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

[Jiang Liu]

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.

Signed-off-by: Jiang Liu <jiang.liu@xxxxxxxxxxxxxxx>
---
 arch/x86/pci/acpi.c |  297 ++++++++++++++++-----------------------------------
 1 file changed, 95 insertions(+), 202 deletions(-)

diff --git a/arch/x86/pci/acpi.c b/arch/x86/pci/acpi.c
index cfd1b132b8e3..749266c8c671 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->minimum = memory24->minimum;
-		addr->address_length = memory24->address_length;
-		addr->maximum = addr->minimum + addr->address_length - 1;
-		return AE_OK;
-	case ACPI_RESOURCE_TYPE_MEMORY32:
-		memory32 = &resource->data.memory32;
-		addr->resource_type = ACPI_MEMORY_RANGE;
-		addr->minimum = memory32->minimum;
-		addr->address_length = memory32->address_length;
-		addr->maximum = addr->minimum + addr->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->minimum = fixed_memory32->address;
-		addr->address_length = fixed_memory32->address_length;
-		addr->maximum = addr->minimum + addr->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_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.minimum + addr.translation_offset;
-	orig_end = end = addr.maximum + addr.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.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 +264,93 @@ 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_delete(entry);
+		if (free)
+			resource_list_free(entry);
+		else
+			resource_list_insert(crs_res, entry, true);
 	}
 }
 
 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_delete(entry);
+			resource_list_free(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,
+				     (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 +359,8 @@ 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 +408,22 @@ 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_list(&crs_res);
 			x86_pci_root_bus_resources(busnum, &resources);
 		}
 
@@ -546,8 +438,9 @@ 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_list(&resources);
+			teardown_mcfg_map(info);
+			kfree(info);
 		}
 	}
 
-- 
1.7.10.4

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