[Qemu-devel] Re: [PATCH] sparc32 protect read-only bits in DMA CSR registers

[Artyom Tarasenko <atar4qemu@googlemail.com>]

2010/5/22 Blue Swirl <blauwirbel@gmail.com>:
> Thanks, applied. You forgot SoB-line, I copied it from the previous version.

Sorry. Btw, is there a way to tell 'format-patch' to always include it?
Can't find it in the git docs. Otherwise I'll define an alias so I won't
need to remember about the '-s' switch.

> On Sat, May 22, 2010 at 8:38 AM, Artyom Tarasenko
> <atar4qemu@googlemail.com> wrote:
>> On a real hardware changing read-only bits has no effect
>> Use a mask common for SCSI and Ethernet registers. The crucial
>> bit is DMA_INTR, because setting or clearing it may produce
>> spurious interrupts.
>>
>> This patch allows booting Solaris 2.3
>> ---
>>  hw/sparc32_dma.c |   12 ++++++++----
>>  1 files changed, 8 insertions(+), 4 deletions(-)
>>
>> diff --git a/hw/sparc32_dma.c b/hw/sparc32_dma.c
>> index 3ceb851..b521707 100644
>> --- a/hw/sparc32_dma.c
>> +++ b/hw/sparc32_dma.c
>> @@ -62,6 +62,9 @@
>>  #define DMA_DRAIN_FIFO 0x40
>>  #define DMA_RESET 0x80
>>
>> +/* XXX SCSI and ethernet should have different read-only bit masks */
>> +#define DMA_CSR_RO_MASK 0xfe000007
>> +
>>  typedef struct DMAState DMAState;
>>
>>  struct DMAState {
>> @@ -187,7 +190,7 @@ static void dma_mem_writel(void *opaque, target_phys_addr_t addr, uint32_t val)
>>     switch (saddr) {
>>     case 0:
>>         if (val & DMA_INTREN) {
>> -            if (val & DMA_INTR) {
>> +            if (s->dmaregs[0] & DMA_INTR) {
>>                 DPRINTF("Raise IRQ\n");
>>                 qemu_irq_raise(s->irq);
>>             }
>> @@ -204,16 +207,17 @@ static void dma_mem_writel(void *opaque, target_phys_addr_t addr, uint32_t val)
>>             val &= ~DMA_DRAIN_FIFO;
>>         } else if (val == 0)
>>             val = DMA_DRAIN_FIFO;
>> -        val &= 0x0fffffff;
>> +        val &= ~DMA_CSR_RO_MASK;
>>         val |= DMA_VER;
>> +        s->dmaregs[0] = (s->dmaregs[0] & DMA_CSR_RO_MASK) | val;
>>         break;
>>     case 1:
>>         s->dmaregs[0] |= DMA_LOADED;
>> -        break;
>> +        /* fall through */
>>     default:
>> +        s->dmaregs[saddr] = val;
>>         break;
>>     }
>> -    s->dmaregs[saddr] = val;
>>  }
>>
>>  static CPUReadMemoryFunc * const dma_mem_read[3] = {
>> --
>> 1.6.2.5
>>
>>
>



-- 
Regards,
Artyom Tarasenko

solaris/sparc under qemu blog: http://tyom.blogspot.com/