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: [RFC PATCH 03/10] firmware: arm_scmi: Add configurable polling mode for transports Date: Sun, 6 Jun 2021 23:12:25 +0100 [thread overview] Message-ID: <20210606221232.33768-4-cristian.marussi@arm.com> (raw) In-Reply-To: <20210606221232.33768-1-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 evaluates the transport-specific .poll_done() function to determine if a request was 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.needs_polling: 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> --- drivers/firmware/arm_scmi/common.h | 10 ++++++++++ drivers/firmware/arm_scmi/driver.c | 17 +++++++++++++++++ 2 files changed, 27 insertions(+) diff --git a/drivers/firmware/arm_scmi/common.h b/drivers/firmware/arm_scmi/common.h index 8685619d38f9..8f4e6ebfc0ef 100644 --- a/drivers/firmware/arm_scmi/common.h +++ b/drivers/firmware/arm_scmi/common.h @@ -272,11 +272,18 @@ 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 + * @needs_polling: Flag to indicate that this channel has no completion + * interrupt mechanism, so it needs SCMI core to poll, using + * .poll_done(), to determine when a command has completed. + * This can be dynamically set by transports at run-time inside + * their provided .chan_setup() when they determine no + * completion interrupt is available. * @transport_info: Transport layer related information */ struct scmi_chan_info { struct device *dev; struct scmi_handle *handle; + bool needs_polling; void *transport_info; }; @@ -322,12 +329,15 @@ struct scmi_device *scmi_child_dev_find(struct device *parent, * @max_msg: Maximum number of messages that can be pending * simultaneously in the system * @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 { const struct scmi_transport_ops *ops; int max_rx_timeout_ms; int max_msg; int max_msg_size; + bool force_polling; }; extern const struct scmi_desc scmi_mailbox_desc; diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c index 759ae4a23e74..c11ff49f6b62 100644 --- a/drivers/firmware/arm_scmi/driver.c +++ b/drivers/firmware/arm_scmi/driver.c @@ -319,6 +319,15 @@ static void scmi_handle_response(struct scmi_chan_info *cinfo, } xfer = &minfo->xfer_block[xfer_id]; + + /* Discard unexpected messages when polling is active. */ + if (msg_type != MSG_TYPE_DELAYED_RESP && xfer->hdr.poll_completion) { + WARN_ON_ONCE(1); + dev_dbg(dev, + "Completion IRQ received but using polling. Ignore.\n"); + return; + } + /* * Even if a response was indeed expected on this slot at this point, * a buggy platform could wrongly reply feeding us an unexpected @@ -443,6 +452,9 @@ static int do_xfer(const struct scmi_protocol_handle *ph, if (unlikely(!cinfo)) return -EINVAL; + if (info->desc->force_polling || cinfo->needs_polling) + xfer->hdr.poll_completion = true; + trace_scmi_xfer_begin(xfer->transfer_id, xfer->hdr.id, xfer->hdr.protocol_id, xfer->hdr.seq, xfer->hdr.poll_completion); @@ -1102,6 +1114,11 @@ static int scmi_chan_setup(struct scmi_info *info, struct device *dev, if (ret) return ret; + if (tx && (cinfo->needs_polling || info->desc->force_polling)) + dev_info(dev, + "Enabled polling mode for TX channel - prot_id:%d\n", + prot_id); + 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: [RFC PATCH 03/10] firmware: arm_scmi: Add configurable polling mode for transports Date: Sun, 6 Jun 2021 23:12:25 +0100 [thread overview] Message-ID: <20210606221232.33768-4-cristian.marussi@arm.com> (raw) In-Reply-To: <20210606221232.33768-1-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 evaluates the transport-specific .poll_done() function to determine if a request was 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.needs_polling: 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> --- drivers/firmware/arm_scmi/common.h | 10 ++++++++++ drivers/firmware/arm_scmi/driver.c | 17 +++++++++++++++++ 2 files changed, 27 insertions(+) diff --git a/drivers/firmware/arm_scmi/common.h b/drivers/firmware/arm_scmi/common.h index 8685619d38f9..8f4e6ebfc0ef 100644 --- a/drivers/firmware/arm_scmi/common.h +++ b/drivers/firmware/arm_scmi/common.h @@ -272,11 +272,18 @@ 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 + * @needs_polling: Flag to indicate that this channel has no completion + * interrupt mechanism, so it needs SCMI core to poll, using + * .poll_done(), to determine when a command has completed. + * This