From 8ab5059dc4f4c34325eba6270ef12a4ab1386019 Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Mon, 23 Jan 2023 18:07:07 +0300 Subject: [PATCH 1/9] firmware: arm_scmi: Clean up a return statement in scmi_probe The comments say "enabled" where "disabled" is intended. Also it's cleaner to return zero explicitly instead of ret. Signed-off-by: Dan Carpenter Link: https://lore.kernel.org/r/Y86im5M49p3ePGxj@kili Signed-off-by: Sudeep Holla --- drivers/firmware/arm_scmi/driver.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c index d21c7eafd641..703f16ef3953 100644 --- a/drivers/firmware/arm_scmi/driver.c +++ b/drivers/firmware/arm_scmi/driver.c @@ -2739,8 +2739,8 @@ static int scmi_probe(struct platform_device *pdev) if (ret) goto clear_dev_req_notifier; - /* Bail out anyway when coex enabled */ - return ret; + /* Bail out anyway when coex disabled. */ + return 0; } /* Coex enabled, carry on in any case. */ From 6bed395d7db2c039c0ef4123a379e27c528a3357 Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Wed, 22 Feb 2023 18:17:06 +0300 Subject: [PATCH 2/9] firmware: arm_scmi: Return a literal instead of a variable In this context "return scmi_dev;" and "return NULL;" are equivalent but it is more readable to return a literal. Signed-off-by: Dan Carpenter Reviewed-by: Cristian Marussi Link: https://lore.kernel.org/r/Y/Yx8pOdf8rNhPVe@kili Signed-off-by: Sudeep Holla --- drivers/firmware/arm_scmi/bus.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/firmware/arm_scmi/bus.c b/drivers/firmware/arm_scmi/bus.c index 73140b854b31..ac306ca48b07 100644 --- a/drivers/firmware/arm_scmi/bus.c +++ b/drivers/firmware/arm_scmi/bus.c @@ -436,7 +436,7 @@ struct scmi_device *scmi_device_create(struct device_node *np, /* Nothing to do. */ if (!phead) { mutex_unlock(&scmi_requested_devices_mtx); - return scmi_dev; + return NULL; } /* Walk the list of requested devices for protocol and create them */ From 418a406d92cc276ddf81d4223271af1ae09fa5af Mon Sep 17 00:00:00 2001 From: Ye Xingchen Date: Fri, 10 Feb 2023 15:20:07 +0800 Subject: [PATCH 3/9] firmware: arm_scmi: Remove duplicate include header inclusion linux/of.h is included more than once, just remove the duplicate include header inclusion. Signed-off-by: Ye Xingchen Link: https://lore.kernel.org/r/202302101520071730986@zte.com.cn Signed-off-by: Sudeep Holla --- drivers/firmware/arm_scmi/bus.c | 1 - 1 file changed, 1 deletion(-) diff --git a/drivers/firmware/arm_scmi/bus.c b/drivers/firmware/arm_scmi/bus.c index ac306ca48b07..c15928b8c5cc 100644 --- a/drivers/firmware/arm_scmi/bus.c +++ b/drivers/firmware/arm_scmi/bus.c @@ -14,7 +14,6 @@ #include #include #include -#include #include "common.h" From b2b76e977fc6bc38e6a4dedb62b34bc90cc6ce97 Mon Sep 17 00:00:00 2001 From: Cristian Marussi Date: Thu, 23 Feb 2023 15:23:30 +0000 Subject: [PATCH 4/9] firmware: arm_scmi: Fix raw coexistence mode behaviour on failure path When SCMI raw coexistence mode is enabled make the core stack probe successfully even when the initial base protocol exchanges with the platform/server failed. This behaviour enables the system to boot with a broken regular SCMI stack but with a fully functional and accessible SCMI raw debugfs interface that can be used to further debug the issue. Signed-off-by: Cristian Marussi Link: https://lore.kernel.org/r/20230223152330.2707260-1-cristian.marussi@arm.com Signed-off-by: Sudeep Holla --- drivers/firmware/arm_scmi/driver.