Messages in this thread | | | Date | Mon, 18 Aug 2014 19:32:52 +0100 | From | Sudeep Holla <> | Subject | Re: [PATCH v2 05/18] ARM64 / ACPI: Parse FADT table to get PSCI flags for PSCI init |
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On 04/08/14 16:28, Hanjun Guo wrote: > There are two flags: PSCI_COMPLIANT and PSCI_USE_HVC. When set, > the former signals to the OS that the hardware is PSCI compliant. > The latter selects the appropriate conduit for PSCI calls by > toggling between Hypervisor Calls (HVC) and Secure Monitor Calls > (SMC). > > FADT table contains such information, parse FADT to get the flags > for PSCI init. Since ACPI 5.1 doesn't support self defined PSCI > function IDs, which means that only PSCI 0.2+ is supported in ACPI. > > At the same time, only ACPI 5.1 or higher verison supports PSCI, > and FADT Major.Minor version was introduced in ACPI 5.1, so we > will check the version and only parse FADT table with version >= 5.1. > > If firmware provides ACPI tables with ACPI version less than 5.1, > OS will be messed up with those information and have no way to > bring up secondery CPUs, so disable ACPI if we get an FADT table > with version less that 5.1. > > Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org> > Signed-off-by: Graeme Gregory <graeme.gregory@linaro.org> > --- > arch/arm64/include/asm/acpi.h | 12 ++++++ > arch/arm64/kernel/acpi.c | 37 +++++++++++++++++ > arch/arm64/kernel/psci.c | 89 ++++++++++++++++++++++++++++++----------- > arch/arm64/kernel/setup.c | 2 + > 4 files changed, 117 insertions(+), 23 deletions(-) > > diff --git a/arch/arm64/include/asm/acpi.h b/arch/arm64/include/asm/acpi.h > index 6400312..6e04868 100644 > --- a/arch/arm64/include/asm/acpi.h > +++ b/arch/arm64/include/asm/acpi.h > @@ -19,6 +19,18 @@ extern int acpi_disabled; > extern int acpi_noirq; > extern int acpi_pci_disabled; > > +/* 1 to indicate PSCI 0.2+ is implemented */ > +static inline bool acpi_psci_present(void) > +{ > + return !!(acpi_gbl_FADT.arm_boot_flags & ACPI_FADT_PSCI_COMPLIANT); > +} > + > +/* 1 to indicate HVC must be used instead of SMC as the PSCI conduit */ > +static inline bool acpi_psci_use_hvc(void) > +{ > + return !!(acpi_gbl_FADT.arm_boot_flags & ACPI_FADT_PSCI_USE_HVC); > +} > + > static inline void disable_acpi(void) > { > acpi_disabled = 1; > diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c > index 9cf9127..69a315d 100644 > --- a/arch/arm64/kernel/acpi.c > +++ b/arch/arm64/kernel/acpi.c > @@ -11,6 +11,8 @@ > * published by the Free Software Foundation. > */ > > +#define pr_fmt(fmt) "ACPI: " fmt > + > #include <linux/init.h> > #include <linux/acpi.h> > #include <linux/cpumask.h> > @@ -47,6 +49,26 @@ void __init __acpi_unmap_table(char *map, unsigned long size) > early_memunmap(map, size); > } > > +static int __init acpi_parse_fadt(struct acpi_table_header *table) > +{ > + struct acpi_table_fadt *fadt = (struct acpi_table_fadt *)table; > + > + /* > + * Revision in table header is the FADT Major version, > + * and there is a minor version of FADT which was introduced > + * by ACPI 5.1, we only deal with ACPI 5.1 or higher version > + * to get arm boot flags, or we will disable ACPI. > + */ > + if (table->revision < 5 || fadt->minor_revision < 1) {
&&
> + pr_info("FADT version is %d.%d, no PSCI support, should be 5.1 or higher\n", > + table->revision, fadt->minor_revision); > + disable_acpi();
Instead of disabling ACPI at multiple places in the boot sequence, can't it be done once if acpi_boot_init failed ?
