| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <e917f964-85d9-4c33-a79a-d7f7474a6afb@ti.com>
Date: Thu, 27 Nov 2025 16:03:40 +0530
From: Beleswar Prasad Padhi <b-padhi@...com>
To: Patrick Oppenlander <patrick.oppenlander@...il.com>
CC: <andersson@...nel.org>, <mathieu.poirier@...aro.org>,
<richard.genoud@...tlin.com>, <afd@...com>, <hnagalla@...com>, <jm@...com>,
<u-kumar1@...com>, <jan.kiszka@...mens.com>, <christophe.jaillet@...adoo.fr>,
<linux-remoteproc@...r.kernel.org>, <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v2] remoteproc: k3: support for graceful shutdown of
remote cores
Hi Patrick, Mathieu,
On 27/11/25 02:11, Patrick Oppenlander wrote:
> On Tue, 25 Nov 2025 at 19:39, Beleswar Padhi <b-padhi@...com> wrote:
>> From: Richard Genoud <richard.genoud@...tlin.com>
>>
>> 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?
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 <hnagalla@...com>
>>
>> Signed-off-by: Richard Genoud <richard.genoud@...tlin.com>
>> [b-padhi@...com: Extend support to all rprocs]
>> Signed-off-by: Beleswar Padhi <b-padhi@...com>
>> ---
>> 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/20240621150058.319524-5-richard.genoud@bootlin.com/
>>
>> 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 <hnagalla@...com>
>> */
>>
>> +#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
>>
>>
Powered by blists - more mailing lists