On Thu, 27 Nov 2025 at 03:33, Beleswar Prasad Padhi <[email protected]> wrote: > > Hi Patrick, Mathieu, > > On 27/11/25 02:11, Patrick Oppenlander wrote: > > On Tue, 25 Nov 2025 at 19:39, Beleswar Padhi <[email protected]> wrote: > >> From: Richard Genoud <[email protected]> > >> > >> Introduce software IPC handshake between the host running Linux and the > >> remote processors to gracefully stop/reset the remote core. > >> > >> Upon a stop request, remoteproc driver sends a RP_MBOX_SHUTDOWN mailbox > >> message to the remotecore. > >> The remote core is expected to: > >> - relinquish all the resources acquired through Device Manager (DM) > >> - disable its interrupts > >> - send back a mailbox acknowledgment RP_MBOX_SHUDOWN_ACK > >> - enter WFI state. > > What happens if the remote core is unable to action the shutdown > > request > > > We abort the shutdown sequence if the remoteproc does not respond with > an ACK within the timeout assuming rproc is busy doing some work. > > > (maybe it has crashed). > > > remoteproc core has the infra to handle rproc crash. It initiates a > recovery mechanism by stopping and starting the rproc with the same > firmware. > > Are you suggesting that we check if rproc_stop() is invoked from a > recovery context, and forcefully reset the rproc without sending/waiting > for SHUTDOWN msg as a crashed core can't respond to mbox irqs? > > > > > Is there a way to cleanup resources which the remote core allocated > > without rebooting the whole system? > > For SW resources (like mem, vdev): Yes > However, I feel this is currently missing in rproc core. We should be > making a call to rproc_resource_cleanup() in rproc_boot_recovery()'s > error paths and in rproc_crash_handler_work() in case of subsequent > crashes. > > ^^ Mathieu, thoughts about the above? >
Given the backlog of patchsets I have to review, Plumbers in two weeks and the December holidays, I won't be able to look at this issue before January. Thanks, Mathieu > For HW resources: No > In TI Device Manager (DM) firmware, only the entity which requested a > resource can relinquish it, no other host can do that cleanup on behalf > of that entity. So, we can't do much here. > > Thanks, > Beleswar > > > > > Patrick > > > >> Meanwhile, the K3 remoteproc driver does: > >> - wait for the RP_MBOX_SHUTDOWN_ACK from the remote core > >> - wait for the remoteproc to enter WFI state > >> - reset the remote core through device manager > >> > >> Based on work from: Hari Nagalla <[email protected]> > >> > >> Signed-off-by: Richard Genoud <[email protected]> > >> [[email protected]: Extend support to all rprocs] > >> Signed-off-by: Beleswar Padhi <[email protected]> > >> --- > >> v2: Changelog: > >> 1. Extend graceful shutdown support for all rprocs (R5, DSP, M4) > >> 2. Halt core only if SHUTDOWN_ACK is received from rproc and it has > >> entered WFI state. > >> 3. Convert return type of is_core_in_wfi() to bool. Works better with > >> readx_poll_timeout() condition. > >> 4. Cast RP_MBOX_SHUTDOWN to uintptr_t to suppress compiler warnings > >> when void* is 64 bit. > >> 5. Wrapped Graceful shutdown code in the form of notify_shutdown_rproc > >> function. > >> 6. Updated commit message to fix minor typos and such. > >> > >> Link to v1: > >> https://lore.kernel.org/all/[email protected]/ > >> > >> Testing done: > >> 1. Tested Boot across all TI K3 EVM/SK boards. > >> 2. Tested IPC on all TI K3 J7* EVM/SK boards (& AM62x SK). > >> 4. Tested R5 rprocs can now be shutdown and powered back on > >> from userspace. > >> 3. Tested that each patch in the series generates no new > >> warnings/errors. > >> > >> drivers/remoteproc/omap_remoteproc.h | 9 ++- > >> drivers/remoteproc/ti_k3_common.c | 72 +++++++++++++++++++++++ > >> drivers/remoteproc/ti_k3_common.h | 4 ++ > >> drivers/remoteproc/ti_k3_dsp_remoteproc.c | 2 + > >> drivers/remoteproc/ti_k3_m4_remoteproc.c | 2 + > >> drivers/remoteproc/ti_k3_r5_remoteproc.c | 5 ++ > >> 6 files changed, 93 insertions(+), 1 deletion(-) > >> > >> diff --git a/drivers/remoteproc/omap_remoteproc.h > >> b/drivers/remoteproc/omap_remoteproc.h > >> index 828e13256c023..c008f11fa2a43 100644 > >> --- a/drivers/remoteproc/omap_remoteproc.h > >> +++ b/drivers/remoteproc/omap_remoteproc.h > >> @@ -42,6 +42,11 @@ > >> * @RP_MBOX_SUSPEND_CANCEL: a cancel suspend response from a remote > >> processor > >> * on a suspend request > >> * > >> + * @RP_MBOX_SHUTDOWN: shutdown request for the remote processor > >> + * > >> + * @RP_MBOX_SHUTDOWN_ACK: successful response from remote processor for a > >> + * shutdown request. The remote processor should be in WFI state short > >> after. > >> + * > >> * Introduce new message definitions if any here. > >> * > >> * @RP_MBOX_END_MSG: Indicates end of known/defined messages from remote > >> core > >> @@ -59,7 +64,9 @@ enum omap_rp_mbox_messages { > >> RP_MBOX_SUSPEND_SYSTEM = 0xFFFFFF11, > >> RP_MBOX_SUSPEND_ACK = 0xFFFFFF12, > >> RP_MBOX_SUSPEND_CANCEL = 0xFFFFFF13, > >> - RP_MBOX_END_MSG = 0xFFFFFF14, > >> + RP_MBOX_SHUTDOWN = 0xFFFFFF14, > >> + RP_MBOX_SHUTDOWN_ACK = 0xFFFFFF15, > >> + RP_MBOX_END_MSG = 0xFFFFFF16, > >> }; > >> > >> #endif /* _OMAP_RPMSG_H */ > >> diff --git a/drivers/remoteproc/ti_k3_common.c > >> b/drivers/remoteproc/ti_k3_common.c > >> index 56b71652e449f..5d469f65115c3 100644 > >> --- a/drivers/remoteproc/ti_k3_common.c > >> +++ b/drivers/remoteproc/ti_k3_common.c > >> @@ -18,7 +18,9 @@ > >> * Hari Nagalla <[email protected]> > >> */ > >> > >> +#include <linux/delay.h> > >> #include <linux/io.h> > >> +#include <linux/iopoll.h> > >> #include <linux/mailbox_client.h> > >> #include <linux/module.h> > >> #include <linux/of_address.h> > >> @@ -69,6 +71,10 @@ void k3_rproc_mbox_callback(struct mbox_client *client, > >> void *data) > >> case RP_MBOX_ECHO_REPLY: > >> dev_info(dev, "received echo reply from %s\n", > >> rproc->name); > >> break; > >> + case RP_MBOX_SHUTDOWN_ACK: > >> + dev_dbg(dev, "received shutdown_ack from %s\n", > >> rproc->name); > >> + complete(&kproc->shutdown_complete); > >> + break; > >> default: > >> /* silently handle all other valid messages */ > >> if (msg >= RP_MBOX_READY && msg < RP_MBOX_END_MSG) > >> @@ -188,6 +194,67 @@ int k3_rproc_request_mbox(struct rproc *rproc) > >> } > >> EXPORT_SYMBOL_GPL(k3_rproc_request_mbox); > >> > >> +/** > >> + * is_core_in_wfi - Utility function to check core status > >> + * @kproc: remote core pointer used for checking core status > >> + * > >> + * This utility function is invoked by the shutdown sequence to ensure > >> + * the remote core is in wfi, before asserting a reset. > >> + */ > >> +bool is_core_in_wfi(struct k3_rproc *kproc) > >> +{ > >> + int ret; > >> + u64 boot_vec; > >> + u32 cfg, ctrl, stat; > >> + > >> + ret = ti_sci_proc_get_status(kproc->tsp, &boot_vec, &cfg, &ctrl, > >> &stat); > >> + if (ret) > >> + return false; > >> + > >> + return (bool)(stat & PROC_BOOT_STATUS_FLAG_CPU_WFI); > >> +} > >> +EXPORT_SYMBOL_GPL(is_core_in_wfi); > >> + > >> +/** > >> + * notify_shutdown_rproc - Prepare the remoteproc for a shutdown > >> + * @kproc: remote core pointer used for sending mbox msg > >> + * > >> + * This function sends the shutdown prepare message to remote processor > >> and > >> + * waits for an ACK. Further, it checks if the remote processor has > >> entered > >> + * into WFI mode. It is invoked in shutdown sequence to ensure the rproc > >> + * has relinquished its resources before asserting a reset, so the > >> shutdown > >> + * happens cleanly. > >> + */ > >> +int notify_shutdown_rproc(struct k3_rproc *kproc) > >> +{ > >> + bool wfi_status = false; > >> + int ret; > >> + > >> + reinit_completion(&kproc->shutdown_complete); > >> + > >> + ret = mbox_send_message(kproc->mbox, (void > >> *)(uintptr_t)RP_MBOX_SHUTDOWN); > >> + if (ret < 0) { > >> + dev_err(kproc->dev, "PM mbox_send_message failed: %d\n", > >> ret); > >> + return ret; > >> + } > >> + > >> + ret = wait_for_completion_timeout(&kproc->shutdown_complete, > >> + msecs_to_jiffies(5000)); > >> + if (ret == 0) { > >> + dev_err(kproc->dev, "%s: timeout waiting for rproc > >> completion event\n", > >> + __func__); > >> + return -EBUSY; > >> + } > >> + > >> + ret = readx_poll_timeout(is_core_in_wfi, kproc, wfi_status, > >> wfi_status, > >> + 200, 2000); > >> + if (ret) > >> + return ret; > >> + > >> + return 0; > >> +} > >> +EXPORT_SYMBOL_GPL(notify_shutdown_rproc); > >> + > >> /* > >> * The K3 DSP and M4 cores have a local reset that affects only the CPU, > >> and a > >> * generic module reset that powers on the device and allows the internal > >> @@ -288,6 +355,11 @@ EXPORT_SYMBOL_GPL(k3_rproc_start); > >> int k3_rproc_stop(struct rproc *rproc) > >> { > >> struct k3_rproc *kproc = rproc->priv; > >> + int ret; > >> + > >> + ret = notify_shutdown_rproc(kproc); > >> + if (ret) > >> + return ret; > >> > >> return k3_rproc_reset(kproc); > >> } > >> diff --git a/drivers/remoteproc/ti_k3_common.h > >> b/drivers/remoteproc/ti_k3_common.h > >> index aee3c28dbe510..2a025f4894b82 100644 > >> --- a/drivers/remoteproc/ti_k3_common.h > >> +++ b/drivers/remoteproc/ti_k3_common.h > >> @@ -22,6 +22,7 @@ > >> #define REMOTEPROC_TI_K3_COMMON_H > >> > >> #define KEYSTONE_RPROC_LOCAL_ADDRESS_MASK (SZ_16M - 1) > >> +#define PROC_BOOT_STATUS_FLAG_CPU_WFI 0x00000002 > >> > >> /** > >> * struct k3_rproc_mem - internal memory structure > >> @@ -92,6 +93,7 @@ struct k3_rproc { > >> u32 ti_sci_id; > >> struct mbox_chan *mbox; > >> struct mbox_client client; > >> + struct completion shutdown_complete; > >> void *priv; > >> }; > >> > >> @@ -115,4 +117,6 @@ int k3_rproc_of_get_memories(struct platform_device > >> *pdev, > >> void k3_mem_release(void *data); > >> int k3_reserved_mem_init(struct k3_rproc *kproc); > >> void k3_release_tsp(void *data); > >> +bool is_core_in_wfi(struct k3_rproc *kproc); > >> +int notify_shutdown_rproc(struct k3_rproc *kproc); > >> #endif /* REMOTEPROC_TI_K3_COMMON_H */ > >> diff --git a/drivers/remoteproc/ti_k3_dsp_remoteproc.c > >> b/drivers/remoteproc/ti_k3_dsp_remoteproc.c > >> index d6ceea6dc920e..156ae09d8ee25 100644 > >> --- a/drivers/remoteproc/ti_k3_dsp_remoteproc.c > >> +++ b/drivers/remoteproc/ti_k3_dsp_remoteproc.c > >> @@ -133,6 +133,8 @@ static int k3_dsp_rproc_probe(struct platform_device > >> *pdev) > >> if (ret) > >> return ret; > >> > >> + init_completion(&kproc->shutdown_complete); > >> + > >> ret = k3_rproc_of_get_memories(pdev, kproc); > >> if (ret) > >> return ret; > >> diff --git a/drivers/remoteproc/ti_k3_m4_remoteproc.c > >> b/drivers/remoteproc/ti_k3_m4_remoteproc.c > >> index 3a11fd24eb52b..64d99071279b0 100644 > >> --- a/drivers/remoteproc/ti_k3_m4_remoteproc.c > >> +++ b/drivers/remoteproc/ti_k3_m4_remoteproc.c > >> @@ -90,6 +90,8 @@ static int k3_m4_rproc_probe(struct platform_device > >> *pdev) > >> if (ret) > >> return ret; > >> > >> + init_completion(&kproc->shutdown_complete); > >> + > >> ret = k3_rproc_of_get_memories(pdev, kproc); > >> if (ret) > >> return ret; > >> diff --git a/drivers/remoteproc/ti_k3_r5_remoteproc.c > >> b/drivers/remoteproc/ti_k3_r5_remoteproc.c > >> index 04f23295ffc10..8748dc6089cc2 100644 > >> --- a/drivers/remoteproc/ti_k3_r5_remoteproc.c > >> +++ b/drivers/remoteproc/ti_k3_r5_remoteproc.c > >> @@ -533,6 +533,10 @@ static int k3_r5_rproc_stop(struct rproc *rproc) > >> struct k3_r5_cluster *cluster = core->cluster; > >> int ret; > >> > >> + ret = notify_shutdown_rproc(kproc); > >> + if (ret) > >> + return ret; > >> + > >> /* halt all applicable cores */ > >> if (cluster->mode == CLUSTER_MODE_LOCKSTEP) { > >> list_for_each_entry(core, &cluster->cores, elem) { > >> @@ -1129,6 +1133,7 @@ static int k3_r5_cluster_rproc_init(struct > >> platform_device *pdev) > >> goto out; > >> } > >> > >> + init_completion(&kproc->shutdown_complete); > >> init_rmem: > >> k3_r5_adjust_tcm_sizes(kproc); > >> > >> -- > >> 2.34.1 > >> > >>
