[PATCH V7 06/10] powerpc/eeh: Create PE for VFs

[Wei Yang]

On Mon, Jun 01, 2015 at 06:46:45PM -0500, Bjorn Helgaas wrote:
>On Tue, May 19, 2015 at 06:50:08PM +0800, Wei Yang wrote:
>> Current EEH recovery code works with the assumption: the PE has primary
>> bus. Unfortunately, that's not true to VF PEs, which generally contains
>> one or multiple VFs (for VF group case). The patch creates PEs for VFs
>> at PCI final fixup time. Those PEs for VFs are indentified with newly
>> introduced flag EEH_PE_VF so that we handle them differently during
>> EEH recovery.
>> 
>> [gwshan: changelog and code refactoring]
>> Signed-off-by: Wei Yang <weiyang at linux.vnet.ibm.com>
>> Acked-by: Gavin Shan <gwshan at linux.vnet.ibm.com>
>> ---
>>  arch/powerpc/include/asm/eeh.h               |    1 +
>>  arch/powerpc/kernel/eeh_pe.c                 |   10 ++++++++--
>>  arch/powerpc/platforms/powernv/eeh-powernv.c |   17 +++++++++++++++++
>>  3 files changed, 26 insertions(+), 2 deletions(-)
>> 
>> diff --git a/arch/powerpc/include/asm/eeh.h b/arch/powerpc/include/asm/eeh.h
>> index 1b3614d..c1fde48 100644
>> --- a/arch/powerpc/include/asm/eeh.h
>> +++ b/arch/powerpc/include/asm/eeh.h
>> @@ -70,6 +70,7 @@ struct pci_dn;
>>  #define EEH_PE_PHB	(1 << 1)	/* PHB PE    */
>>  #define EEH_PE_DEVICE 	(1 << 2)	/* Device PE */
>>  #define EEH_PE_BUS	(1 << 3)	/* Bus PE    */
>> +#define EEH_PE_VF	(1 << 4)	/* VF PE     */
>>  
>>  #define EEH_PE_ISOLATED		(1 << 0)	/* Isolated PE		*/
>>  #define EEH_PE_RECOVERING	(1 << 1)	/* Recovering PE	*/
>> diff --git a/arch/powerpc/kernel/eeh_pe.c b/arch/powerpc/kernel/eeh_pe.c
>> index 35f0b62..260a701 100644
>> --- a/arch/powerpc/kernel/eeh_pe.c
>> +++ b/arch/powerpc/kernel/eeh_pe.c
>> @@ -299,7 +299,10 @@ static struct eeh_pe *eeh_pe_get_parent(struct eeh_dev *edev)
>>  	 * EEH device already having associated PE, but
>>  	 * the direct parent EEH device doesn't have yet.
>>  	 */
>> -	pdn = pdn ? pdn->parent : NULL;
>> +	if (edev->physfn)
>> +		pdn = pci_get_pdn(edev->physfn);
>> +	else
>> +		pdn = pdn ? pdn->parent : NULL;
>>  	while (pdn) {
>>  		/* We're poking out of PCI territory */
>>  		parent = pdn_to_eeh_dev(pdn);
>> @@ -382,7 +385,10 @@ int eeh_add_to_parent_pe(struct eeh_dev *edev)
>>  	}
>>  
>>  	/* Create a new EEH PE */
>> -	pe = eeh_pe_alloc(edev->phb, EEH_PE_DEVICE);
>> +	if (edev->physfn)
>> +		pe = eeh_pe_alloc(edev->phb, EEH_PE_VF);
>> +	else
>> +		pe = eeh_pe_alloc(edev->phb, EEH_PE_DEVICE);
>>  	if (!pe) {
>>  		pr_err("%s: out of memory!\n", __func__);
>>  		return -ENOMEM;
>> diff --git a/arch/powerpc/platforms/powernv/eeh-powernv.c b/arch/powerpc/platforms/powernv/eeh-powernv.c
>> index ce738ab..c505036 100644
>> --- a/arch/powerpc/platforms/powernv/eeh-powernv.c
>> +++ b/arch/powerpc/platforms/powernv/eeh-powernv.c
>> @@ -1520,6 +1520,23 @@ static struct eeh_ops pnv_eeh_ops = {
>>  	.restore_config		= pnv_eeh_restore_config
>>  };
>>  
>> +static void pnv_eeh_vf_final_fixup(struct pci_dev *pdev)
>> +{
>> +	struct pci_dn *pdn = pci_get_pdn(pdev);
>> +
>> +	if (!pdev->is_virtfn)
>> +		return;
>> +
>> +	/*
>> +	 * The following operations will fail if VF's sysfs files
>> +	 * aren't created or its resources aren't finalized.
>> +	 */
>
>I don't understand this comment.  "The following operations" seems to refer
>to eeh_add_device_early() and eeh_add_device_late(), and
>"VF's sysfs files being created" seems to refer to eeh_sysfs_add_device().
>
>So the comment suggests that eeh_add_device_early() and
>eeh_add_device_late() will fail because they're called before
>eeh_sysfs_add_device().  So I think you must be talking about some other
>"following operations," not eeh_add_device_early() and
>eeh_add_device_late().

Sorry for this confusion.

The comment here wants to say the eeh_sysfs_add_device() will fail if the VF's
sysfs is not created well. Or it will fail if the VF's resources are not set
properly, since we would cache the VF's BAR in eeh_add_device_late().

Gavin,

If my understanding is not correct please let me know.

>
>> +	eeh_add_device_early(pdn);
>> +	eeh_add_device_late(pdev);
>> +	eeh_sysfs_add_device(pdev);
>> +}
>> +DECLARE_PCI_FIXUP_FINAL(PCI_ANY_ID, PCI_ANY_ID, pnv_eeh_vf_final_fixup);
>
>Ugh.  This is powerpc code, but I don't like using fixups as a hook like
>this.  There is a pcibios_add_device() -- could this be done there?
>

I don't like it neither :-) But looks we can't put it in the
pcibios_add_device().

>If not, what happens after pcibios_add_device() that is required for this
>code?  Maybe we need a pcibios_bus_add_device() hook?

The pnv_eeh_vf_final_fixup() will try to create sysfs for VFs. This requires
the VF sysfs(kobj) is initialized properly. If we put these into
pcibios_add_device(), the eeh_sysfs_add_device() would fail.

Below is the call flow for your reference:

pci_device_add()
    pcibios_add_device()
    device_add()                <--- kobj initialized here

>
>> +
>>  /**
>>   * eeh_powernv_init - Register platform dependent EEH operations
>>   *
>> -- 
>> 1.7.9.5
>> 
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-- 
Richard Yang
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