[PATCH 0/2] pci: generic: Add supports for ARM64

[PATCH 0/2] pci: generic: Add supports for ARM64

[Suravee Suthikulpanit]

This patch series modifies the current PCI generic host controller
to support both ARM32 and ARM64. It has been tested on AMD Seattle
platform with the following patch series:

1. Marc Zyngier's patch series (for MSI supports):
[PATCH v2 0/8] Introducing per-device MSI domain
(http://lwn.net/Articles/628872/)

2. Murali Karicheri's patch series: 
[PATCH v6 0/7] PCI: get DMA configuration from parent device
(http://www.spinics.net/lists/linux-pci/msg38699.html)

Change from RFC:

  * In [PATCH 1/2] (https://lkml.org/lkml/2014/9/28/150),
    avoid the ugly #ifdef now that dependencies of pci_sys_data
    and pci_hw are removed.

  * In [PATCH 2/2] (https://lkml.org/lkml/2014/9/28/151),
    move tarch-specific check for PCI_PROBE_ONLY into driver/pci/pci.c


Suravee Suthikulpanit (2):
  pci: generic: Use the pci_scan_root_bus instead of pci_common_init_dev
  PCI: Do not call pci_enable_resource when specifying PCI_PROBE_ONLY

 arch/arm/kernel/bios32.c            | 12 ------------
 drivers/pci/host/Kconfig            |  2 +-
 drivers/pci/host/pci-host-generic.c | 33 ++++++++++-----------------------
 drivers/pci/pci.c                   |  3 +++
 4 files changed, 14 insertions(+), 36 deletions(-)

-- 
2.1.0

[PATCH 1/2] pci: generic: Use the pci_scan_root_bus instead of pci_common_init_dev

[Suravee Suthikulpanit]

Replacing pci_common_init_dev with pci_scan_root_bus, and remove reference
to struct pci_sys_data and pci_hw, which is specific to ARM32. This allows
the PCI host generic driver to also usable in ARM64 architecture.

Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Catalin Marinas <Catalin.Marinas@arm.com>
Cc: Liviu Dudau <Liviu.Dudau@arm.com>
Signed-off-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>

---
 drivers/pci/host/Kconfig            |  2 +-
 drivers/pci/host/pci-host-generic.c | 33 ++++++++++-----------------------
 2 files changed, 11 insertions(+), 24 deletions(-)

diff --git a/drivers/pci/host/Kconfig b/drivers/pci/host/Kconfig
index c4b6568..739bab0 100644
--- a/drivers/pci/host/Kconfig
+++ b/drivers/pci/host/Kconfig
@@ -53,7 +53,7 @@ config PCI_RCAR_GEN2_PCIE
 
 config PCI_HOST_GENERIC
 	bool "Generic PCI host controller"
-	depends on ARM && OF
+	depends on (ARM||ARM64) && OF
 	help
 	  Say Y here if you want to support a simple generic PCI host
 	  controller, such as the one emulated by kvmtool.
diff --git a/drivers/pci/host/pci-host-generic.c b/drivers/pci/host/pci-host-generic.c
index 6eb1aa7..93f64e4 100644
--- a/drivers/pci/host/pci-host-generic.c
+++ b/drivers/pci/host/pci-host-generic.c
@@ -48,8 +48,7 @@ static void __iomem *gen_pci_map_cfg_bus_cam(struct pci_bus *bus,
 					     unsigned int devfn,
 					     int where)
 {
-	struct pci_sys_data *sys = bus->sysdata;
-	struct gen_pci *pci = sys->private_data;
+	struct gen_pci *pci = bus->sysdata;
 	resource_size_t idx = bus->number - pci->cfg.bus_range->start;
 
 	return pci->cfg.win[idx] + ((devfn << 8) | where);
@@ -64,8 +63,7 @@ static void __iomem *gen_pci_map_cfg_bus_ecam(struct pci_bus *bus,
 					      unsigned int devfn,
 					      int where)
 {
-	struct pci_sys_data *sys = bus->sysdata;
-	struct gen_pci *pci = sys->private_data;
+	struct gen_pci *pci = bus->sysdata;
 	resource_size_t idx = bus->number - pci->cfg.bus_range->start;
 
