Hi Huawei,

-----Original Message-----
From: dev <redacted> On Behalf Of ???(????)
Sent: Thursday, March 11, 2021 01:37
To: david.marchand@redhat.com; maxime.coquelin@redhat.com; Yigit, Ferruh <redacted>
Cc: dev@dpdk.org; Burakov, Anatoly <redacted>; xuemingl@nvidia.com; grive@u256.net;
谢华伟(此时此刻） [off-list ref]
Subject: [dpdk-dev] [PATCH v11 2/2] bus/pci: support MMIO in PCI ioport accessors

With I/O BAR, we get PIO(port-mapped I/O) address.
With MMIO(memory-mapped I/O) BAR, we get mapped virtual address.
We distinguish PIO and MMIO by their address range like how kernel does,
i.e, address below 64K is PIO.
ioread/write8/16/32 is provided to access PIO/MMIO.
By the way, for virtio on arch other than x86, BAR flag indicates PIO
but is mapped.

Signed-off-by: huawei xie <redacted>
Reviewed-by: Maxime Coquelin <redacted>
---
 drivers/bus/pci/linux/pci.c     |   4 --
 drivers/bus/pci/linux/pci_uio.c | 156 +++++++++++++++++++++++++++++-----------
 2 files changed, 113 insertions(+), 47 deletions(-)

+#if defined(RTE_ARCH_X86)
+static inline uint8_t ioread8(void *addr)
+{
+	uint8_t val;
+
+	val = (uint64_t)(uintptr_t)addr >= PIO_MAX ?
+		*(volatile uint8_t *)addr :
+		inb_p((unsigned long)addr);
+
+	return val;
+}
+
+static inline uint16_t ioread16(void *addr)
+{
+	uint16_t val;
+
+	val = (uint64_t)(uintptr_t)addr >= PIO_MAX ?
+		*(volatile uint16_t *)addr :
+		inw_p((unsigned long)addr);
+
+	return val;
+}
+
+static inline uint32_t ioread32(void *addr)
+{
+	uint32_t val;
+
+	val = (uint64_t)(uintptr_t)addr >= PIO_MAX ?
+		*(volatile uint32_t *)addr :
+		inl_p((unsigned long)addr);
+
+	return val;
+}
+
+static inline void iowrite8(uint8_t val, void *addr)
+{
+	(uint64_t)(uintptr_t)addr >= PIO_MAX ?
+		*(volatile uint8_t *)addr = val :
+		outb_p(val, (unsigned long)addr);
+}
+
+static inline void iowrite16(uint16_t val, void *addr)
+{
+	(uint64_t)(uintptr_t)addr >= PIO_MAX ?
+		*(volatile uint16_t *)addr = val :
+		outw_p(val, (unsigned long)addr);
+}
+
+static inline void iowrite32(uint32_t val, void *addr)
+{
+	(uint64_t)(uintptr_t)addr >= PIO_MAX ?
+		*(volatile uint32_t *)addr = val :
+		outl_p(val, (unsigned long)addr);
+}
+#else
+static inline uint8_t ioread8(void *addr)
+{
+	return *(volatile uint8_t *)addr;
+}
+
+static inline uint16_t ioread16(void *addr)
+{
+	return *(volatile uint16_t *)addr;
+}
+
+static inline uint32_t ioread32(void *addr)
+{
+	return *(volatile uint32_t *)addr;
+}
+
+static inline void iowrite8(uint8_t val, void *addr)
+{
+	*(volatile uint8_t *)addr = val;
+}
+
+static inline void iowrite16(uint16_t val, void *addr)
+{
+	*(volatile uint16_t *)addr = val;
+}
+
+static inline void iowrite32(uint32_t val, void *addr)
+{
+	*(volatile uint32_t *)addr = val;
+}
+#endif
+

Like kernel use macro to do pio and mmio, maybe we can also to do so for
making code clean:

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/lib/iomap.c

#define IO_COND(addr, is_pio, is_mmio) do {			\
	unsigned long port = (unsigned long __force)addr;	\
	if (port >= PIO_RESERVED) {				\
		is_mmio;					\
	} else if (port > PIO_OFFSET) {				\
		port &= PIO_MASK;				\
		is_pio;						\
	} else							\
		bad_io_access(port, #is_pio );			\
} while (0)


Like:

#if defined(RTE_ARCH_X86)
#define IO_COND(addr, is_pio, is_mmio) do {           \
	if ((uint64_t)(uintptr_t)addr >= PIO_MAX) {   \
		is_mmio;                              \
	} else {                                      \
		is_pio;                               \
	}                                             \
} while (0)
#else
#define IO_COND(addr, is_pio, is_mmio) do {           \
		is_mmio;                              \
} while (0)
#endif

static inline uint8_t ioread8(void *addr)
{
	uint8_t val;

	IO_COND(addr,
		val = inb_p((unsigned long)addr),
		val = *(volatile uint8_t *)addr);

	return val;
}

static inline uint16_t ioread16(void *addr)
{
	uint16_t val;

	IO_COND(addr,
		val = inw_p((unsigned long)addr),
		val = *(volatile uint16_t *)addr);

	return val;
}

static inline uint32_t ioread32(void *addr)
{
	uint32_t val;

	IO_COND(addr,
		val = inl_p((unsigned long)addr),
		val = *(volatile uint32_t *)addr);

	return val;
}

static inline void iowrite8(uint8_t val, void *addr)
{
	IO_COND(addr,
		outb_p(val, (unsigned long)addr),
		*(volatile uint8_t *)addr = val);
}

static inline void iowrite16(uint16_t val, void *addr)
{
	IO_COND(addr,
		outw_p(val, (unsigned long)addr),
		*(volatile uint16_t *)addr = val);
}

static inline void iowrite32(uint32_t val, void *addr)
{
	IO_COND(addr,
		outl_p(val, (unsigned long)addr),
		*(volatile uint32_t *)addr = val);
}