Subject: [PATCH V3 19/21] pci, acpi: Support for ACPI based generic PCI host controller init

From: [email-masked] (liudongdong (C))
Date: Mon, 18 Jan 2016 17:25:18 +0800

Hi Tomasz,

? 2016/1/13 21:21, Tomasz Nowicki ??:
> Because of two patch series:
> 1. Jiang Liu's common interface to support PCI host controller init
> 2. MMCONFIG refactoring (part of this patch set)
> now we can think about generic ACPI based PCI host controller init
> implementation out of arch/ directory.
>
> These calls use information from MCFG table (PCI config space regions)
> and _CRS method (IO/irq resources) to initialize PCI hostbridge.
>
> TBD: We are still not sure whether we should reassign resources
> after PCI bus enumeration or trust firmware to do all that work for
> us properly.
>
> Signed-off-by: Tomasz Nowicki <[email-masked]>
> Signed-off-by: Hanjun Guo <[email-masked]>
> Signed-off-by: Suravee Suthikulpanit <[email-masked]>
> CC: Arnd Bergmann <[email-masked]>
> CC: Catalin Marinas <[email-masked]>
> CC: Liviu Dudau <[email-masked]>
> CC: Lorenzo Pieralisi <[email-masked]>
> CC: Will Deacon <[email-masked]>
> Tested-by: Suravee Suthikulpanit <[email-masked]>
> Tested-by: Jeremy Linton <[email-masked]>
> ---
>   drivers/acpi/Kconfig    |   5 ++
>   drivers/acpi/pci_root.c | 131 ++++++++++++++++++++++++++++++++++++++++++++++++
>   2 files changed, 136 insertions(+)
>
> diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
> index c3664be..e315061 100644
> --- a/drivers/acpi/Kconfig
> +++ b/drivers/acpi/Kconfig
> @@ -335,6 +335,11 @@ config ACPI_PCI_SLOT
>   	  i.e., segment/bus/device/function tuples, with physical slots in
>   	  the system.  If you are unsure, say N.
>
> +config ACPI_PCI_HOST_GENERIC
> +	bool "Generic ACPI PCI host controller"
> +	help
> +	  Say Y here if you want to support generic ACPI PCI host controller.
> +
>   config X86_PM_TIMER
>   	bool "Power Management Timer Support" if EXPERT
>   	depends on X86
> diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
> index a65c8c2..d483e2a 100644
> --- a/drivers/acpi/pci_root.c
> +++ b/drivers/acpi/pci_root.c
> @@ -24,6 +24,7 @@
>   #include <linux/init.h>
>   #include <linux/types.h>
>   #include <linux/mutex.h>
> +#include <linux/of_address.h>
>   #include <linux/pm.h>
>   #include <linux/pm_runtime.h>
>   #include <linux/pci.h>
> @@ -514,6 +515,136 @@ static void negotiate_os_control(struct acpi_pci_root *root, int *no_aspm)
>   	}
>   }
>
> +#ifdef CONFIG_ACPI_PCI_HOST_GENERIC
> +static int pcibios_map_irq(struct pci_dev *dev, u8 slot, u8 pin)
> +{
> +	if (pci_dev_msi_enabled(dev))
> +		return 0;
> +
> +	acpi_pci_irq_enable(dev);
> +	return dev->irq;
> +}
> +
> +static void pci_mcfg_release_info(struct acpi_pci_root_info *ci)
> +{
> +	pci_mmcfg_teardown_map(ci);
> +	kfree(ci);
> +}
> +
> +static int pci_acpi_root_prepare_resources(struct acpi_pci_root_info *ci)
> +{
> +	struct list_head *list = &ci->resources;
> +	struct acpi_device *device = ci->bridge;
> +	struct resource_entry *entry, *tmp;
> +	unsigned long flags;
> +	int ret;
> +
> +	flags = IORESOURCE_IO | IORESOURCE_MEM;
> +	ret = acpi_dev_get_resources(device, list,
> +				     acpi_dev_filter_resource_type_cb,
> +				     (void *)flags);
> +	if (ret < 0) {
> +		dev_warn(&device->dev,
> +			 "failed to parse _CRS method, error code %d\n", ret);
> +		return ret;
> +	} else if (ret == 0)
> +		dev_dbg(&device->dev,
> +			"no IO and memory resources present in _CRS\n");
> +
> +	resource_list_for_each_entry_safe(entry, tmp, &ci->resources) {
> +		resource_size_t cpu_addr, length;
> +		struct resource *res = entry->res;
> +
> +		if (entry->res->flags & IORESOURCE_DISABLED)
> +			resource_list_destroy_entry(entry);
> +		else
> +			res->name = ci->name;
> +
> +		/* PCI -> CPU space translation */
> +		cpu_addr = res->start + entry->offset;
> +		length = res->end - res->start + 1;

