[PATCH kernel v2 6/6] powerpc/pci: Remove OF node back pointer from pci_dn

[Alexey Kardashevskiy]

The check_req() helper uses pci_get_pdn() to get an OF node pointer.
pci_get_pdn() returns a pci_dn pointer which either:
1) from the OF node returned by pci_device_to_OF_node();
2) from the parent child_list where entries don't have OF node pointers.
Since check_req() does not care about 2), it can call
pci_device_to_OF_node() directly, hence the change.

The find_pe_dn() helper uses embedded pci_dn to get an OF node which is
also stored in edev->pdev so let's take a shortcut and call
pci_device_to_OF_node() directly.

With these 2 changes, we can finally get rid of the OF node back pointer.

Signed-off-by: Alexey Kardashevskiy <a...@ozlabs.ru>
---
Changelog:
v2:
* fixed pseries platform
---
 arch/powerpc/include/asm/pci-bridge.h |  1 -
 arch/powerpc/kernel/pci_dn.c          |  1 -
 arch/powerpc/platforms/pseries/msi.c  | 11 ++---------
 3 files changed, 2 insertions(+), 11 deletions(-)

diff --git a/arch/powerpc/include/asm/pci-bridge.h 
b/arch/powerpc/include/asm/pci-bridge.h
index 56c67d3f0108..0b8aa1fe2d5f 100644
--- a/arch/powerpc/include/asm/pci-bridge.h
+++ b/arch/powerpc/include/asm/pci-bridge.h
@@ -195,7 +195,6 @@ struct pci_dn {
        struct  pci_dn *parent;
        struct  pci_controller *phb;    /* for pci devices */
        struct  iommu_table_group *table_group; /* for phb's or bridges */
-       struct  device_node *node;      /* back-pointer to the device_node */
 
        int     pci_ext_config_space;   /* for pci devices */
 
diff --git a/arch/powerpc/kernel/pci_dn.c b/arch/powerpc/kernel/pci_dn.c
index dfb107631116..0e395afbf0f4 100644
--- a/arch/powerpc/kernel/pci_dn.c
+++ b/arch/powerpc/kernel/pci_dn.c
@@ -293,7 +293,6 @@ struct pci_dn *pci_add_device_node_info(struct 
pci_controller *hose,
        if (pdn == NULL)
                return NULL;
        dn->data = pdn;
-       pdn->node = dn;
        pdn->phb = hose;
 #ifdef CONFIG_PPC_POWERNV
        pdn->pe_number = IODA_INVALID_PE;
diff --git a/arch/powerpc/platforms/pseries/msi.c 
b/arch/powerpc/platforms/pseries/msi.c
index 326ef0dd6038..70b7aeff8139 100644
--- a/arch/powerpc/platforms/pseries/msi.c
+++ b/arch/powerpc/platforms/pseries/msi.c
@@ -132,15 +132,10 @@ static void rtas_teardown_msi_irqs(struct pci_dev *pdev)
 static int check_req(struct pci_dev *pdev, int nvec, char *prop_name)
 {
        struct device_node *dn;
-       struct pci_dn *pdn;
        const __be32 *p;
        u32 req_msi;
 
-       pdn = pci_get_pdn(pdev);
-       if (!pdn)
-               return -ENODEV;
-
-       dn = pdn->node;
+       dn = pci_device_to_OF_node(pdev);
 
        p = of_get_property(dn, prop_name, NULL);
        if (!p) {
@@ -197,7 +192,6 @@ static struct device_node *find_pe_total_msi(struct pci_dev 
*dev, int *total)
 static struct device_node *find_pe_dn(struct pci_dev *dev, int *total)
 {
        struct device_node *dn;
-       struct pci_dn *pdn;
        struct eeh_dev *edev;
 
        /* Found our PE and assume 8 at that point. */
@@ -210,8 +204,7 @@ static struct device_node *find_pe_dn(struct pci_dev *dev, 
int *total)
        edev = pdn_to_eeh_dev(PCI_DN(dn));
        if (edev->pe)
                edev = list_first_entry(&edev->pe->edevs, struct eeh_dev, list);
-       pdn = eeh_dev_to_pdn(edev);
-       dn = pdn ? pdn->node : NULL;
+       dn = pci_device_to_OF_node(edev->pdev);
        if (!dn)
                return NULL;
 
-- 
2.11.0