Hi Mathieu,
Just a minor comment, with that
Reviewed-by: Arnaud Pouliquen <arnaud.pouliquen@xxxxxx>
On 3/10/21 10:10 PM, Mathieu Poirier wrote:
> If it is possible to detach the remote processor, keep an untouched
> copy of the resource table. That way we can start from the same
> resource table without having to worry about original values or what
> elements the startup code has changed when re-attaching to the remote
> processor.
>
> Signed-off-by: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
> ---
> New for V7:
> New Patch, used to be part of 11/16 in V6.
> ---
> drivers/remoteproc/remoteproc_core.c | 77 ++++++++++++++++++++++++++++
> include/linux/remoteproc.h | 3 ++
> 2 files changed, 80 insertions(+)
>
> diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
> index 5eaa47c3ba92..e9ea2558432d 100644
> --- a/drivers/remoteproc/remoteproc_core.c
> +++ b/drivers/remoteproc/remoteproc_core.c
> @@ -1556,6 +1556,24 @@ 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;
> @@ -1563,6 +1581,59 @@ 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.
> @@ -1721,6 +1792,9 @@ 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);
> +
Something seems missing here to treat the error case.
Regards,
Arnaud
> /* Tell the remote processor the core isn't available anymore */
> ret = rproc->ops->detach(rproc);
> if (ret) {
> @@ -1997,6 +2071,9 @@ 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 e1c843c19cc6..e5f52a12a650 100644
> --- a/include/linux/remoteproc.h
> +++ b/include/linux/remoteproc.h
> @@ -514,6 +514,8 @@ 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
> @@ -550,6 +552,7 @@ 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;
>
