[PATCH v6 2/5] PCI: dwc: Allow glue drivers to return mutable EPC features

Koichiro Den
2026-01-13T02:38:42Z

The DesignWare EP midlayer needs to advertise additional capabilities at
the DWC layer (e.g. subrange_mapping) without duplicating the same bit
in every DWC-based glue driver and without copying feature structures.

Change dw_pcie_ep_ops.get_features() to return a mutable
struct pci_epc_features * and update all DWC-based glue drivers
accordingly. The DWC midlayer can then adjust/augment the returned
features while still exposing a const struct pci_epc_features * to the
PCI EPC core.

No functional change on its own.

Suggested-by: Niklas Cassel <cassel@kernel.org>
Signed-off-by: Koichiro Den <den@valinux.co.jp>
---
drivers/pci/controller/dwc/pci-dra7xx.c | 4 +-
drivers/pci/controller/dwc/pci-imx6.c | 10 ++--
drivers/pci/controller/dwc/pci-keystone.c | 4 +-
.../pci/controller/dwc/pci-layerscape-ep.c | 2 +-
drivers/pci/controller/dwc/pcie-artpec6.c | 4 +-
.../pci/controller/dwc/pcie-designware-plat.c | 4 +-
drivers/pci/controller/dwc/pcie-designware.h | 2 +-
drivers/pci/controller/dwc/pcie-dw-rockchip.c | 8 +--
drivers/pci/controller/dwc/pcie-keembay.c | 4 +-
drivers/pci/controller/dwc/pcie-qcom-ep.c | 4 +-
drivers/pci/controller/dwc/pcie-rcar-gen4.c | 4 +-
drivers/pci/controller/dwc/pcie-stm32-ep.c | 4 +-
drivers/pci/controller/dwc/pcie-tegra194.c | 4 +-
drivers/pci/controller/dwc/pcie-uniphier-ep.c | 58 ++++++++++---------
14 files changed, 60 insertions(+), 56 deletions(-)

diff --git a/drivers/pci/controller/dwc/pci-dra7xx.c b/drivers/pci/controller/dwc/pci-dra7xx.c
index 01cfd9aeb0b8..e67f8b7b56cb 100644
--- a/drivers/pci/controller/dwc/pci-dra7xx.c
+++ b/drivers/pci/controller/dwc/pci-dra7xx.c
@@ -423,12 +423,12 @@ static int dra7xx_pcie_raise_irq(struct dw_pcie_ep *ep, u8 func_no,
return 0;
}

-static const struct pci_epc_features dra7xx_pcie_epc_features = {
+static struct pci_epc_features dra7xx_pcie_epc_features = {
.linkup_notifier = true,
.msi_capable = true,
};

-static const struct pci_epc_features*
+static struct pci_epc_features*
dra7xx_pcie_get_features(struct dw_pcie_ep *ep)
{
return &dra7xx_pcie_epc_features;
diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
index 4668fc9648bf..fe1de30b3df6 100644
--- a/drivers/pci/controller/dwc/pci-imx6.c
+++ b/drivers/pci/controller/dwc/pci-imx6.c
@@ -131,7 +131,7 @@ struct imx_pcie_drvdata {
const u32 ltssm_mask;
const u32 mode_off[IMX_PCIE_MAX_INSTANCES];
const u32 mode_mask[IMX_PCIE_MAX_INSTANCES];
- const struct pci_epc_features *epc_features;
+ struct pci_epc_features *epc_features;
int (*init_phy)(struct imx_pcie *pcie);
int (*enable_ref_clk)(struct imx_pcie *pcie, bool enable);
int (*core_reset)(struct imx_pcie *pcie, bool assert);
@@ -1386,7 +1386,7 @@ static int imx_pcie_ep_raise_irq(struct dw_pcie_ep *ep, u8 func_no,
return 0;
}

-static const struct pci_epc_features imx8m_pcie_epc_features = {
+static struct pci_epc_features imx8m_pcie_epc_features = {
.msi_capable = true,
.bar[BAR_1] = { .type = BAR_RESERVED, },
.bar[BAR_3] = { .type = BAR_RESERVED, },
@@ -1395,7 +1395,7 @@ static const struct pci_epc_features imx8m_pcie_epc_features = {
.align = SZ_64K,
};

