[coreboot] New patch to review for coreboot: 1c4e003 Fixed broken MTRR for >4GB memory on AMD K8 fam 0fh rev <=E

[yhlu]

On Thu, Oct 6, 2011 at 9:26 AM, Oskar Enoksson <gerrit at coreboot.org> wrote:
> Oskar Enoksson (enok at lysator.liu.se) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/238
>
> -gerrit
>
> commit 1c4e003269ed43e3d46c60f56e62bcb1049a3fc0
> Author: Oskar Enoksson <enok at lysator.liu.se>
> Date:   Thu Oct 6 18:21:19 2011 +0200
>
>    Fixed broken MTRR for >4GB memory on AMD K8 fam 0fh rev <=E
>
>    AMD K8 rev F and later implements a bit SYSCFG_MSR_TOM2WB in SYSCFG_MSR to
>    mark dram memory above 4GB as WB. However, AMD K8
>    rev E and earlier don't implement this bit and therefore need
>    MTRR spanning dram memory above 4GB. The current implementation
>    of amd_setup_mtrrs never generate MTRR above 4GB.
>    This caused memory > 4GB not to be recognized in e.g. Linux on those
>    rev E or older platforms. This commit should fix that bug.
>
>    Signed-off-by: Oskar Enoksson <enok at lysator.liu.se>
>    Change-Id: Ie568a52a8eb355969c86964d5afc4692e60f69c1
> ---
>  src/cpu/amd/mtrr/amd_mtrr.c |   18 +++++++++++++++---
>  1 files changed, 15 insertions(+), 3 deletions(-)
>
> diff --git a/src/cpu/amd/mtrr/amd_mtrr.c b/src/cpu/amd/mtrr/amd_mtrr.c
> index 623a344..93a3bba 100644
> --- a/src/cpu/amd/mtrr/amd_mtrr.c
> +++ b/src/cpu/amd/mtrr/amd_mtrr.c
> @@ -112,7 +112,13 @@ void amd_setup_mtrrs(void)
>        struct mem_state state;
>        unsigned long i;
>        msr_t msr, sys_cfg;
> -
> +       // Test if this CPU is a Fam 0Fh rev. F or later
> +       const int is_revF =
> +               ((cpuid_eax(0x80000001)&0x00000f00)>>8 >= 0xf) ||
> +               (((cpuid_eax(0x80000001)&0x00000f00)>>8 == 0xf) &&
> +                ((cpuid_eax(0x80000001)&0x000f0000)>>16 >= 0x4));
> +       if(is_revF)
> +               printk(BIOS_DEBUG, "Detected CPU Fam 0Fh rev.F or later\n");

should be configuration option instead of run-time checking.

There is no MB that will support revE and revF at same time. they are
different sockets

Yinghai