can be dynamically set by transports at run-time inside + * their provided .chan_setup() when they determine no + * completion interrupt is available. * @transport_info: Transport layer related information */ struct scmi_chan_info { struct device *dev; struct scmi_handle *handle; + bool needs_polling; void *transport_info; }; @@ -322,12 +329,15 @@ struct scmi_device *scmi_child_dev_find(struct device *parent, * @max_msg: Maximum number of messages that can be pending * simultaneously in the system * @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 { const struct scmi_transport_ops *ops; int max_rx_timeout_ms; int max_msg; int max_msg_size; + bool force_polling; }; extern const struct scmi_desc scmi_mailbox_desc; diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c index 759ae4a23e74..c11ff49f6b62 100644 --- a/drivers/firmware/arm_scmi/driver.c +++ b/drivers/firmware/arm_scmi/driver.c @@ -319,6 +319,15 @@ static void scmi_handle_response(struct scmi_chan_info *cinfo, } xfer = &minfo->xfer_block[xfer_id]; + + /* Discard unexpected messages when polling is active. */ + if (msg_type != MSG_TYPE_DELAYED_RESP && xfer->hdr.poll_completion) { + WARN_ON_ONCE(1); + dev_dbg(dev, + "Completion IRQ received but using polling. Ignore.\n"); + return; + } + /* * Even if a response was indeed expected on this slot at this point, * a buggy platform could wrongly reply feeding us an unexpected @@ -443,6 +452,9 @@ static int do_xfer(const struct scmi_protocol_handle *ph, if (unlikely(!cinfo)) return -EINVAL; + if (info->desc->force_polling || cinfo->needs_polling) + xfer->hdr.poll_completion = true; + trace_scmi_xfer_begin(xfer->transfer_id, xfer->hdr.id, xfer->hdr.protocol_id, xfer->hdr.seq, xfer->hdr.poll_completion); @@ -1102,6 +1114,11 @@ static int scmi_chan_setup(struct scmi_info *info, struct device *dev, if (ret) return ret; + if (tx && (cinfo->needs_polling || info->desc->force_polling)) + dev_info(dev, + "Enabled polling mode for TX channel - prot_id:%d\n", + prot_id); + 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:[~2021-06-06 22:13 UTC|newest] Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-06-06 22:12 [RFC PATCH 00/10] Introduce SCMI transport atomic support Cristian Marussi 2021-06-06 22:12 ` Cristian Marussi 2021-06-06 22:12 ` [RFC PATCH 01/10] firmware: arm_scmi: Reset properly xfer SCMI status Cristian Marussi 2021-06-06 22:12 ` Cristian Marussi 2021-06-07 17:38 ` Sudeep Holla 2021-06-07 17:38 ` Sudeep Holla 2021-06-07 18:01 ` Cristian Marussi 2021-06-07 18:01 ` Cristian Marussi 2021-06-07 18:27 ` Sudeep Holla 2021-06-07 18:27 ` Sudeep Holla 2021-06-08 10:10 ` Cristian Marussi 2021-06-08 10:10 ` Cristian Marussi 2021-06-08 11:17 ` Sudeep Holla 2021-06-08 11:17 ` Sudeep Holla 2021-06-06 22:12 ` [RFC PATCH 02/10] firmware: arm_scmi: Add missing xfer reinit_completion Cristian Marussi 2021-06-06 22:12 ` Cristian Marussi 2021-06-07 17:42 ` Sudeep Holla 2021-06-07 17:42 ` Sudeep Holla 2021-06-07 18:04 ` Cristian Marussi 2021-06-07 18:04 ` Cristian Marussi 2021-06-07 18:30 ` Sudeep Holla 2021-06-07 18:30 ` Sudeep Holla 2021-06-09 20:51 ` Sudeep Holla 2021-06-09 20:51 ` Sudeep Holla 2021-06-06 22:12 ` Cristian Marussi [this message] 2021-06-06 22:12 ` [RFC PATCH 03/10] firmware: arm_scmi: Add configurable polling mode for transports Cristian Marussi 2021-06-06 22:12 ` [RFC PATCH 04/10] firmware: arm_scmi: Add support for atomic transports Cristian Marussi 2021-06-06 22:12 ` Cristian Marussi 2021-06-06 22:12 ` [RFC PATCH 05/10] include: trace: Add new scmi_xfer_response_wait event Cristian Marussi 2021-06-06 22:12 ` Cristian Marussi 2021-06-06 22:12 ` [RFC PATCH 06/10] firmware: arm_scmi: Use new trace event scmi_xfer_response_wait Cristian Marussi 2021-06-06 22:12 ` Cristian Marussi 2021-06-06 22:12 ` [RFC PATCH 07/10] firmware: arm_scmi: Add is_transport_atomic() handle method Cristian Marussi 2021-06-06 22:12 ` Cristian Marussi 2021-06-06 22:12 ` [RFC PATCH 08/10] clk: scmi: Support atomic enable/disable API Cristian Marussi 2021-06-06 22:12 ` Cristian Marussi 2021-06-06 22:12 ` [RFC PATCH 09/10] firmware: arm-scmi: Make smc transport use common completions Cristian Marussi 2021-06-06 22:12 ` Cristian Marussi 2021-06-06 22:12 ` [RFC PATCH 10/10] firmware: arm-scmi: Make smc transport atomic Cristian Marussi 2021-06-06 22:12 ` Cristian Marussi
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