-static const struct pci_epc_features imx8q_pcie_epc_features = {
+static struct pci_epc_features imx8q_pcie_epc_features = {
.msi_capable = true,
.bar[BAR_1] = { .type = BAR_RESERVED, },
.bar[BAR_3] = { .type = BAR_RESERVED, },
@@ -1415,13 +1415,13 @@ static const struct pci_epc_features imx8q_pcie_epc_features = {
* BAR4 | Enable | 32-bit | 1 MB | Programmable Size
* BAR5 | Enable | 32-bit | 64 KB | Programmable Size
*/
-static const struct pci_epc_features imx95_pcie_epc_features = {
+static struct pci_epc_features imx95_pcie_epc_features = {
.msi_capable = true,
.bar[BAR_1] = { .type = BAR_FIXED, .fixed_size = SZ_64K, },
.align = SZ_4K,
};

-static const struct pci_epc_features*
+static struct pci_epc_features*
imx_pcie_ep_get_features(struct dw_pcie_ep *ep)
{
struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
diff --git a/drivers/pci/controller/dwc/pci-keystone.c b/drivers/pci/controller/dwc/pci-keystone.c
index f86d9111f863..4292007a9b3a 100644
--- a/drivers/pci/controller/dwc/pci-keystone.c
+++ b/drivers/pci/controller/dwc/pci-keystone.c
@@ -929,7 +929,7 @@ static int ks_pcie_am654_raise_irq(struct dw_pcie_ep *ep, u8 func_no,
return 0;
}

-static const struct pci_epc_features ks_pcie_am654_epc_features = {
+static struct pci_epc_features ks_pcie_am654_epc_features = {
.msi_capable = true,
.msix_capable = true,
.bar[BAR_0] = { .type = BAR_RESERVED, },
@@ -941,7 +941,7 @@ static const struct pci_epc_features ks_pcie_am654_epc_features = {
.align = SZ_64K,
};

-static const struct pci_epc_features*
+static struct pci_epc_features*
ks_pcie_am654_get_features(struct dw_pcie_ep *ep)
{
return &ks_pcie_am654_epc_features;
diff --git a/drivers/pci/controller/dwc/pci-layerscape-ep.c b/drivers/pci/controller/dwc/pci-layerscape-ep.c
index a4a800699f89..8d48413050ef 100644
--- a/drivers/pci/controller/dwc/pci-layerscape-ep.c
+++ b/drivers/pci/controller/dwc/pci-layerscape-ep.c
@@ -138,7 +138,7 @@ static int ls_pcie_ep_interrupt_init(struct ls_pcie_ep *pcie,
return 0;
}

-static const struct pci_epc_features*
+static struct pci_epc_features*
ls_pcie_ep_get_features(struct dw_pcie_ep *ep)
{
struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
diff --git a/drivers/pci/controller/dwc/pcie-artpec6.c b/drivers/pci/controller/dwc/pcie-artpec6.c
index f4a136ee2daf..84111d8257f2 100644
--- a/drivers/pci/controller/dwc/pcie-artpec6.c
+++ b/drivers/pci/controller/dwc/pcie-artpec6.c
@@ -369,11 +369,11 @@ static int artpec6_pcie_raise_irq(struct dw_pcie_ep *ep, u8 func_no,
return 0;
}

-static const struct pci_epc_features artpec6_pcie_epc_features = {
+static struct pci_epc_features artpec6_pcie_epc_features = {
.msi_capable = true,
};

-static const struct pci_epc_features *
+static struct pci_epc_features *
artpec6_pcie_get_features(struct dw_pcie_ep *ep)
{
return &artpec6_pcie_epc_features;
diff --git a/drivers/pci/controller/dwc/pcie-designware-plat.c b/drivers/pci/controller/dwc/pcie-designware-plat.c
index 12f41886c65d..60ada0eb838e 100644
--- a/drivers/pci/controller/dwc/pcie-designware-plat.c
+++ b/drivers/pci/controller/dwc/pcie-designware-plat.c
@@ -60,12 +60,12 @@ static int dw_plat_pcie_ep_raise_irq(struct dw_pcie_ep *ep, u8 func_no,
return 0;
}