> + return -EINVAL; > + } > + > + return 0; > +} > + > /* > * acpi_boot_table_init() called from setup_arch(), always. > * 1. find RSDP and get its address, and then find XSDT > @@ -68,6 +90,21 @@ void __init acpi_boot_table_init(void) > } > } > > +int __init acpi_boot_init(void) > +{ > + int err = 0; > + > + /* If acpi_disabled, bail out */ > + if (acpi_disabled) > + return -ENODEV; > + > + err = acpi_table_parse(ACPI_SIG_FADT, acpi_parse_fadt); > + if (err) > + pr_err("Can't find FADT\n"); > + > + return err; > +} > + > /* > * acpi_suspend_lowlevel() - save kernel state and suspend. > * > diff --git a/arch/arm64/kernel/psci.c b/arch/arm64/kernel/psci.c > index 9e9798f..2ad2084 100644 > --- a/arch/arm64/kernel/psci.c > +++ b/arch/arm64/kernel/psci.c > @@ -15,6 +15,7 @@ > > #define pr_fmt(fmt) "psci: " fmt > > +#include <linux/acpi.h> > #include <linux/init.h> > #include <linux/of.h> > #include <linux/smp.h> > @@ -231,6 +232,33 @@ static void psci_sys_poweroff(void) > invoke_psci_fn(PSCI_0_2_FN_SYSTEM_OFF, 0, 0, 0); > } > > +static void psci_0_2_set_functions(void) > +{ > + pr_info("Using standard PSCI v0.2 function IDs\n"); > + psci_function_id[PSCI_FN_CPU_SUSPEND] = PSCI_0_2_FN64_CPU_SUSPEND; > + psci_ops.cpu_suspend = psci_cpu_suspend; > + > + psci_function_id[PSCI_FN_CPU_OFF] = PSCI_0_2_FN_CPU_OFF; > + psci_ops.cpu_off = psci_cpu_off; > + > + psci_function_id[PSCI_FN_CPU_ON] = PSCI_0_2_FN64_CPU_ON; > + psci_ops.cpu_on = psci_cpu_on; > + > + psci_function_id[PSCI_FN_MIGRATE] = PSCI_0_2_FN64_MIGRATE; > + psci_ops.migrate = psci_migrate; > + > + psci_function_id[PSCI_FN_AFFINITY_INFO] = PSCI_0_2_FN64_AFFINITY_INFO; > + psci_ops.affinity_info = psci_affinity_info; > + > + psci_function_id[PSCI_FN_MIGRATE_INFO_TYPE] = > + PSCI_0_2_FN_MIGRATE_INFO_TYPE; > + psci_ops.migrate_info_type = psci_migrate_info_type; > + > + arm_pm_restart = psci_sys_reset; > + > + pm_power_off = psci_sys_poweroff; > +} > +
Nit: IMO may be you can move these refactoring as separate patch before ACPI related changes ?
> /* > * PSCI Function IDs for v0.2+ are well defined so use > * standard values. > @@ -264,29 +292,7 @@ static int psci_0_2_init(struct device_node *np) > } > } > > - pr_info("Using standard PSCI v0.2 function IDs\n"); > - psci_function_id[PSCI_FN_CPU_SUSPEND] = PSCI_0_2_FN64_CPU_SUSPEND; > - psci_ops.cpu_suspend = psci_cpu_suspend; > - > - psci_function_id[PSCI_FN_CPU_OFF] = PSCI_0_2_FN_CPU_OFF; > - psci_ops.cpu_off = psci_cpu_off; > - > - psci_function_id[PSCI_FN_CPU_ON] = PSCI_0_2_FN64_CPU_ON; > - psci_ops.cpu_on = psci_cpu_on; > - > - psci_function_id[PSCI_FN_MIGRATE] = PSCI_0_2_FN64_MIGRATE; > - psci_ops.migrate = psci_migrate; > - > - psci_function_id[PSCI_FN_AFFINITY_INFO] = PSCI_0_2_FN64_AFFINITY_INFO; > - psci_ops.affinity_info = psci_affinity_info; > - > - psci_function_id[PSCI_FN_MIGRATE_INFO_TYPE] = > - PSCI_0_2_FN_MIGRATE_INFO_TYPE; > - psci_ops.migrate_info_type = psci_migrate_info_type; > - > - arm_pm_restart = psci_sys_reset; > - > - pm_power_off = psci_sys_poweroff; > + psci_0_2_set_functions(); > > out_put_node: > of_node_put(np); > @@ -333,6 +339,40 @@ out_put_node: > return err; > } > > +#ifdef CONFIG_ACPI > +static int get_set_conduit_method_acpi(void) > +{ > + pr_info("probing for conduit method from ACPI.\n"); > + > + if (acpi_psci_use_hvc()) > + invoke_psci_fn = __invoke_psci_fn_hvc; > + else > + invoke_psci_fn = __invoke_psci_fn_smc; > + > + return 0; > +} > + > +/* We use PSCI 0.2+ when ACPI is deployed */ > +static int psci_0_2_init_acpi(void)
May be this can be renamed psci_acpi_init and called from setup directly instead of calling from DT function with acpi_disabled check.
> +{ > + if (!acpi_psci_present()) { > + pr_info("is not implemented in ACPI.\n"); > + return -EOPNOTSUPP; > + } > + > + get_set_conduit_method_acpi(); > + > + psci_0_2_set_functions(); > + > + return 0; > +} > +#else > +static inline int psci_0_2_init_acpi(void) > +{ > + return -ENODEV; > +} > +#endif > + > static const struct of_device_id psci_of_match[] __initconst = { > { .compatible = "arm,psci", .data = psci_0_1_init}, > { .compatible = "arm,psci-0.2", .data = psci_0_2_init}, > @@ -345,6 +385,9 @@ int __init psci_init(void) > const struct of_device_id *matched_np; > psci_initcall_t init_fn; > > + if (!acpi_disabled) > + return psci_0_2_init_acpi(); > +
As mentioned above you need not modify this.
> np = of_find_matching_node_and_match(NULL, psci_of_match, &matched_np); > > if (!np) > diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c > index 85c6326..dfc4e4f3 100644 > --- a/arch/arm64/kernel/setup.c > +++ b/arch/arm64/kernel/setup.c > @@ -395,6 +395,8 @@ void __init setup_arch(char **cmdline_p) > efi_idmap_init(); > > cpu_logical_map(0) = read_cpuid_mpidr() & MPIDR_HWID_BITMASK; > + acpi_boot_init(); > +
Check for the return error here and disable ACPI once rather than at multiple places all over.
> unflatten_device_tree(); > > psci_init(); >
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