 	return pci->cfg.win[idx] + ((devfn << 12) | where);
@@ -80,8 +78,7 @@ static int gen_pci_config_read(struct pci_bus *bus, unsigned int devfn,
 				int where, int size, u32 *val)
 {
 	void __iomem *addr;
-	struct pci_sys_data *sys = bus->sysdata;
-	struct gen_pci *pci = sys->private_data;
+	struct gen_pci *pci = bus->sysdata;
 
 	addr = pci->cfg.ops->map_bus(bus, devfn, where);
 
@@ -103,8 +100,7 @@ static int gen_pci_config_write(struct pci_bus *bus, unsigned int devfn,
 				 int where, int size, u32 val)
 {
 	void __iomem *addr;
-	struct pci_sys_data *sys = bus->sysdata;
-	struct gen_pci *pci = sys->private_data;
+	struct gen_pci *pci = bus->sysdata;
 
 	addr = pci->cfg.ops->map_bus(bus, devfn, where);
 
@@ -244,13 +240,6 @@ static int gen_pci_parse_map_cfg_windows(struct gen_pci *pci)
 	return 0;
 }
 
-static int gen_pci_setup(int nr, struct pci_sys_data *sys)
-{
-	struct gen_pci *pci = sys->private_data;
-	list_splice_init(&pci->resources, &sys->resources);
-	return 1;
-}
-
 static int gen_pci_probe(struct platform_device *pdev)
 {
 	int err;
@@ -260,13 +249,6 @@ static int gen_pci_probe(struct platform_device *pdev)
 	struct device *dev = &pdev->dev;
 	struct device_node *np = dev->of_node;
 	struct gen_pci *pci = devm_kzalloc(dev, sizeof(*pci), GFP_KERNEL);
-	struct hw_pci hw = {
-		.nr_controllers	= 1,
-		.private_data	= (void **)&pci,
-		.setup		= gen_pci_setup,
-		.map_irq	= of_irq_parse_and_map_pci,
-		.ops		= &gen_pci_ops,
-	};
 
 	if (!pci)
 		return -ENOMEM;
@@ -303,7 +285,12 @@ static int gen_pci_probe(struct platform_device *pdev)
 		return err;
 	}
 
-	pci_common_init_dev(dev, &hw);
+	if (!pci_scan_root_bus(&pdev->dev, pci->cfg.bus_range->start,
+			       &gen_pci_ops, pci, &pci->resources)) {
+		dev_err(&pdev->dev, "failed to enable PCIe ports\n");
+		return -ENODEV;
+	}
+
 	return 0;
 }
 
-- 
2.1.0

[PATCH 2/2] PCI: Do not call pci_enable_resource when specifying PCI_PROBE_ONLY

[Suravee Suthikulpanit]

When using PCI_PROBE_ONLY, Linux does not assign resource to PCI devices.
This causes error when calling the pci_enable_resources function, and not
allowing driver to set the PCI_COMMAND_IO and PCI_COMMAND_MEMORY flag in
the config space of endpoint device since it checks if the resource parent
is set.

This patch adds the check in driver/pci/pci.c to avoid redundant
arch-specific code. For example, it was in arch/arm/kernel/bios32.c and
also needed in the arch/arm64/kernel/pci.c.

This should not affect other architecture since most of them either
override the weak version of pcibios_enable_device()
or does not set PCI_PROBE_ONLY.

Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Catalin Marinas <Catalin.Marinas@arm.com>
Cc: Liviu Dudau <Liviu.Dudau@arm.com>
Signed-off-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>

---
NOTE:
Alpha seems to be the only arch that dooes not define pcibios_enable_device()
and also set PCI_PROBE_ONLY flag. I am not sure if this would cause any issues.
I might need help testing on Alpha.

 arch/arm/kernel/bios32.c | 12 ------------
 drivers/pci/pci.c        |  3 +++
 2 files changed, 3 insertions(+), 12 deletions(-)

diff --git a/arch/arm/kernel/bios32.c b/arch/arm/kernel/bios32.c
index a4effd6..091f508 100644
--- a/arch/arm/kernel/bios32.c
+++ b/arch/arm/kernel/bios32.c
@@ -607,18 +607,6 @@ resource_size_t pcibios_align_resource(void *data, const struct resource *res,
 	return start;
 }
 
-/**
- * pcibios_enable_device - Enable I/O and memory.
- * @dev: PCI device to be enabled
- */
-int pcibios_enable_device(struct pci_dev *dev, int mask)
-{
-	if (pci_has_flag(PCI_PROBE_ONLY))
-		return 0;
-
-	return pci_enable_resources(dev, mask);
-}
-
 int pci_mmap_page_range(struct pci_dev *dev, struct vm_area_struct *vma,
 			enum pci_mmap_state mmap_state, int write_combine)
 {
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index e9d4fd8..1748f95 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -1187,6 +1187,9 @@ EXPORT_SYMBOL_GPL(pci_load_and_free_saved_state);
 
 int __weak pcibios_enable_device(struct pci_dev *dev, int bars)
 {
+	if (pci_has_flag(PCI_PROBE_ONLY))
+		return 0;
+
 	return pci_enable_resources(dev, bars);
 }
 
-- 
2.1.0

Re: [PATCH 1/2] pci: generic: Use the pci_scan_root_bus instead of pci_common_init_dev

[Lorenzo Pieralisi]

