From patchwork Sun Sep 13 14:02:19 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marc Zyngier X-Patchwork-Id: 7169301 Return-Path: X-Original-To: patchwork-linux-acpi@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id D84A39F326 for ; Sun, 13 Sep 2015 14:03:40 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id D5F8020603 for ; Sun, 13 Sep 2015 14:03:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0AC21206A5 for ; Sun, 13 Sep 2015 14:03:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753023AbbIMODJ (ORCPT ); Sun, 13 Sep 2015 10:03:09 -0400 Received: from foss.arm.com ([217.140.101.70]:42985 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752486AbbIMOC6 (ORCPT ); Sun, 13 Sep 2015 10:02:58 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 6899F483; Sun, 13 Sep 2015 07:03:11 -0700 (PDT) Received: from zomby-woof.lan (usa-sjc-mx-foss1.foss.arm.com [217.140.101.70]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id F3DED3F57E; Sun, 13 Sep 2015 07:02:54 -0700 (PDT) From: Marc Zyngier To: "Rafael J. Wysocki" , Len Brown , Hanjun Guo , Tomasz Nowicki , Thomas Gleixner , Jason Cooper , Lorenzo Pieralisi , Sudeep Holla , Will Deacon , Catalin Marinas Cc: linaro-acpi@lists.linaro.org, linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: [PATCH v2 1/5] acpi: Add basic device probing infrastructure Date: Sun, 13 Sep 2015 15:02:19 +0100 Message-Id: <1442152943-24493-2-git-send-email-marc.zyngier@arm.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1442152943-24493-1-git-send-email-marc.zyngier@arm.com> References: <1442152943-24493-1-git-send-email-marc.zyngier@arm.com> Sender: linux-acpi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP IRQ controllers and timers are the two types of device the kernel requires before being able to use the device driver model. ACPI so far lacks a proper probing infrastructure similar to the one we have with DT, where we're able to declare IRQ chips and clocksources inside the driver code, and let the core code pick it up and call us back on a match. This leads to all kind of really ugly hacks all over the arm64 code and even in the ACPI layer. In order to allow some basic probing based on the ACPI tables, introduce "struct acpi_probe_entry" which contains just enough data and callbacks to match a table, an optional subtable, and call a probe function. A driver can, at build time, register itself and expect being called if the right entry exists in the ACPI table. A acpi_probe_device_table() is provided, taking an identifier for a set of acpi_prove_entries, and iterating over the registered entries. Signed-off-by: Marc Zyngier --- drivers/acpi/scan.c | 39 +++++++++++++++++++++++ include/asm-generic/vmlinux.lds.h | 10 ++++++ include/linux/acpi.h | 65 +++++++++++++++++++++++++++++++++++++++ 3 files changed, 114 insertions(+) diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index 01136b8..ac3030b 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -1933,3 +1933,42 @@ int __init acpi_scan_init(void) mutex_unlock(&acpi_scan_lock); return result; } + +static struct acpi_probe_entry *ape; +static int acpi_probe_count; +static DEFINE_SPINLOCK(acpi_probe_lock); + +static int __init acpi_match_madt(struct acpi_subtable_header *header, + const unsigned long end) +{ + if (!ape->validate_subtbl || ape->validate_subtbl(header, ape)) + if (!ape->probe_subtbl(header, end)) + acpi_probe_count++; + + return 0; +} + +int __init __acpi_probe_device_table(struct acpi_probe_entry *ap_head, int nr) +{ + int count = 0; + + if (acpi_disabled) + return 0; + + spin_lock(&acpi_probe_lock); + for (ape = ap_head; nr; ape++, nr--) { + if (ACPI_COMPARE_NAME(ACPI_SIG_MADT, ape->id)) { + acpi_probe_count = 0; + acpi_table_parse_madt(ape->type, acpi_match_madt, 0); + count += acpi_probe_count; + } else { + int res; + res = acpi_table_parse(ape->id, ape->probe_table); + if (!res) + count++; + } + } + spin_unlock(&acpi_probe_lock); + + return count; +} diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index 1781e54..efd7ed1 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -181,6 +181,16 @@ #define CPUIDLE_METHOD_OF_TABLES() OF_TABLE(CONFIG_CPU_IDLE, cpuidle_method) #define EARLYCON_OF_TABLES() OF_TABLE(CONFIG_SERIAL_EARLYCON, earlycon) +#ifdef CONFIG_ACPI +#define ACPI_PROBE_TABLE(name) \ + . = ALIGN(8); \ + VMLINUX_SYMBOL(__##name##_acpi_probe_table) = .; \ + *(__##name##_acpi_probe_table) \ + VMLINUX_SYMBOL(__##name##_acpi_probe_table_end) = .; +#else +#define ACPI_PROBE_TABLE(name) +#endif + #define KERNEL_DTB() \ STRUCT_ALIGN(); \ VMLINUX_SYMBOL(__dtb_start) = .; \ diff --git a/include/linux/acpi.h b/include/linux/acpi.h index 7235c48..c63fbda 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h @@ -759,6 +759,61 @@ int acpi_dev_prop_read(struct acpi_device *adev, const char *propname, struct acpi_device *acpi_get_next_child(struct device *dev, struct acpi_device *child); + +struct acpi_probe_entry; +typedef bool (*acpi_probe_entry_validate_subtbl)(struct acpi_subtable_header *, + struct acpi_probe_entry *); + +#define ACPI_TABLE_ID_LEN 5 + +/** + * struct acpi_probe_entry - boot-time probing entry + * @id: ACPI table name + * @type: Optional subtable type to match + * (if @id contains subtables) + * @validate_subtbl: Optional callback to check the validity of + * the subtable + * @probe_table: Callback to the driver being probed when table + * match is successful + * @probe_subtbl: Callback to the driver being probed when table and + * subtable match (and optionnal callback is successful) + * @driver_data: Sideband data provided back to the driver + */ +struct acpi_probe_entry { + __u8 id[ACPI_TABLE_ID_LEN]; + __u8 type; + acpi_probe_entry_validate_subtbl validate_subtbl; + union { + acpi_tbl_table_handler probe_table; + acpi_tbl_entry_handler probe_subtbl; + }; + kernel_ulong_t driver_data; +}; + +#define ACPI_DECLARE(table, name, table_id, subtable, valid, data, fn) \ + static const struct acpi_probe_entry __acpi_probe_##name \ + __used __section(__##table##_acpi_probe_table) \ + = { \ + .id = table_id, \ + .type = subtable, \ + .validate_subtbl = valid, \ + .probe_table = (acpi_tbl_table_handler)fn, \ + .driver_data = data, \ + } + +#define ACPI_PROBE_TABLE(name) __##name##_acpi_probe_table +#define ACPI_PROBE_TABLE_END(name) __##name##_acpi_probe_table_end + +int __acpi_probe_device_table(struct acpi_probe_entry *start, int nr); + +#define acpi_probe_device_table(t) \ + ({ \ + extern struct acpi_probe_entry ACPI_PROBE_TABLE(t), \ + ACPI_PROBE_TABLE_END(t); \ + __acpi_probe_device_table(&ACPI_PROBE_TABLE(t), \ + (&ACPI_PROBE_TABLE_END(t) - \ + &ACPI_PROBE_TABLE(t))); \ + }) #else static inline int acpi_dev_get_property(struct acpi_device *adev, const char *name, acpi_object_type type, @@ -809,6 +864,16 @@ static inline struct acpi_device *acpi_get_next_child(struct device *dev, return NULL; } +#define ACPI_DECLARE(table, name, table_id, subtable, validate, data, fn) \ + static const void * __acpi_table_##name[] \ + __attribute__((unused)) \ + = { (void *) table_id, \ + (void *) subtable, \ + (void *) valid, \ + (void *) fn, \ + (void *) data } + +#define acpi_probe_device_table(t) ({ int __r = 0; __r;}) #endif #endif /*_LINUX_ACPI_H*/