[PATCH V3 0/7] Add loadable kernel module and power management support

[PATCH V3 0/7] Add loadable kernel module and power management support

[Manikanta Maddireddy]

This series of patches add loadable kernel module and power management
support to Tegra PCIe host controller driver.

These patches are tested on Jetson TK1, TX1 and TX2 platforms, following
are the verification details.
	- Multiple module insert & remove
	- PCIe device functionality after module insert
	- Free clock, resets, regulators, powergate, iomem and interrupt
	resources after module remove
	- PCIe device functionality after resume from RAM

Tegra PCIe host controller driver is using ioremap_page_range() which is
not exported. This is switched with devm_ioremap() in the series
'https://patchwork.ozlabs.org/project/linux-tegra/list/?series=9907'.

V2: PM QoS fix is dropped in V2 from this series because the fix is
incorporated in latest 'commit 0759e80b84e3 ("PM / QoS: Fix device resume
latency framework")'. Update commit message of few patches in V2.

V3: Patches to export irq_set_msi_desc() and tegra_cpuidle_pcie_irqs_in_use()
are dropped based on review comments. These symbols will be addressed in
next series. Remove PCI_REASSIGN_ALL_BUS flag for Tegra PCIe and took care
of few other review comments.

Manikanta Maddireddy (7):
  of: Export of_pci_range_to_resource()
  PCI: Export pci_find_host_bridge()
  PCI: tegra: Remove PCI_REASSIGN_ALL_BUS flag for Tegra PCIe
  PCI: tegra: Free resources on probe failure
  PCI: tegra: Add loadable kernel module support
  PCI: tegra: Broadcast PME_Turn_Off message before link goes to L2
  PCI: tegra: Add power management support

 drivers/of/address.c         |   1 +
 drivers/pci/host-bridge.c    |   1 +
 drivers/pci/host/Kconfig     |   2 +-
 drivers/pci/host/pci-tegra.c | 331 +++++++++++++++++++++++++++++++++----------
 4 files changed, 257 insertions(+), 78 deletions(-)

-- 
2.1.4

[PATCH V3 1/7] of: Export of_pci_range_to_resource()

[Manikanta Maddireddy]

Tegra PCIe host driver parses of_pci_range from device tree and converts
to resource. Export of_pci_range_to_resource() to allow Tegra PCIe host
driver to be compiled as loadable kernel module.

Signed-off-by: Manikanta Maddireddy <mmaddireddy@nvidia.com>
Acked-by: Rob Herring <robh@kernel.org>
---
V2:
* commit message update
V3:
* no change in this patch

 drivers/of/address.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/of/address.c b/drivers/of/address.c
index fa6cabfc3cb9..8d9b93f8701a 100644
--- a/drivers/of/address.c
+++ b/drivers/of/address.c
@@ -361,6 +361,7 @@ int of_pci_range_to_resource(struct of_pci_range *range,
 	res->end = (resource_size_t)OF_BAD_ADDR;
 	return err;
 }
+EXPORT_SYMBOL(of_pci_range_to_resource);
 #endif /* CONFIG_PCI */
 
 /*
-- 
2.1.4

[PATCH V3 3/7] PCI: tegra: Remove PCI_REASSIGN_ALL_BUS flag for Tegra PCIe

[Manikanta Maddireddy]

Primary, secondary and subordinate default bus numbers are 0 in Tegra and
it is expecting SW to program these numbers in configration space.

pci_scan_bridge_extend() function programs these numbers in configuration
space if secondary & subordinate bus numbers are 0 or PCI_REASSIGN_ALL_BUS
flag is set. Since secondary & subordinate default bus numbers are 0,
PCI_REASSIGN_ALL_BUS flag can be removed for Tegra PCIe.

Signed-off-by: Manikanta Maddireddy <mmaddireddy@nvidia.com>
---
V3:
* new patch in V3

 drivers/pci/host/pci-tegra.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/pci/host/pci-tegra.c b/drivers/pci/host/pci-tegra.c
index 72a316940723..2a108c798846 100644
--- a/drivers/pci/host/pci-tegra.c
+++ b/drivers/pci/host/pci-tegra.c
@@ -2706,7 +2706,6 @@ static int tegra_pcie_probe(struct platform_device *pdev)
 
 	tegra_pcie_enable_ports(pcie);
 
-	pci_add_flags(PCI_REASSIGN_ALL_BUS);
 	host->busnr = pcie->busn.start;
 	host->dev.parent = &pdev->dev;
 	host->ops = &tegra_pcie_ops;
-- 
2.1.4

[PATCH V3 2/7] PCI: Export pci_find_host_bridge()

[Manikanta Maddireddy]

PCI subsystem pass pci_bus pointer to pci_ops callback functions, Tegra
host driver use pci_find_host_bridge() to get pci_host_bridge from pci_bus.
Export pci_find_host_bridge() to allow Tegra PCIe driver to be compiled as
loadable kernel module.

Signed-off-by: Manikanta Maddireddy <mmaddireddy-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
---
V2:
* commit message update
V3:
* EXPORT_SYMBOL is changed to EXPORT_SYMBOL_GPL

 drivers/pci/host-bridge.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/pci/host-bridge.c b/drivers/pci/host-bridge.c
index add66236215c..b8c0fcde9bd7 100644
--- a/drivers/pci/host-bridge.c
+++ b/drivers/pci/host-bridge.c
@@ -22,6 +22,7 @@ struct pci_host_bridge *pci_find_host_bridge(struct pci_bus *bus)
 
 	return to_pci_host_bridge(root_bus->bridge);
 }
+EXPORT_SYMBOL_GPL(pci_find_host_bridge);
 
 struct device *pci_get_host_bridge_device(struct pci_dev *dev)
 {
-- 
2.1.4

Re: [PATCH V3 2/7] PCI: Export pci_find_host_bridge()

[Bjorn Helgaas]

