From: Alexey Kardashevskiy <aik@ozlabs•ru>
To: Gavin Shan <gwshan@linux•vnet.ibm.com>,
Wei Yang <weiyang@linux•vnet.ibm.com>
Cc: benh@kernel•crashing.org, linuxppc-dev@ozlabs•org
Subject: Re: [PATCH V2 1/6] powerpc/powernv: don't enable SRIOV when VF BAR contains non M64 BAR
Date: Thu, 6 Aug 2015 16:10:21 +1000 [thread overview]
Message-ID: <55C2FA4D.4090102@ozlabs.ru> (raw)
In-Reply-To: <20150806043557.GA28524@gwshan>
On 08/06/2015 02:35 PM, Gavin Shan wrote:
> On Wed, Aug 05, 2015 at 09:24:58AM +0800, Wei Yang wrote:
>> On PHB_IODA2, we enable SRIOV devices by mapping IOV BAR with M64 BARs. If
>> a SRIOV device's BAR is not 64-bit prefetchable, this is not assigned from
>> M64 windwo, which means M64 BAR can't work on it.
>>
>
> s/PHB_IODA2/PHB3
No, it is IODA2. OPEL does PHB3-specific bits, the host kernel just uses OPAL.
> s/windwo/window
>
>> This patch makes this explicit.
>>
>> Signed-off-by: Wei Yang <weiyang@linux•vnet.ibm.com>
>
> The idea sounds right, but there is one question as below.
>
>> ---
>> arch/powerpc/platforms/powernv/pci-ioda.c | 25 +++++++++----------------
>> 1 file changed, 9 insertions(+), 16 deletions(-)
>>
>> diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
>> index 5738d31..9b41dba 100644
>> --- a/arch/powerpc/platforms/powernv/pci-ioda.c
>> +++ b/arch/powerpc/platforms/powernv/pci-ioda.c
>> @@ -908,9 +908,6 @@ static int pnv_pci_vf_resource_shift(struct pci_dev *dev, int offset)
>> if (!res->flags || !res->parent)
>> continue;
>>
>> - if (!pnv_pci_is_mem_pref_64(res->flags))
>> - continue;
>> -
>> /*
>> * The actual IOV BAR range is determined by the start address
>> * and the actual size for num_vfs VFs BAR. This check is to
>> @@ -939,9 +936,6 @@ static int pnv_pci_vf_resource_shift(struct pci_dev *dev, int offset)
>> if (!res->flags || !res->parent)
>> continue;
>>
>> - if (!pnv_pci_is_mem_pref_64(res->flags))
>> - continue;
>> -
>> size = pci_iov_resource_size(dev, i + PCI_IOV_RESOURCES);
>> res2 = *res;
>> res->start += size * offset;
>> @@ -1221,9 +1215,6 @@ static int pnv_pci_vf_assign_m64(struct pci_dev *pdev, u16 num_vfs)
>> if (!res->flags || !res->parent)
>> continue;
>>
>> - if (!pnv_pci_is_mem_pref_64(res->flags))
>> - continue;
>> -
>> for (j = 0; j < vf_groups; j++) {
>> do {
>> win = find_next_zero_bit(&phb->ioda.m64_bar_alloc,
>> @@ -1510,6 +1501,12 @@ int pnv_pci_sriov_enable(struct pci_dev *pdev, u16 num_vfs)
>> pdn = pci_get_pdn(pdev);
>>
>> if (phb->type == PNV_PHB_IODA2) {
>> + if (!pdn->vfs_expanded) {
>> + dev_info(&pdev->dev, "don't support this SRIOV device"
>> + " with non M64 VF BAR\n");
>> + return -EBUSY;
>> + }
>> +
>
> It would be -ENOSPC since -EBUSY indicates the devices (VFs) are temparily
> unavailable. For this case, the VFs are permanently unavailable because of
> running out of space to accomodate M64 and non-M64 VF BARs.
>
> The error message could be printed with dev_warn() and it would be precise
> as below or something else you prefer:
>
> dev_warn(&pdev->dev, "SRIOV not supported because of non-M64 VF BAR\n");
Both messages are cryptic.
If it is not M64 BAR, then what is it? It is always in one of M64 BARs (in
the worst case - BAR#15?), the difference is if it is segmented or not, no?
>
>
>> /* Calculate available PE for required VFs */
>> mutex_lock(&phb->ioda.pe_alloc_mutex);
>> pdn->offset = bitmap_find_next_zero_area(
>> @@ -2774,9 +2771,10 @@ static void pnv_pci_ioda_fixup_iov_resources(struct pci_dev *pdev)
>> if (!res->flags || res->parent)
>> continue;
>> if (!pnv_pci_is_mem_pref_64(res->flags)) {
>> - dev_warn(&pdev->dev, " non M64 VF BAR%d: %pR\n",
>> + dev_warn(&pdev->dev, "Don't support SR-IOV with"
>> + " non M64 VF BAR%d: %pR. \n",
>> i, res);
>> - continue;
>> + return;
>> }
>>
>> size = pci_iov_resource_size(pdev, i + PCI_IOV_RESOURCES);
>> @@ -2795,11 +2793,6 @@ static void pnv_pci_ioda_fixup_iov_resources(struct pci_dev *pdev)
>> res = &pdev->resource[i + PCI_IOV_RESOURCES];
>> if (!res->flags || res->parent)
>> continue;
>> - if (!pnv_pci_is_mem_pref_64(res->flags)) {
>> - dev_warn(&pdev->dev, "Skipping expanding VF BAR%d: %pR\n",
>> - i, res);
>> - continue;
>> - }
>
> When any one IOV BAR on the PF is non-M64, none of the VFs can be enabled.
