[PATCH v4 0/4] Loadable Module support for PCIe Cadence and J721E

[PATCH v4 0/4] Loadable Module support for PCIe Cadence and J721E

[Siddharth Vadapalli]

Hello,

This series enables support to build the PCIe Cadence Controller drivers
and the PCI J721E Application/Wrapper/Glue driver as Loadable Kernel
Modules. The motivation for this series is that PCIe is not a necessity
for booting the SoC, due to which it doesn't have to be a built-in
module. Additionally, the defconfig doesn't enable the PCIe Cadence
Controller drivers and the PCI J721E driver, due to which PCIe is not
supported by default. Enabling the configs as of now (i.e. without this
series) will result in built-in drivers i.e. a bloated Linux Image for
everyone who doesn't have the PCIe Controller. Therefore, with this
series, after enabling support for building the drivers as loadable
modules, the driver configs can be enabled in the defconfig to build
the drivers as loadable modules, thereby enabling PCIe.

Series is based on linux-next tagged next-20250417.

v3 of this series is at:
https://lore.kernel.org/r/20250410104426.463453-1-s-vadapalli@ti.com/
Changes since v3:
- In the fourth patch of this series, the polarity for PERST# assert in
  the driver's .remove callback has been fixed based on Mani's feedback at
  https://lore.kernel.org/r/6bi5gul3sqvycmkf6cwokkvownjffaf2tkonjlefo2d7cautwx@uhfexzgz3okp/

v2 of this series is at:
https://lore.kernel.org/r/20250330083914.529222-1-s-vadapalli@ti.com/
Changes since v2:
- Collected "Reviewed-by" tag from:
  Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
  for the third patch in this series.
- Dropped a delay before PERST assertion in the driver's remove callback
  in the fourth patch of this series based on Mani's feedback at:
  https://lore.kernel.org/r/zsxnx7biwogov5dw5yiafkgk6tsrtspac75bjbrca5uevweaim@ly67hwfyk7qh/

v1 of this series is at:
https://lore.kernel.org/r/20250307103128.3287497-1-s-vadapalli@ti.com/
Changes since v1:
- Collected "Reviewed-by" tags from:
  Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
  for the first two patches in this series.
- Based on feedback from Mani on the third patch of the v1 series at:
  https://lore.kernel.org/r/20250318080304.jsmrxqil6pn74nzh@thinkpad/
  pci_epc_deinit_notify() has been included in cdns_pcie_ep_disable().
- Based on feedback from Thomas on the fourth patch of the v1 series at:
  https://lore.kernel.org/r/88b3ecbe-32b6-4310-afb9-da19a2d0506a@bootlin.com/
  the "check" for a non-NULL "pcie-refclk" in j721e_pcie_remove() has been
  dropped.

Regards,
Siddharth.

Kishon Vijay Abraham I (1):
  PCI: cadence: Add support to build pcie-cadence library as a kernel
    module

Siddharth Vadapalli (3):
  PCI: cadence-host: Introduce cdns_pcie_host_disable helper for cleanup
  PCI: cadence-ep: Introduce cdns_pcie_ep_disable helper for cleanup
  PCI: j721e: Add support to build as a loadable module

 drivers/pci/controller/cadence/Kconfig        |  12 +-
 drivers/pci/controller/cadence/pci-j721e.c    |  31 ++++-
 .../pci/controller/cadence/pcie-cadence-ep.c  |  17 +++
 .../controller/cadence/pcie-cadence-host.c    | 113 ++++++++++++++++++
 drivers/pci/controller/cadence/pcie-cadence.c |  12 ++
 drivers/pci/controller/cadence/pcie-cadence.h |  14 ++-
 6 files changed, 190 insertions(+), 9 deletions(-)

-- 
2.34.1

[PATCH v4 1/4] PCI: cadence: Add support to build pcie-cadence library as a kernel module

[Siddharth Vadapalli]

From: Kishon Vijay Abraham I <kishon@ti.com>

Currently, the Cadence PCIe controller driver can be built as a built-in
module only. Since PCIe functionality is not a necessity for booting, add
support to build the Cadence PCIe driver as a loadable module as well.

Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Siddharth Vadapalli <s-vadapalli@ti.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---

v3 patch is at:
https://lore.kernel.org/r/20250410104426.463453-2-s-vadapalli@ti.com/
No changes since v3.

Regards,
Siddharth.

 drivers/pci/controller/cadence/Kconfig             |  6 +++---
 drivers/pci/controller/cadence/pcie-cadence-ep.c   |  6 ++++++
 drivers/pci/controller/cadence/pcie-cadence-host.c |  9 +++++++++
 drivers/pci/controller/cadence/pcie-cadence.c      | 12 ++++++++++++
 drivers/pci/controller/cadence/pcie-cadence.h      |  4 ++--
 5 files changed, 32 insertions(+), 5 deletions(-)

diff --git a/drivers/pci/controller/cadence/Kconfig b/drivers/pci/controller/cadence/Kconfig
index 8a0044bb3989..82b58096eea0 100644
--- a/drivers/pci/controller/cadence/Kconfig
+++ b/drivers/pci/controller/cadence/Kconfig
@@ -4,16 +4,16 @@ menu "Cadence-based PCIe controllers"
 	depends on PCI
 
 config PCIE_CADENCE
-	bool
+	tristate
 
 config PCIE_CADENCE_HOST
-	bool
+	tristate
 	depends on OF
 	select IRQ_DOMAIN
 	select PCIE_CADENCE
 
 config PCIE_CADENCE_EP
-	bool
+	tristate
 	depends on OF
 	depends on PCI_ENDPOINT
 	select PCIE_CADENCE
diff --git a/drivers/pci/controller/cadence/pcie-cadence-ep.c b/drivers/pci/controller/cadence/pcie-cadence-ep.c
index 599ec4b1223e..b4bcef2d020a 100644
--- a/drivers/pci/controller/cadence/pcie-cadence-ep.c
+++ b/drivers/pci/controller/cadence/pcie-cadence-ep.c
@@ -6,6 +6,7 @@
 #include <linux/bitfield.h>
 #include <linux/delay.h>
 #include <linux/kernel.h>
+#include <linux/module.h>
 #include <linux/of.h>
 #include <linux/pci-epc.h>
 #include <linux/platform_device.h>
@@ -751,3 +752,8 @@ int cdns_pcie_ep_setup(struct cdns_pcie_ep *ep)
 
 	return ret;
 }
+EXPORT_SYMBOL_GPL(cdns_pcie_ep_setup);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Cadence PCIe endpoint controller driver");
+MODULE_AUTHOR("Cyrille Pitchen <cyrille.pitchen@free-electrons.com>");
diff --git a/drivers/pci/controller/cadence/pcie-cadence-host.c b/drivers/pci/controller/cadence/pcie-cadence-host.c
index 8af95e9da7ce..96055edeb099 100644
--- a/drivers/pci/controller/cadence/pcie-cadence-host.c
+++ b/drivers/pci/controller/cadence/pcie-cadence-host.c
@@ -5,6 +5,7 @@
 
