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;