From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751426AbbI2Ea5 (ORCPT ); Tue, 29 Sep 2015 00:30:57 -0400 Received: from mail-wi0-f170.google.com ([209.85.212.170]:36630 "EHLO mail-wi0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750993AbbI2Eaz (ORCPT ); Tue, 29 Sep 2015 00:30:55 -0400 Subject: Re: [PATCH v3 1/7] acpi: Add early device probing infrastructure To: Marc Zyngier , "Rafael J. Wysocki" , Len Brown , Hanjun Guo , Tomasz Nowicki , Thomas Gleixner , Jason Cooper , Lorenzo Pieralisi , Sudeep Holla , Will Deacon , Catalin Marinas References: <1443451758-22717-1-git-send-email-marc.zyngier@arm.com> <1443451758-22717-2-git-send-email-marc.zyngier@arm.com> Cc: linaro-acpi@lists.linaro.org, linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org From: Daniel Lezcano Message-ID: <560A13FC.4080204@linaro.org> Date: Tue, 29 Sep 2015 06:30:52 +0200 User-Agent: Mozilla/5.0 (X11; Linux i686; rv:38.0) Gecko/20100101 Thunderbird/38.2.0 MIME-Version: 1.0 In-Reply-To: <1443451758-22717-2-git-send-email-marc.zyngier@arm.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Marc, On 09/28/2015 04:49 PM, Marc Zyngier wrote: > 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 | 66 +++++++++++++++++++++++++++++++++++++++ > 3 files changed, 115 insertions(+) > > diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c > index f834b8c..daf9fc8 100644 > --- a/drivers/acpi/scan.c > +++ b/drivers/acpi/scan.c > @@ -1913,3 +1913,42 @@ 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->subtable_valid || ape->subtable_valid(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); Isn't supposed 'acpi_table_parse_madt' to return the count ? and shouldn't the return code be checked ? > + 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; > +} -- Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog