Re: [RFC PATCH V3 08/17] PCI: Add weak pcibios_sriov_resource_size() interface

[Wei Yang <weiyang@linux.vnet.ibm.com>]

On Mon, Jun 23, 2014 at 03:41:28PM +1000, Gavin Shan wrote:
>On Tue, Jun 10, 2014 at 09:56:30AM +0800, Wei Yang wrote:
>>When retrieving sriov resource size in pci_sriov_resource_size(), it will
>>divide the total IOV resource size with the totalVF number. This is true for
>>most cases, while may not be correct on some specific platform.
>>
>>For example on powernv platform, in order to fix the IOV BAR into a hardware
>>alignment, the IOV resource size would be expended. This means the original
>>method couldn't work.
>>
>>This patch introduces a weak pcibios_sriov_resource_size() interface, which
>>gives platform a chance to implement specific method to calculate the sriov
>>resource size.
>>
>>Signed-off-by: Wei Yang <weiyang@linux.vnet.ibm.com>
>>---
>> drivers/pci/iov.c   |   27 +++++++++++++++++++++++++--
>> include/linux/pci.h |    3 +++
>> 2 files changed, 28 insertions(+), 2 deletions(-)
>>
>>diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
>>index cc87773..9fd4648 100644
>>--- a/drivers/pci/iov.c
>>+++ b/drivers/pci/iov.c
>>@@ -45,6 +45,30 @@ static void virtfn_remove_bus(struct pci_bus *physbus, struct pci_bus *virtbus)
>> 		pci_remove_bus(virtbus);
>> }
>>
>>+resource_size_t __weak pcibios_sriov_resource_size(struct pci_dev *dev, int resno)
>>+{
>>+	return 0;
>>+}
>>+
>
>Please define the prototype of weak function in header files (e.g.
>linux/include/pci.h) :-)

Missed, will add it.

>
>If you missed doing same thing for the weak functions added in the
>previous patches, you need fix it as well.

Yep.

>
>>+resource_size_t pci_sriov_resource_size(struct pci_dev *dev, int resno)
>>+{
>>+	u64 size;
>
>I guess it'd better to be "resource_size_t". 
>
>>+	struct pci_sriov *iov;
>>+
>>+	if (!dev->is_physfn)
>>+		return 0;
>>+
>>+	size = pcibios_sriov_resource_size(dev, resno);
>>+	if (size != 0)
>>+		return size;
>>+
>>+	iov = dev->sriov;
>>+	size = resource_size(dev->resource + resno);
>>+	do_div(size, iov->total_VFs);
>>+
>>+	return size;
>>+}
>>+
>> static int virtfn_add(struct pci_dev *dev, int id, int reset)
>> {
>> 	int i;
>>@@ -81,8 +105,7 @@ static int virtfn_add(struct pci_dev *dev, int id, int reset)
>> 			continue;
>> 		virtfn->resource[i].name = pci_name(virtfn);
>> 		virtfn->resource[i].flags = res->flags;
>>-		size = resource_size(res);
>>-		do_div(size, iov->total_VFs);
>>+		size = pci_sriov_resource_size(dev, i + PCI_IOV_RESOURCES);
>> 		virtfn->resource[i].start = res->start + size * id;
>> 		virtfn->resource[i].end = virtfn->resource[i].start + size - 1;
>> 		rc = request_resource(res, &virtfn->resource[i]);
>>diff --git a/include/linux/pci.h b/include/linux/pci.h
>>index ddb1ca0..315c150 100644
>>--- a/include/linux/pci.h
>>+++ b/include/linux/pci.h
>>@@ -1637,6 +1637,7 @@ int pci_num_vf(struct pci_dev *dev);
>> int pci_vfs_assigned(struct pci_dev *dev);
>> int pci_sriov_set_totalvfs(struct pci_dev *dev, u16 numvfs);
>> int pci_sriov_get_totalvfs(struct pci_dev *dev);
>>+resource_size_t pci_sriov_resource_size(struct pci_dev *dev, int resno);
>> #else
>> static inline int pci_iov_virtfn_bus(struct pci_dev *dev, int id)
>> {
>>@@ -1658,6 +1659,8 @@ static inline int pci_sriov_set_totalvfs(struct pci_dev *dev, u16 numvfs)
>> { return 0; }
>> static inline int pci_sriov_get_totalvfs(struct pci_dev *dev)
>> { return 0; }
>>+static inline resource_size_t pci_sriov_resource_size(struct pci_dev *dev, int resno)
>>+{ return -1; }
>> #endif
>>
>> #if defined(CONFIG_HOTPLUG_PCI) || defined(CONFIG_HOTPLUG_PCI_MODULE)
>
>Thanks,
>Gavin

-- 
Richard Yang
Help you, Help me