On 2015年02月04日 01:20, Catalin Marinas wrote:
On Mon, Feb 02, 2015 at 12:45:37PM +0000, Hanjun Guo wrote:diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c index afe10b4..b9f64ec 100644 --- a/arch/arm64/kernel/acpi.c +++ b/arch/arm64/kernel/acpi.c @@ -13,6 +13,8 @@ * published by the Free Software Foundation. */ +#define pr_fmt(fmt) "ACPI: " fmt + #include <linux/acpi.h> #include <linux/bootmem.h> #include <linux/cpumask.h> @@ -49,10 +51,32 @@ void __init __acpi_unmap_table(char *map, unsigned long size) early_memunmap(map, size); } +static int __init acpi_parse_fadt(struct acpi_table_header *table) +{ + struct acpi_table_fadt *fadt = (struct acpi_table_fadt *)table; + + /* + * Revision in table header is the FADT Major revision, and there + * is a minor revision of FADT which was introduced by ACPI 5.1, + * we only deal with ACPI 5.1 or newer revision to get GIC and SMP + * boot protocol configuration data, or we will disable ACPI. + */ + if (table->revision > 5 || + (table->revision == 5 && fadt->minor_revision >= 1)) + return 0; + + pr_warn("Unsupported FADT revision %d.%d, should be 5.1+, will disable ACPI\n", + table->revision, fadt->minor_revision); + disable_acpi(); + + return -EINVAL; +} + /* * acpi_boot_table_init() called from setup_arch(), always. * 1. find RSDP and get its address, and then find XSDT * 2. extract all tables and checksums them all + * 3. check ACPI FADT revision * * We can parse ACPI boot-time tables such as MADT after * this function is called. @@ -64,8 +88,16 @@ void __init acpi_boot_table_init(void) return; /* Initialize the ACPI boot-time table parser. */ - if (acpi_table_init()) + if (acpi_table_init()) { + disable_acpi(); + return; + } + + if (acpi_table_parse(ACPI_SIG_FADT, acpi_parse_fadt)) { + /* disable ACPI if no FADT is found */ disable_acpi(); + pr_err("Can't find FADT\n"); + } }It looks fine to call disable_acpi() here but a bit weird to call it again in acpi_parse_fadt(). I guess that's because acpi_table_parse() ignores the return value of the handler() call. I think it's better to fix the core code (can be an additional patch on top of this series).
I checked all the code calling acpi_table_parse() and I found that it will be no functional change if we return the value of handler(), but I need Rafael's confirm on it. Thanks Hanjun -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
