[PATCH v8 09/21] ARM64 / ACPI: Disable ACPI if FADT revision is less than 5.1

Catalin Marinas
2015-02-03T17:20:48Z

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).

--
Catalin