On Fri, Dec 01, 2017 at 02:50:02PM +0530, Manikanta Maddireddy wrote:
> PCI subsystem pass pci_bus pointer to pci_ops callback functions, Tegra

s/PCI subsystem pass/The PCI subsystem passes a/
s/, Tegra/.  The Tegra/

> host driver use pci_find_host_bridge() to get pci_host_bridge from pci_bus.

s/use/uses/

> Export pci_find_host_bridge() to allow Tegra PCIe driver to be compiled as
> loadable kernel module.

s/allow Tegra/allow the Tegra/
s/loadable/a loadable/

But why do you need pci_find_host_bridge() at all?  Most drivers use
the pci_bus.sysdata pointer for this purpose, e.g., see db271747a04d
("PCI: mediatek: Use bus->sysdata to get host private data")

> Signed-off-by: Manikanta Maddireddy <mmaddireddy-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
> ---
> V2:
> * commit message update
> V3:
> * EXPORT_SYMBOL is changed to EXPORT_SYMBOL_GPL
> 
>  drivers/pci/host-bridge.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/pci/host-bridge.c b/drivers/pci/host-bridge.c
> index add66236215c..b8c0fcde9bd7 100644
> --- a/drivers/pci/host-bridge.c
> +++ b/drivers/pci/host-bridge.c
> @@ -22,6 +22,7 @@ struct pci_host_bridge *pci_find_host_bridge(struct pci_bus *bus)
>  
>  	return to_pci_host_bridge(root_bus->bridge);
>  }
> +EXPORT_SYMBOL_GPL(pci_find_host_bridge);
>  
>  struct device *pci_get_host_bridge_device(struct pci_dev *dev)
>  {
> -- 
> 2.1.4
> 

Re: [PATCH V3 2/7] PCI: Export pci_find_host_bridge()

[Manikanta Maddireddy]

On 06-Dec-17 1:34 AM, Bjorn Helgaas wrote:
> On Fri, Dec 01, 2017 at 02:50:02PM +0530, Manikanta Maddireddy wrote:
>> PCI subsystem pass pci_bus pointer to pci_ops callback functions, Tegra
> 
> s/PCI subsystem pass/The PCI subsystem passes a/
> s/, Tegra/.  The Tegra/
> 
>> host driver use pci_find_host_bridge() to get pci_host_bridge from pci_bus.
> 
> s/use/uses/
> 
>> Export pci_find_host_bridge() to allow Tegra PCIe driver to be compiled as
>> loadable kernel module.
> 
> s/allow Tegra/allow the Tegra/
> s/loadable/a loadable/
> 
> But why do you need pci_find_host_bridge() at all?  Most drivers use
> the pci_bus.sysdata pointer for this purpose, e.g., see db271747a04d
> ("PCI: mediatek: Use bus->sysdata to get host private data")
> 

I will send a patch to use bus->sysdata instead of pci_find_host_bridge().

>> Signed-off-by: Manikanta Maddireddy <mmaddireddy-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
>> ---
>> V2:
>> * commit message update
>> V3:
>> * EXPORT_SYMBOL is changed to EXPORT_SYMBOL_GPL
>>
>>  drivers/pci/host-bridge.c | 1 +
>>  1 file changed, 1 insertion(+)
>>
>> diff --git a/drivers/pci/host-bridge.c b/drivers/pci/host-bridge.c
>> index add66236215c..b8c0fcde9bd7 100644
>> --- a/drivers/pci/host-bridge.c
>> +++ b/drivers/pci/host-bridge.c
>> @@ -22,6 +22,7 @@ struct pci_host_bridge *pci_find_host_bridge(struct pci_bus *bus)
>>  
>>  	return to_pci_host_bridge(root_bus->bridge);
>>  }
>> +EXPORT_SYMBOL_GPL(pci_find_host_bridge);
>>  
>>  struct device *pci_get_host_bridge_device(struct pci_dev *dev)
>>  {
>> -- 
>> 2.1.4
>>

Re: [PATCH V3 2/7] PCI: Export pci_find_host_bridge()

[Bjorn Helgaas]

On Fri, Dec 08, 2017 at 02:07:54PM +0530, Manikanta Maddireddy wrote:
> 
> 
> On 06-Dec-17 1:34 AM, Bjorn Helgaas wrote:
> > On Fri, Dec 01, 2017 at 02:50:02PM +0530, Manikanta Maddireddy wrote:
> >> PCI subsystem pass pci_bus pointer to pci_ops callback functions, Tegra
> > 
> > s/PCI subsystem pass/The PCI subsystem passes a/
> > s/, Tegra/.  The Tegra/
> > 
> >> host driver use pci_find_host_bridge() to get pci_host_bridge from pci_bus.
> > 
> > s/use/uses/
> > 
> >> Export pci_find_host_bridge() to allow Tegra PCIe driver to be compiled as
> >> loadable kernel module.
> > 
> > s/allow Tegra/allow the Tegra/
> > s/loadable/a loadable/
> > 
> > But why do you need pci_find_host_bridge() at all?  Most drivers use
> > the pci_bus.sysdata pointer for this purpose, e.g., see db271747a04d
> > ("PCI: mediatek: Use bus->sysdata to get host private data")
> 
> I will send a patch to use bus->sysdata instead of pci_find_host_bridge().

That would be excellent!  Thank you!

Bjorn
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[PATCH V3 4/7] PCI: tegra: Free resources on probe failure

[Manikanta Maddireddy]

tegra_pcie_probe() can fail in multiple instances, this patch takes care
of freeing the resources which are allocated before probe fail.

