[PATCH net-next v3 0/3] Unify platform suspend/resume routines for PCI DWMAC glue

[PATCH net-next v3 0/3] Unify platform suspend/resume routines for PCI DWMAC glue

[Yao Zi]

There are currently three PCI-based DWMAC glue drivers in tree,
stmmac_pci.c, dwmac-intel.c, and dwmac-loongson.c. Both stmmac_pci.c and
dwmac-intel.c implements the same and duplicated platform suspend/resume
routines.

This series introduces a new PCI helper library, stmmac_libpci.c,
providing a pair of helpers, stmmac_pci_plat_{suspend,resume}, and
replaces the driver-specific implementation with the helpers to reduce
code duplication. The helper will also simplify the Motorcomm DWMAC glue
driver which I'm working on.

The glue driver for Intel controllers isn't covered by the series, since
its suspend routine doesn't call pci_disable_device() and thus is a
little different from the new generic helpers.

I only have Loongson hardware on hand, thus the series is only tested on
Loongson 3A5000 machine. I could confirm the controller works after
resume, and WoL works as expected. This shouldn't break stmmac_pci.c,
either, since the new helpers have the exactly same code as the old
driver-specific suspend/resume hooks.

Changed from v2
- Drop unnecessary "depends on STMMAC_ETH" from STMMAC_LIBPCI
- Enclose DWMAC_LOONGSON and STMMAC_PCI within "if STMMAC_LIBPCI",
  instead of depends on the option.
- Link to v2: https://lore.kernel.org/netdev/20251030041916.19905-1-ziyao@disroot.org/

Changed from v1
- Separate the new suspend/resume helpers into a new file,
  stmmac_libpci.c, and provide Kconfig symbol for it
- Link to v1: https://lore.kernel.org/netdev/20251028154332.59118-1-ziyao@disroot.org/

Yao Zi (3):
  net: stmmac: Add generic suspend/resume helper for PCI-based
    controllers
  net: stmmac: loongson: Use generic PCI suspend/resume routines
  net: stmmac: pci: Use generic PCI suspend/resume routines

 drivers/net/ethernet/stmicro/stmmac/Kconfig   | 13 +++++
 drivers/net/ethernet/stmicro/stmmac/Makefile  |  1 +
 .../ethernet/stmicro/stmmac/dwmac-loongson.c  | 36 ++------------
 .../ethernet/stmicro/stmmac/stmmac_libpci.c   | 48 +++++++++++++++++++
 .../ethernet/stmicro/stmmac/stmmac_libpci.h   | 12 +++++
 .../net/ethernet/stmicro/stmmac/stmmac_pci.c  | 36 ++------------
 6 files changed, 80 insertions(+), 66 deletions(-)
 create mode 100644 drivers/net/ethernet/stmicro/stmmac/stmmac_libpci.c
 create mode 100644 drivers/net/ethernet/stmicro/stmmac/stmmac_libpci.h

-- 
2.51.2

[PATCH net-next v3 1/3] net: stmmac: Add generic suspend/resume helper for PCI-based controllers

[Yao Zi]

Most glue driver for PCI-based DWMAC controllers utilize similar
platform suspend/resume routines. Add a generic implementation to reduce
duplicated code.

Signed-off-by: Yao Zi <ziyao@disroot.org>
---
 drivers/net/ethernet/stmicro/stmmac/Kconfig   |  8 ++++
 drivers/net/ethernet/stmicro/stmmac/Makefile  |  1 +
 .../ethernet/stmicro/stmmac/stmmac_libpci.c   | 48 +++++++++++++++++++
 .../ethernet/stmicro/stmmac/stmmac_libpci.h   | 12 +++++
 4 files changed, 69 insertions(+)
 create mode 100644 drivers/net/ethernet/stmicro/stmmac/stmmac_libpci.c
 create mode 100644 drivers/net/ethernet/stmicro/stmmac/stmmac_libpci.h

