From patchwork Tue Mar 14 11:11:34 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "lihuisong (C)" X-Patchwork-Id: 13174100 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A27E0C7618D for ; Tue, 14 Mar 2023 11:13:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230448AbjCNLNy (ORCPT ); Tue, 14 Mar 2023 07:13:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48872 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230346AbjCNLNs (ORCPT ); Tue, 14 Mar 2023 07:13:48 -0400 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 158BE5F525; Tue, 14 Mar 2023 04:13:15 -0700 (PDT) Received: from kwepemm600004.china.huawei.com (unknown [172.30.72.57]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4PbW7Y2ZJ5zrTLF; Tue, 14 Mar 2023 19:11:53 +0800 (CST) Received: from localhost.localdomain (10.28.79.22) by kwepemm600004.china.huawei.com (7.193.23.242) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.21; Tue, 14 Mar 2023 19:12:45 +0800 From: Huisong Li To: , CC: , , , , , , , , , , , , Subject: [PATCH v2 1/2] mailbox: pcc: Add support for platform notification handling Date: Tue, 14 Mar 2023 19:11:34 +0800 Message-ID: <20230314111135.16520-2-lihuisong@huawei.com> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20230314111135.16520-1-lihuisong@huawei.com> References: <20221016034043.52227-1-lihuisong@huawei.com> <20230314111135.16520-1-lihuisong@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.28.79.22] X-ClientProxiedBy: dggems701-chm.china.huawei.com (10.3.19.178) To kwepemm600004.china.huawei.com (7.193.23.242) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org Currently, PCC driver doesn't support the processing of platform notification for type 4 PCC subspaces. According to ACPI specification, if platform sends a notification to OSPM, it must clear the command complete bit and trigger platform interrupt. OSPM needs to check whether the command complete bit is cleared, clear platform interrupt, process command, and then set the command complete and ring doorbell to the Platform. Let us stash the value of the pcc type and use the same while processing the interrupt of the channel. We also need to set the command complete bit and ring doorbell in the interrupt handler for the type 4 channel to complete the communication flow after processing the notification from the Platform. Signed-off-by: Huisong Li --- drivers/mailbox/pcc.c | 50 +++++++++++++++++++++++++++++++++++-------- 1 file changed, 41 insertions(+), 9 deletions(-) diff --git a/drivers/mailbox/pcc.c b/drivers/mailbox/pcc.c index 105d46c9801b..a0a87c480d8b 100644 --- a/drivers/mailbox/pcc.c +++ b/drivers/mailbox/pcc.c @@ -91,6 +91,7 @@ struct pcc_chan_reg { * @cmd_update: PCC register bundle for the command complete update register * @error: PCC register bundle for the error status register * @plat_irq: platform interrupt + * @type: PCC subspace type */ struct pcc_chan_info { struct pcc_mbox_chan chan; @@ -100,12 +101,15 @@ struct pcc_chan_info { struct pcc_chan_reg cmd_update; struct pcc_chan_reg error; int plat_irq; + u8 type; }; #define to_pcc_chan_info(c) container_of(c, struct pcc_chan_info, chan) static struct pcc_chan_info *chan_info; static int pcc_chan_count; +static int pcc_send_data(struct mbox_chan *chan, void *data); + /* * PCC can be used with perf critical drivers such as CPPC * So it makes sense to locally cache the virtual address and @@ -221,6 +225,34 @@ static int pcc_map_interrupt(u32 interrupt, u32 flags) return acpi_register_gsi(NULL, interrupt, trigger, polarity); } +static bool pcc_mbox_cmd_complete_check(struct pcc_chan_info *pchan) +{ + u64 val; + int ret; + + ret = pcc_chan_reg_read(&pchan->cmd_complete, &val); + if (ret) + return false; + + if (!pchan->cmd_complete.gas) + return true; + + /* + * Judge if the channel respond the interrupt based on the value of + * command complete. + */ + val &= pchan->cmd_complete.status_mask; + /* + * If this is PCC slave subspace channel, and the command complete + * bit 0 indicates that Platform is sending a notification and OSPM + * needs to respond this interrupt to process this command. + */ + if (pchan->type == ACPI_PCCT_TYPE_EXT_PCC_SLAVE_SUBSPACE) + return !val; + + return !!val; +} + /** * pcc_mbox_irq - PCC mailbox interrupt handler * @irq: interrupt number @@ -236,17 +268,9 @@ static irqreturn_t pcc_mbox_irq(int irq, void *p) int ret; pchan = chan->con_priv; - - ret = pcc_chan_reg_read(&pchan->cmd_complete, &val); - if (ret) + if (!pcc_mbox_cmd_complete_check(pchan)) return IRQ_NONE; - if (val) { /* Ensure GAS exists and value is non-zero */ - val &= pchan->cmd_complete.status_mask; - if (!val) - return IRQ_NONE; - } - ret = pcc_chan_reg_read(&pchan->error, &val); if (ret) return IRQ_NONE; @@ -262,6 +286,13 @@ static irqreturn_t pcc_mbox_irq(int irq, void *p) mbox_chan_received_data(chan, NULL); + /* + * The PCC slave subspace channel needs to set the command complete bit + * and ring doorbell after processing message. + */ + if (pchan->type == ACPI_PCCT_TYPE_EXT_PCC_SLAVE_SUBSPACE) + pcc_send_data(chan, NULL); + return IRQ_HANDLED; } @@ -692,6 +723,7 @@ static int pcc_mbox_probe(struct platform_device *pdev) pcc_parse_subspace_shmem(pchan, pcct_entry); + pchan->type = pcct_entry->type; pcct_entry = (struct acpi_subtable_header *) ((unsigned long) pcct_entry + pcct_entry->length); } From patchwork Tue Mar 14 11:11:35 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "lihuisong (C)" X-Patchwork-Id: 13174099 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2E880C74A44 for ; Tue, 14 Mar 2023 11:13:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230408AbjCNLNx (ORCPT ); Tue, 14 Mar 2023 07:13:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48884 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230416AbjCNLNs (ORCPT ); Tue, 14 Mar 2023 07:13:48 -0400 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CEAE4746EC; Tue, 14 Mar 2023 04:13:15 -0700 (PDT) Received: from kwepemm600004.china.huawei.com (unknown [172.30.72.54]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4PbW7Y6862zrTLG; Tue, 14 Mar 2023 19:11:53 +0800 (CST) Received: from localhost.localdomain (10.28.79.22) by kwepemm600004.china.huawei.com (7.193.23.242) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.21; Tue, 14 Mar 2023 19:12:46 +0800 From: Huisong Li To: , CC: , , , , , , , , , , , , Subject: [PATCH v2 2/2] mailbox: pcc: Support shared interrupt for multiple subspaces Date: Tue, 14 Mar 2023 19:11:35 +0800 Message-ID: <20230314111135.16520-3-lihuisong@huawei.com> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20230314111135.16520-1-lihuisong@huawei.com> References: <20221016034043.52227-1-lihuisong@huawei.com> <20230314111135.16520-1-lihuisong@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.28.79.22] X-ClientProxiedBy: dggems701-chm.china.huawei.com (10.3.19.178) To kwepemm600004.china.huawei.com (7.193.23.242) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org If the platform acknowledge interrupt is level triggered, then it can be shared by multiple subspaces provided each one has a unique platform interrupt ack preserve and ack set masks. If it can be shared, then we can request the irq with IRQF_SHARED and IRQF_ONESHOT flags. The first one indicating it can be shared and the latter one to keep the interrupt disabled until the hardirq handler finished. Further, since there is no way to detect if the interrupt is for a given channel as the interrupt ack preserve and ack set masks are for clearing the interrupt and not for reading the status(in case Irq Ack register may be write-only on some platforms), we need a way to identify if the given channel is in use and expecting the interrupt. PCC type0, type1 and type5 do not support shared level triggered interrupt. The methods of determining whether a given channel for remaining types should respond to an interrupt are as follows: - type2: Whether the interrupt belongs to a given channel is only determined by the status field in Generic Communications Channel Shared Memory Region, which is done in rx_callback of PCC client. - type3: This channel checks chan_in_use flag first and then checks the command complete bit(value '1' indicates that the command has been completed). - type4: Platform ensure that the default value of the command complete bit corresponding to the type4 channel is '1'. This command complete bit is '0' when receive a platform notification. The new field, 'chan_in_use' is used by the type only support the communication from OSPM to Platform (like type3) and should be completely ignored by other types so as to avoid too many type unnecessary checks in IRQ handler. Signed-off-by: Huisong Li --- drivers/mailbox/pcc.c | 42 +++++++++++++++++++++++++++++++++++++++--- 1 file changed, 39 insertions(+), 3 deletions(-) diff --git a/drivers/mailbox/pcc.c b/drivers/mailbox/pcc.c index a0a87c480d8b..7804dcf72646 100644 --- a/drivers/mailbox/pcc.c +++ b/drivers/mailbox/pcc.c @@ -92,6 +92,13 @@ struct pcc_chan_reg { * @error: PCC register bundle for the error status register * @plat_irq: platform interrupt * @type: PCC subspace type + * @plat_irq_flags: platform interrupt flags + * @chan_in_use: this flag is used just to check if the interrupt needs + * handling when it is shared. Since only one transfer can occur + * at a time and mailbox takes care of locking, this flag can be + * accessed without a lock. Note: the type only support the + * communication from OSPM to Platform, like type3, use it, and + * other types completely ignore it. */ struct pcc_chan_info { struct pcc_mbox_chan chan; @@ -102,6 +109,8 @@ struct pcc_chan_info { struct pcc_chan_reg error; int plat_irq; u8 type; + unsigned int plat_irq_flags; + bool chan_in_use; }; #define to_pcc_chan_info(c) container_of(c, struct pcc_chan_info, chan) @@ -225,6 +234,12 @@ static int pcc_map_interrupt(u32 interrupt, u32 flags) return acpi_register_gsi(NULL, interrupt, trigger, polarity); } +static bool pcc_chan_plat_irq_can_be_shared(struct pcc_chan_info *pchan) +{ + return (pchan->plat_irq_flags & ACPI_PCCT_INTERRUPT_MODE) == + ACPI_LEVEL_SENSITIVE; +} + static bool pcc_mbox_cmd_complete_check(struct pcc_chan_info *pchan) { u64 val; @@ -268,6 +283,10 @@ static irqreturn_t pcc_mbox_irq(int irq, void *p) int ret; pchan = chan->con_priv; + if (pchan->type == ACPI_PCCT_TYPE_EXT_PCC_MASTER_SUBSPACE && + !pchan->chan_in_use) + return IRQ_NONE; + if (!pcc_mbox_cmd_complete_check(pchan)) return IRQ_NONE; @@ -289,9 +308,12 @@ static irqreturn_t pcc_mbox_irq(int irq, void *p) /* * The PCC slave subspace channel needs to set the command complete bit * and ring doorbell after processing message. + * + * The PCC master subspace channel clears chan_in_use to free channel. */ if (pchan->type == ACPI_PCCT_TYPE_EXT_PCC_SLAVE_SUBSPACE) pcc_send_data(chan, NULL); + pchan->chan_in_use = false; return IRQ_HANDLED; } @@ -340,10 +362,13 @@ pcc_mbox_request_channel(struct mbox_client *cl, int subspace_id) spin_unlock_irqrestore(&chan->lock, flags); if (pchan->plat_irq > 0) { + unsigned long irqflags; int rc; - rc = devm_request_irq(dev, pchan->plat_irq, pcc_mbox_irq, 0, - MBOX_IRQ_NAME, chan); + irqflags = pcc_chan_plat_irq_can_be_shared(pchan) ? + IRQF_SHARED | IRQF_ONESHOT : 0; + rc = devm_request_irq(dev, pchan->plat_irq, pcc_mbox_irq, + irqflags, MBOX_IRQ_NAME, chan); if (unlikely(rc)) { dev_err(dev, "failed to register PCC interrupt %d\n", pchan->plat_irq); @@ -405,7 +430,11 @@ static int pcc_send_data(struct mbox_chan *chan, void *data) if (ret) return ret; - return pcc_chan_reg_read_modify_write(&pchan->db); + ret = pcc_chan_reg_read_modify_write(&pchan->db); + if (!ret && pchan->plat_irq > 0) + pchan->chan_in_use = true; + + return ret; } static const struct mbox_chan_ops pcc_chan_ops = { @@ -488,6 +517,7 @@ static int pcc_parse_subspace_irq(struct pcc_chan_info *pchan, pcct_ss->platform_interrupt); return -EINVAL; } + pchan->plat_irq_flags = pcct_ss->flags; if (pcct_ss->header.type == ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE_TYPE2) { struct acpi_pcct_hw_reduced_type2 *pcct2_ss = (void *)pcct_ss; @@ -509,6 +539,12 @@ static int pcc_parse_subspace_irq(struct pcc_chan_info *pchan, "PLAT IRQ ACK"); } + if (pcc_chan_plat_irq_can_be_shared(pchan) && + !pchan->plat_irq_ack.gas) { + pr_err("PCC subspace has level IRQ with no ACK register\n"); + return -EINVAL; + } + return ret; }