On Wed, Feb 03, 2021 at 08:58:15AM +0100, Arnaud POULIQUEN wrote: > > > On 2/2/21 11:42 PM, Mathieu Poirier wrote: > > On Tue, Feb 02, 2021 at 09:54:13AM +0100, Arnaud POULIQUEN wrote: > >> > >> > >> On 2/2/21 1:49 AM, Mathieu Poirier wrote: > >>> On Wed, Jan 27, 2021 at 10:21:24AM +0100, Arnaud POULIQUEN wrote: > >>>> Hi Mathieu > >>>> > >>>> On 12/18/20 6:32 PM, Mathieu Poirier wrote: > >>>>> Following the work done here [1], this set provides support for the > >>>>> remoteproc core to release resources associated with a remote processor > >>>>> without having to switch it off. That way a platform driver can be removed > >>>>> or the application processor power cycled while the remote processor is > >>>>> still operating. > >>>>> > >>>>> Of special interest in this series are patches 5 and 6 where getting the > >>>>> address of the resource table installed by an eternal entity if moved to > >>>>> the core. This is to support scenarios where a remote process has been > >>>>> booted by the core but is being detached. To re-attach the remote > >>>>> processor, the address of the resource table needs to be known at a later > >>>>> time than the platform driver's probe() function. > >>>>> > >>>>> Applies cleanly on v5.10 > >>>>> > >>>>> Thanks, > >>>>> Mathieu > >>>>> > >>>>> [1]. https://lkml.org/lkml/2020/7/14/1600 > >>>>> > >>>>> ---- > >>>>> New for v4: > >>>>> - Made binding description OS agnostic (Rob) > >>>>> - Added functionality to set the external resource table in the core > >>>>> - Fixed a crash when detaching (Arnaud) > >>>>> - Fixed error code propagation in rproc_cdev_relase() and rproc_del() (Arnaud) > >>>>> - Added RB tags > >>>> > >>>> > >>>> I tested you series, attach and detach is working well. > >>>> > >>>> Then I faced issue when tried to re-attach after a detach. > >>>> > >>> > >>> Right, in this case don't expect the re-attach to work properly because function > >>> stm32_rproc_detach() does not exist. As such the M4 doesn't put itself back > >>> in "wait-for-attach" mode as it does when booted by the boot loader. If I > >>> remember correctly we talked about that during an earlier conversation and we > >>> agreed FW support would be needed to properly test the re-attach. > >> > >> Yes you are right the remote firmware needs to be inform about the detach, and > >> this is the purpose of the detach ops. > >> But also some actions are missing on local side as some resources have also to > >> be reinitialized as described in my previous mail. > >> For instance the resource table is handled by the remoteproc framework. The > >> remote firmware should only have a read access to this table. > >> > >>> > >>>> But I don't know if this feature has to be supported in this step. > >>>> > >>>> The 2 issues I found are: > >>>> > >>>> 1) memory carveouts are released on detach so need to be reinitialized. > >>>> The use of prepare/unprepare for the attach and detach would solve the issue but > >>>> probably need to add parameter to differentiate a start/stop from a attach/detach. > > > > I am in agreement with you assesment and the patch you have proposed to fix it. > > Right now carveouts are properly handled between start and stop operations > > because their parsing and allocation is done as part for ops:parse_fw(), which > > is called for each iteration. Moving the parsing and allocation to > > rproc_prepare_device() ends up doing the same thing. > > > > I am not sure we absolutely need an extra parameter to differentiate between > > start/stop and attach/detach. Typically the rproc_prepare_device() is used to > > do some kind of setup like providing power to a memory bank. I suppose that if > > a memory bank is already