| Message ID | 20210522000309.26134-3-s-anna@ti.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | K3 R5F & DSP IPC-only mode support | expand |
On Fri 21 May 19:03 CDT 2021, Suman Anna wrote: > The remoteproc core has support for both stopping and detaching a > remote processor that was attached to previously, through both the > remoteproc sysfs and cdev interfaces. The rproc_shutdown() though > unconditionally only uses the stop functionality at present. This > may not be the default desired functionality for all the remoteproc > platform drivers. > > Introduce a new rproc state flag 'detach_on_shutdown' that individual > remoteproc drivers can set to only allow detach in rproc_shutdown() > that would have been invoked when the driver is uninstalled, so that > remote processor continues to run undisturbed even after the driver > removal. > I dislike the introduction of knobs for everything and would much rather see that we define some sound defaults. Can we make shutdown just do detach() if that's supported otherwise stop(). This still allows userspace to explicitly stop the detachable remoteproc before shutdown, if for some reason that's what you want... Regards, Bjorn > Signed-off-by: Suman Anna <s-anna@ti.com> > --- > drivers/remoteproc/remoteproc_cdev.c | 7 +++++++ > drivers/remoteproc/remoteproc_core.c | 5 ++++- > drivers/remoteproc/remoteproc_sysfs.c | 6 ++++++ > include/linux/remoteproc.h | 3 +++ > 4 files changed, 20 insertions(+), 1 deletion(-) > > diff --git a/drivers/remoteproc/remoteproc_cdev.c b/drivers/remoteproc/remoteproc_cdev.c > index 0b8a84c04f76..473467711a09 100644 > --- a/drivers/remoteproc/remoteproc_cdev.c > +++ b/drivers/remoteproc/remoteproc_cdev.c > @@ -42,6 +42,13 @@ static ssize_t rproc_cdev_write(struct file *filp, const char __user *buf, size_ > rproc->state != RPROC_ATTACHED) > return -EINVAL; > > + if (rproc->state == RPROC_ATTACHED && > + rproc->detach_on_shutdown) { > + dev_err(&rproc->dev, > + "stop not supported for this rproc, use detach\n"); > + return -EINVAL; > + } > + > rproc_shutdown(rproc); > } else if (!strncmp(cmd, "detach", len)) { > if (rproc->state != RPROC_ATTACHED) > diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c > index 6019f46001c8..e8ab3eb41f00 100644 > --- a/drivers/remoteproc/remoteproc_core.c > +++ b/drivers/remoteproc/remoteproc_core.c > @@ -2074,7 +2074,10 @@ void rproc_shutdown(struct rproc *rproc) > if (!atomic_dec_and_test(&rproc->power)) > goto out; > > - ret = rproc_stop(rproc, false); > + if (rproc->detach_on_shutdown && rproc->state == RPROC_ATTACHED) > + ret = __rproc_detach(rproc); > + else > + ret = rproc_stop(rproc, false); > if (ret) { > atomic_inc(&rproc->power); > goto out; > diff --git a/drivers/remoteproc/remoteproc_sysfs.c b/drivers/remoteproc/remoteproc_sysfs.c > index ea8b89f97d7b..1785fbcb1075 100644 > --- a/drivers/remoteproc/remoteproc_sysfs.c > +++ b/drivers/remoteproc/remoteproc_sysfs.c > @@ -206,6 +206,12 @@ static ssize_t state_store(struct device *dev, > rproc->state != RPROC_ATTACHED) > return -EINVAL; > > + if (rproc->state == RPROC_ATTACHED && > + rproc->detach_on_shutdown) { > + dev_err(&rproc->dev, "stop not supported for this rproc, use detach\n"); > + return -EINVAL; > + } > + > rproc_shutdown(rproc); > } else if (sysfs_streq(buf, "detach")) { > if (rproc->state != RPROC_ATTACHED) > diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h > index 42a1f30e33a7..35ef921676a1 100644 > --- a/include/linux/remoteproc.h > +++ b/include/linux/remoteproc.h > @@ -530,6 +530,8 @@ struct rproc_dump_segment { > * @elf_machine: firmware ELF machine > * @cdev: character device of the rproc > * @cdev_put_on_release: flag to indicate if remoteproc should be shutdown on @char_dev release > + * @detach_on_shutdown: flag to indicate if remoteproc cannot be shutdown in > + * attached state and _only_ support detach > */ > struct rproc { > struct list_head node; > @@ -569,6 +571,7 @@ struct rproc { > u16 elf_machine; > struct cdev cdev; > bool cdev_put_on_release; > + bool detach_on_shutdown; > }; > > /** > -- > 2.30.1 >
