ARM: PCI: bios32: replace panic with WARN messages on failures

On ARM PCI systems relying on the pcibios API to initialize PCI host controllers, the pcibios_msi_controller weak callback is used to look-up the msi_controller pointer, through pci_sys_data msi_ctrl pointer.

pci_sys_data is an ARM specific structure, which prevents using the same mechanism (so same PCI host controller drivers) on ARM64 systems.

Since the struct pci_bus already contains an msi_controller pointer and the kernel already uses it to look-up the msi controller, this patch converts ARM host controller and related pcibios/host bridges initialization routines so that the msi_controller pointer look-up can be carried out by PCI core code through the struct pci_bus msi pointer, removing the need for the arch specific pcibios_msi_controller callback and the related pci_sys_data msi_ctrl pointer.

ARM is the only arch relying on the pcibios_msi_controller() weak function, hence this patch removes the default weak implementation from PCI core code since it becomes of no use.

Signed-off-by Lorenzo Pieralisi <[email protected]>

Acked-by Marc Zyngier <[email protected]>

Cc Pratyush Anand <[email protected]>

Cc Arnd Bergmann <[email protected]>

Cc Jingoo Han <[email protected]>

Cc Bjorn Helgaas <[email protected]>

Cc Simon Horman <[email protected]>

Cc Russell King <[email protected]>

Cc Thomas Petazzoni <[email protected]>

Cc Thierry Reding <[email protected]>

Cc Michal Simek <[email protected]>

Cc Marc Zyngier <[email protected]>

---
v1->v2

- Added patch to replace panic statements with WARN
- Removed unused pcibios_msi_controller() and pci_msi_controller() from core code
- Dropped RFT status

v1: http://lists.infradead.org/pipermail/linux-arm-kernel/2015-July/356028.html

 arch/arm/include/asm/mach/pci.h    |  3 ---
 arch/arm/kernel/bios32.c           | 29 +++++++++++++----------------
 drivers/pci/host/pcie-designware.c |  9 +++++++--
 drivers/pci/host/pcie-xilinx.c     | 12 ++++++++++--
 drivers/pci/msi.c                  | 17 +----------------
 5 files changed, 31 insertions(+), 39 deletions(-)

drivers/pci/msi.c +0 -12

index f66be86..0d20142 100644
@@ -77,24 +77,9 @@ static void pci_msi_teardown_msi_irqs(struct pci_dev *dev)
 
 /* Arch hooks */
 
-struct msi_controller * __weak pcibios_msi_controller(struct pci_dev *dev)
-{
-	return NULL;
-}
-
-static struct msi_controller *pci_msi_controller(struct pci_dev *dev)
-{
-	struct msi_controller *msi_ctrl = dev->bus->msi;
-
-	if (msi_ctrl)
-		return msi_ctrl;
-

Quoted 48 lines · Lorenzo Pieralisi

On ARM PCI systems relying on the pcibios API to initialize PCI host controllers, the pcibios_msi_controller weak callback is used to look-up the msi_controller pointer, through pci_sys_data msi_ctrl pointer.

pci_sys_data is an ARM specific structure, which prevents using the same mechanism (so same PCI host controller drivers) on ARM64 systems.

Since the struct pci_bus already contains an msi_controller pointer and the kernel already uses it to look-up the msi controller, this patch converts ARM host controller and related pcibios/host bridges initialization routines so that the msi_controller pointer look-up can be carried out by PCI core code through the struct pci_bus msi pointer, removing the need for the arch specific pcibios_msi_controller callback and the related pci_sys_data msi_ctrl pointer.

ARM is the only arch relying on the pcibios_msi_controller() weak function, hence this patch removes the default weak implementation from PCI core code since it becomes of no use.

