From edfaa81d5da5fbfe3c73fece3ca0417a04cc4ba2 Mon Sep 17 00:00:00 2001
From: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Date: Tue, 24 Mar 2026 18:56:24 +0200
Subject: resource: Add __resource_contains_unbound() for internal contains
 checks
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

__find_resource_space() currently uses resource_contains() but for
tentative resources that are not yet crafted into the resource tree. As
resource_contains() checks that IORESOURCE_UNSET is not set for either of
the resources, the caller has to hack around this problem by clearing the
IORESOURCE_UNSET flag (essentially lying to resource_contains()).

Instead of the hack, introduce __resource_contains_unbound() for cases like
this.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Xifer <xiferdev@gmail.com>
Link: https://patch.msgid.link/20260324165633.4583-2-ilpo.jarvinen@linux.intel.com
---
 include/linux/ioport.h | 20 +++++++++++++++++---
 1 file changed, 17 insertions(+), 3 deletions(-)

(limited to 'include/linux')

diff --git a/include/linux/ioport.h b/include/linux/ioport.h
index 5533a5debf3f..19d5e04564d9 100644
--- a/include/linux/ioport.h
+++ b/include/linux/ioport.h
@@ -304,14 +304,28 @@ static inline unsigned long resource_ext_type(const struct resource *res)
 {
 	return res->flags & IORESOURCE_EXT_TYPE_BITS;
 }
-/* True iff r1 completely contains r2 */
-static inline bool resource_contains(const struct resource *r1, const struct resource *r2)
+
+/*
+ * For checking if @r1 completely contains @r2 for resources that have real
+ * addresses but are not yet crafted into the resource tree. Normally
+ * resource_contains() should be used instead of this function as it checks
+ * also IORESOURCE_UNSET flag.
+ */
+static inline bool __resource_contains_unbound(const struct resource *r1,
+					       const struct resource *r2)
 {
 	if (resource_type(r1) != resource_type(r2))
 		return false;
+
+	return r1->start <= r2->start && r1->end >= r2->end;
+}
+/* True iff r1 completely contains r2 */
+static inline bool resource_contains(const struct resource *r1, const struct resource *r2)
+{
 	if (r1->flags & IORESOURCE_UNSET || r2->flags & IORESOURCE_UNSET)
 		return false;
-	return r1->start <= r2->start && r1->end >= r2->end;
+
+	return __resource_contains_unbound(r1, r2);
 }
 
 /* True if any part of r1 overlaps r2 */
-- 
cgit v1.2.3


From f699bcc8bcdf99565928a7b1fc7ee656f6c81815 Mon Sep 17 00:00:00 2001
From: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Date: Tue, 24 Mar 2026 18:56:25 +0200
Subject: resource: Pass full extent of empty space to resource_alignf callback
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

__find_resource_space() calculates the full extent of empty space but only
passes the aligned space to resource_alignf callback. In some situations,
the callback may choose take advantage of the free space before the
requested alignment.

Pass the full extent of the calculated empty space to resource_alignf
callback as an additional parameter.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Xifer <xiferdev@gmail.com>
Link: https://patch.msgid.link/20260324165633.4583-3-ilpo.jarvinen@linux.intel.com
---
 arch/alpha/kernel/pci.c          | 1 +
 arch/arm/kernel/bios32.c         | 4 +++-
 arch/m68k/kernel/pcibios.c       | 4 +++-
 arch/mips/pci/pci-generic.c      | 3 ++-
 arch/mips/pci/pci-legacy.c       | 1 +
 arch/parisc/kernel/pci.c         | 4 +++-
 arch/powerpc/kernel/pci-common.c | 4 +++-
 arch/s390/pci/pci.c              | 1 +
 arch/sh/drivers/pci/pci.c        | 4 +++-
 arch/x86/pci/i386.c              | 3 ++-
 arch/xtensa/kernel/pci.c         | 1 +
 drivers/pci/setup-res.c          | 3 ++-
 drivers/pcmcia/rsrc_nonstatic.c  | 3 ++-
 include/linux/ioport.h           | 2 ++
 include/linux/pci.h              | 7 ++++---
 kernel/resource.c                | 3 ++-
 16 files changed, 35 insertions(+), 13 deletions(-)

