Re: [Patch v2 19/22] x86/PCI/ACPI: Use common ACPI resource interfaces to simplify implementation

[Bjorn Helgaas <bhelgaas@google.com>]

On Wed, Jan 28, 2015 at 06:57:37PM +0800, Jiang Liu wrote:
> Use common ACPI resource discovery interfaces to simplify PCI host bridge
> resource enumeration.
> 
> It also fixes the issue discovered by Thomas that function setup_resource()
> incorrectly validates IO port resources against iomem_resource.

Is it possible to split this bug fix into its own separate patch?  Mixing
things together makes git archaeology harder because it hides tiny bug
fixes inside big changes.

> Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
> ---
>  arch/x86/pci/acpi.c |  296 ++++++++++++++++-----------------------------------
>  1 file changed, 94 insertions(+), 202 deletions(-)
> 
> diff --git a/arch/x86/pci/acpi.c b/arch/x86/pci/acpi.c
> index bb98afd0591e..3404ea703ecc 100644
> --- a/arch/x86/pci/acpi.c
> +++ b/arch/x86/pci/acpi.c
> @@ -10,9 +10,6 @@
>  struct pci_root_info {
>  	struct acpi_device *bridge;
>  	char name[16];
> -	unsigned int res_num;
> -	struct resource *res;
> -	resource_size_t *res_offset;
>  	struct pci_sysdata sd;
>  #ifdef	CONFIG_PCI_MMCONFIG
>  	bool mcfg_added;
> @@ -218,130 +215,44 @@ static void teardown_mcfg_map(struct pci_root_info *info)
>  }
>  #endif
>  
> -static acpi_status resource_to_addr(struct acpi_resource *resource,
> -				    struct acpi_resource_address64 *addr)
> -{
> -	acpi_status status;
> -	struct acpi_resource_memory24 *memory24;
> -	struct acpi_resource_memory32 *memory32;
> -	struct acpi_resource_fixed_memory32 *fixed_memory32;
> -
> -	memset(addr, 0, sizeof(*addr));
> -	switch (resource->type) {
> -	case ACPI_RESOURCE_TYPE_MEMORY24:
> -		memory24 = &resource->data.memory24;
> -		addr->resource_type = ACPI_MEMORY_RANGE;
> -		addr->address.minimum = memory24->minimum;
> -		addr->address.address_length = memory24->address_length;
> -		addr->address.maximum = addr->address.minimum + addr->address.address_length - 1;
> -		return AE_OK;
> -	case ACPI_RESOURCE_TYPE_MEMORY32:
> -		memory32 = &resource->data.memory32;
> -		addr->resource_type = ACPI_MEMORY_RANGE;
> -		addr->address.minimum = memory32->minimum;
> -		addr->address.address_length = memory32->address_length;
> -		addr->address.maximum = addr->address.minimum + addr->address.address_length - 1;
> -		return AE_OK;
> -	case ACPI_RESOURCE_TYPE_FIXED_MEMORY32:
> -		fixed_memory32 = &resource->data.fixed_memory32;
> -		addr->resource_type = ACPI_MEMORY_RANGE;
> -		addr->address.minimum = fixed_memory32->address;
> -		addr->address.address_length = fixed_memory32->address_length;
> -		addr->address.maximum = addr->address.minimum + addr->address.address_length - 1;
> -		return AE_OK;
> -	case ACPI_RESOURCE_TYPE_ADDRESS16:
> -	case ACPI_RESOURCE_TYPE_ADDRESS32:
> -	case ACPI_RESOURCE_TYPE_ADDRESS64:
> -		status = acpi_resource_to_address64(resource, addr);
> -		if (ACPI_SUCCESS(status) &&
> -		    (addr->resource_type == ACPI_MEMORY_RANGE ||
> -		    addr->resource_type == ACPI_IO_RANGE) &&
> -		    addr->address.address_length > 0) {
> -			return AE_OK;
> -		}
> -		break;
> -	}
> -	return AE_ERROR;
> -}
> -
> -static acpi_status count_resource(struct acpi_resource *acpi_res, void *data)
> +static void validate_resources(struct device *dev, struct list_head *crs_res,
