From nobody Tue Feb 10 19:00:52 2026 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 2EFD715CD6D; Thu, 18 Apr 2024 12:13:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713442403; cv=none; b=DjLKcdbXYsnXO5gFfMr4SNoD5MEDLEZQnMit69ehylzxq3nuyGmlp2joVfmrFJDs/vDFqScE3sOVSP33EmT6KYcByyj4CHBO+Xe5x2DKObJcxFvtY3x5Iba5QCjKU2j3TsK78PKynTo17YMV+cuPGs5rx0OsNv7i+EPBSLcqo0U= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713442403; c=relaxed/simple; bh=t/3x9YvwBgeGmtfyzNrlEkhf5PPJrI/KNYc7npUqxro=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=c/a/0b6dlTrSUHbCSRiQCFg6YvBCtWBBnZnvySTDDmlrzpPKyet5Sk67WYWdWRBz4E+LTPQ7P4+T1sUbGaask2qW+pyqvjKEKqKLbzLsmhsERvjk1hkpPEPFWK2e5sdUGtB6XI0fnflFu8P+lxFve1A++emYTNHX+iYmXmWKJhk= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=zx2c4.com header.i=@zx2c4.com header.b=JXgOeqo1; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=zx2c4.com header.i=@zx2c4.com header.b="JXgOeqo1" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EDC7BC2BD11; Thu, 18 Apr 2024 12:13:21 +0000 (UTC) Authentication-Results: smtp.kernel.org; dkim=pass (1024-bit key) header.d=zx2c4.com header.i=@zx2c4.com header.b="JXgOeqo1" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zx2c4.com; s=20210105; t=1713442400; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=WYdtdVBdKQeCcimrRJ83g62GTKmsxlDxFsEgHkC3E4w=; b=JXgOeqo1SOQWKX4vu30f/hU75KMK1tYGpPcJqrF7XwKKIhJ3UcW+WbskoOS3A2u6/xjmZW I8BVN9q72bEbghS5GsjHBUKNfTqrBYf48P22KL2tNSgUkrCtMoOpvQVyCvf4EJoPOTkuSb XWU4R3E2qcMuq3pH5N7v9ebMvWfiFGA= Received: by mail.zx2c4.com (ZX2C4 Mail Server) with ESMTPSA id 0f0ba801 (TLSv1.3:TLS_AES_256_GCM_SHA384:256:NO); Thu, 18 Apr 2024 12:13:19 +0000 (UTC) From: "Jason A. Donenfeld" To: tytso@mit.edu, robh@kernel.org, krzk@kernel.org, conor+dt@kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, sudanl@amazon.com, graf@amazon.com, dwmw@amazon.co.uk, krzysztof.kozlowski@linaro.org Cc: "Jason A . Donenfeld" Subject: [PATCH v7 1/3] virt: vmgenid: change implementation to use a platform driver Date: Thu, 18 Apr 2024 14:12:30 +0200 Message-ID: <20240418121249.42380-2-Jason@zx2c4.com> In-Reply-To: <20240418121249.42380-1-Jason@zx2c4.com> References: <20240418121249.42380-1-Jason@zx2c4.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Sudan Landge Re-implement vmgenid as a platform driver in preparation for adding devicetree bindings support in next commits. Signed-off-by: Sudan Landge Reviewed-by: Alexander Graf [Jason: - Small style cleanups and refactoring.] Signed-off-by: Jason A. Donenfeld --- drivers/virt/vmgenid.c | 99 +++++++++++++++++++++++++++--------------- 1 file changed, 65 insertions(+), 34 deletions(-) diff --git a/drivers/virt/vmgenid.c b/drivers/virt/vmgenid.c index a1c467a0e9f7..aebbd24512c9 100644 --- a/drivers/virt/vmgenid.c +++ b/drivers/virt/vmgenid.c @@ -7,9 +7,10 @@ * information to random.c. */ =20 +#include #include #include -#include +#include #include =20 ACPI_MODULE_NAME("vmgenid"); @@ -21,19 +22,41 @@ struct vmgenid_state { u8 this_id[VMGENID_SIZE]; }; =20 -static int vmgenid_add(struct acpi_device *device) +static void vmgenid_notify(struct device *device) +{ + struct vmgenid_state *state =3D device->driver_data; + u8 old_id[VMGENID_SIZE]; + + memcpy(old_id, state->this_id, sizeof(old_id)); + memcpy(state->this_id, state->next_id, sizeof(state->this_id)); + if (!memcmp(old_id, state->this_id, sizeof(old_id))) + return; + add_vmfork_randomness(state->this_id, sizeof(state->this_id)); +} + +static void