Re: [PATCH] acpi: handle ACPI0007 Device in acpi_early_set_pdc

[Bjorn Helgaas <bjorn.helgaas@hp.com>]

On Friday, September 17, 2010 01:21:56 am Yinghai Lu wrote:
> On 09/13/2010 10:28 AM, Bjorn Helgaas wrote:
> > On Friday, September 10, 2010 08:06:26 pm Yinghai Lu wrote:
> > 
> > I timed the original on a 64-CPU box where the namespace walk cost
> > should be relatively high, and the walk you added takes about 0.01
> > seconds.  The one already there took about 0.03 seconds, so neither
> > costs very much.
> > 
> > And I don't like the fact that the patch below changes the ACPI CA
> > and it only partly implements acpi_get_devices(), since it ignores
> > _CID and _STA.
> 
> please check this one. it still keep _STA etc.

I think you missed this line in my previous response:

> > But I do see your point, and having seen the patch
> > below, I prefer the original one-line version.

The patch below is better, because it doesn't reimplement quite
so much stuff, but it still changes the CA, and I think the end
result is still quite confusing to read.

So I still prefer the original one-line version.

Bjorn

> [PATCH -v3] acpi: Handle ACPI0007 Device in acpi_early_set_pdc
> 
> After
> | commit d8191fa4a33fdc817277da4f2b7f771ff605a41c
> | Author: Alex Chiang <achiang@hp.com>
> | Date:   Mon Feb 22 12:11:39 2010 -0700
> |
> |    ACPI: processor: driver doesn't need to evaluate _PDC
> |
> |    Now that the early _PDC evaluation path knows how to correctly
> |    evaluate _PDC on only physically present processors, there's no
> |    need for the processor driver to evaluate it later when it loads.
> |
> |    To cover the hotplug case, push _PDC evaluation down into the
> |    hotplug paths.
> 
> only cpu with Processor Statement get processed with _PDC
> 
> If bios is using Device object instead of Processor statement.
> SSDTs for Pstate/Cstate/Tstate can not be loaded dynamically.
> 
> Need to try to scan ACPI0007 in addition to Processor.
> 
> That commit is between 2.6.34-rc1 and 2.6.34-rc2, so stable tree for 2.6.34+
> need this patch.
> 
> -v2: add 47 lines instead of 1 line to walk namespace one time only.
> -v3: Let acpi_match_device_hid() call acpi_ns_get_device_callback()
> 
> Signed-off-by: Yinghai Lu <yinghai@kernel.org>
> 
> ---
>  drivers/acpi/acpica/nsxfeval.c |   41 +++++++++++++++++++++++++++++++++++++++++
>  drivers/acpi/processor_core.c  |    8 +++++---
>  include/acpi/acpixf.h          |    2 ++
>  3 files changed, 48 insertions(+), 3 deletions(-)
> 
> Index: linux-2.6/drivers/acpi/processor_core.c
> ===================================================================
> --- linux-2.6.orig/drivers/acpi/processor_core.c
> +++ linux-2.6/drivers/acpi/processor_core.c
> @@ -189,7 +189,7 @@ int acpi_get_cpuid(acpi_handle handle, i
>  EXPORT_SYMBOL_GPL(acpi_get_cpuid);
>  #endif
>  
> -static bool processor_physically_present(acpi_handle handle)
> +static bool is_processor_and_physically_present(acpi_handle handle)
>  {
>  	int cpuid, type;
>  	u32 acpi_id;
> @@ -211,6 +211,8 @@ static bool processor_physically_present
>  		acpi_id = object.processor.proc_id;
>  		break;
>  	case ACPI_TYPE_DEVICE:
> +		if (acpi_match_device_hid(handle, "ACPI0007") != AE_OK)
> +			return false;
>  		status = acpi_evaluate_integer(handle, "_UID", NULL, &tmp);
>  		if (ACPI_FAILURE(status))
>  			return false;
> @@ -334,7 +336,7 @@ EXPORT_SYMBOL_GPL(acpi_processor_set_pdc
>  static acpi_status
>  early_init_pdc(acpi_handle handle, u32 lvl, void *context, void **rv)
>  {
> -	if (processor_physically_present(handle) == false)
> +	if (is_processor_and_physically_present(handle) == false)
>  		return AE_OK;
>  
>  	acpi_processor_set_pdc(handle);
> @@ -349,7 +351,7 @@ void __init acpi_early_processor_set_pdc
>  	 */
>  	dmi_check_system(processor_idle_dmi_table);
>  
> -	acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT,
> +	acpi_walk_namespace(ACPI_TYPE_ANY, ACPI_ROOT_OBJECT,
>  			    ACPI_UINT32_MAX,
>  			    early_init_pdc, NULL, NULL, NULL);
>  }
> Index: linux-2.6/drivers/acpi/acpica/nsxfeval.c
> ===================================================================
> --- linux-2.6.orig/drivers/acpi/acpica/nsxfeval.c
> +++ linux-2.6/drivers/acpi/acpica/nsxfeval.c
> @@ -642,6 +642,47 @@ acpi_ns_get_device_callback(acpi_handle
>  	return (status);
>  }
>  
> +static acpi_status
> +acpi_match_device_hid_callback(acpi_handle obj_handle,
> +			    u32 nesting_level,
> +			    void *context, void **return_value)
> +{
> +	*return_value = (void *)0xff;
> +
> +	return AE_OK;
> +}
> +
> +/*******************************************************************************
> + *
> + * FUNCTION:    acpi_match_device_hid
> + *
> + * PARAMETERS:  handle and HID to be compared
> + *
> + * RETURN:      AE_OK mean found match one
> + *
> + * DESCRIPTION: check if device coresponding to handle has HID
> + *
> + ******************************************************************************/
> +acpi_status acpi_match_device_hid(acpi_handle obj_handle, const char *HID)
> +{
> +	struct acpi_get_devices_info info;
> +	void *return_value = NULL;
> +
> +	ACPI_FUNCTION_TRACE(acpi_match_device_hid);
> +
> +	info.hid = HID;
> +	info.context = NULL;
> +	info.user_function = acpi_match_device_hid_callback;
> +
> +	acpi_ns_get_device_callback(obj_handle, ACPI_UINT32_MAX,
> +				    &info, &return_value);
> +
> +	if (!return_value)
> +		return AE_NOT_FOUND;
> +
> +	return AE_OK;
> +}
> +
>  /*******************************************************************************
>   *
>   * FUNCTION:    acpi_get_devices
> Index: linux-2.6/include/acpi/acpixf.h
> ===================================================================
> --- linux-2.6.orig/include/acpi/acpixf.h
> +++ linux-2.6/include/acpi/acpixf.h
> @@ -160,6 +160,8 @@ acpi_walk_namespace(acpi_object_type typ
>  		    acpi_walk_callback post_order_visit,
>  		    void *context, void **return_value);
>  
> +acpi_status acpi_match_device_hid(acpi_handle obj_handle, const char *HID);
> +
>  acpi_status
>  acpi_get_devices(const char *HID,
>  		 acpi_walk_callback user_function,
>