From patchwork Tue Apr 12 09:49:43 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Pali_Roh=C3=A1r?= X-Patchwork-Id: 12810471 X-Patchwork-Delegate: lorenzo.pieralisi@arm.com 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 DB4FEC433F5 for ; Tue, 12 Apr 2022 10:56:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231945AbiDLK6z (ORCPT ); Tue, 12 Apr 2022 06:58:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44904 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1377249AbiDLK43 (ORCPT ); Tue, 12 Apr 2022 06:56:29 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 693B18FE4C; Tue, 12 Apr 2022 02:50:31 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id F035C60BC8; Tue, 12 Apr 2022 09:50:30 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 39744C385A8; Tue, 12 Apr 2022 09:50:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1649757030; bh=vzWBAbR4Oux6P/RO30qmN2wLxTgTR+gOm30Ed6V+lZE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=IlSS1wmFKrWzkfJi4hldavcKISvxjfNC+VXxqhdNioR67UER5LhU1AAwVB0tbvlvq mnj+pv5tER0pKEBnvdr6hFBBBmW1I1Z8QnlISWvKeiVybuabAYtcnxWYy+oq1h4GhF Sg+FA+pB1xRO4S5fUfp7NKll8iY3fCfurs+ji78M+NbH9rdTb2PRlmgCmCL7wdi1rv F3OaMOm9BFdhM07XH5oQe4QkOp5vgnrr5oXAg+6yOSpF5f72B5y/YOHAhsgUIn/chz UnklEes3OVA89erBB/kCg9Dnp6+JDv1XHVlA+JGLDlsD67sgI+oePSR94CzXbEHxmL 4IqDnvutV1j9g== Received: by pali.im (Postfix) id D3C492AB2; Tue, 12 Apr 2022 11:50:27 +0200 (CEST) From: =?utf-8?q?Pali_Roh=C3=A1r?= To: Lorenzo Pieralisi , Bjorn Helgaas , Rob Herring , Andrew Lunn , Thomas Petazzoni , =?utf-8?q?Krzysztof_Wilczy?= =?utf-8?q?=C5=84ski?= , =?utf-8?q?Marek_Beh=C3=BAn?= , Russell King Cc: linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH v5 1/4] PCI: Add PCI_EXP_SLTCTL_ASPL_DISABLE macro Date: Tue, 12 Apr 2022 11:49:43 +0200 Message-Id: <20220412094946.27069-2-pali@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20220412094946.27069-1-pali@kernel.org> References: <20220412094946.27069-1-pali@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Add macro defining Auto Slot Power Limit Disable bit in Slot Control Register. Signed-off-by: Pali Rohár Signed-off-by: Marek Behún Acked-by: Bjorn Helgaas --- include/uapi/linux/pci_regs.h | 1 + 1 file changed, 1 insertion(+) diff --git a/include/uapi/linux/pci_regs.h b/include/uapi/linux/pci_regs.h index bee1a9ed6e66..108f8523fa04 100644 --- a/include/uapi/linux/pci_regs.h +++ b/include/uapi/linux/pci_regs.h @@ -616,6 +616,7 @@ #define PCI_EXP_SLTCTL_PWR_OFF 0x0400 /* Power Off */ #define PCI_EXP_SLTCTL_EIC 0x0800 /* Electromechanical Interlock Control */ #define PCI_EXP_SLTCTL_DLLSCE 0x1000 /* Data Link Layer State Changed Enable */ +#define PCI_EXP_SLTCTL_ASPL_DISABLE 0x2000 /* Auto Slot Power Limit Disable */ #define PCI_EXP_SLTCTL_IBPD_DISABLE 0x4000 /* In-band PD disable */ #define PCI_EXP_SLTSTA 0x1a /* Slot Status */ #define PCI_EXP_SLTSTA_ABP 0x0001 /* Attention Button Pressed */ From patchwork Tue Apr 12 09:49:44 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Pali_Roh=C3=A1r?