From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751460AbdASJLw (ORCPT ); Thu, 19 Jan 2017 04:11:52 -0500 Received: from mail-pf0-f173.google.com ([209.85.192.173]:35106 "EHLO mail-pf0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751426AbdASJLq (ORCPT ); Thu, 19 Jan 2017 04:11:46 -0500 Subject: Re: [PATCH v20 13/17] acpi/arm64: Add GTDT table parse driver To: fu.wei@linaro.org, rjw@rjwysocki.net, lenb@kernel.org, daniel.lezcano@linaro.org, tglx@linutronix.de, marc.zyngier@arm.com, mark.rutland@arm.com, lorenzo.pieralisi@arm.com, sudeep.holla@arm.com References: <20170118132541.8989-1-fu.wei@linaro.org> <20170118132541.8989-14-fu.wei@linaro.org> Cc: linux-arm-kernel@lists.infradead.org, linaro-acpi@lists.linaro.org, linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org, rruigrok@codeaurora.org, harba@codeaurora.org, cov@codeaurora.org, timur@codeaurora.org, graeme.gregory@linaro.org, al.stone@linaro.org, jcm@redhat.com, wei@redhat.com, arnd@arndb.de, catalin.marinas@arm.com, will.deacon@arm.com, Suravee.Suthikulpanit@amd.com, leo.duran@amd.com, wim@iguana.be, linux@roeck-us.net, linux-watchdog@vger.kernel.org, tn@semihalf.com, christoffer.dall@linaro.org, julien.grall@arm.com From: Hanjun Guo Message-ID: Date: Thu, 19 Jan 2017 17:11:29 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.6.0 MIME-Version: 1.0 In-Reply-To: <20170118132541.8989-14-fu.wei@linaro.org> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2017/1/18 21:25, fu.wei@linaro.org wrote: > From: Fu Wei > > This patch adds support for parsing arch timer info in GTDT, > provides some kernel APIs to parse all the PPIs and > always-on info in GTDT and export them. > > By this driver, we can simplify arm_arch_timer drivers, and > separate the ACPI GTDT knowledge from it. > > Signed-off-by: Fu Wei > Signed-off-by: Hanjun Guo > Acked-by: Rafael J. Wysocki > Tested-by: Xiongfeng Wang > --- > arch/arm64/Kconfig | 1 + > drivers/acpi/arm64/Kconfig | 3 + > drivers/acpi/arm64/Makefile | 1 + > drivers/acpi/arm64/gtdt.c | 157 ++++++++++++++++++++++++++++++++++++++++++++ > include/linux/acpi.h | 6 ++ > 5 files changed, 168 insertions(+) > > diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig > index 1117421..ab1ee10 100644 > --- a/arch/arm64/Kconfig > +++ b/arch/arm64/Kconfig > @@ -2,6 +2,7 @@ config ARM64 > def_bool y > select ACPI_CCA_REQUIRED if ACPI > select ACPI_GENERIC_GSI if ACPI > + select ACPI_GTDT if ACPI > select ACPI_REDUCED_HARDWARE_ONLY if ACPI > select ACPI_MCFG if ACPI > select ACPI_SPCR_TABLE if ACPI > diff --git a/drivers/acpi/arm64/Kconfig b/drivers/acpi/arm64/Kconfig > index 4616da4..5a6f80f 100644 > --- a/drivers/acpi/arm64/Kconfig > +++ b/drivers/acpi/arm64/Kconfig > @@ -4,3 +4,6 @@ > > config ACPI_IORT > bool > + > +config ACPI_GTDT > + bool > diff --git a/drivers/acpi/arm64/Makefile b/drivers/acpi/arm64/Makefile > index 72331f2..1017def 100644 > --- a/drivers/acpi/arm64/Makefile > +++ b/drivers/acpi/arm64/Makefile > @@ -1 +1,2 @@ > obj-$(CONFIG_ACPI_IORT) += iort.o > +obj-$(CONFIG_ACPI_GTDT) += gtdt.o > diff --git a/drivers/acpi/arm64/gtdt.c b/drivers/acpi/arm64/gtdt.c > new file mode 100644 > index 0000000..d93a790 > --- /dev/null > +++ b/drivers/acpi/arm64/gtdt.c > @@ -0,0 +1,157 @@ [...] > + > +/** > + * acpi_gtdt_init() - Get the info of GTDT table to prepare for further init. > + * @table: The pointer to GTDT table. > + * @platform_timer_count: The pointer of int variate for returning the > + * number of platform timers. It can be NULL, if > + * driver don't need this info. > + * > + * Return: 0 if success, -EINVAL if error. > + */ > +int __init acpi_gtdt_init(struct acpi_table_header *table, > + int *platform_timer_count) > +{ > + int ret = 0; > + int timer_count = 0; > + void *platform_timer = NULL; > + struct acpi_table_gtdt *gtdt; > + > + gtdt = container_of(table, struct acpi_table_gtdt, header); > + acpi_gtdt_desc.gtdt = gtdt; > + acpi_gtdt_desc.gtdt_end = (void *)table + table->length; > + > + if (table->revision < 2) > + pr_debug("Revision:%d doesn't support Platform Timers.\n", > + table->revision); GTDT table revision is updated to 2 in ACPI 5.1, we will not support ACPI version under 5.1 and disable ACPI in FADT parse before this code is called, so if we get revision <2 here, I think we need to print warning (we need to keep the firmware stick to the spec on ARM64). > + else if (!gtdt->platform_timer_count) > + pr_debug("No Platform Timer.\n"); > + else > + timer_count = gtdt->platform_timer_count; > + > + if (timer_count) { > + platform_timer = (void *)gtdt + gtdt->platform_timer_offset; > + if (platform_timer < (void *)table + > + sizeof(struct acpi_table_gtdt)) { > + pr_err(FW_BUG "invalid timer data.\n"); It's ok but I didn't see other ACPI tables parsing did this check, maybe we can just remove it :) > + timer_count = 0; > + platform_timer = NULL; > + ret = -EINVAL; > + } > + } > + > + acpi_gtdt_desc.platform_timer = platform_timer; > + if (platform_timer_count) > + *platform_timer_count = timer_count; Then the code will much simple: if (gtdt->platform_timer_count) { acpi_gtdt_desc.platform_timer = (void *)gtdt + gtdt->platform_timer_offset; if (platform_timer_count) *platform_timer_count = gtdt->platform_timer_count; } return 0; and remove ret, timer_count and platform_timer. Thanks Hanjun