On Mon, Feb 09, 2015 at 03:22:29PM +0000, Suravee Suthikulpanit wrote:
> Replacing pci_common_init_dev with pci_scan_root_bus, and remove reference
> to struct pci_sys_data and pci_hw, which is specific to ARM32. This allows
> the PCI host generic driver to also usable in ARM64 architecture.
> 
> Cc: Bjorn Helgaas <bhelgaas@google.com>
> Cc: Arnd Bergmann <arnd@arndb.de>
> Cc: Will Deacon <will.deacon@arm.com>
> Cc: Marc Zyngier <marc.zyngier@arm.com>
> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
> Cc: Catalin Marinas <Catalin.Marinas@arm.com>
> Cc: Liviu Dudau <Liviu.Dudau@arm.com>
> Signed-off-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
> 
> ---
>  drivers/pci/host/Kconfig            |  2 +-
>  drivers/pci/host/pci-host-generic.c | 33 ++++++++++-----------------------
>  2 files changed, 11 insertions(+), 24 deletions(-)
> 
> diff --git a/drivers/pci/host/Kconfig b/drivers/pci/host/Kconfig
> index c4b6568..739bab0 100644
> --- a/drivers/pci/host/Kconfig
> +++ b/drivers/pci/host/Kconfig
> @@ -53,7 +53,7 @@ config PCI_RCAR_GEN2_PCIE
>  
>  config PCI_HOST_GENERIC
>  	bool "Generic PCI host controller"
> -	depends on ARM && OF
> +	depends on (ARM||ARM64) && OF
>  	help
>  	  Say Y here if you want to support a simple generic PCI host
>  	  controller, such as the one emulated by kvmtool.
> diff --git a/drivers/pci/host/pci-host-generic.c b/drivers/pci/host/pci-host-generic.c
> index 6eb1aa7..93f64e4 100644
> --- a/drivers/pci/host/pci-host-generic.c
> +++ b/drivers/pci/host/pci-host-generic.c
> @@ -48,8 +48,7 @@ static void __iomem *gen_pci_map_cfg_bus_cam(struct pci_bus *bus,
>  					     unsigned int devfn,
>  					     int where)
>  {
> -	struct pci_sys_data *sys = bus->sysdata;
> -	struct gen_pci *pci = sys->private_data;
> +	struct gen_pci *pci = bus->sysdata;
>  	resource_size_t idx = bus->number - pci->cfg.bus_range->start;
>  
>  	return pci->cfg.win[idx] + ((devfn << 8) | where);
> @@ -64,8 +63,7 @@ static void __iomem *gen_pci_map_cfg_bus_ecam(struct pci_bus *bus,
>  					      unsigned int devfn,
>  					      int where)
>  {
> -	struct pci_sys_data *sys = bus->sysdata;
> -	struct gen_pci *pci = sys->private_data;
> +	struct gen_pci *pci = bus->sysdata;
>  	resource_size_t idx = bus->number - pci->cfg.bus_range->start;
>  
>  	return pci->cfg.win[idx] + ((devfn << 12) | where);
> @@ -80,8 +78,7 @@ static int gen_pci_config_read(struct pci_bus *bus, unsigned int devfn,
>  				int where, int size, u32 *val)
>  {
>  	void __iomem *addr;
> -	struct pci_sys_data *sys = bus->sysdata;
> -	struct gen_pci *pci = sys->private_data;
> +	struct gen_pci *pci = bus->sysdata;
>  
>  	addr = pci->cfg.ops->map_bus(bus, devfn, where);
>  
> @@ -103,8 +100,7 @@ static int gen_pci_config_write(struct pci_bus *bus, unsigned int devfn,
>  				 int where, int size, u32 val)
>  {
>  	void __iomem *addr;
> -	struct pci_sys_data *sys = bus->sysdata;
> -	struct gen_pci *pci = sys->private_data;
> +	struct gen_pci *pci = bus->sysdata;
>  
>  	addr = pci->cfg.ops->map_bus(bus, devfn, where);
>  
> @@ -244,13 +240,6 @@ static int gen_pci_parse_map_cfg_windows(struct gen_pci *pci)
>  	return 0;
>  }
>  
> -static int gen_pci_setup(int nr, struct pci_sys_data *sys)
> -{
> -	struct gen_pci *pci = sys->private_data;
> -	list_splice_init(&pci->resources, &sys->resources);
> -	return 1;
> -}
> -
>  static int gen_pci_probe(struct platform_device *pdev)
>  {
>  	int err;
> @@ -260,13 +249,6 @@ static int gen_pci_probe(struct platform_device *pdev)
>  	struct device *dev = &pdev->dev;
>  	struct device_node *np = dev->of_node;
>  	struct gen_pci *pci = devm_kzalloc(dev, sizeof(*pci), GFP_KERNEL);
> -	struct hw_pci hw = {
> -		.nr_controllers	= 1,
> -		.private_data	= (void **)&pci,
> -		.setup		= gen_pci_setup,
> -		.map_irq	= of_irq_parse_and_map_pci,
> -		.ops		= &gen_pci_ops,
> -	};
>  
>  	if (!pci)
>  		return -ENOMEM;
> @@ -303,7 +285,12 @@ static int gen_pci_probe(struct platform_device *pdev)
>  		return err;
>  	}
>  
> -	pci_common_init_dev(dev, &hw);
> +	if (!pci_scan_root_bus(&pdev->dev, pci->cfg.bus_range->start,
> +			       &gen_pci_ops, pci, &pci->resources)) {
> +		dev_err(&pdev->dev, "failed to enable PCIe ports\n");
> +		return -ENODEV;
> +	}

We need to assign resources if !PCI_PROBE_ONLY. And to do that we can't
use pci_scan_root_bus() because it adds devices before resources can be
assigned.

Furthermore, the ARM32 pcibios_align_resource() implementation requires
pci_sys_data, so we _still_ rely on pci_common_init_dev to create one
for us.

There are patches in flight to change this behaviour, so for this
series to be applicable there is still some code to be merged first,
we are getting there, bear with us.

Lorenzo

> +
>  	return 0;
>  }
>  
> -- 
> 2.1.0
> 
>