= X-Patchwork-Id: 12810468 X-Patchwork-Delegate: lorenzo.pieralisi@arm.com 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 6C8AAC433F5 for ; Tue, 12 Apr 2022 10:56:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240567AbiDLK6j (ORCPT ); Tue, 12 Apr 2022 06:58:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44110 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1377356AbiDLK4h (ORCPT ); Tue, 12 Apr 2022 06:56:37 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9767A652E3; Tue, 12 Apr 2022 02:50:33 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 16E21B81BB6; Tue, 12 Apr 2022 09:50:32 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A89F2C385AC; Tue, 12 Apr 2022 09:50:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1649757030; bh=dtnf8XsUhj4Osmhrrm08Dt6iD1UNUzpBusiWKcRHhvA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=sgjz/h69Zzm0IbBc4hN20acNhDIQ01/cZcuXUONWZL+DHD66VXgkoGOSRTymU+XcH 2LefS2l+jCeD1nkXXaRa0DokpNc4BbTeXW3IaBGNha8QG2wXmEqmxSPViXeRdZsHGp +0DnZ28COqc9mV7B3x2/A3utLWokfnxZoMTxQK7Lgffo72ukL4tZrxg8llezKL6snR B9uf9RVd93AptBUT2LGOeJwDPAOB3IGtOFUP1CKNSg0FxqAGgJ+rf6aOTbF/MfPI0e ME3AWRJPJp5V0Fr311sN24BT7hBUrPDtzZWpn2dMosyauzKGjWj/mTeFkL7TIvbsn8 rj15zmdxoHo5w== Received: by pali.im (Postfix) id 4A1632AB3; Tue, 12 Apr 2022 11:50:28 +0200 (CEST) From: =?utf-8?q?Pali_Roh=C3=A1r?= To: Lorenzo Pieralisi , Bjorn Helgaas , Rob Herring , Andrew Lunn , Thomas Petazzoni , =?utf-8?q?Krzysztof_Wilczy?= =?utf-8?q?=C5=84ski?= , =?utf-8?q?Marek_Beh=C3=BAn?= , Russell King Cc: linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH v5 2/4] dt-bindings: Add 'slot-power-limit-milliwatt' PCIe port property Date: Tue, 12 Apr 2022 11:49:44 +0200 Message-Id: <20220412094946.27069-3-pali@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20220412094946.27069-1-pali@kernel.org> References: <20220412094946.27069-1-pali@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org This property specifies slot power limit in mW unit. It is a form-factor and board specific value and must be initialized by hardware. Some PCIe controllers delegate this work to software to allow hardware flexibility and therefore this property basically specifies what should host bridge program into PCIe Slot Capabilities registers. The property needs to be specified in mW unit instead of the special format defined by Slot Capabilities (which encodes scaling factor or different unit). Host drivers should convert the value from mW to needed format. Signed-off-by: Pali Rohár Signed-off-by: Marek Behún --- This change was already accepted into dt-schema repo by Rob Herring: https://github.com/devicetree-org/dt-schema/pull/66 --- Documentation/devicetree/bindings/pci/pci.txt | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/Documentation/devicetree/bindings/pci/pci.txt b/Documentation/devicetree/bindings/pci/pci.txt index 6a8f2874a24d..b0cc133ed00d 100644 --- a/Documentation/devicetree/bindings/pci/pci.txt +++ b/Documentation/devicetree/bindings/pci/pci.txt @@ -32,6 +32,12 @@ driver implementation may support the following properties: root port to downstream device and host bridge drivers can do programming which depends on CLKREQ signal existence. For example, programming root port not to advertise ASPM L1 Sub-States support if there is no CLKREQ signal. +- slot-power-limit-milliwatt: + If present, this property specifies slot power limit in milliwatts. Host + drivers can parse this property and use it for programming Root Port or host + bridge, or for composing and sending PCIe Set_Slot_Power_Limit messages + through the Root Port or host bridge when transitioning PCIe link from a + non-DL_Up Status to a DL_Up Status. PCI-PCI Bridge properties ------------------------- From patchwork Tue Apr 12 09:49:45 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Pali_Roh=C3=A1r?