diff --git a/drivers/net/ethernet/stmicro/stmmac/Kconfig b/drivers/net/ethernet/stmicro/stmmac/Kconfig
index 87c5bea6c2a2..1350f16f7138 100644
--- a/drivers/net/ethernet/stmicro/stmmac/Kconfig
+++ b/drivers/net/ethernet/stmicro/stmmac/Kconfig
@@ -349,6 +349,14 @@ config DWMAC_VISCONTI
 
 endif
 
+config STMMAC_LIBPCI
+	tristate "STMMAC PCI helper library"
+	depends on PCI
+	default y
+	help
+	  This selects the PCI bus helpers for the stmmac driver. If you
+	  have a controller with PCI interface, say Y or M here.
+
 config DWMAC_INTEL
 	tristate "Intel GMAC support"
 	default X86
diff --git a/drivers/net/ethernet/stmicro/stmmac/Makefile b/drivers/net/ethernet/stmicro/stmmac/Makefile
index 1681a8a28313..7bf528731034 100644
--- a/drivers/net/ethernet/stmicro/stmmac/Makefile
+++ b/drivers/net/ethernet/stmicro/stmmac/Makefile
@@ -44,6 +44,7 @@ obj-$(CONFIG_DWMAC_VISCONTI)	+= dwmac-visconti.o
 stmmac-platform-objs:= stmmac_platform.o
 dwmac-altr-socfpga-objs := dwmac-socfpga.o
 
+obj-$(CONFIG_STMMAC_LIBPCI)	+= stmmac_libpci.o
 obj-$(CONFIG_STMMAC_PCI)	+= stmmac-pci.o
 obj-$(CONFIG_DWMAC_INTEL)	+= dwmac-intel.o
 obj-$(CONFIG_DWMAC_LOONGSON)	+= dwmac-loongson.o
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_libpci.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_libpci.c
new file mode 100644
index 000000000000..5c5dd502f79a
--- /dev/null
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_libpci.c
@@ -0,0 +1,48 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * PCI bus helpers for STMMAC driver
+ * Copyright (C) 2025 Yao Zi <ziyao@disroot.org>
+ */
+
+#include <linux/device.h>
+#include <linux/pci.h>
+
+#include "stmmac_libpci.h"
+
+int stmmac_pci_plat_suspend(struct device *dev, void *bsp_priv)
+{
+	struct pci_dev *pdev = to_pci_dev(dev);
+	int ret;
+
+	ret = pci_save_state(pdev);
+	if (ret)
+		return ret;
+
+	pci_disable_device(pdev);
+	pci_wake_from_d3(pdev, true);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(stmmac_pci_plat_suspend);
+
+int stmmac_pci_plat_resume(struct device *dev, void *bsp_priv)
+{
+	struct pci_dev *pdev = to_pci_dev(dev);
+	int ret;
+
+	pci_restore_state(pdev);
+	pci_set_power_state(pdev, PCI_D0);
+
+	ret = pci_enable_device(pdev);
+	if (ret)
+		return ret;
+
+	pci_set_master(pdev);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(stmmac_pci_plat_resume);
+
+MODULE_DESCRIPTION("STMMAC PCI helper library");
+MODULE_AUTHOR("Yao Zi <ziyao@disroot.org>");
+MODULE_LICENSE("GPL");
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_libpci.h b/drivers/net/ethernet/stmicro/stmmac/stmmac_libpci.h
new file mode 100644
index 000000000000..71553184f982
--- /dev/null
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_libpci.h
@@ -0,0 +1,12 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2025 Yao Zi <ziyao@disroot.org>
+ */
+
+#ifndef __STMMAC_LIBPCI_H__
+#define __STMMAC_LIBPCI_H__
+
+int stmmac_pci_plat_suspend(struct device *dev, void *bsp_priv);
+int stmmac_pci_plat_resume(struct device *dev, void *bsp_priv);
+
+#endif /* __STMMAC_LIBPCI_H__ */
-- 
2.51.2

Re: [PATCH net-next v3 1/3] net: stmmac: Add generic suspend/resume helper for PCI-based controllers

[Russell King (Oracle)]

On Tue, Nov 04, 2025 at 03:16:45PM +0000, Yao Zi wrote:
> Most glue driver for PCI-based DWMAC controllers utilize similar
> platform suspend/resume routines. Add a generic implementation to reduce
> duplicated code.
> 
> Signed-off-by: Yao Zi <ziyao@disroot.org>

Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>

Thanks!

