drivers: pci: remove unused pci_sys_data structures

Commit b3a72384fe29 ("ARM/PCI: Replace pci_sys_data->align_resource with global function pointer") removed the struct pci_sys_data dependency from the ARM pcibios functions that are part of the common ARM PCI arch back-end (eg pcibios_align_resource()), so that struct pci_sys_data has now become data that is only used internally by the ARM bios32 layer (ie pci_common_init_dev()) and by host controllers drivers callbacks (eg pci_sys_data.setup) that rely on the ARM bios32 API to probe.

PCI host controller drivers that do not rely on ARM bios32 calls to probe do not need to have the pci_bus.sysdata pointer field pointing at a struct pci_sys_data anymore, therefore it can be removed from the respective drivers data structures.

This patch removes the pci_sys_data structures from the host controller drivers that do not rely on ARM bios32 interface to scan the PCI bus, completing the pci_sys_data clean-up and removing the related dependency on arch/arm specific data.

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

Cc Arnd Bergmann <[email protected]>

Cc Will Deacon <[email protected]>

Cc Bjorn Helgaas <[email protected]>

Cc Rob Herring <[email protected]>

Nice!

Acked-by Arnd Bergmann <[email protected]>

On the downside, I just saw how b3a72384fe29 ("ARM/PCI: Replace pci_sys_data->align_resource with global function pointer") manages to get rid of the last user of this, and how this is not the way we had planned for it to be done.

It doesn't matter that much, because there is only a single user of hw->align_resource, but this is now unportable code and cannot easily be separated from hw_pci. It also breaks if we ever get a machine with two different host controllers on ARM that don't use the same pointer here.

I really would have hoped we could put that function pointer into 'struct pci_host_bridge' instead, and eventually killed off the architecture specific pcibios_align_resource function as well.

Any idea why it was done with a global function pointer for ARM rather than a proper solution?

Arnd

Quoted 13 lines

Acked-by Arnd Bergmann <[email protected]>

On the downside, I just saw how b3a72384fe29 ("ARM/PCI: Replace pci_sys_data->align_resource with global function pointer") manages to get rid of the last user of this, and how this is not the way we had planned for it to be done.

It doesn't matter that much, because there is only a single user of hw->align_resource, but this is now unportable code and cannot easily be separated from hw_pci. It also breaks if we ever get a machine with two different host controllers on ARM that don't use the same pointer here.

Quoted 4 lines

I really would have hoped we could put that function pointer into 'struct pci_host_bridge' instead, and eventually killed off the architecture specific pcibios_align_resource function as well.

say we move that in pci_host_bridge struct,

Are you suggesting to modify pcibios_init_hw to assign the align_resource function pointer at the end after pci_scan_root_bus_msi() has created the host bridge structure; then we can retrieve it in pcibios_align_resource using pci_find_host_bridge(dev->bus)....?

Quoted 2 lines

Any idea why it was done with a global function pointer for ARM rather than a proper solution?

Well just because I didn't think about the solution above...

If you think the above one can work I can send out another patch to fix this...

Commit b3a72384fe29 ("ARM/PCI: Replace pci_sys_data->align_resource with global function pointer") removed the struct pci_sys_data dependency from the ARM pcibios functions that are part of the common ARM PCI arch back-end (eg pcibios_align_resource()), so that struct pci_sys_data has now become data that is only used internally by the ARM bios32 layer (ie pci_common_init_dev()) and by host controllers drivers callbacks (eg pci_sys_data.setup) that rely on the ARM bios32 API to probe.

PCI host controller drivers that do not rely on ARM bios32 calls to probe do not need to have the pci_bus.sysdata pointer field pointing at a struct pci_sys_data anymore, therefore it can be removed from the respective drivers data structures.

This patch removes the pci_sys_data structures from the host controller drivers that do not rely on ARM bios32 interface to scan the PCI bus, completing the pci_sys_data clean-up and removing the related dependency on arch/arm specific data.

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

Cc Arnd Bergmann <[email protected]>

Cc Will Deacon <[email protected]>

Cc Bjorn Helgaas <[email protected]>

Cc Rob Herring <[email protected]>

---
Rob,

I could not test it on versatile, only compile tested, so please have an additional look.

Tested the PCI host generic on 32-bit and 64-bit guests, through kvmtool.

Thanks,
Lorenzo

 drivers/pci/host/pci-host-generic.c | 9 ---------
 drivers/pci/host/pci-versatile.c    | 5 +----
 2 files changed, 1 insertion(+), 13 deletions(-)

drivers/pci/host/pci-host-generic.c +0 -9

index 5434c90..1652bc7 100644
@@ -38,16 +38,7 @@ struct gen_pci_cfg_windows {
 	struct gen_pci_cfg_bus_ops		*ops;
 };
 
-/*
- * ARM pcibios functions expect the ARM struct pci_sys_data as the PCI
- * sysdata.  Add pci_sys_data as the first element in struct gen_pci so
- * that when we use a gen_pci pointer as sysdata, it is also a pointer to
- * a struct pci_sys_data.
- */
 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;

drivers/pci/host/pci-versatile.c +1 -4

index 0863d9c..f843a72 100644
@@ -125,9 +125,6 @@ out_release_res:
 	return err;
 }
 
-/* Unused, temporary to satisfy ARM arch code */
-struct pci_sys_data sys;
-
 static int versatile_pci_probe(struct platform_device *pdev)
 {
 	struct resource *res;

@@ -208,7 +205,7 @@ static int versatile_pci_probe(struct platform_device *pdev)
 	pci_add_flags(PCI_ENABLE_PROC_DOMAINS);
 	pci_add_flags(PCI_REASSIGN_ALL_BUS | PCI_REASSIGN_ALL_RSRC);
 
-	bus = pci_scan_root_bus(&pdev->dev, 0, &pci_versatile_ops, &sys, &pci_res);
+	bus = pci_scan_root_bus(&pdev->dev, 0, &pci_versatile_ops, NULL, &pci_res);
 	if (!bus)
 		return -ENOMEM;
 

Signature · 6 lines

2.5.1

--
To unsubscribe from this list: send the line "unsubscribe linux-pci" in
the body of a message to majordomo at vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html