Re: [PATCH 2/7] ocxl: Allow external drivers to use OpenCAPI contexts

[Frederic Barrat]

Le 13/03/2019 Ã 05:15, Alastair D'Silva a ÃcritÂ:
> From: Alastair D'Silva <alastair@xxxxxxxxxxx>
>
> Most OpenCAPI operations require a valid context, so
> exposing these functions to external drivers is necessary.
>
> Signed-off-by: Alastair D'Silva <alastair@xxxxxxxxxxx>
> Reviewed-by: Greg Kurz <groug@xxxxxxxx>
> ---

Patch could also be moved later in the series (same reason as before), but:
Acked-by: Frederic Barrat <fbarrat@xxxxxxxxxxxxx>


>   drivers/misc/ocxl/context.c       |  9 +++++--
>   drivers/misc/ocxl/file.c          |  2 +-
>   drivers/misc/ocxl/ocxl_internal.h |  6 -----
>   include/misc/ocxl.h               | 44 +++++++++++++++++++++++++++++++
>   4 files changed, 52 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/misc/ocxl/context.c b/drivers/misc/ocxl/context.c
> index 3498a0199bde..1534b56f1db1 100644
> --- a/drivers/misc/ocxl/context.c
> +++ b/drivers/misc/ocxl/context.c
> @@ -8,6 +8,7 @@ struct ocxl_context *ocxl_context_alloc(void)
>   {
>   	return kzalloc(sizeof(struct ocxl_context), GFP_KERNEL);
>   }
> +EXPORT_SYMBOL_GPL(ocxl_context_alloc);
>   
>   int ocxl_context_init(struct ocxl_context *ctx, struct ocxl_afu *afu,
>   		struct address_space *mapping)
> @@ -43,6 +44,7 @@ int ocxl_context_init(struct ocxl_context *ctx, struct ocxl_afu *afu,
>   	ocxl_afu_get(afu);
>   	return 0;
>   }
> +EXPORT_SYMBOL_GPL(ocxl_context_init);
>   
>   /*
>    * Callback for when a translation fault triggers an error
> @@ -63,7 +65,7 @@ static void xsl_fault_error(void *data, u64 addr, u64 dsisr)
>   	wake_up_all(&ctx->events_wq);
>   }
>   
> -int ocxl_context_attach(struct ocxl_context *ctx, u64 amr)
> +int ocxl_context_attach(struct ocxl_context *ctx, u64 amr, struct mm_struct *mm)
>   {
>   	int rc;
>   
> @@ -75,7 +77,7 @@ int ocxl_context_attach(struct ocxl_context *ctx, u64 amr)
>   	}
>   
>   	rc = ocxl_link_add_pe(ctx->afu->fn->link, ctx->pasid,
> -			current->mm->context.id, ctx->tidr, amr, current->mm,
> +			mm->context.id, ctx->tidr, amr, mm,
>   			xsl_fault_error, ctx);
>   	if (rc)
>   		goto out;
> @@ -85,6 +87,7 @@ int ocxl_context_attach(struct ocxl_context *ctx, u64 amr)
>   	mutex_unlock(&ctx->status_mutex);
>   	return rc;
>   }
> +EXPORT_SYMBOL_GPL(ocxl_context_attach);
>   
>   static vm_fault_t map_afu_irq(struct vm_area_struct *vma, unsigned long address,
>   		u64 offset, struct ocxl_context *ctx)
> @@ -243,6 +246,7 @@ int ocxl_context_detach(struct ocxl_context *ctx)
>   	}
>   	return 0;
>   }
> +EXPORT_SYMBOL_GPL(ocxl_context_detach);
>   
>   void ocxl_context_detach_all(struct ocxl_afu *afu)
>   {
> @@ -280,3 +284,4 @@ void ocxl_context_free(struct ocxl_context *ctx)
>   	ocxl_afu_put(ctx->afu);
>   	kfree(ctx);
>   }
> +EXPORT_SYMBOL_GPL(ocxl_context_free);
> diff --git a/drivers/misc/ocxl/file.c b/drivers/misc/ocxl/file.c
> index 16eb8a60d5c7..865b3d176431 100644
> --- a/drivers/misc/ocxl/file.c
> +++ b/drivers/misc/ocxl/file.c