Signed-off-by: Manikanta Maddireddy <mmaddireddy-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
---
V2:
* no change in this patch
V3:
* change 'if check' to 'legacy_phy is true' for tegra_pcie_phys_put_legacy()
* commit log correction

 drivers/pci/host/pci-tegra.c | 100 ++++++++++++++++++++++++++++++++++++-------
 1 file changed, 84 insertions(+), 16 deletions(-)

diff --git a/drivers/pci/host/pci-tegra.c b/drivers/pci/host/pci-tegra.c
index 2a108c798846..36795b34d996 100644
--- a/drivers/pci/host/pci-tegra.c
+++ b/drivers/pci/host/pci-tegra.c
@@ -701,14 +701,25 @@ static int tegra_pcie_request_resources(struct tegra_pcie *pcie)
 	pci_add_resource(windows, &pcie->busn);
 
 	err = devm_request_pci_bus_resources(dev, windows);
-	if (err < 0)
+	if (err < 0) {
+		pci_free_resource_list(windows);
 		return err;
+	}
 
 	pci_remap_iospace(&pcie->pio, pcie->io.start);
 
 	return 0;
 }
 
+static void tegra_pcie_free_resources(struct tegra_pcie *pcie)
+{
+	struct pci_host_bridge *host = pci_host_bridge_from_priv(pcie);
+	struct list_head *windows = &host->windows;
+
+	pci_unmap_iospace(&pcie->pio);
+	pci_free_resource_list(windows);
+}
+
 static int tegra_pcie_map_irq(const struct pci_dev *pdev, u8 slot, u8 pin)
 {
 	struct pci_host_bridge *host = pci_find_host_bridge(pdev->bus);
@@ -1109,29 +1120,40 @@ static int tegra_pcie_enable_controller(struct tegra_pcie *pcie)
 	return 0;
 }
 
-static void tegra_pcie_power_off(struct tegra_pcie *pcie)
+static void tegra_pcie_disable_controller(struct tegra_pcie *pcie)
 {
 	struct device *dev = pcie->dev;
 	const struct tegra_pcie_soc *soc = pcie->soc;
 	int err;
 
-	/* TODO: disable and unprepare clocks? */
-
 	if (soc->program_uphy) {
 		err = tegra_pcie_phy_power_off(pcie);
 		if (err < 0)
 			dev_err(dev, "failed to power off PHY(s): %d\n", err);
 	}
+}
+
+static void tegra_pcie_power_off(struct tegra_pcie *pcie)
+{
+	struct device *dev = pcie->dev;
+	const struct tegra_pcie_soc *soc = pcie->soc;
+	int err;
 
 	reset_control_assert(pcie->afi_rst);
 	reset_control_assert(pcie->pex_rst);
 
-	if (!dev->pm_domain)
-		tegra_powergate_power_off(TEGRA_POWERGATE_PCIE);
+	clk_disable_unprepare(pcie->pll_e);
+	if (soc->has_cml_clk)
+		clk_disable_unprepare(pcie->cml_clk);
+	clk_disable_unprepare(pcie->afi_clk);
+	clk_disable_unprepare(pcie->pex_clk);
 
 	err = regulator_bulk_disable(pcie->num_supplies, pcie->supplies);
 	if (err < 0)
 		dev_warn(dev, "failed to disable regulators: %d\n", err);
+
+	if (!dev->pm_domain)
+		tegra_powergate_power_off(TEGRA_POWERGATE_PCIE);
 }
 
 static int tegra_pcie_power_on(struct tegra_pcie *pcie)
@@ -1262,6 +1284,15 @@ static int tegra_pcie_phys_get_legacy(struct tegra_pcie *pcie)
 	return 0;
 }
 
+static void tegra_pcie_phys_put_legacy(struct tegra_pcie *pcie)
+{
+	int err;
+
+	err = phy_exit(pcie->phy);
+	if (err < 0)
+		dev_err(pcie->dev, "failed to teardown PHY: %d\n", err);
+}
+
 static struct phy *devm_of_phy_optional_get_index(struct device *dev,
 						  struct device_node *np,
 						  const char *consumer,
@@ -1315,6 +1346,19 @@ static int tegra_pcie_port_get_phys(struct tegra_pcie_port *port)
 	return 0;
 }
 
+static void tegra_pcie_port_put_phys(struct tegra_pcie_port *port)
+{
+	struct device *dev = port->pcie->dev;
+	unsigned int i;
+	int err;
+
+	for (i = 0; i < port->lanes; i++) {
+		err = phy_exit(port->phys[i]);
+		if (err < 0)
+			dev_err(dev, "failed to teardown PHY#%u: %d\n", i, err);
+	}
+}
+
 static int tegra_pcie_phys_get(struct tegra_pcie *pcie)
 {
 	const struct tegra_pcie_soc *soc = pcie->soc;
@@ -1334,6 +1378,17 @@ static int tegra_pcie_phys_get(struct tegra_pcie *pcie)
 	return 0;
 }
 
+static void tegra_pcie_phys_put(struct tegra_pcie *pcie)
+{
+	struct tegra_pcie_port *port;
+
+	if (pcie->legacy_phy)
+		tegra_pcie_phys_put_legacy(pcie);
+
+	list_for_each_entry(port, &pcie->ports, list)
+		tegra_pcie_port_put_phys(port);
+}
+
 static int tegra_pcie_get_resources(struct tegra_pcie *pcie)
 {
 	struct device *dev = pcie->dev;
@@ -1366,7 +1421,7 @@ static int tegra_pcie_get_resources(struct tegra_pcie *pcie)
 	err = tegra_pcie_power_on(pcie);
 	if (err) {
 		dev_err(dev, "failed to power up: %d\n", err);
-		return err;
+		goto phys_put;
 	}
 
 	pads = platform_get_resource_byname(pdev, IORESOURCE_MEM, "pads");
@@ -1424,25 +1479,23 @@ static int tegra_pcie_get_resources(struct tegra_pcie *pcie)
 
 poweroff:
 	tegra_pcie_power_off(pcie);
+phys_put:
+	if (soc->program_uphy)
+		tegra_pcie_phys_put(pcie);
 	return err;
 }
 
 static int tegra_pcie_put_resources(struct tegra_pcie *pcie)
 {
-	struct device *dev = pcie->dev;
 	const struct tegra_pcie_soc *soc = pcie->soc;
-	int err;
 
 	if (pcie->irq > 0)
 		free_irq(pcie->irq, pcie);
 
 	tegra_pcie_power_off(pcie);
 
