Subject: Re: [02/12,v3] pci: fsl: add structure fsl_pci

From: Lian Minghuan-b31939 <[email-masked]>
Date: Mon, 6 Jan 2014 14:10:08 +0800

On 01/04/2014 06:19 AM, Scott Wood wrote:
> On Wed, Oct 23, 2013 at 06:41:24PM +0800, Minghuan Lian wrote:
>> PowerPC uses structure pci_controller to describe PCI controller,
>> but ARM uses structure pci_sys_data. In order to support PowerPC
>> and ARM simultaneously, the patch adds a structure fsl_pci that
>> contains most of the members of the pci_controller and pci_sys_data.
>> Meanwhile, it defines a interface fsl_arch_sys_to_pci() which should
>> be implemented in architecture-specific PCI controller driver to
>> convert pci_controller or pci_sys_data to fsl_pci.
>>
>> Signed-off-by: Minghuan Lian <[email-masked]>
>>
>> ---
>> change log:
>> v1-v3:
>> Derived from http://patchwork.ozlabs.org/patch/278965/
>>
>> Based on upstream master.
>> Based on the discussion of RFC version here
>> http://patchwork.ozlabs.org/patch/274487/
>>
>>   include/linux/fsl/pci-common.h | 41 +++++++++++++++++++++++++++++++++++++++++
>>   1 file changed, 41 insertions(+)
>>
>> diff --git a/include/linux/fsl/pci-common.h b/include/linux/fsl/pci-common.h
>> index 5e4f683..e56a040 100644
>> --- a/include/linux/fsl/pci-common.h
>> +++ b/include/linux/fsl/pci-common.h
>> @@ -102,5 +102,46 @@ struct ccsr_pci {
>>   
>>   };
>>   
>> +/*
>> + * Structure of a PCI controller (host bridge)
>> + */
>> +struct fsl_pci {
>> +	struct list_head node;
>> +	bool is_pcie;
>> +	struct device_node *dn;
>> +	struct device *dev;
>> +
>> +	int first_busno;
>> +	int last_busno;
>> +	int self_busno;
>> +	struct resource busn;
>> +
>> +	struct pci_ops *ops;
>> +	struct ccsr_pci __iomem *regs;
>> +
>> +	u32 indirect_type;
>> +
>> +	struct resource io_resource;
>> +	resource_size_t io_base_phys;
>> +	resource_size_t pci_io_size;
>> +
>> +	struct resource mem_resources[3];
>> +	resource_size_t mem_offset[3];
>> +
>> +	int global_number;	/* PCI domain number */
>> +
>> +	resource_size_t dma_window_base_cur;
>> +	resource_size_t dma_window_size;
>> +
>> +	void *sys;
>> +};
> I don't like the extent to which this duplicates (not moves) PPC's struct
> pci_controller.  Also this leaves some fields like "indirect_type"
> unexplained (PPC_INDIRECT_TYPE_xxx is only in the PPC header).
>
> Does the arch-independent part of the driver really need all this?  Given
> how closely this tracks the PPC code, how would this work on ARM?
[Minghuan] I added the duplicate fields because PPC's struct 
pci_controller need them.
The common PCI driver gets the related information and pass to PowerPC 
driver.
And I do hope PowerPC driver to parse dts or access controller to get 
the information again.
please see the following code for PowerPC:
int fsl_arch_pci_sys_register(struct fsl_pci *pci)
+{
+    struct pci_controller *hose;

+    hose = pcibios_alloc_controller(pci->dn);
+
+    hose->private_data = pci;
+    hose->parent = pci->dev;
+    hose->first_busno = pci->first_busno;
+    hose->last_busno = pci->last_busno;
+    hose->ops = pci->ops;
+
+    hose->io_base_virt = ioremap(pci->io_base_phys + 
pci->io_resource.start,
+                     pci->pci_io_size);
+    hose->pci_io_size = pci->io_resource.start + pci->pci_io_size;
+    hose->io_base_phys = pci->io_base_phys;
+    hose->io_resource = pci->io_resource;
+
+    memcpy(hose->mem_offset, pci->mem_offset, sizeof(hose->mem_offset));
+    memcpy(hose->mem_resources, pci->mem_resources,
+        sizeof(hose->mem_resources));
+    hose->dma_window_base_cur = pci->dma_window_base_cur;
+    hose->dma_window_size = pci->dma_window_size;
+    pci->sys = hose;
+....
+    return 0;
+}

The following is for ARM, I will submit them after verification:

+
+static inline struct fsl_pcie *sys_to_pcie(struct pci_sys_data *sys)
+{
+    return sys->private_data;
+}
+
+static int fsl_pcie_setup(int nr, struct pci_sys_data *sys)
+{
+    struct fsl_pcie *pcie;
+
+    pcie = sys_to_pcie(sys);
+
+    if (!pcie)
+        return 0;
+
+    pcie->sys = sys;
+
+    sys->io_offset = pcie->io_base_phys;
+    pci_ioremap_io(sys->io_offset, pcie->io_resource.start);
+    pci_add_resource_offset(&sys->resources, &pcie->io_resource,
+                sys->io_offset);
+
+    sys->mem_offset = pcie->mem_offset;
+    pci_add_resource_offset(&sys->resources, &pcie->mem_resource,
+                sys->mem_offset);
+
+    return 1;
+}
+
+static struct pci_bus *
+fsl_pcie_scan_bus(int nr, struct pci_sys_data *sys)
+{
+    struct pci_bus *bus;
+    struct fsl_pcie *pcie = sys_to_pcie(sys);
+
+    bus = pci_create_root_bus(pcie->dev, sys->busnr,
+                  pcie->ops, sys, &sys->resources);
+    if (!bus)
+        return NULL;
+
+    pci_scan_child_bus(bus);
+
+    return bus;
+}
+
+static int fsl_pcie_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
+{
+    struct of_irq oirq;
+    int ret;
+
+    ret = of_irq_map_pci(dev, &oirq);
+    if (ret)
+        return ret;
+
+    return irq_create_of_mapping(oirq.controller, oirq.specifier,
+                     oirq.size);
+}
+
+static struct hw_pci fsl_hw_pcie = {
+    .ops        = &fsl_indirect_pci_ops;
+    .setup        = fsl_pcie_setup,
+    .scan        = fsl_pcie_scan_bus,
+    .map_irq    = fsl_pcie_map_irq,
+};

+static struct pci_bus *
+fake_pci_bus(struct fsl_pcie *pcie, int busnr)
+{
+    static struct pci_bus bus;
+    static struct pci_sys_data sys;
+
+    bus.number = busnr;
+    bus.sysdata = &sys;
+    sys.private_data = pcie;
+    bus.ops = pcie->ops;
+    return &bus;
+}
+
+static int fsl_pcie_register(struct fsl_pcie *pcie)
+{
+    pcie->controller = fsl_hw_pcie.nr_controllers;
+    fsl_hw_pcie.nr_controllers = 1;
+    fsl_hw_pcie.private_data = (void **)&pcie;
+
+    pci_common_init(&fsl_hw_pcie);
+    pci_assign_unassigned_resources();
+#ifdef CONFIG_PCI_DOMAINS
+    fsl_hw_pcie.domain++;
+#endif
+}

> -Scott