> Will we still allocate/assign M64 or M32 resources for the IOV BARs? If so,
> I think it can be avoided.
>
>>
>> dev_dbg(&pdev->dev, " Fixing VF BAR%d: %pR to\n", i, res);
>> size = pci_iov_resource_size(pdev, i + PCI_IOV_RESOURCES);
>> --
>> 1.7.9.5
>>
>
--
Alexey
next prev parent reply other threads:[~2015-08-06 6:10 UTC|newest]
Thread overview: 56+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-07-29 7:22 [PATCH] powerpc/powernv: use one M64 BAR in Single PE mode for one VF BAR Wei Yang
2015-07-30 1:15 ` Gavin Shan
2015-07-30 5:43 ` Wei Yang
2015-07-31 0:13 ` Gavin Shan
2015-07-31 2:01 ` Wei Yang
2015-08-05 1:24 ` [PATCH V2 0/6] Redesign SR-IOV on PowerNV Wei Yang
2015-08-05 1:24 ` [PATCH V2 1/6] powerpc/powernv: don't enable SRIOV when VF BAR contains non M64 BAR Wei Yang
2015-08-06 4:35 ` Gavin Shan
2015-08-06 6:10 ` Alexey Kardashevskiy [this message]
2015-08-06 6:57 ` Gavin Shan
2015-08-06 7:47 ` Alexey Kardashevskiy
2015-08-06 11:07 ` Gavin Shan
2015-08-06 14:13 ` Wei Yang
2015-08-07 1:24 ` Alexey Kardashevskiy
2015-08-06 14:10 ` Wei Yang
2015-08-07 1:20 ` Gavin Shan
2015-08-07 2:24 ` Wei Yang
2015-08-07 3:50 ` Gavin Shan
2015-08-07 7:14 ` Alexey Kardashevskiy
2015-08-10 1:40 ` Wei Yang
2015-08-05 1:24 ` [PATCH V2 2/6] powerpc/powernv: simplify the calculation of iov resource Wei Yang
2015-08-06 4:51 ` Gavin Shan
2015-08-06 9:00 ` Alexey Kardashevskiy
2015-08-06 9:41 ` Wei Yang
2015-08-06 10:15 ` Alexey Kardashevskiy
2015-08-07 1:36 ` Wei Yang
2015-08-06 13:49 ` Wei Yang
2015-08-07 1:08 ` Gavin Shan
2015-08-05 1:25 ` [PATCH V2 3/6] powerpc/powernv: use one M64 BAR in Single PE mode for one VF BAR Wei Yang
2015-08-06 5:20 ` Gavin Shan
2015-08-06 9:36 ` Wei Yang
2015-08-06 10:07 ` Gavin Shan
2015-08-07 1:48 ` Wei Yang
2015-08-07 8:13 ` Alexey Kardashevskiy
2015-08-06 10:04 ` Alexey Kardashevskiy
2015-08-07 2:01 ` Wei Yang
2015-08-07 8:59 ` Alexey Kardashevskiy
2015-08-10 1:48 ` Wei Yang
2015-08-05 1:25 ` [PATCH V2 4/6] powerpc/powernv: replace the hard coded boundary with gate Wei Yang
2015-08-06 5:26 ` Gavin Shan
2015-08-07 9:11 ` Alexey Kardashevskiy
2015-08-05 1:25 ` [PATCH V2 5/6] powerpc/powernv: boundary the total vf bar size instead of the individual one Wei Yang
2015-08-06 5:28 ` Gavin Shan
2015-08-06 14:03 ` Wei Yang
2015-08-07 1:23 ` Gavin Shan
2015-08-07 2:25 ` Wei Yang
2015-08-05 1:25 ` [PATCH V2 6/6] powerpc/powernv: allocate discrete PE# when using M64 BAR in Single PE mode Wei Yang
2015-08-06 5:36 ` Gavin Shan
2015-08-06 13:41 ` Wei Yang
2015-08-07 1:36 ` Gavin Shan
2015-08-07 2:33 ` Wei Yang
2015-08-07 3:43 ` Gavin Shan
2015-08-07 5:44 ` Wei Yang
2015-08-07 5:54 ` Gavin Shan
2015-08-07 6:25 ` Wei Yang
2015-08-07 10:00 ` Alexey Kardashevskiy
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