From mboxrd@z Thu Jan 1 00:00:00 1970 From: Fu Wei Subject: Re: [PATCH v22 07/11] acpi/arm64: Add GTDT table parse driver Date: Wed, 29 Mar 2017 17:48:17 +0800 Message-ID: References: <20170321163122.9183-1-fu.wei@linaro.org> <20170321163122.9183-8-fu.wei@linaro.org> <20170328113535.GA17440@red-moon> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Return-path: Received: from mail-it0-f46.google.com ([209.85.214.46]:35618 "EHLO mail-it0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755292AbdC2JsT (ORCPT ); Wed, 29 Mar 2017 05:48:19 -0400 Received: by mail-it0-f46.google.com with SMTP id y18so145377808itc.0 for ; Wed, 29 Mar 2017 02:48:18 -0700 (PDT) In-Reply-To: <20170328113535.GA17440@red-moon> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Lorenzo Pieralisi Cc: "Rafael J. Wysocki" , Len Brown , Daniel Lezcano , Thomas Gleixner , Marc Zyngier , Mark Rutland , Sudeep Holla , Hanjun Guo , linux-arm-kernel@lists.infradead.org, Linaro ACPI Mailman List , Linux Kernel Mailing List , ACPI Devel Maling List , rruigrok@codeaurora.org, "Abdulhamid, Harb" , Christopher Covington , Timur Tabi , G Gregory , Al Stone , Jon Masters , Wei Hi Lorenzo, Great thanks for your review and help, I will take most of your suggestions, But one or two comments have been discussed in previous patchset, please allow me to explain these. :-) On 28 March 2017 at 19:35, Lorenzo Pieralisi wrote: > On Wed, Mar 22, 2017 at 12:31:18AM +0800, 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 > > Acked-by: Lorenzo Pieralisi > > Some nits below. Great thanks! > >> Tested-by: Xiongfeng Wang >> Reviewed-by: Hanjun Guo >> Tested-by: Hanjun Guo >> --- >> 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 3741859..7e2baec 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..8a03b4b >> --- /dev/null >> +++ b/drivers/acpi/arm64/gtdt.c >> @@ -0,0 +1,157 @@ >> +/* >> + * ARM Specific GTDT table Support >> + * >> + * Copyright (C) 2016, Linaro Ltd. >> + * Author: Daniel Lezcano >> + * Fu Wei >> + * Hanjun Guo >> + * >> + * This program is free software; you can redistribute it and/or modify >> + * it under the terms of the GNU General Public License version 2 as >> + * published by the Free Software Foundation. >> + */ >> + >> +#include >> +#include >> +#include >> + >> +#include >> + >> +#undef pr_fmt >> +#define pr_fmt(fmt) "ACPI GTDT: " fmt >> + >> +/** >> + * struct acpi_gtdt_descriptor - Store the key info of GTDT for all functions >> + * @gtdt: The pointer to the struct acpi_table_gtdt of GTDT table. >> + * @gtdt_end: The pointer to the end of GTDT table. >> + * @platform_timer: The pointer to the start of Platform Timer Structure >> + * >> + * The struct store the key info of GTDT table, it should be initialized by >> + * acpi_gtdt_init. >> + */ >> +struct acpi_gtdt_descriptor { >> + struct acpi_table_gtdt *gtdt; >> + void *gtdt_end; >> + void *platform_timer; >> +}; >> + >> +static struct acpi_gtdt_descriptor acpi_gtdt_desc __initdata; >> + >> +static int __init map_gt_gsi(u32 interrupt, u32 flags) >> +{ >> + int trigger, polarity; >> + >> + trigger = (flags & ACPI_GTDT_INTERRUPT_MODE) ? ACPI_EDGE_SENSITIVE >> + : ACPI_LEVEL_SENSITIVE; >> + >> + polarity = (flags & ACPI_GTDT_INTERRUPT_POLARITY) ? ACPI_ACTIVE_LOW >> + : ACPI_ACTIVE_HIGH; >> + >> + return acpi_register_gsi(NULL, interrupt, trigger, polarity); >> +} >> + >> +/** >> + * acpi_gtdt_map_ppi() - Map the PPIs of per-cpu arch_timer. >> + * @type: the type of PPI. >> + * >> + * Note: Linux on arm64 isn't supported on the secure side. > > Note: Secure state is not managed by the kernel on ARM64 systems. > > Is that what you wanted to say ? yes, you are right, thanks! :-) Will do so. > >> + * So we only handle the non-secure timer PPIs, >> + * ARCH_TIMER_PHYS_SECURE_PPI is treated