 #include <linux/delay.h>
 #include <linux/kernel.h>
+#include <linux/module.h>
 #include <linux/list_sort.h>
 #include <linux/of_address.h>
 #include <linux/of_pci.h>
@@ -72,6 +73,7 @@ void __iomem *cdns_pci_map_bus(struct pci_bus *bus, unsigned int devfn,
 
 	return rc->cfg_base + (where & 0xfff);
 }
+EXPORT_SYMBOL_GPL(cdns_pci_map_bus);
 
 static struct pci_ops cdns_pcie_host_ops = {
 	.map_bus	= cdns_pci_map_bus,
@@ -495,6 +497,7 @@ int cdns_pcie_host_init(struct cdns_pcie_rc *rc)
 
 	return cdns_pcie_host_init_address_translation(rc);
 }
+EXPORT_SYMBOL_GPL(cdns_pcie_host_init);
 
 int cdns_pcie_host_link_setup(struct cdns_pcie_rc *rc)
 {
@@ -519,6 +522,7 @@ int cdns_pcie_host_link_setup(struct cdns_pcie_rc *rc)
 
 	return 0;
 }
+EXPORT_SYMBOL_GPL(cdns_pcie_host_link_setup);
 
 int cdns_pcie_host_setup(struct cdns_pcie_rc *rc)
 {
@@ -581,3 +585,8 @@ int cdns_pcie_host_setup(struct cdns_pcie_rc *rc)
 
 	return ret;
 }
+EXPORT_SYMBOL_GPL(cdns_pcie_host_setup);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Cadence PCIe host controller driver");
+MODULE_AUTHOR("Cyrille Pitchen <cyrille.pitchen@free-electrons.com>");
diff --git a/drivers/pci/controller/cadence/pcie-cadence.c b/drivers/pci/controller/cadence/pcie-cadence.c
index 204e045aed8c..70a19573440e 100644
--- a/drivers/pci/controller/cadence/pcie-cadence.c
+++ b/drivers/pci/controller/cadence/pcie-cadence.c
@@ -4,6 +4,7 @@
 // Author: Cyrille Pitchen <cyrille.pitchen@free-electrons.com>
 
 #include <linux/kernel.h>
+#include <linux/module.h>
 #include <linux/of.h>
 
 #include "pcie-cadence.h"
@@ -23,6 +24,7 @@ void cdns_pcie_detect_quiet_min_delay_set(struct cdns_pcie *pcie)
 
 	cdns_pcie_writel(pcie, CDNS_PCIE_LTSSM_CONTROL_CAP, ltssm_control_cap);
 }
+EXPORT_SYMBOL_GPL(cdns_pcie_detect_quiet_min_delay_set);
 
 void cdns_pcie_set_outbound_region(struct cdns_pcie *pcie, u8 busnr, u8 fn,
 				   u32 r, bool is_io,
@@ -100,6 +102,7 @@ void cdns_pcie_set_outbound_region(struct cdns_pcie *pcie, u8 busnr, u8 fn,
 	cdns_pcie_writel(pcie, CDNS_PCIE_AT_OB_REGION_CPU_ADDR0(r), addr0);
 	cdns_pcie_writel(pcie, CDNS_PCIE_AT_OB_REGION_CPU_ADDR1(r), addr1);
 }
+EXPORT_SYMBOL_GPL(cdns_pcie_set_outbound_region);
 
 void cdns_pcie_set_outbound_region_for_normal_msg(struct cdns_pcie *pcie,
 						  u8 busnr, u8 fn,
@@ -134,6 +137,7 @@ void cdns_pcie_set_outbound_region_for_normal_msg(struct cdns_pcie *pcie,
 	cdns_pcie_writel(pcie, CDNS_PCIE_AT_OB_REGION_CPU_ADDR0(r), addr0);
 	cdns_pcie_writel(pcie, CDNS_PCIE_AT_OB_REGION_CPU_ADDR1(r), addr1);
 }
+EXPORT_SYMBOL_GPL(cdns_pcie_set_outbound_region_for_normal_msg);
 
 void cdns_pcie_reset_outbound_region(struct cdns_pcie *pcie, u32 r)
 {
@@ -146,6 +150,7 @@ void cdns_pcie_reset_outbound_region(struct cdns_pcie *pcie, u32 r)
 	cdns_pcie_writel(pcie, CDNS_PCIE_AT_OB_REGION_CPU_ADDR0(r), 0);
 	cdns_pcie_writel(pcie, CDNS_PCIE_AT_OB_REGION_CPU_ADDR1(r), 0);
 }
+EXPORT_SYMBOL_GPL(cdns_pcie_reset_outbound_region);
 
 void cdns_pcie_disable_phy(struct cdns_pcie *pcie)
 {
@@ -156,6 +161,7 @@ void cdns_pcie_disable_phy(struct cdns_pcie *pcie)
 		phy_exit(pcie->phy[i]);
 	}
 }
+EXPORT_SYMBOL_GPL(cdns_pcie_disable_phy);
 
 int cdns_pcie_enable_phy(struct cdns_pcie *pcie)
 {
@@ -184,6 +190,7 @@ int cdns_pcie_enable_phy(struct cdns_pcie *pcie)
 
 	return ret;
 }
+EXPORT_SYMBOL_GPL(cdns_pcie_enable_phy);
 
 int cdns_pcie_init_phy(struct device *dev, struct cdns_pcie *pcie)
 {
@@ -243,6 +250,7 @@ int cdns_pcie_init_phy(struct device *dev, struct cdns_pcie *pcie)
 
 	return ret;
 }
+EXPORT_SYMBOL_GPL(cdns_pcie_init_phy);
 
 static int cdns_pcie_suspend_noirq(struct device *dev)
 {
@@ -271,3 +279,7 @@ const struct dev_pm_ops cdns_pcie_pm_ops = {
 	NOIRQ_SYSTEM_SLEEP_PM_OPS(cdns_pcie_suspend_noirq,
 				  cdns_pcie_resume_noirq)
 };
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Cadence PCIe controller driver");
+MODULE_AUTHOR("Cyrille Pitchen <cyrille.pitchen@free-electrons.com>");
diff --git a/drivers/pci/controller/cadence/pcie-cadence.h b/drivers/pci/controller/cadence/pcie-cadence.h
index 39ee9945c903..4b7f295e24e7 100644
--- a/drivers/pci/controller/cadence/pcie-cadence.h
+++ b/drivers/pci/controller/cadence/pcie-cadence.h
@@ -519,7 +519,7 @@ static inline bool cdns_pcie_link_up(struct cdns_pcie *pcie)
 	return true;
 }
 
