Merge branch 'pci/resource'

- Prevent assigning space to unimplemented bridge windows; previously we
  mistakenly assumed prefetchable window existed and assigned space and put
  a BAR there (Ahmed Naseef)

- Avoid shrinking bridge windows to fit in the initial Root Port window;
  this fixes one problem with devices with large BARs connected via
  switches, e.g., Thunderbolt (Ilpo Järvinen)

- Retain information about optional resources to make assignment during
  rescan more likely to succeed (Ilpo Järvinen)

- Add __resource_contains_unbound() for use in finding space for resources
  with no address assigned (Ilpo Järvinen)

- Pass full extent of empty space, not just the aligned space, to
  resource_alignf callback so free space before the requested alignment can
  be used (Ilpo Järvinen)

- Remove unnecessary second alignment from ARM, m68k, MIPS (Ilpo Järvinen)

- Place small resources before larger ones for better utilization of
  address space (Ilpo Järvinen)

- Fix alignment calculation for resource size larger than align, e.g.,
  bridge windows larger than the 1MB required alignment (Ilpo Järvinen)

* pci/resource:
  PCI: Fix alignment calculation for resource size larger than align
  PCI: Align head space better
  PCI: Rename window_alignment() to pci_min_window_alignment()
  parisc/PCI: Clean up align handling
  MIPS: PCI: Remove unnecessary second application of align
  m68k/PCI: Remove unnecessary second application of align
  ARM/PCI: Remove unnecessary second application of align
  resource: Rename 'tmp' variable to 'full_avail'
  resource: Pass full extent of empty space to resource_alignf callback
  resource: Add __resource_contains_unbound() for internal contains checks
  PCI: Fix premature removal from realloc_head list during resource assignment
  PCI: Prevent shrinking bridge window from its required size
  PCI: Prevent assignment to unsupported bridge windows

4 files changed, 103 insertions, 11 deletions

diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index a1d2ecb56207..9540f1f1709a 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -1053,6 +1053,9 @@ static inline resource_size_t pci_resource_alignment(struct pci_dev *dev,
 	return resource_alignment(res);
 }
 
+resource_size_t pci_min_window_alignment(struct pci_bus *bus,
+					 unsigned long type);
+
 void pci_acs_init(struct pci_dev *dev);
 void pci_enable_acs(struct pci_dev *dev);
 #ifdef CONFIG_PCI_QUIRKS
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 19d73f6132fb..675713548431 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -378,6 +378,9 @@ static void pci_read_bridge_io(struct pci_dev *dev, struct resource *res,
 	unsigned long io_mask, io_granularity, base, limit;
 	struct pci_bus_region region;
 
+	if (!dev->io_window)
+		return;
+
 	io_mask = PCI_IO_RANGE_MASK;
 	io_granularity = 0x1000;
 	if (dev->io_window_1k) {
@@ -448,6 +451,9 @@ static void pci_read_bridge_mmio_pref(struct pci_dev *dev, struct resource *res,
 	pci_bus_addr_t base, limit;
 	struct pci_bus_region region;
 
+	if (!dev->pref_window)
+		return;
+
 	pci_read_config_word(dev, PCI_PREF_MEMORY_BASE, &mem_base_lo);
 	pci_read_config_word(dev, PCI_PREF_MEMORY_LIMIT, &mem_limit_lo);
 	base64 = (mem_base_lo & PCI_PREF_RANGE_MASK) << 16;
diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index 61f769aaa2f6..4cf120ebe5ad 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -434,6 +434,10 @@ static void reassign_resources_sorted(struct list_head *realloc_head,
 		dev = add_res->dev;
 		idx = pci_resource_num(dev, res);
 
+		/* Skip this resource if not found in head list */
+		if (!res_to_dev_res(head, res))
+			continue;
+
 		/*
 		 * Skip resource that failed the earlier assignment and is
 		 * not optional as it would just fail again.
@@ -442,10 +446,6 @@ static void reassign_resources_sorted(struct list_head *realloc_head,
 		    !pci_resource_is_optional(dev, idx))
 			goto out;
 
-		/* Skip this resource if not found in head list */
-		if (!res_to_dev_res(head, res))
-			continue;
-
 		res_name = pci_resource_name(dev, idx);
 		add_size = add_res->add_size;
 		align = add_res->min_align;
@@ -1035,7 +1035,7 @@ resource_size_t __weak pcibios_window_alignment(struct pci_bus *bus,
 #define PCI_P2P_DEFAULT_IO_ALIGN	SZ_4K
 #define PCI_P2P_DEFAULT_IO_ALIGN_1K	SZ_1K
 
-static resource_size_t window_alignment(struct pci_bus *bus, unsigned long type)
+resource_size_t pci_min_window_alignment(struct pci_bus *bus, unsigned long type)
 {
 	resource_size_t align = 1, arch_align;
 
@@ -1084,7 +1084,7 @@ static void pbus_size_io(struct pci_bus *bus, resource_size_t add_size,
 	if (resource_assigned(b_res))
 		return;
 
-	min_align = window_alignment(bus, IORESOURCE_IO);
+	min_align = pci_min_window_alignment(bus, IORESOURCE_IO);
 	list_for_each_entry(dev, &bus->devices, bus_list) {
 		struct resource *r;
 
