| Message ID | 1426077587-1561-9-git-send-email-hanjun.guo@linaro.org |
|---|---|
| State | Superseded |
| Headers | show |
On 18 March 2015 at 12:35, Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> wrote: > On Wed, Mar 11, 2015 at 12:39:34PM +0000, Hanjun Guo wrote: >> From: Al Stone <al.stone@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) > > I think this comment is stale. acpi=force enables ACPI and tries to > init the ACPI tables without even checking DT, but it does fall back to > DT if ACPI table init fails (by disabling ACPI and unflattening the > FDT). > > Am I wrong ? > No, you're right. But I would suggest that we fix the code, not the comment. I think we are all in agreement on the policy, we only need to make disable_acpi() conditional on whether acpi_param_force is set >> - 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.marinas@arm.com> >> CC: Will Deacon <will.deacon@arm.com> >> CC: Rafael J. Wysocki <rjw@rjwysocki.net> >> Acked-by: Olof Johansson <olof@lixom.net> >> Acked-by: Grant Likely <grant.likely@linaro.org> >> Tested-by: Timur Tabi <timur@codeaurora.org> >> Signed-off-by: Al Stone <al.stone@linaro.org> >> Signed-off-by: Graeme Gregory <graeme.gregory@linaro.org> >> Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org> >> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@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 7abac24..2269e30 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 param_acpi_off __initdata; >> +static bool param_acpi_force __initdata; >> + >> +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 majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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 7abac24..2269e30 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 param_acpi_off __initdata; +static bool param_acpi_force __initdata; + +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();