-#ifdef CONFIG_PCIE_CADENCE_HOST
+#if IS_ENABLED(CONFIG_PCIE_CADENCE_HOST)
 int cdns_pcie_host_link_setup(struct cdns_pcie_rc *rc);
 int cdns_pcie_host_init(struct cdns_pcie_rc *rc);
 int cdns_pcie_host_setup(struct cdns_pcie_rc *rc);
@@ -548,7 +548,7 @@ static inline void __iomem *cdns_pci_map_bus(struct pci_bus *bus, unsigned int d
 }
 #endif
 
-#ifdef CONFIG_PCIE_CADENCE_EP
+#if IS_ENABLED(CONFIG_PCIE_CADENCE_EP)
 int cdns_pcie_ep_setup(struct cdns_pcie_ep *ep);
 #else
 static inline int cdns_pcie_ep_setup(struct cdns_pcie_ep *ep)
-- 
2.34.1

[PATCH v4 2/4] PCI: cadence-host: Introduce cdns_pcie_host_disable helper for cleanup

[Siddharth Vadapalli]

Introduce the helper function cdns_pcie_host_disable() which will undo
the configuration performed by cdns_pcie_host_setup(). Also, export it
for use by existing callers of cdns_pcie_host_setup(), thereby allowing
them to cleanup on their exit path.

Signed-off-by: Siddharth Vadapalli <s-vadapalli@ti.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---

v3 patch is at:
https://lore.kernel.org/r/20250410104426.463453-3-s-vadapalli@ti.com/
No changes since v3.

Regards,
Siddharth.

 .../controller/cadence/pcie-cadence-host.c    | 104 ++++++++++++++++++
 drivers/pci/controller/cadence/pcie-cadence.h |   5 +
 2 files changed, 109 insertions(+)

diff --git a/drivers/pci/controller/cadence/pcie-cadence-host.c b/drivers/pci/controller/cadence/pcie-cadence-host.c
index 96055edeb099..741508738f88 100644
--- a/drivers/pci/controller/cadence/pcie-cadence-host.c
+++ b/drivers/pci/controller/cadence/pcie-cadence-host.c
@@ -152,6 +152,14 @@ static int cdns_pcie_retrain(struct cdns_pcie *pcie)
 	return ret;
 }
 
+static void cdns_pcie_host_disable_ptm_response(struct cdns_pcie *pcie)
+{
+	u32 val;
+
+	val = cdns_pcie_readl(pcie, CDNS_PCIE_LM_PTM_CTRL);
+	cdns_pcie_writel(pcie, CDNS_PCIE_LM_PTM_CTRL, val & ~CDNS_PCIE_LM_TPM_CTRL_PTMRSEN);
+}
+
 static void cdns_pcie_host_enable_ptm_response(struct cdns_pcie *pcie)
 {
 	u32 val;
@@ -177,6 +185,26 @@ static int cdns_pcie_host_start_link(struct cdns_pcie_rc *rc)
 	return ret;
 }
 
+static void cdns_pcie_host_deinit_root_port(struct cdns_pcie_rc *rc)
+{
+	struct cdns_pcie *pcie = &rc->pcie;
+	u32 value, ctrl;
+
+	cdns_pcie_rp_writew(pcie, PCI_CLASS_DEVICE, 0xffff);
+	cdns_pcie_rp_writeb(pcie, PCI_CLASS_PROG, 0xff);
+	cdns_pcie_rp_writeb(pcie, PCI_CLASS_REVISION, 0xff);
+	cdns_pcie_writel(pcie, CDNS_PCIE_LM_ID, 0xffffffff);
+	cdns_pcie_rp_writew(pcie, PCI_DEVICE_ID, 0xffff);
+	ctrl = CDNS_PCIE_LM_BAR_CFG_CTRL_DISABLED;
+	value = ~(CDNS_PCIE_LM_RC_BAR_CFG_BAR0_CTRL(ctrl) |
+		CDNS_PCIE_LM_RC_BAR_CFG_BAR1_CTRL(ctrl) |
+		CDNS_PCIE_LM_RC_BAR_CFG_PREFETCH_MEM_ENABLE |
+		CDNS_PCIE_LM_RC_BAR_CFG_PREFETCH_MEM_64BITS |
+		CDNS_PCIE_LM_RC_BAR_CFG_IO_ENABLE |
+		CDNS_PCIE_LM_RC_BAR_CFG_IO_32BITS);
+	cdns_pcie_writel(pcie, CDNS_PCIE_LM_RC_BAR_CFG, value);
+}
+
 static int cdns_pcie_host_init_root_port(struct cdns_pcie_rc *rc)
 {
 	struct cdns_pcie *pcie = &rc->pcie;
@@ -393,6 +421,32 @@ static int cdns_pcie_host_dma_ranges_cmp(void *priv, const struct list_head *a,
         return resource_size(entry2->res) - resource_size(entry1->res);
 }
 
+static void cdns_pcie_host_unmap_dma_ranges(struct cdns_pcie_rc *rc)
+{
+	struct cdns_pcie *pcie = &rc->pcie;
+	enum cdns_pcie_rp_bar bar;
+	u32 value;
+
+	/* Reset inbound configuration for all BARs which were being used */
+	for (bar = RP_BAR0; bar <= RP_NO_BAR; bar++) {
+		if (rc->avail_ib_bar[bar])
+			continue;
+
+		cdns_pcie_writel(pcie, CDNS_PCIE_AT_IB_RP_BAR_ADDR0(bar), 0);
+		cdns_pcie_writel(pcie, CDNS_PCIE_AT_IB_RP_BAR_ADDR1(bar), 0);
+
+		if (bar == RP_NO_BAR)
+			continue;
+
+		value = ~(LM_RC_BAR_CFG_CTRL_MEM_64BITS(bar) |
+			  LM_RC_BAR_CFG_CTRL_PREF_MEM_64BITS(bar) |
+			  LM_RC_BAR_CFG_CTRL_MEM_32BITS(bar) |
+			  LM_RC_BAR_CFG_CTRL_PREF_MEM_32BITS(bar) |
+			  LM_RC_BAR_CFG_APERTURE(bar, bar_aperture_mask[bar] + 2));
+		cdns_pcie_writel(pcie, CDNS_PCIE_LM_RC_BAR_CFG, value);
+	}
+}
+
 static int cdns_pcie_host_map_dma_ranges(struct cdns_pcie_rc *rc)
 {
 	struct cdns_pcie *pcie = &rc->pcie;
@@ -430,6 +484,29 @@ static int cdns_pcie_host_map_dma_ranges(struct cdns_pcie_rc *rc)
 	return 0;
 }
 