-	if (soc->program_uphy) {
-		err = phy_exit(pcie->phy);
-		if (err < 0)
-			dev_err(dev, "failed to teardown PHY: %d\n", err);
-	}
+	if (soc->program_uphy)
+		tegra_pcie_phys_put(pcie);
 
 	return 0;
 }
@@ -2371,6 +2424,16 @@ static void tegra_pcie_enable_ports(struct tegra_pcie *pcie)
 	}
 }
 
+static void tegra_pcie_disable_ports(struct tegra_pcie *pcie)
+{
+	struct tegra_pcie_port *port, *tmp;
+
+	reset_control_assert(pcie->pcie_xrst);
+
+	list_for_each_entry_safe(port, tmp, &pcie->ports, list)
+		tegra_pcie_port_disable(port);
+}
+
 static void tegra_pcie_change_link_speed(struct tegra_pcie *pcie,
 					 struct pci_dev *pci_dev)
 {
@@ -2691,7 +2754,7 @@ static int tegra_pcie_probe(struct platform_device *pdev)
 
 	err = tegra_pcie_request_resources(pcie);
 	if (err)
-		goto put_resources;
+		goto disable_controller;
 
 	/* setup the AFI address translations */
 	tegra_pcie_setup_translations(pcie);
@@ -2700,7 +2763,7 @@ static int tegra_pcie_probe(struct platform_device *pdev)
 		err = tegra_pcie_enable_msi(pcie);
 		if (err < 0) {
 			dev_err(dev, "failed to enable MSI support: %d\n", err);
-			goto put_resources;
+			goto free_resources;
 		}
 	}
 
@@ -2740,6 +2803,11 @@ static int tegra_pcie_probe(struct platform_device *pdev)
 disable_msi:
 	if (IS_ENABLED(CONFIG_PCI_MSI))
 		tegra_pcie_disable_msi(pcie);
+	tegra_pcie_disable_ports(pcie);
+free_resources:
+	tegra_pcie_free_resources(pcie);
+disable_controller:
+	tegra_pcie_disable_controller(pcie);
 put_resources:
 	tegra_pcie_put_resources(pcie);
 	return err;
-- 
2.1.4

[PATCH V3 5/7] PCI: tegra: Add loadable kernel module support

[Manikanta Maddireddy]

Implement remove callback function for Tegra PCIe driver to add
loadable kernel module support. Change PCI_TEGRA config to tristate to
allow pci-tegra driver to be build as a module.

Signed-off-by: Manikanta Maddireddy <mmaddireddy-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
---
V2:
* no change in this patch
V3:
* use tegra_pcie_debugfs_exit() helper function in tegra_pcie_debugfs_init()

 drivers/pci/host/Kconfig     |  2 +-
 drivers/pci/host/pci-tegra.c | 34 +++++++++++++++++++++++++++++++---
 2 files changed, 32 insertions(+), 4 deletions(-)

diff --git a/drivers/pci/host/Kconfig b/drivers/pci/host/Kconfig
index 38d12980db0f..6fd2a5937804 100644
--- a/drivers/pci/host/Kconfig
+++ b/drivers/pci/host/Kconfig
@@ -34,7 +34,7 @@ config PCI_FTPCI100
 	default ARCH_GEMINI
 
 config PCI_TEGRA
-	bool "NVIDIA Tegra PCIe controller"
+	tristate "NVIDIA Tegra PCIe controller"
 	depends on ARCH_TEGRA
 	help
 	  Say Y here if you want support for the PCIe host controller found
diff --git a/drivers/pci/host/pci-tegra.c b/drivers/pci/host/pci-tegra.c
index 36795b34d996..2c13f43e8450 100644
--- a/drivers/pci/host/pci-tegra.c
+++ b/drivers/pci/host/pci-tegra.c
@@ -35,6 +35,7 @@
 #include <linux/irqdomain.h>
 #include <linux/kernel.h>
 #include <linux/init.h>
+#include <linux/module.h>
 #include <linux/msi.h>
 #include <linux/of_address.h>
 #include <linux/of_pci.h>
@@ -2697,6 +2698,12 @@ static const struct file_operations tegra_pcie_ports_ops = {
 	.release = seq_release,
 };
 
+static void tegra_pcie_debugfs_exit(struct tegra_pcie *pcie)
+{
+	debugfs_remove_recursive(pcie->debugfs);
+	pcie->debugfs = NULL;
+}
+
 static int tegra_pcie_debugfs_init(struct tegra_pcie *pcie)
 {
 	struct dentry *file;
@@ -2713,8 +2720,7 @@ static int tegra_pcie_debugfs_init(struct tegra_pcie *pcie)
 	return 0;
 
 remove:
-	debugfs_remove_recursive(pcie->debugfs);
-	pcie->debugfs = NULL;
+	tegra_pcie_debugfs_exit(pcie);
 	return -ENOMEM;
 }
 
@@ -2732,6 +2738,7 @@ static int tegra_pcie_probe(struct platform_device *pdev)
 		return -ENOMEM;
 
 	pcie = pci_host_bridge_priv(host);
+	platform_set_drvdata(pdev, pcie);
 
 	pcie->soc = of_device_get_match_data(dev);
 	INIT_LIST_HEAD(&pcie->buses);
@@ -2813,6 +2820,25 @@ static int tegra_pcie_probe(struct platform_device *pdev)
 	return err;
 }
 
+static int tegra_pcie_remove(struct platform_device *pdev)
+{
+	struct tegra_pcie *pcie = platform_get_drvdata(pdev);
+	struct pci_host_bridge *host = pci_host_bridge_from_priv(pcie);
+
+	if (IS_ENABLED(CONFIG_DEBUG_FS))
+		tegra_pcie_debugfs_exit(pcie);
+	pci_stop_root_bus(host->bus);
+	pci_remove_root_bus(host->bus);
+	if (IS_ENABLED(CONFIG_PCI_MSI))
+		tegra_pcie_disable_msi(pcie);
+	tegra_pcie_disable_ports(pcie);
+	tegra_pcie_free_resources(pcie);
+	tegra_pcie_disable_controller(pcie);
+	tegra_pcie_put_resources(pcie);
+
+	return 0;
+}
+
 static struct platform_driver tegra_pcie_driver = {
 	.driver = {
 		.name = "tegra-pcie",
@@ -2820,5 +2846,7 @@ static struct platform_driver tegra_pcie_driver = {
 		.suppress_bind_attrs = true,
 	},
 	.probe = tegra_pcie_probe,
+	.remove = tegra_pcie_remove,
 };
-builtin_platform_driver(tegra_pcie_driver);
+module_platform_driver(tegra_pcie_driver);
+MODULE_LICENSE("GPL");
-- 
2.1.4