= X-Patchwork-Id: 12810470 X-Patchwork-Delegate: lorenzo.pieralisi@arm.com 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 883D9C433FE for ; Tue, 12 Apr 2022 10:56:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236205AbiDLK6w (ORCPT ); Tue, 12 Apr 2022 06:58:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45668 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1377325AbiDLK4h (ORCPT ); Tue, 12 Apr 2022 06:56:37 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9154D8FE58; Tue, 12 Apr 2022 02:50:32 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id D0164618A8; Tue, 12 Apr 2022 09:50:31 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E2C5DC385B0; Tue, 12 Apr 2022 09:50:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1649757031; bh=VmyOGDFwXHb+w1t6LNTfW65lcqPUottzbY1nKtknM4A=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=VSnnJ4oFqa3jHeP0M5nJU4nexVvb9AVT95HXFNGPdLEU3iWPK/+fDAgjmJBYqQrfj GsSbb2BxPOLMEKeVy0BBSBxULv9uRFKomJDrG9VWzh3QsQ79qubIqJcsgCNB4yXDZP k86wmWeRJNKV4qs9YDwgW7SG8C9FquJolp8h4xmcvS6wFxt8gUlNXas/wtay8iNjjO ewAxL0A6geCdGYBg7aZ+oZFGdwYBO5XdEyQCEter9hjFMYVfwEJBN1mrUmDq6se7Pq bhGr3MRMqVq21Ofh6bxSCwrmRZWO/xEHo/IiETu+tCaP3igvypqdDnI3jmnGObzoQV uG94SyYY36nQA== Received: by pali.im (Postfix) id B04B02AB8; Tue, 12 Apr 2022 11:50:28 +0200 (CEST) From: =?utf-8?q?Pali_Roh=C3=A1r?= To: Lorenzo Pieralisi , Bjorn Helgaas , Rob Herring , Andrew Lunn , Thomas Petazzoni , =?utf-8?q?Krzysztof_Wilczy?= =?utf-8?q?=C5=84ski?= , =?utf-8?q?Marek_Beh=C3=BAn?= , Russell King Cc: linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH v5 3/4] PCI: Add function for parsing 'slot-power-limit-milliwatt' DT property Date: Tue, 12 Apr 2022 11:49:45 +0200 Message-Id: <20220412094946.27069-4-pali@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20220412094946.27069-1-pali@kernel.org> References: <20220412094946.27069-1-pali@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Add function of_pci_get_slot_power_limit(), which parses the 'slot-power-limit-milliwatt' DT property, returning the value in milliwatts and in format ready for the PCIe Slot Capabilities Register. Signed-off-by: Pali Rohár Signed-off-by: Marek Behún Reviewed-by: Rob Herring Reviewed-by: Bjorn Helgaas --- Changes in v4: * Set 239 W when DT slot-power-limit-milliwatt is between 239 W and 250 W * Fix returning power limit value Changes in v3: * Set 600 W when DT slot-power-limit-milliwatt > 600 W Changes in v2: * Added support for PCIe 6.0 slot power limit encodings * Round down slot power limit value --- drivers/pci/of.c | 70 +++++++++++++++++++++++++++++++++++++++++++++++ drivers/pci/pci.h | 15 ++++++++++ 2 files changed, 85 insertions(+) diff --git a/drivers/pci/of.c b/drivers/pci/of.c