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[68.147.0.187]) by smtp.gmail.com with ESMTPSA id iq6sm5932740pjb.6.2021.02.11.15.46.39 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 11 Feb 2021 15:46:40 -0800 (PST) From: Mathieu Poirier To: ohad@wizery.com, bjorn.andersson@linaro.org, arnaud.pouliquen@st.com Cc: robh+dt@kernel.org, mcoquelin.stm32@gmail.com, alexandre.torgue@st.com, linux-remoteproc@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: [PATCH v5 12/19] remoteproc: Introduce function rproc_detach() Date: Thu, 11 Feb 2021 16:46:20 -0700 Message-Id: <20210211234627.2669674-13-mathieu.poirier@linaro.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210211234627.2669674-1-mathieu.poirier@linaro.org> References: <20210211234627.2669674-1-mathieu.poirier@linaro.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-remoteproc@vger.kernel.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 --- New for V5: - Fixed comment about rproc_actuate() that no longer exists. - Added call to rproc_unprepare_device() to balance rproc_prepare_device() in function rproc_attach(). - Removed RB from Peng and Arnaud because of the above. --- drivers/remoteproc/remoteproc_core.c | 66 +++++++++++++++++++++++++++- include/linux/remoteproc.h | 1 + 2 files changed, 66 insertions(+), 1 deletion(-) diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c index b150138542d4..660dcc002ff6 100644 --- a/drivers/remoteproc/remoteproc_core.c +++ b/drivers/remoteproc/remoteproc_core.c @@ -1712,7 +1712,7 @@ 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; @@ -1954,6 +1954,70 @@ 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 (rproc->state != RPROC_RUNNING && rproc->state != RPROC_ATTACHED) { + ret = -EPERM; + goto out; + } + + /* if the remote proc is still needed, bail out */ + if (!atomic_dec_and_test(&rproc->power)) { + ret = -EBUSY; + 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); + + /* Follow the same sequence as in rproc_shutdown() */ + kfree(rproc->cached_table); + rproc->cached_table = NULL; + 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);