Re: [PATCH V6 0/5] ECAM quirks handling for ARM64 platforms

[Christopher Covington]

On 09/22/2016 07:08 PM, Bjorn Helgaas wrote:
> On Wed, Sep 21, 2016 at 06:40:47PM -0400, Christopher Covington wrote:
>> Hi Bjorn,
>>
>> On 09/21/2016 09:11 AM, Bjorn Helgaas wrote:
>>> On Tue, Sep 20, 2016 at 09:15:14PM -0400, cov@xxxxxxxxxxxxxx wrote:
>>
>>>>> diff --git a/drivers/acpi/pci_mcfg.c b/drivers/acpi/pci_mcfg.c
>>>>> index eb14f74..bb3b8ad 100644
>>>>> --- a/drivers/acpi/pci_mcfg.c
>>>>> +++ b/drivers/acpi/pci_mcfg.c
>>>>> @@ -42,86 +42,59 @@ struct mcfg_fixup {
>>>>> 	struct resource cfgres;
>>>>> };
>>>>>
>>>>> -#define MCFG_DOM_ANY			(-1)
>>>>
>>>> Did you delete this because there were no current users, because you'd
>>>> prefer users just use "-1", or for some other reason?
>>>
>>> I removed it because there were no users of it and, more importantly,
>>> the code doesn't implement support for it.
>>
>> It looks like a stale "First match against PCI topology <domain:bus>..."
>> comment remains.
> 
> Yep.  I removed the comment since it's sort of obvious from the code.
> I also renamed a few things and pulled the match out into a helper
> function.
> 
> I also changed the dmesg note: I think the actual resource and the
> name of the pci_ecam_ops is more interesting than the table IDs (which
> I think are already elsewhere in the dmesg log).

It looks like the resource is already being printed from
drivers/pci/ecam.c:102.

> Here's the incremental diff, which I can't really test:

Here's what it looks like for me:

ACPI: PCI Root Bridge [PCI2] (domain 0002 [bus 00-1f])
acpi PNP0A08:02: _OSC: OS supports [ExtendedConfig ASPM ClockPM Segments MSI]
acpi PNP0A08:02: _OSC: platform does not support [PCIeHotplug]
acpi PNP0A08:02: _OSC: OS now controls [PME AER PCIeCapability]
acpi PNP0A08:02: MCFG quirk: ECAM space for [bus 00-1f] at [mem 0xa0000000000-0xa0001ffffff] with pci_3
acpi PNP0A08:02: ECAM at [mem 0xa0000000000-0xa0001ffffff] for [bus 00-1f]
Remapped I/O 0x00000affffff0000 to [io  0x10000-0x1ffff window]
PCI host bridge to bus 0002:00

> diff --git a/drivers/acpi/pci_mcfg.c b/drivers/acpi/pci_mcfg.c
> index 245b79f..0b36bc5 100644
> --- a/drivers/acpi/pci_mcfg.c
> +++ b/drivers/acpi/pci_mcfg.c
> @@ -36,7 +36,7 @@ struct mcfg_fixup {
>  	char oem_id[ACPI_OEM_ID_SIZE + 1];
>  	char oem_table_id[ACPI_OEM_TABLE_ID_SIZE + 1];
>  	u32 oem_revision;
> -	u16 seg;
> +	u16 segment;
>  	struct resource bus_range;
>  	struct pci_ecam_ops *ops;
>  	struct resource cfgres;
> @@ -102,30 +102,37 @@ static char mcfg_oem_id[ACPI_OEM_ID_SIZE];
>  static char mcfg_oem_table_id[ACPI_OEM_TABLE_ID_SIZE];
>  static u32 mcfg_oem_revision;
>  
> -static void pci_mcfg_match_quirks(struct acpi_pci_root *root,
> +static int pci_mcfg_quirk_matches(struct mcfg_fixup *f, u16 segment,
> +				  struct resource *bus_range)
> +{
> +	if (!memcmp(f->oem_id, mcfg_oem_id, ACPI_OEM_ID_SIZE) &&
> +	    !memcmp(f->oem_table_id, mcfg_oem_table_id,
> +	            ACPI_OEM_TABLE_ID_SIZE) &&
> +	    f->oem_revision == mcfg_oem_revision &&
> +	    f->segment == segment &&
> +	    resource_contains(&f->bus_range, bus_range))
> +		return 1;
> +
> +	return 0;
> +}
> +
> +static void pci_mcfg_apply_quirks(struct acpi_pci_root *root,
>  				  struct resource *cfgres,
>  				  struct pci_ecam_ops **ecam_ops)
>  {
> +	u16 segment = root->segment;
> +	struct resource *bus_range = &root->secondary;
>  	struct mcfg_fixup *f;
>  	int i;
>  
> -	/*
> -	 * First match against PCI topology <domain:bus> then use OEM ID, OEM
> -	 * table ID, and OEM revision from MCFG table standard header.
> -	 */
>  	for (i = 0, f = mcfg_quirks; i < ARRAY_SIZE(mcfg_quirks); i++, f++) {
> -		if (!memcmp(f->oem_id, mcfg_oem_id, ACPI_OEM_ID_SIZE) &&
> -		    !memcmp(f->oem_table_id, mcfg_oem_table_id,
> -		            ACPI_OEM_TABLE_ID_SIZE) &&
> -		    f->oem_revision == mcfg_oem_revision &&
> -		    f->seg == root->segment &&
> -		    resource_contains(&f->bus_range, &root->secondary)) {
> +		if (pci_mcfg_quirk_matches(f, segment, bus_range)) {
>  			if (f->cfgres.start)
>  				*cfgres = f->cfgres;
>  			if (f->ops)
>  				*ecam_ops =  f->ops;
> -			dev_info(&root->device->dev, "Applying PCI MCFG quirks for %s %s rev: %d\n",
> -				 f->oem_id, f->oem_table_id, f->oem_revision);
> +			dev_info(&root->device->dev, "MCFG quirk: ECAM space for %pR at %pR with %ps\n",
> +				 bus_range, cfgres, *ecam_ops);
>  			return;
>  		}
>  	}
> @@ -173,7 +180,7 @@ skip_lookup:
>  	 * MCFG does not have it.  Invalid CFG start address means MCFG
>  	 * firmware bug or we need another quirk in array.
>  	 */
> -	pci_mcfg_match_quirks(root, &res, &ops);
> +	pci_mcfg_apply_quirks(root, &res, &ops);
>  	if (!res.start)
>  		return -ENXIO;
>  
> 


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