On Mon, Sep 16, 2019 at 07:54:35AM -0600, Jon Derrick wrote:
> The shadow offset scratchpad was moved to 0x2000-0x2010. Update the
> location to get the correct shadow offset.

Hi Jon,

what does "was moved" mean ? Would this code still work on previous HW ?

We must make sure that the address move is managed seamlessly by the
kernel.

For the time being I have to drop this fix and it is extremely
tight to get it in v5.4, I can't send stable changes that we may
have to revert.

Thanks,
Lorenzo

> Cc: sta...@vger.kernel.org # v5.2+
> Fixes: 6788958e ("PCI: vmd: Assign membar addresses from shadow registers")
> Signed-off-by: Jon Derrick <jonathan.derr...@intel.com>
> ---
>  drivers/pci/controller/vmd.c | 9 ++++++---
>  1 file changed, 6 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/pci/controller/vmd.c b/drivers/pci/controller/vmd.c
> index 2e4da3f51d6b..a35d3f3996d7 100644
> --- a/drivers/pci/controller/vmd.c
> +++ b/drivers/pci/controller/vmd.c
> @@ -31,6 +31,9 @@
>  #define PCI_REG_VMLOCK               0x70
>  #define MB2_SHADOW_EN(vmlock)        (vmlock & 0x2)
>  
> +#define MB2_SHADOW_OFFSET    0x2000
> +#define MB2_SHADOW_SIZE              16
> +
>  enum vmd_features {
>       /*
>        * Device may contain registers which hint the physical location of the
> @@ -578,7 +581,7 @@ static int vmd_enable_domain(struct vmd_dev *vmd, 
> unsigned long features)
>               u32 vmlock;
>               int ret;
>  
> -             membar2_offset = 0x2018;
> +             membar2_offset = MB2_SHADOW_OFFSET + MB2_SHADOW_SIZE;
>               ret = pci_read_config_dword(vmd->dev, PCI_REG_VMLOCK, &vmlock);
>               if (ret || vmlock == ~0)
>                       return -ENODEV;
> @@ -590,9 +593,9 @@ static int vmd_enable_domain(struct vmd_dev *vmd, 
> unsigned long features)
>                       if (!membar2)
>                               return -ENOMEM;
>                       offset[0] = vmd->dev->resource[VMD_MEMBAR1].start -
> -                                             readq(membar2 + 0x2008);
> +                                     readq(membar2 + MB2_SHADOW_OFFSET);
>                       offset[1] = vmd->dev->resource[VMD_MEMBAR2].start -
> -                                             readq(membar2 + 0x2010);
> +                                     readq(membar2 + MB2_SHADOW_OFFSET + 8);
>                       pci_iounmap(vmd->dev, membar2);
>               }
>       }
> -- 
> 2.20.1
> 

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