+static void cdns_pcie_host_deinit_address_translation(struct cdns_pcie_rc *rc)
+{
+	struct cdns_pcie *pcie = &rc->pcie;
+	struct pci_host_bridge *bridge = pci_host_bridge_from_priv(rc);
+	struct resource_entry *entry;
+	int r;
+
+	cdns_pcie_host_unmap_dma_ranges(rc);
+
+	/*
+	 * Reset outbound region 0 which was reserved for configuration space
+	 * accesses.
+	 */
+	cdns_pcie_reset_outbound_region(pcie, 0);
+
+	/* Reset rest of the outbound regions */
+	r = 1;
+	resource_list_for_each_entry(entry, &bridge->windows) {
+		cdns_pcie_reset_outbound_region(pcie, r);
+		r++;
+	}
+}
+
 static int cdns_pcie_host_init_address_translation(struct cdns_pcie_rc *rc)
 {
 	struct cdns_pcie *pcie = &rc->pcie;
@@ -487,6 +564,12 @@ static int cdns_pcie_host_init_address_translation(struct cdns_pcie_rc *rc)
 	return cdns_pcie_host_map_dma_ranges(rc);
 }
 
+static void cdns_pcie_host_deinit(struct cdns_pcie_rc *rc)
+{
+	cdns_pcie_host_deinit_address_translation(rc);
+	cdns_pcie_host_deinit_root_port(rc);
+}
+
 int cdns_pcie_host_init(struct cdns_pcie_rc *rc)
 {
 	int err;
@@ -499,6 +582,14 @@ int cdns_pcie_host_init(struct cdns_pcie_rc *rc)
 }
 EXPORT_SYMBOL_GPL(cdns_pcie_host_init);
 
+static void cdns_pcie_host_link_disable(struct cdns_pcie_rc *rc)
+{
+	struct cdns_pcie *pcie = &rc->pcie;
+
+	cdns_pcie_stop_link(pcie);
+	cdns_pcie_host_disable_ptm_response(pcie);
+}
+
 int cdns_pcie_host_link_setup(struct cdns_pcie_rc *rc)
 {
 	struct cdns_pcie *pcie = &rc->pcie;
@@ -524,6 +615,19 @@ int cdns_pcie_host_link_setup(struct cdns_pcie_rc *rc)
 }
 EXPORT_SYMBOL_GPL(cdns_pcie_host_link_setup);
 
+void cdns_pcie_host_disable(struct cdns_pcie_rc *rc)
+{
+	struct pci_host_bridge *bridge;
+
+	bridge = pci_host_bridge_from_priv(rc);
+	pci_stop_root_bus(bridge->bus);
+	pci_remove_root_bus(bridge->bus);
+
+	cdns_pcie_host_deinit(rc);
+	cdns_pcie_host_link_disable(rc);
+}
+EXPORT_SYMBOL_GPL(cdns_pcie_host_disable);
+
 int cdns_pcie_host_setup(struct cdns_pcie_rc *rc)
 {
 	struct device *dev = rc->pcie.dev;
diff --git a/drivers/pci/controller/cadence/pcie-cadence.h b/drivers/pci/controller/cadence/pcie-cadence.h
index 4b7f295e24e7..0b6bed1ac146 100644
--- a/drivers/pci/controller/cadence/pcie-cadence.h
+++ b/drivers/pci/controller/cadence/pcie-cadence.h
@@ -523,6 +523,7 @@ static inline bool cdns_pcie_link_up(struct cdns_pcie *pcie)
 int cdns_pcie_host_link_setup(struct cdns_pcie_rc *rc);
 int cdns_pcie_host_init(struct cdns_pcie_rc *rc);
 int cdns_pcie_host_setup(struct cdns_pcie_rc *rc);
+void cdns_pcie_host_disable(struct cdns_pcie_rc *rc);
 void __iomem *cdns_pci_map_bus(struct pci_bus *bus, unsigned int devfn,
 			       int where);
 #else
@@ -541,6 +542,10 @@ static inline int cdns_pcie_host_setup(struct cdns_pcie_rc *rc)
 	return 0;
 }
 
+static inline void cdns_pcie_host_disable(struct cdns_pcie_rc *rc)
+{
+}
+
 static inline void __iomem *cdns_pci_map_bus(struct pci_bus *bus, unsigned int devfn,
 					     int where)
 {
-- 
2.34.1

Re: [PATCH v4 2/4] PCI: cadence-host: Introduce cdns_pcie_host_disable helper for cleanup

[Bjorn Helgaas]

On Thu, Apr 17, 2025 at 06:14:06PM +0530, Siddharth Vadapalli wrote:
> Introduce the helper function cdns_pcie_host_disable() which will undo
> the configuration performed by cdns_pcie_host_setup(). Also, export it
> for use by existing callers of cdns_pcie_host_setup(), thereby allowing
> them to cleanup on their exit path.

For the merge commit log and eventual pull request, can you give me a
hint about the motivation for this?  Based on the other patches in
this series, my guess is that this is required for making the j721e
driver buildable as a module and removable?

