On Wed, 25 Feb 2015 16:39:49 +0800 , Hanjun Guo <hanjun....@linaro.org> wrote: > From: Al Stone <al.st...@linaro.org> > > 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 > > CC: Catalin Marinas <catalin.mari...@arm.com> > CC: Will Deacon <will.dea...@arm.com> > CC: Rafael J. Wysocki <r...@rjwysocki.net> > Signed-off-by: Al Stone <al.st...@linaro.org> > Signed-off-by: Graeme Gregory <graeme.greg...@linaro.org> > Signed-off-by: Hanjun Guo <hanjun....@linaro.org> > Signed-off-by: Ard Biesheuvel <ard.biesheu...@linaro.org>
Acked-by: Grant Likely <grant.lik...@linaro.org> > --- > Documentation/kernel-parameters.txt | 3 ++- > arch/arm64/include/asm/acpi.h | 7 +++++ > arch/arm64/kernel/acpi.c | 52 > +++++++++++++++++++++++++++++++++---- > 3 files changed, 56 insertions(+), 6 deletions(-) > > diff --git a/Documentation/kernel-parameters.txt > b/Documentation/kernel-parameters.txt > index bfcb1a6..d6c35a7 100644 > --- a/Documentation/kernel-parameters.txt > +++ b/Documentation/kernel-parameters.txt > @@ -165,7 +165,7 @@ multipliers 'Kilo', 'Mega', and 'Giga', equalling 2^10, > 2^20, and 2^30 > bytes respectively. Such letter suffixes can also be entirely omitted. > > > - acpi= [HW,ACPI,X86] > + acpi= [HW,ACPI,X86,ARM64] > Advanced Configuration and Power Interface > Format: { force | off | strict | noirq | rsdt } > force -- enable ACPI if default was off > @@ -175,6 +175,7 @@ bytes respectively. Such letter suffixes can also be > entirely omitted. > strictly ACPI specification compliant. > rsdt -- prefer RSDT over (default) XSDT > copy_dsdt -- copy DSDT to memory > + For ARM64, ONLY "acpi=off" or "acpi=force" are available > > See also Documentation/power/runtime_pm.txt, pci=noacpi > > diff --git a/arch/arm64/include/asm/acpi.h b/arch/arm64/include/asm/acpi.h > index 40e0924..c5a9b97 100644 > --- a/arch/arm64/include/asm/acpi.h > +++ b/arch/arm64/include/asm/acpi.h > @@ -39,6 +39,13 @@ static inline void disable_acpi(void) > acpi_noirq = 1; > } > > +static inline void enable_acpi(void) > +{ > + acpi_disabled = 0; > + acpi_pci_disabled = 0; > + acpi_noirq = 0; > +} > + > /* > * It's used from ACPI core in kdump to boot UP system with SMP kernel, > * with this check the ACPI core will not override the CPU index > diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c > index f052e7a..bdcc9fc 100644 > --- a/arch/arm64/kernel/acpi.c > +++ b/arch/arm64/kernel/acpi.c > @@ -22,15 +22,49 @@ > #include <linux/irq.h> > #include <linux/irqdomain.h> > #include <linux/memblock.h> > +#include <linux/of_fdt.h> > #include <linux/smp.h> > > -int acpi_noirq; /* skip ACPI IRQ initialization */ > -int acpi_disabled; > +int acpi_noirq = 1; /* skip ACPI IRQ initialization */ > +int acpi_disabled = 1; > EXPORT_SYMBOL(acpi_disabled); > > -int acpi_pci_disabled; /* skip ACPI PCI scan and IRQ > initialization */ > +int acpi_pci_disabled = 1; /* skip ACPI PCI scan and IRQ initialization */ > EXPORT_SYMBOL(acpi_pci_disabled); > > +static bool __initdata param_acpi_off; > +static bool __initdata param_acpi_force; > + > +static int __init parse_acpi(char *arg) > +{ > + if (!arg) > + return -EINVAL; > + > + /* "acpi=off" disables both ACPI table parsing and interpreter */ > + if (strcmp(arg, "off") == 0) > + param_acpi_off = true; > + else if (strcmp(arg, "force") == 0) /* force ACPI to be enabled */ > + param_acpi_force = true; > + else > + return -EINVAL; /* Core will print when we return error */ > + > + return 0; > +} > +early_param("acpi", parse_acpi); > + > +static int __init dt_scan_depth1_nodes(unsigned long node, > + const char *uname, int depth, > + 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_map_table() will be called before page_init(), so early_ioremap() > * or early_memremap() should be called here to for ACPI table mapping. > @@ -83,10 +117,18 @@ static int __init acpi_parse_fadt(struct > acpi_table_header *table) > */ > void __init acpi_boot_table_init(void) > { > - /* If acpi_disabled, bail out */ > - if (acpi_disabled) > + /* > + * 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 && of_scan_flat_dt(dt_scan_depth1_nodes, NULL))) > return; > > + enable_acpi(); > + > /* Initialize the ACPI boot-time table parser. */ > if (acpi_table_init()) { > disable_acpi(); > -- > 1.9.1 > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/