as invalid type. >> + * >> + * Return: the mapped PPI value, 0 if error. >> + */ >> +int __init acpi_gtdt_map_ppi(int type) >> +{ >> + struct acpi_table_gtdt *gtdt = acpi_gtdt_desc.gtdt; >> + >> + switch (type) { >> + case ARCH_TIMER_PHYS_NONSECURE_PPI: >> + return map_gt_gsi(gtdt->non_secure_el1_interrupt, >> + gtdt->non_secure_el1_flags); >> + case ARCH_TIMER_VIRT_PPI: >> + return map_gt_gsi(gtdt->virtual_timer_interrupt, >> + gtdt->virtual_timer_flags); >> + >> + case ARCH_TIMER_HYP_PPI: >> + return map_gt_gsi(gtdt->non_secure_el2_interrupt, >> + gtdt->non_secure_el2_flags); >> + default: >> + pr_err("Failed to map timer interrupt: invalid type.\n"); >> + } >> + >> + return 0; >> +} >> + >> +/** >> + * acpi_gtdt_c3stop() - Got c3stop info from GTDT according to the type of PPI. >> + * @type: the type of PPI. >> + * >> + * Return: 1 if the timer can be in deep idle state, 0 otherwise. > > Return: true if the timer HW state is lost when a CPU enters an idle > state, false otherwise Thanks , will do > >> + */ >> +bool __init acpi_gtdt_c3stop(int type) >> +{ >> + struct acpi_table_gtdt *gtdt = acpi_gtdt_desc.gtdt; >> + >> + switch (type) { >> + case ARCH_TIMER_PHYS_NONSECURE_PPI: >> + return !(gtdt->non_secure_el1_flags & ACPI_GTDT_ALWAYS_ON); >> + >> + case ARCH_TIMER_VIRT_PPI: >> + return !(gtdt->virtual_timer_flags & ACPI_GTDT_ALWAYS_ON); >> + >> + case ARCH_TIMER_HYP_PPI: >> + return !(gtdt->non_secure_el2_flags & ACPI_GTDT_ALWAYS_ON); >> + >> + default: >> + pr_err("Failed to get c3stop info: invalid type.\n"); >> + } >> + >> + return 0; >> +} >> + >> +/** >> + * 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 > > I do not understand what this means. > >> + * number of platform timers. It can be NULL, if >> + * driver don't need this info. > > driver doesn't Sorry, this is not clear, I will fix it by : * @platform_timer_count: It points to a integer variable which is used * for storing the number of platform timers. * This pointer could be NULL, if the caller * doesn'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_warn("Revision:%d doesn't support Platform Timers.\n", >> + table->revision); > > Ok, two points here. First, I am not sure why you should warn if the > table revision is < 2, is that a FW bug ? I do not think it is, you > can just return 0. I used pr_debug here before v20, then I got Hanjun's suggestion: ------- 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). ------- https://lkml.org/lkml/2017/1/19/82 So I started to use pr_warn. > >> + else if (!gtdt->platform_timer_count) >> + pr_debug("No Platform Timer.\n"); > > Ditto. Why keep executing ? There is nothing to do, just bail out > with a return 0. > >> + 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"); >> + timer_count = 0; >> + platform_timer = NULL; >> + ret = -EINVAL; > > Same here, I suspect you want to consolidate the return path (I missed > previous rounds of reviews so you should not worry too much, I can clean > this up later) but to me a: > > return -EINVAL; > > would just do. yes, you are right, I try to consolidate the return path. :-) It may can return earlier, let me try. > > Lorenzo > >> + } >> + } >> + >> + acpi_gtdt_desc.platform_timer = platform_timer; >> + if (platform_timer_count) >> + *platform_timer_count = timer_count; >> + >> + return ret; >> +} >> diff --git a/include/linux/acpi.h b/include/linux/acpi.h >> index 9b05886..4b5c146 100644 >> --- a/include/linux/acpi.h >> +++ b/include/linux/acpi.h >> @@ -595,6 +595,12 @@ enum acpi_reconfig_event { >> int acpi_reconfig_notifier_register(struct notifier_block *nb); >> int acpi_reconfig_notifier_unregister(struct notifier_block *nb); >> >> +#ifdef CONFIG_ACPI_GTDT >> +int acpi_gtdt_init(struct acpi_table_header *table, int *platform_timer_count); >> +int