(limited to 'include/linux')

diff --git a/arch/alpha/kernel/pci.c b/arch/alpha/kernel/pci.c
index 51a8a4c4572a..11df411b1d18 100644
--- a/arch/alpha/kernel/pci.c
+++ b/arch/alpha/kernel/pci.c
@@ -125,6 +125,7 @@ DECLARE_PCI_FIXUP_FINAL(PCI_ANY_ID, PCI_ANY_ID, pcibios_fixup_final);
 
 resource_size_t
 pcibios_align_resource(void *data, const struct resource *res,
+		       const struct resource *empty_res,
 		       resource_size_t size, resource_size_t align)
 {
 	struct pci_dev *dev = data;
diff --git a/arch/arm/kernel/bios32.c b/arch/arm/kernel/bios32.c
index b5793e8fbdc1..5b9b4fcd0e54 100644
--- a/arch/arm/kernel/bios32.c
+++ b/arch/arm/kernel/bios32.c
@@ -560,7 +560,9 @@ char * __init pcibios_setup(char *str)
  * which might be mirrored at 0x0100-0x03ff..
  */
 resource_size_t pcibios_align_resource(void *data, const struct resource *res,
-				resource_size_t size, resource_size_t align)
+				       const struct resource *empty_res,
+				       resource_size_t size,
+				       resource_size_t align)
 {
 	struct pci_dev *dev = data;
 	resource_size_t start = res->start;
diff --git a/arch/m68k/kernel/pcibios.c b/arch/m68k/kernel/pcibios.c
index e6ab3f9ff5d8..1415f6e4e5ce 100644
--- a/arch/m68k/kernel/pcibios.c
+++ b/arch/m68k/kernel/pcibios.c
@@ -27,7 +27,9 @@
  * which might be mirrored at 0x0100-0x03ff..
  */
 resource_size_t pcibios_align_resource(void *data, const struct resource *res,
-	resource_size_t size, resource_size_t align)
+				       const struct resource *empty_res,
+				       resource_size_t size,
+				       resource_size_t align)
 {
 	resource_size_t start = res->start;
 
diff --git a/arch/mips/pci/pci-generic.c b/arch/mips/pci/pci-generic.c
index d2d68bac3d25..f4957c26efc7 100644
--- a/arch/mips/pci/pci-generic.c
+++ b/arch/mips/pci/pci-generic.c
@@ -22,7 +22,8 @@
  * which might have be mirrored at 0x0100-0x03ff..
  */
 resource_size_t pcibios_align_resource(void *data, const struct resource *res,
-				resource_size_t size, resource_size_t align)
+				       const struct resource *empty_res,
+				       resource_size_t size, resource_size_t align)
 {
 	struct pci_dev *dev = data;
 	resource_size_t start = res->start;
diff --git a/arch/mips/pci/pci-legacy.c b/arch/mips/pci/pci-legacy.c
index d04b7c1294b6..817e97402afe 100644
--- a/arch/mips/pci/pci-legacy.c
+++ b/arch/mips/pci/pci-legacy.c
@@ -52,6 +52,7 @@ unsigned long pci_address_to_pio(phys_addr_t address)
  */
 resource_size_t
 pcibios_align_resource(void *data, const struct resource *res,
+		       const struct resource *empty_res,
 		       resource_size_t size, resource_size_t align)
 {
 	struct pci_dev *dev = data;
diff --git a/arch/parisc/kernel/pci.c b/arch/parisc/kernel/pci.c
index cf285b17a5ae..f99b20795d5a 100644
--- a/arch/parisc/kernel/pci.c
+++ b/arch/parisc/kernel/pci.c
@@ -196,7 +196,9 @@ void __ref pcibios_init_bridge(struct pci_dev *dev)
  * than res->start.
  */
 resource_size_t pcibios_align_resource(void *data, const struct resource *res,
-				resource_size_t size, resource_size_t alignment)
+				       const struct resource *empty_res,
+				       resource_size_t size,
+				       resource_size_t alignment)
 {
 	resource_size_t mask, align, start = res->start;
 