Signed-off-by Lorenzo Pieralisi <[email protected]>

Acked-by Marc Zyngier <[email protected]>

Cc Pratyush Anand <[email protected]>

Cc Arnd Bergmann <[email protected]>

Cc Jingoo Han <[email protected]>

Cc Bjorn Helgaas <[email protected]>

Cc Simon Horman <[email protected]>

Cc Russell King <[email protected]>

Cc Thomas Petazzoni <[email protected]>

Cc Thierry Reding <[email protected]>

Cc Michal Simek <[email protected]>

Cc Marc Zyngier <[email protected]>

---
v1->v2

- Added patch to replace panic statements with WARN
- Removed unused pcibios_msi_controller() and pci_msi_controller() from core code
- Dropped RFT status

v1: http://lists.infradead.org/pipermail/linux-arm-kernel/2015-July/356028.html

 arch/arm/include/asm/mach/pci.h    |  3 ---
 arch/arm/kernel/bios32.c           | 29 +++++++++++++----------------
 drivers/pci/host/pcie-designware.c |  9 +++++++--
 drivers/pci/host/pcie-xilinx.c     | 12 ++++++++++--
 drivers/pci/msi.c                  | 17 +----------------
 5 files changed, 31 insertions(+), 39 deletions(-)

[...]

Quoted 20 lines

drivers/pci/msi.c +0 -12

index f66be86..0d20142 100644
@@ -77,24 +77,9 @@ static void pci_msi_teardown_msi_irqs(struct pci_dev *dev)
 
 /* Arch hooks */
 
-struct msi_controller * __weak pcibios_msi_controller(struct pci_dev *dev)
-{
-	return NULL;
-}
-
-static struct msi_controller *pci_msi_controller(struct pci_dev *dev)
-{
-	struct msi_controller *msi_ctrl = dev->bus->msi;
-
-	if (msi_ctrl)
-		return msi_ctrl;
-

drivers/pci/msi.c static void pci_msi_teardown_msi_irqs(struct pci_dev *dev) · line 85

Quoted 10 lines

drivers/pci/msi.c +1 -4

-	return pcibios_msi_controller(dev);
-}
-
 int __weak arch_setup_msi_irq(struct pci_dev *dev, struct msi_desc *desc)
 {
-	struct msi_controller *chip = pci_msi_controller(dev);
+	struct msi_controller *chip = dev->bus->msi;
 	int err;
 
 	if (!chip || !chip->setup_irq)

Don't you have to go to the top level bus and get the ->msi pointer? Something like:

	for (bus = dev->bus; bus != NULL; bus = bus->parent)
		if (bus->msi)
			return bus->msi;

I have not been following this closely, so I may have missed some patches.

Quoted 88 lines · Jayachandran C.

Quoted 48 lines · Lorenzo Pieralisi

On ARM PCI systems relying on the pcibios API to initialize PCI host controllers, the pcibios_msi_controller weak callback is used to look-up the msi_controller pointer, through pci_sys_data msi_ctrl pointer.

pci_sys_data is an ARM specific structure, which prevents using the same mechanism (so same PCI host controller drivers) on ARM64 systems.

Since the struct pci_bus already contains an msi_controller pointer and the kernel already uses it to look-up the msi controller, this patch converts ARM host controller and related pcibios/host bridges initialization routines so that the msi_controller pointer look-up can be carried out by PCI core code through the struct pci_bus msi pointer, removing the need for the arch specific pcibios_msi_controller callback and the related pci_sys_data msi_ctrl pointer.

ARM is the only arch relying on the pcibios_msi_controller() weak function, hence this patch removes the default weak implementation from PCI core code since it becomes of no use.

Signed-off-by Lorenzo Pieralisi <[email protected]>

Acked-by Marc Zyngier <[email protected]>

Cc Pratyush Anand <[email protected]>

Cc Arnd Bergmann <[email protected]>

Cc Jingoo Han <[email protected]>

Cc Bjorn Helgaas <[email protected]>

Cc Simon Horman <[email protected]>

Cc Russell King <[email protected]>

Cc Thomas Petazzoni <[email protected]>

Cc Thierry Reding <[email protected]>

Cc Michal Simek <[email protected]>

Cc Marc Zyngier <[email protected]>

---
v1->v2

- Added patch to replace panic statements with WARN
- Removed unused pcibios_msi_controller() and pci_msi_controller() from core code
- Dropped RFT status

v1: http://lists.infradead.org/pipermail/linux-arm-kernel/2015-July/356028.html

 arch/arm/include/asm/mach/pci.h    |  3 ---
 arch/arm/kernel/bios32.c           | 29 +++++++++++++----------------
 drivers/pci/host/pcie-designware.c |  9 +++++++--
 drivers/pci/host/pcie-xilinx.c     | 12 ++++++++++--
 drivers/pci/msi.c                  | 17 +----------------
 5 files changed, 31 insertions(+), 39 deletions(-)

[...]