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!

[PATCH net-next v3 2/3] net: stmmac: loongson: Use generic PCI suspend/resume routines

[Yao Zi]

Convert glue driver for Loongson DWMAC controller to use the generic
platform suspend/resume routines for PCI controllers, instead of
implementing its own one.

Signed-off-by: Yao Zi <ziyao@disroot.org>
---
 drivers/net/ethernet/stmicro/stmmac/Kconfig   |  4 +++
 .../ethernet/stmicro/stmmac/dwmac-loongson.c  | 36 ++-----------------
 2 files changed, 7 insertions(+), 33 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/Kconfig b/drivers/net/ethernet/stmicro/stmmac/Kconfig
index 1350f16f7138..7ec7c7630c41 100644
--- a/drivers/net/ethernet/stmicro/stmmac/Kconfig
+++ b/drivers/net/ethernet/stmicro/stmmac/Kconfig
@@ -367,6 +367,8 @@ config DWMAC_INTEL
 	  This selects the Intel platform specific bus support for the
 	  stmmac driver. This driver is used for Intel Quark/EHL/TGL.
 
+if STMMAC_LIBPCI
+
 config DWMAC_LOONGSON
 	tristate "Loongson PCI DWMAC support"
 	default MACH_LOONGSON64
@@ -376,6 +378,8 @@ config DWMAC_LOONGSON
 	  This selects the LOONGSON PCI bus support for the stmmac driver,
 	  Support for ethernet controller on Loongson-2K1000 SoC and LS7A1000 bridge.
 
+endif
+
 config STMMAC_PCI
 	tristate "STMMAC PCI bus support"
 	depends on STMMAC_ETH && PCI
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-loongson.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-loongson.c
index 2a3ac0136cdb..584dc4ff8320 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-loongson.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-loongson.c
@@ -8,6 +8,7 @@
 #include <linux/device.h>
 #include <linux/of_irq.h>
 #include "stmmac.h"
+#include "stmmac_libpci.h"
 #include "dwmac_dma.h"
 #include "dwmac1000.h"
 
@@ -525,37 +526,6 @@ static int loongson_dwmac_fix_reset(struct stmmac_priv *priv, void __iomem *ioad
 				  10000, 2000000);
 }
 
-static int loongson_dwmac_suspend(struct device *dev, void *bsp_priv)
-{
-	struct pci_dev *pdev = to_pci_dev(dev);
-	int ret;
-
-	ret = pci_save_state(pdev);
-	if (ret)
-		return ret;
-
-	pci_disable_device(pdev);
-	pci_wake_from_d3(pdev, true);
-	return 0;
-}
-
-static int loongson_dwmac_resume(struct device *dev, void *bsp_priv)
-{
-	struct pci_dev *pdev = to_pci_dev(dev);
-	int ret;
-
-	pci_restore_state(pdev);
-	pci_set_power_state(pdev, PCI_D0);
-
-	ret = pci_enable_device(pdev);
-	if (ret)
-		return ret;
-
-	pci_set_master(pdev);
-
-	return 0;
-}
-
 static int loongson_dwmac_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 {
 	struct plat_stmmacenet_data *plat;
@@ -600,8 +570,8 @@ static int loongson_dwmac_probe(struct pci_dev *pdev, const struct pci_device_id
 	plat->bsp_priv = ld;
 	plat->setup = loongson_dwmac_setup;
 	plat->fix_soc_reset = loongson_dwmac_fix_reset;
-	plat->suspend = loongson_dwmac_suspend;
-	plat->resume = loongson_dwmac_resume;
+	plat->suspend = stmmac_pci_plat_suspend;
+	plat->resume = stmmac_pci_plat_resume;
 	ld->dev = &pdev->dev;
 	ld->loongson_id = readl(res.addr + GMAC_VERSION) & 0xff;
 
-- 
2.51.2

Re: [PATCH net-next v3 2/3] net: stmmac: loongson: Use generic PCI suspend/resume routines

[Russell King (Oracle)]