diff --git a/arch/powerpc/kernel/pci-common.c b/arch/powerpc/kernel/pci-common.c
index a7a2fb605971..e7bfa15da043 100644
--- a/arch/powerpc/kernel/pci-common.c
+++ b/arch/powerpc/kernel/pci-common.c
@@ -1132,7 +1132,9 @@ static int skip_isa_ioresource_align(struct pci_dev *dev)
  * which might have be mirrored at 0x0100-0x03ff..
  */
 resource_size_t pcibios_align_resource(void *data, const struct resource *res,
-				resource_size_t size, resource_size_t align)
+				       const struct resource *empty_res,
+				       resource_size_t size,
+				       resource_size_t align)
 {
 	struct pci_dev *dev = data;
 	resource_size_t start = res->start;
diff --git a/arch/s390/pci/pci.c b/arch/s390/pci/pci.c
index 2a430722cbe4..39bd2adfc240 100644
--- a/arch/s390/pci/pci.c
+++ b/arch/s390/pci/pci.c
@@ -266,6 +266,7 @@ static int zpci_cfg_store(struct zpci_dev *zdev, int offset, u32 val, u8 len)
 }
 
 resource_size_t pcibios_align_resource(void *data, const struct resource *res,
+				       const struct resource *empty_res,
 				       resource_size_t size,
 				       resource_size_t align)
 {
diff --git a/arch/sh/drivers/pci/pci.c b/arch/sh/drivers/pci/pci.c
index a3903304f33f..7a0522316ee3 100644
--- a/arch/sh/drivers/pci/pci.c
+++ b/arch/sh/drivers/pci/pci.c
@@ -168,7 +168,9 @@ subsys_initcall(pcibios_init);
  * modulo 0x400.
  */
 resource_size_t pcibios_align_resource(void *data, const struct resource *res,
-				resource_size_t size, resource_size_t align)
+				       const struct resource *empty_res,
+				       resource_size_t size,
+				       resource_size_t align)
 {
 	struct pci_dev *dev = data;
 	struct pci_channel *hose = dev->sysdata;
diff --git a/arch/x86/pci/i386.c b/arch/x86/pci/i386.c
index c4ec39ad276b..6fbd4b34c3f7 100644
--- a/arch/x86/pci/i386.c
+++ b/arch/x86/pci/i386.c
@@ -153,7 +153,8 @@ skip_isa_ioresource_align(struct pci_dev *dev) {
  */
 resource_size_t
 pcibios_align_resource(void *data, const struct resource *res,
-			resource_size_t size, resource_size_t align)
+		       const struct resource *empty_res,
+		       resource_size_t size, resource_size_t align)
 {
 	struct pci_dev *dev = data;
 	resource_size_t start = res->start;
diff --git a/arch/xtensa/kernel/pci.c b/arch/xtensa/kernel/pci.c
index 62c900e400d6..64ccb7e0d92f 100644
--- a/arch/xtensa/kernel/pci.c
+++ b/arch/xtensa/kernel/pci.c
@@ -39,6 +39,7 @@
  */
 resource_size_t
 pcibios_align_resource(void *data, const struct resource *res,
+		       const struct resource *empty_res,
 		       resource_size_t size, resource_size_t align)
 {
 	struct pci_dev *dev = data;
diff --git a/drivers/pci/setup-res.c b/drivers/pci/setup-res.c
index bb2aef373d6f..c375e255c509 100644
--- a/drivers/pci/setup-res.c
+++ b/drivers/pci/setup-res.c
@@ -251,10 +251,11 @@ static int pci_revert_fw_address(struct resource *res, struct pci_dev *dev,
  */
 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;
+	return res->start;
 }
 
 static int __pci_assign_resource(struct pci_bus *bus, struct pci_dev *dev,
diff --git a/drivers/pcmcia/rsrc_nonstatic.c b/drivers/pcmcia/rsrc_nonstatic.c
index 0679dd434719..949e69921fe9 100644
--- a/drivers/pcmcia/rsrc_nonstatic.c
+++ b/drivers/pcmcia/rsrc_nonstatic.c
@@ -602,7 +602,8 @@ static resource_size_t pcmcia_common_align(struct pcmcia_align_data *align_data,
 
