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-rw-r--r--drivers/remoteproc/remoteproc_core.c81
-rw-r--r--include/linux/remoteproc.h3
2 files changed, 84 insertions, 0 deletions
diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
index 78a36a3723ec..57c851d22ba6 100644
--- a/drivers/remoteproc/remoteproc_core.c
+++ b/drivers/remoteproc/remoteproc_core.c
@@ -1562,6 +1562,24 @@ static int rproc_set_rsc_table(struct rproc *rproc)
return ret;
}
+ /*
+ * If it is possible to detach the remote processor, keep an untouched
+ * copy of the resource table. That way we can start fresh again when
+ * the remote processor is re-attached, that is:
+ *
+ * DETACHED -> ATTACHED -> DETACHED -> ATTACHED
+ *
+ * Free'd in rproc_reset_rsc_table_on_detach() and
+ * rproc_reset_rsc_table_on_stop().
+ */
+ if (rproc->ops->detach) {
+ rproc->clean_table = kmemdup(table_ptr, table_sz, GFP_KERNEL);
+ if (!rproc->clean_table)
+ return -ENOMEM;
+ } else {
+ rproc->clean_table = NULL;
+ }
+
rproc->cached_table = NULL;
rproc->table_ptr = table_ptr;
rproc->table_sz = table_sz;
@@ -1569,6 +1587,59 @@ static int rproc_set_rsc_table(struct rproc *rproc)
return 0;
}
+static int rproc_reset_rsc_table_on_detach(struct rproc *rproc)
+{
+ struct resource_table *table_ptr;
+
+ /* A resource table was never retrieved, nothing to do here */
+ if (!rproc->table_ptr)
+ return 0;
+
+ /*
+ * If we made it to this point a clean_table _must_ have been
+ * allocated in rproc_set_rsc_table(). If one isn't present
+ * something went really wrong and we must complain.
+ */
+ if (WARN_ON(!rproc->clean_table))
+ return -EINVAL;
+
+ /* Remember where the external entity installed the resource table */
+ table_ptr = rproc->table_ptr;
+
+ /*
+ * If we made it here the remote processor was started by another
+ * entity and a cache table doesn't exist. As such make a copy of
+ * the resource table currently used by the remote processor and
+ * use that for the rest of the shutdown process. The memory
+ * allocated here is free'd in rproc_detach().
+ */
+ rproc->cached_table = kmemdup(rproc->table_ptr,
+ rproc->table_sz, GFP_KERNEL);
+ if (!rproc->cached_table)
+ return -ENOMEM;
+
+ /*
+ * Use a copy of the resource table for the remainder of the
+ * shutdown process.
+ */
+ rproc->table_ptr = rproc->cached_table;
+
+ /*
+ * Reset the memory area where the firmware loaded the resource table
+ * to its original value. That way when we re-attach the remote
+ * processor the resource table is clean and ready to be used again.
+ */
+ memcpy(table_ptr, rproc->clean_table, rproc->table_sz);
+
+ /*
+ * The clean resource table is no longer needed. Allocated in
+ * rproc_set_rsc_table().
+ */
+ kfree(rproc->clean_table);
+
+ return 0;
+}
+
/*
* Attach to remote processor - similar to rproc_fw_boot() but without
* the steps that deal with the firmware image.
@@ -1727,6 +1798,13 @@ static int __rproc_detach(struct rproc *rproc)
/* Stop any subdevices for the remote processor */
rproc_stop_subdevices(rproc, false);
+ /* the installed resource table is no longer accessible */
+ ret = rproc_reset_rsc_table_on_detach(rproc);
+ if (ret) {
+ dev_err(dev, "can't reset resource table: %d\n", ret);
+ return ret;
+ }
+
/* Tell the remote processor the core isn't available anymore */
ret = rproc->ops->detach(rproc);
if (ret) {
@@ -2003,6 +2081,9 @@ int rproc_detach(struct rproc *rproc)
rproc_disable_iommu(rproc);
+ /* Free the copy of the resource table */
+ kfree(rproc->cached_table);
+ rproc->cached_table = NULL;
rproc->table_ptr = NULL;
out:
mutex_unlock(&rproc->lock);
diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h
index fc2cca600423..8b795b544f75 100644
--- a/include/linux/remoteproc.h
+++ b/include/linux/remoteproc.h
@@ -516,6 +516,8 @@ struct rproc_dump_segment {
* @recovery_disabled: flag that state if recovery was disabled
* @max_notifyid: largest allocated notify id.
* @table_ptr: pointer to the resource table in effect
+ * @clean_table: copy of the resource table without modifications. Used
+ * when a remote processor is attached or detached from the core
* @cached_table: copy of the resource table
* @table_sz: size of @cached_table
* @has_iommu: flag to indicate if remote processor is behind an MMU
@@ -552,6 +554,7 @@ struct rproc {
bool recovery_disabled;
int max_notifyid;
struct resource_table *table_ptr;
+ struct resource_table *clean_table;
struct resource_table *cached_table;
size_t table_sz;
bool has_iommu;