From patchwork Tue Jun 2 15:24:56 2009 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexander Chiang X-Patchwork-Id: 27503 Received: from vger.kernel.org (vger.kernel.org [209.132.176.167]) by demeter.kernel.org (8.14.2/8.14.2) with ESMTP id n52FQBnB013116 for ; Tue, 2 Jun 2009 15:26:12 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757851AbZFBPY4 (ORCPT ); Tue, 2 Jun 2009 11:24:56 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757374AbZFBPY4 (ORCPT ); Tue, 2 Jun 2009 11:24:56 -0400 Received: from g4t0015.houston.hp.com ([15.201.24.18]:47268 "EHLO g4t0015.houston.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757803AbZFBPYy (ORCPT ); Tue, 2 Jun 2009 11:24:54 -0400 Received: from smtp2.fc.hp.com (smtp.cnd.hp.com [15.11.136.114]) by g4t0015.houston.hp.com (Postfix) with ESMTP id BBE27814F; Tue, 2 Jun 2009 15:24:56 +0000 (UTC) Received: from localhost.localdomain (lart.fc.hp.com [15.11.146.31]) by smtp2.fc.hp.com (Postfix) with ESMTP id 3243F2CB707; Tue, 2 Jun 2009 14:56:20 +0000 (UTC) Received: from bob.kio (localhost [127.0.0.1]) by localhost.localdomain (Postfix) with ESMTP id 80BFF26142; Tue, 2 Jun 2009 09:24:56 -0600 (MDT) Subject: [PATCH 04/10] ACPI: Introduce acpi_get_pci_dev() To: lenb@kernel.org From: Alex Chiang Cc: linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org Date: Tue, 02 Jun 2009 09:24:56 -0600 Message-ID: <20090602152456.7346.64853.stgit@bob.kio> In-Reply-To: <20090602152351.7346.48697.stgit@bob.kio> References: <20090602152351.7346.48697.stgit@bob.kio> User-Agent: StGit/0.14.3.347.g594a MIME-Version: 1.0 Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Convert an ACPI CA handle to a struct pci_dev. Performing this lookup dynamically allows us to get rid of the ACPI-PCI binding code, which: - eliminates struct acpi_device vs struct pci_dev lifetime issues - lays more groundwork for eliminating .start from acpi_device_ops and thus simplifying ACPI drivers - whacks out a lot of code This change also changes the time-space tradeoff ever so slightly. Looking up the ACPI-PCI binding is never in the performance path, and by eliminating this caching, we save 24 bytes for each _ADR device in the ACPI namespace. Signed-off-by: Alex Chiang --- drivers/acpi/pci_bind.c | 83 +++++++++++++++++++++++++++++++++++++++++++ include/acpi/acpi_drivers.h | 1 + 2 files changed, 84 insertions(+), 0 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff --git a/drivers/acpi/pci_bind.c b/drivers/acpi/pci_bind.c index 236765c..584fa30 100644 --- a/drivers/acpi/pci_bind.c +++ b/drivers/acpi/pci_bind.c @@ -56,6 +56,89 @@ static void acpi_pci_data_handler(acpi_handle handle, u32 function, return; } +struct acpi_handle_node { + struct list_head node; + acpi_handle handle; +}; + +/** + * acpi_get_pci_dev - convert ACPI CA handle to struct pci_dev + * @handle: the handle in question + * + * Given an ACPI CA handle, the desired PCI device is located in the + * list of PCI devices. + * + * If the device is found, its reference count is increased and this + * function returns a pointer to its data structure. The caller must + * decrement the reference count by calling pci_dev_put(). + * If no device is found, %NULL is returned. + */ +struct pci_dev *acpi_get_pci_dev(acpi_handle handle) +{ + int dev, fn; + unsigned long long adr; + acpi_status status; + acpi_handle phandle; + struct pci_bus *pbus; + struct pci_dev *pdev = NULL; + struct acpi_handle_node *node, *tmp; + struct acpi_pci_root *root; + LIST_HEAD(device_list); + + /* + * Walk up the ACPI CA namespace until we reach a PCI root bridge. + */ + phandle = handle; + while (!acpi_is_root_bridge(phandle)) { + node = kzalloc(sizeof(struct acpi_handle_node), GFP_KERNEL); + if (!node) + goto out; + + INIT_LIST_HEAD(&node->node); + node->handle = phandle; + list_add(&node->node, &device_list); + + status = acpi_get_parent(phandle, &phandle); + if (ACPI_FAILURE(status)) + goto out; + } + + root = acpi_pci_find_root(phandle); + if (!root) + goto out; + + pbus = pci_find_bus(root->id.segment, root->id.bus); + if (!pbus) + goto out; + + /* + * Now, walk back down the PCI device tree until we return to our + * original handle. Assumes that everything between the PCI root + * bridge and the device we're looking for must be a P2P bridge. + */ + list_for_each_entry_safe(node, tmp, &device_list, node) { + acpi_handle hnd = node->handle; + status = acpi_evaluate_integer(hnd, "_ADR", NULL, &adr); + if (ACPI_FAILURE(status)) + goto out; + dev = (adr >> 16) & 0xffff; + fn = adr & 0xffff; + + list_del(&node->node); + kfree(node); + + pdev = pci_get_slot(pbus, PCI_DEVFN(dev, fn)); + if (hnd == handle) + break; + + pbus = pdev->subordinate; + pci_dev_put(pdev); + } +out: + return pdev; +} +EXPORT_SYMBOL_GPL(acpi_get_pci_dev); + /** * acpi_get_pci_id * ------------------ diff --git a/include/acpi/acpi_drivers.h b/include/acpi/acpi_drivers.h index bbe9207..1ef529b 100644 --- a/include/acpi/acpi_drivers.h +++ b/include/acpi/acpi_drivers.h @@ -97,6 +97,7 @@ void acpi_pci_irq_del_prt(int segment, int bus); struct pci_bus; +struct pci_dev *acpi_get_pci_dev(acpi_handle); acpi_status acpi_get_pci_id(acpi_handle handle, struct acpi_pci_id *id); int acpi_pci_bind_root(struct acpi_device *device, struct acpi_pci_id *id, struct pci_bus *bus);