Re: [dpdk-dev] [PATCH v11 2/2] bus/pci: support MMIO in PCI ioport accessors

["Wang, Haiyue" <haiyue.wang@intel.com>]

Hi Huawei,

> -----Original Message-----
> From: dev <dev-bounces@dpdk.org> On Behalf Of ???(????)
> Sent: Thursday, March 11, 2021 01:37
> To: david.marchand@redhat.com; maxime.coquelin@redhat.com; Yigit, Ferruh <ferruh.yigit@intel.com>
> Cc: dev@dpdk.org; Burakov, Anatoly <anatoly.burakov@intel.com>; xuemingl@nvidia.com; grive@u256.net;
> 谢华伟(此时此刻） <huawei.xhw@alibaba-inc.com>
> 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 <huawei.xhw@alibaba-inc.com>
> Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>
> ---
>  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);
}

>  void
>  pci_uio_ioport_read(struct rte_pci_ioport *p,
>  		    void *data, size_t len, off_t offset)
> @@ -528,25 +622,13 @@
>  	for (d = data; len > 0; d += size, reg += size, len -= size) {
>  		if (len >= 4) {
>  			size = 4;
> -#if defined(RTE_ARCH_X86)
> -			*(uint32_t *)d = inl(reg);
> -#else
> -			*(uint32_t *)d = *(volatile uint32_t *)reg;
> -#endif
> +			*(uint32_t *)d = ioread32((void *)reg);
>  		} else if (len >= 2) {
>  			size = 2;
> -#if defined(RTE_ARCH_X86)
> -			*(uint16_t *)d = inw(reg);
> -#else
> -			*(uint16_t *)d = *(volatile uint16_t *)reg;
> -#endif
> +			*(uint16_t *)d = ioread16((void *)reg);
>  		} else {
>  			size = 1;
> -#if defined(RTE_ARCH_X86)
> -			*d = inb(reg);
> -#else
> -			*d = *(volatile uint8_t *)reg;
> -#endif
> +			*d = ioread8((void *)reg);
>  		}
>  	}
>  }
> @@ -562,25 +644,13 @@
>  	for (s = data; len > 0; s += size, reg += size, len -= size) {
>  		if (len >= 4) {
>  			size = 4;
> -#if defined(RTE_ARCH_X86)
> -			outl_p(*(const uint32_t *)s, reg);
> -#else
> -			*(volatile uint32_t *)reg = *(const uint32_t *)s;
> -#endif
> +			iowrite32(*(const uint32_t *)s, (void *)reg);
>  		} else if (len >= 2) {
>  			size = 2;
> -#if defined(RTE_ARCH_X86)
> -			outw_p(*(const uint16_t *)s, reg);
> -#else
> -			*(volatile uint16_t *)reg = *(const uint16_t *)s;
> -#endif
> +			iowrite16(*(const uint16_t *)s, (void *)reg);
>  		} else {
>  			size = 1;
> -#if defined(RTE_ARCH_X86)
> -			outb_p(*s, reg);
> -#else
> -			*(volatile uint8_t *)reg = *s;
> -#endif
> +			iowrite8(*s, (void *)reg);
>  		}
>  	}
>  }
> --
> 1.8.3.1