index cb2e8351c2cc..6c1b81304665 100644 --- a/drivers/pci/of.c +++ b/drivers/pci/of.c @@ -633,3 +633,73 @@ int of_pci_get_max_link_speed(struct device_node *node) return max_link_speed; } EXPORT_SYMBOL_GPL(of_pci_get_max_link_speed); + +/** + * of_pci_get_slot_power_limit - Parses the "slot-power-limit-milliwatt" + * property. + * + * @node: device tree node with the slot power limit information + * @slot_power_limit_value: pointer where the value should be stored in PCIe + * Slot Capabilities Register format + * @slot_power_limit_scale: pointer where the scale should be stored in PCIe + * Slot Capabilities Register format + * + * Returns the slot power limit in milliwatts and if @slot_power_limit_value + * and @slot_power_limit_scale pointers are non-NULL, fills in the value and + * scale in format used by PCIe Slot Capabilities Register. + * + * If the property is not found or is invalid, returns 0. + */ +u32 of_pci_get_slot_power_limit(struct device_node *node, + u8 *slot_power_limit_value, + u8 *slot_power_limit_scale) +{ + u32 slot_power_limit_mw; + u8 value, scale; + + if (of_property_read_u32(node, "slot-power-limit-milliwatt", + &slot_power_limit_mw)) + slot_power_limit_mw = 0; + + /* Calculate Slot Power Limit Value and Slot Power Limit Scale */ + if (slot_power_limit_mw == 0) { + value = 0x00; + scale = 0; + } else if (slot_power_limit_mw <= 255) { + value = slot_power_limit_mw; + scale = 3; + } else if (slot_power_limit_mw <= 255*10) { + value = slot_power_limit_mw / 10; + scale = 2; + slot_power_limit_mw = slot_power_limit_mw / 10 * 10; + } else if (slot_power_limit_mw <= 255*100) { + value = slot_power_limit_mw / 100; + scale = 1; + slot_power_limit_mw = slot_power_limit_mw / 100 * 100; + } else if (slot_power_limit_mw <= 239*1000) { + value = slot_power_limit_mw / 1000; + scale = 0; + slot_power_limit_mw = slot_power_limit_mw / 1000 * 1000; + } else if (slot_power_limit_mw < 250*1000) { + value = 0xEF; + scale = 0; + slot_power_limit_mw = 239*1000; + } else if (slot_power_limit_mw <= 600*1000) { + value = 0xF0 + (slot_power_limit_mw / 1000 - 250) / 25; + scale = 0; + slot_power_limit_mw = slot_power_limit_mw / (1000*25) * (1000*25); + } else { + value = 0xFE; + scale = 0; + slot_power_limit_mw = 600*1000; + } + + if (slot_power_limit_value) + *slot_power_limit_value = value; + + if (slot_power_limit_scale) + *slot_power_limit_scale = scale; + + return slot_power_limit_mw; +} +EXPORT_SYMBOL_GPL(of_pci_get_slot_power_limit); diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index 3d60cabde1a1..e10cdec6c56e 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -627,6 +627,9 @@ struct device_node; int of_pci_parse_bus_range(struct device_node *node, struct resource *res); int of_get_pci_domain_nr(struct device_node *node); int of_pci_get_max_link_speed(struct device_node *node); +u32 of_pci_get_slot_power_limit(struct device_node *node, + u8 *slot_power_limit_value, + u8 *slot_power_limit_scale); void pci_set_of_node(struct pci_dev *dev); void pci_release_of_node(struct pci_dev *dev); void pci_set_bus_of_node(struct pci_bus *bus); @@ -653,6 +656,18 @@ of_pci_get_max_link_speed(struct device_node *node) return -EINVAL; } +static