-static const struct pci_epc_features dw_plat_pcie_epc_features = {
+static struct pci_epc_features dw_plat_pcie_epc_features = {
.msi_capable = true,
.msix_capable = true,
};

-static const struct pci_epc_features*
+static struct pci_epc_features*
dw_plat_pcie_get_features(struct dw_pcie_ep *ep)
{
return &dw_plat_pcie_epc_features;
diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
index f87c67a7a482..4dda9a38d46b 100644
--- a/drivers/pci/controller/dwc/pcie-designware.h
+++ b/drivers/pci/controller/dwc/pcie-designware.h
@@ -449,7 +449,7 @@ struct dw_pcie_ep_ops {
void (*init)(struct dw_pcie_ep *ep);
int (*raise_irq)(struct dw_pcie_ep *ep, u8 func_no,
unsigned int type, u16 interrupt_num);
- const struct pci_epc_features* (*get_features)(struct dw_pcie_ep *ep);
+ struct pci_epc_features* (*get_features)(struct dw_pcie_ep *ep);
/*
* Provide a method to implement the different func config space
* access for different platform, if different func have different
diff --git a/drivers/pci/controller/dwc/pcie-dw-rockchip.c b/drivers/pci/controller/dwc/pcie-dw-rockchip.c
index 352f513ebf03..1f3c91368dc3 100644
--- a/drivers/pci/controller/dwc/pcie-dw-rockchip.c
+++ b/drivers/pci/controller/dwc/pcie-dw-rockchip.c
@@ -100,7 +100,7 @@ struct rockchip_pcie {

struct rockchip_pcie_of_data {
enum dw_pcie_device_mode mode;
- const struct pci_epc_features *epc_features;
+ struct pci_epc_features *epc_features;
};

static int rockchip_pcie_readl_apb(struct rockchip_pcie *rockchip, u32 reg)
@@ -383,7 +383,7 @@ static int rockchip_pcie_raise_irq(struct dw_pcie_ep *ep, u8 func_no,
return 0;
}

-static const struct pci_epc_features rockchip_pcie_epc_features_rk3568 = {
+static struct pci_epc_features rockchip_pcie_epc_features_rk3568 = {
.linkup_notifier = true,
.msi_capable = true,
.msix_capable = true,
@@ -403,7 +403,7 @@ static const struct pci_epc_features rockchip_pcie_epc_features_rk3568 = {
* default.) If the host could write to BAR4, the iATU settings (for all other
* BARs) would be overwritten, resulting in (all other BARs) no longer working.
*/
-static const struct pci_epc_features rockchip_pcie_epc_features_rk3588 = {
+static struct pci_epc_features rockchip_pcie_epc_features_rk3588 = {
.linkup_notifier = true,
.msi_capable = true,
.msix_capable = true,
@@ -416,7 +416,7 @@ static const struct pci_epc_features rockchip_pcie_epc_features_rk3588 = {
.bar[BAR_5] = { .type = BAR_RESIZABLE, },
};

-static const struct pci_epc_features *
+static struct pci_epc_features *
rockchip_pcie_get_features(struct dw_pcie_ep *ep)
{
struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
diff --git a/drivers/pci/controller/dwc/pcie-keembay.c b/drivers/pci/controller/dwc/pcie-keembay.c
index 60e74ac782af..e6de5289329f 100644
--- a/drivers/pci/controller/dwc/pcie-keembay.c
+++ b/drivers/pci/controller/dwc/pcie-keembay.c
@@ -308,7 +308,7 @@ static int keembay_pcie_ep_raise_irq(struct dw_pcie_ep *ep, u8 func_no,
}
}

-static const struct pci_epc_features keembay_pcie_epc_features = {
+static struct pci_epc_features keembay_pcie_epc_features = {
.msi_capable = true,
.msix_capable = true,
.bar[BAR_0] = { .only_64bit = true, },
@@ -320,7 +320,7 @@ static const struct pci_epc_features keembay_pcie_epc_features = {
.align = SZ_16K,
};

