From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stefano Stabellini Subject: Re: [PATCH v4 06/21] arm/acpi: Parse FADT table and get PSCI flags Date: Wed, 27 Jan 2016 15:41:53 +0000 Message-ID: References: <1453540813-15764-1-git-send-email-zhaoshenglong@huawei.com> <1453540813-15764-7-git-send-email-zhaoshenglong@huawei.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1453540813-15764-7-git-send-email-zhaoshenglong@huawei.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Shannon Zhao Cc: ian.campbell@citrix.com, stefano.stabellini@eu.citrix.com, peter.huangpeng@huawei.com, xen-devel@lists.xen.org, julien.grall@citrix.com, stefano.stabellini@citrix.com, shannon.zhao@linaro.org List-Id: xen-devel@lists.xenproject.org On Sat, 23 Jan 2016, Shannon Zhao wrote: > From: Shannon Zhao > > 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 > Signed-off-by: Naresh Bhat > Signed-off-by: Parth Dixit > Signed-off-by: Shannon Zhao > --- > 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 | 9 +++++++++ > 3 files changed, 51 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 > #include > +#include > +#include > +#include > > #include > > +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; > +} So far so good. > diff --git a/xen/include/asm-arm/acpi.h b/xen/include/asm-arm/acpi.h > index 6a037c9..1ce88f8 100644 > --- a/xen/include/asm-arm/acpi.h > +++ b/xen/include/asm-arm/acpi.h > @@ -31,6 +31,15 @@ > #define ACPI_MAP_MEM_ATTR PAGE_HYPERVISOR > > 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 */ > + > /* Basic configuration for ACPI */ > static inline void disable_acpi(void) > { I would prefer if we only defined each function once, outside the ifdef (no static inline needed). Then we could #ifdef CONFIG_ACPI extern bool_t acpi_disabled; #else #define acpi_disabled (1) #endif Which would solve the problem for !CONFIG_ACPI cases. But you need to be careful to move bool_t acpi_disabled, enable_acpi and disable_acpi inside an ifdef.