diff options
| author | Koichiro Den <den@valinux.co.jp> | 2026-03-12 16:02:31 +0300 |
|---|---|---|
| committer | Manivannan Sadhasivam <mani@kernel.org> | 2026-03-15 19:34:28 +0300 |
| commit | f51644eb40a73677fcd0c92d8174eddde5d0be0e (patch) | |
| tree | 0b301fce349fb48416333525a9e459e753ed8618 /include | |
| parent | 27ce1d8ecb9b9ae025b9e9e199845624bc950998 (diff) | |
| download | linux-f51644eb40a73677fcd0c92d8174eddde5d0be0e.tar.xz | |
PCI: endpoint: Describe reserved subregions within BARs
Some endpoint controllers expose platform-owned, fixed register windows
within a BAR that EPF drivers must not reprogram (e.g. a BAR marked
BAR_RESERVED). Even in that case, EPF drivers may need to reference a
well-defined subset of that BAR, e.g. to reuse an integrated DMA
controller MMIO window as a doorbell target.
Introduce struct pci_epc_bar_rsvd_region and extend struct
pci_epc_bar_desc so EPC drivers can advertise such fixed subregions in a
controller-agnostic way.
No functional change for existing users.
Signed-off-by: Koichiro Den <den@valinux.co.jp>
Signed-off-by: Niklas Cassel <cassel@kernel.org>
Signed-off-by: Manivannan Sadhasivam <mani@kernel.org>
Tested-by: Manikanta Maddireddy <mmaddireddy@nvidia.com>
Tested-by: Koichiro Den <den@valinux.co.jp>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Link: https://patch.msgid.link/20260312130229.2282001-15-cassel@kernel.org
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/pci-epc.h | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/include/linux/pci-epc.h b/include/linux/pci-epc.h index 5c59f5606869..ebcdf70aa9b9 100644 --- a/include/linux/pci-epc.h +++ b/include/linux/pci-epc.h @@ -201,17 +201,45 @@ enum pci_epc_bar_type { }; /** + * enum pci_epc_bar_rsvd_region_type - type of a fixed subregion behind a BAR + * @PCI_EPC_BAR_RSVD_DMA_CTRL_MMIO: Integrated DMA controller MMIO window + * + * BARs marked BAR_RESERVED are owned by the SoC/EPC hardware and must not be + * reprogrammed by EPF drivers. Some of them still expose fixed subregions that + * EPFs may want to reference (e.g. embedded doorbell fallback). + */ +enum pci_epc_bar_rsvd_region_type { + PCI_EPC_BAR_RSVD_DMA_CTRL_MMIO = 0, +}; + +/** + * struct pci_epc_bar_rsvd_region - fixed subregion behind a BAR + * @type: reserved region type + * @offset: offset within the BAR aperture + * @size: size of the reserved region + */ +struct pci_epc_bar_rsvd_region { + enum pci_epc_bar_rsvd_region_type type; + resource_size_t offset; + resource_size_t size; +}; + +/** * struct pci_epc_bar_desc - hardware description for a BAR * @type: the type of the BAR * @fixed_size: the fixed size, only applicable if type is BAR_FIXED_MASK. * @only_64bit: if true, an EPF driver is not allowed to choose if this BAR * should be configured as 32-bit or 64-bit, the EPF driver must * configure this BAR as 64-bit. + * @nr_rsvd_regions: number of fixed subregions described for BAR_RESERVED + * @rsvd_regions: fixed subregions behind BAR_RESERVED */ struct pci_epc_bar_desc { enum pci_epc_bar_type type; u64 fixed_size; bool only_64bit; + u8 nr_rsvd_regions; + const struct pci_epc_bar_rsvd_region *rsvd_regions; }; /** |