diff options
| author | Koichiro Den <den@valinux.co.jp> | 2026-01-24 23:50:06 +0900 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2026-02-26 15:01:10 -0800 |
| commit | 9330804838ced557de1832845173bfb3764f121d (patch) | |
| tree | ca80458c18fed1e01162ac84ca8f15039a76d2d1 /drivers/pci | |
| parent | d2df5d0a7d13e846de8aa79851c832b6f8d82694 (diff) | |
PCI: endpoint: Add BAR subrange mapping support
[ Upstream commit 31fb95400451040050361e22ff480476964280f0 ]
Some endpoint platforms have only a small number of usable BARs. At the
same time, EPF drivers (e.g. vNTB) may need multiple independent inbound
regions (control/scratchpad, one or more memory windows, and optionally
MSI or other feature-related regions). Subrange mapping allows these to
share a single BAR without consuming additional BARs that may not be
available, or forcing a fragile layout by aggressively packing into a
single contiguous memory range.
Extend the PCI endpoint core to support mapping subranges within a BAR.
Add an optional 'submap' field in struct pci_epf_bar so an endpoint
function driver can request inbound mappings that fully cover the BAR.
Introduce a new EPC feature bit, subrange_mapping, and reject submap
requests from pci_epc_set_bar() unless the controller advertises both
subrange_mapping and dynamic_inbound_mapping features.
The submap array describes the complete BAR layout (no overlaps and no
gaps are allowed to avoid exposing untranslated address ranges). This
provides the generic infrastructure needed to map multiple logical
regions into a single BAR at different offsets, without assuming a
controller-specific inbound address translation mechanism.
Signed-off-by: Koichiro Den <den@valinux.co.jp>
Signed-off-by: Manivannan Sadhasivam <mani@kernel.org>
Reviewed-by: Niklas Cassel <cassel@kernel.org>
Link: https://patch.msgid.link/20260124145012.2794108-3-den@valinux.co.jp
Stable-dep-of: 72cb5ed2a5c6 ("PCI: dwc: ep: Add per-PF BAR and inbound ATU mapping support")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/pci')
| -rw-r--r-- | drivers/pci/endpoint/pci-epc-core.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/drivers/pci/endpoint/pci-epc-core.c b/drivers/pci/endpoint/pci-epc-core.c index ca7f19cc973a..068155819c57 100644 --- a/drivers/pci/endpoint/pci-epc-core.c +++ b/drivers/pci/endpoint/pci-epc-core.c @@ -596,6 +596,14 @@ int pci_epc_set_bar(struct pci_epc *epc, u8 func_no, u8 vfunc_no, if (!epc_features) return -EINVAL; + if (epf_bar->num_submap && !epf_bar->submap) + return -EINVAL; + + if (epf_bar->num_submap && + !(epc_features->dynamic_inbound_mapping && + epc_features->subrange_mapping)) + return -EINVAL; + if (epc_features->bar[bar].type == BAR_RESIZABLE && (epf_bar->size < SZ_1M || (u64)epf_bar->size > (SZ_128G * 1024))) return -EINVAL; |