 static resource_size_t
 pcmcia_align(void *align_data, const struct resource *res,
-	resource_size_t size, resource_size_t align)
+	     const struct resource *empty_res,
+	     resource_size_t size, resource_size_t align)
 {
 	struct pcmcia_align_data *data = align_data;
 	struct resource_map *m;
diff --git a/include/linux/ioport.h b/include/linux/ioport.h
index 19d5e04564d9..3c73c9c0d4f7 100644
--- a/include/linux/ioport.h
+++ b/include/linux/ioport.h
@@ -202,6 +202,7 @@ enum {
  * typedef resource_alignf - Resource alignment callback
  * @data:	Private data used by the callback
  * @res:	Resource candidate range (an empty resource space)
+ * @empty_res:	Empty resource range without alignment applied
  * @size:	The minimum size of the empty space
  * @align:	Alignment from the constraints
  *
@@ -212,6 +213,7 @@ enum {
  */
 typedef resource_size_t (*resource_alignf)(void *data,
 					   const struct resource *res,
+					   const struct resource *empty_res,
 					   resource_size_t size,
 					   resource_size_t align);
 
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 1c270f1d5123..ac332ff9da9f 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1206,9 +1206,10 @@ int __must_check pcibios_enable_device(struct pci_dev *, int mask);
 char *pcibios_setup(char *str);
 
 /* Used only when drivers/pci/setup.c is used */
-resource_size_t pcibios_align_resource(void *, const struct resource *,
-				resource_size_t,
-				resource_size_t);
+resource_size_t pcibios_align_resource(void *data, const struct resource *res,
+				       const struct resource *empty_res,
+				       resource_size_t size,
+				       resource_size_t align);
 
 /* Generic PCI functions used internally */
 
diff --git a/kernel/resource.c b/kernel/resource.c
index 1e2f1dfc0edd..1b8d3101bdc6 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -759,7 +759,8 @@ static int __find_resource_space(struct resource *root, struct resource *old,
 			alloc.flags = avail.flags;
 			if (alignf) {
 				alloc.start = alignf(constraint->alignf_data,
-						     &avail, size, constraint->align);
+						     &avail, &tmp,
+						     size, constraint->align);
 			} else {
 				alloc.start = avail.start;
 			}
-- 
cgit v1.2.3


From 9036bd0efcb6162a77f3bf9bacbafba7686c7275 Mon Sep 17 00:00:00 2001
From: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Date: Tue, 24 Mar 2026 18:56:32 +0200
Subject: PCI: Align head space better
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

When a bridge window contains big and small resource(s), the small
resource(s) may not amount to the half of the size of the big resource
which would allow calculate_head_align() to shrink the head alignment.
This results in always placing the small resource(s) after the big
resource.

In general, it would be good to be able to place the small resource(s)
before the big resource to achieve better utilization of the address space.
In the cases where the large resource can only fit at the end of the
window, it is even required.

However, carrying the information over from pbus_size_mem() and
calculate_head_align() to __pci_assign_resource() and
pcibios_align_resource() is not easy with the current data structures.

A somewhat hacky way to move the non-aligning tail part to the head is
possible within pcibios_align_resource(). The free space between the start
of the free space span and the aligned start address can be compared with
the non-aligning remainder of the size. If the free space is larger than
the remainder, placing the remainder before the start address is possible.
This relocation should generally work, because PCI resources consist only
power-of-2 atoms.

Various arch requirements may still need to override the relocation, so the
relocation is only applied selectively in such cases.

Closes: https://bugzilla.kernel.org/show_bug.cgi?id=221205
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Xifer <xiferdev@gmail.com>
Link: https://patch.msgid.link/20260324165633.4583-10-ilpo.jarvinen@linux.intel.com
---
 arch/arm/kernel/bios32.c         |  3 +++
 arch/m68k/kernel/pcibios.c       |  4 ++++
 arch/mips/pci/pci-generic.c      |  3 +++
 arch/mips/pci/pci-legacy.c       |  2 ++
 arch/parisc/kernel/pci.c         |  3 +++
 arch/powerpc/kernel/pci-common.c |  2 ++
 arch/sh/drivers/pci/pci.c        |  2 ++
 arch/x86/pci/i386.c              |  2 ++
 arch/xtensa/kernel/pci.c         |  2 ++
 drivers/pci/setup-res.c          | 39 ++++++++++++++++++++++++++++++++++++++-
 include/linux/pci.h              |  5 +++++
 kernel/resource.c                |  2 +-
 12 files changed, 67 insertions(+), 2 deletions(-)