inline u32 +of_pci_get_slot_power_limit(struct device_node *node, + u8 *slot_power_limit_value, + u8 *slot_power_limit_scale) +{ + if (slot_power_limit_value) + *slot_power_limit_value = 0; + if (slot_power_limit_scale) + *slot_power_limit_scale = 0; + return 0; +} + static inline void pci_set_of_node(struct pci_dev *dev) { } static inline void pci_release_of_node(struct pci_dev *dev) { } static inline void pci_set_bus_of_node(struct pci_bus *bus) { } From patchwork Tue Apr 12 09:49:46 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Pali_Roh=C3=A1r?= X-Patchwork-Id: 12810467 X-Patchwork-Delegate: lorenzo.pieralisi@arm.com 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 4519EC433EF for ; Tue, 12 Apr 2022 10:56:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239652AbiDLK6g (ORCPT ); Tue, 12 Apr 2022 06:58:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38822 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1377400AbiDLK4h (ORCPT ); Tue, 12 Apr 2022 06:56:37 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3B0568FE65; Tue, 12 Apr 2022 02:50:34 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id DB204B81BE0; Tue, 12 Apr 2022 09:50:32 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 472F4C385A5; Tue, 12 Apr 2022 09:50:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1649757031; bh=qjB85O8DbKC3TvZDkCMMn0qt2Y9QJcIc9o8iYjgvdPE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=B3z/sKKRaIf4WlVMtQFgs2+uZ3KVUCYiJcROQYqjKX8aRVHI90YihGtFeyiK0wAOF s6cR96hKyAMd0kRyYgXDyi4HHizJ8SI4z46vGxYn4vcFIHzUsG45Qevmqj78hxsP6I gRC69Ui5pfhKULGjQrD0tK0RWtniMRydQu6A6SKneZYsT5D1hxtYkAVHrWQfisM6ml QC8Y5d9Ya5LOSyxYW0OZuXCS9JNi+F7J8cKfRquKUaHEryL/tZdTz7SdZaZRQfzo1z Vi4pDGxunliVwF/T2JNFAvcfUxbBoNe6W6KfipNP5X2NxvHpwVTQSiZ+xJBO7EykNv Ypl2A3ore+AmA== Received: by pali.im (Postfix) id 268C42B53; Tue, 12 Apr 2022 11:50:29 +0200 (CEST) From: =?utf-8?q?Pali_Roh=C3=A1r?= To: Lorenzo Pieralisi , Bjorn Helgaas , Rob Herring , Andrew Lunn , Thomas Petazzoni , =?utf-8?q?Krzysztof_Wilczy?= =?utf-8?q?=C5=84ski?= , =?utf-8?q?Marek_Beh=C3=BAn?= , Russell King Cc: linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH v5 4/4] PCI: mvebu: Add support for sending Set_Slot_Power_Limit message Date: Tue, 12 Apr 2022 11:49:46 +0200 Message-Id: <20220412094946.27069-5-pali@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20220412094946.27069-1-pali@kernel.org> References: <20220412094946.27069-1-pali@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org If DT supplies the 'slot-power-limit-milliwatt' property, program the value in the Slot Power Limit in the Slot Capabilities register and program the Root Port to send a Set_Slot_Power_Limit Message when the Link transitions to DL_Up. Signed-off-by: Pali Rohár Reviewed-by: Rob Herring --- Changes in v5: * Fix compile error due to wrong patch rebasing Changes in v2: * Fix handling of slot power limit with scale x1.0 (0x00 value) * Use FIELD_PREP instead of _SHIFT macros * Changed commit message to Bjorn's suggestion * Changed comments in the code to match PCIe spec * Preserve user settings of PCI_EXP_SLTCTL_ASPL_DISABLE bit --- drivers/pci/controller/pci-mvebu.c | 97 ++++++++++++++++++++++++++++-- 