Quoted 20 lines

drivers/pci/msi.c +0 -12

index f66be86..0d20142 100644
@@ -77,24 +77,9 @@ static void pci_msi_teardown_msi_irqs(struct pci_dev *dev)
 
 /* Arch hooks */
 
-struct msi_controller * __weak pcibios_msi_controller(struct pci_dev *dev)
-{
-	return NULL;
-}
-
-static struct msi_controller *pci_msi_controller(struct pci_dev *dev)
-{
-	struct msi_controller *msi_ctrl = dev->bus->msi;
-
-	if (msi_ctrl)
-		return msi_ctrl;
-

drivers/pci/msi.c static void pci_msi_teardown_msi_irqs(struct pci_dev *dev) · line 85

Quoted 10 lines

drivers/pci/msi.c +1 -4

-	return pcibios_msi_controller(dev);
-}
-
 int __weak arch_setup_msi_irq(struct pci_dev *dev, struct msi_desc *desc)
 {
-	struct msi_controller *chip = pci_msi_controller(dev);
+	struct msi_controller *chip = dev->bus->msi;
 	int err;
 
 	if (!chip || !chip->setup_irq)

Don't you have to go to the top level bus and get the ->msi pointer? Something like:

	for (bus = dev->bus; bus != NULL; bus = bus->parent)
		if (bus->msi)
			return bus->msi;

Quoted 1 line

I have not been following this closely, so I may have missed some patches.

The msi pointer is initialized from parent to child in pci_alloc_child_bus(), so PCI core does that for us, that's my understanding.

It works the same as sysdata pointer, which is why pcibios_msi_controller works in the current kernel.

On a side note, are you able to prepare a new version of your set to enable the PCI generic host on ARM64 (and remove pci_sys_data and related ifdef CONFIG_ARM from it) ?

We are not far from removing the pci_sys_data dependency, if you can't prepare a new version of your series let me know I can do it on your behalf.

Quoted 89 lines · Lorenzo Pieralisi

Quoted 88 lines · Jayachandran C.

Quoted 48 lines · Lorenzo Pieralisi

On ARM PCI systems relying on the pcibios API to initialize PCI host controllers, the pcibios_msi_controller weak callback is used to look-up the msi_controller pointer, through pci_sys_data msi_ctrl pointer.

pci_sys_data is an ARM specific structure, which prevents using the same mechanism (so same PCI host controller drivers) on ARM64 systems.

Since the struct pci_bus already contains an msi_controller pointer and the kernel already uses it to look-up the msi controller, this patch converts ARM host controller and related pcibios/host bridges initialization routines so that the msi_controller pointer look-up can be carried out by PCI core code through the struct pci_bus msi pointer, removing the need for the arch specific pcibios_msi_controller callback and the related pci_sys_data msi_ctrl pointer.

ARM is the only arch relying on the pcibios_msi_controller() weak function, hence this patch removes the default weak implementation from PCI core code since it becomes of no use.

