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. >>>> >>>> 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 >> >> >> >> >> >>