Hi Bjorn, On 5/27/21 11:11 PM, Bjorn Andersson wrote: > On Fri 21 May 19:03 CDT 2021, Suman Anna wrote: > >> The remoteproc core has support for both stopping and detaching a >> remote processor that was attached to previously, through both the >> remoteproc sysfs and cdev interfaces. The rproc_shutdown() though >> unconditionally only uses the stop functionality at present. This >> may not be the default desired functionality for all the remoteproc >> platform drivers. >> >> Introduce a new rproc state flag 'detach_on_shutdown' that individual >> remoteproc drivers can set to only allow detach in rproc_shutdown() >> that would have been invoked when the driver is uninstalled, so that >> remote processor continues to run undisturbed even after the driver >> removal. >> > > I dislike the introduction of knobs for everything and would much rather > see that we define some sound defaults. Can we make shutdown just do > detach() if that's supported otherwise stop(). > I maybe missing your point, but the change in remoteproc_core below exactly does that, right? Are you saying drop the checks in remoteproc_cdev and remoteproc_sysfs? The asymmetry did bug me as well, but it is already existing even before this patch. I personally would have preferred a cleaner and symmetrical attach, start, stop, detach, but existing code has overloaded attach into start (keys off by RPROC_OFFLINE/RPROC_DETACHED) while introducing a separate detach from stop. I have retained the meaning of stop as shutdown from userspace interface perspective, but enforcing the checks for detach only remoteprocs. The logic in rproc_shutdown is for driver paths. > This still allows userspace to explicitly stop the detachable remoteproc > before shutdown, if for some reason that's what you want... This is the existing behavior and the difference between stop and detach. That behavior is maintained for remoteprocs not setting the detach_on_shutdown flag. I am only restricting the behavior for those that set it. Mathieu, Your thoughts on this? regards Suman > > Regards, > Bjorn > >> Signed-off-by: Suman Anna <s-anna@ti.com> >> --- >> drivers/remoteproc/remoteproc_cdev.c | 7 +++++++ >> drivers/remoteproc/remoteproc_core.c | 5 ++++- >> drivers/remoteproc/remoteproc_sysfs.c | 6 ++++++ >> include/linux/remoteproc.h | 3 +++ >> 4 files changed, 20 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/remoteproc/remoteproc_cdev.c b/drivers/remoteproc/remoteproc_cdev.c >> index 0b8a84c04f76..473467711a09 100644 >> --- a/drivers/remoteproc/remoteproc_cdev.c >> +++ b/drivers/remoteproc/remoteproc_cdev.c >> @@ -42,6 +42,13 @@ static ssize_t rproc_cdev_write(struct file *filp, const char __user *buf, size_ >> rproc->state != RPROC_ATTACHED) >> return -EINVAL; >> >> + if (rproc->state == RPROC_ATTACHED && >> + rproc->detach_on_shutdown) { >> + dev_err(&rproc->dev, >> + "stop not supported for this rproc, use detach\n"); >> + return -EINVAL; >> + } >> + >> rproc_shutdown(rproc); >> } else if (!strncmp(cmd, "detach", len)) { >> if (rproc->state != RPROC_ATTACHED) >> diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c >> index 6019f46001c8..e8ab3eb41f00 100644 >> --- a/drivers/remoteproc/remoteproc_core.c >> +++ b/drivers/remoteproc/remoteproc_core.c >> @@ -2074,7 +2074,10 @@ void rproc_shutdown(struct rproc *rproc) >> if (!atomic_dec_and_test(&rproc->power)) >> goto out; >> >> - ret = rproc_stop(rproc, false); >> + if (rproc->detach_on_shutdown && rproc->state == RPROC_ATTACHED) >> + ret = __rproc_detach(rproc); >> + else >> + ret = rproc_stop(rproc, false); >> if (ret) { >> atomic_inc(&rproc->power); >> goto out; >> diff --git a/drivers/remoteproc/remoteproc_sysfs.c b/drivers/remoteproc/remoteproc_sysfs.c >> index ea8b89f97d7b..1785fbcb1075 100644 >> --- a/drivers/remoteproc/remoteproc_sysfs.c >> +++ b/drivers/remoteproc/remoteproc_sysfs.c >> @@ -206,6 +206,12 @@ static ssize_t state_store(struct device *dev, >> rproc->state != RPROC_ATTACHED) >> return -EINVAL; >> >> + if (rproc->state == RPROC_ATTACHED && >> + rproc->detach_on_shutdown) { >> + dev_err(&rproc->dev, "stop not supported for this rproc, use detach\n"); >> + return -EINVAL; >> + } >> + >> rproc_shutdown(rproc); >> } else if (sysfs_streq(buf, "detach")) { >> if (rproc->state != RPROC_ATTACHED) >> diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h >> index 42a1f30e33a7..35ef921676a1 100644 >> --- a/include/linux/remoteproc.h >> +++ b/include/linux/remoteproc.h >> @@ -530,6 +530,8 @@ struct rproc_dump_segment { >> * @elf_machine: firmware ELF machine >> * @cdev: character device of the rproc >> * @cdev_put_on_release: flag to indicate if remoteproc should be shutdown on @char_dev release >> + * @detach_on_shutdown: flag to indicate if remoteproc cannot be shutdown in >> + * attached state and _only_ support detach >> */ >> struct rproc { >> struct list_head node; >> @@ -569,6 +571,7 @@ struct rproc { >> u16 elf_machine; >> struct cdev cdev; >> bool cdev_put_on_release; >> + bool detach_on_shutdown; >> }; >> >> /** >> -- >> 2.30.1 >>
Hey guys, On Fri, May 28, 2021 at 11:40:02AM -0500, Suman Anna wrote: > Hi Bjorn, > > On 5/27/21 11:11 PM, Bjorn Andersson wrote: > > On Fri 21 May 19:03 CDT 2021, Suman Anna wrote: > > > >> The remoteproc core has support for both stopping and detaching a > >> remote processor that was attached to previously, through both the > >> remoteproc sysfs and cdev interfaces. The rproc_shutdown() though > >> unconditionally only uses the stop functionality at present. This > >> may not be the default desired functionality for all the remoteproc > >> platform drivers. > >> > >> Introduce a new rproc state flag 'detach_on_shutdown' that individual > >> remoteproc drivers can set to only allow detach in rproc_shutdown() > >> that would have been invoked when the driver is uninstalled, so that > >> remote processor continues to run undisturbed even after the driver > >> removal. > >> > > > > I dislike the introduction of knobs for everything and would much rather > > see that we define some sound defaults. Can we make shutdown just do > > detach() if that's supported otherwise stop(). > > > > I maybe missing your point, but the change in remoteproc_core below exactly does > that, right? Are you saying drop the checks in remoteproc_cdev and remoteproc_sysfs? > > The asymmetry did bug me as well, but it is already existing even before this > patch. I personally would have preferred a cleaner and symmetrical attach, > start, stop, detach, but existing code has overloaded attach into start (keys > off by RPROC_OFFLINE/RPROC_DETACHED) while introducing a separate detach from > stop. I have retained the meaning of stop as shutdown from userspace interface > perspective, but enforcing the checks for detach only remoteprocs. > > The logic in rproc_shutdown is for driver paths. > > > This still allows userspace to explicitly stop the detachable remoteproc > > before shutdown, if for some reason that's what you want... > > This is the existing behavior and the difference between stop and detach. That > behavior is maintained for remoteprocs not setting the detach_on_shutdown flag. > I am only restricting the behavior for those that set it. > > Mathieu, > Your thoughts on this? Introducing knobs