[PATCH v2 5/9] PCI: dwc: Replace certain BAR_RESERVED with BAR_DISABLED in glue drivers
From: Niklas Cassel <cassel@kernel.org>
Date: 2026-02-25 17:04:28
Also in:
imx, linux-pci, linux-renesas-soc, linux-tegra
Subsystem:
pci driver for imx6, pci driver for renesas r-car, pci native host bridge and endpoint drivers, pci subsystem, pcie driver for socionext uniphier, the rest · Maintainers:
Richard Zhu, Lucas Stach, Marek Vasut, Yoshihiro Shimoda, Lorenzo Pieralisi, Krzysztof Wilczyński, Manivannan Sadhasivam, Bjorn Helgaas, Kunihiko Hayashi, Linus Torvalds
Most DWC based EPC glue drivers that have BARs marked as BAR_RESERVED in epc_features also call dw_pcie_ep_reset_bar() for these reserved BARs in ep->ops->init(). (The only exception is pci-keystone.c.) An EPF driver will be able to get/enable BARs that have been disabled/reset using dw_pcie_ep_reset_bar(), except if the BAR is marked as BAR_RESERVED (see pci_epc_get_next_free_bar()). Thus, all EPC drivers that have BARs marked as BAR_RESERVED in epc_features and call dw_pcie_ep_reset_bar(), should really have these BARs marked as BAR_DISABLED. If dw_pcie_ep_reset_bar() is not called by the glue driver, the BARs are kept as BAR_RESERVED. No EPC drivers outside drivers/pci/controllers/dwc mark their BARs as BAR_RESERVED, so there is nothing to do in non-DWC based EPC drivers. Tested-by: Manikanta Maddireddy <redacted> Signed-off-by: Niklas Cassel <cassel@kernel.org> --- drivers/pci/controller/dwc/pci-imx6.c | 12 ++++++------ drivers/pci/controller/dwc/pci-keystone.c | 12 ++++++++++++ drivers/pci/controller/dwc/pcie-rcar-gen4.c | 6 +++--- drivers/pci/controller/dwc/pcie-tegra194.c | 8 ++++---- drivers/pci/controller/dwc/pcie-uniphier-ep.c | 4 ++-- 5 files changed, 27 insertions(+), 15 deletions(-)
diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
index a5b8d0b71677..ec1e3557ca53 100644
--- a/drivers/pci/controller/dwc/pci-imx6.c
+++ b/drivers/pci/controller/dwc/pci-imx6.c@@ -1433,19 +1433,19 @@ static int imx_pcie_ep_raise_irq(struct dw_pcie_ep *ep, u8 func_no, static const struct pci_epc_features imx8m_pcie_epc_features = { DWC_EPC_COMMON_FEATURES, .msi_capable = true, - .bar[BAR_1] = { .type = BAR_RESERVED, }, - .bar[BAR_3] = { .type = BAR_RESERVED, }, + .bar[BAR_1] = { .type = BAR_DISABLED, }, + .bar[BAR_3] = { .type = BAR_DISABLED, }, .bar[BAR_4] = { .type = BAR_FIXED, .fixed_size = SZ_256, }, - .bar[BAR_5] = { .type = BAR_RESERVED, }, + .bar[BAR_5] = { .type = BAR_DISABLED, }, .align = SZ_64K, }; static const struct pci_epc_features imx8q_pcie_epc_features = { DWC_EPC_COMMON_FEATURES, .msi_capable = true, - .bar[BAR_1] = { .type = BAR_RESERVED, }, - .bar[BAR_3] = { .type = BAR_RESERVED, }, - .bar[BAR_5] = { .type = BAR_RESERVED, }, + .bar[BAR_1] = { .type = BAR_DISABLED, }, + .bar[BAR_3] = { .type = BAR_DISABLED, }, + .bar[BAR_5] = { .type = BAR_DISABLED, }, .align = SZ_64K, };
diff --git a/drivers/pci/controller/dwc/pci-keystone.c b/drivers/pci/controller/dwc/pci-keystone.c
index 20fa4dadb82a..278d2dba1db0 100644
--- a/drivers/pci/controller/dwc/pci-keystone.c