On Tue, Nov 04, 2025 at 03:16:46PM +0000, Yao Zi wrote:
> --- a/drivers/net/ethernet/stmicro/stmmac/Kconfig
> +++ b/drivers/net/ethernet/stmicro/stmmac/Kconfig
> @@ -367,6 +367,8 @@ config DWMAC_INTEL
>  	  This selects the Intel platform specific bus support for the
>  	  stmmac driver. This driver is used for Intel Quark/EHL/TGL.
>  
> +if STMMAC_LIBPCI
> +
>  config DWMAC_LOONGSON
>  	tristate "Loongson PCI DWMAC support"
>  	default MACH_LOONGSON64

As the next line is:

        depends on (MACH_LOONGSON64 || COMPILE_TEST) && STMMAC_ETH && PCI

where STMMAC_LIBPCI depends on PCI, and the whole lot is surrounded by
if STMMAC_ETH ... endif, shouldn't this become:

	depends on MACH_LOONGSON64 || COMPILE_TEST

?

Otherwise, looks good, thanks.

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!

Re: [PATCH net-next v3 2/3] net: stmmac: loongson: Use generic PCI suspend/resume routines

[Yao Zi]

On Tue, Nov 04, 2025 at 05:22:53PM +0000, Russell King (Oracle) wrote:
> On Tue, Nov 04, 2025 at 03:16:46PM +0000, Yao Zi wrote:
> > --- a/drivers/net/ethernet/stmicro/stmmac/Kconfig
> > +++ b/drivers/net/ethernet/stmicro/stmmac/Kconfig
> > @@ -367,6 +367,8 @@ config DWMAC_INTEL
> >  	  This selects the Intel platform specific bus support for the
> >  	  stmmac driver. This driver is used for Intel Quark/EHL/TGL.
> >  
> > +if STMMAC_LIBPCI
> > +
> >  config DWMAC_LOONGSON
> >  	tristate "Loongson PCI DWMAC support"
> >  	default MACH_LOONGSON64
> 
> As the next line is:
> 
>         depends on (MACH_LOONGSON64 || COMPILE_TEST) && STMMAC_ETH && PCI
> 
> where STMMAC_LIBPCI depends on PCI, and the whole lot is surrounded by
> if STMMAC_ETH ... endif, shouldn't this become:
> 
> 	depends on MACH_LOONGSON64 || COMPILE_TEST
> 
> ?
> 
> Otherwise, looks good, thanks.

I was originally planning to send a separate patch to remove the
redundant depends on STMMAC_ETH, since STMMAC_SELFTESTS,
STMMAC_PLATFORM, DWMAC_INTEL have similar issues. But yes PCI could be
removed from the depends as well with this series applied, so I'm not
sure whether it's better to do the simplication for DWMAC_LOONGSON and
STMMAC_PCI while adding STMMAC_LIBPCI dependency to them, or separate a
patch with a clear topic "removing redundant depends".

I prefer a separate patch to do all the Kconfig clean-up, but am willing
to simplify the depends lines in this series, too if you consider it's
better.

By the way, if I need to send v4 of the series with your proposed
simplification, should I apply your Reviewed-by tag for PATCH 2 and 3?

Thanks,
Yao Zi

> -- 
> RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
> FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!

[PATCH net-next v3 3/3] net: stmmac: pci: Use generic PCI suspend/resume routines

[Yao Zi]

Convert STMMAC PCI glue driver to use the generic platform
suspend/resume routines for PCI controllers, instead of implementing its
own one.

Signed-off-by: Yao Zi <ziyao@disroot.org>
---
 drivers/net/ethernet/stmicro/stmmac/Kconfig   |  5 +--
 .../net/ethernet/stmicro/stmmac/stmmac_pci.c  | 36 ++-----------------
 2 files changed, 6 insertions(+), 35 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/Kconfig b/drivers/net/ethernet/stmicro/stmmac/Kconfig
index 7ec7c7630c41..59aa04e71aab 100644
--- a/drivers/net/ethernet/stmicro/stmmac/Kconfig
+++ b/drivers/net/ethernet/stmicro/stmmac/Kconfig
@@ -378,8 +378,6 @@ config DWMAC_LOONGSON
 	  This selects the LOONGSON PCI bus support for the stmmac driver,
 	  Support for ethernet controller on Loongson-2K1000 SoC and LS7A1000 bridge.
 
