github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-06-03 03:53:37 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

PCI: dw-rockchip: Describe RK3588 BAR4 DMA ctrl window

Browse Source 
On RK3588 PCIe3_4L in EP mode, the integrated DMA controller registers
are permanently mapped to BAR4 and must not be repurposed by EPF
drivers.

When the remote peer needs to access these registers, it must use the
fixed BAR4 window instead of creating another inbound mapping in a
different BAR. Mixing the fixed window with an additional mapping can
lead to incorrect behavior.

Advertise the DMA controller MMIO window as a reserved BAR subregion so
EPF drivers can reuse it safely.

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: Koichiro Den <den@valinux.co.jp>
Reviewed-by: Manikanta Maddireddy <mmaddireddy@nvidia.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Link: https://patch.msgid.link/20260312130229.2282001-16-cassel@kernel.org
This commit is contained in:
Koichiro Den 2026-03-12 14:02:32 +01:00 committed by Manivannan Sadhasivam
parent f51644eb40
commit 489d3abb41
1 changed files with 14 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

15
drivers/pci/controller/dwc/pcie-dw-rockchip.c
View File

@ -403,6 +403,15 @@ static const struct pci_epc_features rockchip_pcie_epc_features_rk3568 = {
.bar[BAR_5] = { .type = BAR_RESIZABLE, },
};
static const struct pci_epc_bar_rsvd_region rk3588_bar4_rsvd[] = {
{
/* DMA_CAP (BAR4: DMA Port Logic Structure) */
.type = PCI_EPC_BAR_RSVD_DMA_CTRL_MMIO,
.offset = 0x0,
.size = 0x2000,
},
};
/*
* BAR4 on rk3588 exposes the ATU Port Logic Structure to the host regardless of
* iATU settings for BAR4. This means that BAR4 cannot be used by an EPF driver,
@ -420,7 +429,11 @@ static const struct pci_epc_features rockchip_pcie_epc_features_rk3588 = {
.bar[BAR_1] = { .type = BAR_RESIZABLE, },
.bar[BAR_2] = { .type = BAR_RESIZABLE, },
.bar[BAR_3] = { .type = BAR_RESIZABLE, },
.bar[BAR_4] = { .type = BAR_RESERVED, },
.bar[BAR_4] = {
.type = BAR_RESERVED,
.nr_rsvd_regions = ARRAY_SIZE(rk3588_bar4_rsvd),
.rsvd_regions = rk3588_bar4_rsvd,
},
.bar[BAR_5] = { .type = BAR_RESIZABLE, },
};