diff options
| author | Wei Yang <weiyang@linux.vnet.ibm.com> | 2015-10-22 09:22:17 +0800 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2016-02-10 12:04:57 +1100 |
| commit | f2dd0afeea0ed0e740c4b066c76a556a8b870e58 (patch) | |
| tree | 9e455698169dce902847adbe75ff378d489bedef /arch | |
| parent | ee8222fe95e40ade9f50b852095d4626631ebbbe (diff) | |
powerpc/powernv: replace the hard coded boundary with gate
At the moment 64bit-prefetchable window can be maximum 64GB, which is
currently got from device tree. This means that in shared mode the maximum
supported VF BAR size is 64GB/256=256MB. While this size could exhaust the
whole 64bit-prefetchable window. This is a design decision to set a
boundary to 64MB of the VF BAR size. Since VF BAR size with 64MB would
occupy a quarter of the 64bit-prefetchable window, this is affordable.
This patch replaces magic limit of 64MB with "gate", which is 1/4 of the
M64 Segment Size(m64_segsize >> 2) and adds comment to explain the reason
for it.
Signed-off-by: Wei Yang <weiyang@linux.vnet.ibm.com>
Reviewed-by: Gavin Shan <gwshan@linux.vent.ibm.com>
Acked-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/powerpc/platforms/powernv/pci-ioda.c | 28 |
1 files changed, 19 insertions, 9 deletions
diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c index 4004c0a842ca..b8c01fc1a6c1 100644 --- a/arch/powerpc/platforms/powernv/pci-ioda.c +++ b/arch/powerpc/platforms/powernv/pci-ioda.c @@ -2798,8 +2798,9 @@ static void pnv_pci_init_ioda_msis(struct pnv_phb *phb) { } #ifdef CONFIG_PCI_IOV static void pnv_pci_ioda_fixup_iov_resources(struct pci_dev *pdev) { - struct pci_controller *hose; - struct pnv_phb *phb; + struct pci_controller *hose = pci_bus_to_host(pdev->bus); + struct pnv_phb *phb = hose->private_data; + const resource_size_t gate = phb->ioda.m64_segsize >> 2; struct resource *res; int i; resource_size_t size; @@ -2809,9 +2810,6 @@ static void pnv_pci_ioda_fixup_iov_resources(struct pci_dev *pdev) if (!pdev->is_physfn || pdev->is_added) return; - hose = pci_bus_to_host(pdev->bus); - phb = hose->private_data; - pdn = pci_get_pdn(pdev); pdn->vfs_expanded = 0; pdn->m64_single_mode = false; @@ -2832,10 +2830,22 @@ static void pnv_pci_ioda_fixup_iov_resources(struct pci_dev *pdev) size = pci_iov_resource_size(pdev, i + PCI_IOV_RESOURCES); - /* bigger than 64M */ - if (size > (1 << 26)) { - dev_info(&pdev->dev, "PowerNV: VF BAR%d: %pR IOV size is bigger than 64M, roundup power2\n", - i, res); + /* + * If bigger than quarter of M64 segment size, just round up + * power of two. + * + * Generally, one M64 BAR maps one IOV BAR. To avoid conflict + * with other devices, IOV BAR size is expanded to be + * (total_pe * VF_BAR_size). When VF_BAR_size is half of M64 + * segment size , the expanded size would equal to half of the + * whole M64 space size, which will exhaust the M64 Space and + * limit the system flexibility. This is a design decision to + * set the boundary to quarter of the M64 segment size. + */ + if (size > gate) { + dev_info(&pdev->dev, "PowerNV: VF BAR%d: %pR IOV size " + "is bigger than %lld, roundup power2\n", + i, res, gate); mul = roundup_pow_of_two(total_vfs); pdn->m64_single_mode = true; break; |