Re: [dpdk-dev] [PATCH 26/28] net/virtio: use eal I/O device memory read/write API

[Santosh Shukla <santosh.shukla@caviumnetworks.com>]

On Wed, Dec 14, 2016 at 11:02:23AM +0800, Yuanhan Liu wrote:
> On Wed, Dec 14, 2016 at 07:25:56AM +0530, Jerin Jacob wrote:
> >   * Following macros are derived from linux/pci_regs.h, however,
> >   * we can't simply include that header here, as there is no such
> > @@ -320,37 +322,37 @@ static const struct virtio_pci_ops legacy_ops = {
> >  static inline uint8_t
> >  io_read8(uint8_t *addr)
> >  {
> > -	return *(volatile uint8_t *)addr;
> > +	return rte_readb(addr);
> >  }
> 
> Oh, one more comments: why not replacing io_read8 with rte_readb(),
> and do similar for others? Then we don't have to define those wrappers.
> 
> I think you can also do something similar for other patches?

Make sense for the virtio-pci case where API name io_read/write as good as
rte_read/write. However, IMO for other drivers for example ADF_CSR_RD/WR
improves code readability compared to plain rte_read/write.

Also IMO replacing code incident like below 
 
static inline void writel(unsigned int val, volatile void __iomem *addr)
{
-    *(volatile unsigned int *)addr = val;
+    rte_writel(val, addr);
}

with direct rte_read/write more appropriate. does above said make sense
to you?
If so then I will take care for all such driver in V2.

--Santosh.

> 	--yliu
> >  
> >  static inline void
> >  io_write8(uint8_t val, uint8_t *addr)
> >  {
> > -	*(volatile uint8_t *)addr = val;
> > +	rte_writeb(val, addr);
> >  }
> >  
> >  static inline uint16_t
> >  io_read16(uint16_t *addr)
> >  {
> > -	return *(volatile uint16_t *)addr;
> > +	return rte_readw(addr);
> >  }
> >  
> >  static inline void
> >  io_write16(uint16_t val, uint16_t *addr)
> >  {
> > -	*(volatile uint16_t *)addr = val;
> > +	rte_writew(val, addr);
> >  }
> >  
> >  static inline uint32_t
> >  io_read32(uint32_t *addr)
> >  {
> > -	return *(volatile uint32_t *)addr;
> > +	return rte_readl(addr);
> >  }
> >  
> >  static inline void
> >  io_write32(uint32_t val, uint32_t *addr)
> >  {
> > -	*(volatile uint32_t *)addr = val;
> > +	rte_writel(val, addr);
> >  }
> >  
> >  static inline void
> > -- 
> > 2.5.5