Hi Mathieu,
On 2/12/21 12:46 AM, Mathieu Poirier wrote:
> 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 <mathieu.poirier@xxxxxxxxxx>
> ---
> New for V5:
> - Added function rproc_set_loaded_rsc_table() to keep rproc_attach() clean.
> - Setting ->cached_table, ->table_ptr and ->table_sz in the remoteproc core
> rather than the platform drivers.
> ---
> drivers/remoteproc/remoteproc_core.c | 35 ++++++++++++++++++++++++
> drivers/remoteproc/remoteproc_internal.h | 10 +++++++
> include/linux/remoteproc.h | 6 +++-
> 3 files changed, 50 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
> index e6606d10a4c8..741bc20de437 100644
> --- a/drivers/remoteproc/remoteproc_core.c
> +++ b/drivers/remoteproc/remoteproc_core.c
> @@ -1537,6 +1537,35 @@ static int rproc_fw_boot(struct rproc *rproc, const struct firmware *fw)
> return ret;
> }
>
> +static int rproc_set_loaded_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 (IS_ERR_OR_NULL(table_ptr)) {
> + if (!table_ptr)
> + ret = -EINVAL;
I did few tests on this showing that this approach does not cover all use cases.
The first one is a firmware without resource table. In this case table_ptr
should be null, or we have to consider the -ENOENT error as a non error usecase.
The second one, more tricky, is a firmware started by the remoteproc framework.
In this case the resource table address is retrieved from the ELF file by the
core part.
So if we detach and reattach rproc_get_loaded_rsc_table cannot return the
address. Look to me that we should have also an alocation of the clean_table in
rproc_start and then to keep the memory allocated until a shutdown.
That said regarding the complexity to re-attach, I wonder if it would not be
better to focus first on a simple detach, and address the reattachment in a
separate series, to move forward in stages.
Regards,
Arnaud
> + else
> + ret = PTR_ERR(table_ptr);
> +
> + dev_err(dev, "can't load resource table: %d\n", ret);
> + return ret;
> + }
> +
> + /*
> + * The resource table is already loaded in device memory, no need
> + * to work with a cached table.
> + */
> + 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.
> @@ -1556,6 +1585,12 @@ static int rproc_attach(struct rproc *rproc)
> return ret;
> }
>
> + ret = rproc_set_loaded_rsc_table(rproc);
> + if (ret) {
> + dev_err(dev, "can't load resource table: %d\n", ret);
> + goto disable_iommu;
> + }
> +
> /* reset max_notifyid */
> rproc->max_notifyid = -1;
>
> diff --git a/drivers/remoteproc/remoteproc_internal.h b/drivers/remoteproc/remoteproc_internal.h
> index c34002888d2c..4f73aac7e60d 100644
> --- a/drivers/remoteproc/remoteproc_internal.h
> +++ b/drivers/remoteproc/remoteproc_internal.h
> @@ -177,6 +177,16 @@ struct resource_table *rproc_find_loaded_rsc_table(struct rproc *rproc,
> return NULL;
> }
>
> +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)
> {
> diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h
> index 6b0a0ed30a03..51538a7d120d 100644
> --- a/include/linux/remoteproc.h
> +++ b/include/linux/remoteproc.h
> @@ -368,7 +368,9 @@ enum rsc_handling_status {
> * 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
> @@ -390,6 +392,8 @@ struct rproc_ops {
> 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);
>
