Re: [PATCH v4 1/4] PCI: iproc: enable arm64 support for iProc PCIe

[Bjorn Helgaas <bhelgaas@google.com>]

On Tue, Jul 21, 2015 at 06:29:40PM -0700, Ray Jui wrote:
> This patch enables arm64 support to the iProc PCIe driver
> 
> Note struct pci_sys_data is arm32 specific and will eventually be
> removed. This change is done in such a way that when struct pci_sys_data
> is removed from arm32, one only needs to also remove it from
> pcie-iproc.h, no other change in the iProc PCIe core driver is needed
> 
> In addition, arm64 based PCI driver does not require call to
> pci_fixup_irqs, as it implements OF based irq parsing and mapping in
> pcibios_add_device
> 
> Signed-off-by: Ray Jui <rjui@broadcom.com>
> Reviewed-by: Scott Branden <sbranden@broadcom.com>
> ---
>  drivers/pci/host/pcie-iproc.c |   15 ++++-----------
>  drivers/pci/host/pcie-iproc.h |    8 ++++++--
>  2 files changed, 10 insertions(+), 13 deletions(-)
> 
> diff --git a/drivers/pci/host/pcie-iproc.c b/drivers/pci/host/pcie-iproc.c
> index d77481e..8a556d5 100644
> --- a/drivers/pci/host/pcie-iproc.c
> +++ b/drivers/pci/host/pcie-iproc.c
> @@ -58,11 +58,6 @@
>  #define SYS_RC_INTX_EN               0x330
>  #define SYS_RC_INTX_MASK             0xf
>  
> -static inline struct iproc_pcie *sys_to_pcie(struct pci_sys_data *sys)
> -{
> -	return sys->private_data;
> -}
> -
>  /**
>   * Note access to the configuration registers are protected at the higher layer
>   * by 'pci_lock' in drivers/pci/access.c
> @@ -71,8 +66,7 @@ static void __iomem *iproc_pcie_map_cfg_bus(struct pci_bus *bus,
>  					    unsigned int devfn,
>  					    int where)
>  {
> -	struct pci_sys_data *sys = bus->sysdata;
> -	struct iproc_pcie *pcie = sys_to_pcie(sys);
> +	struct iproc_pcie *pcie = bus->sysdata;

I'm thinking something like the following so we don't depend on
pci_sys_data being at the beginning of iproc_pcie.  What do you think?
It has more ifdefs but feels a bit safer.  And I don't mind if ugly code
comes with ugly ifdefs -- it's a little incentive to make the code cleaner.


commit 8d9bfe3702aaea457b3d59b09b86e9f03c322605
Author: Ray Jui <rjui@broadcom.com>
Date:   Tue Jul 21 18:29:40 2015 -0700

    PCI: iproc: Add arm64 support
    
    Add arm64 support to the iProc PCIe driver.
    
    Note that on arm32, bus->sysdata points to the arm32-specific pci_sys_data
    struct, and pci_sys_data.private_data contains the iproc_pcie pointer.
    For arm64, there's nothing corresponding to pci_sys_data, so we keep the
    iproc_pcie pointer directly in bus->sysdata.
    
    In addition, arm64 does IRQ mapping in pcibios_add_device(), so it doesn't
    need pci_fixup_irqs() as arm32 does.
    
    Signed-off-by: Ray Jui <rjui@broadcom.com>
    Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
    Reviewed-by: Scott Branden <sbranden@broadcom.com>

diff --git a/drivers/pci/host/pcie-iproc.c b/drivers/pci/host/pcie-iproc.c
index 9a00dca..fe2efb1 100644
--- a/drivers/pci/host/pcie-iproc.c
+++ b/drivers/pci/host/pcie-iproc.c
@@ -58,9 +58,17 @@
 #define SYS_RC_INTX_EN               0x330
 #define SYS_RC_INTX_MASK             0xf
 
-static inline struct iproc_pcie *sys_to_pcie(struct pci_sys_data *sys)
+static inline struct iproc_pcie *iproc_data(struct pci_bus *bus)
 {
-	return sys->private_data;
+	struct iproc_pcie *pcie;
+#ifdef CONFIG_ARM
+	struct pci_sys_data *sys = bus->sysdata;
+
+	pcie = sys->private_data;
+#else
+	pcie = bus->sysdata;
+#endif
+	return pcie;
 }
 
 /**
@@ -71,8 +79,7 @@ static void __iomem *iproc_pcie_map_cfg_bus(struct pci_bus *bus,
 					    unsigned int devfn,
 					    int where)
 {
-	struct pci_sys_data *sys = bus->sysdata;
-	struct iproc_pcie *pcie = sys_to_pcie(sys);
+	struct iproc_pcie *pcie = iproc_data(bus);
 	unsigned slot = PCI_SLOT(devfn);
 	unsigned fn = PCI_FUNC(devfn);
 	unsigned busno = bus->number;
@@ -186,6 +193,7 @@ static void iproc_pcie_enable(struct iproc_pcie *pcie)
 int iproc_pcie_setup(struct iproc_pcie *pcie, struct list_head *res)
 {
 	int ret;
+	void *sysdata;
 	struct pci_bus *bus;
 
 	if (!pcie || !pcie->dev || !pcie->base)
@@ -205,10 +213,14 @@ int iproc_pcie_setup(struct iproc_pcie *pcie, struct list_head *res)
 
 	iproc_pcie_reset(pcie);
 
+#ifdef CONFIG_ARM
 	pcie->sysdata.private_data = pcie;
+	sysdata = &pcie->sysdata;
+#else
+	sysdata = pcie;
+#endif
 
-	bus = pci_create_root_bus(pcie->dev, 0, &iproc_pcie_ops,
-				  &pcie->sysdata, res);
+	bus = pci_create_root_bus(pcie->dev, 0, &iproc_pcie_ops, sysdata, res);
 	if (!bus) {
 		dev_err(pcie->dev, "unable to create PCI root bus\n");
 		ret = -ENOMEM;
@@ -226,7 +238,9 @@ int iproc_pcie_setup(struct iproc_pcie *pcie, struct list_head *res)
 
 	pci_scan_child_bus(bus);
 	pci_assign_unassigned_bus_resources(bus);
+#ifdef CONFIG_ARM
 	pci_fixup_irqs(pci_common_swizzle, pcie->map_irq);
+#endif
 	pci_bus_add_devices(bus);
 
 	return 0;
diff --git a/drivers/pci/host/pcie-iproc.h b/drivers/pci/host/pcie-iproc.h
index ba0a108..c9e4c10 100644
--- a/drivers/pci/host/pcie-iproc.h
+++ b/drivers/pci/host/pcie-iproc.h
@@ -21,7 +21,7 @@
  * @dev: pointer to device data structure
  * @base: PCIe host controller I/O register base
  * @resources: linked list of all PCI resources
- * @sysdata: Per PCI controller data
+ * @sysdata: Per PCI controller data (ARM-specific)
  * @root_bus: pointer to root bus
  * @phy: optional PHY device that controls the Serdes
  * @irqs: interrupt IDs
@@ -29,7 +29,9 @@
 struct iproc_pcie {
 	struct device *dev;
 	void __iomem *base;
+#ifdef CONFIG_ARM
 	struct pci_sys_data sysdata;
+#endif
 	struct pci_bus *root_bus;
 	struct phy *phy;
 	int irqs[IPROC_PCIE_MAX_NUM_IRQS];