On Tue, Jan 13, 2026 at 11:37:14AM +0900, Koichiro Den wrote: > Extend dw_pcie_ep_set_bar() to support inbound mappings for BAR > subranges using Address Match Mode IB iATU. > > Rename the existing BAR-match helper into dw_pcie_ep_ib_atu_bar() and > introduce dw_pcie_ep_ib_atu_addr() for Address Match Mode. When > use_submap is set, read the assigned BAR base address and program one > inbound iATU window per subrange. Validate the submap array before > programming: > - each subrange is aligned to pci->region_align > - subranges cover the whole BAR (no gaps and no overlaps) > - subranges are sorted in ascending order by offset > > Track Address Match Mode mappings and tear them down on clear_bar() and > on set_bar() error paths to avoid leaving half-programmed state or > untranslated BAR holes. > > Advertise this capability by setting subrange_mapping in the EPC > features returned from dw_pcie_ep_get_features(). This also sets > dynamic_inbound_mapping, which is a prerequisite for the subrange > mapping flow. Note that vNTB already relies on this dynamic inbound > mapping behavior. > > Signed-off-by: Koichiro Den <[email protected]> > --- > .../pci/controller/dwc/pcie-designware-ep.c | 240 +++++++++++++++++- > drivers/pci/controller/dwc/pcie-designware.h | 2 + > 2 files changed, 231 insertions(+), 11 deletions(-) > > diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c > b/drivers/pci/controller/dwc/pcie-designware-ep.c > index 1195d401df19..b2ea2c2c986f 100644 > --- a/drivers/pci/controller/dwc/pcie-designware-ep.c > +++ b/drivers/pci/controller/dwc/pcie-designware-ep.c > @@ -139,9 +139,10 @@ static int dw_pcie_ep_write_header(struct pci_epc *epc, > u8 func_no, u8 vfunc_no, > return 0; > } > > -static int dw_pcie_ep_inbound_atu(struct dw_pcie_ep *ep, u8 func_no, int > type, > - dma_addr_t parent_bus_addr, enum pci_barno > bar, > - size_t size) > +/* BAR Match Mode inbound iATU mapping */ > +static int dw_pcie_ep_ib_atu_bar(struct dw_pcie_ep *ep, u8 func_no, int type, > + dma_addr_t parent_bus_addr, enum pci_barno bar, > + size_t size) > { > int ret; > u32 free_win; > @@ -174,6 +175,208 @@ static int dw_pcie_ep_inbound_atu(struct dw_pcie_ep > *ep, u8 func_no, int type, > return 0; > } > > +/* Inbound mapping bookkeeping for Address Match Mode */ > +struct dw_pcie_ib_map { > + struct list_head list; > + enum pci_barno bar; > + u64 pci_addr; > + u64 parent_bus_addr; > + u64 size; > + u32 index; > +}; > + > +static void dw_pcie_ep_clear_ib_maps(struct dw_pcie_ep *ep, enum pci_barno > bar) > +{ > + struct dw_pcie *pci = to_dw_pcie_from_ep(ep); > + struct dw_pcie_ib_map *m, *tmp; > + struct device *dev = pci->dev; > + u32 atu_index; > + > + /* Tear down the BAR Match Mode mapping, if any. */ > + if (ep->bar_to_atu[bar]) { > + atu_index = ep->bar_to_atu[bar] - 1; > + dw_pcie_disable_atu(pci, PCIE_ATU_REGION_DIR_IB, atu_index); > + clear_bit(atu_index, ep->ib_window_map); > + ep->bar_to_atu[bar] = 0; > + } > + > + /* Tear down all Address Match Mode mappings, if any. */ > + guard(spinlock_irqsave)(&ep->ib_map_lock); > + list_for_each_entry_safe(m, tmp, &ep->ib_map_list, list) { > + if (m->bar != bar) > + continue; > + dw_pcie_disable_atu(pci, PCIE_ATU_REGION_DIR_IB, m->index); > + clear_bit(m->index, ep->ib_window_map); > + list_del(&m->list); > + devm_kfree(dev, m); > + } > +} > + > +static u64 dw_pcie_ep_read_bar_assigned(struct dw_pcie_ep *ep, u8 func_no, > + enum pci_barno bar, int flags) > +{ > + u32 reg = PCI_BASE_ADDRESS_0 + (4 * bar); > + u32 lo, hi; > + u64 addr; > + > + lo = dw_pcie_ep_readl_dbi(ep, func_no, reg); > + > + if (flags & PCI_BASE_ADDRESS_SPACE) > + return lo & PCI_BASE_ADDRESS_IO_MASK; > + > + addr = lo & PCI_BASE_ADDRESS_MEM_MASK; > + if (!