diff mbox

[v4,1/3] PCI: generic: remove dependency on hw_pci

Message ID 1438721620-15493-1-git-send-email-jchandra@broadcom.com (mailing list archive)
State New, archived
Delegated to: Bjorn Helgaas
Headers show

Commit Message

Jayachandran C. Aug. 4, 2015, 8:53 p.m. UTC
The current code in pci-host-generic.c uses pci_common_init_dev()
from arm architecture to do some part of the PCI setup, and this
prevents it from being used with arm64 architecture.

The part of pci_common_init_dev() that is really needed by
pci-host-generic.c is very limited and can be done in the same
file without using hw_pci API of ARM. The ARM platform requires
a pci_sys_data as sysdata for the PCI bus, this can be handled by
setting up gen_pci to have a pci_sys_data variable as the first
element.

Signed-off-by: Jayachandran C <jchandra@broadcom.com>
Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Tested-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Tested-by: Pavel Fedin <p.fedin@samsung.com>
---
Here's v4 of the patchset.
v3-v4
 - Changes for comments by Lorenzo Pieralisi/Will Deacon
  - add PCI_REASSIGN_ALL_BUS flag if not probe only
  - split setup-irq.o into another patch
  - minor clean up of commit messages

v2-v3
 - rebase to 4.2-rc
 - fix PCI_PROBE_ONLY check before calling pcie configure
 - added a comment above sysdata
 - updated the commit message

v1->v2
 - Address comments from Arnd Bergmann and Lorenzo Pieralisi
    - move contents of gen_pci_init to gen_pci_probe
    - assign resources only when !probe_only
 - tested on ARM32 with qemu option -M virt

Notes:
 - passing a zeroed out pci_sys_data for ARM looks ok, but I haven't
   tested it on ARM.
 - tested it on ARM64 fast model
 - Any information on how this can be tested on arm is welcome.
 - There is only one ifdef, and that can be removed when arm64 gets
   a sysdata, or when arm loses its sysdata.
 drivers/pci/host/pci-host-generic.c | 55 ++++++++++++++++++++++++-------------
 1 file changed, 36 insertions(+), 19 deletions(-)

Comments

Bjorn Helgaas Aug. 4, 2015, 11:49 p.m. UTC | #1
On Wed, Aug 05, 2015 at 02:23:38AM +0530, Jayachandran C wrote:
> The current code in pci-host-generic.c uses pci_common_init_dev()
> from arm architecture to do some part of the PCI setup, and this
> prevents it from being used with arm64 architecture.
> 
> The part of pci_common_init_dev() that is really needed by
> pci-host-generic.c is very limited and can be done in the same
> file without using hw_pci API of ARM. The ARM platform requires
> a pci_sys_data as sysdata for the PCI bus, this can be handled by
> setting up gen_pci to have a pci_sys_data variable as the first
> element.
> 
> Signed-off-by: Jayachandran C <jchandra@broadcom.com>
> Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
> Tested-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
> Tested-by: Pavel Fedin <p.fedin@samsung.com>

I applied all three of these to my pci/enumeration branch for v4.3.

I made a few changes, the most important being to call
pcie_bus_configure_settings() before pci_bus_add_devices(), because drivers
may claim devices in pci_bus_add_devices(), and the PCI core shouldn't
touch devices after drivers claim them.

I dropped the acks and tested-by because of that change, but I'll happily
add them back if Lorenzo and Pavel confirm.  The patches are here if you
want to review/test them:

https://git.kernel.org/cgit/linux/kernel/git/helgaas/pci.git/log/?h=pci/enumeration

I'm sure the other patches on that branch will need some tweaks, too, so I
don't have any problem with updating these.

Bjorn
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Pavel Fedin Aug. 12, 2015, 7:11 a.m. UTC | #2
Hello!

> I dropped the acks and tested-by because of that change, but I'll happily
> add them back if Lorenzo and Pavel confirm.  

 Confirm.
 Tested-by: Pavel Fedin <p.fedin@samsung.com>

 I also added MSI support. Can i post it as patch on top of your branch?

