diff mbox series

[1/2] PCI: Introduce PCI_FIXUP_IOMMU

Message ID 1590493749-13823-2-git-send-email-zhangfei.gao@linaro.org
State New
Headers show
Series Introduce PCI_FIXUP_IOMMU | expand

Commit Message

Zhangfei Gao May 26, 2020, 11:49 a.m. UTC
Some platform devices appear as PCI but are actually on the AMBA bus,
and they need fixup in drivers/pci/quirks.c handling iommu_fwnode.
Here introducing PCI_FIXUP_IOMMU, which is called after iommu_fwnode
is allocated, instead of reusing PCI_FIXUP_FINAL since it will slow
down iommu probing as all devices in fixup final list will be
reprocessed.

Suggested-by: Joerg Roedel <joro@8bytes.org>
Signed-off-by: Zhangfei Gao <zhangfei.gao@linaro.org>
---
 drivers/pci/quirks.c              | 7 +++++++
 include/asm-generic/vmlinux.lds.h | 3 +++
 include/linux/pci.h               | 8 ++++++++
 3 files changed, 18 insertions(+)

Comments

Christoph Hellwig May 26, 2020, 2:46 p.m. UTC | #1
On Tue, May 26, 2020 at 07:49:08PM +0800, Zhangfei Gao wrote:
> Some platform devices appear as PCI but are actually on the AMBA bus,
> and they need fixup in drivers/pci/quirks.c handling iommu_fwnode.
> Here introducing PCI_FIXUP_IOMMU, which is called after iommu_fwnode
> is allocated, instead of reusing PCI_FIXUP_FINAL since it will slow
> down iommu probing as all devices in fixup final list will be
> reprocessed.

Who is going to use this?  I don't see a single user in the series.
Zhangfei Gao May 26, 2020, 3:09 p.m. UTC | #2
Hi, Christoph

On 2020/5/26 下午10:46, Christoph Hellwig wrote:
> On Tue, May 26, 2020 at 07:49:08PM +0800, Zhangfei Gao wrote:
>> Some platform devices appear as PCI but are actually on the AMBA bus,
>> and they need fixup in drivers/pci/quirks.c handling iommu_fwnode.
>> Here introducing PCI_FIXUP_IOMMU, which is called after iommu_fwnode
>> is allocated, instead of reusing PCI_FIXUP_FINAL since it will slow
>> down iommu probing as all devices in fixup final list will be
>> reprocessed.
> Who is going to use this?  I don't see a single user in the series.
We will add iommu fixup in drivers/pci/quirks.c, handling

fwspec->can_stall, which is introduced in

https://www.spinics.net/lists/linux-pci/msg94559.html

Unfortunately, the patch does not catch v5.8, so we have to wait.
And we want to check whether this is a right method to solve this issue.

Thanks
Greg KH May 27, 2020, 9:01 a.m. UTC | #3
On Tue, May 26, 2020 at 11:09:57PM +0800, Zhangfei Gao wrote:
> Hi, Christoph
> 
> On 2020/5/26 下午10:46, Christoph Hellwig wrote:
> > On Tue, May 26, 2020 at 07:49:08PM +0800, Zhangfei Gao wrote:
> > > Some platform devices appear as PCI but are actually on the AMBA bus,
> > > and they need fixup in drivers/pci/quirks.c handling iommu_fwnode.
> > > Here introducing PCI_FIXUP_IOMMU, which is called after iommu_fwnode
> > > is allocated, instead of reusing PCI_FIXUP_FINAL since it will slow
> > > down iommu probing as all devices in fixup final list will be
> > > reprocessed.
> > Who is going to use this?  I don't see a single user in the series.
> We will add iommu fixup in drivers/pci/quirks.c, handling
> 
> fwspec->can_stall, which is introduced in
> 
> https://www.spinics.net/lists/linux-pci/msg94559.html
> 
> Unfortunately, the patch does not catch v5.8, so we have to wait.
> And we want to check whether this is a right method to solve this issue.