1 file changed, 92 insertions(+), 5 deletions(-) diff --git a/drivers/pci/controller/pci-mvebu.c b/drivers/pci/controller/pci-mvebu.c index a75d2b9196f9..a9678d658c2a 100644 --- a/drivers/pci/controller/pci-mvebu.c +++ b/drivers/pci/controller/pci-mvebu.c @@ -8,6 +8,7 @@ #include #include #include +#include #include #include #include @@ -66,6 +67,12 @@ #define PCIE_STAT_BUS 0xff00 #define PCIE_STAT_DEV 0x1f0000 #define PCIE_STAT_LINK_DOWN BIT(0) +#define PCIE_SSPL_OFF 0x1a0c +#define PCIE_SSPL_VALUE_SHIFT 0 +#define PCIE_SSPL_VALUE_MASK GENMASK(7, 0) +#define PCIE_SSPL_SCALE_SHIFT 8 +#define PCIE_SSPL_SCALE_MASK GENMASK(9, 8) +#define PCIE_SSPL_ENABLE BIT(16) #define PCIE_RC_RTSTA 0x1a14 #define PCIE_DEBUG_CTRL 0x1a60 #define PCIE_DEBUG_SOFT_RESET BIT(20) @@ -111,6 +118,8 @@ struct mvebu_pcie_port { struct mvebu_pcie_window iowin; u32 saved_pcie_stat; struct resource regs; + u8 slot_power_limit_value; + u8 slot_power_limit_scale; struct irq_domain *intx_irq_domain; raw_spinlock_t irq_lock; int intx_irq; @@ -239,7 +248,7 @@ static void mvebu_pcie_setup_wins(struct mvebu_pcie_port *port) static void mvebu_pcie_setup_hw(struct mvebu_pcie_port *port) { - u32 ctrl, lnkcap, cmd, dev_rev, unmask; + u32 ctrl, lnkcap, cmd, dev_rev, unmask, sspl; /* Setup PCIe controller to Root Complex mode. */ ctrl = mvebu_readl(port, PCIE_CTRL_OFF); @@ -292,6 +301,20 @@ static void mvebu_pcie_setup_hw(struct mvebu_pcie_port *port) /* Point PCIe unit MBUS decode windows to DRAM space. */ mvebu_pcie_setup_wins(port); + /* + * Program Root Port to automatically send Set_Slot_Power_Limit + * PCIe Message when changing status from Dl_Down to Dl_Up and valid + * slot power limit was specified. + */ + sspl = mvebu_readl(port, PCIE_SSPL_OFF); + sspl &= ~(PCIE_SSPL_VALUE_MASK | PCIE_SSPL_SCALE_MASK | PCIE_SSPL_ENABLE); + if (port->slot_power_limit_value) { + sspl |= port->slot_power_limit_value << PCIE_SSPL_VALUE_SHIFT; + sspl |= port->slot_power_limit_scale << PCIE_SSPL_SCALE_SHIFT; + sspl |= PCIE_SSPL_ENABLE; + } + mvebu_writel(port, sspl, PCIE_SSPL_OFF); + /* Mask all interrupt sources. */ mvebu_writel(port, ~PCIE_INT_ALL_MASK, PCIE_INT_UNMASK_OFF); @@ -628,9 +651,24 @@ mvebu_pci_bridge_emul_pcie_conf_read(struct pci_bridge_emul *bridge, (PCI_EXP_LNKSTA_DLLLA << 16) : 0); break; - case PCI_EXP_SLTCTL: - *value = PCI_EXP_SLTSTA_PDS << 16; + case PCI_EXP_SLTCTL: { + u16 slotctl = le16_to_cpu(bridge->pcie_conf.slotctl); + u16 slotsta = le16_to_cpu(bridge->pcie_conf.slotsta); + u32 val = 0; + /* + * When slot power limit was not specified in DT then + * ASPL_DISABLE bit is stored only in emulated config space. + * Otherwise reflect status of PCIE_SSPL_ENABLE bit in HW. + */ + if (!port->slot_power_limit_value) + val |= slotctl & PCI_EXP_SLTCTL_ASPL_DISABLE; + else if (!