(flags & PCI_BASE_ADDRESS_MEM_TYPE_64)) > + return addr; > + > + hi = dw_pcie_ep_readl_dbi(ep, func_no, reg + 4); > + return addr | ((u64)hi << 32); > +} > + > +static int dw_pcie_ep_validate_submap(struct dw_pcie_ep *ep, > + const struct pci_epf_bar_submap *submap, > + unsigned int num_submap, size_t bar_size) > +{ > + struct dw_pcie *pci = to_dw_pcie_from_ep(ep); > + u32 align = pci->region_align; > + size_t expected = 0; > + size_t size, off; > + unsigned int i; > + > + if (!align || !IS_ALIGNED(bar_size, align)) > + return -EINVAL; > + > + /* > + * The array is expected to be sorted by offset before calling this > + * helper. With sorted entries, we can enforce a strict, gapless > + * decomposition of the BAR: > + * - each entry has a non-zero size > + * - offset/size/phys_addr are aligned to pci->region_align > + * - each entry lies within the BAR range > + * - entries are contiguous (no overlaps, no holes) > + * - the entries exactly cover the whole BAR > + * > + * Note: dw_pcie_prog_inbound_atu() also checks alignment for > + * offset/phys_addr, but validating up-front avoids partially > + * programming iATU windows in vain. > + */ > + for (i = 0; i < num_submap; i++) { > + off = submap[i].offset; > + size = submap[i].size; > + > + if (!size) > + return -EINVAL; > + > + if (!IS_ALIGNED(size, align) || !IS_ALIGNED(off, align)) > + return -EINVAL; > + > + if (!IS_ALIGNED(submap[i].phys_addr, align)) > + return -EINVAL; > + > + if (off > bar_size || size > bar_size - off) > + return -EINVAL; > + > + /* Enforce contiguity (no overlaps, no holes). */ > + if (off != expected) > + return -EINVAL; > + > + expected += size; > + } > + if (expected != bar_size) > + return -EINVAL; > + > + return 0; > +} > + > +/* Address Match Mode inbound iATU mapping */ > +static int dw_pcie_ep_ib_atu_addr(struct dw_pcie_ep *ep, u8 func_no, int > type, > + const struct pci_epf_bar *epf_bar) > +{ > + const struct pci_epf_bar_submap *submap = epf_bar->submap; > + struct dw_pcie *pci = to_dw_pcie_from_ep(ep); > + enum pci_barno bar = epf_bar->barno; > + struct device *dev = pci->dev; > + u64 pci_addr, parent_bus_addr; > + struct dw_pcie_ib_map *new; > + u64 size, off, base; > + unsigned long flags; > + int free_win, ret; > + unsigned int i; > + > + if (!epf_bar->num_submap || !submap || !epf_bar->size) > + return -EINVAL; > + > + ret = dw_pcie_ep_validate_submap(ep, submap, epf_bar->num_submap, > + epf_bar->size); > + if (ret) > + return ret; > + > + base = dw_pcie_ep_read_bar_assigned(ep, func_no, bar, epf_bar->flags); > + if (!base) { > + dev_err(dev, > + "BAR%u not assigned, cannot set up sub-range > mappings\n", > + bar); > + return -EINVAL; > + } > + > + /* Tear down any existing mappings before (re)programming. */ > + dw_pcie_ep_clear_ib_maps(ep, bar); > + > + for (i = 0; i < epf_bar->num_submap; i++) { > + off = submap[i].offset; > + size = submap[i].size; > + parent_bus_addr = submap[i].phys_addr; > + > + if (off > (~0ULL) - base) { > + ret = -EINVAL; > + goto err; > + } > + > + pci_addr = base + off; > + > + new = devm_kzalloc(dev, sizeof(*new), GFP_KERNEL); > + if (!new) { > + ret = -ENOMEM; > + goto err; > + } > + > + spin_lock_irqsave(&ep->ib_map_lock, flags); > + > + free_win = find_first_zero_bit(ep->ib_window_map, > + pci->num_ib_windows); > + if (free_win >= pci->num_ib_windows) { > + spin_unlock_irqrestore(&ep->ib_map_lock, flags); > + devm_kfree(dev, new); > + ret = -ENOSPC; > + goto err; > + } > + set_bit(free_win, ep->ib_window_map); > + > + new->bar = bar; > + new->index = free_win; > + new->pci_addr = pci_addr; > + new->parent_bus_addr = parent_bus_addr; > + new->size = size; > + list_add_tail(&new->list, &ep->ib_map_list); > + > + spin_unlock_irqrestore(&ep->ib_map_lock, flags); > + > + ret = dw_pcie_prog_inbound_atu(pci, free_win, type, > + parent_bus_addr, pci_addr, size); > + if (ret) { > + spin_lock_irqsave(&ep->ib_map_lock, flags); > + list_del(&new->list); > + clear_bit(free_win, ep->ib_window_map); > + spin_unlock_irqrestore(&ep->ib_map_lock, flags); > + devm_kfree(dev, new); > + goto err; > + } > + } > + return 0; > +err: > + dw_pcie_ep_clear_ib_maps(ep, bar); > + return ret; > +} > + > static int dw_pcie_ep_outbound_atu(struct dw_pcie_ep *ep, > struct dw_pcie_ob_atu_cfg *atu) > { > @@ -204,17 +407,15 @@ static void dw_pcie_ep_clear_bar(struct pci_epc *epc, > u8 func_no, u8 vfunc_no, > struct dw_pcie_ep *ep = epc_get_drvdata(epc); > struct dw_pcie *pci = to_dw_pcie_from_ep(ep); > enum pci_barno bar = epf_bar->barno; > - u32 atu_index = ep->bar_to_atu[bar] - 1; > > - if (!ep->bar_to_atu[bar]) > + if (!ep->epf_bar[bar]) > return; > > __dw_pcie_ep_reset_bar(pci, func_no, bar, epf_bar->flags); > > - dw_pcie_disable_atu(pci, PCIE_ATU_REGION_DIR_IB, atu_index); > - clear_bit(atu_index, ep->ib_window_map); > + dw_pcie_ep_clear_ib_maps(ep, bar); > + > ep->epf_bar[bar] = NULL; > - ep->bar_to_atu[bar] = 0; > } > > static unsigned int dw_pcie_ep_get_rebar_offset(struct dw_pcie *pci, > @@ -408,8 +609,12 @@ static int dw_pcie_ep_set_bar(struct pci_epc *epc, u8 > func_no, u8 vfunc_no, > else > type = PCIE_ATU_TYPE_IO; > > - ret = dw_pcie_ep_inbound_atu(ep, func_no, type, epf_bar->phys_addr, bar, > - size); > + if (epf_bar->use_submap) > + ret = dw_pcie_ep_ib_atu_addr(ep, func_no, type, epf_bar); > + else > + ret = dw_pcie_ep_ib_atu_bar(ep, func_no, type, > + epf_bar->phys_addr, bar, size); > + > if (ret) > return ret; > > @@ -626,11 +831,22 @@ static const struct pci_epc_features* > dw_pcie_ep_get_features(struct pci_epc *epc, u8 func_no, u8 vfunc_no) > { > struct dw_pcie_ep *ep = epc_get_drvdata(epc); > + struct pci_epc_features *features; > > if (!ep->ops->get_features) > return NULL; > > - return ep->ops->get_features(ep); > + features = ep->ops->get_features(ep); > + if (!features) > + return NULL; > + > + /* All DWC-based glue drivers support dynamic inbound mapping */ > + features->dynamic_inbound_mapping = true;
I think you should create a separate patch, before this patch, that simply sets: features->dynamic_inbound_mapping = true; Since that is technically a different feature, independent of this feature, so it deserves its own patch. With that fixed, this patch looks good to me: Reviewed-by: Niklas Cassel <[email protected]> > + > + /* All DWC-based glue drivers support inbound subrange mapping */ > + features->subrange_mapping = true; > + > + return features; > } > > static const struct pci_epc_ops epc_ops = { > @@ -1120,6 +1336,8 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep) > struct device *dev = pci->dev; > > INIT_LIST_HEAD(&ep->func_list); > + INIT_LIST_HEAD(&ep->ib_map_list); > + spin_lock_init(&ep->ib_map_lock); > ep->msi_iatu_mapped = false; > ep->msi_msg_addr = 0; > ep->msi_map_size = 0; > diff --git a/drivers/pci/controller/dwc/pcie-designware.h > b/drivers/pci/controller/dwc/pcie-designware.h > index 4dda9a38d46b..969b1f32dddf 100644 > --- a/drivers/pci/controller/dwc/pcie-designware.h > +++ b/drivers/pci/controller/dwc/pcie-designware.h > @@ -479,6 +479,8 @@ struct dw_pcie_ep { > phys_addr_t *outbound_addr; > unsigned long *ib_window_map; > unsigned long *ob_window_map; > + struct list_head ib_map_list; > + spinlock_t ib_map_lock; > void __iomem *msi_mem; > phys_addr_t msi_mem_phys; > struct pci_epf_bar *epf_bar[PCI_STD_NUM_BARS]; > -- > 2.51.0 >