[PATCH V3 7/7] PCI: tegra: Add power management support

[Manikanta Maddireddy]

Tegra186 powergate driver is implemented as power domain driver, power
partition ungate/gate are registered as power_on/power_off callback
functions. There are no direct functions to power gate/ungate host
controller in Tegra186. Host controller driver should add "power-domains"
property in device tree and implement runtime suspend and resume
callback functons. Power gate and ungate is taken care by power domain
driver when host controller driver calls pm_runtime_put_sync and
pm_runtime_get_sync respectively.

Register suspend_noirq & resume_noirq callback functions to allow PCIe to
come up after resume from RAM. Both runtime and noirq pm ops share same
callback functions.

Signed-off-by: Manikanta Maddireddy <mmaddireddy-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
---
V2:
* no change in this patch
V3:
* no change in this patch

 drivers/pci/host/pci-tegra.c | 174 ++++++++++++++++++++++++++-----------------
 1 file changed, 106 insertions(+), 68 deletions(-)

diff --git a/drivers/pci/host/pci-tegra.c b/drivers/pci/host/pci-tegra.c
index bc532c0fd04f..30af1bf5620e 100644
--- a/drivers/pci/host/pci-tegra.c
+++ b/drivers/pci/host/pci-tegra.c
@@ -1425,31 +1425,25 @@ static int tegra_pcie_get_resources(struct tegra_pcie *pcie)
 		}
 	}
 
-	err = tegra_pcie_power_on(pcie);
-	if (err) {
-		dev_err(dev, "failed to power up: %d\n", err);
-		goto phys_put;
-	}
-
 	pads = platform_get_resource_byname(pdev, IORESOURCE_MEM, "pads");
 	pcie->pads = devm_ioremap_resource(dev, pads);
 	if (IS_ERR(pcie->pads)) {
 		err = PTR_ERR(pcie->pads);
-		goto poweroff;
+		goto phys_put;
 	}
 
 	afi = platform_get_resource_byname(pdev, IORESOURCE_MEM, "afi");
 	pcie->afi = devm_ioremap_resource(dev, afi);
 	if (IS_ERR(pcie->afi)) {
 		err = PTR_ERR(pcie->afi);
-		goto poweroff;
+		goto phys_put;
 	}
 
 	/* request configuration space, but remap later, on demand */
 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "cs");
 	if (!res) {
 		err = -EADDRNOTAVAIL;
-		goto poweroff;
+		goto phys_put;
 	}
 
 	axi_addr = pcie->soc->use_4k_conf_space ?
@@ -1457,21 +1451,21 @@ static int tegra_pcie_get_resources(struct tegra_pcie *pcie)
 	pcie->cs = devm_request_mem_region(dev, axi_addr, SZ_4K, res->name);
 	if (!pcie->cs) {
 		err = -EADDRNOTAVAIL;
-		goto poweroff;
+		goto phys_put;
 	}
 
 	pcie->cfg_va_base = devm_ioremap(dev, pcie->cs->start, SZ_4K);
 	if (!pcie->cfg_va_base) {
 		dev_err(pcie->dev, "failed to ioremap config space\n");
 		err = -EADDRNOTAVAIL;
-		goto poweroff;
+		goto phys_put;
 	}
 
 	/* request interrupt */
 	err = platform_get_irq_byname(pdev, "intr");
 	if (err < 0) {
 		dev_err(dev, "failed to get IRQ: %d\n", err);
-		goto poweroff;
+		goto phys_put;
 	}
 
 	pcie->irq = err;
@@ -1479,13 +1473,11 @@ static int tegra_pcie_get_resources(struct tegra_pcie *pcie)
 	err = request_irq(pcie->irq, tegra_pcie_isr, IRQF_SHARED, "PCIE", pcie);
 	if (err) {
 		dev_err(dev, "failed to register IRQ: %d\n", err);
-		goto poweroff;
+		goto phys_put;
 	}
 
 	return 0;
 
-poweroff:
-	tegra_pcie_power_off(pcie);
 phys_put:
 	if (soc->program_uphy)
 		tegra_pcie_phys_put(pcie);
@@ -1499,8 +1491,6 @@ static int tegra_pcie_put_resources(struct tegra_pcie *pcie)
 	if (pcie->irq > 0)
 		free_irq(pcie->irq, pcie);
 
-	tegra_pcie_power_off(pcie);
-
 	if (soc->program_uphy)
 		tegra_pcie_phys_put(pcie);
 
@@ -1678,37 +1668,41 @@ static int tegra_pcie_enable_msi(struct tegra_pcie *pcie)
 	int err;
 	u32 reg;
 
-	mutex_init(&msi->lock);
+	if (!msi->phys) {
+		mutex_init(&msi->lock);
 
-	msi->chip.dev = dev;
-	msi->chip.setup_irq = tegra_msi_setup_irq;
-	msi->chip.teardown_irq = tegra_msi_teardown_irq;
+		msi->chip.dev = dev;
+		msi->chip.setup_irq = tegra_msi_setup_irq;
+		msi->chip.teardown_irq = tegra_msi_teardown_irq;
 
-	msi->domain = irq_domain_add_linear(dev->of_node, INT_PCI_MSI_NR,
-					    &msi_domain_ops, &msi->chip);
-	if (!msi->domain) {
-		dev_err(dev, "failed to create IRQ domain\n");
-		return -ENOMEM;
-	}
+		msi->domain = irq_domain_add_linear(dev->of_node,
+						    INT_PCI_MSI_NR,
+						    &msi_domain_ops,
+						    &msi->chip);
+		if (!msi->domain) {
+			dev_err(dev, "failed to create IRQ domain\n");
+			return -ENOMEM;
+		}
 