I see here is different from V2 patch,
in V2 patch,  0x0000022004000000 is cpu addr.
but in V3 patch, 0x0000022004000000 is pci addr.
which one is right ?

0x0000022004000000  is the value of AddressMinimum.
AddressMinimum evaluates to a 64-bit integer that specifies the lowest possible base address of the Memory range
QWordMemory ( // 64-bit BAR Windows
	ResourceProducer, PosDecode,
	MinFixed, MaxFixed,
	Cacheable, ReadWrite,
	0x000000000000000, // Granularity
	0x0000022004000000, // Min Base Address
	0x000002200fffffff, // Max Base Address
	0x0000021ff9000000, // Translate
	0x000000000c000000 // Length
)

Thanks
Dongdong
> +
> +		if (res->flags & IORESOURCE_MEM) {
> +			res->start = cpu_addr;
> +			res->end = cpu_addr + length - 1;
> +		} else if (res->flags & IORESOURCE_IO) {
> +			resource_size_t pci_addr = res->start;
> +			unsigned long port;
> +
> +			if (pci_register_io_range(cpu_addr, length)) {
> +				resource_list_destroy_entry(entry);
> +				continue;
> +			}
> +
> +			port = pci_address_to_pio(cpu_addr);
> +			if (port == (unsigned long)-1) {
> +				resource_list_destroy_entry(entry);
> +				continue;
> +			}
> +
> +			res->start = port;
> +			res->end = port + length - 1;
> +			entry->offset = port - pci_addr;
> +
> +			if (pci_remap_iospace(res, cpu_addr) < 0)
> +				resource_list_destroy_entry(entry);
> +		}
> +	}
> +	return ret;
> +}
> +
> +static struct acpi_pci_root_ops acpi_pci_root_ops = {
> +	.init_info = pci_mmcfg_setup_map,
> +	.release_info = pci_mcfg_release_info,
> +	.prepare_resources = pci_acpi_root_prepare_resources,
> +};
> +
> +/* Root bridge scanning */
> +struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
> +{
> +	int node = acpi_get_node(root->device->handle);
> +	int domain = root->segment;
> +	int busnum = root->secondary.start;
> +	struct acpi_pci_root_info *info;
> +	struct pci_host_bridge *bridge;
> +	struct pci_bus *bus, *child;
> +
> +	if (domain && !pci_domains_supported) {
> +		pr_warn("PCI %04x:%02x: multiple domains not supported.\n",
> +			domain, busnum);
> +		return NULL;
> +	}
> +
> +	info = kzalloc_node(sizeof(*info), GFP_KERNEL, node);
> +	if (!info) {
> +		dev_err(&root->device->dev,
> +			"pci_bus %04x:%02x: ignored (out of memory)\n",
> +			domain, busnum);
> +		return NULL;
> +	}
> +
> +	acpi_pci_root_ops.pci_ops = pci_mcfg_get_ops(root);
> +	bus = acpi_pci_root_create(root, &acpi_pci_root_ops, info, root);
> +	if (!bus)
> +		return NULL;
> +
> +	bridge = pci_find_host_bridge(bus);
> +	bridge->map_irq = pcibios_map_irq;
> +
> +	pci_bus_size_bridges(bus);
> +	pci_bus_assign_resources(bus);
> +
> +	/*
> +	 * After the PCI-E bus has been walked and all devices discovered,
> +	 * configure any settings of the fabric that might be necessary.
> +	 */
> +	list_for_each_entry(child, &bus->children, node)
> +		pcie_bus_configure_settings(child);
> +
> +	return bus;
> +}
> +#endif /* CONFIG_ARCH_PCI_HOST_GENERIC_ACPI */
> +
>   static int acpi_pci_root_add(struct acpi_device *device,
>   			     const struct acpi_device_id *not_used)
>   {
>