> Signed-off-by: Siddharth Vadapalli <s-vadapalli@ti.com>
> Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> ---
> 
> v3 patch is at:
> https://lore.kernel.org/r/20250410104426.463453-3-s-vadapalli@ti.com/
> No changes since v3.
> 
> Regards,
> Siddharth.
> 
>  .../controller/cadence/pcie-cadence-host.c    | 104 ++++++++++++++++++
>  drivers/pci/controller/cadence/pcie-cadence.h |   5 +
>  2 files changed, 109 insertions(+)
> 
> diff --git a/drivers/pci/controller/cadence/pcie-cadence-host.c b/drivers/pci/controller/cadence/pcie-cadence-host.c
> index 96055edeb099..741508738f88 100644
> --- a/drivers/pci/controller/cadence/pcie-cadence-host.c
> +++ b/drivers/pci/controller/cadence/pcie-cadence-host.c
> @@ -152,6 +152,14 @@ static int cdns_pcie_retrain(struct cdns_pcie *pcie)
>  	return ret;
>  }
>  
> +static void cdns_pcie_host_disable_ptm_response(struct cdns_pcie *pcie)
> +{
> +	u32 val;
> +
> +	val = cdns_pcie_readl(pcie, CDNS_PCIE_LM_PTM_CTRL);
> +	cdns_pcie_writel(pcie, CDNS_PCIE_LM_PTM_CTRL, val & ~CDNS_PCIE_LM_TPM_CTRL_PTMRSEN);
> +}
> +
>  static void cdns_pcie_host_enable_ptm_response(struct cdns_pcie *pcie)
>  {
>  	u32 val;
> @@ -177,6 +185,26 @@ static int cdns_pcie_host_start_link(struct cdns_pcie_rc *rc)
>  	return ret;
>  }
>  
> +static void cdns_pcie_host_deinit_root_port(struct cdns_pcie_rc *rc)
> +{
> +	struct cdns_pcie *pcie = &rc->pcie;
> +	u32 value, ctrl;
> +
> +	cdns_pcie_rp_writew(pcie, PCI_CLASS_DEVICE, 0xffff);
> +	cdns_pcie_rp_writeb(pcie, PCI_CLASS_PROG, 0xff);
> +	cdns_pcie_rp_writeb(pcie, PCI_CLASS_REVISION, 0xff);
> +	cdns_pcie_writel(pcie, CDNS_PCIE_LM_ID, 0xffffffff);
> +	cdns_pcie_rp_writew(pcie, PCI_DEVICE_ID, 0xffff);
> +	ctrl = CDNS_PCIE_LM_BAR_CFG_CTRL_DISABLED;
> +	value = ~(CDNS_PCIE_LM_RC_BAR_CFG_BAR0_CTRL(ctrl) |
> +		CDNS_PCIE_LM_RC_BAR_CFG_BAR1_CTRL(ctrl) |
> +		CDNS_PCIE_LM_RC_BAR_CFG_PREFETCH_MEM_ENABLE |
> +		CDNS_PCIE_LM_RC_BAR_CFG_PREFETCH_MEM_64BITS |
> +		CDNS_PCIE_LM_RC_BAR_CFG_IO_ENABLE |
> +		CDNS_PCIE_LM_RC_BAR_CFG_IO_32BITS);
> +	cdns_pcie_writel(pcie, CDNS_PCIE_LM_RC_BAR_CFG, value);
> +}
> +
>  static int cdns_pcie_host_init_root_port(struct cdns_pcie_rc *rc)
>  {
>  	struct cdns_pcie *pcie = &rc->pcie;
> @@ -393,6 +421,32 @@ static int cdns_pcie_host_dma_ranges_cmp(void *priv, const struct list_head *a,
>          return resource_size(entry2->res) - resource_size(entry1->res);
>  }
>  
> +static void cdns_pcie_host_unmap_dma_ranges(struct cdns_pcie_rc *rc)
> +{
> +	struct cdns_pcie *pcie = &rc->pcie;
> +	enum cdns_pcie_rp_bar bar;
> +	u32 value;
> +
> +	/* Reset inbound configuration for all BARs which were being used */
> +	for (bar = RP_BAR0; bar <= RP_NO_BAR; bar++) {
> +		if (rc->avail_ib_bar[bar])
> +			continue;
> +
> +		cdns_pcie_writel(pcie, CDNS_PCIE_AT_IB_RP_BAR_ADDR0(bar), 0);
> +		cdns_pcie_writel(pcie, CDNS_PCIE_AT_IB_RP_BAR_ADDR1(bar), 0);
> +
> +		if (bar == RP_NO_BAR)
> +			continue;
> +
> +		value = ~(LM_RC_BAR_CFG_CTRL_MEM_64BITS(bar) |
> +			  LM_RC_BAR_CFG_CTRL_PREF_MEM_64BITS(bar) |
> +			  LM_RC_BAR_CFG_CTRL_MEM_32BITS(bar) |
> +			  LM_RC_BAR_CFG_CTRL_PREF_MEM_32BITS(bar) |
> +			  LM_RC_BAR_CFG_APERTURE(bar, bar_aperture_mask[bar] + 2));
> +		cdns_pcie_writel(pcie, CDNS_PCIE_LM_RC_BAR_CFG, value);
> +	}
> +}
> +
>  static int cdns_pcie_host_map_dma_ranges(struct cdns_pcie_rc *rc)
>  {
>  	struct cdns_pcie *pcie = &rc->pcie;
> @@ -430,6 +484,29 @@ static int cdns_pcie_host_map_dma_ranges(struct cdns_pcie_rc *rc)
>  	return 0;
>  }
>  
> +static void cdns_pcie_host_deinit_address_translation(struct cdns_pcie_rc *rc)
> +{
> +	struct cdns_pcie *pcie = &rc->pcie;
> +	struct pci_host_bridge *bridge = pci_host_bridge_from_priv(rc);
> +	struct resource_entry *entry;
> +	int r;
> +
> +	cdns_pcie_host_unmap_dma_ranges(rc);
> +
> +	/*
> +	 * Reset outbound region 0 which was reserved for configuration space
> +	 * accesses.
> +	 */
> +	cdns_pcie_reset_outbound_region(pcie, 0);
> +
> +	/* Reset rest of the outbound regions */
> +	r = 1;
> +	resource_list_for_each_entry(entry, &bridge->windows) {
> +		cdns_pcie_reset_outbound_region(pcie, r);
> +		r++;
> +	}
> +}
> +
>  static int cdns_pcie_host_init_address_translation(struct cdns_pcie_rc *rc)
>  {
>  	struct cdns_pcie *pcie = &rc->pcie;
> @@ -487,6 +564,12 @@ static int cdns_pcie_host_init_address_translation(struct cdns_pcie_rc *rc)
>  	return cdns_pcie_host_map_dma_ranges(rc);
>  }
>  
> +static void cdns_pcie_host_deinit(struct cdns_pcie_rc *rc)
> +{
> +	cdns_pcie_host_deinit_address_translation(rc);
> +	cdns_pcie_host_deinit_root_port(rc);
> +}
> +
>  int cdns_pcie_host_init(struct cdns_pcie_rc *rc)
>  {
>  	int err;
> @@ -499,6 +582,14 @@ int cdns_pcie_host_init(struct cdns_pcie_rc *rc)
>  }
>  EXPORT_SYMBOL_GPL(cdns_pcie_host_init);
>  
> +static void cdns_pcie_host_link_disable(struct cdns_pcie_rc *rc)
> +{
> +	struct cdns_pcie *pcie = &rc->pcie;
> +
> +	cdns_pcie_stop_link(pcie);
> +	cdns_pcie_host_disable_ptm_response(pcie);
> +}
> +
>  int cdns_pcie_host_link_setup(struct cdns_pcie_rc *rc)
>  {
>  	struct cdns_pcie *pcie = &rc->pcie;
> @@ -524,6 +615,19 @@ int cdns_pcie_host_link_setup(struct cdns_pcie_rc *rc)
>  }
>  EXPORT_SYMBOL_GPL(cdns_pcie_host_link_setup);
>  
> +void cdns_pcie_host_disable(struct cdns_pcie_rc *rc)
> +{
> +	struct pci_host_bridge *bridge;
> +
> +	bridge = pci_host_bridge_from_priv(rc);
> +	pci_stop_root_bus(bridge->bus);
> +	pci_remove_root_bus(bridge->bus);
> +
> +	cdns_pcie_host_deinit(rc);
> +	cdns_pcie_host_link_disable(rc);
> +}
> +EXPORT_SYMBOL_GPL(cdns_pcie_host_disable);
> +
>  int cdns_pcie_host_setup(struct cdns_pcie_rc *rc)
>  {
>  	struct device *dev = rc->pcie.dev;
> diff --git a/drivers/pci/controller/cadence/pcie-cadence.h b/drivers/pci/controller/cadence/pcie-cadence.h
> index 4b7f295e24e7..0b6bed1ac146 100644
> --- a/drivers/pci/controller/cadence/pcie-cadence.h
> +++ b/drivers/pci/controller/cadence/pcie-cadence.h
> @@ -523,6 +523,7 @@ static inline bool cdns_pcie_link_up(struct cdns_pcie *pcie)
>  int cdns_pcie_host_link_setup(struct cdns_pcie_rc *rc);
>  int cdns_pcie_host_init(struct cdns_pcie_rc *rc);
>  int cdns_pcie_host_setup(struct cdns_pcie_rc *rc);
> +void cdns_pcie_host_disable(struct cdns_pcie_rc *rc);
>  void __iomem *cdns_pci_map_bus(struct pci_bus *bus, unsigned int devfn,
>  			       int where);
>  #else
> @@ -541,6 +542,10 @@ static inline int cdns_pcie_host_setup(struct cdns_pcie_rc *rc)
>  	return 0;
>  }
>  
> +static inline void cdns_pcie_host_disable(struct cdns_pcie_rc *rc)
> +{
> +}
> +
>  static inline void __iomem *cdns_pci_map_bus(struct pci_bus *bus, unsigned int devfn,
>  					     int where)
>  {
> -- 
> 2.34.1
> 