-	err = platform_get_irq_byname(pdev, "msi");
-	if (err < 0) {
-		dev_err(dev, "failed to get IRQ: %d\n", err);
-		goto err;
-	}
+		err = platform_get_irq_byname(pdev, "msi");
+		if (err < 0) {
+			dev_err(dev, "failed to get IRQ: %d\n", err);
+			goto err;
+		}
 
-	msi->irq = err;
+		msi->irq = err;
 
-	err = request_irq(msi->irq, tegra_pcie_msi_irq, IRQF_NO_THREAD,
-			  tegra_msi_irq_chip.name, pcie);
-	if (err < 0) {
-		dev_err(dev, "failed to request IRQ: %d\n", err);
-		goto err;
-	}
+		err = request_irq(msi->irq, tegra_pcie_msi_irq, IRQF_NO_THREAD,
+				  tegra_msi_irq_chip.name, pcie);
+		if (err < 0) {
+			dev_err(dev, "failed to request IRQ: %d\n", err);
+			goto err;
+		}
 
-	/* setup AFI/FPCI range */
-	msi->pages = __get_free_pages(GFP_KERNEL, 0);
-	msi->phys = virt_to_phys((void *)msi->pages);
+		/* setup AFI/FPCI range */
+		msi->pages = __get_free_pages(GFP_KERNEL, 0);
+		msi->phys = virt_to_phys((void *)msi->pages);
+	}
 
 	afi_writel(pcie, msi->phys >> soc->msi_base_shift, AFI_MSI_FPCI_BAR_ST);
 	afi_writel(pcie, msi->phys, AFI_MSI_AXI_BAR_ST);
@@ -2796,26 +2790,16 @@ static int tegra_pcie_probe(struct platform_device *pdev)
 		return err;
 	}
 
-	err = tegra_pcie_enable_controller(pcie);
-	if (err)
+	pm_runtime_enable(pcie->dev);
+	err = pm_runtime_get_sync(pcie->dev);
+	if (err) {
+		dev_err(dev, "fail to enable pcie controller: %d\n", err);
 		goto put_resources;
+	}
 
 	err = tegra_pcie_request_resources(pcie);
 	if (err)
-		goto disable_controller;
-
-	/* setup the AFI address translations */
-	tegra_pcie_setup_translations(pcie);
-
-	if (IS_ENABLED(CONFIG_PCI_MSI)) {
-		err = tegra_pcie_enable_msi(pcie);
-		if (err < 0) {
-			dev_err(dev, "failed to enable MSI support: %d\n", err);
-			goto free_resources;
-		}
-	}
-
-	tegra_pcie_enable_ports(pcie);
+		goto pm_runtime_put;
 
 	host->busnr = pcie->busn.start;
 	host->dev.parent = &pdev->dev;
@@ -2826,7 +2810,7 @@ static int tegra_pcie_probe(struct platform_device *pdev)
 	err = pci_scan_root_bus_bridge(host);
 	if (err < 0) {
 		dev_err(dev, "failed to register host: %d\n", err);
-		goto disable_msi;
+		goto free_resources;
 	}
 
 	pci_bus_size_bridges(host->bus);
@@ -2848,14 +2832,13 @@ static int tegra_pcie_probe(struct platform_device *pdev)
 
 	return 0;
 
-disable_msi:
-	if (IS_ENABLED(CONFIG_PCI_MSI))
-		tegra_pcie_disable_msi(pcie);
-	tegra_pcie_disable_ports(pcie);
 free_resources:
 	tegra_pcie_free_resources(pcie);
-disable_controller:
-	tegra_pcie_disable_controller(pcie);
+pm_runtime_put:
+	if (IS_ENABLED(CONFIG_PCI_MSI))
+		tegra_pcie_disable_msi(pcie);
+	pm_runtime_put_sync(pcie->dev);
+	pm_runtime_disable(pcie->dev);
 put_resources:
 	tegra_pcie_put_resources(pcie);
 	return err;
@@ -2865,7 +2848,6 @@ static int tegra_pcie_remove(struct platform_device *pdev)
 {
 	struct tegra_pcie *pcie = platform_get_drvdata(pdev);
 	struct pci_host_bridge *host = pci_host_bridge_from_priv(pcie);
-	struct tegra_pcie_port *port, *tmp;
 
 	if (IS_ENABLED(CONFIG_DEBUG_FS))
 		tegra_pcie_debugfs_exit(pcie);
@@ -2873,21 +2855,77 @@ static int tegra_pcie_remove(struct platform_device *pdev)
 	pci_remove_root_bus(host->bus);
 	if (IS_ENABLED(CONFIG_PCI_MSI))
 		tegra_pcie_disable_msi(pcie);
+	tegra_pcie_free_resources(pcie);
+	pm_runtime_put_sync(pcie->dev);
+	pm_runtime_disable(pcie->dev);
+	tegra_pcie_put_resources(pcie);
+
+	return 0;
+}
+
+static int tegra_pcie_pm_suspend(struct device *dev)
+{
+	struct tegra_pcie *pcie = dev_get_drvdata(dev);
+	struct tegra_pcie_port *port, *tmp;
+
 	list_for_each_entry_safe(port, tmp, &pcie->ports, list)
 		tegra_pcie_pme_turnoff(port);
 	tegra_pcie_disable_ports(pcie);
-	tegra_pcie_free_resources(pcie);
 	tegra_pcie_disable_controller(pcie);
-	tegra_pcie_put_resources(pcie);
+	tegra_pcie_power_off(pcie);
 
