From: Mathieu Poirier <mathieu.poirier@linaro.org>
To: ohad@wizery.com, bjorn.andersson@linaro.org
Cc: arnaud.pouliquen@st.com, mcoquelin.stm32@gmail.com,
alexandre.torgue@st.com, linux-remoteproc@vger.kernel.org,
linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org
Subject: [PATCH v7 10/17] remoteproc: Introduce function rproc_detach()
Date: Wed, 10 Mar 2021 14:10:18 -0700 [thread overview]
Message-ID: <20210310211025.1084636-11-mathieu.poirier@linaro.org> (raw)
In-Reply-To: <20210310211025.1084636-1-mathieu.poirier@linaro.org>
Introduce function rproc_detach() to enable the remoteproc
core to release the resources associated with a remote processor
without stopping its operation.
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Arnaud Pouliquen <arnaud.pouliquen@st.com>
---
drivers/remoteproc/remoteproc_core.c | 58 +++++++++++++++++++++++++++-
include/linux/remoteproc.h | 1 +
2 files changed, 58 insertions(+), 1 deletion(-)
diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
index f2a005eadfd5..5eaa47c3ba92 100644
--- a/drivers/remoteproc/remoteproc_core.c
+++ b/drivers/remoteproc/remoteproc_core.c
@@ -1709,7 +1709,7 @@ static int rproc_stop(struct rproc *rproc, bool crashed)
/*
* __rproc_detach(): Does the opposite of __rproc_attach()
*/
-static int __maybe_unused __rproc_detach(struct rproc *rproc)
+static int __rproc_detach(struct rproc *rproc)
{
struct device *dev = &rproc->dev;
int ret;
@@ -1948,6 +1948,62 @@ void rproc_shutdown(struct rproc *rproc)
}
EXPORT_SYMBOL(rproc_shutdown);
+/**
+ * rproc_detach() - Detach the remote processor from the
+ * remoteproc core
+ *
+ * @rproc: the remote processor
+ *
+ * Detach a remote processor (previously attached to with rproc_attach()).
+ *
+ * In case @rproc is still being used by an additional user(s), then
+ * this function will just decrement the power refcount and exit,
+ * without disconnecting the device.
+ *
+ * Function rproc_detach() calls __rproc_detach() in order to let a remote
+ * processor know that services provided by the application processor are
+ * no longer available. From there it should be possible to remove the
+ * platform driver and even power cycle the application processor (if the HW
+ * supports it) without needing to switch off the remote processor.
+ */
+int rproc_detach(struct rproc *rproc)
+{
+ struct device *dev = &rproc->dev;
+ int ret;
+
+ ret = mutex_lock_interruptible(&rproc->lock);
+ if (ret) {
+ dev_err(dev, "can't lock rproc %s: %d\n", rproc->name, ret);
+ return ret;
+ }
+
+ /* if the remote proc is still needed, bail out */
+ if (!atomic_dec_and_test(&rproc->power)) {
+ ret = 0;
+ goto out;
+ }
+
+ ret = __rproc_detach(rproc);
+ if (ret) {
+ atomic_inc(&rproc->power);
+ goto out;
+ }
+
+ /* clean up all acquired resources */
+ rproc_resource_cleanup(rproc);
+
+ /* release HW resources if needed */
+ rproc_unprepare_device(rproc);
+
+ rproc_disable_iommu(rproc);
+
+ rproc->table_ptr = NULL;
+out:
+ mutex_unlock(&rproc->lock);
+ return ret;
+}
+EXPORT_SYMBOL(rproc_detach);
+
/**
* rproc_get_by_phandle() - find a remote processor by phandle
* @phandle: phandle to the rproc
diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h
index eff55ec72e80..e1c843c19cc6 100644
--- a/include/linux/remoteproc.h
+++ b/include/linux/remoteproc.h
@@ -662,6 +662,7 @@ rproc_of_resm_mem_entry_init(struct device *dev, u32 of_resm_idx, size_t len,
int rproc_boot(struct rproc *rproc);
void rproc_shutdown(struct rproc *rproc);
+int rproc_detach(struct rproc *rproc);
int rproc_set_firmware(struct rproc *rproc, const char *fw_name);
void rproc_report_crash(struct rproc *rproc, enum rproc_crash_type type);
void rproc_coredump_using_sections(struct rproc *rproc);
--
2.25.1
next prev parent reply other threads:[~2021-03-10 21:11 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-10 21:10 [PATCH v7 00/17] remoteproc: Add support for detaching a remote processor Mathieu Poirier
2021-03-10 21:10 ` [PATCH v7 01/17] remoteproc: Remove useless check in rproc_del() Mathieu Poirier
2021-03-10 21:10 ` [PATCH v7 02/17] remoteproc: Rename function rproc_actuate() Mathieu Poirier
2021-03-10 21:10 ` [PATCH v7 03/17] remoteproc: Add new RPROC_ATTACHED state Mathieu Poirier
2021-03-10 21:10 ` [PATCH v7 04/17] remoteproc: Properly represent the attached state Mathieu Poirier
2021-03-10 21:10 ` [PATCH v7 05/17] remoteproc: Add new get_loaded_rsc_table() to rproc_ops Mathieu Poirier
2021-03-10 21:10 ` [PATCH v7 06/17] remoteproc: stm32: Move resource table setup " Mathieu Poirier
2021-03-10 21:10 ` [PATCH v7 07/17] remoteproc: stm32: Move memory parsing " Mathieu Poirier
2021-03-10 21:10 ` [PATCH v7 08/17] remoteproc: Add new detach() remoteproc operation Mathieu Poirier
2021-03-10 21:10 ` [PATCH v7 09/17] remoteproc: Introduce function __rproc_detach() Mathieu Poirier
2021-03-10 21:10 ` Mathieu Poirier [this message]
2021-03-10 21:10 ` [PATCH v7 11/17] remoteproc: Properly deal with the resource table when detaching Mathieu Poirier
2021-03-11 9:09 ` Arnaud POULIQUEN
2021-03-10 21:10 ` [PATCH v7 12/17] remoteproc: Properly deal with the resource table when stopping Mathieu Poirier
2021-03-10 23:00 ` kernel test robot
2021-03-10 23:53 ` Bjorn Andersson
2021-03-11 9:14 ` Arnaud POULIQUEN
2021-03-11 17:13 ` Mathieu Poirier
2021-03-10 21:10 ` [PATCH v7 13/17] remoteproc: Properly deal with a kernel panic when attached Mathieu Poirier
2021-03-10 21:10 ` [PATCH v7 14/17] remoteproc: Properly deal with a start request " Mathieu Poirier
2021-03-10 21:10 ` [PATCH v7 15/17] remoteproc: Properly deal with a stop " Mathieu Poirier
2021-03-10 21:10 ` [PATCH v7 16/17] remoteproc: Properly deal with a detach " Mathieu Poirier
2021-03-10 21:10 ` [PATCH v7 17/17] remoteproc: Refactor function rproc_cdev_release() Mathieu Poirier
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