| Message ID | 1453540813-15764-22-git-send-email-zhaoshenglong@huawei.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Sat, 23 Jan 2016, Shannon Zhao wrote: > From: Shannon Zhao <shannon.zhao@linaro.org> > > Define new command line parameter "acpi" to enable/disable acpi. > This implements the following policy to decide whether ACPI should be > used to boot the system: > - acpi=off: ACPI will not be used to boot the system, even if there is > no alternative available (e.g., device tree is empty) > - acpi=force: only ACPI will be used to boot the system; if that fails, > there will be no fallback to alternative methods (such as device tree) > - otherwise, ACPI will be used as a fallback if the device tree turns > out to lack a platform description; the heuristic to decide this is > whether /chosen is the only node present at depth 1 > > Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org> > --- > V4: be consistent with Linux Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> > xen/arch/arm/acpi/boot.c | 52 ++++++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 52 insertions(+) > > diff --git a/xen/arch/arm/acpi/boot.c b/xen/arch/arm/acpi/boot.c > index c9135f2..8eb6c37 100644 > --- a/xen/arch/arm/acpi/boot.c > +++ b/xen/arch/arm/acpi/boot.c > @@ -30,9 +30,11 @@ > #include <xen/errno.h> > #include <acpi/actables.h> > #include <xen/mm.h> > +#include <xen/device_tree.h> > > #include <asm/acpi.h> > #include <asm/smp.h> > +#include <asm/setup.h> > > /* Processors with enabled flag and sane MPIDR */ > static unsigned int enabled_cpus; > @@ -182,6 +184,36 @@ static int __init acpi_parse_fadt(struct acpi_table_header *table) > return -EINVAL; > } > > +static bool_t __initdata param_acpi_off; > +static bool_t __initdata param_acpi_force; > + > +static void __init parse_acpi_param(char *arg) > +{ > + if ( !arg ) > + return; > + > + /* Interpret the parameter for use within Xen. */ > + if ( !parse_bool(arg) ) > + param_acpi_off = true; > + else if ( !strcmp(arg, "force") ) /* force ACPI to be enabled */ > + param_acpi_force = true; > +} > +custom_param("acpi", parse_acpi_param); > + > +static int __init dt_scan_depth1_nodes(const void *fdt, int node, > + const char *uname, int depth, > + u32 address_cells, u32 size_cells, > + void *data) > +{ > + /* > + * Return 1 as soon as we encounter a node at depth 1 that is > + * not the /chosen node. > + */ > + if (depth == 1 && (strcmp(uname, "chosen") != 0)) > + return 1; > + return 0; > +} > + > /* > * acpi_boot_table_init() called from setup_arch(), always. > * 1. find RSDP and get its address, and then find XSDT > @@ -198,6 +230,26 @@ int __init acpi_boot_table_init(void) > { > int error; > > + /* > + * Enable ACPI instead of device tree unless > + * - ACPI has been disabled explicitly (acpi=off), or > + * - the device tree is not empty (it has more than just a /chosen node) > + * and ACPI has not been force enabled (acpi=force) > + */ > + if ( param_acpi_off || ( !param_acpi_force > + && device_tree_for_each_node(device_tree_flattened, > + dt_scan_depth1_nodes, NULL))) > + { > + disable_acpi(); > + return 0; > + } > + > + /* > + * ACPI is disabled at this point. Enable it in order to parse > + * the ACPI tables. > + */ > + enable_acpi(); > + > /* Initialize the ACPI boot-time table parser. */ > error = acpi_table_init(); > if ( error ) > -- > 2.0.4 > >
diff --git a/xen/arch/arm/acpi/boot.c b/xen/arch/arm/acpi/boot.c index c9135f2..8eb6c37 100644 --- a/xen/arch/arm/acpi/boot.c +++ b/xen/arch/arm/acpi/boot.c @@ -30,9 +30,11 @@ #include <xen/errno.h> #include <acpi/actables.h> #include <xen/mm.h> +#include <xen/device_tree.h> #include <asm/acpi.h> #include <asm/smp.h> +#include <asm/setup.h> /* Processors with enabled flag and sane MPIDR */ static unsigned int enabled_cpus; @@ -182,6 +184,36 @@ static int __init acpi_parse_fadt(struct acpi_table_header *table) return -EINVAL; } +static bool_t __initdata param_acpi_off; +static bool_t __initdata param_acpi_force; + +static void __init parse_acpi_param(char *arg) +{ + if ( !arg ) + return; + + /* Interpret the parameter for use within Xen. */ + if ( !parse_bool(arg) ) + param_acpi_off = true; + else if ( !strcmp(arg, "force") ) /* force ACPI to be enabled */ + param_acpi_force = true; +} +custom_param("acpi", parse_acpi_param); + +static int __init dt_scan_depth1_nodes(const void *fdt, int node, + const char *uname, int depth, + u32 address_cells, u32 size_cells, + void *data) +{ + /* + * Return 1 as soon as we encounter a node at depth 1 that is + * not the /chosen node. + */ + if (depth == 1 && (strcmp(uname, "chosen") != 0)) + return 1; + return 0; +} + /* * acpi_boot_table_init() called from setup_arch(), always. * 1. find RSDP and get its address, and then find XSDT @@ -198,6 +230,26 @@ int __init acpi_boot_table_init(void) { int error; + /* + * Enable ACPI instead of device tree unless + * - ACPI has been disabled explicitly (acpi=off), or + * - the device tree is not empty (it has more than just a /chosen node) + * and ACPI has not been force enabled (acpi=force) + */ + if ( param_acpi_off || ( !param_acpi_force + && device_tree_for_each_node(device_tree_flattened, + dt_scan_depth1_nodes, NULL))) + { + disable_acpi(); + return 0; + } + + /* + * ACPI is disabled at this point. Enable it in order to parse + * the ACPI tables. + */ + enable_acpi(); + /* Initialize the ACPI boot-time table parser. */ error = acpi_table_init(); if ( error )