 	return 0;
 }
 
+static int tegra_pcie_pm_resume(struct device *dev)
+{
+	struct tegra_pcie *pcie = dev_get_drvdata(dev);
+	int err;
+
+	err = tegra_pcie_power_on(pcie);
+	if (err) {
+		dev_err(dev, "tegra pcie power on fail: %d\n", err);
+		return err;
+	}
+	err = tegra_pcie_enable_controller(pcie);
+	if (err) {
+		dev_err(dev, "tegra pcie controller enable fail: %d\n", err);
+		goto poweroff;
+	}
+	tegra_pcie_setup_translations(pcie);
+
+	if (IS_ENABLED(CONFIG_PCI_MSI)) {
+		err = tegra_pcie_enable_msi(pcie);
+		if (err < 0) {
+			dev_err(dev, "failed to enable MSI support: %d\n", err);
+			goto disable_controller;
+		}
+	}
+
+	tegra_pcie_enable_ports(pcie);
+
+	return 0;
+
+disable_controller:
+	tegra_pcie_disable_controller(pcie);
+poweroff:
+	tegra_pcie_power_off(pcie);
+
+	return err;
+}
+
+static const struct dev_pm_ops tegra_pcie_pm_ops = {
+	SET_RUNTIME_PM_OPS(tegra_pcie_pm_suspend, tegra_pcie_pm_resume, NULL)
+	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(tegra_pcie_pm_suspend,
+				      tegra_pcie_pm_resume)
+};
+
 static struct platform_driver tegra_pcie_driver = {
 	.driver = {
 		.name = "tegra-pcie",
 		.of_match_table = tegra_pcie_of_match,
 		.suppress_bind_attrs = true,
+		.pm = &tegra_pcie_pm_ops,
 	},
 	.probe = tegra_pcie_probe,
 	.remove = tegra_pcie_remove,
-- 
2.1.4

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Re: [PATCH V3 0/7] Add loadable kernel module and power management support

[Lorenzo Pieralisi]

On Fri, Dec 01, 2017 at 02:50:00PM +0530, Manikanta Maddireddy wrote:
> This series of patches add loadable kernel module and power management
> support to Tegra PCIe host controller driver.
> 
> These patches are tested on Jetson TK1, TX1 and TX2 platforms, following
> are the verification details.
> 	- Multiple module insert & remove
> 	- PCIe device functionality after module insert
> 	- Free clock, resets, regulators, powergate, iomem and interrupt
> 	resources after module remove
> 	- PCIe device functionality after resume from RAM
> 
> Tegra PCIe host controller driver is using ioremap_page_range() which is
> not exported. This is switched with devm_ioremap() in the series
> 'https://patchwork.ozlabs.org/project/linux-tegra/list/?series=9907'.
> 
> V2: PM QoS fix is dropped in V2 from this series because the fix is
> incorporated in latest 'commit 0759e80b84e3 ("PM / QoS: Fix device resume
> latency framework")'. Update commit message of few patches in V2.
> 
> V3: Patches to export irq_set_msi_desc() and tegra_cpuidle_pcie_irqs_in_use()
> are dropped based on review comments. These symbols will be addressed in
> next series. Remove PCI_REASSIGN_ALL_BUS flag for Tegra PCIe and took care
> of few other review comments.
> 
> Manikanta Maddireddy (7):
>   of: Export of_pci_range_to_resource()
>   PCI: Export pci_find_host_bridge()
>   PCI: tegra: Remove PCI_REASSIGN_ALL_BUS flag for Tegra PCIe
>   PCI: tegra: Free resources on probe failure
>   PCI: tegra: Add loadable kernel module support
>   PCI: tegra: Broadcast PME_Turn_Off message before link goes to L2
>   PCI: tegra: Add power management support
> 
>  drivers/of/address.c         |   1 +
>  drivers/pci/host-bridge.c    |   1 +
>  drivers/pci/host/Kconfig     |   2 +-
>  drivers/pci/host/pci-tegra.c | 331 +++++++++++++++++++++++++++++++++----------

Applied patches 1 and 2 to pci/tegra for v4.16.

Bjorn picked up patch 3, the rest of the series needs
Thierry's ACK.

Thanks !
Lorenzo
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[PATCH V3 6/7] PCI: tegra: Broadcast PME_Turn_Off message before link goes to L2

[Manikanta Maddireddy]

Per PCIe r3.0, sec 5.3.3.2.1, PCIe root port shoould broadcast PME_Turn_Off
message before PCIe link goes to L2. PME_Turn_Off broadcast mechanism is
implemented in AFI module. Each Tegra PCIe root port has its own
PME_Turn_Off and PME_TO_Ack bitmap in AFI_PME register, program this
register to broadcast PME_Turn_Off message.

Signed-off-by: Manikanta Maddireddy <mmaddireddy@nvidia.com>
---
V2:
* no change in this patch
V3:
* add PME bitmap in soc data instead of using compatible string
* replace while loop with readl_poll_timeout() for polling
* commit log correction

 drivers/pci/host/pci-tegra.c | 44 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 44 insertions(+)

diff --git a/drivers/pci/host/pci-tegra.c b/drivers/pci/host/pci-tegra.c
index 2c13f43e8450..bc532c0fd04f 100644
--- a/drivers/pci/host/pci-tegra.c
+++ b/drivers/pci/host/pci-tegra.c
@@ -31,6 +31,7 @@
 #include <linux/delay.h>
 #include <linux/export.h>
 #include <linux/interrupt.h>
+#include <linux/iopoll.h>
 #include <linux/irq.h>
 #include <linux/irqdomain.h>
 #include <linux/kernel.h>
@@ -155,6 +156,8 @@
 #define  AFI_INTR_EN_FPCI_TIMEOUT	(1 << 7)
 #define  AFI_INTR_EN_PRSNT_SENSE	(1 << 8)
 
+#define AFI_PCIE_PME		0xf0
+
 #define AFI_PCIE_CONFIG					0x0f8
 #define  AFI_PCIE_CONFIG_PCIE_DISABLE(x)		(1 << ((x) + 1))
 #define  AFI_PCIE_CONFIG_PCIE_DISABLE_ALL		0xe
@@ -315,6 +318,7 @@
 #define PADS_REFCLK_CFG_DRVI_SHIFT		12 /* 15:12 */
 