(limited to 'include/linux')

diff --git a/arch/arm/kernel/bios32.c b/arch/arm/kernel/bios32.c
index cedb83a85dd9..ac0e890510da 100644
--- a/arch/arm/kernel/bios32.c
+++ b/arch/arm/kernel/bios32.c
@@ -577,6 +577,9 @@ resource_size_t pcibios_align_resource(void *data, const struct resource *res,
 		return host_bridge->align_resource(dev, res,
 				start, size, align);
 
+	if (res->flags & IORESOURCE_MEM)
+		return pci_align_resource(dev, res, empty_res, size, align);
+
 	return start;
 }
 
diff --git a/arch/m68k/kernel/pcibios.c b/arch/m68k/kernel/pcibios.c
index 7e286ee1976b..7a9e60df79c5 100644
--- a/arch/m68k/kernel/pcibios.c
+++ b/arch/m68k/kernel/pcibios.c
@@ -31,11 +31,15 @@ resource_size_t pcibios_align_resource(void *data, const struct resource *res,
 				       resource_size_t size,
 				       resource_size_t align)
 {
+	struct pci_dev *dev = data;
 	resource_size_t start = res->start;
 
 	if ((res->flags & IORESOURCE_IO) && (start & 0x300))
 		start = (start + 0x3ff) & ~0x3ff;
 
+	if (res->flags & IORESOURCE_MEM)
+		return pci_align_resource(dev, res, empty_res, size, align);
+
 	return start;
 }
 
diff --git a/arch/mips/pci/pci-generic.c b/arch/mips/pci/pci-generic.c
index aaa1d6de8bef..c2e23d0c1d77 100644
--- a/arch/mips/pci/pci-generic.c
+++ b/arch/mips/pci/pci-generic.c
@@ -38,6 +38,9 @@ resource_size_t pcibios_align_resource(void *data, const struct resource *res,
 		return host_bridge->align_resource(dev, res,
 				start, size, align);
 
+	if (res->flags & IORESOURCE_MEM)
+		return pci_align_resource(dev, res, empty_res, size, align);
+
 	return start;
 }
 
diff --git a/arch/mips/pci/pci-legacy.c b/arch/mips/pci/pci-legacy.c
index 817e97402afe..dae6dafdd6e0 100644
--- a/arch/mips/pci/pci-legacy.c
+++ b/arch/mips/pci/pci-legacy.c
@@ -70,6 +70,8 @@ pcibios_align_resource(void *data, const struct resource *res,
 		if (start & 0x300)
 			start = (start + 0x3ff) & ~0x3ff;
 	} else if (res->flags & IORESOURCE_MEM) {
+		start = pci_align_resource(dev, res, empty_res, size, align);
+
 		/* Make sure we start at our min on all hoses */
 		if (start < PCIBIOS_MIN_MEM + hose->mem_resource->start)
 			start = PCIBIOS_MIN_MEM + hose->mem_resource->start;
diff --git a/arch/parisc/kernel/pci.c b/arch/parisc/kernel/pci.c
index f50be1a63c4c..b8007c7400d4 100644
--- a/arch/parisc/kernel/pci.c
+++ b/arch/parisc/kernel/pci.c
@@ -201,6 +201,7 @@ resource_size_t pcibios_align_resource(void *data, const struct resource *res,
 				       resource_size_t size,
 				       resource_size_t alignment)
 {
+	struct pci_dev *dev = data;
 	resource_size_t align, start = res->start;
 
