From: Cristian Marussi <cristian.marussi@arm.com> To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Cc: sudeep.holla@arm.com, james.quinlan@broadcom.com, Jonathan.Cameron@Huawei.com, f.fainelli@gmail.com, etienne.carriere@linaro.org, vincent.guittot@linaro.org, souvik.chakravarty@arm.com, cristian.marussi@arm.com Subject: [PATCH v8 01/11] firmware: arm_scmi: Add configurable polling mode for transports Date: Mon, 20 Dec 2021 19:56:36 +0000 [thread overview] Message-ID: <20211220195646.44498-2-cristian.marussi@arm.com> (raw) In-Reply-To: <20211220195646.44498-1-cristian.marussi@arm.com> SCMI communications along TX channels can optionally be provided of a completion interrupt; when such interrupt is not available, command transactions should rely on polling, where the SCMI core takes care to repeatedly evaluate the transport-specific .poll_done() function, if available, to determine if and when a request was fully completed or timed out. Such mechanism is already present and working on a single transfer base: SCMI protocols can indeed enable hdr.poll_completion on specific commands ahead of each transfer and cause that transaction to be handled with polling. Introduce a couple of flags to be able to enforce such polling behaviour globally at will: - scmi_desc.force_polling: to statically switch the whole transport to polling mode. - scmi_chan_info.no_completion_irq: to switch a single channel dynamically to polling mode if, at runtime, is determined that no completion interrupt was available for such channel. Signed-off-by: Cristian Marussi <cristian.marussi@arm.com> --- v7 --> v8 - removed internal poling_enabled flag, using macros v5 --> v6 - removed check on replies received by IRQs when xfer was requested as poll_completion (not all transport can suppress IRQs on an xfer basis) v4 --> v5 - make force_polling const - introduce polling_enabled flag to simplify checks on do_xfer v3 --> v4: - renamed .needs_polling flag to .no_completion_irq - refactored error path when polling needed but not supported --- drivers/firmware/arm_scmi/common.h | 8 ++++++++ drivers/firmware/arm_scmi/driver.c | 32 ++++++++++++++++++++++++++++++ 2 files changed, 40 insertions(+) diff --git a/drivers/firmware/arm_scmi/common.h b/drivers/firmware/arm_scmi/common.h index 6438b5248c24..652e5d95ee65 100644 --- a/drivers/firmware/arm_scmi/common.h +++ b/drivers/firmware/arm_scmi/common.h @@ -339,11 +339,16 @@ void scmi_protocol_release(const struct scmi_handle *handle, u8 protocol_id); * @dev: Reference to device in the SCMI hierarchy corresponding to this * channel * @handle: Pointer to SCMI entity handle + * @no_completion_irq: Flag to indicate that this channel has no completion + * interrupt mechanism for synchronous commands. + * This can be dynamically set by transports at run-time + * inside their provided .chan_setup(). * @transport_info: Transport layer related information */ struct scmi_chan_info { struct device *dev; struct scmi_handle *handle; + bool no_completion_irq; void *transport_info; }; @@ -402,6 +407,8 @@ struct scmi_device *scmi_child_dev_find(struct device *parent, * be pending simultaneously in the system. May be overridden by the * get_max_msg op. * @max_msg_size: Maximum size of data per message that can be handled. + * @force_polling: Flag to force this whole transport to use SCMI core polling + * mechanism instead of completion interrupts even if available. */ struct scmi_desc { int (*transport_init)(void); @@ -410,6 +417,7 @@ struct scmi_desc { int max_rx_timeout_ms; int max_msg; int max_msg_size; + const bool force_polling; }; #ifdef CONFIG_ARM_SCMI_TRANSPORT_MAILBOX diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c index 476b91845e40..cb9fc12503f2 100644 --- a/drivers/firmware/arm_scmi/driver.c +++ b/drivers/firmware/arm_scmi/driver.c @@ -36,6 +36,23 @@ #define CREATE_TRACE_POINTS #include <trace/events/scmi.h> +#define IS_POLLING_REQUIRED(__c, __i) \ + ((__c)->no_completion_irq || (__i)->desc->force_polling) \ + +#define IS_TRANSPORT_POLLING_CAPABLE(__i) \ + ((__i)->desc->ops->poll_done) + +#define IS_POLLING_ENABLED(__c, __i) \ +({ \ + bool __ret; \ + typeof(__c) c_ = __c; \ + typeof(__i) i_ = __i; \ + \ + __ret = (IS_POLLING_REQUIRED(c_, i_) && \ + IS_TRANSPORT_POLLING_CAPABLE(i_)); \ + __ret; \ +}) + enum scmi_error_codes { SCMI_SUCCESS = 0, /* Success */ SCMI_ERR_SUPPORT = -1, /* Not supported */ @@ -817,6 +834,7 @@ static int do_xfer(const struct scmi_protocol_handle *ph, struct device *dev = info->dev; struct scmi_chan_info *cinfo; + /* Check for polling request on custom command xfers at first */ if (xfer->hdr.poll_completion && !info->desc->ops->poll_done) { dev_warn_once(dev, "Polling mode is not supported by transport.\n"); @@ -827,6 +845,10 @@ static int do_xfer(const struct scmi_protocol_handle *ph, if (unlikely(!cinfo)) return -EINVAL; + /* True ONLY if also supported by transport. */ + if (IS_POLLING_ENABLED(cinfo, info)) + xfer->hdr.poll_completion = true; + /* * Initialise protocol id now from protocol handle to avoid it being * overridden by mistake (or malice) by the protocol code mangling with @@ -1527,6 +1549,16 @@ static int scmi_chan_setup(struct scmi_info *info, struct device *dev, if (ret) return ret; + if (tx && IS_POLLING_REQUIRED(cinfo, info)) { + if (IS_TRANSPORT_POLLING_CAPABLE(info)) + dev_info(dev, + "Enabled polling mode TX channel - prot_id:%d\n", + prot_id); + else + dev_warn(dev, + "Polling mode NOT supported by transport.\n"); + } + idr_alloc: ret = idr_alloc(idr, cinfo, prot_id, prot_id + 1, GFP_KERNEL); if (ret != prot_id) { -- 2.17.1
WARNING: multiple messages have this Message-ID (diff)
From: Cristian Marussi <cristian.marussi@arm.com> To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Cc: sudeep.holla@arm.com, james.quinlan@broadcom.com, Jonathan.Cameron@Huawei.com, f.fainelli@gmail.com, etienne.carriere@linaro.org, vincent.guittot@linaro.org, souvik.chakravarty@arm.com, cristian.marussi@arm.com Subject: [PATCH v8 01/11] firmware: arm_scmi: Add configurable polling mode for transports Date: Mon, 20 Dec 2021 19:56:36 +0000 [thread overview] Message-ID: <20211220195646.44498-2-cristian.marussi@arm.com> (raw) In-Reply-To: <20211220195646.44498-1-cristian.marussi@arm.com> SCMI communications along TX channels can optionally be provided of a completion interrupt; when such interrupt is not available, command transactions should rely on polling, where the SCMI core takes care to repeatedly evaluate the transport-specific .poll_done() function, if available, to determine if and when a request was fully completed or timed out. Such mechanism is already present and working on a single transfer base: SCMI protocols can indeed enable hdr.poll_completion on specific commands ahead of each transfer and cause that transaction to be handled with polling. Introduce a couple of flags to be able to enforce such polling behaviour globally at will: - scmi_desc.force_polling: to statically switch the whole transport to polling mode. - scmi_chan_info.no_completion_irq: to switch a single channel dynamically to polling mode if, at runtime, is determined that no completion interrupt was available for such channel. Signed-off-by: Cristian Marussi <cristian.marussi@arm.com> --- v7 --> v8 - removed internal poling_enabled