acpi_gtdt_map_ppi(int type); >> +bool acpi_gtdt_c3stop(int type); >> +#endif >> + >> #else /* !CONFIG_ACPI */ >> >> #define acpi_disabled 1 >> -- >> 2.9.3 >> -- Best regards, Fu Wei Software Engineer Red Hat From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755642AbdC2Js0 (ORCPT ); Wed, 29 Mar 2017 05:48:26 -0400 Received: from mail-it0-f41.google.com ([209.85.214.41]:37991 "EHLO mail-it0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755292AbdC2JsY (ORCPT ); Wed, 29 Mar 2017 05:48:24 -0400 MIME-Version: 1.0 In-Reply-To: <20170328113535.GA17440@red-moon> References: <20170321163122.9183-1-fu.wei@linaro.org> <20170321163122.9183-8-fu.wei@linaro.org> <20170328113535.GA17440@red-moon> From: Fu Wei Date: Wed, 29 Mar 2017 17:48:17 +0800 Message-ID: Subject: Re: [PATCH v22 07/11] acpi/arm64: Add GTDT table parse driver To: Lorenzo Pieralisi Cc: "Rafael J. Wysocki" , Len Brown , Daniel Lezcano , Thomas Gleixner , Marc Zyngier , Mark Rutland , Sudeep Holla , Hanjun Guo , linux-arm-kernel@lists.infradead.org, Linaro ACPI Mailman List , Linux Kernel Mailing List , ACPI Devel Maling List , rruigrok@codeaurora.org, "Abdulhamid, Harb" , Christopher Covington , Timur Tabi , G Gregory , Al Stone , Jon Masters , Wei Huang , Arnd Bergmann , Catalin Marinas , Will Deacon , Suravee Suthikulpanit , Leo Duran , Wim Van Sebroeck , Guenter Roeck , linux-watchdog@vger.kernel.org, Tomasz Nowicki , Christoffer Dall , Julien Grall Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Lorenzo, Great thanks for your review and help, I will take most of your suggestions, But one or two comments have been discussed in previous patchset, please allow me to explain these. :-) On 28 March 2017 at 19:35, Lorenzo Pieralisi wrote: > On Wed, Mar 22, 2017 at 12:31:18AM +0800, 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 > > Acked-by: Lorenzo Pieralisi > > Some nits below. Great thanks! > >> Tested-by: Xiongfeng Wang >> Reviewed-by: Hanjun Guo >> Tested-by: Hanjun Guo >> --- >> 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 3741859..7e2baec 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..8a03b4b >> --- /dev/null >> +++ b/drivers/acpi/arm64/gtdt.c >> @@ -0,0 +1,157 @@ >> +/* >> + * ARM Specific GTDT table Support >> + * >> + * Copyright (C) 2016, Linaro Ltd. >> + * Author: Daniel Lezcano >> + * Fu Wei >> + * Hanjun Guo >> + * >> + * This program is free software; you can redistribute it and/or modify >> + * it under the terms of the GNU General Public License version 2 as >> + * published by the Free Software Foundation. >> + */ >> + >> +#include >> +#include >> +#include >> + >> +#include >> + >> +#undef pr_fmt >> +#define pr_fmt(fmt) "ACPI GTDT: " fmt >> + >> +/** >> + * struct acpi_gtdt_descriptor - Store the key info of GTDT for all functions >> + * @gtdt: The pointer to the struct acpi_table_gtdt of GTDT table. >> + * @gtdt_end: The pointer to the end of GTDT table. >> + * @platform_timer: The pointer to the start of Platform Timer Structure >> + * >> + * The struct store the key info of GTDT table, it should be initialized by >> + * acpi_gtdt_init. >> + */ >> +struct acpi_gtdt_descriptor { >> + struct acpi_table_gtdt *gtdt; >> + void *gtdt_end; >> + void *platform_timer; >> +}; >> + >> +static struct acpi_gtdt_descriptor acpi_gtdt_desc __initdata; >> + >> +static int __init map_gt_gsi(u32 interrupt, u32 flags) >> +{ >> + int trigger, polarity; >> + >> + trigger = (flags & ACPI_GTDT_INTERRUPT_MODE) ? ACPI_EDGE_SENSITIVE >> + : ACPI_LEVEL_SENSITIVE; >> + >> + polarity = (flags & ACPI_GTDT_INTERRUPT_POLARITY) ? ACPI_ACTIVE_LOW >> + : ACPI_ACTIVE_HIGH; >> + >> + return acpi_register_gsi(NULL, interrupt, trigger, polarity); >> +} >> + >> +/** >> + * acpi_gtdt_map_ppi() - Map the PPIs of per-cpu arch_timer. >> + * @type: the