We can't take new apis without a real user, so please submit them all at
once.

thanks,

greg k-h
diff mbox series

Patch

diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index ca9ed57..b037034 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -83,6 +83,8 @@  extern struct pci_fixup __start_pci_fixups_header[];
 extern struct pci_fixup __end_pci_fixups_header[];
 extern struct pci_fixup __start_pci_fixups_final[];
 extern struct pci_fixup __end_pci_fixups_final[];
+extern struct pci_fixup __start_pci_fixups_iommu[];
+extern struct pci_fixup __end_pci_fixups_iommu[];
 extern struct pci_fixup __start_pci_fixups_enable[];
 extern struct pci_fixup __end_pci_fixups_enable[];
 extern struct pci_fixup __start_pci_fixups_resume[];
@@ -118,6 +120,11 @@  void pci_fixup_device(enum pci_fixup_pass pass, struct pci_dev *dev)
 		end = __end_pci_fixups_final;
 		break;
 
+	case pci_fixup_iommu:
+		start = __start_pci_fixups_iommu;
+		end = __end_pci_fixups_iommu;
+		break;
+
 	case pci_fixup_enable:
 		start = __start_pci_fixups_enable;
 		end = __end_pci_fixups_enable;
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index 71e387a..3da32d8 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -411,6 +411,9 @@ 
 		__start_pci_fixups_final = .;				\
 		KEEP(*(.pci_fixup_final))				\
 		__end_pci_fixups_final = .;				\
+		__start_pci_fixups_iommu = .;				\
+		KEEP(*(.pci_fixup_iommu))				\
+		__end_pci_fixups_iommu = .;				\
 		__start_pci_fixups_enable = .;				\
 		KEEP(*(.pci_fixup_enable))				\
 		__end_pci_fixups_enable = .;				\
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 83ce1cd..0d5fbf8 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1892,6 +1892,7 @@  enum pci_fixup_pass {
 	pci_fixup_early,	/* Before probing BARs */
 	pci_fixup_header,	/* After reading configuration header */
 	pci_fixup_final,	/* Final phase of device fixups */
+	pci_fixup_iommu,	/* After iommu_fwspec_init */
 	pci_fixup_enable,	/* pci_enable_device() time */
 	pci_fixup_resume,	/* pci_device_resume() */
 	pci_fixup_suspend,	/* pci_device_suspend() */
@@ -1934,6 +1935,10 @@  enum pci_fixup_pass {
 					 class_shift, hook)		\
 	DECLARE_PCI_FIXUP_SECTION(.pci_fixup_final,			\
 		hook, vendor, device, class, class_shift, hook)
+#define DECLARE_PCI_FIXUP_CLASS_IOMMU(vendor, device, class,		\
+					 class_shift, hook)		\
+	DECLARE_PCI_FIXUP_SECTION(.pci_fixup_iommu,			\
+		hook, vendor, device, class, class_shift, hook)
 #define DECLARE_PCI_FIXUP_CLASS_ENABLE(vendor, device, class,		\
 					 class_shift, hook)		\
 	DECLARE_PCI_FIXUP_SECTION(.pci_fixup_enable,			\
@@ -1964,6 +1969,9 @@  enum pci_fixup_pass {
 #define DECLARE_PCI_FIXUP_FINAL(vendor, device, hook)			\
 	DECLARE_PCI_FIXUP_SECTION(.pci_fixup_final,			\
 		hook, vendor, device, PCI_ANY_ID, 0, hook)
+#define DECLARE_PCI_FIXUP_IOMMU(vendor, device, hook)			\
+	DECLARE_PCI_FIXUP_SECTION(.pci_fixup_iommu,			\
+		hook, vendor, device, PCI_ANY_ID, 0, hook)
 #define DECLARE_PCI_FIXUP_ENABLE(vendor, device, hook)			\
 	DECLARE_PCI_FIXUP_SECTION(.pci_fixup_enable,			\
 		hook, vendor, device, PCI_ANY_ID, 0, hook)