Re: [PATCH v3] hw/cxl: Fix missing write mask for HDM decoder target list registers

[Jonathan Cameron]

On Tue, 7 Jun 2022 09:19:28 -0700
Ben Widawsky <bwidawsk@kernel.org> wrote:

> On 22-06-07 17:07:47, Jonathan Cameron wrote:
> > Without being able to write these registers, no interleaving is possible.
> > More refined checks of HDM register state on commit to follow.
> > 
> > Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> > ---
> > v3: Actually pass the parameter to the call...
> > v2: (Ben Widawsky)
> > - Correctly set a tighter write mask for the endpoint devices where this
> >   register has a different use.
> >   
> >  hw/cxl/cxl-component-utils.c | 11 +++++++++--
> >  1 file changed, 9 insertions(+), 2 deletions(-)
> > 
> > diff --git a/hw/cxl/cxl-component-utils.c b/hw/cxl/cxl-component-utils.c
> > index 7985c9bfca..2208284ee6 100644
> > --- a/hw/cxl/cxl-component-utils.c
> > +++ b/hw/cxl/cxl-component-utils.c
> > @@ -154,7 +154,8 @@ static void ras_init_common(uint32_t *reg_state, 
> > uint32_t *write_msk)
> >      reg_state[R_CXL_RAS_ERR_CAP_CTRL] = 0x00;
> >  }
> >  
> > -static void hdm_init_common(uint32_t *reg_state, uint32_t *write_msk)
> > +static void hdm_init_common(uint32_t *reg_state, uint32_t *write_msk,
> > +                            enum reg_type type)
> >  {
> >      int decoder_count = 1;
> >      int i;
> > @@ -174,6 +175,12 @@ static void hdm_init_common(uint32_t *reg_state, 
> > uint32_t *write_msk)
> >          write_msk[R_CXL_HDM_DECODER0_SIZE_LO + i * 0x20] = 0xf0000000;
> >          write_msk[R_CXL_HDM_DECODER0_SIZE_HI + i * 0x20] = 0xffffffff;
> >          write_msk[R_CXL_HDM_DECODER0_CTRL + i * 0x20] = 0x13ff;
> > +        if (type == CXL2_DEVICE) {
> > +            write_msk[R_CXL_HDM_DECODER0_TARGET_LIST_LO + i * 0x20] = 
> > 0xf0000000;
> > +        } else {
> > +            write_msk[R_CXL_HDM_DECODER0_TARGET_LIST_LO + i * 0x20] = 
> > 0xffffffff;
> > +        }
> > +        write_msk[R_CXL_HDM_DECODER0_TARGET_LIST_HI + i * 0x20] = 
> > 0xffffffff;  
> 
> Should it be (type == CXL2_DEVICE || type == CXL2_TYPE3_DEVICE) ?

Good point, but also for consistency I think we need 
type == CXL2_LOGICAL_DEVICE as well.

We will only exercise the match to CXL2_TYPE3_DEVICE currently
as we don't have any emulation for MLDs (and hence LD) or type 1/2 devices
(CXL2_DEVICE).

I'll send a v4 out tomorrow.

> 
> Otherwise,
> Reviewed-by: Ben Widawsky <ben@bwidawsk.net>
> 
> >      }
> >  }
> >  
> > @@ -239,7 +246,7 @@ void cxl_component_register_init_common(uint32_t 
> > *reg_state, uint32_t *write_msk
> >      }
> >  
> >      init_cap_reg(HDM, 5, 1);
> > -    hdm_init_common(reg_state, write_msk);
> > +    hdm_init_common(reg_state, write_msk, type);
> >  
> >      if (caps < 5) {
> >          return;
> > -- 
> > 2.32.0
> >