flag, using macros v5 --> v6 - removed check on replies received by IRQs when xfer was requested as poll_completion (not all transport can suppress IRQs on an xfer basis) v4 --> v5 - make force_polling const - introduce polling_enabled flag to simplify checks on do_xfer v3 --> v4: - renamed .needs_polling flag to .no_completion_irq - refactored error path when polling needed but not supported --- drivers/firmware/arm_scmi/common.h | 8 ++++++++ drivers/firmware/arm_scmi/driver.c | 32 ++++++++++++++++++++++++++++++ 2 files changed, 40 insertions(+) diff --git a/drivers/firmware/arm_scmi/common.h b/drivers/firmware/arm_scmi/common.h index 6438b5248c24..652e5d95ee65 100644 --- a/drivers/firmware/arm_scmi/common.h +++ b/drivers/firmware/arm_scmi/common.h @@ -339,11 +339,16 @@ void scmi_protocol_release(const struct scmi_handle *handle, u8 protocol_id); * @dev: Reference to device in the SCMI hierarchy corresponding to this * channel * @handle: Pointer to SCMI entity handle + * @no_completion_irq: Flag to indicate that this channel has no completion + * interrupt mechanism for synchronous commands. + * This can be dynamically set by transports at run-time + * inside their provided .chan_setup(). * @transport_info: Transport layer related information */ struct scmi_chan_info { struct device *dev; struct scmi_handle *handle; + bool no_completion_irq; void *transport_info; }; @@ -402,6 +407,8 @@ struct scmi_device *scmi_child_dev_find(struct device *parent, * be pending simultaneously in the system. May be overridden by the * get_max_msg op. * @max_msg_size: Maximum size of data per message that can be handled. + * @force_polling: Flag to force this whole transport to use SCMI core polling + * mechanism instead of completion interrupts even if available. */ struct scmi_desc { int (*transport_init)(void); @@ -410,6 +417,7 @@ struct scmi_desc { int max_rx_timeout_ms; int max_msg; int max_msg_size; + const bool force_polling; }; #ifdef CONFIG_ARM_SCMI_TRANSPORT_MAILBOX diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c index 476b91845e40..cb9fc12503f2 100644 --- a/drivers/firmware/arm_scmi/driver.c +++ b/drivers/firmware/arm_scmi/driver.c @@ -36,6 +36,23 @@ #define CREATE_TRACE_POINTS #include <trace/events/scmi.h> +#define IS_POLLING_REQUIRED(__c, __i) \ + ((__c)->no_completion_irq || (__i)->desc->force_polling) \ + +#define IS_TRANSPORT_POLLING_CAPABLE(__i) \ + ((__i)->desc->ops->poll_done) + +#define IS_POLLING_ENABLED(__c, __i) \ +({ \ + bool __ret; \ + typeof(__c) c_ = __c; \ + typeof(__i) i_ = __i; \ + \ + __ret = (IS_POLLING_REQUIRED(c_, i_) && \ + IS_TRANSPORT_POLLING_CAPABLE(i_)); \ + __ret; \ +}) + enum scmi_error_codes { SCMI_SUCCESS = 0, /* Success */ SCMI_ERR_SUPPORT = -1, /* Not supported */ @@ -817,6 +834,7 @@ static int do_xfer(const struct scmi_protocol_handle *ph, struct device *dev = info->dev; struct scmi_chan_info *cinfo; + /* Check for polling request on custom command xfers at first */ if (xfer->hdr.poll_completion && !info->desc->ops->poll_done) { dev_warn_once(dev, "Polling mode is not supported by transport.\n"); @@ -827,6 +845,10 @@ static int do_xfer(const struct scmi_protocol_handle *ph, if (unlikely(!cinfo)) return -EINVAL; + /* True ONLY if also supported by transport. */ + if (IS_POLLING_ENABLED(cinfo, info)) + xfer->hdr.poll_completion = true; + /* * Initialise protocol id now from protocol handle to avoid it being * overridden by mistake (or malice) by the protocol code mangling with @@ -1527,6 +1549,16 @@ static int scmi_chan_setup(struct scmi_info *info, struct device *dev, if (ret) return ret; + if (tx && IS_POLLING_REQUIRED(cinfo, info)) { + if (IS_TRANSPORT_POLLING_CAPABLE(info)) + dev_info(dev, + "Enabled polling mode TX channel - prot_id:%d\n", + prot_id); + else + dev_warn(dev, + "Polling mode NOT supported by transport.