Signed-off-by Lorenzo Pieralisi <[email protected]>

Acked-by Marc Zyngier <[email protected]>

Cc Pratyush Anand <[email protected]>

Cc Arnd Bergmann <[email protected]>

Cc Jingoo Han <[email protected]>

Cc Bjorn Helgaas <[email protected]>

Cc Simon Horman <[email protected]>

Cc Russell King <[email protected]>

Cc Thomas Petazzoni <[email protected]>

Cc Thierry Reding <[email protected]>

Cc Michal Simek <[email protected]>

Cc Marc Zyngier <[email protected]>

---
v1->v2

- Added patch to replace panic statements with WARN
- Removed unused pcibios_msi_controller() and pci_msi_controller() from core code
- Dropped RFT status

v1: http://lists.infradead.org/pipermail/linux-arm-kernel/2015-July/356028.html

 arch/arm/include/asm/mach/pci.h    |  3 ---
 arch/arm/kernel/bios32.c           | 29 +++++++++++++----------------
 drivers/pci/host/pcie-designware.c |  9 +++++++--
 drivers/pci/host/pcie-xilinx.c     | 12 ++++++++++--
 drivers/pci/msi.c                  | 17 +----------------
 5 files changed, 31 insertions(+), 39 deletions(-)

[...]

Quoted 20 lines

drivers/pci/msi.c +0 -12

index f66be86..0d20142 100644
@@ -77,24 +77,9 @@ static void pci_msi_teardown_msi_irqs(struct pci_dev *dev)
 
 /* Arch hooks */
 
-struct msi_controller * __weak pcibios_msi_controller(struct pci_dev *dev)
-{
-	return NULL;
-}
-
-static struct msi_controller *pci_msi_controller(struct pci_dev *dev)
-{
-	struct msi_controller *msi_ctrl = dev->bus->msi;
-
-	if (msi_ctrl)
-		return msi_ctrl;
-

drivers/pci/msi.c static void pci_msi_teardown_msi_irqs(struct pci_dev *dev) · line 85

Quoted 10 lines

drivers/pci/msi.c +1 -4

-	return pcibios_msi_controller(dev);
-}
-
 int __weak arch_setup_msi_irq(struct pci_dev *dev, struct msi_desc *desc)
 {
-	struct msi_controller *chip = pci_msi_controller(dev);
+	struct msi_controller *chip = dev->bus->msi;
 	int err;
 
 	if (!chip || !chip->setup_irq)

Don't you have to go to the top level bus and get the ->msi pointer? Something like:

	for (bus = dev->bus; bus != NULL; bus = bus->parent)
		if (bus->msi)
			return bus->msi;

Quoted 8 lines

Quoted 1 line

I have not been following this closely, so I may have missed some patches.

The msi pointer is initialized from parent to child in pci_alloc_child_bus(), so PCI core does that for us, that's my understanding.

It works the same as sysdata pointer, which is why pcibios_msi_controller works in the current kernel.

Thanks.

Quoted 5 lines

On a side note, are you able to prepare a new version of your set to enable the PCI generic host on ARM64 (and remove pci_sys_data and related ifdef CONFIG_ARM from it) ?

Quoted 3 lines

We are not far from removing the pci_sys_data dependency, if you can't prepare a new version of your series let me know I can do it on your behalf.

I will post an updated patch with a minor fix. I will also add a patch for parsing msi-parent and setting ->msi on the root bus.

Quoted 89 lines · Lorenzo Pieralisi

Quoted 88 lines · Jayachandran C.

Quoted 48 lines · Lorenzo Pieralisi

On ARM PCI systems relying on the pcibios API to initialize PCI host controllers, the pcibios_msi_controller weak callback is used to look-up the msi_controller pointer, through pci_sys_data msi_ctrl pointer.

pci_sys_data is an ARM specific structure, which prevents using the same mechanism (so same PCI host controller drivers) on ARM64 systems.

Since the struct pci_bus already contains an msi_controller pointer and the kernel already uses it to look-up the msi controller, this patch converts ARM host controller and related pcibios/host bridges initialization routines so that the msi_controller pointer look-up can be carried out by PCI core code through the struct pci_bus msi pointer, removing the need for the arch specific pcibios_msi_controller callback and the related pci_sys_data msi_ctrl pointer.

ARM is the only arch relying on the pcibios_msi_controller() weak function, hence this patch removes the default weak implementation from PCI core code since it becomes of no use.

