| Message ID | 1465315583-1278-12-git-send-email-julien.grall@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, 7 Jun 2016, Julien Grall wrote: > After each CPU has been started, we iterate through a list of CPU > errata to detect CPUs which need from hypervisor code patches. > > For each bug there is a function which check if that a particular CPU is > affected. This needs to be done on every CPUs to cover heterogenous > system properly. > > If a certain erratum has been detected, the capability bit will be set. > In the case the erratum requires code patching, this will be triggered > by the call to apply_alternatives. > > The code is based on the file arch/arm64/kernel/cpu_errata.c in Linux > v4.6-rc3. > > Signed-off-by: Julien Grall <julien.grall@arm.com> Regardless of the disagreement on the number of parameters to update_cpu_capabilities: Acked-by: Stefano Stabellini <sstabellini@kernel.org> > Changes in v3: > - Move update_cpu_capabilities in a separate patch > - Update the commit message to mention that workaround may > not require code patching. > > Changes in v2: > - Use XENLOG_INFO for the loglevel of the message > --- > xen/arch/arm/Makefile | 1 + > xen/arch/arm/cpuerrata.c | 26 ++++++++++++++++++++++++++ > xen/arch/arm/setup.c | 3 +++ > xen/arch/arm/smpboot.c | 3 +++ > xen/include/asm-arm/cpuerrata.h | 6 ++++++ > xen/include/asm-arm/cpufeature.h | 6 ++++++ > 6 files changed, 45 insertions(+) > create mode 100644 xen/arch/arm/cpuerrata.c > create mode 100644 xen/include/asm-arm/cpuerrata.h > > diff --git a/xen/arch/arm/Makefile b/xen/arch/arm/Makefile > index 67ccc43..a90ecf3 100644 > --- a/xen/arch/arm/Makefile > +++ b/xen/arch/arm/Makefile > @@ -7,6 +7,7 @@ subdir-$(CONFIG_ACPI) += acpi > obj-$(CONFIG_ALTERNATIVE) += alternative.o > obj-y += bootfdt.o > obj-y += cpu.o > +obj-y += cpuerrata.o > obj-y += cpufeature.o > obj-y += decode.o > obj-y += device.o > diff --git a/xen/arch/arm/cpuerrata.c b/xen/arch/arm/cpuerrata.c > new file mode 100644 > index 0000000..52d39f8 > --- /dev/null > +++ b/xen/arch/arm/cpuerrata.c > @@ -0,0 +1,26 @@ > +#include <xen/config.h> > +#include <asm/cpufeature.h> > +#include <asm/cpuerrata.h> > + > +#define MIDR_RANGE(model, min, max) \ > + .matches = is_affected_midr_range, \ > + .midr_model = model, \ > + .midr_range_min = min, \ > + .midr_range_max = max > + > +static bool_t __maybe_unused > +is_affected_midr_range(const struct arm_cpu_capabilities *entry) > +{ > + return MIDR_IS_CPU_MODEL_RANGE(boot_cpu_data.midr.bits, entry->midr_model, > + entry->midr_range_min, > + entry->midr_range_max); > +} > + > +static const struct arm_cpu_capabilities arm_errata[] = { > + {}, > +}; > + > +void check_local_cpu_errata(void) > +{ > + update_cpu_capabilities(arm_errata, "enabled workaround for"); > +} > diff --git a/xen/arch/arm/setup.c b/xen/arch/arm/setup.c > index 01e2900..6e34bea 100644 > --- a/xen/arch/arm/setup.c > +++ b/xen/arch/arm/setup.c > @@ -43,6 +43,7 @@ > #include <asm/current.h> > #include <asm/setup.h> > #include <asm/gic.h> > +#include <asm/cpuerrata.h> > #include <asm/cpufeature.h> > #include <asm/platform.h> > #include <asm/procinfo.h> > @@ -171,6 +172,8 @@ static void __init processor_id(void) > } > > processor_setup(); > + > + check_local_cpu_errata(); > } > > void dt_unreserved_regions(paddr_t s, paddr_t e, > diff --git a/xen/arch/arm/smpboot.c b/xen/arch/arm/smpboot.c > index ba83406..fdd11b5 100644 > --- a/xen/arch/arm/smpboot.c > +++ b/xen/arch/arm/smpboot.c > @@ -29,6 +29,7 @@ > #include <xen/timer.h> > #include <xen/irq.h> > #include <xen/console.h> > +#include <asm/cpuerrata.h> > #include <asm/gic.h> > #include <asm/psci.h> > #include <asm/acpi.h> > @@ -317,6 +318,8 @@ void start_secondary(unsigned long boot_phys_offset, > local_irq_enable(); > local_abort_enable(); > > + check_local_cpu_errata(); > + > printk(XENLOG_DEBUG "CPU %u booted.\n", smp_processor_id()); > > startup_cpu_idle_loop(); > diff --git a/xen/include/asm-arm/cpuerrata.h b/xen/include/asm-arm/cpuerrata.h > new file mode 100644 > index 0000000..8ffd7ba > --- /dev/null > +++ b/xen/include/asm-arm/cpuerrata.h > @@ -0,0 +1,6 @@ > +#ifndef __ARM_CPUERRATA_H > +#define __ARM_CPUERRATA_H > + > +void check_local_cpu_errata(void); > + > +#endif /* __ARM_CPUERRATA_H */ > diff --git a/xen/include/asm-arm/cpufeature.h b/xen/include/asm-arm/cpufeature.h > index be2414c..fb57295 100644 > --- a/xen/include/asm-arm/cpufeature.h > +++ b/xen/include/asm-arm/cpufeature.h > @@ -66,6 +66,12 @@ struct arm_cpu_capabilities { > const char *desc; > u16 capability; > bool_t (*matches)(const struct arm_cpu_capabilities *); > + union { > + struct { /* To be used for eratum handling only */ > + u32 midr_model; > + u32 midr_range_min, midr_range_max; > + }; > + }; > }; > > void update_cpu_capabilities(const struct arm_cpu_capabilities *caps, > -- > 1.9.1 >