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c index 703f16ef3953..15a431639d82 100644 --- a/drivers/firmware/arm_scmi/driver.c +++ b/drivers/firmware/arm_scmi/driver.c @@ -2657,6 +2657,7 @@ static int scmi_probe(struct platform_device *pdev) struct scmi_handle *handle; const struct scmi_desc *desc; struct scmi_info *info; + bool coex = IS_ENABLED(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT_COEX); struct device *dev = &pdev->dev; struct device_node *child, *np = dev->of_node; @@ -2731,9 +2732,6 @@ static int scmi_probe(struct platform_device *pdev) dev_warn(dev, "Failed to setup SCMI debugfs.\n"); if (IS_ENABLED(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT)) { - bool coex = - IS_ENABLED(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT_COEX); - ret = scmi_debugfs_raw_mode_setup(info); if (!coex) { if (ret) @@ -2764,6 +2762,8 @@ static int scmi_probe(struct platform_device *pdev) ret = scmi_protocol_acquire(handle, SCMI_PROTOCOL_BASE); if (ret) { dev_err(dev, "unable to communicate with SCMI\n"); + if (coex) + return 0; goto notification_exit; } From 2ab4f4018cb6b8010ca5002c3bdc37783b5d28c2 Mon Sep 17 00:00:00 2001 From: Cristian Marussi Date: Tue, 7 Mar 2023 16:23:24 +0000 Subject: [PATCH 5/9] firmware: arm_scmi: Fix device node validation for mailbox transport When mailboxes are used as a transport it is possible to setup the SCMI transport layer, depending on the underlying channels configuration, to use one or two mailboxes, associated, respectively, to one or two, distinct, shared memory areas: any other combination should be treated as invalid. Add more strict checking of SCMI mailbox transport device node descriptors. Fixes: 5c8a47a5a91d ("firmware: arm_scmi: Make scmi core independent of the transport type") Cc: # 4.19 Signed-off-by: Cristian Marussi Link: https://lore.kernel.org/r/20230307162324.891866-1-cristian.marussi@arm.com Signed-off-by: Sudeep Holla --- drivers/firmware/arm_scmi/mailbox.c | 37 +++++++++++++++++++++++++++++ 1 file changed, 37 insertions(+) diff --git a/drivers/firmware/arm_scmi/mailbox.c b/drivers/firmware/arm_scmi/mailbox.c index 0d9c9538b7f4..112c285deb97 100644 --- a/drivers/firmware/arm_scmi/mailbox.c +++ b/drivers/firmware/arm_scmi/mailbox.c @@ -52,6 +52,39 @@ static bool mailbox_chan_available(struct device_node *of_node, int idx) "#mbox-cells", idx, NULL); } +static int mailbox_chan_validate(struct device *cdev) +{ + int num_mb, num_sh, ret = 0; + struct device_node *np = cdev->of_node; + + num_mb = of_count_phandle_with_args(np, "mboxes", "#mbox-cells"); + num_sh = of_count_phandle_with_args(np, "shmem", NULL); + /* Bail out if mboxes and shmem descriptors are inconsistent */ + if (num_mb <= 0 || num_sh > 2 || num_mb != num_sh) { + dev_warn(cdev, "Invalid channel descriptor for '%s'\n", + of_node_full_name(np)); + return -EINVAL; + } + + if (num_sh > 1) { + struct device_node *np_tx, *np_rx; + + np_tx = of_parse_phandle(np, "shmem", 0); + np_rx = of_parse_phandle(np, "shmem", 1); + /* SCMI Tx and Rx shared mem areas have to be distinct */ + if (!np_tx || !np_rx || np_tx == np_rx) { + dev_warn(cdev, "Invalid shmem descriptor for '%s'\n", + of_node_full_name(np)); + ret = -EINVAL; + } + + of_node_put(np_tx); + of_node_put(np_rx); + } + + return ret; +} + static int mailbox_chan_setup(struct scmi_chan_info *cinfo, struct device *dev, bool tx) { @@ -64,6 +97,10 @@ static int mailbox_chan_setup(struct scmi_chan_info *cinfo, struct device *dev, resource_size_t size; struct resource res; + ret = mailbox_chan_validate(cdev); + if (ret) + return ret; + smbox = devm_kzalloc(dev, sizeof(*smbox), GFP_KERNEL); if (!smbox) return -ENOMEM; From d617808e3b8324eacebabefec49dc75536ee39cc Mon Sep 17 00:00:00 2001 From: Christophe JAILLET Date: Fri, 8 Jul 2022 21:30:01 +0200 Subject: [PATCH 6/9] firmware: arm_scmi: Use the bitmap API to allocate bitmaps Use devm_bitmap_zalloc() instead of hand-writing them. It is less verbose and it improves the semantic. Signed-off-by: Christophe JAILLET Reviewed-by: Cristian Marussi Tested-by: Cristian Marussi Link: https://lore.kernel.org/r/c073b1607ada34d5bde6ce1009179cf15bbf0da3.1657308593.git.christophe.jaillet@wanadoo.fr Signed-off-by: Sudeep Holla --- drivers/firmware/arm_scmi/driver.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c index 15a431639d82..dbc474ff62b7 100644 --- a/drivers/firmware/arm_scmi/driver.c +++ b/drivers/firmware/arm_scmi/driver.c @@ -2221,8 +2221,8 @@ static int __scmi_xfer_info_init(struct scmi_info *sinfo, hash_init(info->pending_xfers); /* Allocate a bitmask sized to hold MSG_TOKEN_MAX tokens */ - info->xfer_alloc_table = devm_kcalloc(dev, BITS_TO_LONGS(MSG_TOKEN_MAX), - sizeof(long), GFP_KERNEL); + info->xfer_alloc_table = devm_bitmap_zalloc(dev, MSG_TOKEN_MAX, + GFP_KERNEL); if (!info->xfer_alloc_table) return -ENOMEM; From b2ccba9e8cdc6fb3985cc227844e7c6af309ffb1 Mon Sep 17 00:00:00 2001 From: Cristian Marussi Date: Sun, 26 Mar 2023 21:34:49 +0100 Subject: [PATCH 7/9] firmware: arm_scmi: Fix xfers allocation on Rx channel Two distinct pools of xfer descriptors are allocated at initialization time: one (Tx) used to provide xfers to track commands and their replies (or delayed replies) and another (Rx) to pick xfers from to be used for processing notifications. Such pools, though, are allocated globally to be used by the whole SCMI instance, they are not allocated per-channel and as such the allocation of notifications xfers cannot be simply skipped if no Rx channel was found for the base protocol common channel, because there could be defined more optional per-protocol dedicated channels that instead support Rx channels. Change the conditional check to skip allocation for the notification pool only if no Rx channel has been detected on any per-channel protocol at all. Fixes: 4ebd8f6dea81 ("firmware: arm_scmi: Add receive buffer support for notifications") Signed-off-by: Cristian Marussi Link: https://lore.kernel.org/r/20230326203449.3492948-1-cristian.marussi@arm.com Signed-off-by: Sudeep Holla --- drivers/firmware/arm_scmi/driver.