On 4/1/20 4:53 PM, Mathieu Poirier wrote:
> 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()
Hmm, I want this to reflect a boolean answer for better code
flow/readability.
>
>
>>>
>>> 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?
Yeah OK. Its the combinations of ops (11 callbacks) plus sync states (3)
that kinda makes it hard to read the state-machine.
>
>>>
>>>> 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...
I see them as just decision flags for sync, it is not reflecting a state
like rproc->state. The rproc structure variable holds the current sync
flag state though.
>
>>
>> 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...
he he, indeed :)
>
>>>
>>>> + * 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.
Thanks,
Suman
>
>>>
>>> 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;
>>>> };
>>>>
>>>
>>
