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 0980B248893; Wed, 15 Oct 2025 08:02:37 +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=1760515358; cv=none; b=TNhFBE/++QvGYc17lRlRFY+gSQvdheW4NJGO5U3/vmkLxaIGNOHG6Iw/glRFsZBMybJQrFU8fwn0PEFndvHDVpEUBZxGztcB1vawy+aq61Iuzxsv/HLJB6XZvOnP3Pgw7Y8S6FhfsAlrWg2+fQLE7DiuvoGmRtQJDC6c7ZQSZ0c= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760515358; c=relaxed/simple; bh=dNRxtWySpLibrKPkWySj76he1Hl9+a7V5AisItSqoz4=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=aD30h5bL65iQKMtPiKQfccwhXi4MOE+jY6PCrn7cGR3lBnllUCjJQDgLPQHglvY0Y8aI/FOWiu6k+bMeKXeM+J+v/8abdll4lhyRObui1MGosRDmY/Sp/LBslvVYFgYMmMkoH882qpizxEw5to1bNnUcDY/Q6P1RTqiGjvWWfcg= 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=T58WFd29; 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="T58WFd29" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1760515357; x=1792051357; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=dNRxtWySpLibrKPkWySj76he1Hl9+a7V5AisItSqoz4=; b=T58WFd29rsEaDHBATyuQLhA6/o5ai9y5tV+UiuZ9gPWEFLkXpPrWUX5k mJguqhNgQr5CxCdbg2gFyEkno18Hv38YOhPYTCQfs/Fxl95cIb6kYUeVd F/g1qu1VHuYm/L+NTvTef4NmzqrNOHvV20ZXlBmtajr1d3G7qyiiDt2XD XtnRz30GP67Y1HyE2q/wAqKxqXdGC4srHtAbTs9fKiPYpUzNt0LD/O/vN oV0uwV2BQvyzRRDVkKawdcedtzcKycBjW2Ksk6WP78n/gxCdZThySVyWh MYluJZ4j14tqOz8i1uBYaLGfwXx/PEBncOLL/7FK0q4xsdR8AaU3qVLkc g==; X-CSE-ConnectionGUID: tIfvfMUpTLqLmyMTl2cgnw== X-CSE-MsgGUID: oFjVhbdnQtO0q5iRuQsqIQ== X-IronPort-AV: E=McAfee;i="6800,10657,11582"; a="61891462" X-IronPort-AV: E=Sophos;i="6.19,230,1754982000"; d="scan'208";a="61891462" 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 01:02:37 -0700 X-CSE-ConnectionGUID: snpCK1oBQzuhTxSjR+Vc9w== X-CSE-MsgGUID: sgH4KkcaRbeWQSOK+r/+kA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.19,230,1754982000"; d="scan'208";a="205805373" 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 01:02:33 -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 03/12] PCI/ACPI: Add PERST# Assertion Delay _DSM method Date: Wed, 15 Oct 2025 13:37:01 +0530 Message-Id: <20251015080710.1468409-4-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-pci@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Anshuman Gupta Implement _DSM Method 0Bh as per PCI Firmware r3.3, sec 4.6.10. Co-developed-by: Badal Nilawar Signed-off-by: Badal Nilawar Signed-off-by: Anshuman Gupta --- V2: - Call acpi_check_dsm() to find method 0Bh supported V3(Kappuswamy/Rafael): - %s/pci_warn/pci_info/ when PERST# Assertion Delay request fails --- drivers/pci/pci-acpi.c | 53 ++++++++++++++++++++++++++++++++++++++++ include/linux/pci-acpi.h | 9 ++++++- 2 files changed, 61 insertions(+), 1 deletion(-) diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c index 74f118016b1d..230077200ce8 100644 --- a/drivers/pci/pci-acpi.c +++ b/drivers/pci/pci-acpi.c @@ -1554,6 +1554,59 @@ int pci_acpi_request_d3cold_aux_power(struct pci_dev *dev, u32 requested_mw, } EXPORT_SYMBOL_GPL(pci_acpi_request_d3cold_aux_power); +/** + * pci_acpi_add_perst_assertion_delay - Request PERST# Delay via ACPI DSM + * @dev: PCI device instance + * @delay_us: Requested delay_us + * + * Request PERST# Assertion Delay to platform firmware, via Root Port/ + * Switch Downstream Port ACPI _DSM Function 0Bh, for the specified + * PCI device. + * Evaluate the _DSM and handle the response accordingly. + * + * Return: returns 0 on success and errno on failure. + */ +int pci_acpi_add_perst_assertion_delay(struct pci_dev *dev, u32 delay_us) +{ + union acpi_object in_obj = { + .integer.type = ACPI_TYPE_INTEGER, + .integer.value = delay_us, + }; + + union acpi_object *out_obj; + int result, ret = -EINVAL; + struct pci_dev *bdev; + + if (!dev) + return -EINVAL; + + bdev = pci_acpi_check_dsm(dev, 4, 1 << DSM_PCI_PERST_ASSERTION_DELAY); + + 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_PERST_ASSERTION_DELAY, + &in_obj, ACPI_TYPE_INTEGER); + if (!out_obj) + return -EINVAL; + + result = out_obj->integer.value; + + if (result == delay_us) { + pci_info(dev, "PERST# Assertion Delay set to %u microseconds\n", delay_us); + ret = 0; + } else { + pci_info(dev, "PERST# Assertion Delay request failed, using %u microseconds\n", + result); + } + + ACPI_FREE(out_obj); + return ret; +} +EXPORT_SYMBOL_GPL(pci_acpi_add_perst_assertion_delay); + 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 ba48e7ddb360..4d8b8cea019e 100644 --- a/include/linux/pci-acpi.h +++ b/include/linux/pci-acpi.h @@ -122,6 +122,7 @@ extern const guid_t pci_acpi_dsm_guid; #define DSM_PCI_POWER_ON_RESET_DELAY 0x08 #define DSM_PCI_DEVICE_READINESS_DURATIONS 0x09 #define DSM_PCI_D3COLD_AUX_POWER_LIMIT 0x0A +#define DSM_PCI_PERST_ASSERTION_DELAY 0x0B #ifdef CONFIG_PCIE_EDR void pci_acpi_add_edr_notifier(struct pci_dev *pdev); @@ -135,7 +136,7 @@ int pci_acpi_set_companion_lookup_hook(struct acpi_device *(*func)(struct pci_de 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); - +int pci_acpi_add_perst_assertion_delay(struct pci_dev *dev, u32 delay_us); #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) { } @@ -145,6 +146,12 @@ static inline int pci_acpi_request_d3cold_aux_power(struct pci_dev *dev, { return -EOPNOTSUPP; } + +static inline int pci_acpi_add_perst_assertion_delay(struct pci_dev *dev, + u32 delay_us) +{ + return -EOPNOTSUPP; +} #endif /* CONFIG_ACPI */ #endif /* _PCI_ACPI_H_ */ -- 2.34.1