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c index dbc474ff62b7..e7d97b59963b 100644 --- a/drivers/firmware/arm_scmi/driver.c +++ b/drivers/firmware/arm_scmi/driver.c @@ -2289,7 +2289,7 @@ static int scmi_xfer_info_init(struct scmi_info *sinfo) return ret; ret = __scmi_xfer_info_init(sinfo, &sinfo->tx_minfo); - if (!ret && idr_find(&sinfo->rx_idr, SCMI_PROTOCOL_BASE)) + if (!ret && !idr_is_empty(&sinfo->rx_idr)) ret = __scmi_xfer_info_init(sinfo, &sinfo->rx_minfo); return ret; From 92ac94f7e176bb9f5a9735bc1be6d69e96d4d5c1 Mon Sep 17 00:00:00 2001 From: Cristian Marussi Date: Tue, 4 Apr 2023 12:50:25 +0100 Subject: [PATCH 8/9] dt-bindings: firmware: arm,scmi: Support mailboxes unidirectional channels SCMI defines two kinds of communication channels between the agent and the platform: one bidirectional 'a2p' channel used by the agent to send SCMI commands and synchronously receive the related replies, and an optional 'p2a' unidirectional channel used to asynchronously receive delayed responses and notifications emitted from the platform. When configuring an SCMI transport based on mailboxes, the current binding supports only mailboxes providing bidirectional channels: in such a case one mailbox channel can be easily assigned to each SCMI channel as above described. In case, instead, to have to deal with mailboxes providing only distinct unidirectional channels, it becomes necessary to extend the binding in order to be able to bind 2 distinct unidirectional mailbox channels to the same SCMI 'a2p' channel. Bidirectional and unidirectional channels support for the SCMI mailbox transport can coexist by carefully considering the effective combination of defined 'mboxes' and 'shmem' descriptors. Signed-off-by: Cristian Marussi Reviewed-by: Rob Herring Link: https://lore.kernel.org/r/20230404115026.2828149-2-cristian.marussi@arm.com Signed-off-by: Sudeep Holla --- .../bindings/firmware/arm,scmi.yaml | 48 +++++++++++++++---- 1 file changed, 38 insertions(+), 10 deletions(-) diff --git a/Documentation/devicetree/bindings/firmware/arm,scmi.yaml b/Documentation/devicetree/bindings/firmware/arm,scmi.yaml index 2f7c51c75e85..5824c43e9893 100644 --- a/Documentation/devicetree/bindings/firmware/arm,scmi.yaml +++ b/Documentation/devicetree/bindings/firmware/arm,scmi.yaml @@ -56,17 +56,38 @@ properties: description: Specifies the mailboxes used to communicate with SCMI compliant firmware. - items: - - const: tx - - const: rx + oneOf: + - items: + - const: tx + - const: rx + minItems: 1 + - items: + - const: tx + - const: tx_reply + - const: rx + minItems: 2 mboxes: description: List of phandle and mailbox channel specifiers. It should contain - exactly one or two mailboxes, one for transmitting messages("tx") - and another optional for receiving the notifications("rx") if supported. + exactly one, two or three mailboxes; the first one or two for transmitting + messages ("tx") and another optional ("rx") for receiving notifications + and delayed responses, if supported by the platform. + The number of mailboxes needed for transmitting messages depends on the + type of channels exposed by the specific underlying mailbox controller; + one single channel descriptor is enough if such channel is bidirectional, + while two channel descriptors are needed to represent the SCMI ("tx") + channel if the underlying mailbox channels are of unidirectional type. + The effective combination in numbers of mboxes and shmem descriptors let + the SCMI subsystem determine unambiguosly which type of SCMI channels are + made available by the underlying mailbox controller and how to use them. + 1 mbox / 1 shmem => SCMI TX over 1 mailbox bidirectional channel + 2 mbox / 2 shmem => SCMI TX and RX over 2 mailbox bidirectional channels + 2 mbox / 1 shmem => SCMI TX over 2 mailbox unidirectional channels + 3 mbox / 2 shmem => SCMI TX and RX over 3 mailbox unidirectional channels + Any other combination of mboxes and shmem is invalid. minItems: 1 - maxItems: 2 + maxItems: 3 shmem: description: @@ -228,13 +249,20 @@ $defs: maxItems: 1 mbox-names: - items: - - const: tx - - const: rx + oneOf: + - items: + - const: tx + - const: rx + minItems: 1 + - items: + - const: tx + - const: tx_reply + - const: rx + minItems: 2 mboxes: minItems: 1 - maxItems: 2 + maxItems: 3 shmem: minItems: 1 From 9f68ff79ec2cb303f360a35eef5dd8f1f0f817e1 Mon Sep 17 00:00:00 2001 From: Cristian Marussi Date: Tue, 4 Apr 2023 12:50:26 +0100 Subject: [PATCH 9/9] firmware: arm_scmi: Add support for unidirectional mailbox channels Extend the SCMI transport layer to support mailbox controllers that expose communication channels that are unidirectional by nature. Signed-off-by: Cristian Marussi Link: https://lore.kernel.org/r/20230404115026.2828149-3-cristian.marussi@arm.com Signed-off-by: Sudeep Holla --- drivers/firmware/arm_scmi/mailbox.c | 95 +++++++++++++++++++++++++---- 1 file changed, 84 insertions(+), 11 deletions(-) diff --git a/drivers/firmware/arm_scmi/mailbox.c b/drivers/firmware/arm_scmi/mailbox.c index 112c285deb97..1efa5e9392c4 100644 --- a/drivers/firmware/arm_scmi/mailbox.c +++ b/drivers/firmware/arm_scmi/mailbox.c @@ -19,13 +19,15 @@ * struct scmi_mailbox - Structure representing a SCMI mailbox transport * * @cl: Mailbox Client - * @chan: Transmit/Receive mailbox channel + * @chan: Transmit/Receive mailbox uni/bi-directional channel + * @chan_receiver: Optional Receiver mailbox unidirectional channel * @cinfo: SCMI channel info * @shmem: Transmit/Receive shared memory area */ struct scmi_mailbox { struct mbox_client cl; struct mbox_chan *chan; + struct mbox_chan *chan_receiver; struct scmi_chan_info *cinfo; struct scmi_shared_mem __iomem *shmem; }; @@ -48,30 +50,62 @@ static void rx_callback(struct mbox_client *cl, void *m) static bool mailbox_chan_available(struct device_node *of_node, int idx) { + int num_mb; + + /* + * Just check if bidirrectional channels are involved, and check the + * index accordingly; proper full validation will be made later + * in mailbox_chan_setup(). + */ + num_mb = of_count_phandle_with_args(of_node, "mboxes", "#mbox-cells"); + if (num_mb == 3 && idx == 1) + idx = 2; + return !of_parse_phandle_with_args(of_node, "mboxes", "#mbox-cells", idx, NULL); } -static int mailbox_chan_validate(struct device *cdev) +/** + * mailbox_chan_validate - Validate transport configuration and map channels + * + * @cdev: Reference to the underlying transport device carrying the + * of_node descriptor to analyze. + * @a2p_rx_chan: A reference to an optional unidirectional channel to use + * for replies on the a2p channel. Set as zero if not present. + * @p2a_chan: A reference to the optional p2a channel. + * Set as zero if not present. + * + * At first, validate the transport configuration as described in terms of + * 'mboxes' and 'shmem', then determin which mailbox channel indexes are + * appropriate to be use in the current configuration. + * + * Return: 0 on Success or error + */ +static int mailbox_chan_validate(struct device *cdev, + int *a2p_rx_chan, int *p2a_chan) { int num_mb, num_sh, ret = 0; struct device_node *np = cdev->of_node; num_mb = of_count_phandle_with_args(np, "mboxes", "#mbox-cells"); num_sh = of_count_phandle_with_args(np, "shmem", NULL); + dev_dbg(cdev, "Found %d mboxes and %d shmems !