From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj1-f73.google.com (mail-pj1-f73.google.com [209.85.216.73]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 09747382F35 for ; Fri, 22 May 2026 20:24:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.73 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779481463; cv=none; b=AuG0x0MyLGhcWRl7e/92TjzyjhCSF083sWcDpr781znfbWRK2qtgJDdflnwY3N3TNH8JGkp5lv2kHR9W9bi1TTXrXiwKrq2ww2liVTrz8k2ikUVV39q9dnziAf0a6eleCWMm8EFD46irL3pyxOJt8BkbsVbdSHs4xWFsKhDqWNg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779481463; c=relaxed/simple; bh=vt29mpxfdN0oynKpwfSKNPgSGC8PTO+Nd0Edazw1zxI=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=ieh6OoW4ubrUewsiEeU/vciKMzgTU+supIX78/Ky+6ju+tuG+2fbELoXrNhIrIsDaz6CVnsjNfyt1S9VC25vTV6vLCUnQNjTc06wOHHRVFdvDevWHOyVzE6HKLyP7uwKu+xFZZl5qWbVzpucVdXYIYxJfDtNKe/ucE4KL04gcW0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--dmatlack.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=hW6XQh/Y; arc=none smtp.client-ip=209.85.216.73 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--dmatlack.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="hW6XQh/Y" Received: by mail-pj1-f73.google.com with SMTP id 98e67ed59e1d1-366ded5ab5fso15309087a91.0 for ; Fri, 22 May 2026 13:24:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1779481461; x=1780086261; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=n5gRktteoUb/1GJUOFc5t/RbM6I0eXe+lj3sebUBczU=; b=hW6XQh/YG3z/1o2uZJGwCH/Z3VVLev90bLEAbA3VuUe5tWjA0xmyf0PBoXOlWM6r9h bifsIEFxC9Ry8WNTQ+ZtiiORIOJ97Odhyn04SkUXTneUN20dedMheytQv4iQ4YbPTTdg tqDg6uiSA+e731mBDXfA72CxP3SsuHfQzIhGkE5povIPRGbTuK9h38X+/7t9RlOmi3tE zKX/nszskEKWT3Np7TLzyUjVpc8vz7nW5xrm+WBcVV2HlQIeMPfVBOGHhGTvdqjBDwoP zzXaJjhdSzUz25w8IE5zxZ+lg1dyLsiwAYUFxs95WF7rYIldLRt2FYzLD683MJ6n/HXb zg4g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1779481461; x=1780086261; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=n5gRktteoUb/1GJUOFc5t/RbM6I0eXe+lj3sebUBczU=; b=j4TmvGH5TbZ3mhY3TnmtbsnBcS9tRVKLXoRN6P4zpVd2W1DUY2Kq67oWW5RTJ3VQmw rVI6yR7fuB/RFpBYUasONU4/NAKHLx0oSzit26Ncyw6C+TjTkNsPMTHtRM/QP4gF0B7V MOUOkIr2AK58CvoAP2AxL7iYlKsqeJvQpyVHuAbN2ThzAcmwU3uLibiH+xf3JxE5njPV /KKhovYfVs6apRKhyoKglnQgtk6hYpLmWUDGxFHd45lFmIbC1F72F8yvM+a+R+2nGOMd St372M0Vs9nPHgC7/Y7HAfoxudzlsBbb9K9bLwdh6dneLTj9clFDrxV1YMN/HPTu+vOm arkQ== X-Forwarded-Encrypted: i=1; AFNElJ8UdNeFESqJy0xeDm/VRH/L1f10DxHWWAJ5iR2fleP+MTTPbyTWZc3aJDVfRfE3lLfRVIJPtuldxCQ=@vger.kernel.org X-Gm-Message-State: AOJu0YxFVcwUEuPaKosznvxq5gjaukzwP3zl9JCjxaywuyeUNJjrnb8S kWEjGgGnXkjq9j06tQzLJ0pBl+dvJGnx4R2HZ2bvqSEm3Gydf5FHZO8GmpDLeuXMFTdlefQmIlo g1oYTzJVA9BUosQ== X-Received: from pjbtc4.prod.google.com ([2002:a17:90b:5404:b0:36a:81c9:4523]) (user=dmatlack job=prod-delivery.src-stubby-dispatcher) by 2002:a17:90b:3ecc:b0:369:d7c6:450a with SMTP id 98e67ed59e1d1-36a671e974emr5405438a91.0.1779481460825; Fri, 22 May 2026 13:24:20 -0700 (PDT) Date: Fri, 22 May 2026 20:24:08 +0000 In-Reply-To: <20260522202410.3104264-1-dmatlack@google.com> Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260522202410.3104264-1-dmatlack@google.com> X-Mailer: git-send-email 2.54.0.746.g67dd491aae-goog Message-ID: <20260522202410.3104264-11-dmatlack@google.com> Subject: [PATCH v6 10/12] PCI: liveupdate: Freeze preservation status during shutdown From: David Matlack To: kexec@lists.infradead.