On Wed, 25 Feb 2015 16:39:49 +0800 , Hanjun Guo hanjun.guo@linaro.org 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)
- 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 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
Acked-by: Grant Likely grant.likely@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 availableSee 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)))
- enable_acpi();
- /* Initialize the ACPI boot-time table parser. */ if (acpi_table_init()) { disable_acpi();
-- 1.9.1