Kind regards,
Pavel Fedin
Expert Engineer
Samsung Electronics Research center Russia

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Will Deacon Aug. 12, 2015, 9:04 a.m. UTC | #3
On Wed, Aug 12, 2015 at 08:11:29AM +0100, Pavel Fedin wrote:
>  Hello!

Hi Pavel,

> > I dropped the acks and tested-by because of that change, but I'll happily
> > add them back if Lorenzo and Pavel confirm.  
> 
>  Confirm.
>  Tested-by: Pavel Fedin <p.fedin@samsung.com>
> 
>  I also added MSI support. Can i post it as patch on top of your branch?

There shouldn't be any need with the changes queued in tip/irq/core. Can
you give the following branch a go, please (it doesn't look like Bjorn's
stuff is in linux-next, unfortunately)?

  git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git devel

It's a temporary testing branch (subject to rebasing), but it should be
indicative of what's queued for 4.3.

Will
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Lorenzo Pieralisi Aug. 12, 2015, 9:15 a.m. UTC | #4
On Wed, Aug 05, 2015 at 12:49:56AM +0100, Bjorn Helgaas wrote:
> On Wed, Aug 05, 2015 at 02:23:38AM +0530, Jayachandran C wrote:
> > The current code in pci-host-generic.c uses pci_common_init_dev()
> > from arm architecture to do some part of the PCI setup, and this
> > prevents it from being used with arm64 architecture.
> > 
> > The part of pci_common_init_dev() that is really needed by
> > pci-host-generic.c is very limited and can be done in the same
> > file without using hw_pci API of ARM. The ARM platform requires
> > a pci_sys_data as sysdata for the PCI bus, this can be handled by
> > setting up gen_pci to have a pci_sys_data variable as the first
> > element.
> > 
> > Signed-off-by: Jayachandran C <jchandra@broadcom.com>
> > Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
> > Tested-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
> > Tested-by: Pavel Fedin <p.fedin@samsung.com>
> 
> I applied all three of these to my pci/enumeration branch for v4.3.
> 
> I made a few changes, the most important being to call
> pcie_bus_configure_settings() before pci_bus_add_devices(), because drivers
> may claim devices in pci_bus_add_devices(), and the PCI core shouldn't
> touch devices after drivers claim them.
> 
> I dropped the acks and tested-by because of that change, but I'll happily
> add them back if Lorenzo and Pavel confirm.  The patches are here if you
> want to review/test them:
> 
> https://git.kernel.org/cgit/linux/kernel/git/helgaas/pci.git/log/?h=pci/enumeration
> 

I am happy with your changes so you can certainly add my acked-by/tested-by
tags back, with thanks.

Thank you !
Lorenzo

> I'm sure the other patches on that branch will need some tweaks, too, so I
> don't have any problem with updating these.
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Pavel Fedin Aug. 14, 2015, 1:44 p.m. UTC | #5
Hello!

> >  I also added MSI support. Can i post it as patch on top of your branch?
> 
> There shouldn't be any need with the changes queued in tip/irq/core. Can
> you give the following branch a go, please (it doesn't look like Bjorn's
> stuff is in linux-next, unfortunately)?
> 
>   git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git devel

 I have checked, they already implemented generic handling for "msi-parent" property in the device
tree, and MSI works out of the box.

Kind regards,
Pavel Fedin
Expert Engineer
Samsung Electronics Research center Russia


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Bjorn Helgaas Aug. 14, 2015, 2:46 p.m. UTC | #6
On Wed, Aug 12, 2015 at 10:04:50AM +0100, Will Deacon wrote:
> On Wed, Aug 12, 2015 at 08:11:29AM +0100, Pavel Fedin wrote:
> > > I dropped the acks and tested-by because of that change, but I'll happily
> > > add them back if Lorenzo and Pavel confirm.  
> > 
> >  Confirm.
> >  Tested-by: Pavel Fedin <p.fedin@samsung.com>
> > 
> >  I also added MSI support. Can i post it as patch on top of your branch?
> 
> There shouldn't be any need with the changes queued in tip/irq/core. Can
> you give the following branch a go, please (it doesn't look like Bjorn's
> stuff is in linux-next, unfortunately)?

