On Mon, Oct 7, 2019 at 9:53 PM Bin Meng <bmeng...@gmail.com> wrote:
>
> On Wed, Sep 25, 2019 at 10:58 PM Simon Glass <s...@chromium.org> wrote:
> >
> > Normally U-Boot handles MTRRs through an add/commit process which
> > overwrites all MTRRs. But in very early boot it is not desirable to clear
> > the existing MTRRs since they may be in use and it can cause a hang.
> >
> > Add a new mtrr_set_next_var() function which sets up the next available
> > MTRR to the required region.
> >
> > Signed-off-by: Simon Glass <s...@chromium.org>
> > ---
> >
> > arch/x86/cpu/mtrr.c | 38 +++++++++++++++++++++++++++++++++++++
> > arch/x86/include/asm/mtrr.h | 12 ++++++++++++
> > 2 files changed, 50 insertions(+)
> >
> > diff --git a/arch/x86/cpu/mtrr.c b/arch/x86/cpu/mtrr.c
> > index 6218d149e30..1a7c292fa8b 100644
> > --- a/arch/x86/cpu/mtrr.c
> > +++ b/arch/x86/cpu/mtrr.c
> > @@ -112,3 +112,41 @@ int mtrr_add_request(int type, uint64_t start,
> > uint64_t size)
> >
> > return 0;
> > }
> > +
> > +static int get_var_mtrr_count(void)
> > +{
> > + return msr_read(MSR_MTRR_CAP_MSR).lo & MSR_MTRR_CAP_VCNT;
> > +}
> > +
> > +static int get_free_var_mtrr(void)
> > +{
> > + struct msr_t maskm;
> > + int vcnt;
> > + int i;
> > +
> > + vcnt = get_var_mtrr_count();
> > +
> > + /* Identify the first var mtrr which is not valid */
> > + for (i = 0; i < vcnt; i++) {
> > + maskm = msr_read(MTRR_PHYS_MASK_MSR(i));
> > + if ((maskm.lo & MTRR_PHYS_MASK_VALID) == 0)
> > + return i;
> > + }
> > +
> > + /* No free var mtrr */
> > + return -ENOSPC;
> > +}
> > +
> > +int mtrr_set_next_var(uint type, uint64_t start, uint64_t size)
> > +{
> > + int mtrr;
> > +
> > + mtrr = get_free_var_mtrr();
> > + if (mtrr < 0)
> > + return mtrr;
> > +
> > + set_var_mtrr(mtrr, MTRR_TYPE_WRPROT, start, size);
>
> I think MTRR_TYPE_WRPROT should be parameter 'type'
Fixed this, and
>
> > + debug("MTRR %x: start=%x, size=%x\n", mtrr, (uint)start,
> > (uint)size);
> > +
> > + return 0;
> > +}
> > diff --git a/arch/x86/include/asm/mtrr.h b/arch/x86/include/asm/mtrr.h
> > index 6f29e75ce65..672617256e9 100644
> > --- a/arch/x86/include/asm/mtrr.h
> > +++ b/arch/x86/include/asm/mtrr.h
> > @@ -117,6 +117,18 @@ int mtrr_add_request(int type, uint64_t start,
> > uint64_t size);
> > */
> > int mtrr_commit(bool do_caches);
> >
> > +/**
> > + * mtrr_set_next_var() - set up a variable MTRR
> > + *
> > + * This finds the first free variable MTRR and sets to the given area
> > + *
> > + * @type: Requested type (MTRR_TYPE_)
> > + * @start: Start address
> > + * @size: Size
> > + * @return 0 on success, -ENOSPC if there are no more MTRRs
> > + */
> > +int mtrr_set_next_var(uint type, uint64_t base, uint64_t size);
> > +
> > #endif
> >
> > #if ((CONFIG_XIP_ROM_SIZE & (CONFIG_XIP_ROM_SIZE - 1)) != 0)
> > --
>
> Other than above,
>
> Reviewed-by: Bin Meng <bmeng...@gmail.com>
applied to u-boot-x86/next, thanks!
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