Signed-off-by Lorenzo Pieralisi <[email protected]>

Acked-by Marc Zyngier <[email protected]>

Cc Pratyush Anand <[email protected]>

Cc Arnd Bergmann <[email protected]>

Cc Jingoo Han <[email protected]>

Cc Bjorn Helgaas <[email protected]>

Cc Simon Horman <[email protected]>

Cc Russell King <[email protected]>

Cc Thomas Petazzoni <[email protected]>

Cc Thierry Reding <[email protected]>

Cc Michal Simek <[email protected]>

Cc Marc Zyngier <[email protected]>

---
v1->v2

- Added patch to replace panic statements with WARN
- Removed unused pcibios_msi_controller() and pci_msi_controller() from core code
- Dropped RFT status

v1: http://lists.infradead.org/pipermail/linux-arm-kernel/2015-July/356028.html

 arch/arm/include/asm/mach/pci.h    |  3 ---
 arch/arm/kernel/bios32.c           | 29 +++++++++++++----------------
 drivers/pci/host/pcie-designware.c |  9 +++++++--
 drivers/pci/host/pcie-xilinx.c     | 12 ++++++++++--
 drivers/pci/msi.c                  | 17 +----------------
 5 files changed, 31 insertions(+), 39 deletions(-)

[...]

Quoted 20 lines

drivers/pci/msi.c +0 -12

index f66be86..0d20142 100644
@@ -77,24 +77,9 @@ static void pci_msi_teardown_msi_irqs(struct pci_dev *dev)
 
 /* Arch hooks */
 
-struct msi_controller * __weak pcibios_msi_controller(struct pci_dev *dev)
-{
-	return NULL;
-}
-
-static struct msi_controller *pci_msi_controller(struct pci_dev *dev)
-{
-	struct msi_controller *msi_ctrl = dev->bus->msi;
-
-	if (msi_ctrl)
-		return msi_ctrl;
-

drivers/pci/msi.c static void pci_msi_teardown_msi_irqs(struct pci_dev *dev) · line 85

Quoted 10 lines

drivers/pci/msi.c +1 -4

-	return pcibios_msi_controller(dev);
-}
-
 int __weak arch_setup_msi_irq(struct pci_dev *dev, struct msi_desc *desc)
 {
-	struct msi_controller *chip = pci_msi_controller(dev);
+	struct msi_controller *chip = dev->bus->msi;
 	int err;
 
 	if (!chip || !chip->setup_irq)

Don't you have to go to the top level bus and get the ->msi pointer? Something like:

	for (bus = dev->bus; bus != NULL; bus = bus->parent)
		if (bus->msi)
			return bus->msi;

Quoted 8 lines

Quoted 1 line

I have not been following this closely, so I may have missed some patches.

The msi pointer is initialized from parent to child in pci_alloc_child_bus(), so PCI core does that for us, that's my understanding.

It works the same as sysdata pointer, which is why pcibios_msi_controller works in the current kernel.

Thanks.

Quoted 5 lines

On a side note, are you able to prepare a new version of your set to enable the PCI generic host on ARM64 (and remove pci_sys_data and related ifdef CONFIG_ARM from it) ?

Quoted 3 lines

We are not far from removing the pci_sys_data dependency, if you can't prepare a new version of your series let me know I can do it on your behalf.

I will post an updated patch with a minor fix. I will also add a patch for parsing msi-parent and setting ->msi on the root bus.

On ARM PCI systems relying on the pcibios API to initialize PCI host controllers, the pcibios_msi_controller weak callback is used to look-up the msi_controller pointer, through pci_sys_data msi_ctrl pointer.

pci_sys_data is an ARM specific structure, which prevents using the same mechanism (so same PCI host controller drivers) on ARM64 systems.

Since the struct pci_bus already contains an msi_controller pointer and the kernel already uses it to look-up the msi controller, this patch converts ARM host controller and related pcibios/host bridges initialization routines so that the msi_controller pointer look-up can be carried out by PCI core code through the struct pci_bus msi pointer, removing the need for the arch specific pcibios_msi_controller callback and the related pci_sys_data msi_ctrl pointer.

ARM is the only arch relying on the pcibios_msi_controller() weak function, hence this patch removes the default weak implementation from PCI core code since it becomes of no use.

