libpayload: x86: Add read/write{8,16,32} variants that match coreboot

Add the now coreboot standard MMIO read/write accessors that were
already defined for other architectures but not x86.

This leaves the old read/write{b,w,l} variants in place as was done
on the other architectures, presumably to support old payloads that
have not been updated.

BUG=chrome-os-partner:43072
BRANCH=none
TEST=emerge-glados libpayload
CQ-DEPEND=CL:294711

Change-Id: I5ae3d755adcef0f6ff27aaa7c35a5b12ddc32e22
Signed-off-by: Patrick Georgi <patrick@georgi-clan.de>
Original-Commit-Id: c09dd557050e3002fa5b8504980d72d4cb79a56c
Original-Change-Id: I58d928338335d3fe4bb7fe2bdc9c2967d8689118
Original-Signed-off-by: Duncan Laurie <dlaurie@chromium.org>
Original-Reviewed-on: https://chromium-review.googlesource.com/294565
Original-Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: http://review.coreboot.org/11405
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Reviewed-by: Alexander Couzens <lynxis@fe80.eu>

payloads/libpayload/include/x86/arch/io.h

@@ -31,6 +31,16 @@
 #ifndef _ARCH_IO_H
 #define _ARCH_IO_H
 
+#include <inttypes.h>
+
+/*
+ * readb/w/l writeb/w/l are deprecated. use read8/16/32 and write8/16/32
+ * instead for future development.
+ *
+ * TODO: make the existing code use read8/16/32 and write8/16/32 then remove
+ * readb/w/l and writeb/w/l.
+ */
+
 #define readb(_a) (*(volatile const unsigned char *) (_a))
 #define readw(_a) (*(volatile const unsigned short *) (_a))
 #define readl(_a) (*(volatile const unsigned int *) (_a))
@@ -39,6 +49,36 @@
 #define writew(_v, _a) (*(volatile unsigned short *) (_a) = (_v))
 #define writel(_v, _a) (*(volatile unsigned int *) (_a) = (_v))
 
+static inline __attribute__((always_inline)) uint8_t read8(const volatile void *addr)
+{
+	return *((volatile uint8_t *)(addr));
+}
+
+static inline __attribute__((always_inline)) uint16_t read16(const volatile void *addr)
+{
+	return *((volatile uint16_t *)(addr));
+}
+
+static inline __attribute__((always_inline)) uint32_t read32(const volatile void *addr)
+{
+	return *((volatile uint32_t *)(addr));
+}
+
+static inline __attribute__((always_inline)) void write8(volatile void *addr, uint8_t value)
+{
+	*((volatile uint8_t *)(addr)) = value;
+}
+
+static inline __attribute__((always_inline)) void write16(volatile void *addr, uint16_t value)
+{
+	*((volatile uint16_t *)(addr)) = value;
+}
+
+static inline __attribute__((always_inline)) void write32(volatile void *addr, uint32_t value)
+{
+	*((volatile uint32_t *)(addr)) = value;
+}
+
 static inline unsigned int inl(int port)
 {
 	unsigned long val;