setup_vmgenid_state(struct vmgenid_state *state, void *virt_ad= dr) { + state->next_id =3D virt_addr; + memcpy(state->this_id, state->next_id, sizeof(state->this_id)); + add_device_randomness(state->this_id, sizeof(state->this_id)); +} + +static void vmgenid_acpi_handler(acpi_handle __always_unused handle, + u32 __always_unused event, void *dev) +{ + vmgenid_notify(dev); +} + +static int vmgenid_add_acpi(struct device *dev, struct vmgenid_state *stat= e) +{ + struct acpi_device *device =3D ACPI_COMPANION(dev); struct acpi_buffer parsed =3D { ACPI_ALLOCATE_BUFFER }; - struct vmgenid_state *state; union acpi_object *obj; phys_addr_t phys_addr; acpi_status status; + void *virt_addr; int ret =3D 0; =20 - state =3D devm_kmalloc(&device->dev, sizeof(*state), GFP_KERNEL); - if (!state) - return -ENOMEM; - status =3D acpi_evaluate_object(device->handle, "ADDR", NULL, &parsed); if (ACPI_FAILURE(status)) { ACPI_EXCEPTION((AE_INFO, status, "Evaluating ADDR")); @@ -49,53 +72,61 @@ static int vmgenid_add(struct acpi_device *device) =20 phys_addr =3D (obj->package.elements[0].integer.value << 0) | (obj->package.elements[1].integer.value << 32); - state->next_id =3D devm_memremap(&device->dev, phys_addr, VMGENID_SIZE, M= EMREMAP_WB); - if (IS_ERR(state->next_id)) { - ret =3D PTR_ERR(state->next_id); + + virt_addr =3D devm_memremap(&device->dev, phys_addr, VMGENID_SIZE, MEMREM= AP_WB); + if (IS_ERR(virt_addr)) { + ret =3D PTR_ERR(virt_addr); goto out; } + setup_vmgenid_state(state, virt_addr); =20 - memcpy(state->this_id, state->next_id, sizeof(state->this_id)); - add_device_randomness(state->this_id, sizeof(state->this_id)); - - device->driver_data =3D state; + status =3D acpi_install_notify_handler(device->handle, ACPI_DEVICE_NOTIFY, + vmgenid_acpi_handler, dev); + if (ACPI_FAILURE(status)) { + ret =3D -ENODEV; + goto out; + } =20 + dev->driver_data =3D state; out: ACPI_FREE(parsed.pointer); return ret; } =20 -static void vmgenid_notify(struct acpi_device *device, u32 event) +static int vmgenid_add(struct platform_device *pdev) { - struct vmgenid_state *state =3D acpi_driver_data(device); - u8 old_id[VMGENID_SIZE]; + struct vmgenid_state *state; + struct device *dev =3D &pdev->dev; + int ret =3D 0; =20 - memcpy(old_id, state->this_id, sizeof(old_id)); - memcpy(state->this_id, state->next_id, sizeof(state->this_id)); - if (!memcmp(old_id, state->this_id, sizeof(old_id))) - return; - add_vmfork_randomness(state->this_id, sizeof(state->this_id)); + state =3D devm_kmalloc(dev, sizeof(*state), GFP_KERNEL); + if (!state) + return -ENOMEM; + + ret =3D vmgenid_add_acpi(dev, state); + + if (ret) + devm_kfree(dev, state); + return ret; } =20 -static const struct acpi_device_id vmgenid_ids[] =3D { +static const struct acpi_device_id vmgenid_acpi_ids[] =3D { { "VMGENCTR", 0 }, { "VM_GEN_COUNTER", 0 }, { } }; - -static struct acpi_driver vmgenid_driver =3D { - .name =3D "vmgenid", - .ids =3D vmgenid_ids, - .owner =3D THIS_MODULE, - .ops =3D { - .add =3D vmgenid_add, - .notify =3D vmgenid_notify - } +MODULE_DEVICE_TABLE(acpi, vmgenid_acpi_ids); + +static struct platform_driver vmgenid_plaform_driver =3D { + .probe =3D vmgenid_add, + .driver =3D { + .name =3D "vmgenid", + .acpi_match_table =3D vmgenid_acpi_ids, + }, }; =20 -module_acpi_driver(vmgenid_driver); +module_platform_driver(vmgenid_plaform_driver) =20 -MODULE_DEVICE_TABLE(acpi, vmgenid_ids); MODULE_DESCRIPTION("Virtual Machine Generation ID"); MODULE_LICENSE("GPL v2"); MODULE_AUTHOR("Jason A. Donenfeld "); --=20 2.44.0