\n", num_mb, num_sh); + /* Bail out if mboxes and shmem descriptors are inconsistent */ - if (num_mb <= 0 || num_sh > 2 || num_mb != num_sh) { - dev_warn(cdev, "Invalid channel descriptor for '%s'\n", - of_node_full_name(np)); + if (num_mb <= 0 || num_sh <= 0 || num_sh > 2 || num_mb > 3 || + (num_mb == 1 && num_sh != 1) || (num_mb == 3 && num_sh != 2)) { + dev_warn(cdev, + "Invalid channel descriptor for '%s' - mbs:%d shm:%d\n", + of_node_full_name(np), num_mb, num_sh); return -EINVAL; } + /* Bail out if provided shmem descriptors do not refer distinct areas */ if (num_sh > 1) { struct device_node *np_tx, *np_rx; np_tx = of_parse_phandle(np, "shmem", 0); np_rx = of_parse_phandle(np, "shmem", 1); - /* SCMI Tx and Rx shared mem areas have to be distinct */ if (!np_tx || !np_rx || np_tx == np_rx) { dev_warn(cdev, "Invalid shmem descriptor for '%s'\n", of_node_full_name(np)); @@ -82,6 +116,29 @@ static int mailbox_chan_validate(struct device *cdev) of_node_put(np_rx); } + /* Calculate channels IDs to use depending on mboxes/shmem layout */ + if (!ret) { + switch (num_mb) { + case 1: + *a2p_rx_chan = 0; + *p2a_chan = 0; + break; + case 2: + if (num_sh == 2) { + *a2p_rx_chan = 0; + *p2a_chan = 1; + } else { + *a2p_rx_chan = 1; + *p2a_chan = 0; + } + break; + case 3: + *a2p_rx_chan = 1; + *p2a_chan = 2; + break; + } + } + return ret; } @@ -92,15 +149,18 @@ static int mailbox_chan_setup(struct scmi_chan_info *cinfo, struct device *dev, struct device *cdev = cinfo->dev; struct scmi_mailbox *smbox; struct device_node *shmem; - int ret, idx = tx ? 0 : 1; + int ret, a2p_rx_chan, p2a_chan, idx = tx ? 0 : 1; struct mbox_client *cl; resource_size_t size; struct resource res; - ret = mailbox_chan_validate(cdev); + ret = mailbox_chan_validate(cdev, &a2p_rx_chan, &p2a_chan); if (ret) return ret; + if (!tx && !p2a_chan) + return -ENODEV; + smbox = devm_kzalloc(dev, sizeof(*smbox), GFP_KERNEL); if (!smbox) return -ENOMEM; @@ -130,15 +190,26 @@ static int mailbox_chan_setup(struct scmi_chan_info *cinfo, struct device *dev, cl->tx_block = false; cl->knows_txdone = tx; - smbox->chan = mbox_request_channel(cl, tx ? 0 : 1); + smbox->chan = mbox_request_channel(cl, tx ? 0 : p2a_chan); if (IS_ERR(smbox->chan)) { ret = PTR_ERR(smbox->chan); if (ret != -EPROBE_DEFER) - dev_err(cdev, "failed to request SCMI %s mailbox\n", - tx ? "Tx" : "Rx"); + dev_err(cdev, + "failed to request SCMI %s mailbox\n", desc); return ret; } + /* Additional unidirectional channel for TX if needed */ + if (tx && a2p_rx_chan) { + smbox->chan_receiver = mbox_request_channel(cl, a2p_rx_chan); + if (IS_ERR(smbox->chan_receiver)) { + ret = PTR_ERR(smbox->chan_receiver); + if (ret != -EPROBE_DEFER) + dev_err(cdev, "failed to request SCMI Tx Receiver mailbox\n"); + return ret; + } + } + cinfo->transport_info = smbox; smbox->cinfo = cinfo; @@ -152,8 +223,10 @@ static int mailbox_chan_free(int id, void *p, void *data) if (smbox && !IS_ERR(smbox->chan)) { mbox_free_channel(smbox->chan); + mbox_free_channel(smbox->chan_receiver); cinfo->transport_info = NULL; smbox->chan = NULL; + smbox->chan_receiver = NULL; smbox->cinfo = NULL; }