On Tue, Aug 03, 2021 at 06:14:51PM +0100, Lorenzo Pieralisi wrote:

On Tue, Jul 27, 2021 at 02:06:57AM +0800, Boqun Feng wrote:

quoted

Now we have everything we need, just provide a proper sysdata type for
the bus to use on ARM64 and everything else works.

Signed-off-by: Boqun Feng <redacted>
---
 drivers/pci/controller/pci-hyperv.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci-hyperv.c
index e6276aaa4659..62dbe98d1fe1 100644
--- a/drivers/pci/controller/pci-hyperv.c
+++ b/drivers/pci/controller/pci-hyperv.c

@@ -40,6 +40,7 @@
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/pci.h>
+#include <linux/pci-ecam.h>
 #include <linux/delay.h>
 #include <linux/semaphore.h>
 #include <linux/irqdomain.h>

@@ -448,7 +449,11 @@ enum hv_pcibus_state {
 };
 
 struct hv_pcibus_device {
+#ifdef CONFIG_X86
 	struct pci_sysdata sysdata;
+#elif defined(CONFIG_ARM64)
+	struct pci_config_window sysdata;

This is ugly. HV does not need pci_config_window at all right
(other than arm64 pcibios_root_bridge_prepare()) ?

Right.

The issue is that in HV you have to have *some* sysdata != NULL, it is
just some data to retrieve the hv_pcibus_device.

Mmaybe we can rework ARM64 ACPI code to store the acpi_device in struct
pci_host_bridge->private instead of retrieving it from pci_config_window
so that we decouple HV from the ARM64 back-end.

HV would just set struct pci_host_bridge->private == NULL.

Works for me, but please note that pci_sysdata is an x86-specific
structure, so we still need to define a fake pci_sysdata inside
pci-hyperv.c, like:

	#ifndef CONFIG_X86
	struct pci_sysdata { };
	#end

I need to think about this a bit, I don't think it should block
this series though but it would be nicer.

After a quick look into the code, seems that what we need to do is to
add an additional parameter for acpi_pci_root_create() and introduce a
slightly different version of pci_create_root_bus(). A question is:
should we only do this for ARM64, or should we also do this for
other acpi_pci_root_create() users (x86 and ia64)? Another question
comes to my mind is, while we are at it, is there anything else that we
want to move from sysdata to ->private? These questions are out of scope
of this patchset, I think. Maybe it's better that we address them in the
future, and I can send out separate RFC patches to start the discussion.
Does that sound like a plan to you?

Regards,
Boqun

Lorenzo

quoted

+#endif
 	struct pci_host_bridge *bridge;
 	struct fwnode_handle *fwnode;
 	/* Protocol version negotiated with the host */

@@ -3075,7 +3080,9 @@ static int hv_pci_probe(struct hv_device *hdev,
 			 dom_req, dom);
 
 	hbus->bridge->domain_nr = dom;
+#ifdef CONFIG_X86
 	hbus->sysdata.domain = dom;
+#endif
 
 	hbus->hdev = hdev;
 	INIT_LIST_HEAD(&hbus->children);

-- 
2.32.0

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