+#ifndef readsl
+#define readsl readsl
+static inline void readsl(const volatile void __iomem *addr, void *buffer,
+			  unsigned int count)
+{
+	if (count) {
+		u32 *buf = buffer;
+
+		do {
+			u32 x = __raw_readl(addr);
+			*buf++ = x;
+		} while (--count);
+	}
+}
+#endif
+
+#ifndef readsq
+#define readsq readsq
+static inline void readsq(const volatile void __iomem *addr, void *buffer,
+			  unsigned int count)
+{
+	if (count) {
+		u64 *buf = buffer;
+
+		do {
+			u64 x = __raw_readq(addr);
+			*buf++ = x;
+		} while (--count);
+	}
+}
+#endif
+
+#ifndef writesb
+#define writesb writesb
+static inline void writesb(volatile void __iomem *addr, const void *buffer,
+			   unsigned int count)
+{
+	if (count) {
+		const u8 *buf = buffer;
+
+		do {
+			__raw_writeb(*buf++, addr);
+		} while (--count);
+	}
+}
+#endif
+
+#ifndef writesw
+#define writesw writesw
+static inline void writesw(volatile void __iomem *addr, const void *buffer,
+			   unsigned int count)
+{
+	if (count) {
+		const u16 *buf = buffer;
+
+		do {
+			__raw_writew(*buf++, addr);
+		} while (--count);
+	}
+}
+#endif
+
+#ifndef writesl
+#define writesl writesl
+static inline void writesl(volatile void __iomem *addr, const void *buffer,
+			   unsigned int count)
+{
+	if (count) {
+		const u32 *buf = buffer;
+
+		do {
+			__raw_writel(*buf++, addr);
+		} while (--count);
+	}
+}
+#endif
+
+#ifndef writesq
+#define writesq writesq
+static inline void writesq(volatile void __iomem *addr, const void *buffer,
+			   unsigned int count)
+{
+	if (count) {
+		const u64 *buf = buffer;
+
+		do {
+			__raw_writeq(*buf++, addr);
+		} while (--count);
+	}
+}
+#endif
+
+#endif /* _TOOLS_ASM_GENERIC_IO_H */

tools/include/asm/io.h

···
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _TOOLS_ASM_IO_H
+#define _TOOLS_ASM_IO_H
+
+#include <asm-generic/io.h>
+
+#endif /* _TOOLS_ASM_IO_H */

tools/include/linux/io.h

···
 #ifndef _TOOLS_IO_H
 #define _TOOLS_IO_H
 
-#endif
+#include <asm/io.h>
+
+#endif /* _TOOLS_IO_H */