-static const struct pci_epc_features *
+static struct pci_epc_features *
keembay_pcie_get_features(struct dw_pcie_ep *ep)
{
return &keembay_pcie_epc_features;
diff --git a/drivers/pci/controller/dwc/pcie-qcom-ep.c b/drivers/pci/controller/dwc/pcie-qcom-ep.c
index f1bc0ac81a92..6ad033301909 100644
--- a/drivers/pci/controller/dwc/pcie-qcom-ep.c
+++ b/drivers/pci/controller/dwc/pcie-qcom-ep.c
@@ -819,7 +819,7 @@ static void qcom_pcie_ep_init_debugfs(struct qcom_pcie_ep *pcie_ep)
qcom_pcie_ep_link_transition_count);
}

-static const struct pci_epc_features qcom_pcie_epc_features = {
+static struct pci_epc_features qcom_pcie_epc_features = {
.linkup_notifier = true,
.msi_capable = true,
.align = SZ_4K,
@@ -829,7 +829,7 @@ static const struct pci_epc_features qcom_pcie_epc_features = {
.bar[BAR_3] = { .type = BAR_RESERVED, },
};

-static const struct pci_epc_features *
+static struct pci_epc_features *
qcom_pcie_epc_get_features(struct dw_pcie_ep *pci_ep)
{
return &qcom_pcie_epc_features;
diff --git a/drivers/pci/controller/dwc/pcie-rcar-gen4.c b/drivers/pci/controller/dwc/pcie-rcar-gen4.c
index 80778917d2dd..ff0c4af90eff 100644
--- a/drivers/pci/controller/dwc/pcie-rcar-gen4.c
+++ b/drivers/pci/controller/dwc/pcie-rcar-gen4.c
@@ -419,7 +419,7 @@ static int rcar_gen4_pcie_ep_raise_irq(struct dw_pcie_ep *ep, u8 func_no,
return 0;
}

-static const struct pci_epc_features rcar_gen4_pcie_epc_features = {
+static struct pci_epc_features rcar_gen4_pcie_epc_features = {
.msi_capable = true,
.bar[BAR_1] = { .type = BAR_RESERVED, },
.bar[BAR_3] = { .type = BAR_RESERVED, },
@@ -428,7 +428,7 @@ static const struct pci_epc_features rcar_gen4_pcie_epc_features = {
.align = SZ_1M,
};

-static const struct pci_epc_features*
+static struct pci_epc_features*
rcar_gen4_pcie_ep_get_features(struct dw_pcie_ep *ep)
{
return &rcar_gen4_pcie_epc_features;
diff --git a/drivers/pci/controller/dwc/pcie-stm32-ep.c b/drivers/pci/controller/dwc/pcie-stm32-ep.c
index 2cecf32d2b0f..8a892def54f5 100644
--- a/drivers/pci/controller/dwc/pcie-stm32-ep.c
+++ b/drivers/pci/controller/dwc/pcie-stm32-ep.c
@@ -69,12 +69,12 @@ static int stm32_pcie_raise_irq(struct dw_pcie_ep *ep, u8 func_no,
}
}

-static const struct pci_epc_features stm32_pcie_epc_features = {
+static struct pci_epc_features stm32_pcie_epc_features = {
.msi_capable = true,
.align = SZ_64K,
};

-static const struct pci_epc_features*
+static struct pci_epc_features*
stm32_pcie_get_features(struct dw_pcie_ep *ep)
{
return &stm32_pcie_epc_features;
diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c
index 0ddeef70726d..06f45a17e52c 100644
--- a/drivers/pci/controller/dwc/pcie-tegra194.c
+++ b/drivers/pci/controller/dwc/pcie-tegra194.c
@@ -1987,7 +1987,7 @@ static int tegra_pcie_ep_raise_irq(struct dw_pcie_ep *ep, u8 func_no,
return 0;
}

-static const struct pci_epc_features tegra_pcie_epc_features = {
+static struct pci_epc_features tegra_pcie_epc_features = {
.linkup_notifier = true,
.msi_capable = true,
.bar[BAR_0] = { .type = BAR_FIXED, .fixed_size = SZ_1M,
@@ -2000,7 +2000,7 @@ static const struct pci_epc_features tegra_pcie_epc_features = {
.align = SZ_64K,
};