-endif
-
 config STMMAC_PCI
 	tristate "STMMAC PCI bus support"
 	depends on STMMAC_ETH && PCI
@@ -392,4 +390,7 @@ config STMMAC_PCI
 	  If you have a controller with this interface, say Y or M here.
 
 	  If unsure, say N.
+
+endif
+
 endif
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_pci.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_pci.c
index 94b3a3b27270..fa92be672c54 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_pci.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_pci.c
@@ -14,6 +14,7 @@
 #include <linux/dmi.h>
 
 #include "stmmac.h"
+#include "stmmac_libpci.h"
 
 struct stmmac_pci_info {
 	int (*setup)(struct pci_dev *pdev, struct plat_stmmacenet_data *plat);
@@ -139,37 +140,6 @@ static const struct stmmac_pci_info snps_gmac5_pci_info = {
 	.setup = snps_gmac5_default_data,
 };
 
-static int stmmac_pci_suspend(struct device *dev, void *bsp_priv)
-{
-	struct pci_dev *pdev = to_pci_dev(dev);
-	int ret;
-
-	ret = pci_save_state(pdev);
-	if (ret)
-		return ret;
-
-	pci_disable_device(pdev);
-	pci_wake_from_d3(pdev, true);
-	return 0;
-}
-
-static int stmmac_pci_resume(struct device *dev, void *bsp_priv)
-{
-	struct pci_dev *pdev = to_pci_dev(dev);
-	int ret;
-
-	pci_restore_state(pdev);
-	pci_set_power_state(pdev, PCI_D0);
-
-	ret = pci_enable_device(pdev);
-	if (ret)
-		return ret;
-
-	pci_set_master(pdev);
-
-	return 0;
-}
-
 /**
  * stmmac_pci_probe
  *
@@ -249,8 +219,8 @@ static int stmmac_pci_probe(struct pci_dev *pdev,
 	plat->safety_feat_cfg->prtyen = 1;
 	plat->safety_feat_cfg->tmouten = 1;
 
-	plat->suspend = stmmac_pci_suspend;
-	plat->resume = stmmac_pci_resume;
+	plat->suspend = stmmac_pci_plat_suspend;
+	plat->resume = stmmac_pci_plat_resume;
 
 	return stmmac_dvr_probe(&pdev->dev, plat, &res);
 }
-- 
2.51.2

Re: [PATCH net-next v3 3/3] net: stmmac: pci: Use generic PCI suspend/resume routines

[Russell King (Oracle)]

On Tue, Nov 04, 2025 at 03:16:47PM +0000, Yao Zi wrote:
> Convert STMMAC PCI glue driver to use the generic platform
> suspend/resume routines for PCI controllers, instead of implementing its
> own one.
> 
> Signed-off-by: Yao Zi <ziyao@disroot.org>
> ---
>  drivers/net/ethernet/stmicro/stmmac/Kconfig   |  5 +--
>  .../net/ethernet/stmicro/stmmac/stmmac_pci.c  | 36 ++-----------------
>  2 files changed, 6 insertions(+), 35 deletions(-)
> 
> diff --git a/drivers/net/ethernet/stmicro/stmmac/Kconfig b/drivers/net/ethernet/stmicro/stmmac/Kconfig
> index 7ec7c7630c41..59aa04e71aab 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/Kconfig
> +++ b/drivers/net/ethernet/stmicro/stmmac/Kconfig
> @@ -378,8 +378,6 @@ config DWMAC_LOONGSON
>  	  This selects the LOONGSON PCI bus support for the stmmac driver,
>  	  Support for ethernet controller on Loongson-2K1000 SoC and LS7A1000 bridge.
>  
> -endif
> -
>  config STMMAC_PCI
>  	tristate "STMMAC PCI bus support"
>  	depends on STMMAC_ETH && PCI

As per patch 2, this line can be removed.

Otherwise, looks good, thanks.

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!