> You patch is OK. Just two minor comments:
>
> 1) make the enable_write_allocate an _initfunc so that the code is
> discarded after boot and doesn't bloat other people's kernels (who may
> not have an AMD).
I did it;
and I did some more changes:
* Cosmetic cleanup (thanks to Philipp Rumpf)
* fix nasty bug - enabling write allocate failed if RAM size was 128MB or
greater
> 2) Move the code to the amd_model function. Although currently that
> function is misnamed, since it's used for the Cyrix MediaGX detection
> too.
> Probably separate the extended cpuid part, from the real AMD specific
> part. That will save some branch code (for what that may be worth).
I didn't do it. I should look and think, how to do in the best way.
-- With best wishes, Alexey Vyskubov. This is a message. Or something silly like that.--_=XFMail.1.3.p0.Linux:990117231852:516=_ Content-Disposition: attachment; filename="k6-patch" Content-Description: k6-patch Content-Type: text/plain; charset=KOI8-R; name=k6-patch; SizeOnDisk=2168 Content-Transfer-Encoding: 7bit
--- linux/arch/i386/kernel/setup.c.was Sun Jan 17 12:17:11 1999 +++ linux/arch/i386/kernel/setup.c Sun Jan 17 23:14:26 1999 @@ -601,6 +601,30 @@ static char *cpu_vendor_names[] __initdata = { "Intel", "Cyrix", "AMD", "UMC", "NexGen", "Centaur" }; +#define AMD_WHCR 0xc0000082 /* AMD MSR WHCR */ + +__initfunc(u32 enable_write_allocate (u32 size)) +{ + u32 ra, rd; + rd = 0; + + ra = size >> 2; /* EAX = 2*(RAM/4) */ + ra = (ra << 1) | 1; /* +1 for no memory hole at 15-16MB */ + + +#define walloc(msr, val1, val2) __asm__ __volatile__ (" pushf + cli + wbinvd + wrmsr + popf"\ + : /* no outputs */\ + : "c" (msr),\ + "a" (val1), "d" (val2)) + walloc(AMD_WHCR, ra, rd); + rdmsr(AMD_WHCR, ra, rd); /* Let's see what's happened */ + ra = (ra & 0xfe) << 1; /* Drop last bit (memory hole) */ + return(ra); +} __initfunc(void print_cpu_info(struct cpuinfo_x86 *c)) { @@ -621,8 +645,51 @@ if (c->x86_mask || c->cpuid_level>=0) printk(" stepping %02x", c->x86_mask); - - if(c->x86_vendor == X86_VENDOR_CENTAUR) + + if ( (c->x86_vendor == X86_VENDOR_AMD) && + ((c->x86_model == 6) || (c->x86_model == 7))) + { + + u32 ra, rd; + u32 ram; + + printk("\nAMD K6 processor, model %d found.", c->x86_model); + printk("\nChecking write allocate state... "); + + ram = max_mapnr * (PAGE_SIZE >> 10); /* RAM size in Kb */ + ram >>= 10; /* RAM size in Mb */ + + rdmsr(AMD_WHCR, ra, rd); + ra = (ra & 0xfe) << 1; + + if (ra) { + printk("Write allocate is enabled for %d MB of memory", ra); + } else { + printk("Write allocate is disabled."); + } + + if (!(ra == ram)) { + printk("\nTrying to enable write alocate for %d MB of memory", ram); + ra = enable_write_allocate(ram); + + if (!(ra == ram)) { + printk("\nFailed!!!"); + } + printk("\nWrite allocate is enabled for %d MB of memory", ra); + } + + rdmsr(AMD_WHCR, ra, rd); + + if (ra & 0x100) { + printk("\nWARNING: WCDE bit is 1."); + } + + if (!(ra & 0x1)) { + printk("\nWARNING: Memory hole at 15-16M is enabled."); + } + } + + if (c->x86_vendor == X86_VENDOR_CENTAUR) { u32 hv,lv; rdmsr(0x107, lv, hv);
--_=XFMail.1.3.p0.Linux:990117231852:516=_-- End of MIME message
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