> @@ -100,7 +100,7 @@ static long afu_ioctl_attach(struct ocxl_context *ctx,
>   		return -EINVAL;
>   
>   	amr = arg.amr & mfspr(SPRN_UAMOR);
> -	rc = ocxl_context_attach(ctx, amr);
> +	rc = ocxl_context_attach(ctx, amr, current->mm);
>   	return rc;
>   }
>   
> diff --git a/drivers/misc/ocxl/ocxl_internal.h b/drivers/misc/ocxl/ocxl_internal.h
> index 06fd98c989c8..779d15ef60b5 100644
> --- a/drivers/misc/ocxl/ocxl_internal.h
> +++ b/drivers/misc/ocxl/ocxl_internal.h
> @@ -130,15 +130,9 @@ int ocxl_config_check_afu_index(struct pci_dev *dev,
>    */
>   int ocxl_link_update_pe(void *link_handle, int pasid, __u16 tid);
>   
> -struct ocxl_context *ocxl_context_alloc(void);
> -int ocxl_context_init(struct ocxl_context *ctx, struct ocxl_afu *afu,
> -			struct address_space *mapping);
> -int ocxl_context_attach(struct ocxl_context *ctx, u64 amr);
>   int ocxl_context_mmap(struct ocxl_context *ctx,
>   			struct vm_area_struct *vma);
> -int ocxl_context_detach(struct ocxl_context *ctx);
>   void ocxl_context_detach_all(struct ocxl_afu *afu);
> -void ocxl_context_free(struct ocxl_context *ctx);
>   
>   int ocxl_sysfs_add_afu(struct ocxl_afu *afu);
>   void ocxl_sysfs_remove_afu(struct ocxl_afu *afu);
> diff --git a/include/misc/ocxl.h b/include/misc/ocxl.h
> index 3b320c39f0af..ebbfe83cd5a6 100644
> --- a/include/misc/ocxl.h
> +++ b/include/misc/ocxl.h
> @@ -51,6 +51,7 @@ struct ocxl_fn_config {
>   
>   // These are opaque outside the ocxl driver
>   struct ocxl_afu;
> +struct ocxl_context;
>   
>   enum ocxl_endian {
>   	OCXL_BIG_ENDIAN = 0,    /**< AFU data is big-endian */
> @@ -58,6 +59,49 @@ enum ocxl_endian {
>   	OCXL_HOST_ENDIAN = 2,   /**< AFU data is the same endianness as the host */
>   };
>   
> +/**
> + * Allocate space for a new OpenCAPI context
> + *
> + * Returns NULL on failure
> + */
> +struct ocxl_context *ocxl_context_alloc(void);
> +
> +/**
> + * Initialize an OpenCAPI context
> + *
> + * @ctx: The OpenCAPI context to initialize
> + * @afu: The AFU the context belongs to
> + * @mapping: The mapping to unmap when the context is closed (may be NULL)
> + */
> +int ocxl_context_init(struct ocxl_context *ctx, struct ocxl_afu *afu,
> +			struct address_space *mapping);
> +
> +/**
> + * Free an OpenCAPI context
> + *
> + * @ctx: The OpenCAPI context to free
> + */
> +void ocxl_context_free(struct ocxl_context *ctx);
> +
> +/**
> + * Grant access to an MM to an OpenCAPI context
> + * @ctx: The OpenCAPI context to attach
> + * @amr: The value of the AMR register to restrict access
> + * @mm: The mm to attach to the context
> + *
> + * Returns 0 on success, negative on failure
> + */
> +int ocxl_context_attach(struct ocxl_context *ctx, u64 amr,
> +				struct mm_struct *mm);
> +
> +/**
> + * Detach an MM from an OpenCAPI context
> + * @ctx: The OpenCAPI context to attach
> + *
> + * Returns 0 on success, negative on failure
> + */
> +int ocxl_context_detach(struct ocxl_context *ctx);
> +
>   /**
>    * Read a 32 bit value from global MMIO
>    *