Quoted 15 lines · Lorenzo Pieralisi

On ARM PCI systems relying on the pcibios API to initialize PCI host controllers, the pcibios_msi_controller weak callback is used to look-up the msi_controller pointer, through pci_sys_data msi_ctrl pointer.

pci_sys_data is an ARM specific structure, which prevents using the same mechanism (so same PCI host controller drivers) on ARM64 systems.

Since the struct pci_bus already contains an msi_controller pointer and the kernel already uses it to look-up the msi controller, this patch converts ARM host controller and related pcibios/host bridges initialization routines so that the msi_controller pointer look-up can be carried out by PCI core code through the struct pci_bus msi pointer, removing the need for the arch specific pcibios_msi_controller callback and the related pci_sys_data msi_ctrl pointer.

Quoted 3 lines

ARM is the only arch relying on the pcibios_msi_controller() weak function, hence this patch removes the default weak implementation from PCI core code since it becomes of no use.

You don't mention the change from using pci_scan_root_bus() to using pci_create_root_bus() here.

arch/arm/kernel/bios32.c static void pcibios_init_hw(struct device *parent, struct hw_pci *hw, · line 480

Quoted 7 lines

arch/arm/kernel/bios32.c +5 -2

-				sys->bus = pci_scan_root_bus(parent, sys->busnr,
-						hw->ops, sys, &sys->resources);
+			} else {
+				sys->bus = pci_create_root_bus(parent,
+							       sys->busnr,
+							       hw->ops, sys,
+							       &sys->resources);

By making this change, there is no nothing which will call pci_bus_insert_busn_res().

What about the 18 users of the ->scan method, at least IOP13xx appears to be MSI-enabled, though it's not clear whether it works with MSI.

This doesn't seem to be a good approach. Maybe having a version of pci_scan_root_bus() which takes the MSI data as an argument would be better than selectively copying pci_scan_root_bus() into the ARM code?

Quoted 3 lines · Russell King - ARM Linux

This doesn't seem to be a good approach. Maybe having a version of pci_scan_root_bus() which takes the MSI data as an argument would be better than selectively copying pci_scan_root_bus() into the ARM code?

I understand your point, let's try to find a fast way forward, we are stuck otherwise:

3) I patch pci_scan_root_bus() to pass the MSI pointer. I think that pcibios_msi_controller was added to avoid doing this, that function has already 5 parameters and it is a treewide change, I suspect Bjorn won't be happy about this at all.

Quoted 8 lines · Lorenzo Pieralisi

Quoted 3 lines · Russell King - ARM Linux

This doesn't seem to be a good approach. Maybe having a version of pci_scan_root_bus() which takes the MSI data as an argument would be better than selectively copying pci_scan_root_bus() into the ARM code?

I understand your point, let's try to find a fast way forward, we are stuck otherwise:

Quoted 4 lines

3) I patch pci_scan_root_bus() to pass the MSI pointer. I think that pcibios_msi_controller was added to avoid doing this, that function has already 5 parameters and it is a treewide change, I suspect Bjorn won't be happy about this at all.

Or you could use the suggestion I made in the paragraph you quoted above, which is a variation on your (3) without the down-sides of needing to change lots of callsites. Something like this (bios32.c is incomplete):

 arch/arm/kernel/bios32.c |  8 +++-----
 drivers/pci/probe.c      | 15 +++++++++++++--
 include/linux/pci.h      |  4 ++++
 3 files changed, 20 insertions(+), 7 deletions(-)

arch/arm/kernel/bios32.c +3 -5

index fcbbbb1b9e95..e4f7c0eb6c14 100644
@@ -462,9 +462,6 @@ static void pcibios_init_hw(struct device *parent, struct hw_pci *hw,
 		if (!sys)
 			panic("PCI: unable to allocate sys data!");
 
-#ifdef CONFIG_PCI_MSI
-		sys->msi_ctrl = hw->msi_ctrl;
-#endif
 		sys->busnr   = busnr;
 		sys->swizzle = hw->swizzle;
 		sys->map_irq = hw->map_irq;