in such a way makes the code very difficult to understand and maintain. It is also a matter of time before another knob is introduced to modify the behavior of this knob. Function rproc_detach() is exported and should be used in the platform driver if the state of the remote processor mandates it. Function rproc_del() calls rproc_shutdown() but the latter will return immediately because of rproc->power. So calling rproc_detach() followed by rproc_del() will work as expected. The real fix is to de-couple rproc_shutdown from rproc_del() and do the right calls in the platform drivers using them. With regards to rproc_cdev_write(), the state of the remote processor is advertised in sysfs. As such it should be easy to write "stop" or "detach" to the character interface. If a command to stop the remote processor is not supported in a scenario then rproc_ops::stop should reflect that. If that is the case then rproc_shutdown() should be modified to return an error code, the same way rproc_detach() was done. > > regards > Suman > > > > > > > Regards, > > Bjorn > > > >> Signed-off-by: Suman Anna <s-anna@ti.com> > >> --- > >> drivers/remoteproc/remoteproc_cdev.c | 7 +++++++ > >> drivers/remoteproc/remoteproc_core.c | 5 ++++- > >> drivers/remoteproc/remoteproc_sysfs.c | 6 ++++++ > >> include/linux/remoteproc.h | 3 +++ > >> 4 files changed, 20 insertions(+), 1 deletion(-) > >> > >> diff --git a/drivers/remoteproc/remoteproc_cdev.c b/drivers/remoteproc/remoteproc_cdev.c > >> index 0b8a84c04f76..473467711a09 100644 > >> --- a/drivers/remoteproc/remoteproc_cdev.c > >> +++ b/drivers/remoteproc/remoteproc_cdev.c > >> @@ -42,6 +42,13 @@ static ssize_t rproc_cdev_write(struct file *filp, const char __user *buf, size_ > >> rproc->state != RPROC_ATTACHED) > >> return -EINVAL; > >> > >> + if (rproc->state == RPROC_ATTACHED && > >> + rproc->detach_on_shutdown) { > >> + dev_err(&rproc->dev, > >> + "stop not supported for this rproc, use detach\n"); > >> + return -EINVAL; > >> + } > >> + > >> rproc_shutdown(rproc); > >> } else if (!strncmp(cmd, "detach", len)) { > >> if (rproc->state != RPROC_ATTACHED) > >> diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c > >> index 6019f46001c8..e8ab3eb41f00 100644 > >> --- a/drivers/remoteproc/remoteproc_core.c > >> +++ b/drivers/remoteproc/remoteproc_core.c > >> @@ -2074,7 +2074,10 @@ void rproc_shutdown(struct rproc *rproc) > >> if (!atomic_dec_and_test(&rproc->power)) > >> goto out; > >> > >> - ret = rproc_stop(rproc, false); > >> + if (rproc->detach_on_shutdown && rproc->state == RPROC_ATTACHED) > >> + ret = __rproc_detach(rproc); > >> + else > >> + ret = rproc_stop(rproc, false); > >> if (ret) { > >> atomic_inc(&rproc->power); > >> goto out; > >> diff --git a/drivers/remoteproc/remoteproc_sysfs.c b/drivers/remoteproc/remoteproc_sysfs.c > >> index ea8b89f97d7b..1785fbcb1075 100644 > >> --- a/drivers/remoteproc/remoteproc_sysfs.c > >> +++ b/drivers/remoteproc/remoteproc_sysfs.c > >> @@ -206,6 +206,12 @@ static ssize_t state_store(struct device *dev, > >> rproc->state != RPROC_ATTACHED) > >> return -EINVAL; > >> > >> + if (rproc->state == RPROC_ATTACHED && > >> + rproc->detach_on_shutdown) { > >> + dev_err(&rproc->dev, "stop not supported for this rproc, use detach\n"); > >> + return -EINVAL; > >> + } > >> + > >> rproc_shutdown(rproc); > >> } else if (sysfs_streq(buf, "detach")) { > >> if (rproc->state != RPROC_ATTACHED) > >> diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h > >> index 42a1f30e33a7..35ef921676a1 100644 > >> --- a/include/linux/remoteproc.h > >> +++ b/include/linux/remoteproc.h > >> @@ -530,6 +530,8 @@ struct rproc_dump_segment { > >> * @elf_machine: firmware ELF machine > >> * @cdev: character device of the rproc > >> * @cdev_put_on_release: flag to indicate if remoteproc should be shutdown on @char_dev release > >> + * @detach_on_shutdown: flag to indicate if remoteproc cannot be shutdown in > >> + * attached state and _only_ support detach > >> */ > >> struct rproc { > >> struct list_head node; > >> @@ -569,6 +571,7 @@ struct rproc { > >> u16 elf_machine; > >> struct cdev cdev; > >> bool cdev_put_on_release; > >> + bool detach_on_shutdown; > >> }; > >> > >> /** > >> -- > >> 2.30.1 > >> >