> +			       unsigned long type)
>  {
> -	struct pci_root_info *info = data;
> -	struct acpi_resource_address64 addr;
> -	acpi_status status;
> -
> -	status = resource_to_addr(acpi_res, &addr);
> -	if (ACPI_SUCCESS(status))
> -		info->res_num++;
> -	return AE_OK;
> -}
> -
> -static acpi_status setup_resource(struct acpi_resource *acpi_res, void *data)
> -{
> -	struct pci_root_info *info = data;
> -	struct resource *res;
> -	struct acpi_resource_address64 addr;
> -	acpi_status status;
> -	unsigned long flags;
> -	u64 start, orig_end, end;
> -
> -	status = resource_to_addr(acpi_res, &addr);
> -	if (!ACPI_SUCCESS(status))
> -		return AE_OK;
> -
> -	if (addr.resource_type == ACPI_MEMORY_RANGE) {
> -		flags = IORESOURCE_MEM;
> -		if (addr.info.mem.caching == ACPI_PREFETCHABLE_MEMORY)
> -			flags |= IORESOURCE_PREFETCH;
> -	} else if (addr.resource_type == ACPI_IO_RANGE) {
> -		flags = IORESOURCE_IO;
> -	} else
> -		return AE_OK;
> -
> -	start = addr.address.minimum + addr.address.translation_offset;
> -	orig_end = end = addr.address.maximum + addr.address.translation_offset;
> -
> -	/* Exclude non-addressable range or non-addressable portion of range */
> -	end = min(end, (u64)iomem_resource.end);
> -	if (end <= start) {
> -		dev_info(&info->bridge->dev,
> -			"host bridge window [%#llx-%#llx] "
> -			"(ignored, not CPU addressable)\n", start, orig_end);
> -		return AE_OK;
> -	} else if (orig_end != end) {
> -		dev_info(&info->bridge->dev,
> -			"host bridge window [%#llx-%#llx] "
> -			"([%#llx-%#llx] ignored, not CPU addressable)\n", 
> -			start, orig_end, end + 1, orig_end);
> -	}
> +	LIST_HEAD(list);
> +	struct resource *res1, *res2, *root = NULL;
> +	struct resource_list_entry *tmp, *entry, *entry2;
>  
> -	res = &info->res[info->res_num];
> -	res->name = info->name;
> -	res->flags = flags;
> -	res->start = start;
> -	res->end = end;
> -	info->res_offset[info->res_num] = addr.address.translation_offset;
> -	info->res_num++;
> +	BUG_ON((type & (IORESOURCE_MEM | IORESOURCE_IO)) == 0);
> +	root = (type & IORESOURCE_MEM) ? &iomem_resource : &ioport_resource;
>  
> -	if (!pci_use_crs)
> -		dev_printk(KERN_DEBUG, &info->bridge->dev,
> -			   "host bridge window %pR (ignored)\n", res);
> +	list_splice_init(crs_res, &list);
> +	resource_list_for_each_entry_safe(entry, tmp, &list) {
> +		bool free = false;
> +		resource_size_t end;
>  
> -	return AE_OK;
> -}
> -
> -static void coalesce_windows(struct pci_root_info *info, unsigned long type)
> -{
> -	int i, j;
> -	struct resource *res1, *res2;
> -
> -	for (i = 0; i < info->res_num; i++) {
> -		res1 = &info->res[i];
> +		res1 = entry->res;
>  		if (!(res1->flags & type))
> -			continue;
> +			goto next;
> +
> +		/* Exclude non-addressable range or non-addressable portion */
> +		end = min(res1->end, root->end);
> +		if (end <= res1->start) {
> +			dev_info(dev, "host bridge window [%#llx-%#llx] (ignored, not CPU addressable)\n",
> +				 (unsigned long long)res1->start,
> +				 (unsigned long long)res1->end);
> +			free = true;
> +			goto next;
> +		} else if (res1->end != end) {
> +			dev_info(dev, "host bridge window [%#llx-%#llx] ([%#llx-%#llx] ignored, not CPU addressable)\n",
> +				 (unsigned long long)res1->start,
> +				 (unsigned long long)res1->end,
> +				 (unsigned long long)end + 1,
> +				 (unsigned long long)res1->end);