 	DBG_RES("pcibios_align_resource(%s, (%p) [%lx,%lx]/%x, 0x%lx, 0x%lx)\n",
@@ -212,6 +213,8 @@ resource_size_t pcibios_align_resource(void *data, const struct resource *res,
 	align = (res->flags & IORESOURCE_IO) ? PCIBIOS_MIN_IO : PCIBIOS_MIN_MEM;
 	if (align > alignment)
 		start = ALIGN(start, align);
+	else
+		start = pci_align_resource(dev, res, empty_res, size, alignment);
 
 	return start;
 }
diff --git a/arch/powerpc/kernel/pci-common.c b/arch/powerpc/kernel/pci-common.c
index e7bfa15da043..8efe95a0c4ff 100644
--- a/arch/powerpc/kernel/pci-common.c
+++ b/arch/powerpc/kernel/pci-common.c
@@ -1144,6 +1144,8 @@ resource_size_t pcibios_align_resource(void *data, const struct resource *res,
 			return start;
 		if (start & 0x300)
 			start = (start + 0x3ff) & ~0x3ff;
+	} else if (res->flags & IORESOURCE_MEM) {
+		start = pci_align_resource(dev, res, empty_res, size, align);
 	}
 
 	return start;
diff --git a/arch/sh/drivers/pci/pci.c b/arch/sh/drivers/pci/pci.c
index 7a0522316ee3..878a27a1acfb 100644
--- a/arch/sh/drivers/pci/pci.c
+++ b/arch/sh/drivers/pci/pci.c
@@ -185,6 +185,8 @@ resource_size_t pcibios_align_resource(void *data, const struct resource *res,
 		 */
 		if (start & 0x300)
 			start = (start + 0x3ff) & ~0x3ff;
+	} else if (res->flags & IORESOURCE_MEM) {
+		start = pci_align_resource(dev, res, empty_res, size, align);
 	}
 
 	return start;
diff --git a/arch/x86/pci/i386.c b/arch/x86/pci/i386.c
index 6fbd4b34c3f7..e2de26b82940 100644
--- a/arch/x86/pci/i386.c
+++ b/arch/x86/pci/i386.c
@@ -165,6 +165,8 @@ pcibios_align_resource(void *data, const struct resource *res,
 		if (start & 0x300)
 			start = (start + 0x3ff) & ~0x3ff;
 	} else if (res->flags & IORESOURCE_MEM) {
+		start = pci_align_resource(dev, res, empty_res, size, align);
+
 		/* The low 1MB range is reserved for ISA cards */
 		if (start < BIOS_END)
 			start = BIOS_END;
diff --git a/arch/xtensa/kernel/pci.c b/arch/xtensa/kernel/pci.c
index 64ccb7e0d92f..305031551136 100644
--- a/arch/xtensa/kernel/pci.c
+++ b/arch/xtensa/kernel/pci.c
@@ -54,6 +54,8 @@ pcibios_align_resource(void *data, const struct resource *res,
 
 		if (start & 0x300)
 			start = (start + 0x3ff) & ~0x3ff;
+	} else if (res->flags & IORESOURCE_MEM) {
+		start = pci_align_resource(dev, res, empty_res, size, align);
 	}
 
 	return start;
diff --git a/drivers/pci/setup-res.c b/drivers/pci/setup-res.c
index c375e255c509..fbc05cda96ee 100644
--- a/drivers/pci/setup-res.c
+++ b/drivers/pci/setup-res.c
@@ -244,6 +244,41 @@ static int pci_revert_fw_address(struct resource *res, struct pci_dev *dev,
 	return 0;
 }
 
+/*
+ * 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
@@ -255,7 +290,9 @@ resource_size_t __weak pcibios_align_resource(void *data,
 					      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,
diff --git a/include/linux/pci.h b/include/linux/pci.h
index ac332ff9da9f..cedf948dc614 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1210,6 +1210,11 @@ resource_size_t pcibios_align_resource(void *data, const struct resource *res,
 				       const struct resource *empty_res,
 				       resource_size_t size,
 				       resource_size_t align);
+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);
 
 /* Generic PCI functions used internally */
 
diff --git a/kernel/resource.c b/kernel/resource.c
index 8c5fcb30fc33..d02a53fb95d8 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -766,7 +766,7 @@ static int __find_resource_space(struct resource *root, struct resource *old,
 			}
 			alloc.end = alloc.start + size - 1;
 			if (alloc.start <= alloc.end &&
-			    __resource_contains_unbound(&avail, &alloc)) {
+			    __resource_contains_unbound(&full_avail, &alloc)) {
 				new->start = alloc.start;
 				new->end = alloc.end;
 				return 0;
-- 
cgit v1.2.3