Re: [Qemu-devel] [PATCH 1/3] Add ppc_init_cacheline_sizes() function for OpenBSD.

[Brad]

On 26/05/11 8:20 PM, malc wrote:
> On Thu, 26 May 2011, Brad wrote:
>
> > On 26/05/11 9:15 AM, malc wrote:
> > > On Thu, 26 May 2011, Brad wrote:
> > >
> > > > ----- Original message -----
> > > > > On Wed, 25 May 2011, Brad wrote:
> > > > >
> > > > > > Add ppc_init_cacheline_sizes() function for OpenBSD to fix compilation
> > > > > > of PowerPC host support for OpenBSD/powerpc based architectures.
> > > > > >
> > > > > > Signed-off-by: Brad Smith<address@hidden>
>
> [..snip..]
>
> > Well this is the behavior of our kernel no matter what the CPU type is.
> >
> > from sys/arch/powerpc/cpu.h..
> >
> >
> > #define CACHELINE       32              /* Note that this value is really
> > hardwired */
>
> [..snip..]
>
> I sure hope that OpenBSD doesn't use this value for dcbz/a's on ppc's with
> less than 32 bytes per cache line and am not sure i want to take this
> patch even if the kernel itself does this, not without some nagging printf
> in the init cache line function urging OpenBSD kernel developers to fix
> things..

USE_DCBZ is not defined.

/*
 * Fill the given physical page with zeros.
 */
void
pmap_zero_page(struct vm_page *pg)
{
        paddr_t pa = VM_PAGE_TO_PHYS(pg);
#ifdef USE_DCBZ
        int i;
        paddr_t addr = zero_page;
#endif

        /* simple_lock(&pmap_zero_page_lock); */
        pmap_kenter_pa(zero_page, pa, VM_PROT_READ|VM_PROT_WRITE);
#ifdef USE_DCBZ
        for (i = PAGE_SIZE/CACHELINESIZE; i>0; i--) {
                __asm volatile ("dcbz 0,%0" :: "r"(addr));
                addr += CACHELINESIZE;
        }
#else
        bzero((void *)zero_page, PAGE_SIZE);
#endif
        pmap_kremove_pg(zero_page);
        
        /* simple_unlock(&pmap_zero_page_lock); */
}

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