+++ b/drivers/pci/controller/dwc/pci-keystone.c@@ -933,6 +933,18 @@ static const struct pci_epc_features ks_pcie_am654_epc_features = { DWC_EPC_COMMON_FEATURES, .msi_capable = true, .msix_capable = true, + /* + * TODO: This driver is the only DWC glue driver that had BAR_RESERVED + * BARs, but did not call dw_pcie_ep_reset_bar() for the reserved BARs. + * + * To not change the existing behavior, these BARs were not migrated to + * BAR_DISABLED. If this driver wants the BAR_RESERVED BARs to be + * disabled, it should migrate them to BAR_DISABLED. + * + * If they actually should be enabled, then the driver must also define + * what is behind these reserved BARs, see the definition of struct + * pci_epc_bar_rsvd_region. + */ .bar[BAR_0] = { .type = BAR_RESERVED, }, .bar[BAR_1] = { .type = BAR_RESERVED, }, .bar[BAR_2] = { .type = BAR_RESIZABLE, },
diff --git a/drivers/pci/controller/dwc/pcie-rcar-gen4.c b/drivers/pci/controller/dwc/pcie-rcar-gen4.c
index a6912e85e4dd..9dd05bac22b9 100644
--- a/drivers/pci/controller/dwc/pcie-rcar-gen4.c
+++ b/drivers/pci/controller/dwc/pcie-rcar-gen4.c@@ -422,10 +422,10 @@ static int rcar_gen4_pcie_ep_raise_irq(struct dw_pcie_ep *ep, u8 func_no, static const struct pci_epc_features rcar_gen4_pcie_epc_features = { DWC_EPC_COMMON_FEATURES, .msi_capable = true, - .bar[BAR_1] = { .type = BAR_RESERVED, }, - .bar[BAR_3] = { .type = BAR_RESERVED, }, + .bar[BAR_1] = { .type = BAR_DISABLED, }, + .bar[BAR_3] = { .type = BAR_DISABLED, }, .bar[BAR_4] = { .type = BAR_FIXED, .fixed_size = 256 }, - .bar[BAR_5] = { .type = BAR_RESERVED, }, + .bar[BAR_5] = { .type = BAR_DISABLED, }, .align = SZ_1M, };
diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c
index 31aa9a494dbc..9f9453e8cd23 100644
--- a/drivers/pci/controller/dwc/pcie-tegra194.c
+++ b/drivers/pci/controller/dwc/pcie-tegra194.c@@ -1994,10 +1994,10 @@ static const struct pci_epc_features tegra_pcie_epc_features = { .bar[BAR_0] = { .type = BAR_FIXED, .fixed_size = SZ_1M, .only_64bit = true, }, .bar[BAR_1] = { .type = BAR_64BIT_UPPER, }, - .bar[BAR_2] = { .type = BAR_RESERVED, }, - .bar[BAR_3] = { .type = BAR_RESERVED, }, - .bar[BAR_4] = { .type = BAR_RESERVED, }, - .bar[BAR_5] = { .type = BAR_RESERVED, }, + .bar[BAR_2] = { .type = BAR_DISABLED, }, + .bar[BAR_3] = { .type = BAR_DISABLED, }, + .bar[BAR_4] = { .type = BAR_DISABLED, }, + .bar[BAR_5] = { .type = BAR_DISABLED, }, .align = SZ_64K, };
diff --git a/drivers/pci/controller/dwc/pcie-uniphier-ep.c b/drivers/pci/controller/dwc/pcie-uniphier-ep.c
index f873a1659592..5bde3ee682b5 100644
--- a/drivers/pci/controller/dwc/pcie-uniphier-ep.c
+++ b/drivers/pci/controller/dwc/pcie-uniphier-ep.c@@ -429,8 +429,8 @@ static const struct uniphier_pcie_ep_soc_data uniphier_pro5_data = { .bar[BAR_1] = { .type = BAR_64BIT_UPPER, }, .bar[BAR_2] = { .only_64bit = true, }, .bar[BAR_3] = { .type = BAR_64BIT_UPPER, }, - .bar[BAR_4] = { .type = BAR_RESERVED, }, - .bar[BAR_5] = { .type = BAR_RESERVED, }, + .bar[BAR_4] = { .type = BAR_DISABLED, }, + .bar[BAR_5] = { .type = BAR_DISABLED, }, }, };
--
2.53.0