[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH v3 13/62] arm/acpi: Parse FADT table and get PSCI flags
On Tue, 17 Nov 2015, shannon.zhao@xxxxxxxxxx wrote: > From: Shannon Zhao <shannon.zhao@xxxxxxxxxx> > > 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 furture usage. At the same time, only ACPI 5.1 or higher verison > supports PSCI, and FADT Major.Minor version was introduced in ACPI > 5.1, but for Xen it needs FADT hypervisor_id introduced by ACPI 6.0 to > tell Dom0 that it runs on Xen hypervisor, so we will check the version > and only parse FADT table with version >= 6.0. > > If firmware provides ACPI tables with ACPI version less than 6.0, > OS will be messed up with those information, so disable ACPI if we > get an FADT table with version less that 6.0. > > Signed-off-by: Hanjun Guo <hanjun.guo@xxxxxxxxxx> > Signed-off-by: Naresh Bhat <naresh.bhat@xxxxxxxxxx> > Signed-off-by: Parth Dixit <parth.dixit@xxxxxxxxxx> > Signed-off-by: Shannon Zhao <shannon.zhao@xxxxxxxxxx> > --- > xen/arch/arm/acpi/boot.c | 31 +++++++++++++++++++++++++++++++ > xen/arch/arm/acpi/lib.c | 12 ++++++++++++ > xen/include/asm-arm/acpi.h | 9 +++++++++ > 3 files changed, 52 insertions(+) > > diff --git a/xen/arch/arm/acpi/boot.c b/xen/arch/arm/acpi/boot.c > index ad51afc..0fabe7d 100644 > --- a/xen/arch/arm/acpi/boot.c > +++ b/xen/arch/arm/acpi/boot.c > @@ -27,9 +27,33 @@ > > #include <xen/init.h> > #include <xen/acpi.h> > +#include <xen/errno.h> > +#include <acpi/actables.h> > +#include <xen/mm.h> > > #include <asm/acpi.h> > > +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 revision, and there > + * is a minor revision of FADT which was introduced by ACPI 6.0, > + * we only deal with ACPI 6.0 or newer revision to get GIC and SMP > + * boot protocol configuration data, or we will disable ACPI. > + */ > + if ( table->revision > 6 > + || (table->revision == 6 && fadt->minor_revision >= 0) ) > + return 0; > + > + printk("Unsupported FADT revision %d.%d, should be 6.0+, will disable > ACPI\n", > + table->revision, fadt->minor_revision); > + disable_acpi(); This call to disable_acpi is redundant, given the other call below > + return -EINVAL; > +} > + > /* > * acpi_boot_table_init() called from setup_arch(), always. > * 1. find RSDP and get its address, and then find XSDT > @@ -58,5 +82,12 @@ int __init acpi_boot_table_init(void) > return error; > } > > + if ( acpi_table_parse(ACPI_SIG_FADT, acpi_parse_fadt) ) > + { > + /* disable ACPI if no FADT is found */ > + disable_acpi(); > + printk("Can't find FADT\n"); > + } > + > return 0; > } > diff --git a/xen/arch/arm/acpi/lib.c b/xen/arch/arm/acpi/lib.c > index b68623b..d8b7635 100644 > --- a/xen/arch/arm/acpi/lib.c > +++ b/xen/arch/arm/acpi/lib.c > @@ -31,3 +31,15 @@ arch_acpi_os_map_memory(acpi_physical_address phys, > acpi_size size) > { > return __va(phys); > } > + > +/* 1 to indicate PSCI 0.2+ is implemented */ > +bool_t __init acpi_psci_present(void) > +{ > + return acpi_gbl_FADT.arm_boot_flags & ACPI_FADT_PSCI_COMPLIANT; > +} > + > +/* 1 to indicate HVC is present instead of SMC as the PSCI conduit */ > +bool_t __init acpi_psci_hvc_present(void) > +{ > + return acpi_gbl_FADT.arm_boot_flags & ACPI_FADT_PSCI_USE_HVC; > +} > diff --git a/xen/include/asm-arm/acpi.h b/xen/include/asm-arm/acpi.h > index e41e03b..65f80b1 100644 > --- a/xen/include/asm-arm/acpi.h > +++ b/xen/include/asm-arm/acpi.h > @@ -29,6 +29,15 @@ > #define COMPILER_DEPENDENT_UINT64 unsigned long long > > extern bool_t acpi_disabled; > + > +#ifdef CONFIG_ACPI > +bool_t __init acpi_psci_present(void); > +bool_t __init acpi_psci_hvc_present(void); > +#else > +static inline bool_t acpi_psci_present(void) { return false; } > +static inline bool_t acpi_psci_hvc_present(void) {return false; } > +#endif /* CONFIG_ACPI */ It doesn't look like this is necessary on x86, acpi_gbl_FADT is used in a few places, including xen/arch/x86/time.c, without checking for CONFIG_ACPI or HAS_ACPI. Is the x86 code wrong? > /* Basic configuration for ACPI */ > static inline void disable_acpi(void) > { > -- > 2.1.0 > _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
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