Message ID | 1617943188-23278-2-git-send-email-deesin@qti.qualcomm.com (mailing list archive) |
---|---|
State | Superseded |
Headers | show |
Series | soc: qcom: aoss: Expose send for generic usecase | expand |
On Thu 08 Apr 23:39 CDT 2021, Deepak Kumar Singh wrote: [..] > +/** > + * qmp_get() - get a qmp handle from a device > + * @dev: client device pointer > + * > + * Return: handle to qmp device on success, ERR_PTR() on failure > + */ > +struct qmp *qmp_get(struct device *dev) > +{ > + struct platform_device *pdev; > + struct device_node *np; > + struct qmp *qmp; > + > + if (!dev || !dev->of_node) > + return ERR_PTR(-EINVAL); > + > + np = of_parse_phandle(dev->of_node, "qcom,qmp", 0); > + if (!np) > + return ERR_PTR(-ENODEV); > + > + pdev = of_find_device_by_node(np); > + if (!pdev) > + return ERR_PTR(-EINVAL); > + > + qmp = platform_get_drvdata(pdev); > + return qmp ? qmp : ERR_PTR(-EPROBE_DEFER); > +} > +EXPORT_SYMBOL(qmp_get); > + > +void qmp_put(struct platform_device *pdev) > +{ > + platform_device_put(pdev); I was expecting that the devres allocated struct qmp would stick around until the struct device's release callback came. As described in my answer to Mani yesterday I was wrong. As such you need to make sure that struct qmp stays around until qmp_remove() and all qmp_put() calls has been made. I presume a reasonable way to achieve this is to not use devm to allocate our struct qmp, add a kref to the object. So this would have to be a kref_put() on that instead of the platform_device_put() I asked you to implement here. Sorry about that. The rest of the patch looks good. Regards, Bjorn
On 4/14/2021 2:42 AM, Bjorn Andersson wrote: > On Thu 08 Apr 23:39 CDT 2021, Deepak Kumar Singh wrote: > [..] >> +/** >> + * qmp_get() - get a qmp handle from a device >> + * @dev: client device pointer >> + * >> + * Return: handle to qmp device on success, ERR_PTR() on failure >> + */ >> +struct qmp *qmp_get(struct device *dev) >> +{ >> + struct platform_device *pdev; >> + struct device_node *np; >> + struct qmp *qmp; >> + >> + if (!dev || !dev->of_node) >> + return ERR_PTR(-EINVAL); >> + >> + np = of_parse_phandle(dev->of_node, "qcom,qmp", 0); >> + if (!np) >> + return ERR_PTR(-ENODEV); >> + >> + pdev = of_find_device_by_node(np); >> + if (!pdev) >> + return ERR_PTR(-EINVAL); >> + >> + qmp = platform_get_drvdata(pdev); >> + return qmp ? qmp : ERR_PTR(-EPROBE_DEFER); >> +} >> +EXPORT_SYMBOL(qmp_get); >> + >> +void qmp_put(struct platform_device *pdev) >> +{ >> + platform_device_put(pdev); > I was expecting that the devres allocated struct qmp would stick around > until the struct device's release callback came. As described in my > answer to Mani yesterday I was wrong. > > As such you need to make sure that struct qmp stays around until > qmp_remove() and all qmp_put() calls has been made. > > I presume a reasonable way to achieve this is to not use devm to > allocate our struct qmp, add a kref to the object. So this would have to > be a kref_put() on that instead of the platform_device_put() I asked you > to implement here. > > Sorry about that. > > > The rest of the patch looks good. > > Regards, > Bjorn Hi Bjorn, Even if we use kref_put(), would it not require platform_device_put()? As per my understanding of_find_device_by_node(np) will increment node/pdev kobj refcount which both needs to be decremented.