type of PPI. >> + * >> + * Note: Linux on arm64 isn't supported on the secure side. > > Note: Secure state is not managed by the kernel on ARM64 systems. > > Is that what you wanted to say ? yes, you are right, thanks! :-) Will do so. > >> + * So we only handle the non-secure timer PPIs, >> + * ARCH_TIMER_PHYS_SECURE_PPI is treated as invalid type. >> + * >> + * Return: the mapped PPI value, 0 if error. >> + */ >> +int __init acpi_gtdt_map_ppi(int type) >> +{ >> + struct acpi_table_gtdt *gtdt = acpi_gtdt_desc.gtdt; >> + >> + switch (type) { >> + case ARCH_TIMER_PHYS_NONSECURE_PPI: >> + return map_gt_gsi(gtdt->non_secure_el1_interrupt, >> + gtdt->non_secure_el1_flags); >> + case ARCH_TIMER_VIRT_PPI: >> + return map_gt_gsi(gtdt->virtual_timer_interrupt, >> + gtdt->virtual_timer_flags); >> + >> + case ARCH_TIMER_HYP_PPI: >> + return map_gt_gsi(gtdt->non_secure_el2_interrupt, >> + gtdt->non_secure_el2_flags); >> + default: >> + pr_err("Failed to map timer interrupt: invalid type.\n"); >> + } >> + >> + return 0; >> +} >> + >> +/** >> + * acpi_gtdt_c3stop() - Got c3stop info from GTDT according to the type of PPI. >> + * @type: the type of PPI. >> + * >> + * Return: 1 if the timer can be in deep idle state, 0 otherwise. > > Return: true if the timer HW state is lost when a CPU enters an idle > state, false otherwise Thanks , will do > >> + */ >> +bool __init acpi_gtdt_c3stop(int type) >> +{ >> + struct acpi_table_gtdt *gtdt = acpi_gtdt_desc.gtdt; >> + >> + switch (type) { >> + case ARCH_TIMER_PHYS_NONSECURE_PPI: >> + return !(gtdt->non_secure_el1_flags & ACPI_GTDT_ALWAYS_ON); >> + >> + case ARCH_TIMER_VIRT_PPI: >> + return !(gtdt->virtual_timer_flags & ACPI_GTDT_ALWAYS_ON); >> + >> + case ARCH_TIMER_HYP_PPI: >> + return !(gtdt->non_secure_el2_flags & ACPI_GTDT_ALWAYS_ON); >> + >> + default: >> + pr_err("Failed to get c3stop info: invalid type.\n"); >> + } >> + >> + return 0; >> +} >> + >> +/** >> + * 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 > > I do not understand what this means. > >> + * number of platform timers. It can be NULL, if >> + * driver don't need this info. > > driver doesn't Sorry, this is not clear, I will fix it by : * @platform_timer_count: It points to a integer variable which is used * for storing the number of platform timers. * This pointer could be NULL, if the caller * doesn'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_warn("Revision:%d doesn't support Platform Timers.\n", >> + table->revision); > > Ok, two points here. First, I am not sure why you should warn if the > table revision is < 2, is that a FW bug ? I do not think it is, you > can just return 0. I used pr_debug here before v20, then I got Hanjun's suggestion: ------- 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). ------- https://lkml.org/lkml/2017/1/19/82 So I started to use pr_warn. > >> + else if (!gtdt->platform_timer_count) >> + pr_debug("No Platform Timer.\n"); > > Ditto. Why keep executing ? There is nothing to do, just bail out > with a return 0. > >> + 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"); >> + timer_count = 0; >> + platform_timer = NULL; >> + ret = -EINVAL; > > Same here, I suspect you want to consolidate the return path (I missed > previous rounds of reviews so you should not worry too much, I can clean > this up later) but to me a: > > return -EINVAL; > > would just do. yes, you are right, I try to consolidate the return path. :-) It may can return earlier, let me try. > > Lorenzo > >> + } >> + } >> + >> + acpi_gtdt_desc.platform_timer = platform_timer; >> + if (platform_timer_count) >> + *platform_timer_count = timer_count; >> + >> + return ret; >> +} >> diff --git a/include/linux/acpi.h b/include/linux/acpi.h >> index 9b05886..4b5c146 100644 >> --- a/include/linux/acpi.h >> +++ b/include/linux/acpi.h >> @@ -595,6 +595,12 @@ enum acpi_reconfig_event { >> int acpi_reconfig_notifier_register(struct notifier_block *nb); >> int acpi_reconfig_notifier_unregister(struct notifier_block *nb); >> >> +#ifdef CONFIG_ACPI_GTDT >> +int acpi_gtdt_init(struct acpi_table_header *table, int *platform_timer_count); >> +int acpi_gtdt_map_ppi(int type); >> +bool acpi_gtdt_c3stop(int type); >> +#endif >> + >> #else /* !CONFIG_ACPI */ >> >> #define acpi_disabled 1 >> -- >> 2.9.3 >> -- Best regards, Fu Wei Software Engineer Red Hat From mboxrd@z Thu Jan 1 00:00:00 1970 From: fu.wei@linaro.org (Fu Wei) Date: Wed, 29 Mar 2017 17:48:17 +0800 Subject: [PATCH v22 07/11] acpi/arm64: Add GTDT table parse driver In-Reply-To: <20170328113535.GA17440@red-moon> References: <20170321163122.9183-1-fu.wei@linaro.org> <20170321163122.9183-8-fu.wei@linaro.org> <20170328113535.GA17440@red-moon> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Lorenzo, Great thanks for your review and help, I will take most of your suggestions, But one or two comments have been discussed in previous patchset, please allow me to explain these. :-) On 28 March 2017 at 19:35, Lorenzo Pieralisi wrote: > On Wed, Mar 22, 2017 at 12:31:18AM +0800, fu.wei at 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 > > Acked-by: Lorenzo Pieralisi > > Some nits below. Great thanks! > >> Tested-by: Xiongfeng Wang >> Reviewed-by: Hanjun Guo >> Tested-by: Hanjun Guo >> --- >> 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 3741859..7e2baec 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..8a03b4b >> --- /dev/null >> +++ b/drivers/acpi/arm64/gtdt.c >> @@ -0,0 +1,157 @@ >> +/* >> + * ARM Specific GTDT table Support >> + * >> + * Copyright (C) 2016, Linaro Ltd. >> + * Author: Daniel Lezcano >> + * Fu Wei >> + * Hanjun Guo >> + * >> + * This program is free software; you can redistribute it and/or modify >> + * it under the terms of the GNU General Public License version 2 as >> + * published by the Free Software Foundation. >> + */ >> + >> +#include >> +#include >> +#include >> + >> +#include >> + >> +#undef pr_fmt >> +#define pr_fmt(fmt) "ACPI GTDT: " fmt >> + >> +/** >> + * struct acpi_gtdt_descriptor - Store the key info of GTDT for all functions >> + * @gtdt: The pointer to the struct acpi_table_gtdt of GTDT table. >> + * @gtdt_end: The pointer to the end of GTDT table. >> + * @platform_timer: The pointer to the start of Platform Timer Structure >> + * >> + * The struct store the key info of GTDT table, it should be initialized by >> + * acpi_gtdt_init. >> + */ >> +struct acpi_gtdt_descriptor { >> + struct acpi_table_gtdt *gtdt; >> + void *gtdt_end; >> + void *platform_timer; >> +}; >> + >> +static struct acpi_gtdt_descriptor acpi_gtdt_desc __initdata; >> + >> +static int __init map_gt_gsi(u32 interrupt, u32 flags) >> +{ >> + int trigger, polarity; >> + >> + trigger = (flags & ACPI_GTDT_INTERRUPT_MODE) ? ACPI_EDGE_SENSITIVE >> + : ACPI_LEVEL_SENSITIVE; >> + >> + polarity = (flags & ACPI_GTDT_INTERRUPT_POLARITY) ? ACPI_ACTIVE_LOW >> + : ACPI_ACTIVE_HIGH; >> + >> + return acpi_register_gsi(NULL, interrupt, trigger, polarity); >> +} >> + >> +/** >> + * acpi_gtdt_map_ppi() - Map the PPIs of per-cpu arch_timer. >> + * @type: the type of PPI. >> + * >> + * Note: Linux on arm64 isn't supported on the secure side. > > Note: Secure state is not managed by the kernel on ARM64 systems. > > Is that what you wanted to say ? yes, you are right, thanks! :-) Will do so. > >> + * So we only handle the non-secure timer PPIs, >> + * ARCH_TIMER_PHYS_SECURE_PPI is treated as invalid type. >> + * >> + * Return: the mapped PPI value, 0 if error. >> + */ >> +int __init acpi_gtdt_map_ppi(int type) >> +{ >> + struct acpi_table_gtdt *gtdt = acpi_gtdt_desc.gtdt; >> + >> + switch (type) { >> + case ARCH_TIMER_PHYS_NONSECURE_PPI: >> + return map_gt_gsi(gtdt->non_secure_el1_interrupt, >> + gtdt->non_secure_el1_flags); >> + case ARCH_TIMER_VIRT_PPI: >> + return map_gt_gsi(gtdt->virtual_timer_interrupt, >> + gtdt->virtual_timer_flags); >> + >> + case ARCH_TIMER_HYP_PPI: >> + return map_gt_gsi(gtdt->non_secure_el2_interrupt, >> + gtdt->non_secure_el2_flags); >> + default: >> + pr_err("Failed to map timer interrupt: invalid type.