Re: [PATCH v4 2/4] PCI: cadence-host: Introduce cdns_pcie_host_disable helper for cleanup

[Siddharth Vadapalli]

On Tue, Apr 22, 2025 at 11:49:34AM -0500, Bjorn Helgaas wrote:

Hello Bjorn,

> On Thu, Apr 17, 2025 at 06:14:06PM +0530, Siddharth Vadapalli wrote:
> > Introduce the helper function cdns_pcie_host_disable() which will undo
> > the configuration performed by cdns_pcie_host_setup(). Also, export it
> > for use by existing callers of cdns_pcie_host_setup(), thereby allowing
> > them to cleanup on their exit path.
> 
> For the merge commit log and eventual pull request, can you give me a
> hint about the motivation for this?  Based on the other patches in
> this series, my guess is that this is required for making the j721e
> driver buildable as a module and removable?

I have described the motivation in the cover-letter of this series in
detail. I am sharing the same below for your reference:

"The motivation for this series is that PCIe is not a necessity
for booting the SoC, due to which it doesn't have to be a built-in
module. Additionally, the defconfig doesn't enable the PCIe Cadence
Controller drivers and the PCI J721E driver, due to which PCIe is not
supported by default. Enabling the configs as of now (i.e. without this
series) will result in built-in drivers i.e. a bloated Linux Image for
everyone who doesn't have the PCIe Controller. Therefore, with this
series, after enabling support for building the drivers as loadable
modules, the driver configs can be enabled in the defconfig to build
the drivers as loadable modules, thereby enabling PCIe."

In brief, in order to enable the driver configs, the driver needs to be
a loadable module. Else, the patch for the configs will be rejected:
https://lore.kernel.org/linux-arm-kernel/20250122145822.4ewsmkk6ztbeejzf@slashing/

Regards,
Siddharth.

[PATCH v4 3/4] PCI: cadence-ep: Introduce cdns_pcie_ep_disable helper for cleanup

[Siddharth Vadapalli]

Introduce the helper function cdns_pcie_ep_disable() which will undo the
configuration performed by cdns_pcie_ep_setup(). Also, export it for use
by the existing callers of cdns_pcie_ep_setup(), thereby allowing them
to cleanup on their exit path.

Signed-off-by: Siddharth Vadapalli <s-vadapalli@ti.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---

v3 patch is at:
https://lore.kernel.org/r/20250410104426.463453-4-s-vadapalli@ti.com/
No changes since v3.

Regards,
Siddharth.

 drivers/pci/controller/cadence/pcie-cadence-ep.c | 11 +++++++++++
 drivers/pci/controller/cadence/pcie-cadence.h    |  5 +++++
 2 files changed, 16 insertions(+)

diff --git a/drivers/pci/controller/cadence/pcie-cadence-ep.c b/drivers/pci/controller/cadence/pcie-cadence-ep.c
index b4bcef2d020a..ffd19cb25eed 100644
--- a/drivers/pci/controller/cadence/pcie-cadence-ep.c
+++ b/drivers/pci/controller/cadence/pcie-cadence-ep.c
@@ -645,6 +645,17 @@ static const struct pci_epc_ops cdns_pcie_epc_ops = {
 	.get_features	= cdns_pcie_ep_get_features,
 };
 
+void cdns_pcie_ep_disable(struct cdns_pcie_ep *ep)
+{
+	struct device *dev = ep->pcie.dev;
+	struct pci_epc *epc = to_pci_epc(dev);
+
+	pci_epc_deinit_notify(epc);
+	pci_epc_mem_free_addr(epc, ep->irq_phys_addr, ep->irq_cpu_addr,
+			      SZ_128K);
+	pci_epc_mem_exit(epc);
+}
+EXPORT_SYMBOL_GPL(cdns_pcie_ep_disable);
 
 int cdns_pcie_ep_setup(struct cdns_pcie_ep *ep)
 {
diff --git a/drivers/pci/controller/cadence/pcie-cadence.h b/drivers/pci/controller/cadence/pcie-cadence.h
index 0b6bed1ac146..387174d6e453 100644
--- a/drivers/pci/controller/cadence/pcie-cadence.h
+++ b/drivers/pci/controller/cadence/pcie-cadence.h
@@ -555,11 +555,16 @@ static inline void __iomem *cdns_pci_map_bus(struct pci_bus *bus, unsigned int d
 
 #if IS_ENABLED(CONFIG_PCIE_CADENCE_EP)
 int cdns_pcie_ep_setup(struct cdns_pcie_ep *ep);
+void cdns_pcie_ep_disable(struct cdns_pcie_ep *ep);
 #else
 static inline int cdns_pcie_ep_setup(struct cdns_pcie_ep *ep)
 {
 	return 0;
 }
+
+static inline void cdns_pcie_ep_disable(struct cdns_pcie_ep *ep)
+{
+}
 #endif
 
 void cdns_pcie_detect_quiet_min_delay_set(struct cdns_pcie *pcie);
-- 
2.34.1

[PATCH v4 4/4] PCI: j721e: Add support to build as a loadable module

[Siddharth Vadapalli]

The 'pci-j721e.c' driver is the application/glue/wrapper driver for the
Cadence PCIe Controllers on TI SoCs. Implement support for building it as a
loadable module.