\n"); + } + idr_alloc: ret = idr_alloc(idr, cinfo, prot_id, prot_id + 1, GFP_KERNEL); if (ret != prot_id) { -- 2.17.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2021-12-20 19:57 UTC|newest] Thread overview: 61+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-12-20 19:56 [PATCH v8 00/11] Introduce atomic support for SCMI transports Cristian Marussi 2021-12-20 19:56 ` Cristian Marussi 2021-12-20 19:56 ` Cristian Marussi [this message] 2021-12-20 19:56 ` [PATCH v8 01/11] firmware: arm_scmi: Add configurable polling mode for transports Cristian Marussi 2021-12-21 19:38 ` Pratyush Yadav 2021-12-21 19:38 ` Pratyush Yadav 2021-12-21 20:23 ` Sudeep Holla 2021-12-21 20:23 ` Sudeep Holla 2021-12-20 19:56 ` [PATCH v8 02/11] firmware: arm_scmi: Make smc transport use common completions Cristian Marussi 2021-12-20 19:56 ` Cristian Marussi 2021-12-20 19:56 ` [PATCH v8 03/11] firmware: arm_scmi: Add sync_cmds_completed_on_ret transport flag Cristian Marussi 2021-12-20 19:56 ` Cristian Marussi 2021-12-20 19:56 ` [PATCH v8 04/11] firmware: arm_scmi: Make smc support sync_cmds_completed_on_ret Cristian Marussi 2021-12-20 19:56 ` Cristian Marussi 2021-12-20 19:56 ` [PATCH v8 05/11] firmware: arm_scmi: Make optee " Cristian Marussi 2021-12-20 19:56 ` Cristian Marussi 2021-12-20 19:56 ` [PATCH v8 06/11] firmware: arm_scmi: Add support for atomic transports Cristian Marussi 2021-12-20 19:56 ` Cristian Marussi 2021-12-20 19:56 ` [PATCH v8 07/11] firmware: arm_scmi: Add atomic mode support to smc transport Cristian Marussi 2021-12-20 19:56 ` Cristian Marussi 2021-12-20 19:56 ` [PATCH v8 08/11] firmware: arm_scmi: Add new parameter to mark_txdone Cristian Marussi 2021-12-20 19:56 ` Cristian Marussi 2021-12-20 19:56 ` [PATCH v8 09/11] firmware: arm_scmi: Add atomic mode support to virtio transport Cristian Marussi 2021-12-20 19:56 ` Cristian Marussi 2021-12-20 23:17 ` Michael S. Tsirkin 2021-12-20 23:17 ` Michael S. Tsirkin 2021-12-20 23:17 ` Michael S. Tsirkin 2021-12-21 12:09 ` Cristian Marussi 2021-12-21 12:09 ` Cristian Marussi 2021-12-21 14:00 ` [PATCH v9 " Cristian Marussi 2021-12-21 14:00 ` Cristian Marussi 2022-01-18 14:21 ` Peter Hilber 2022-01-18 14:21 ` Peter Hilber 2022-01-19 12:23 ` Cristian Marussi 2022-01-19 12:23 ` Cristian Marussi 2022-01-20 19:09 ` Peter Hilber 2022-01-20 19:09 ` Peter Hilber 2022-01-20 20:39 ` Michael S. Tsirkin 2022-01-20 20:39 ` Michael S. Tsirkin 2022-01-20 20:39 ` Michael S. Tsirkin 2022-01-23 20:02 ` Cristian Marussi 2022-01-23 20:02 ` Cristian Marussi 2022-01-23 22:40 ` Michael S. Tsirkin 2022-01-23 22:40 ` Michael S. Tsirkin 2022-01-23 22:40 ` Michael S. Tsirkin 2022-01-23 22:45 ` Cristian Marussi 2022-01-23 22:45 ` Cristian Marussi 2021-12-20 19:56 ` [PATCH v8 10/11] firmware: arm_scmi: Add atomic support to clock protocol Cristian Marussi 2021-12-20 19:56 ` Cristian Marussi 2021-12-20 19:56 ` [PATCH v8 11/11] clk: scmi: Support atomic clock enable/disable API Cristian Marussi 2021-12-20 19:56 ` Cristian Marussi 2022-01-14 23:08 ` Stephen Boyd 2022-01-14 23:08 ` Stephen Boyd 2022-01-17 10:31 ` Sudeep Holla 2022-01-17 10:31 ` Sudeep Holla 2022-01-17 12:40 ` Cristian Marussi 2022-01-17 12:40 ` Cristian Marussi 2021-12-22 14:23 ` [PATCH v8 00/11] (subset) Introduce atomic support for SCMI transports Sudeep Holla 2021-12-22 14:23 ` Sudeep Holla 2022-01-11 18:13 ` [PATCH v8 00/11] " Cristian Marussi 2022-01-11 18:13 ` Cristian Marussi
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