(mvebu_readl(port, PCIE_SSPL_OFF) & PCIE_SSPL_ENABLE)) + val |= PCI_EXP_SLTCTL_ASPL_DISABLE; + /* This callback is 32-bit and in high bits is slot status. */ + val |= slotsta << 16; + *value = val; break; + } case PCI_EXP_RTSTA: *value = mvebu_readl(port, PCIE_RC_RTSTA); @@ -774,6 +812,22 @@ mvebu_pci_bridge_emul_pcie_conf_write(struct pci_bridge_emul *bridge, mvebu_writel(port, new, PCIE_CAP_PCIEXP + PCI_EXP_LNKCTL); break; + case PCI_EXP_SLTCTL: + /* + * Allow to change PCIE_SSPL_ENABLE bit only when slot power + * limit was specified in DT and configured into HW. + */ + if ((mask & PCI_EXP_SLTCTL_ASPL_DISABLE) && + port->slot_power_limit_value) { + u32 sspl = mvebu_readl(port, PCIE_SSPL_OFF); + if (new & PCI_EXP_SLTCTL_ASPL_DISABLE) + sspl &= ~PCIE_SSPL_ENABLE; + else + sspl |= PCIE_SSPL_ENABLE; + mvebu_writel(port, sspl, PCIE_SSPL_OFF); + } + break; + case PCI_EXP_RTSTA: /* * PME Status bit in Root Status Register (PCIE_RC_RTSTA) @@ -868,8 +922,26 @@ static int mvebu_pci_bridge_emul_init(struct mvebu_pcie_port *port) /* * Older mvebu hardware provides PCIe Capability structure only in * version 1. New hardware provides it in version 2. + * Enable slot support which is emulated. */ - bridge->pcie_conf.cap = cpu_to_le16(pcie_cap_ver); + bridge->pcie_conf.cap = cpu_to_le16(pcie_cap_ver | PCI_EXP_FLAGS_SLOT); + + /* + * Set Presence Detect State bit permanently as there is no support for + * unplugging PCIe card from the slot. Assume that PCIe card is always + * connected in slot. + * + * Set physical slot number to port+1 as mvebu ports are indexed from + * zero and zero value is reserved for ports within the same silicon + * as Root Port which is not mvebu case. + * + * Also set correct slot power limit. + */ + bridge->pcie_conf.slotcap = cpu_to_le32( + FIELD_PREP(PCI_EXP_SLTCAP_SPLV, port->slot_power_limit_value) | + FIELD_PREP(PCI_EXP_SLTCAP_SPLS, port->slot_power_limit_scale) | + FIELD_PREP(PCI_EXP_SLTCAP_PSN, port->port+1)); + bridge->pcie_conf.slotsta = cpu_to_le16(PCI_EXP_SLTSTA_PDS); bridge->subsystem_vendor_id = ssdev_id & 0xffff; bridge->subsystem_id = ssdev_id >> 16; @@ -1191,6 +1263,7 @@ static int mvebu_pcie_parse_port(struct mvebu_pcie *pcie, { struct device *dev = &pcie->pdev->dev; enum of_gpio_flags flags; + u32 slot_power_limit; int reset_gpio, ret; u32 num_lanes; @@ -1291,6 +1364,15 @@ static int mvebu_pcie_parse_port(struct mvebu_pcie *pcie, port->reset_gpio = gpio_to_desc(reset_gpio); } + slot_power_limit = of_pci_get_slot_power_limit(child, + &port->slot_power_limit_value, + &port->slot_power_limit_scale); + if (slot_power_limit) + dev_info(dev, "%s: Slot power limit %u.%uW\n", + port->name, + slot_power_limit / 1000, + (slot_power_limit / 100) % 10); + port->clk = of_clk_get_by_name(child, NULL); if (IS_ERR(port->clk)) { dev_err(dev, "%s: cannot get clock\n", port->name); @@ -1587,7 +1669,7 @@ static int mvebu_pcie_remove(struct platform_device *pdev) { struct mvebu_pcie *pcie = platform_get_drvdata(pdev); struct pci_host_bridge *bridge = pci_host_bridge_from_priv(pcie); - u32 cmd; + u32 cmd, sspl; int i; /* Remove PCI bus with all devices. */ @@ -1624,6 +1706,11 @@ static int mvebu_pcie_remove(struct platform_device *pdev) /* Free config space for emulated root bridge. */ pci_bridge_emul_cleanup(&port->bridge); + /* Disable sending Set_Slot_Power_Limit PCIe Message. */ + sspl = mvebu_readl(port, PCIE_SSPL_OFF); + sspl &= ~(PCIE_SSPL_VALUE_MASK | PCIE_SSPL_SCALE_MASK | PCIE_SSPL_ENABLE); + mvebu_writel(port, sspl, PCIE_SSPL_OFF); + /* Disable and clear BARs and windows. */ mvebu_pcie_disable_wins(port);