Re: [Qemu-devel] Re: [PATCH] sparc32: ledma extra registers

[Andreas Färber]

Am 18.12.2010 um 19:53 schrieb Blue Swirl:

> On Sat, Dec 18, 2010 at 5:09 PM, Bob Breuer <address@hidden> wrote:
> > ledma has 0x20 bytes of registers according to OBP, and at least  
> > Solaris9
> > reads the 5th register which is beyond what we've mapped.  So let's  
> > setup
> > a flag (inspired by a previous patch from Blue Swirl) to identify  
> > ledma
> > from espdma, and map another 16 bytes of registers which return 0.
> >
> > Signed-off-by: Bob Breuer <address@hidden>

I'm not familar with that part of code but...

> > diff --git a/hw/sparc32_dma.c b/hw/sparc32_dma.c
> > index e78f025..56be8c8 100644
> > --- a/hw/sparc32_dma.c
> > +++ b/hw/sparc32_dma.c

> > @@ -165,6 +169,9 @@ static uint32_t dma_mem_readl(void *opaque,  
> > target_phys_addr_t addr)
> >     DMAState *s = opaque;
> >     uint32_t saddr;
> >
> > +    if (s->is_ledma && (addr > DMA_MAX_REG_OFFSET)) {
> > +        return 0; /* extra mystery register(s) */

Wouldn't it be a good idea to trace these "mystery" reads...

> > +    }
> >     saddr = (addr & DMA_MASK) >> 2;
> >     trace_sparc32_dma_mem_readl(addr, s->dmaregs[saddr]);
> >     return s->dmaregs[saddr];
> > @@ -175,6 +182,9 @@ static void dma_mem_writel(void *opaque,  
> > target_phys_addr_t addr, uint32_t val)
> >     DMAState *s = opaque;
> >     uint32_t saddr;
> >
> > +    if (s->is_ledma && (addr > DMA_MAX_REG_OFFSET)) {
> > +        return; /* extra mystery register(s) */

...and writes? We return just before the tracepoints fire.

Andreas

> > +    }
> >     saddr = (addr & DMA_MASK) >> 2;
> >     trace_sparc32_dma_mem_writel(addr, s->dmaregs[saddr], val);
> >     switch (saddr) {