 #define LINK_RETRAIN_TIMEOUT 100000
+#define PME_ACK_TIMEOUT 10000
 
 struct tegra_msi {
 	struct msi_controller chip;
@@ -342,6 +346,8 @@ struct tegra_pcie_soc {
 	u32 rp_ectl_4_r2;
 	u32 rp_ectl_5_r2;
 	u32 rp_ectl_6_r2;
+	u8 pme_turnoff_bit[3];
+	u8 pme_ack_bit[3];
 	bool has_pex_clkreq_en;
 	bool has_pex_bias_ctrl;
 	bool has_intr_prsnt_sense;
@@ -1501,6 +1507,31 @@ static int tegra_pcie_put_resources(struct tegra_pcie *pcie)
 	return 0;
 }
 
+static void tegra_pcie_pme_turnoff(struct tegra_pcie_port *port)
+{
+	struct tegra_pcie *pcie = port->pcie;
+	const struct tegra_pcie_soc *soc = pcie->soc;
+	int err;
+	u32 val;
+
+	val = afi_readl(pcie, AFI_PCIE_PME);
+	val |= (0x1 << soc->pme_turnoff_bit[port->index]);
+	afi_writel(pcie, val, AFI_PCIE_PME);
+
+	err = readl_poll_timeout(pcie->afi + AFI_PCIE_PME, val,
+				 val & (0x1 << soc->pme_ack_bit[port->index]),
+				 1, PME_ACK_TIMEOUT);
+	if (err)
+		dev_err(pcie->dev, "PME Ack is not received on port: %d\n",
+			port->index);
+
+	usleep_range(10000, 11000);
+
+	val = afi_readl(pcie, AFI_PCIE_PME);
+	val &= ~(0x1 << soc->pme_turnoff_bit[port->index]);
+	afi_writel(pcie, val, AFI_PCIE_PME);
+}
+
 static int tegra_msi_alloc(struct tegra_msi *chip)
 {
 	int msi;
@@ -2477,6 +2508,8 @@ static const struct tegra_pcie_soc tegra20_pcie = {
 	.pads_pll_ctl = PADS_PLL_CTL_TEGRA20,
 	.tx_ref_sel = PADS_PLL_CTL_TXCLKREF_DIV10,
 	.pads_refclk_cfg0 = 0xfa5cfa5c,
+	.pme_turnoff_bit = {0, 8},
+	.pme_ack_bit = {5, 10},
 	.has_pex_clkreq_en = false,
 	.has_pex_bias_ctrl = false,
 	.has_intr_prsnt_sense = false,
@@ -2502,6 +2535,8 @@ static const struct tegra_pcie_soc tegra30_pcie = {
 	.tx_ref_sel = PADS_PLL_CTL_TXCLKREF_BUF_EN,
 	.pads_refclk_cfg0 = 0xfa5cfa5c,
 	.pads_refclk_cfg1 = 0xfa5cfa5c,
+	.pme_turnoff_bit = {0, 8, 16},
+	.pme_ack_bit = {5, 10, 18},
 	.has_pex_clkreq_en = true,
 	.has_pex_bias_ctrl = true,
 	.has_intr_prsnt_sense = true,
@@ -2526,6 +2561,8 @@ static const struct tegra_pcie_soc tegra124_pcie = {
 	.pads_pll_ctl = PADS_PLL_CTL_TEGRA30,
 	.tx_ref_sel = PADS_PLL_CTL_TXCLKREF_BUF_EN,
 	.pads_refclk_cfg0 = 0x44ac44ac,
+	.pme_turnoff_bit = {0, 8},
+	.pme_ack_bit = {5, 10},
 	.has_pex_clkreq_en = true,
 	.has_pex_bias_ctrl = true,
 	.has_intr_prsnt_sense = true,
@@ -2550,6 +2587,8 @@ static const struct tegra_pcie_soc tegra210_pcie = {
 	.pads_pll_ctl = PADS_PLL_CTL_TEGRA30,
 	.tx_ref_sel = PADS_PLL_CTL_TXCLKREF_BUF_EN,
 	.pads_refclk_cfg0 = 0x90b890b8,
+	.pme_turnoff_bit = {0, 8},
+	.pme_ack_bit = {5, 10},
 	.rp_ectl_2_r1 = 0x0000000f,
 	.rp_ectl_4_r1 = 0x00000067,
 	.rp_ectl_5_r1 = 0x55010000,
@@ -2583,6 +2622,8 @@ static const struct tegra_pcie_soc tegra186_pcie = {
 	.tx_ref_sel = PADS_PLL_CTL_TXCLKREF_BUF_EN,
 	.pads_refclk_cfg0 = 0x80b880b8,
 	.pads_refclk_cfg1 = 0x000480b8,
+	.pme_turnoff_bit = {0, 8, 12},
+	.pme_ack_bit = {5, 10, 14},
 	.has_pex_clkreq_en = true,
 	.has_pex_bias_ctrl = true,
 	.has_intr_prsnt_sense = true,
@@ -2824,6 +2865,7 @@ static int tegra_pcie_remove(struct platform_device *pdev)
 {
 	struct tegra_pcie *pcie = platform_get_drvdata(pdev);
 	struct pci_host_bridge *host = pci_host_bridge_from_priv(pcie);
+	struct tegra_pcie_port *port, *tmp;
 
 	if (IS_ENABLED(CONFIG_DEBUG_FS))
 		tegra_pcie_debugfs_exit(pcie);
@@ -2831,6 +2873,8 @@ static int tegra_pcie_remove(struct platform_device *pdev)
 	pci_remove_root_bus(host->bus);
 	if (IS_ENABLED(CONFIG_PCI_MSI))
 		tegra_pcie_disable_msi(pcie);
+	list_for_each_entry_safe(port, tmp, &pcie->ports, list)
+		tegra_pcie_pme_turnoff(port);
 	tegra_pcie_disable_ports(pcie);
 	tegra_pcie_free_resources(pcie);
 	tegra_pcie_disable_controller(pcie);
-- 
2.1.4