From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 550522BEFF0; Wed, 15 Oct 2025 08:02:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760515351; cv=none; b=oAgXOF5Q21Kw6XxwppH+wIopyVnO/X0KwCXUxqO2i2xaSJlwdrMw9ru3oBtz18G5NyDSD4HQTYOAa6D0n97Z/SAkAmR/Kug1EC1Klwwof3NffnjikDWgdNHfsbRgvaFliTUjEhZI0dkMFJRPEloy6GM3nND47e9WyFKJ09jsMi8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760515351; c=relaxed/simple; bh=5ugmTtA9TV2ng/2i8o/Bv7Qs7iLX0E4gKXufe21cP10=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=ebhwerreS50ZAVumeZ0w9DrxyeDMo5j8AB0TDc/gWG3bB6PLSGu4L1rBbLcHwkRPtHxbDAzP8KvwvndsDeCClUtwClF7UEp8l7fk/WTvkPOKP7YKwcZ5Kq/as2bLjYjwtKALnjqGTP0LcwKuC7ZbfdLi14PDM4pHYcMLd3mNNac= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=TAFAN/mN; arc=none smtp.client-ip=192.198.163.18 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="TAFAN/mN" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1760515350; x=1792051350; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=5ugmTtA9TV2ng/2i8o/Bv7Qs7iLX0E4gKXufe21cP10=; b=TAFAN/mNzR/uBx+ejSEtufiTNjFBoZfiipCmslzEcfmjN1Zp685SCVUW gUAgc3mpvWO+v1/xFrLHtQeS3eDZ+QFE87QrYWNVcxLS+Pa/7NQ12LGhx GpZjmx/hJoXnyQ73+BNpqUsASE4Vbq92zDNECcOTavOhiupMoRcY+Ztil pmS8mE62p+LKT0WzxjlhxPdmKWLX8K0d65KM/zMaHzSC9RMXh6C8/ZWMv r5+cqJx4rtrwBZtlWrsrEx7YqKDGNmPnoAZjgm6fk2LAh8bNhnXguukl/ nLDCt+b4HphrCGKuIDn8ytcb6KVZMGr8EeeScbP1QlPBedIU2BJNL4miX w==; X-CSE-ConnectionGUID: XpXT70pZS7OUmfE14rYG8w== X-CSE-MsgGUID: gVRB5lamSN29K/tr8KpgSg== X-IronPort-AV: E=McAfee;i="6800,10657,11582"; a="61891438" X-IronPort-AV: E=Sophos;i="6.19,230,1754982000"; d="scan'208";a="61891438" Received: from fmviesa002.fm.intel.com ([10.60.135.142]) by fmvoesa112.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Oct 2025 01:02:29 -0700 X-CSE-ConnectionGUID: lM6xYwq/Q6eAPR/HN3/nSQ== X-CSE-MsgGUID: KYyik1rPREy11JXzNox0GQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.19,230,1754982000"; d="scan'208";a="205805347" Received: from bnilawar-desk2.iind.intel.com ([10.190.239.41]) by fmviesa002-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Oct 2025 01:02:25 -0700 From: Badal Nilawar To: intel-xe@lists.freedesktop.org, linux-acpi@vger.kernel.org, linux-pci@vger.kernel.org Cc: anshuman.gupta@intel.com, rafael@kernel.org, lenb@kernel.org, bhelgaas@google.com, ilpo.jarvinen@linux.intel.com, lucas.demarchi@intel.com, rodrigo.vivi@intel.com, varun.gupta@intel.com, ville.syrjala@linux.intel.com, uma.shankar@intel.com, karthik.poosa@intel.com Subject: [PATCH v5 01/12] PCI/ACPI: Add D3cold Aux Power Limit_DSM method Date: Wed, 15 Oct 2025 13:36:59 +0530 Message-Id: <20251015080710.1468409-2-badal.nilawar@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20251015080710.1468409-1-badal.nilawar@intel.com> References: <20251015080710.1468409-1-badal.nilawar@intel.com> Precedence: bulk X-Mailing-List: linux-acpi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Anshuman Gupta Implement _DSM method 0Ah, as per PCI Firmware r3.3, sec 4.6.10, to request auxiliary power required by the device when in D3cold state. Note that this implementation assumes only a single device below the Downstream Port will request for Aux Power Limit under a given Root Port/Downstream Port because it does not track and aggregate requests from all child devices below the Downstream Port as required by PCI Firmware r3.3, sec 4.6.10. Co-developed-by: Badal Nilawar Signed-off-by: Badal Nilawar Signed-off-by: Anshuman Gupta --- V2(Bjorn/Rafael): - Call acpi_dsm_check() to find method 0Ah supported - Return retry interval to caller V3(Kuppuswamy) - Add NULL check for retry interval V4 - Define enums for aux power request status (Rafael) - Add Co-developed-by and clean up Signed-off-by (Kappuswamy) (Bjorn) - Instead of root pci device pass the pci device of driver, traverse up the tree and discover _DSM - Allow only function 0 of device to request aux power - Allow retry_interval to be NULL - Refine commit message and function description --- drivers/pci/pci-acpi.c | 114 +++++++++++++++++++++++++++++++++++++++ include/linux/pci-acpi.h | 9 ++++ 2 files changed, 123 insertions(+) diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c index 9369377725fa..c7eab1e75dd5 100644 --- a/drivers/pci/pci-acpi.c +++ b/drivers/pci/pci-acpi.c @@ -1418,6 +1418,120 @@ static void pci_acpi_optimize_delay(struct pci_dev *pdev, ACPI_FREE(obj); } +static struct pci_dev *pci_acpi_check_dsm(struct pci_dev *dev, u64 rev, u64 funcs) +{ + struct pci_dev *bdev; + acpi_handle handle; + + if (!dev) + return ERR_PTR(-EINVAL); + + bdev = dev; + while (bdev) { + handle = ACPI_HANDLE(&bdev->dev); + if (handle && acpi_check_dsm(handle, &pci_acpi_dsm_guid, rev, 1 << funcs)) + return bdev; + + bdev = pci_upstream_bridge(bdev); + } + + return ERR_PTR(-ENODEV); +} + +enum aux_pwr_req_status { + AUX_PWR_REQ_DENIED = 0x0, + AUX_PWR_REQ_GRANTED = 0x1, + AUX_PWR_REQ_NO_MAIN_PWR_REMOVAL = 0x2, + AUX_PWR_REQ_RETRY_INTERVAL_MIN = 0x11, + AUX_PWR_REQ_RETRY_INTERVAL_MAX = 0x1F +}; + +/** + * pci_acpi_request_d3cold_aux_power - Request aux power while device is in D3cold + * @dev: PCI device instance + * @requested_mw: Requested auxiliary power in milliwatts + * @retry_interval: Retry interval returned by platform to retry auxiliary + * power request + * + * Request auxilary power to platform firmware, via Root Port/Switch Downstream + * Port ACPI _DSM Function 0Ah, needed for the PCI device when it is in D3cold. + * Evaluate the _DSM and handle the response accordingly. + * + * For Multi-Function Devices, driver for Function 0 is required to report an + * aggregate power requirement covering all functions contained within the + * device. + * + * Note: Aggregation across multiple child devices beneath the Root/Switch Downstream + * Port is not supported. + * + * Return: Returns 0 on success and errno on failure. + */ +int pci_acpi_request_d3cold_aux_power(struct pci_dev *dev, u32 requested_mw, + u32 *retry_interval) +{ + union acpi_object in_obj = { + .integer.type = ACPI_TYPE_INTEGER, + .integer.value = requested_mw, + }; + + union acpi_object *out_obj; + int result, ret = -EINVAL; + struct pci_dev *bdev; + + if (!dev || PCI_FUNC(dev->devfn) != 0) + return -EINVAL; + + bdev = pci_acpi_check_dsm(dev, 4, 1 << DSM_PCI_D3COLD_AUX_POWER_LIMIT); + + if (IS_ERR(bdev)) + return PTR_ERR(bdev); + + out_obj = acpi_evaluate_dsm_typed(ACPI_HANDLE(&bdev->dev), + &pci_acpi_dsm_guid, 4, + DSM_PCI_D3COLD_AUX_POWER_LIMIT, + &in_obj, ACPI_TYPE_INTEGER); + if (!out_obj) + return -EINVAL; + + result = out_obj->integer.value; + if (retry_interval) + *retry_interval = 0; + + switch (result) { + case AUX_PWR_REQ_DENIED: + pci_dbg(bdev, "D3cold Aux Power %u mW request denied\n", + requested_mw); + break; + case AUX_PWR_REQ_GRANTED: + pci_info(bdev, "D3cold Aux Power request granted: %u mW\n", + requested_mw); + ret = 0; + break; + case AUX_PWR_REQ_NO_MAIN_PWR_REMOVAL: + pci_info(bdev, "D3cold Aux Power: Main power won't be removed\n"); + ret = -EBUSY; + break; + default: + if (result >= AUX_PWR_REQ_RETRY_INTERVAL_MIN && + result <= AUX_PWR_REQ_RETRY_INTERVAL_MAX) { + pci_info(bdev, "D3cold Aux Power request needs retry interval: %u seconds\n", + result & 0xF); + if (retry_interval) { + *retry_interval = result & 0xF; + ret = -EAGAIN; + } + } else { + pci_err(bdev, "D3cold Aux Power: Reserved or unsupported response: 0x%x\n", + result); + } + break; + } + + ACPI_FREE(out_obj); + return ret; +} +EXPORT_SYMBOL_GPL(pci_acpi_request_d3cold_aux_power); + static void pci_acpi_set_external_facing(struct pci_dev *dev) { u8 val; diff --git a/include/linux/pci-acpi.h b/include/linux/pci-acpi.h index 078225b514d4..ba48e7ddb360 100644 --- a/include/linux/pci-acpi.h +++ b/include/linux/pci-acpi.h @@ -121,6 +121,7 @@ extern const guid_t pci_acpi_dsm_guid; #define DSM_PCI_DEVICE_NAME 0x07 #define DSM_PCI_POWER_ON_RESET_DELAY 0x08 #define DSM_PCI_DEVICE_READINESS_DURATIONS 0x09 +#define DSM_PCI_D3COLD_AUX_POWER_LIMIT 0x0A #ifdef CONFIG_PCIE_EDR void pci_acpi_add_edr_notifier(struct pci_dev *pdev); @@ -132,10 +133,18 @@ static inline void pci_acpi_remove_edr_notifier(struct pci_dev *pdev) { } int pci_acpi_set_companion_lookup_hook(struct acpi_device *(*func)(struct pci_dev *)); void pci_acpi_clear_companion_lookup_hook(void); +int pci_acpi_request_d3cold_aux_power(struct pci_dev *dev, u32 requested_mw, + u32 *retry_interval); #else /* CONFIG_ACPI */ static inline void acpi_pci_add_bus(struct pci_bus *bus) { } static inline void acpi_pci_remove_bus(struct pci_bus *bus) { } +static inline int pci_acpi_request_d3cold_aux_power(struct pci_dev *dev, + u32 requested_mw, + u32 *retry_interval) +{ + return -EOPNOTSUPP; +} #endif /* CONFIG_ACPI */ #endif /* _PCI_ACPI_H_ */ -- 2.34.1