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

From: Alastair D'Silva
Date: Wed Mar 13 2019 - 00:16:28 EST


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>
---
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
*
--
2.20.1