diff --git a/drivers/remoteproc/remoteproc_cdev.c b/drivers/remoteproc/remoteproc_cdev.c index 0b8a84c04f76..473467711a09 100644 --- a/drivers/remoteproc/remoteproc_cdev.c +++ b/drivers/remoteproc/remoteproc_cdev.c @@ -42,6 +42,13 @@ static ssize_t rproc_cdev_write(struct file *filp, const char __user *buf, size_ rproc->state != RPROC_ATTACHED) return -EINVAL; + if (rproc->state == RPROC_ATTACHED && + rproc->detach_on_shutdown) { + dev_err(&rproc->dev, + "stop not supported for this rproc, use detach\n"); + return -EINVAL; + } + rproc_shutdown(rproc); } else if (!strncmp(cmd, "detach", len)) { if (rproc->state != RPROC_ATTACHED) diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c index 6019f46001c8..e8ab3eb41f00 100644 --- a/drivers/remoteproc/remoteproc_core.c +++ b/drivers/remoteproc/remoteproc_core.c @@ -2074,7 +2074,10 @@ void rproc_shutdown(struct rproc *rproc) if (!atomic_dec_and_test(&rproc->power)) goto out; - ret = rproc_stop(rproc, false); + if (rproc->detach_on_shutdown && rproc->state == RPROC_ATTACHED) + ret = __rproc_detach(rproc); + else + ret = rproc_stop(rproc, false); if (ret) { atomic_inc(&rproc->power); goto out; diff --git a/drivers/remoteproc/remoteproc_sysfs.c b/drivers/remoteproc/remoteproc_sysfs.c index ea8b89f97d7b..1785fbcb1075 100644 --- a/drivers/remoteproc/remoteproc_sysfs.c +++ b/drivers/remoteproc/remoteproc_sysfs.c @@ -206,6 +206,12 @@ static ssize_t state_store(struct device *dev, rproc->state != RPROC_ATTACHED) return -EINVAL; + if (rproc->state == RPROC_ATTACHED && + rproc->detach_on_shutdown) { + dev_err(&rproc->dev, "stop not supported for this rproc, use detach\n"); + return -EINVAL; + } + rproc_shutdown(rproc); } else if (sysfs_streq(buf, "detach")) { if (rproc->state != RPROC_ATTACHED) diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h index 42a1f30e33a7..35ef921676a1 100644 --- a/include/linux/remoteproc.h +++ b/include/linux/remoteproc.h @@ -530,6 +530,8 @@ struct rproc_dump_segment { * @elf_machine: firmware ELF machine * @cdev: character device of the rproc * @cdev_put_on_release: flag to indicate if remoteproc should be shutdown on @char_dev release + * @detach_on_shutdown: flag to indicate if remoteproc cannot be shutdown in + * attached state and _only_ support detach */ struct rproc { struct list_head node; @@ -569,6 +571,7 @@ struct rproc { u16 elf_machine; struct cdev cdev; bool cdev_put_on_release; + bool detach_on_shutdown; }; /**
The remoteproc core has support for both stopping and detaching a remote processor that was attached to previously, through both the remoteproc sysfs and cdev interfaces. The rproc_shutdown() though unconditionally only uses the stop functionality at present. This may not be the default desired functionality for all the remoteproc platform drivers. Introduce a new rproc state flag 'detach_on_shutdown' that individual remoteproc drivers can set to only allow detach in rproc_shutdown() that would have been invoked when the driver is uninstalled, so that remote processor continues to run undisturbed even after the driver removal. Signed-off-by: Suman Anna <s-anna@ti.com> --- drivers/remoteproc/remoteproc_cdev.c | 7 +++++++ drivers/remoteproc/remoteproc_core.c | 5 ++++- drivers/remoteproc/remoteproc_sysfs.c | 6 ++++++ include/linux/remoteproc.h | 3 +++ 4 files changed, 20 insertions(+), 1 deletion(-)