diff --git a/xen/arch/arm/Makefile b/xen/arch/arm/Makefile index 67ccc43..a90ecf3 100644 --- a/xen/arch/arm/Makefile +++ b/xen/arch/arm/Makefile @@ -7,6 +7,7 @@ subdir-$(CONFIG_ACPI) += acpi obj-$(CONFIG_ALTERNATIVE) += alternative.o obj-y += bootfdt.o obj-y += cpu.o +obj-y += cpuerrata.o obj-y += cpufeature.o obj-y += decode.o obj-y += device.o diff --git a/xen/arch/arm/cpuerrata.c b/xen/arch/arm/cpuerrata.c new file mode 100644 index 0000000..52d39f8 --- /dev/null +++ b/xen/arch/arm/cpuerrata.c @@ -0,0 +1,26 @@ +#include <xen/config.h> +#include <asm/cpufeature.h> +#include <asm/cpuerrata.h> + +#define MIDR_RANGE(model, min, max) \ + .matches = is_affected_midr_range, \ + .midr_model = model, \ + .midr_range_min = min, \ + .midr_range_max = max + +static bool_t __maybe_unused +is_affected_midr_range(const struct arm_cpu_capabilities *entry) +{ + return MIDR_IS_CPU_MODEL_RANGE(boot_cpu_data.midr.bits, entry->midr_model, + entry->midr_range_min, + entry->midr_range_max); +} + +static const struct arm_cpu_capabilities arm_errata[] = { + {}, +}; + +void check_local_cpu_errata(void) +{ + update_cpu_capabilities(arm_errata, "enabled workaround for"); +} diff --git a/xen/arch/arm/setup.c b/xen/arch/arm/setup.c index 01e2900..6e34bea 100644 --- a/xen/arch/arm/setup.c +++ b/xen/arch/arm/setup.c @@ -43,6 +43,7 @@ #include <asm/current.h> #include <asm/setup.h> #include <asm/gic.h> +#include <asm/cpuerrata.h> #include <asm/cpufeature.h> #include <asm/platform.h> #include <asm/procinfo.h> @@ -171,6 +172,8 @@ static void __init processor_id(void) } processor_setup(); + + check_local_cpu_errata(); } void dt_unreserved_regions(paddr_t s, paddr_t e, diff --git a/xen/arch/arm/smpboot.c b/xen/arch/arm/smpboot.c index ba83406..fdd11b5 100644 --- a/xen/arch/arm/smpboot.c +++ b/xen/arch/arm/smpboot.c @@ -29,6 +29,7 @@ #include <xen/timer.h> #include <xen/irq.h> #include <xen/console.h> +#include <asm/cpuerrata.h> #include <asm/gic.h> #include <asm/psci.h> #include <asm/acpi.h> @@ -317,6 +318,8 @@ void start_secondary(unsigned long boot_phys_offset, local_irq_enable(); local_abort_enable(); + check_local_cpu_errata(); + printk(XENLOG_DEBUG "CPU %u booted.\n", smp_processor_id()); startup_cpu_idle_loop(); diff --git a/xen/include/asm-arm/cpuerrata.h b/xen/include/asm-arm/cpuerrata.h new file mode 100644 index 0000000..8ffd7ba --- /dev/null +++ b/xen/include/asm-arm/cpuerrata.h @@ -0,0 +1,6 @@ +#ifndef __ARM_CPUERRATA_H +#define __ARM_CPUERRATA_H + +void check_local_cpu_errata(void); + +#endif /* __ARM_CPUERRATA_H */ diff --git a/xen/include/asm-arm/cpufeature.h b/xen/include/asm-arm/cpufeature.h index be2414c..fb57295 100644 --- a/xen/include/asm-arm/cpufeature.h +++ b/xen/include/asm-arm/cpufeature.h @@ -66,6 +66,12 @@ struct arm_cpu_capabilities { const char *desc; u16 capability; bool_t (*matches)(const struct arm_cpu_capabilities *); + union { + struct { /* To be used for eratum handling only */ + u32 midr_model; + u32 midr_range_min, midr_range_max; + }; + }; }; void update_cpu_capabilities(const struct arm_cpu_capabilities *caps,
After each CPU has been started, we iterate through a list of CPU errata to detect CPUs which need from hypervisor code patches. For each bug there is a function which check if that a particular CPU is affected. This needs to be done on every CPUs to cover heterogenous system properly. If a certain erratum has been detected, the capability bit will be set. In the case the erratum requires code patching, this will be triggered by the call to apply_alternatives. The code is based on the file arch/arm64/kernel/cpu_errata.c in Linux v4.6-rc3. Signed-off-by: Julien Grall <julien.grall@arm.com> --- Changes in v3: - Move update_cpu_capabilities in a separate patch - Update the commit message to mention that workaround may not require code patching. Changes in v2: - Use XENLOG_INFO for the loglevel of the message --- xen/arch/arm/Makefile | 1 + xen/arch/arm/cpuerrata.c | 26 ++++++++++++++++++++++++++ xen/arch/arm/setup.c | 3 +++ xen/arch/arm/smpboot.c | 3 +++ xen/include/asm-arm/cpuerrata.h | 6 ++++++ xen/include/asm-arm/cpufeature.h | 6 ++++++ 6 files changed, 45 insertions(+) create mode 100644 xen/arch/arm/cpuerrata.c create mode 100644 xen/include/asm-arm/cpuerrata.h