-static const struct pci_epc_features*
+static struct pci_epc_features*
tegra_pcie_ep_get_features(struct dw_pcie_ep *ep)
{
return &tegra_pcie_epc_features;
diff --git a/drivers/pci/controller/dwc/pcie-uniphier-ep.c b/drivers/pci/controller/dwc/pcie-uniphier-ep.c
index d6e73811216e..ddb5ff70340c 100644
--- a/drivers/pci/controller/dwc/pcie-uniphier-ep.c
+++ b/drivers/pci/controller/dwc/pcie-uniphier-ep.c
@@ -82,7 +82,7 @@ struct uniphier_pcie_ep_soc_data {
bool has_gio;
void (*init)(struct uniphier_pcie_ep_priv *priv);
int (*wait)(struct uniphier_pcie_ep_priv *priv);
- const struct pci_epc_features features;
+ struct pci_epc_features *features;
};

#define to_uniphier_pcie(x) dev_get_drvdata((x)->dev)
@@ -273,13 +273,13 @@ static int uniphier_pcie_ep_raise_irq(struct dw_pcie_ep *ep, u8 func_no,
return 0;
}

-static const struct pci_epc_features*
+static struct pci_epc_features*
uniphier_pcie_get_features(struct dw_pcie_ep *ep)
{
struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
struct uniphier_pcie_ep_priv *priv = to_uniphier_pcie(pci);

- return &priv->data->features;
+ return priv->data->features;
}

static const struct dw_pcie_ep_ops uniphier_pcie_ep_ops = {
@@ -415,40 +415,44 @@ static int uniphier_pcie_ep_probe(struct platform_device *pdev)
return 0;
}

+static struct pci_epc_features uniphier_pro5_features = {
+ .linkup_notifier = false,
+ .msi_capable = true,
+ .msix_capable = false,
+ .align = 1 << 16,
+ .bar[BAR_0] = { .only_64bit = true, },
+ .bar[BAR_1] = { .type = BAR_RESERVED, },
+ .bar[BAR_2] = { .only_64bit = true, },
+ .bar[BAR_3] = { .type = BAR_RESERVED, },
+ .bar[BAR_4] = { .type = BAR_RESERVED, },
+ .bar[BAR_5] = { .type = BAR_RESERVED, },
+};
+
+static struct pci_epc_features uniphier_nx1_features = {
+ .linkup_notifier = false,
+ .msi_capable = true,
+ .msix_capable = false,
+ .align = 1 << 12,
+ .bar[BAR_0] = { .only_64bit = true, },
+ .bar[BAR_1] = { .type = BAR_RESERVED, },
+ .bar[BAR_2] = { .only_64bit = true, },
+ .bar[BAR_3] = { .type = BAR_RESERVED, },
+ .bar[BAR_4] = { .only_64bit = true, },
+ .bar[BAR_5] = { .type = BAR_RESERVED, },
+};
+
static const struct uniphier_pcie_ep_soc_data uniphier_pro5_data = {
.has_gio = true,
.init = uniphier_pcie_pro5_init_ep,
.wait = NULL,
- .features = {
- .linkup_notifier = false,
- .msi_capable = true,
- .msix_capable = false,
- .align = 1 << 16,
- .bar[BAR_0] = { .only_64bit = true, },
- .bar[BAR_1] = { .type = BAR_RESERVED, },
- .bar[BAR_2] = { .only_64bit = true, },
- .bar[BAR_3] = { .type = BAR_RESERVED, },
- .bar[BAR_4] = { .type = BAR_RESERVED, },
- .bar[BAR_5] = { .type = BAR_RESERVED, },
- },
+ .features = &uniphier_pro5_features,
};

static const struct uniphier_pcie_ep_soc_data uniphier_nx1_data = {
.has_gio = false,
.init = uniphier_pcie_nx1_init_ep,
.wait = uniphier_pcie_nx1_wait_ep,
- .features = {
- .linkup_notifier = false,
- .msi_capable = true,
- .msix_capable = false,
- .align = 1 << 12,
- .bar[BAR_0] = { .only_64bit = true, },
- .bar[BAR_1] = { .type = BAR_RESERVED, },
- .bar[BAR_2] = { .only_64bit = true, },
- .bar[BAR_3] = { .type = BAR_RESERVED, },
- .bar[BAR_4] = { .only_64bit = true, },
- .bar[BAR_5] = { .type = BAR_RESERVED, },
- },
+ .features = &uniphier_nx1_features,
};

static const struct of_device_id uniphier_pcie_ep_match[] = {
--
2.51.0