remoteproc: Add new get_loaded_rsc_table() to rproc_ops

Add a new get_loaded_rsc_table() operation in order to support
scenarios where the remoteproc core has booted a remote processor
and detaches from it. When re-attaching to the remote processor,
the core needs to know where the resource table has been placed
in memory.

Signed-off-by: Mathieu Poirier <[e-mail]>
Reviewed-by: Arnaud Pouliquen <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Bjorn Andersson <[e-mail]>

drivers/remoteproc/remoteproc_core.c

···
 	return ret;
 }
 
+static int rproc_set_rsc_table(struct rproc *rproc)
+{
+	struct resource_table *table_ptr;
+	struct device *dev = &rproc->dev;
+	size_t table_sz;
+	int ret;
+
+	table_ptr = rproc_get_loaded_rsc_table(rproc, &table_sz);
+	if (!table_ptr) {
+		/* Not having a resource table is acceptable */
+		return 0;
+	}
+
+	if (IS_ERR(table_ptr)) {
+		ret = PTR_ERR(table_ptr);
+		dev_err(dev, "can't load resource table: %d\n", ret);
+		return ret;
+	}
+
+	rproc->cached_table = NULL;
+	rproc->table_ptr = table_ptr;
+	rproc->table_sz = table_sz;
+
+	return 0;
+}
+
 /*
  * Attach to remote processor - similar to rproc_fw_boot() but without
  * the steps that deal with the firmware image.
···
 	if (ret) {
 		dev_err(dev, "can't enable iommu: %d\n", ret);
 		return ret;
+	}
+
+	ret = rproc_set_rsc_table(rproc);
+	if (ret) {
+		dev_err(dev, "can't load resource table: %d\n", ret);
+		goto disable_iommu;
 	}
 
 	/* reset max_notifyid */

drivers/remoteproc/remoteproc_internal.h

···
 }
 
 static inline
+struct resource_table *rproc_get_loaded_rsc_table(struct rproc *rproc,
+						  size_t *size)
+{
+	if (rproc->ops->get_loaded_rsc_table)
+		return rproc->ops->get_loaded_rsc_table(rproc, size);
+
+	return NULL;
+}
+
+static inline
 bool rproc_u64_fit_in_size_t(u64 val)
 {
 	if (sizeof(size_t) == sizeof(u64))

include/linux/remoteproc.h

···
  * RSC_HANDLED if resource was handled, RSC_IGNORED if not handled and a
  * negative value on error
  * @load_rsc_table:	load resource table from firmware image
- * @find_loaded_rsc_table: find the loaded resouce table
+ * @find_loaded_rsc_table: find the loaded resource table from firmware image
+ * @get_loaded_rsc_table: get resource table installed in memory
+ *			  by external entity
  * @load:		load firmware to memory, where the remote processor
  *			expects to find it
  * @sanity_check:	sanity check the fw image
···
 			  int offset, int avail);
 	struct resource_table *(*find_loaded_rsc_table)(
 				struct rproc *rproc, const struct firmware *fw);
+	struct resource_table *(*get_loaded_rsc_table)(
+				struct rproc *rproc, size_t *size);
 	int (*load)(struct rproc *rproc, const struct firmware *fw);
 	int (*sanity_check)(struct rproc *rproc, const struct firmware *fw);
 	u64 (*get_boot_addr)(struct rproc *rproc, const struct firmware *fw);