Signed-off-by: Siddharth Vadapalli <s-vadapalli@ti.com>
---

v3 patch is at:
https://lore.kernel.org/r/20250410104426.463453-5-s-vadapalli@ti.com/
Changes since v3:
- In the fourth patch of this series, the polarity for PERST# assert in
  the driver's .remove callback has been fixed based on Mani's feedback at
  https://lore.kernel.org/r/6bi5gul3sqvycmkf6cwokkvownjffaf2tkonjlefo2d7cautwx@uhfexzgz3okp/

Regards,
Siddharth.

 drivers/pci/controller/cadence/Kconfig     |  6 ++---
 drivers/pci/controller/cadence/pci-j721e.c | 31 +++++++++++++++++++++-
 2 files changed, 33 insertions(+), 4 deletions(-)

diff --git a/drivers/pci/controller/cadence/Kconfig b/drivers/pci/controller/cadence/Kconfig
index 82b58096eea0..72d7d264d6c3 100644
--- a/drivers/pci/controller/cadence/Kconfig
+++ b/drivers/pci/controller/cadence/Kconfig
@@ -43,10 +43,10 @@ config PCIE_CADENCE_PLAT_EP
 	  different vendors SoCs.
 
 config PCI_J721E
-	bool
+	tristate
 
 config PCI_J721E_HOST
-	bool "TI J721E PCIe controller (host mode)"
+	tristate "TI J721E PCIe controller (host mode)"
 	depends on ARCH_K3 || COMPILE_TEST
 	depends on OF
 	select PCIE_CADENCE_HOST
@@ -57,7 +57,7 @@ config PCI_J721E_HOST
 	  core.
 
 config PCI_J721E_EP
-	bool "TI J721E PCIe controller (endpoint mode)"
+	tristate "TI J721E PCIe controller (endpoint mode)"
 	depends on ARCH_K3 || COMPILE_TEST
 	depends on OF
 	depends on PCI_ENDPOINT
diff --git a/drivers/pci/controller/cadence/pci-j721e.c b/drivers/pci/controller/cadence/pci-j721e.c
index ef1cfdae33bb..8a73a4d382d1 100644
--- a/drivers/pci/controller/cadence/pci-j721e.c
+++ b/drivers/pci/controller/cadence/pci-j721e.c
@@ -15,6 +15,7 @@
 #include <linux/irqchip/chained_irq.h>
 #include <linux/irqdomain.h>
 #include <linux/mfd/syscon.h>
+#include <linux/module.h>
 #include <linux/of.h>
 #include <linux/pci.h>
 #include <linux/platform_device.h>
@@ -27,6 +28,7 @@
 #define cdns_pcie_to_rc(p) container_of(p, struct cdns_pcie_rc, pcie)
 
 #define ENABLE_REG_SYS_2	0x108
+#define ENABLE_CLR_REG_SYS_2	0x308
 #define STATUS_REG_SYS_2	0x508
 #define STATUS_CLR_REG_SYS_2	0x708
 #define LINK_DOWN		BIT(1)
@@ -116,6 +118,15 @@ static irqreturn_t j721e_pcie_link_irq_handler(int irq, void *priv)
 	return IRQ_HANDLED;
 }
 
+static void j721e_pcie_disable_link_irq(struct j721e_pcie *pcie)
+{
+	u32 reg;
+
+	reg = j721e_pcie_intd_readl(pcie, ENABLE_CLR_REG_SYS_2);
+	reg |= pcie->linkdown_irq_regfield;
+	j721e_pcie_intd_writel(pcie, ENABLE_CLR_REG_SYS_2, reg);
+}
+
 static void j721e_pcie_config_link_irq(struct j721e_pcie *pcie)
 {
 	u32 reg;
@@ -633,9 +644,23 @@ static void j721e_pcie_remove(struct platform_device *pdev)
 	struct j721e_pcie *pcie = platform_get_drvdata(pdev);
 	struct cdns_pcie *cdns_pcie = pcie->cdns_pcie;
 	struct device *dev = &pdev->dev;
+	struct cdns_pcie_ep *ep;
+	struct cdns_pcie_rc *rc;
+
+	if (pcie->mode == PCI_MODE_RC) {
+		rc = container_of(cdns_pcie, struct cdns_pcie_rc, pcie);
+		cdns_pcie_host_disable(rc);
+	} else {
+		ep = container_of(cdns_pcie, struct cdns_pcie_ep, pcie);
+		cdns_pcie_ep_disable(ep);
+	}
+
+	if (pcie->reset_gpio)
+		gpiod_set_value_cansleep(pcie->reset_gpio, 0);
 
 	clk_disable_unprepare(pcie->refclk);
 	cdns_pcie_disable_phy(cdns_pcie);
+	j721e_pcie_disable_link_irq(pcie);
 	pm_runtime_put(dev);
 	pm_runtime_disable(dev);
 }
@@ -730,4 +755,8 @@ static struct platform_driver j721e_pcie_driver = {
 		.pm	= pm_sleep_ptr(&j721e_pcie_pm_ops),
 	},
 };
-builtin_platform_driver(j721e_pcie_driver);
+module_platform_driver(j721e_pcie_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("PCIe controller driver for TI's J721E and related SoCs");
+MODULE_AUTHOR("Kishon Vijay Abraham I <kishon@ti.com>");
-- 
2.34.1

Re: [PATCH v4 4/4] PCI: j721e: Add support to build as a loadable module

[Manivannan Sadhasivam]

On Thu, Apr 17, 2025 at 06:14:08PM +0530, Siddharth Vadapalli wrote:
> The 'pci-j721e.c' driver is the application/glue/wrapper driver for the
> Cadence PCIe Controllers on TI SoCs. Implement support for building it as a
> loadable module.
> 
> Signed-off-by: Siddharth Vadapalli <s-vadapalli@ti.com>

One nitpick below. But no need to respin just for this. Hopefully, this can be
changed while applying the series.

Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

> ---
> 
> v3 patch is at:
> https://lore.kernel.org/r/20250410104426.463453-5-s-vadapalli@ti.com/
> Changes since v3:
> - In the fourth patch of this series, the polarity for PERST# assert in
>   the driver's .remove callback has been fixed based on Mani's feedback at
>   https://lore.kernel.org/r/6bi5gul3sqvycmkf6cwokkvownjffaf2tkonjlefo2d7cautwx@uhfexzgz3okp/
> 
> Regards,
> Siddharth.
> 
>  drivers/pci/controller/cadence/Kconfig     |  6 ++---
>  drivers/pci/controller/cadence/pci-j721e.c | 31 +++++++++++++++++++++-
>  2 files changed, 33 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/pci/controller/cadence/Kconfig b/drivers/pci/controller/cadence/Kconfig
> index 82b58096eea0..72d7d264d6c3 100644
> --- a/drivers/pci/controller/cadence/Kconfig
> +++ b/drivers/pci/controller/cadence/Kconfig
> @@ -43,10 +43,10 @@ config PCIE_CADENCE_PLAT_EP
>  	  different vendors SoCs.
>  
>  config PCI_J721E
> -	bool
> +	tristate
>  
>  config PCI_J721E_HOST
> -	bool "TI J721E PCIe controller (host mode)"
> +	tristate "TI J721E PCIe controller (host mode)"
>  	depends on ARCH_K3 || COMPILE_TEST
>  	depends on OF
>  	select PCIE_CADENCE_HOST
> @@ -57,7 +57,7 @@ config PCI_J721E_HOST
>  	  core.
>  
>  config PCI_J721E_EP
> -	bool "TI J721E PCIe controller (endpoint mode)"
> +	tristate "TI J721E PCIe controller (endpoint mode)"
>  	depends on ARCH_K3 || COMPILE_TEST
>  	depends on OF
>  	depends on PCI_ENDPOINT
> diff --git a/drivers/pci/controller/cadence/pci-j721e.c b/drivers/pci/controller/cadence/pci-j721e.c
> index ef1cfdae33bb..8a73a4d382d1 100644
> --- a/drivers/pci/controller/cadence/pci-j721e.c
> +++ b/drivers/pci/controller/cadence/pci-j721e.c
> @@ -15,6 +15,7 @@
>  #include <linux/irqchip/chained_irq.h>
>  #include <linux/irqdomain.h>
>  #include <linux/mfd/syscon.h>
> +#include <linux/module.h>
>  #include <linux/of.h>
>  #include <linux/pci.h>
>  #include <linux/platform_device.h>
> @@ -27,6 +28,7 @@
>  #define cdns_pcie_to_rc(p) container_of(p, struct cdns_pcie_rc, pcie)
>  
>  #define ENABLE_REG_SYS_2	0x108
> +#define ENABLE_CLR_REG_SYS_2	0x308
>  #define STATUS_REG_SYS_2	0x508
>  #define STATUS_CLR_REG_SYS_2	0x708
>  #define LINK_DOWN		BIT(1)
> @@ -116,6 +118,15 @@ static irqreturn_t j721e_pcie_link_irq_handler(int irq, void *priv)
>  	return IRQ_HANDLED;
>  }
>  
> +static void j721e_pcie_disable_link_irq(struct j721e_pcie *pcie)
> +{
> +	u32 reg;
> +
> +	reg = j721e_pcie_intd_readl(pcie, ENABLE_CLR_REG_SYS_2);
> +	reg |= pcie->linkdown_irq_regfield;
> +	j721e_pcie_intd_writel(pcie, ENABLE_CLR_REG_SYS_2, reg);
> +}
> +
>  static void j721e_pcie_config_link_irq(struct j721e_pcie *pcie)
>  {
>  	u32 reg;
> @@ -633,9 +644,23 @@ static void j721e_pcie_remove(struct platform_device *pdev)
>  	struct j721e_pcie *pcie = platform_get_drvdata(pdev);
>  	struct cdns_pcie *cdns_pcie = pcie->cdns_pcie;
>  	struct device *dev = &pdev->dev;
> +	struct cdns_pcie_ep *ep;
> +	struct cdns_pcie_rc *rc;
> +
> +	if (pcie->mode == PCI_MODE_RC) {
> +		rc = container_of(cdns_pcie, struct cdns_pcie_rc, pcie);
> +		cdns_pcie_host_disable(rc);
> +	} else {
> +		ep = container_of(cdns_pcie, struct cdns_pcie_ep, pcie);
> +		cdns_pcie_ep_disable(ep);
> +	}
> +
> +	if (pcie->reset_gpio)

All 'gpiod_*' APIs accept NULL descriptors. So you don't necessarily need the
check here.

- Mani

-- 
மணிவண்ணன் சதாசிவம்

Re: [PATCH v4 0/4] Loadable Module support for PCIe Cadence and J721E

[Manivannan Sadhasivam]

On Thu, 17 Apr 2025 18:14:04 +0530, Siddharth Vadapalli wrote:
> This series enables support to build the PCIe Cadence Controller drivers
> and the PCI J721E Application/Wrapper/Glue driver as Loadable Kernel
> Modules. The motivation for this series is that PCIe is not a necessity
> for booting the SoC, due to which it doesn't have to be a built-in
> module. Additionally, the defconfig doesn't enable the PCIe Cadence
> Controller drivers and the PCI J721E driver, due to which PCIe is not
> supported by default. Enabling the configs as of now (i.e. without this
> series) will result in built-in drivers i.e. a bloated Linux Image for
> everyone who doesn't have the PCIe Controller. Therefore, with this
> series, after enabling support for building the drivers as loadable
> modules, the driver configs can be enabled in the defconfig to build
> the drivers as loadable modules, thereby enabling PCIe.
> 
> [...]

Applied, thanks!

[1/4] PCI: cadence: Add support to build pcie-cadence library as a kernel module
      commit: b51c6fee0a06b71e9bf610f4b294426d0a1f1b51
[2/4] PCI: cadence-host: Introduce cdns_pcie_host_disable helper for cleanup
      commit: 23c498ea9abd7bed7d0f8c1c5f63459100b01028
[3/4] PCI: cadence-ep: Introduce cdns_pcie_ep_disable helper for cleanup
      commit: 5f8c840aa407588a7eae89af1301ba19c307aab7
[4/4] PCI: j721e: Add support to build as a loadable module
      commit: 7a68d4ab59fa66ebbd9b8abdbffcaf748e109ad7

Best regards,
-- 
Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>