[PATCH v3 2/3] cxl: Mark context requiring global TLBIs

[Balbir Singh]

On Thu, Aug 3, 2017 at 6:29 AM, Frederic Barrat
<fbarrat at linux.vnet.ibm.com> wrote:
> The PSL and XSL need to see all TLBIs pertinent to the memory contexts
> used on the adapter. For the hash memory model, it is done by making
> all TLBIs global as soon as the cxl driver is in use. For radix, we
> need something similar, but we can refine and only convert to global
> the invalidations for contexts actually used by the device.
>
> So mark the contexts being attached to the cxl adapter as requiring
> global TLBIs.
>

Looking at these bits, I'm wondering the previous code should check
for CONFIG_CXL in mm_is_invalidation_local? That would pretty much cover
BOOK3S_64

> Signed-off-by: Frederic Barrat <fbarrat at linux.vnet.ibm.com>
> ---
>  drivers/misc/cxl/api.c    | 12 ++++++++++--
>  drivers/misc/cxl/cxllib.c |  7 +++++++
>  drivers/misc/cxl/file.c   | 12 ++++++++++--
>  3 files changed, 27 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/misc/cxl/api.c b/drivers/misc/cxl/api.c
> index 1a138c83f877..d3f3fdede755 100644
> --- a/drivers/misc/cxl/api.c
> +++ b/drivers/misc/cxl/api.c
> @@ -332,8 +332,17 @@ int cxl_start_context(struct cxl_context *ctx, u64 wed,
>                 cxl_context_mm_count_get(ctx);
>
>                 /* decrement the use count */
> -               if (ctx->mm)
> +               if (ctx->mm) {
>                         mmput(ctx->mm);
> +#ifdef CONFIG_PPC_BOOK3S_64
> +                       mm_context_set_global_tlbi(&ctx->mm->context);

Do we have CXL for non PPC_BOOK3S_64?

> +                       /*
> +                        * Barrier guarantees that the device will
> +                        * receive all TLBIs from that point on
> +                        */
> +                       wmb();

smp_wmb();

> +#endif
> +               }
>         }

The other comments are the same as this (in the snip'd code)

Balbir