@@ -486,8 +483,9 @@ static void pcibios_init_hw(struct device *parent, struct hw_pci *hw,
 			if (hw->scan)
 				sys->bus = hw->scan(nr, sys);
 			else
-				sys->bus = pci_scan_root_bus(parent, sys->busnr,
-						hw->ops, sys, &sys->resources);
+				sys->bus = pci_scan_root_bus_msi(parent,
+						sys->busnr, hw->ops, sys,
+						&sys->resources, hw->msi_ctrl);
 
 			if (!sys->bus)
 				panic("PCI: unable to scan bus!");

drivers/pci/probe.c +13 -2

index cefd636681b6..4915c6d9c22d 100644
@@ -2096,8 +2096,9 @@ void pci_bus_release_busn_res(struct pci_bus *b)
 			res, ret ? "can not be" : "is");
 }
 
-struct pci_bus *pci_scan_root_bus(struct device *parent, int bus,
-		struct pci_ops *ops, void *sysdata, struct list_head *resources)
+struct pci_bus *pci_scan_root_bus_msi(struct device *parent, int bus,
+		struct pci_ops *ops, void *sysdata,
+		struct list_head *resources, struct msi_controller *msi)
 {
 	struct resource_entry *window;
 	bool found = false;

@@ -2114,6 +2115,8 @@ struct pci_bus *pci_scan_root_bus(struct device *parent, int bus,
 	if (!b)
 		return NULL;
 
+	b->msi = msi;
+
 	if (!found) {
 		dev_info(&b->dev,
 		 "No busn resource found for root bus, will use [bus %02x-ff]\n",

@@ -2128,6 +2131,14 @@ struct pci_bus *pci_scan_root_bus(struct device *parent, int bus,
 
 	return b;
 }
+EXPORT_SYMBOL(pci_scan_root_bus_msi);
+
+struct pci_bus *pci_scan_root_bus(struct device *parent, int bus,
+		struct pci_ops *ops, void *sysdata, struct list_head *resources)
+{
+	return pci_scan_root_bus_msi(parent, bus, ops, sysdata, resources,
+				     NULL);
+}
 EXPORT_SYMBOL(pci_scan_root_bus);
 
 struct pci_bus *pci_scan_bus(int bus, struct pci_ops *ops,

include/linux/pci.h +4 -0

index 8a0321a8fb59..4d4f9d29fcc9 100644
@@ -787,6 +787,10 @@ struct pci_bus *pci_create_root_bus(struct device *parent, int bus,
 int pci_bus_insert_busn_res(struct pci_bus *b, int bus, int busmax);
 int pci_bus_update_busn_res_end(struct pci_bus *b, int busmax);
 void pci_bus_release_busn_res(struct pci_bus *b);
+struct pci_bus *pci_scan_root_bus_msi(struct device *parent, int bus,
+				      struct pci_ops *ops, void *sysdata,
+				      struct list_head *resources,
+				      struct msi_controller *msi);
 struct pci_bus *pci_scan_root_bus(struct device *parent, int bus,
 					     struct pci_ops *ops, void *sysdata,
 					     struct list_head *resources);

And it's probably a good idea to kill off the ifdef around this:

struct hw_pci {

#ifdef CONFIG_PCI_MSI
        struct msi_controller *msi_ctrl;

#endif

so that we can avoid ifdefs in random places in arch/arm code (as is the decision in the rest of PCI for this.)

Signature · 2 lines

FTTC broadband for 0.8mile line: currently at 10.5Mbps down 400kbps up
according to speedtest.net.

In the ARM PCI bios32 layer, failures to dynamically allocate pci_sys_data for a PCI bus, or a PCI bus scan failure have to be considered serious warnings but they should not trigger a system panic so that at least the system is given a chance to be debugged.

This patch replaces the panic statements with WARN() messages to improve error reporting in the ARM PCI bios32 layer.

Signed-off-by Lorenzo Pieralisi <[email protected]>

Cc Bjorn Helgaas <[email protected]>

Cc Russell King <[email protected]>

Cc Marc Zyngier <[email protected]>