On Mon, Mar 30, 2020 at 05:49:11PM -0500, Suman Anna wrote:
> On 3/30/20 5:46 PM, Suman Anna wrote:
> > Hi Mathieu,
> >
> > On 3/24/20 4:45 PM, Mathieu Poirier wrote:
> >> Add a new rproc_ops sync_ops to support use cases where the remoteproc
> >> core is synchronisting with the MCU. When exactly to use the sync_ops is
> >
> > typo on syschronisting..
> >
> >> directed by the states in struct rproc_sync_states.
> >>
> >> Signed-off-by: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
> >> ---
> >> drivers/remoteproc/remoteproc_debugfs.c | 31 ++++++++++++++++++++++++
> >> drivers/remoteproc/remoteproc_internal.h | 5 ++++
> >> include/linux/remoteproc.h | 23 +++++++++++++++++-
> >> 3 files changed, 58 insertions(+), 1 deletion(-)
> >>
> >> diff --git a/drivers/remoteproc/remoteproc_debugfs.c b/drivers/remoteproc/remoteproc_debugfs.c
> >> index dd93cf04e17f..187bcc67f997 100644
> >> --- a/drivers/remoteproc/remoteproc_debugfs.c
> >> +++ b/drivers/remoteproc/remoteproc_debugfs.c
> >> @@ -311,6 +311,35 @@ static const struct file_operations rproc_carveouts_ops = {
> >> .release = single_release,
> >> };
> >>
> >> +/* Expose synchronisation states via debugfs */
> >> +static int rproc_sync_states_show(struct seq_file *seq, void *p)
> >> +{
> >> + struct rproc *rproc = seq->private;
> >> +
> >> + seq_printf(seq, "Sync with MCU: %s\n",
> >> + rproc->sync_with_mcu ? "true" : "false");
> >> + seq_printf(seq, "On init: %s\n",
> >> + rproc->sync_states->on_init ? "true" : "false");
> >> + seq_printf(seq, "After stop: %s\n",
> >> + rproc->sync_states->after_stop ? "true" : "false");
> >> + seq_printf(seq, "After crash: %s\n",
> >> + rproc->sync_states->after_crash ? "true" : "false");
> >> +
> >> + return 0;
> >> +}
> >> +
> >> +static int rproc_sync_states_open(struct inode *inode, struct file *file)
> >> +{
> >> + return single_open(file, rproc_sync_states_show, inode->i_private);
> >> +}
> >> +
> >> +static const struct file_operations rproc_sync_states_ops = {
> >> + .open = rproc_sync_states_open,
> >> + .read = seq_read,
> >> + .llseek = seq_lseek,
> >> + .release = single_release,
> >> +};
> >> +
> >> void rproc_remove_trace_file(struct dentry *tfile)
> >> {
> >> debugfs_remove(tfile);
> >> @@ -357,6 +386,8 @@ void rproc_create_debug_dir(struct rproc *rproc)
> >> rproc, &rproc_rsc_table_ops);
> >> debugfs_create_file("carveout_memories", 0400, rproc->dbg_dir,
> >> rproc, &rproc_carveouts_ops);
> >> + debugfs_create_file("sync_states", 0400, rproc->dbg_dir,
> >> + rproc, &rproc_sync_states_ops);
> >> }
> >>
> >> void __init rproc_init_debugfs(void)
> >> diff --git a/drivers/remoteproc/remoteproc_internal.h b/drivers/remoteproc/remoteproc_internal.h
> >> index 493ef9262411..5c93de5e00bb 100644
> >> --- a/drivers/remoteproc/remoteproc_internal.h
> >> +++ b/drivers/remoteproc/remoteproc_internal.h
> >> @@ -63,6 +63,11 @@ struct resource_table *rproc_elf_find_loaded_rsc_table(struct rproc *rproc,
> >> struct rproc_mem_entry *
> >> rproc_find_carveout_by_name(struct rproc *rproc, const char *name, ...);
> >>
> >> +static inline bool rproc_sync_with_mcu(struct rproc *rproc)
> >> +{
> >> + return rproc->sync_with_mcu;
> >> +}
> >> +
> >
> > Since you are using this mostly for checking and as a boolean, I suggest
> > you rename this appropriately, something like rproc_needs_sync,
> > rproc_has_sync or rproc_uses_sync().