@@ -1333,13 +1333,20 @@ static void pbus_size_mem(struct pci_bus *bus, struct resource *b_res,
 			r_size = resource_size(r);
 			size += max(r_size, align);
 
-			aligns[order] += align;
+			/*
+			 * If resource's size is larger than its alignment,
+			 * some configurations result in an unwanted gap in
+			 * the head space that the larger resource cannot
+			 * fill.
+			 */
+			if (r_size <= align)
+				aligns[order] += align;
 			if (order > max_order)
 				max_order = order;
 		}
 	}
 
-	win_align = window_alignment(bus, b_res->flags);
+	win_align = pci_min_window_alignment(bus, b_res->flags);
 	min_align = calculate_head_align(aligns, max_order);
 	min_align = max(min_align, win_align);
 	size0 = calculate_memsize(size, realloc_head ? 0 : add_size,
@@ -1837,6 +1844,7 @@ static void adjust_bridge_window(struct pci_dev *bridge, struct resource *res,
 				 resource_size_t new_size)
 {
 	resource_size_t add_size, size = resource_size(res);
+	struct pci_dev_resource *dev_res;
 
 	if (resource_assigned(res))
 		return;
@@ -1849,9 +1857,46 @@ static void adjust_bridge_window(struct pci_dev *bridge, struct resource *res,
 		pci_dbg(bridge, "bridge window %pR extended by %pa\n", res,
 			&add_size);
 	} else if (new_size < size) {
+		int idx = pci_resource_num(bridge, res);
+
+		/*
+		 * hpio/mmio/mmioprefsize hasn't been included at all? See the
+		 * add_size param at the callsites of calculate_memsize().
+		 */
+		if (!add_list)
+			return;
+
+		/* Only shrink if the hotplug extra relates to window size. */
+		switch (idx) {
+			case PCI_BRIDGE_IO_WINDOW:
+				if (size > pci_hotplug_io_size)
+					return;
+				break;
+			case PCI_BRIDGE_MEM_WINDOW:
+				if (size > pci_hotplug_mmio_size)
+					return;
+				break;
+			case PCI_BRIDGE_PREF_MEM_WINDOW:
+				if (size > pci_hotplug_mmio_pref_size)
+					return;
+				break;
+			default:
+				break;
+		}
+
+		dev_res = res_to_dev_res(add_list, res);
 		add_size = size - new_size;
-		pci_dbg(bridge, "bridge window %pR shrunken by %pa\n", res,
-			&add_size);
+		if (add_size < dev_res->add_size) {
+			dev_res->add_size -= add_size;
+			pci_dbg(bridge, "bridge window %pR optional size shrunken by %pa\n",
+				res, &add_size);
+		} else {
+			pci_dbg(bridge, "bridge window %pR optional size removed\n",
+				res);
+			pci_dev_res_remove_from_list(add_list, res);
+		}
+		return;
+
 	} else {
 		return;
 	}
diff --git a/drivers/pci/setup-res.c b/drivers/pci/setup-res.c
index bb2aef373d6f..fbc05cda96ee 100644
--- a/drivers/pci/setup-res.c
+++ b/drivers/pci/setup-res.c
@@ -245,16 +245,54 @@ static int pci_revert_fw_address(struct resource *res, struct pci_dev *dev,
 }
 
 /*
+ * For mem bridge windows, try to relocate tail remainder space to space
+ * before res->start if there's enough free space there. This enables
+ * tighter packing for resources.
+ */
+resource_size_t pci_align_resource(struct pci_dev *dev,
+				   const struct resource *res,
+				   const struct resource *empty_res,
+				   resource_size_t size,
+				   resource_size_t align)
+{
+	resource_size_t remainder, start_addr;
+
+	if (!(res->flags & IORESOURCE_MEM))
+		return res->start;
+
+	if (IS_ALIGNED(size, align))
+		return res->start;
+
+	remainder = size - ALIGN_DOWN(size, align);
+	/* Don't mess with size that doesn't align with window size granularity */
+	if (!IS_ALIGNED(remainder, pci_min_window_alignment(dev->bus, res->flags)))
+		return res->start;
+	/* Try to place remainder that doesn't fill align before */
+	if (res->start < remainder)
+		return res->start;
+	start_addr = res->start - remainder;
+	if (empty_res->start > start_addr)
+		return res->start;
+
+	pci_dbg(dev, "%pR: moving candidate start address below align to %llx\n",
+		res, (unsigned long long)start_addr);
+	return start_addr;
+}
+
+/*
  * We don't have to worry about legacy ISA devices, so nothing to do here.
  * This is marked as __weak because multiple architectures define it; it should
  * eventually go away.
  */
 resource_size_t __weak pcibios_align_resource(void *data,
 					      const struct resource *res,
+					      const struct resource *empty_res,
 					      resource_size_t size,
 					      resource_size_t align)
 {
-       return res->start;
+	struct pci_dev *dev = data;
+
+	return pci_align_resource(dev, res, empty_res, size, align);
 }
 
 static int __pci_assign_resource(struct pci_bus *bus, struct pci_dev *dev,