Re: mp_machdep.c (was Re: [Fwd: Re: Bug reports requested - acpi])

From: John Baldwin <jhb_at_FreeBSD.org>
Date: Mon, 20 Sep 2004 16:52:24 -0400
On Monday 20 September 2004 02:46 pm, Roman Kurakin wrote:
> Hi,
>
>     I have problem with one of my SMP systems (see end of letter).
> It looks that following patch:
>
> Index: mp_machdep.c
> ===================================================================
> RCS file: /home/ncvs/src/sys/i386/i386/mp_machdep.c,v
> retrieving revision 1.238
> diff -u -r1.238 mp_machdep.c
> --- mp_machdep.c        1 Sep 2004 06:42:01 -0000       1.238
> +++ mp_machdep.c        20 Sep 2004 18:20:49 -0000
> _at__at_ -747,6 +747,11 _at__at_
>         POSTCODE(INSTALL_AP_TRAMP_POST);
>
>         pmap_kenter(boot_address + KERNBASE, boot_address);
> +#ifdef I386_CPU
> +       invltlb();
> +#else
> +       invlpg((u_int)dst);
> +#endif
>         for (x = 0; x < size; ++x)
>                 *dst++ = *src++;
>
> solves the problem. I'll check it on not very recent hacked current.
> So this is initial request. I'll check it with current current without my
> hacks to double check that this works always and inform if this helps.
>
>     The intent of this letter to ask community if this workaround for my
> problem or real bug fix. If this is only workaround please let me know
> and I'll continue to dig with version I currently use.
> (I don't like workarounds)
>
> Best regards,
>                       Roman Kurakin

It's probably cleaner to use pmap_invalidate_range().  Something like:

Index: mp_machdep.c
===================================================================
RCS file: /usr/cvs/src/sys/i386/i386/mp_machdep.c,v
retrieving revision 1.238
diff -u -r1.238 mp_machdep.c
--- mp_machdep.c	1 Sep 2004 06:42:01 -0000	1.238
+++ mp_machdep.c	20 Sep 2004 20:50:35 -0000
_at__at_ -738,15 +738,19 _at__at_
 	int     x;
 	int     size = *(int *) ((u_long) & bootMP_size);
 	u_char *src = (u_char *) ((u_long) bootMP);
-	u_char *dst = (u_char *) boot_address + KERNBASE;
+	u_char *dst;
 	u_int   boot_base = (u_int) bootMP;
 	u_int8_t *dst8;
 	u_int16_t *dst16;
 	u_int32_t *dst32;
+	vm_offset_t va;
 
 	POSTCODE(INSTALL_AP_TRAMP_POST);
 
-	pmap_kenter(boot_address + KERNBASE, boot_address);
+	va = boot_address + KERNBASE;
+	pmap_kenter(va, boot_address);
+	pmap_invalidate_range(kernel_pmap, va, va + size);
+	dst = (u_char *)va;
 	for (x = 0; x < size; ++x)
 		*dst++ = *src++;
 
It seems odd that this is needed though.  Does it go away if you use 
DISABLE_PSE or DISABLE_PGE?

-- 
John Baldwin <jhb_at_FreeBSD.org>  <><  http://www.FreeBSD.org/~jhb/
"Power Users Use the Power to Serve"  =  http://www.FreeBSD.org
Received on Mon Sep 20 2004 - 18:53:32 UTC

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