> +			res1->end = end;
> +		}
>  
> -		for (j = i + 1; j < info->res_num; j++) {
> -			res2 = &info->res[j];
> +		resource_list_for_each_entry(entry2, crs_res) {
> +			res2 = entry2->res;
>  			if (!(res2->flags & type))
>  				continue;
>  
> @@ -353,118 +264,92 @@ static void coalesce_windows(struct pci_root_info *info, unsigned long type)
>  			if (resource_overlaps(res1, res2)) {
>  				res2->start = min(res1->start, res2->start);
>  				res2->end = max(res1->end, res2->end);
> -				dev_info(&info->bridge->dev,
> -					 "host bridge window expanded to %pR; %pR ignored\n",
> +				dev_info(dev, "host bridge window expanded to %pR; %pR ignored\n",
>  					 res2, res1);
> -				res1->flags = 0;
> +				free = true;
> +				goto next;
>  			}
>  		}
> +
> +next:
> +		resource_list_del(entry);
> +		if (free)
> +			resource_list_free_entry(entry);
> +		else
> +			resource_list_add_tail(entry, crs_res);
>  	}
>  }
>  
>  static void add_resources(struct pci_root_info *info,
> -			  struct list_head *resources)
> +			  struct list_head *resources,
> +			  struct list_head *crs_res)
>  {
> -	int i;
> -	struct resource *res, *root, *conflict;
> -
> -	coalesce_windows(info, IORESOURCE_MEM);
> -	coalesce_windows(info, IORESOURCE_IO);
> +	struct resource_list_entry *entry, *tmp;
> +	struct resource *res, *conflict, *root = NULL;
>  
> -	for (i = 0; i < info->res_num; i++) {
> -		res = &info->res[i];
> +	validate_resources(&info->bridge->dev, crs_res, IORESOURCE_MEM);
> +	validate_resources(&info->bridge->dev, crs_res, IORESOURCE_IO);
>  
> +	resource_list_for_each_entry_safe(entry, tmp, crs_res) {
> +		res = entry->res;
>  		if (res->flags & IORESOURCE_MEM)
>  			root = &iomem_resource;
>  		else if (res->flags & IORESOURCE_IO)
>  			root = &ioport_resource;
>  		else
> -			continue;
> +			BUG_ON(res);
>  
>  		conflict = insert_resource_conflict(root, res);
> -		if (conflict)
> +		if (conflict) {
>  			dev_info(&info->bridge->dev,
>  				 "ignoring host bridge window %pR (conflicts with %s %pR)\n",
>  				 res, conflict->name, conflict);
> -		else
> -			pci_add_resource_offset(resources, res,
> -					info->res_offset[i]);
> +			resource_list_destroy_entry(entry);
> +		}
>  	}
> -}
>  
> -static void free_pci_root_info_res(struct pci_root_info *info)
> -{
> -	kfree(info->res);
> -	info->res = NULL;
> -	kfree(info->res_offset);
> -	info->res_offset = NULL;
> -	info->res_num = 0;
> +	list_splice_tail(crs_res, resources);
>  }
>  
> -static void __release_pci_root_info(struct pci_root_info *info)
> +static void release_pci_root_info(struct pci_host_bridge *bridge)
>  {
> -	int i;
>  	struct resource *res;
> +	struct resource_list_entry *entry;
> +	struct pci_root_info *info = bridge->release_data;
>  
> -	for (i = 0; i < info->res_num; i++) {
> -		res = &info->res[i];
> -
> -		if (!res->parent)
> -			continue;
> -
> -		if (!(res->flags & (IORESOURCE_MEM | IORESOURCE_IO)))
> -			continue;
> -
> -		release_resource(res);
> +	resource_list_for_each_entry(entry, &bridge->windows) {
> +		res = entry->res;
> +		if (res->parent &&
> +		    (res->flags & (IORESOURCE_MEM | IORESOURCE_IO)))
> +			release_resource(res);
>  	}
>  
> -	free_pci_root_info_res(info);
> -
>  	teardown_mcfg_map(info);
> -
>  	kfree(info);
>  }
>  
> -static void release_pci_root_info(struct pci_host_bridge *bridge)
> -{