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-pci@vger.kernel.org Cc: Adithya Jayachandran , Alexander Graf , Alex Williamson , Bjorn Helgaas , Chris Li , David Matlack , David Rientjes , Jacob Pan , Jason Gunthorpe , Jonathan Corbet , Josh Hilke , Leon Romanovsky , Lukas Wunner , Mike Rapoport , Parav Pandit , Pasha Tatashin , Pranjal Shrivastava , Pratyush Yadav , Saeed Mahameed , Samiullah Khawaja , Shuah Khan , Vipin Sharma , William Tu , Yi Liu Content-Type: text/plain; charset="UTF-8" Freeze a device's outgoing preservation status (preserved or not preserved) during shutdown. This enables the PCI core and drivers to safely make decisions based on the device's preservation status during shutdown. Note that pci_liveupdate_freeze() is triggered by the PCI core rather than from drivers participating in Live Update so that all devices can have their status frozen (i.e. prevent non-preserved devices from getting preserved late). Signed-off-by: David Matlack --- drivers/pci/liveupdate.c | 16 ++++++++++++++++ drivers/pci/liveupdate.h | 5 +++++ drivers/pci/pci-driver.c | 2 ++ include/linux/pci_liveupdate.h | 3 +++ 4 files changed, 26 insertions(+) diff --git a/drivers/pci/liveupdate.c b/drivers/pci/liveupdate.c index 701276ef6cfb..d404e64a4e55 100644 --- a/drivers/pci/liveupdate.c +++ b/drivers/pci/liveupdate.c @@ -297,6 +297,11 @@ static int pci_liveupdate_unpreserve_device(struct pci_ser *ser, struct pci_dev { struct pci_dev_ser *dev_ser = dev->liveupdate.outgoing; + if (dev->liveupdate.frozen) { + pci_warn(dev, "Cannot unpreserve device after it is frozen!\n"); + return -EINVAL; + } + if (!dev_ser) { pci_warn(dev, "Cannot unpreserve device that is not preserved\n"); return -EINVAL; @@ -380,6 +385,11 @@ static int __pci_liveupdate_preserve_device(struct pci_ser *ser, struct pci_dev static int pci_liveupdate_preserve_device(struct pci_ser *ser, struct pci_dev *dev) { + if (dev->liveupdate.frozen) { + pci_warn(dev, "Cannot preserve device after it is frozen!\n"); + return -EINVAL; + } + if (dev->liveupdate.outgoing) return pci_liveupdate_preserve_device_again(dev); @@ -653,6 +663,12 @@ void pci_liveupdate_cleanup_device(struct pci_dev *dev) } } +void pci_liveupdate_freeze(struct pci_dev *dev) +{ + guard(rwsem_write)(&pci_liveupdate.rwsem); + dev->liveupdate.frozen = 1; +} + static int pci_liveupdate_finish_device(struct pci_ser *ser, struct pci_dev *dev) { if (!dev->liveupdate.incoming) { diff --git a/drivers/pci/liveupdate.h b/drivers/pci/liveupdate.h index 6f21ec50927b..bcb0bc73d684 100644 --- a/drivers/pci/liveupdate.h +++ b/drivers/pci/liveupdate.h @@ -13,6 +13,7 @@ #ifdef CONFIG_PCI_LIVEUPDATE void pci_liveupdate_setup_device(struct pci_dev *dev); void pci_liveupdate_cleanup_device(struct pci_dev *dev); +void pci_liveupdate_freeze(struct pci_dev *dev); bool pci_liveupdate_scan_bridge_begin(struct pci_bus *bus, struct pci_dev *dev, int pass); void pci_liveupdate_scan_bridge_end(struct pci_dev *dev, int pass); @@ -28,6 +29,10 @@ static inline void pci_liveupdate_cleanup_device(struct pci_dev *dev) { } +static inline void pci_liveupdate_freeze(struct pci_dev *dev) +{ +} + static inline bool pci_liveupdate_scan_bridge_begin(struct pci_bus *bus, struct pci_dev *dev, int pass) diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c index d10ece0889f0..f7a5e65a7c75 100644 --- a/drivers/pci/pci-driver.c +++ b/drivers/pci/pci-driver.c @@ -21,6 +21,7 @@ #include #include #include +#include "liveupdate.h" #include "pci.h" #include "pcie/portdrv.h" @@ -536,6 +537,7 @@ static void pci_device_shutdown(struct device *dev) struct pci_dev *pci_dev = to_pci_dev(dev); struct pci_driver *drv = pci_dev->driver; + pci_liveupdate_freeze(pci_dev); pm_runtime_resume(dev); if (drv && drv->shutdown) diff --git a/include/linux/pci_liveupdate.h b/include/linux/pci_liveupdate.h index 2446c6d237ca..150993405754 100644 --- a/include/linux/pci_liveupdate.h +++ b/include/linux/pci_liveupdate.h @@ -24,6 +24,8 @@ * @was_preserved: True if this struct pci_dev was preserved by the previous * kernel. Unlike @incoming, this field is not cleared after * the device is finished participating in Live Update. + * @frozen: True if the outgoing preservation status of this device is frozen + * and thus cannot be changed. */ struct pci_liveupdate { struct pci_dev_ser *outgoing; @@ -31,6 +33,7 @@ struct pci_liveupdate { u16 acs_ctrl; bool inherit_buses; bool was_preserved; + bool frozen; }; struct pci_dev; -- 2.54.0.746.g67dd491aae-goog