diff --git a/drivers/soc/qcom/qcom_aoss.c b/drivers/soc/qcom/qcom_aoss.c index 53acb94..0e397a7 100644 --- a/drivers/soc/qcom/qcom_aoss.c +++ b/drivers/soc/qcom/qcom_aoss.c @@ -8,10 +8,12 @@ #include <linux/io.h> #include <linux/mailbox_client.h> #include <linux/module.h> +#include <linux/of_platform.h> #include <linux/platform_device.h> #include <linux/pm_domain.h> #include <linux/thermal.h> #include <linux/slab.h> +#include <linux/soc/qcom/qcom_aoss.h> #define QMP_DESC_MAGIC 0x0 #define QMP_DESC_VERSION 0x4 @@ -61,6 +63,7 @@ struct qmp_cooling_device { * @mbox_chan: mailbox channel used to ring the doorbell on transmit * @offset: offset within @msgram where messages should be written * @size: maximum size of the messages to be transmitted + * @orphan: tarcks whether qmp handle is valid * @event: wait_queue for synchronization with the IRQ * @tx_lock: provides synchronization between multiple callers of qmp_send() * @qdss_clk: QDSS clock hw struct @@ -76,6 +79,7 @@ struct qmp { size_t offset; size_t size; + atomic_t orphan; wait_queue_head_t event; @@ -223,11 +227,17 @@ static bool qmp_message_empty(struct qmp *qmp) * * Return: 0 on success, negative errno on failure */ -static int qmp_send(struct qmp *qmp, const void *data, size_t len) +int qmp_send(struct qmp *qmp, const void *data, size_t len) { long time_left; int ret; + if (WARN_ON(IS_ERR_OR_NULL(qmp) || !data)) + return -EINVAL; + + if (atomic_read(&qmp->orphan)) + return -EINVAL; + if (WARN_ON(len + sizeof(u32) > qmp->size)) return -EINVAL; @@ -261,6 +271,7 @@ static int qmp_send(struct qmp *qmp, const void *data, size_t len) return ret; } +EXPORT_SYMBOL(qmp_send); static int qmp_qdss_clk_prepare(struct clk_hw *hw) { @@ -515,6 +526,40 @@ static void qmp_cooling_devices_remove(struct qmp *qmp) thermal_cooling_device_unregister(qmp->cooling_devs[i].cdev); } +/** + * qmp_get() - get a qmp handle from a device + * @dev: client device pointer + * + * Return: handle to qmp device on success, ERR_PTR() on failure + */ +struct qmp *qmp_get(struct device *dev) +{ + struct platform_device *pdev; + struct device_node *np; + struct qmp *qmp; + + if (!dev || !dev->of_node) + return ERR_PTR(-EINVAL); + + np = of_parse_phandle(dev->of_node, "qcom,qmp", 0); + if (!np) + return ERR_PTR(-ENODEV); + + pdev = of_find_device_by_node(np); + if (!pdev) + return ERR_PTR(-EINVAL); + + qmp = platform_get_drvdata(pdev); + return qmp ? qmp : ERR_PTR(-EPROBE_DEFER); +} +EXPORT_SYMBOL(qmp_get); + +void qmp_put(struct platform_device *pdev) +{ + platform_device_put(pdev); +} +EXPORT_SYMBOL(qmp_put); + static int qmp_probe(struct platform_device *pdev) { struct resource *res; @@ -569,6 +614,8 @@ static int qmp_probe(struct platform_device *pdev) platform_set_drvdata(pdev, qmp); + atomic_set(&qmp->orphan, 0); + return 0; err_remove_qdss_clk: @@ -590,6 +637,7 @@ static int qmp_remove(struct platform_device *pdev) qmp_cooling_devices_remove(qmp); qmp_close(qmp); + atomic_set(&qmp->orphan, 1); mbox_free_channel(qmp->mbox_chan); return 0; diff --git a/include/linux/soc/qcom/qcom_aoss.h b/include/linux/soc/qcom/qcom_aoss.h new file mode 100644 index 0000000..27d00f7 --- /dev/null +++ b/include/linux/soc/qcom/qcom_aoss.h @@ -0,0 +1,33 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (c) 2020, The Linux Foundation. All rights reserved. + */ + +#ifndef __QCOM_AOSS_H__ +#define __QCOM_AOSS_H__ + +#include <linux/err.h> +#include <linux/device.h> + +struct qmp; + +#if IS_ENABLED(CONFIG_QCOM_AOSS_QMP) + +int qmp_send(struct qmp *qmp, const void *data, size_t len); +struct qmp *qmp_get(struct device *dev); + +#else + +static inline int qmp_send(struct qmp *qmp, const void *data, size_t len) +{ + return -ENODEV; +} + +static inline struct qmp *qmp_get(struct device *dev) +{ + return ERR_PTR(-ENODEV); +} + +#endif + +#endif