powered by the boot loader, asking to power it up again > > won't do anything. > > > > As such I suggest we keep the parameters as they are now. We can revisit if a > > use case comes up at a later time. > > > > Your suggestion sound good to me. > > >>>> > >>>> 2) The vrings in the loaded resource table (so no cached) has to be properly > >>>> reinitialized. In rproc_free_vring the vring da is set to 0 that is then > >>>> considered as a fixed address. > >>>> > >>>> Here is a fix which works on the stm32 platform > >>>> > >>>> @@ -425,7 +425,7 @@ void rproc_free_vring(struct rproc_vring *rvring) > >>>> */ > >>>> if (rproc->table_ptr) { > >>>> rsc = (void *)rproc->table_ptr + rvring->rvdev->rsc_offset; > >>>> - rsc->vring[idx].da = 0; > >>>> + rsc->vring[idx].da = FW_RSC_ADDR_ANY; > >>>> rsc->vring[idx].notifyid = -1; > >>>> } > >>>> } > > > > I see why this could be needed. I initially assumed the remote processor would > > install a new resource table in memory upon receiving notification the core is > > going away. But upon reflection the remote processor may not even have access > > to the image it is running. > > The risk here is that both processors try to access this table at the same time. > > > > > Let me think about this further - I want to make sure we don't introduce a > > regression for current implementations. > > Just a precision: the vring DA can be fixed by the coprocessor firmware to > impose the address, my patch is not sufficent in such case for the reattachment. > That's why i suggested a copy of the resource table before updating it. > > Thanks, > Arnaud > > > > >>> > >>> In light of the above let me know if these two issues are still relevant. If > >>> so I'll investigate further. > >> > >> To highlight the issue just test attach/detach/attch with a firmware that > >> implements a RPMsg communication. On the second attach the virtio framework is > >> not properly restarted. > >> > >> Then please find at the end of the mail 3 patches for test I added on top of > >> your series,that allow me to reattach. Of course the RPMsg channels are not > >> re-created as i don't implement the remote FW part, but the Linux virtio and > >> RPmsg frameworks are restarted. > >> > >> - [PATCH 1/3] remoteproc: stm32: add capability to detach from the remoteproc > >> => Add a dummy function in stm32_rproc for test. > >> - [PATCH 2/3] remoteproc: Add prepare/unprepare for attach detach > >> => Add prepare/unprepare on attach/detach + implement attach in stm32mp1 to > >> reinitialize the memory region that as been cleaned on detach. > >> - [PATCH 3/3] remoteproc: virtio: set to vring address to FW_RSC_ADDR_ANY on free > >> => Reinitialize the vring addresses on detach. For this one a better > >> implementation would be to use a cached resource table to fully > >> reinitialize it on re-attach. > >> > >> Thanks, > >> Arnaud > >> > >>> > >>> Thanks, > >>> Mathieu > >>> > >>>> > >>>> Here, perhaps a better alternative would be to make a cached copy on attach > >>>> before updating it. On the next attach, the cached copy would be copied as it is > >>>> done in rproc_start. I've been staring long and hard at this code and I don't see another way than keeping a clean copy of the resource table as you mentionned above. And managing that table isn't trivial either. I am working on a solution, something that I should be able to publish by the end of the week. Thanks, Mathieu > >>>> > >>>> Thanks, > >>>> Arnaud > >>>> > >>>> > >>>>> > >>>>> Mathieu Poirier (17): > >>>>> dt-bindings: remoteproc: Add bindind to support autonomous processors > >>>>> remoteproc: Re-check state in rproc_shutdown() > >>>>> remoteproc: Remove useless check in