Re: [Qemu-devel] [PATCH V3 6/8] hw/dma.c: replace register_ioport*

[Avi Kivity]

On 04/05/2012 06:33 PM, Julien Grall wrote:
> This patch replaces all register_ioport* be the new memory API functions.
> It permits to use the new Memory stuff like listener.
>
>  enum {
> @@ -149,7 +151,7 @@ static inline int getff (struct dma_cont *d)
>      return ff;
>  }
>  
> -static uint32_t read_chan (void *opaque, uint32_t nport)
> +static uint64_t read_chan(void *opaque, uint64_t nport, unsigned size)
>  {
>      struct dma_cont *d = opaque;
>      int ichan, nreg, iport, ff, val, dir;
> @@ -171,7 +173,8 @@ static uint32_t read_chan (void *opaque, uint32_t nport)
>      return (val >> (d->dshift + (ff << 3))) & 0xff;
>  }
>  
> -static void write_chan (void *opaque, uint32_t nport, uint32_t data)
> +static void write_chan(void *opaque, target_phys_addr_t nport, uint64_t data,
> +                       unsigned size)
>  {
>      struct dma_cont *d = opaque;
>      int iport, ichan, nreg;
> @@ -189,7 +192,8 @@ static void write_chan (void *opaque, uint32_t nport, 
> uint32_t data)
>      }
>  }
>  
> +
>  /* dshift = 0: 8 bit DMA, 1 = 16 bit DMA */
>  static void dma_init2(struct dma_cont *d, int base, int dshift,
>                        int page_base, int pageh_base,
>                        qemu_irq *cpu_request_exit)
>  {
> -    static const int page_port_list[] = { 0x1, 0x2, 0x3, 0x7 };
>      int i;
>  
>      d->dshift = dshift;
>      d->cpu_request_exit = cpu_request_exit;
>      for (i = 0; i < 8; i++) {
> -        register_ioport_write (base + (i << dshift), 1, 1, write_chan, d);
> -        register_ioport_read (base + (i << dshift), 1, 1, read_chan, d);
> +        memory_region_init_io(&d->channel_io[i], &channel_io_ops, d,
> +                              "dma-chan", 1);
> +        memory_region_add_subregion(isa_address_space_io(NULL),
> +                                    base + (i << dshift), &d->channel_io[i]);
>      }
>

This isn't quite correct.  MemoryRegion callback addresses are offsets,
so 'nport' will always be 0 and ichan/nreg will be incorrect in
read_chan() write_chan().

This is fixable, but dshift makes it quite hard.  We need either two
separate regions for even i and odd i (one region per register), or make
one region per channel of size (2 << dshift), and pass the channel as
the opaque instead of the .  Or even one large region of size (8 <<
dshift), then nport becomes correct again.

Please verify that the other conversions don't suffer from this problem.

-- 
error compiling committee.c: too many arguments to function