On Fri, 26 Feb 2016, Shannon Zhao wrote:
> From: Shannon Zhao <shannon.z...@linaro.org>
>
> 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.
>
> Since STAO table and the GIC version are introduced by ACPI 6.0, 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 than 6.0.
>
> Signed-off-by: Hanjun Guo <hanjun....@linaro.org>
> Signed-off-by: Naresh Bhat <naresh.b...@linaro.org>
> Signed-off-by: Parth Dixit <parth.di...@linaro.org>
> Signed-off-by: Shannon Zhao <shannon.z...@linaro.org>
Reviewed-by: Stefano Stabellini <stefano.stabell...@eu.citrix.com>
> V5: only define acpi_psci_present and acpi_psci_hvc_present once
> V4: drop disable_acpi in acpi_parse_fadt
> ---
> xen/arch/arm/acpi/boot.c | 30 ++++++++++++++++++++++++++++++
> xen/arch/arm/acpi/lib.c | 12 ++++++++++++
> xen/include/asm-arm/acpi.h | 3 +++
> 3 files changed, 45 insertions(+)
>
> diff --git a/xen/arch/arm/acpi/boot.c b/xen/arch/arm/acpi/boot.c
> index 1570f7e..6b33fbe 100644
> --- a/xen/arch/arm/acpi/boot.c
> +++ b/xen/arch/arm/acpi/boot.c
> @@ -27,9 +27,32 @@
>
> #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);
> +
> + return -EINVAL;
> +}
> +
> /*
> * acpi_boot_table_init() called from setup_arch(), always.
> * 1. find RSDP and get its address, and then find XSDT
> @@ -54,5 +77,12 @@ 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 f817fe6..a30e4e6 100644
> --- a/xen/arch/arm/acpi/lib.c
> +++ b/xen/arch/arm/acpi/lib.c
> @@ -50,3 +50,15 @@ char *__acpi_map_table(paddr_t phys, unsigned long size)
>
> return ((char *) base + offset);
> }
> +
> +/* 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 10e02bd..f13072f 100644
> --- a/xen/include/asm-arm/acpi.h
> +++ b/xen/include/asm-arm/acpi.h
> @@ -30,6 +30,9 @@
> #define COMPILER_DEPENDENT_UINT64 unsigned long long
> #define ACPI_MAP_MEM_ATTR PAGE_HYPERVISOR
>
> +bool_t __init acpi_psci_present(void);
> +bool_t __init acpi_psci_hvc_present(void);
> +
> #ifdef CONFIG_ACPI
> extern bool_t acpi_disabled;
> /* Basic configuration for ACPI */
> --
> 2.0.4
>
>
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