rproc_del() > >>>>> remoteproc: Rename function rproc_actuate() > >>>>> remoteproc: Add new get_loaded_rsc_table() remoteproc operation > >>>>> remoteproc: stm32: Move resource table setup to rproc_ops > >>>>> remoteproc: Add new RPROC_ATTACHED state > >>>>> remoteproc: Properly represent the attached state > >>>>> remoteproc: Properly deal with a kernel panic when attached > >>>>> remoteproc: Add new detach() remoteproc operation > >>>>> remoteproc: Introduce function __rproc_detach() > >>>>> remoteproc: Introduce function rproc_detach() > >>>>> remoteproc: Add return value to function rproc_shutdown() > >>>>> remoteproc: Properly deal with a stop request when attached > >>>>> remoteproc: Properly deal with a start request when attached > >>>>> remoteproc: Properly deal with detach request > >>>>> remoteproc: Refactor rproc delete and cdev release path > >>>>> > >>>>> .../bindings/remoteproc/remoteproc-core.yaml | 27 +++ > >>>>> drivers/remoteproc/remoteproc_cdev.c | 32 ++- > >>>>> drivers/remoteproc/remoteproc_core.c | 211 +++++++++++++++--- > >>>>> drivers/remoteproc/remoteproc_internal.h | 8 + > >>>>> drivers/remoteproc/remoteproc_sysfs.c | 20 +- > >>>>> drivers/remoteproc/stm32_rproc.c | 147 ++++++------ > >>>>> include/linux/remoteproc.h | 24 +- > >>>>> 7 files changed, 344 insertions(+), 125 deletions(-) > >>>>> create mode 100644 Documentation/devicetree/bindings/remoteproc/remoteproc-core.yaml > >>>>> > >> > >> Subject: [PATCH 1/3] remoteproc: stm32: add capability to detach from the > >> remoteproc > >> > >> Add a dummy function to allow to detach. No specific action is needed > >> > >> Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@xxxxxxxxxxx> > >> --- > >> drivers/remoteproc/stm32_rproc.c | 7 +++++++ > >> 1 file changed, 7 insertions(+) > >> > >> diff --git a/drivers/remoteproc/stm32_rproc.c b/drivers/remoteproc/stm32_rproc.c > >> index 2c949725b91e..b325d28f627c 100644 > >> --- a/drivers/remoteproc/stm32_rproc.c > >> +++ b/drivers/remoteproc/stm32_rproc.c > >> @@ -590,6 +590,12 @@ static int stm32_rproc_attach(struct rproc *rproc) > >> return reset_control_assert(ddata->hold_boot); > >> } > >> > >> +static int stm32_rproc_detach(struct rproc *rproc) > >> +{ > >> + /* Nothing to do but ops mandatory to support the detach feature */ > >> + return 0; > >> +} > >> + > >> static int stm32_rproc_stop(struct rproc *rproc) > >> { > >> struct stm32_rproc *ddata = rproc->priv; > >> @@ -712,6 +718,7 @@ static struct rproc_ops st_rproc_ops = { > >> .start = stm32_rproc_start, > >> .stop = stm32_rproc_stop, > >> .attach = stm32_rproc_attach, > >> + .detach = stm32_rproc_detach, > >> .kick = stm32_rproc_kick, > >> .load = rproc_elf_load_segments, > >> .parse_fw = stm32_rproc_parse_fw, > >> -- > >> 2.17.1 > >> > >> > >> ------------------------------------------------------------------------ > >> > >> > >> Subject: [PATCH 2/3] remoteproc: Add prepare/unprepare for attach detach > >> > >> Some actions such as memory resources reallocation are needed when try > >> to reattach. Use the prepare ops for these actions. > >> > >> Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@xxxxxxxxxxx> > >> --- > >> drivers/remoteproc/remoteproc_core.c | 14 ++++++++++++++ > >> drivers/remoteproc/stm32_rproc.c | 14 +++++++------- > >> 2 files changed, 21 insertions(+), 7 deletions(-) > >> > >> diff --git a/drivers/remoteproc/remoteproc_core.c > >> b/drivers/remoteproc/remoteproc_core.c > >> index f1f51ad1a1d6..f177561b8863 100644 > >> --- a/drivers/remoteproc/remoteproc_core.c > >> +++ b/drivers/remoteproc/remoteproc_core.c > >> @@ -1557,6 +1557,13 @@ static int rproc_attach(struct rproc *rproc) > >> return ret; > >> } > >> > >> + /* Prepare