* Juergen Gross <jgross@xxxxxxxx> wrote:
> In case the rsdp address in struct boot_params is specified don't try
> to find the table by searching, but take the address directly as set
> by the boot loader.
>
> Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
> ---
> drivers/acpi/osl.c | 8 ++++++++
> 1 file changed, 8 insertions(+)
>
> diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c
> index 3bb46cb24a99..3b25e2ad7d75 100644
> --- a/drivers/acpi/osl.c
> +++ b/drivers/acpi/osl.c
> @@ -45,6 +45,10 @@
> #include <linux/uaccess.h>
> #include <linux/io-64-nonatomic-lo-hi.h>
>
> +#ifdef CONFIG_X86
> +#include <asm/setup.h>
> +#endif
> +
> #include "internal.h"
>
> #define _COMPONENT ACPI_OS_SERVICES
> @@ -195,6 +199,10 @@ acpi_physical_address __init acpi_os_get_root_pointer(void)
> if (acpi_rsdp)
> return acpi_rsdp;
> #endif
> +#ifdef CONFIG_X86
> + if (boot_params.hdr.acpi_rsdp_addr)
> + return boot_params.hdr.acpi_rsdp_addr;
> +#endif
Argh, that's typical short sighted hackery, layering violations and general
eyesore combined into a single patch ...
Those #ifdefs are a disgrace, plus why should generic ACPI code include platform
details like boot_params.hdr/acpi_rsdp_addr? It's also not very extensible to
non-x86 - so someone will have to redo this work for ARM64 as well in the future
...
So how about doing it right:
1)
Add a __weak acpi_arch_get_root_pointer() __weak function to drivers/acpi/osl.c:
__weak acpi_physical_address acpi_arch_get_root_pointer(void)
{
return 0;
}
2)
use it in acpi_os_get_root_pointer():
...
pa = acpi_arch_get_root_pointer();
if (pa)
return pa;
...
3)
Override the default variant in x86's acpi.c via something like:
acpi_physical_address acpi_arch_get_root_pointer(void)
{
return boot_params.hdr.acpi_rsdp_addr;
}
4)
Add this to arch/x86/include/asm/acpi.h:
extern acpi_physical_address acpi_arch_get_root_pointer(void);
5)
Add #include <asm/acpi.h> to drivers/acpi/osl.c.
That looks much cleaner, has no layering violations and is infinitely more
extensible, right?
Thanks,
Ingo
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