\n"); >> + } >> + >> + return 0; >> +} >> + >> +/** >> + * acpi_gtdt_c3stop() - Got c3stop info from GTDT according to the type of PPI. >> + * @type: the type of PPI. >> + * >> + * Return: 1 if the timer can be in deep idle state, 0 otherwise. > > Return: true if the timer HW state is lost when a CPU enters an idle > state, false otherwise Thanks , will do > >> + */ >> +bool __init acpi_gtdt_c3stop(int type) >> +{ >> + struct acpi_table_gtdt *gtdt = acpi_gtdt_desc.gtdt; >> + >> + switch (type) { >> + case ARCH_TIMER_PHYS_NONSECURE_PPI: >> + return !(gtdt->non_secure_el1_flags & ACPI_GTDT_ALWAYS_ON); >> + >> + case ARCH_TIMER_VIRT_PPI: >> + return !(gtdt->virtual_timer_flags & ACPI_GTDT_ALWAYS_ON); >> + >> + case ARCH_TIMER_HYP_PPI: >> + return !(gtdt->non_secure_el2_flags & ACPI_GTDT_ALWAYS_ON); >> + >> + default: >> + pr_err("Failed to get c3stop info: invalid type.\n"); >> + } >> + >> + return 0; >> +} >> + >> +/** >> + * 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 > > I do not understand what this means. > >> + * number of platform timers. It can be NULL, if >> + * driver don't need this info. > > driver doesn't Sorry, this is not clear, I will fix it by : * @platform_timer_count: It points to a integer variable which is used * for storing the number of platform timers. * This pointer could be NULL, if the caller * doesn'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_warn("Revision:%d doesn't support Platform Timers.\n", >> + table->revision); > > Ok, two points here. First, I am not sure why you should warn if the > table revision is < 2, is that a FW bug ? I do not think it is, you > can just return 0. I used pr_debug here before v20, then I got Hanjun's suggestion: ------- 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). ------- https://lkml.org/lkml/2017/1/19/82 So I started to use pr_warn. > >> + else if (!gtdt->platform_timer_count) >> + pr_debug("No Platform Timer.\n"); > > Ditto. Why keep executing ? There is nothing to do, just bail out > with a return 0. > >> + 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"); >> + timer_count = 0; >> + platform_timer = NULL; >> + ret = -EINVAL; > > Same here, I suspect you want to consolidate the return path (I missed > previous rounds of reviews so you should not worry too much, I can clean > this up later) but to me a: > > return -EINVAL; > > would just do. yes, you are right, I try to consolidate the return path. :-) It may can return earlier, let me try. > > Lorenzo > >> + } >> + } >> + >> + acpi_gtdt_desc.platform_timer = platform_timer; >> + if (platform_timer_count) >> + *platform_timer_count = timer_count; >> + >> + return ret; >> +} >> diff --git a/include/linux/acpi.h b/include/linux/acpi.h >> index 9b05886..4b5c146 100644 >> --- a/include/linux/acpi.h >> +++ b/include/linux/acpi.h >> @@ -595,6 +595,12 @@ enum acpi_reconfig_event { >> int acpi_reconfig_notifier_register(struct notifier_block *nb); >> int acpi_reconfig_notifier_unregister(struct notifier_block *nb); >> >> +#ifdef CONFIG_ACPI_GTDT >> +int acpi_gtdt_init(struct acpi_table_header *table, int *platform_timer_count); >> +int acpi_gtdt_map_ppi(int type); >> +bool acpi_gtdt_c3stop(int type); >> +#endif >> + >> #else /* !CONFIG_ACPI */ >> >> #define acpi_disabled 1 >> -- >> 2.9.3 >> -- Best regards, Fu Wei Software Engineer Red Hat