Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752188AbdC2OcV (ORCPT ); Wed, 29 Mar 2017 10:32:21 -0400 Received: from mail-it0-f44.google.com ([209.85.214.44]:35308 "EHLO mail-it0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751287AbdC2OcT (ORCPT ); Wed, 29 Mar 2017 10:32:19 -0400 MIME-Version: 1.0 In-Reply-To: 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 22:31:42 +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 Content-Length: 11763 Lines: 359 On 29 March 2017 at 22:29, Fu Wei wrote: > Hi Lorenzo, > > 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. >> >>> 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 ? >> >>> + * 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 >> >>> + */ >>> +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 >> >>> + * >>> + * 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. >> >>> + 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. > > For this problem, Can I do this: > > /** > * acpi_gtdt_init() - Get the info of GTDT table to prepare for further init. > * @table: The pointer to GTDT table. > * @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) > { > void *platform_timer; > 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; > acpi_gtdt_desc.platform_timer = NULL; > if (platform_timer_count) > *platform_timer_count = 0; > > if (table->revision < 2) { > pr_warn("Revision:%d doesn't support Platform Timers.\n", > table->revision); > return 0; > } > > if (!gtdt->platform_timer_count) { > pr_debug("No Platform Timer.\n"); > return 0; > } > if (platform_timer_count) > *platform_timer_count = gtdt->platform_timer_count; sorry , this should be moved, > > 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"); > return -EINVAL; > } > acpi_gtdt_desc.platform_timer = platform_timer; if (platform_timer_count) *platform_timer_count = gtdt->platform_timer_count; Here is the right place > > return 0; > } > > >> >> 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 -- Best regards, Fu Wei Software Engineer Red Hat