> -	struct pci_root_info *info = bridge->release_data;
> -
> -	__release_pci_root_info(info);
> -}
> -
>  static void probe_pci_root_info(struct pci_root_info *info,
>  				struct acpi_device *device,
> -				int busnum, int domain)
> +				int busnum, int domain,
> +				struct list_head *list)
>  {
> -	size_t size;
> +	int ret;
> +	struct resource_list_entry *entry;
>  
>  	sprintf(info->name, "PCI Bus %04x:%02x", domain, busnum);
>  	info->bridge = device;
> -
> -	info->res_num = 0;
> -	acpi_walk_resources(device->handle, METHOD_NAME__CRS, count_resource,
> -				info);
> -	if (!info->res_num)
> -		return;
> -
> -	size = sizeof(*info->res) * info->res_num;
> -	info->res = kzalloc_node(size, GFP_KERNEL, info->sd.node);
> -	if (!info->res) {
> -		info->res_num = 0;
> -		return;
> -	}
> -
> -	size = sizeof(*info->res_offset) * info->res_num;
> -	info->res_num = 0;
> -	info->res_offset = kzalloc_node(size, GFP_KERNEL, info->sd.node);
> -	if (!info->res_offset) {
> -		kfree(info->res);
> -		info->res = NULL;
> -		return;
> -	}
> -
> -	acpi_walk_resources(device->handle, METHOD_NAME__CRS, setup_resource,
> -				info);
> +	ret = acpi_dev_get_resources(device, list,
> +				     acpi_dev_filter_resource_type_cb,
> +				     (void *)(IORESOURCE_IO | IORESOURCE_MEM));
> +	if (ret < 0)
> +		dev_warn(&device->dev,
> +			 "failed to parse _CRS method, error code %d.\n", ret);
> +	else if (ret == 0)
> +		dev_dbg(&device->dev,
> +			"no IO and memory resources present in _CRS.\n");
> +	else
> +		resource_list_for_each_entry(entry, list)
> +			entry->res->name = info->name;
>  }
>  
>  struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
> @@ -473,6 +358,8 @@ struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
>  	struct pci_root_info *info;
>  	int domain = root->segment;
>  	int busnum = root->secondary.start;
> +	struct resource_list_entry *res_entry;
> +	LIST_HEAD(crs_res);
>  	LIST_HEAD(resources);
>  	struct pci_bus *bus;
>  	struct pci_sysdata *sd;
> @@ -520,18 +407,22 @@ struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
>  		memcpy(bus->sysdata, sd, sizeof(*sd));
>  		kfree(info);
>  	} else {
> -		probe_pci_root_info(info, device, busnum, domain);
> -
>  		/* insert busn res at first */
>  		pci_add_resource(&resources,  &root->secondary);
> +
>  		/*
>  		 * _CRS with no apertures is normal, so only fall back to
>  		 * defaults or native bridge info if we're ignoring _CRS.
>  		 */
> -		if (pci_use_crs)
> -			add_resources(info, &resources);
> -		else {
> -			free_pci_root_info_res(info);
> +		probe_pci_root_info(info, device, busnum, domain, &crs_res);
> +		if (pci_use_crs) {
> +			add_resources(info, &resources, &crs_res);
> +		} else {
> +			resource_list_for_each_entry(res_entry, &crs_res)
> +				dev_printk(KERN_DEBUG, &device->dev,
> +					   "host bridge window %pR (ignored)\n",
> +					   res_entry->res);
> +			resource_list_free(&crs_res);
>  			x86_pci_root_bus_resources(busnum, &resources);
>  		}
>  
> @@ -546,8 +437,9 @@ struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
>  				to_pci_host_bridge(bus->bridge),
>  				release_pci_root_info, info);
>  		} else {
> -			pci_free_resource_list(&resources);
> -			__release_pci_root_info(info);
> +			resource_list_free(&resources);
> +			teardown_mcfg_map(info);
> +			kfree(info);
>  		}
>  	}
>  
> -- 
> 1.7.10.4
>