From 4c51f3e1e8702cbd0e53159fc3d1f54c20c70574 Mon Sep 17 00:00:00 2001 From: Oliver O'Halloran Date: Wed, 22 Jul 2020 16:57:14 +1000 Subject: [PATCH] powerpc/powernv/sriov: Make single PE mode a per-BAR setting Using single PE BARs to map an SR-IOV BAR is really a choice about what strategy to use when mapping a BAR. It doesn't make much sense for this to be a global setting since a device might have one large BAR which needs to be mapped with single PE windows and another smaller BAR that can be mapped with a regular segmented window. Make the segmented vs single decision a per-BAR setting and clean up the logic that decides which mode to use. Signed-off-by: Oliver O'Halloran Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200722065715.1432738-15-oohall@gmail.com --- arch/powerpc/platforms/powernv/pci-sriov.c | 131 ++++++++++----------- arch/powerpc/platforms/powernv/pci.h | 11 +- 2 files changed, 73 insertions(+), 69 deletions(-) diff --git a/arch/powerpc/platforms/powernv/pci-sriov.c b/arch/powerpc/platforms/powernv/pci-sriov.c index 31adc36c6bf1..d73684869c49 100644 --- a/arch/powerpc/platforms/powernv/pci-sriov.c +++ b/arch/powerpc/platforms/powernv/pci-sriov.c @@ -146,21 +146,17 @@ static void pnv_pci_ioda_fixup_iov_resources(struct pci_dev *pdev) { struct pnv_phb *phb = pci_bus_to_pnvhb(pdev->bus); - const resource_size_t gate = phb->ioda.m64_segsize >> 2; struct resource *res; int i; - resource_size_t size, total_vf_bar_sz; + resource_size_t vf_bar_sz; struct pnv_iov_data *iov; - int mul, total_vfs; + int mul; iov = kzalloc(sizeof(*iov), GFP_KERNEL); if (!iov) goto disable_iov; pdev->dev.archdata.iov_data = iov; - - total_vfs = pci_sriov_get_totalvfs(pdev); mul = phb->ioda.total_pe_num; - total_vf_bar_sz = 0; for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) { res = &pdev->resource[i + PCI_IOV_RESOURCES]; @@ -172,50 +168,50 @@ static void pnv_pci_ioda_fixup_iov_resources(struct pci_dev *pdev) goto disable_iov; } - total_vf_bar_sz += pci_iov_resource_size(pdev, - i + PCI_IOV_RESOURCES); + vf_bar_sz = pci_iov_resource_size(pdev, i + PCI_IOV_RESOURCES); /* - * If bigger than quarter of M64 segment size, just round up - * power of two. + * Generally, one segmented M64 BAR maps one IOV BAR. However, + * if a VF BAR is too large we end up wasting a lot of space. + * If each VF needs more than 1/4 of the default m64 segment + * then each VF BAR should be mapped in single-PE mode to reduce + * the amount of space required. This does however limit the + * number of VFs we can support. * - * 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. + * The 1/4 limit is arbitrary and can be tweaked. */ - if (total_vf_bar_sz > gate) { - mul = roundup_pow_of_two(total_vfs); - dev_info(&pdev->dev, - "VF BAR Total IOV size %llx > %llx, roundup to %d VFs\n", - total_vf_bar_sz, gate, mul); - iov->m64_single_mode = true; - break; - } - } + if (vf_bar_sz > (phb->ioda.m64_segsize >> 2)) { + /* + * On PHB3, the minimum size alignment of M64 BAR in + * single mode is 32MB. If this VF BAR is smaller than + * 32MB, but still too large for a segmented window + * then we can't map it and need to disable SR-IOV for + * this device. + */ + if (vf_bar_sz < SZ_32M) { + pci_err(pdev, "VF BAR%d: %pR can't be mapped in single PE mode\n", + i, res); + goto disable_iov; + } - for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) { - res = &pdev->resource[i + PCI_IOV_RESOURCES]; - if (!res->flags || res->parent) + iov->m64_single_mode[i] = true; continue; + } - size = pci_iov_resource_size(pdev, i + PCI_IOV_RESOURCES); /* - * On PHB3, the minimum size alignment of M64 BAR in single - * mode is 32MB. + * This BAR can be mapped with one segmented window, so adjust + * te resource size to accommodate. */ - if (iov->m64_single_mode && (size < SZ_32M)) - goto disable_iov; + pci_dbg(pdev, " Fixing VF BAR%d: %pR to\n", i, res); + res->end = res->start + vf_bar_sz * mul - 1; + pci_dbg(pdev, " %pR\n", res); - dev_dbg(&pdev->dev, " Fixing VF BAR%d: %pR to\n", i, res); - res->end = res->start + size * mul - 1; - dev_dbg(&pdev->dev, " %pR\n", res); - dev_info(&pdev->dev, "VF BAR%d: %pR (expanded to %d VFs for PE alignment)", + pci_info(pdev, "VF BAR%d: %pR (expanded to %d VFs for PE alignment)", i, res, mul); + + iov->need_shift = true; } + iov->vfs_expanded = mul; return; @@ -259,42 +255,40 @@ void pnv_pci_ioda_fixup_iov(struct pci_dev *pdev) resource_size_t pnv_pci_iov_resource_alignment(struct