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 (maybe it has crashed). Is there a way to cleanup resources which the remote core allocated without rebooting the whole system? 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 > >