rproc for firmware loading if needed */ > >> + ret = rproc_prepare_device(rproc); > >> + if (ret) { > >> + dev_err(dev, "can't prepare rproc %s: %d\n", rproc->name, ret); > >> + goto disable_iommu; > >> + } > >> + > >> ret = rproc_get_loaded_rsc_table(rproc); > >> if (ret) { > >> dev_err(dev, "can't load resource table: %d\n", ret); > >> @@ -1990,6 +1997,13 @@ int rproc_detach(struct rproc *rproc) > >> /* clean up all acquired resources */ > >> rproc_resource_cleanup(rproc); > >> > >> + /* Release HW resources if needed */ > >> + ret = rproc_unprepare_device(rproc); > >> + if (ret) { > >> + atomic_inc(&rproc->power); > >> + goto out; > >> + } > >> + > >> rproc_disable_iommu(rproc); > >> > >> /* > >> diff --git a/drivers/remoteproc/stm32_rproc.c b/drivers/remoteproc/stm32_rproc.c > >> index b325d28f627c..bf50d79b1f09 100644 > >> --- a/drivers/remoteproc/stm32_rproc.c > >> +++ b/drivers/remoteproc/stm32_rproc.c > >> @@ -413,9 +413,6 @@ static int stm32_rproc_parse_fw(struct rproc *rproc, const > >> struct firmware *fw) > >> struct stm32_rproc *ddata = rproc->priv; > >> int ret; > >> > >> - ret = stm32_rproc_parse_memory_regions(rproc); > >> - if (ret) > >> - return ret; > >> > >> if (ddata->trproc) > >> ret = rproc_tee_get_rsc_table(ddata->trproc); > >> @@ -580,6 +577,12 @@ static int stm32_rproc_start(struct rproc *rproc) > >> > >> return reset_control_assert(ddata->hold_boot); > >> } > >> +static int stm32_rproc_prepare(struct rproc *rproc) > >> +{ > >> + dev_err(&rproc->dev, "%s: %d\n", __func__, __LINE__); > >> + > >> + return stm32_rproc_parse_memory_regions(rproc); > >> +} > >> > >> static int stm32_rproc_attach(struct rproc *rproc) > >> { > >> @@ -717,6 +720,7 @@ static int stm32_rproc_get_loaded_rsc_table(struct rproc *rproc) > >> static struct rproc_ops st_rproc_ops = { > >> .start = stm32_rproc_start, > >> .stop = stm32_rproc_stop, > >> + .prepare = stm32_rproc_prepare, > >> .attach = stm32_rproc_attach, > >> .detach = stm32_rproc_detach, > >> .kick = stm32_rproc_kick, > >> @@ -921,10 +925,6 @@ static int stm32_rproc_probe(struct platform_device *pdev) > >> > >> if (state == M4_STATE_CRUN) { > >> rproc->state = RPROC_DETACHED; > >> - > >> - ret = stm32_rproc_parse_memory_regions(rproc); > >> - if (ret) > >> - goto free_resources; > >> } > >> > >> rproc->has_iommu = false; > >> -- > >> 2.17.1 > >> > >> > >> ------------------------------------------------------------------------ > >> > >> Subject: [PATCH 3/3] remoteproc: virtio: set to vring address to > >> FW_RSC_ADDR_ANY on free > >> > >> The resource table vring structure is cleaned on free. But value is set > >> to 0. This value is considered as a valid address. Set the value > >> to FW_RSC_ADDR_ANY instead. > >> This is needed to allow to reattach to an autonomous firmware. > >> An alternative would be to save the resource table before updating it. > >> On free the value would be reset to initial value. > >> > >> Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@xxxxxxxxxxx> > >> --- > >> drivers/remoteproc/remoteproc_core.c | 2 +- > >> 1 file changed, 1 insertion(+), 1 deletion(-) > >> > >> diff --git a/drivers/remoteproc/remoteproc_core.c > >> b/drivers/remoteproc/remoteproc_core.c > >> index f177561b8863..5b5de4db3981 100644 > >> --- a/drivers/remoteproc/remoteproc_core.c > >> +++ b/drivers/remoteproc/remoteproc_core.c > >> @@ -425,7 +425,7 @@ void rproc_free_vring(struct rproc_vring *rvring) > >> */ > >> if (rproc->table_ptr) { > >> rsc = (void *)rproc->table_ptr + rvring->rvdev->rsc_offset; > >> - rsc->vring[idx].da = 0; > >> + rsc->vring[idx].da = FW_RSC_ADDR_ANY; > >> rsc->vring[idx].notifyid = -1; > >> } > >> } > >> -- > >> 2.17.1 > >> > >> > >> > >> > >> > >>