pci_dev *pdev, int resno) { - struct pnv_phb *phb = pci_bus_to_pnvhb(pdev->bus); struct pnv_iov_data *iov = pnv_iov_get(pdev); resource_size_t align; + /* + * iov can be null if we have an SR-IOV device with IOV BAR that can't + * be placed in the m64 space (i.e. The BAR is 32bit or non-prefetch). + * In that case we don't allow VFs to be enabled since one of their + * BARs would not be placed in the correct PE. + */ + if (!iov) + return align; + if (!iov->vfs_expanded) + return align; + + align = pci_iov_resource_size(pdev, resno); + + /* + * If we're using single mode then we can just use the native VF BAR + * alignment. We validated that it's possible to use a single PE + * window above when we did the fixup. + */ + if (iov->m64_single_mode[resno - PCI_IOV_RESOURCES]) + return align; + /* * On PowerNV platform, IOV BAR is mapped by M64 BAR to enable the * SR-IOV. While from hardware perspective, the range mapped by M64 * BAR should be size aligned. * - * When IOV BAR is mapped with M64 BAR in Single PE mode, the extra - * powernv-specific hardware restriction is gone. But if just use the - * VF BAR size as the alignment, PF BAR / VF BAR may be allocated with - * in one segment of M64 #15, which introduces the PE conflict between - * PF and VF. Based on this, the minimum alignment of an IOV BAR is - * m64_segsize. - * * This function returns the total IOV BAR size if M64 BAR is in * Shared PE mode or just VF BAR size if not. * If the M64 BAR is in Single PE mode, return the VF BAR size or * M64 segment size if IOV BAR size is less. */ - align = pci_iov_resource_size(pdev, resno); - - /* - * iov can be null if we have an SR-IOV device with IOV BAR that can't - * be placed in the m64 space (i.e. The BAR is 32bit or non-prefetch). - * In that case we don't allow VFs to be enabled so just return the - * default alignment. - */ - if (!iov) - return align; - if (!iov->vfs_expanded) - return align; - if (iov->m64_single_mode) - return max(align, (resource_size_t)phb->ioda.m64_segsize); - return iov->vfs_expanded * align; } @@ -449,7 +443,7 @@ static int pnv_pci_vf_assign_m64(struct pci_dev *pdev, u16 num_vfs) continue; /* don't need single mode? map everything in one go! */ - if (!iov->m64_single_mode) { + if (!iov->m64_single_mode[i]) { win = pnv_pci_alloc_m64_bar(phb, iov); if (win < 0) goto m64_failed; @@ -542,6 +536,8 @@ static int pnv_pci_vf_resource_shift(struct pci_dev *dev, int offset) res = &dev->resource[i + PCI_IOV_RESOURCES]; if (!res->flags || !res->parent) continue; + if (iov->m64_single_mode[i]) + continue; /* * The actual IOV BAR range is determined by the start address @@ -573,6 +569,8 @@ static int pnv_pci_vf_resource_shift(struct pci_dev *dev, int offset) res = &dev->resource[i + PCI_IOV_RESOURCES]; if (!res->flags || !res->parent) continue; + if (iov->m64_single_mode[i]) + continue; size = pci_iov_resource_size(dev, i + PCI_IOV_RESOURCES); res2 = *res; @@ -618,8 +616,8 @@ static void pnv_pci_sriov_disable(struct pci_dev *pdev) /* Release VF PEs */ pnv_ioda_release_vf_PE(pdev); - /* Un-shift the IOV BAR resources */ - if (!iov->m64_single_mode) + /* Un-shift the IOV BARs if we need to */ + if (iov->need_shift) pnv_pci_vf_resource_shift(pdev, -base_pe); /* Release M64 windows */ @@ -736,9 +734,8 @@ static int pnv_pci_sriov_enable(struct pci_dev *pdev, u16 num_vfs) * the IOV BAR according to the PE# allocated to the VFs. * Otherwise, the PE# for the VF will conflict with others. */ - if (!iov->m64_single_mode) { - ret = pnv_pci_vf_resource_shift(pdev, - base_pe->pe_number); + if (iov->need_shift) { + ret = pnv_pci_vf_resource_shift(pdev, base_pe->pe_number); if (ret) goto shift_failed; } diff --git a/arch/powerpc/platforms/powernv/pci.h b/arch/powerpc/platforms/powernv/pci.h index 41a6f4e938e4..902e928c7c22 100644 --- a/arch/powerpc/platforms/powernv/pci.h +++ b/arch/powerpc/platforms/powernv/pci.h @@ -243,8 +243,15 @@ struct pnv_iov_data { /* pointer to the array of VF PEs. num_vfs long*/ struct pnv_ioda_pe *vf_pe_arr; - /* Did we map the VF BARs with single-PE IODA BARs? */ - bool m64_single_mode; + /* Did we map the VF BAR with single-PE IODA BARs? */ + bool m64_single_mode[PCI_SRIOV_NUM_BARS]; + + /* + * True if we're using any segmented windows. In that case we need + * shift the start of the IOV resource the segment corresponding to + * the allocated PE. + */ + bool need_shift; /* * Bit mask used to track which m64 windows are used to map the