We still have a build issue (undefined reference to pci_write_msi_msg
in imx_v6_v7_defconfig) to resolve before putting it in linux-next.
Hopefully we can resolve that today.
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Lorenzo Pieralisi Aug. 14, 2015, 3:24 p.m. UTC | #7
Hi Bjorn,

On Fri, Aug 14, 2015 at 03:46:44PM +0100, Bjorn Helgaas wrote:
> On Wed, Aug 12, 2015 at 10:04:50AM +0100, Will Deacon wrote:
> > On Wed, Aug 12, 2015 at 08:11:29AM +0100, Pavel Fedin wrote:
> > > > I dropped the acks and tested-by because of that change, but I'll happily
> > > > add them back if Lorenzo and Pavel confirm.  
> > > 
> > >  Confirm.
> > >  Tested-by: Pavel Fedin <p.fedin@samsung.com>
> > > 
> > >  I also added MSI support. Can i post it as patch on top of your branch?
> > 
> > There shouldn't be any need with the changes queued in tip/irq/core. Can
> > you give the following branch a go, please (it doesn't look like Bjorn's
> > stuff is in linux-next, unfortunately)?
> 
> We still have a build issue (undefined reference to pci_write_msi_msg
> in imx_v6_v7_defconfig) to resolve before putting it in linux-next.
> Hopefully we can resolve that today.

I have sent you a fix for that, please let me know if that's ok with
you or you want me to rework it.

Thanks,
Lorenzo
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diff mbox

Patch

diff --git a/drivers/pci/host/pci-host-generic.c b/drivers/pci/host/pci-host-generic.c
index ba46e58..53703e3 100644
--- a/drivers/pci/host/pci-host-generic.c
+++ b/drivers/pci/host/pci-host-generic.c
@@ -38,7 +38,15 @@  struct gen_pci_cfg_windows {
 	const struct gen_pci_cfg_bus_ops	*ops;
 };
 
+/*
+ * ARM needs platform specific pci_sys_data as the sysdata for PCI.
+ * We add the sys as the first field below to handle this. sys will
+ * set to 0, so that the pci functions in do the right thing.
+ */
 struct gen_pci {
+#ifdef CONFIG_ARM
+	struct pci_sys_data			sys;
+#endif
 	struct pci_host_bridge			host;
 	struct gen_pci_cfg_windows		cfg;
 	struct list_head			resources;
@@ -48,8 +56,7 @@  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 +71,7 @@  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);
@@ -198,13 +204,6 @@  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;
@@ -214,13 +213,7 @@  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,
-	};
+	struct pci_bus *bus;
 
 	if (!pci)
 		return -ENOMEM;
@@ -258,7 +251,31 @@  static int gen_pci_probe(struct platform_device *pdev)
 		return err;
 	}
 
-	pci_common_init_dev(dev, &hw);
+	/* do not reassign resource if probe only */
+	if (!pci_has_flag(PCI_PROBE_ONLY))
+		pci_add_flags(PCI_REASSIGN_ALL_RSRC | PCI_REASSIGN_ALL_BUS);
+
+	bus = pci_scan_root_bus(dev, 0, &gen_pci_ops, pci, &pci->resources);
+	if (!bus) {
+		dev_err(dev, "Scanning rootbus failed");
+		return -ENODEV;
+	}
+
+	pci_fixup_irqs(pci_common_swizzle, of_irq_parse_and_map_pci);
+
+	if (!pci_has_flag(PCI_PROBE_ONLY)) {
+		pci_bus_size_bridges(bus);
+		pci_bus_assign_resources(bus);
+	}
+	pci_bus_add_devices(bus);
+
+	/* Configure PCI Express settings */
+	if (!pci_has_flag(PCI_PROBE_ONLY)) {
+		struct pci_bus *child;
+
+		list_for_each_entry(child, &bus->children, node)
+			pcie_bus_configure_settings(child);
+	}
 	return 0;
 }