I will rename to rproc_syncing_with_rproc()
> >
> > And I am wondering if it is actually better to introduce the sync state
> > to check against here, rather than using the stored sync state and
> > return. The current way makes it confusing to read the state machine.
I decided to proceed this way because there may not be a direct correlation
between the current synchronisation state and the location of the check itself.
for instance, in firmware_show(), what sync state should be key on?
> >
> >> static inline
> >> int rproc_fw_sanity_check(struct rproc *rproc, const struct firmware *fw)
> >> {
> >> diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h
> >> index 16ad66683ad0..d115e47d702d 100644
> >> --- a/include/linux/remoteproc.h
> >> +++ b/include/linux/remoteproc.h
> >> @@ -353,6 +353,21 @@ enum rsc_handling_status {
> >> RSC_IGNORED = 1,
> >> };
> >>
> >> +/**
> >> + * struct rproc_sync_states - platform specific states indicating which
> >> + * rproc_ops to use at specific times during
> >> + * the MCU lifecycle.
> >> + * @on_init: true if synchronising with MCU at system initialisation time
> >> + * @after_stop: true if synchronising with MCU after stopped from the
> >> + * command line
> >> + * @after_crash: true if synchonising with MCU after the MCU has crashed
> >> + */
> >> +struct rproc_sync_states {
> >> + bool on_init;
> >> + bool after_stop;
> >> + bool after_crash;
> >> +};
> >> +
> >
> > Overall, this patch can move down the order, and better to add it in
> > the patches where you actually introduce these code. And the debugfs
> > pieces can be added as a separate patch by itself.
>
> Also, actually sounds more like flags than states..
I thought about this in terms of "states" in which a decision should be made.
I'm not sure those are flags...
>
> regards
> Suman
>
> >
> >> /**
> >> * struct rproc_ops - platform-specific device handlers
> >> * @start: power on the device and boot it
> >> @@ -456,6 +471,9 @@ struct rproc_dump_segment {
> >> * @firmware: name of firmware file to be loaded
> >> * @priv: private data which belongs to the platform-specific rproc module
> >> * @ops: platform-specific start/stop rproc handlers
> >> + * @sync_ops: paltform-specific start/stop rproc handlers when
> >
> > typo on platform
No matter how many times you read your own code, there's always something like
this that escapes...
> >
> >> + * synchronising with a remote processor.
> >> + * @sync_states: Determine the rproc_ops to choose in specific states.
> >> * @dev: virtual device for refcounting and common remoteproc behavior
> >> * @power: refcount of users who need this rproc powered up
> >> * @state: state of the device
> >> @@ -479,6 +497,7 @@ struct rproc_dump_segment {
> >> * @table_sz: size of @cached_table
> >> * @has_iommu: flag to indicate if remote processor is behind an MMU
> >> * @auto_boot: flag to indicate if remote processor should be auto-started
> >> + * @sync_with_mcu: true if currently synchronising with MCU
> >> * @dump_segments: list of segments in the firmware
> >> * @nb_vdev: number of vdev currently handled by rproc
> >> */
> >> @@ -488,7 +507,8 @@ struct rproc {
> >> const char *name;
> >> char *firmware;
> >> void *priv;
> >> - struct rproc_ops *ops;
> >> + struct rproc_ops *ops, *sync_ops;
> >
> > Nothing wrong with this, but prefer to have the new variable in a new
> > line for better readability.
Sure thing.
> >
> > regards
> > Suman
> >
> >> + struct rproc_sync_states *sync_states;
> >> struct device dev;
> >> atomic_t power;
> >> unsigned int state;
> >> @@ -512,6 +532,7 @@ struct rproc {
> >> size_t table_sz;
> >> bool has_iommu;
> >> bool auto_boot;
> >> + bool sync_with_mcu;
> >> struct list_head dump_segments;
> >> int nb_vdev;
> >> };
> >>
> >
>
