[PATCH v7 2/4] resource: Use list_head to link sibling resource

From: Baoquan He
Date: Tue Jul 17 2018 - 22:52:44 EST

The struct resource uses singly linked list to link siblings, implemented
by pointer operation. Replace it with list_head for better code readability.

Based on this list_head replacement, it will be very easy to do reverse
iteration on iomem_resource's sibling list in later patch.

Besides, type of member variables of struct resource, sibling and child, are
changed from 'struct resource *' to 'struct list_head'. This brings two
pointers of size increase.

Suggested-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Baoquan He <bhe@xxxxxxxxxx>
Cc: Patrik Jakobsson <patrik.r.jakobsson@xxxxxxxxx>
Cc: David Airlie <airlied@xxxxxxxx>
Cc: "K. Y. Srinivasan" <kys@xxxxxxxxxxxxx>
Cc: Haiyang Zhang <haiyangz@xxxxxxxxxxxxx>
Cc: Stephen Hemminger <sthemmin@xxxxxxxxxxxxx>
Cc: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
Cc: Rob Herring <robh+dt@xxxxxxxxxx>
Cc: Frank Rowand <frowand.list@xxxxxxxxx>
Cc: Keith Busch <keith.busch@xxxxxxxxx>
Cc: Jonathan Derrick <jonathan.derrick@xxxxxxxxx>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Brijesh Singh <brijesh.singh@xxxxxxx>
Cc: "JÃrÃme Glisse" <jglisse@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxx>
Cc: Tom Lendacky <thomas.lendacky@xxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Yaowei Bai <baiyaowei@xxxxxxxxxxxxxxxxxxxx>
Cc: Wei Yang <richard.weiyang@xxxxxxxxx>
Cc: devel@xxxxxxxxxxxxxxxxxxxxxx
Cc: linux-input@xxxxxxxxxxxxxxx
Cc: linux-nvdimm@xxxxxxxxxxxx
Cc: devicetree@xxxxxxxxxxxxxxx
Cc: linux-pci@xxxxxxxxxxxxxxx
Cc: Michal Simek <monstr@xxxxxxxxx>
Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Cc: linux-mips@xxxxxxxxxxxxxx
---
arch/arm/plat-samsung/pm-check.c | 6 +-
arch/ia64/sn/kernel/io_init.c | 2 +-
arch/microblaze/pci/pci-common.c | 4 +-
arch/mips/pci/pci-rc32434.c | 12 +-
arch/powerpc/kernel/pci-common.c | 4 +-
arch/sparc/kernel/ioport.c | 2 +-
arch/xtensa/include/asm/pci-bridge.h | 4 +-
drivers/eisa/eisa-bus.c | 2 +
drivers/gpu/drm/drm_memory.c | 3 +-
drivers/gpu/drm/gma500/gtt.c | 5 +-
drivers/hv/vmbus_drv.c | 52 +++----
drivers/input/joystick/iforce/iforce-main.c | 4 +-
drivers/nvdimm/namespace_devs.c | 6 +-
drivers/nvdimm/nd.h | 5 +-
drivers/of/address.c | 4 +-
drivers/parisc/lba_pci.c | 4 +-
drivers/pci/controller/vmd.c | 8 +-
drivers/pci/probe.c | 2 +
drivers/pci/setup-bus.c | 2 +-
include/linux/ioport.h | 17 ++-
kernel/resource.c | 206 ++++++++++++++--------------
21 files changed, 183 insertions(+), 171 deletions(-)

diff --git a/arch/arm/plat-samsung/pm-check.c b/arch/arm/plat-samsung/pm-check.c
index cd2c02c68bc3..5494355b1c49 100644
--- a/arch/arm/plat-samsung/pm-check.c
+++ b/arch/arm/plat-samsung/pm-check.c
@@ -46,8 +46,8 @@ typedef u32 *(run_fn_t)(struct resource *ptr, u32 *arg);
static void s3c_pm_run_res(struct resource *ptr, run_fn_t fn, u32 *arg)
{
while (ptr != NULL) {
- if (ptr->child != NULL)
- s3c_pm_run_res(ptr->child, fn, arg);
+ if (!list_empty(&ptr->child))
+ s3c_pm_run_res(resource_first_child(&ptr->child), fn, arg);

if ((ptr->flags & IORESOURCE_SYSTEM_RAM)
== IORESOURCE_SYSTEM_RAM) {
@@ -57,7 +57,7 @@ static void s3c_pm_run_res(struct resource *ptr, run_fn_t fn, u32 *arg)
arg = (fn)(ptr, arg);
}

- ptr = ptr->sibling;
+ ptr = resource_sibling(ptr);
}
}

diff --git a/arch/ia64/sn/kernel/io_init.c b/arch/ia64/sn/kernel/io_init.c
index d63809a6adfa..338a7b7f194d 100644
--- a/arch/ia64/sn/kernel/io_init.c
+++ b/arch/ia64/sn/kernel/io_init.c
@@ -192,7 +192,7 @@ sn_io_slot_fixup(struct pci_dev *dev)
* if it's already in the device structure, remove it before
* inserting
*/
- if (res->parent && res->parent->child)
+ if (res->parent && !list_empty(&res->parent->child))
release_resource(res);

if (res->flags & IORESOURCE_IO)
diff --git a/arch/microblaze/pci/pci-common.c b/arch/microblaze/pci/pci-common.c
index 7899bafab064..2bf73e27e231 100644
--- a/arch/microblaze/pci/pci-common.c
+++ b/arch/microblaze/pci/pci-common.c
@@ -533,7 +533,9 @@ void pci_process_bridge_OF_ranges(struct pci_controller *hose,
res->flags = range.flags;
res->start = range.cpu_addr;
res->end = range.cpu_addr + range.size - 1;
- res->parent = res->child = res->sibling = NULL;
+ res->parent = NULL;
+ INIT_LIST_HEAD(&res->child);
+ INIT_LIST_HEAD(&res->sibling);
}
}

diff --git a/arch/mips/pci/pci-rc32434.c b/arch/mips/pci/pci-rc32434.c
index 7f6ce6d734c0..e80283df7925 100644
--- a/arch/mips/pci/pci-rc32434.c
+++ b/arch/mips/pci/pci-rc32434.c
@@ -53,8 +53,8 @@ static struct resource rc32434_res_pci_mem1 = {
.start = 0x50000000,
.end = 0x5FFFFFFF,
.flags = IORESOURCE_MEM,
- .sibling = NULL,
- .child = &rc32434_res_pci_mem2
+ .sibling = LIST_HEAD_INIT(rc32434_res_pci_mem1.sibling),
+ .child = LIST_HEAD_INIT(rc32434_res_pci_mem1.child),
};

static struct resource rc32434_res_pci_mem2 = {
@@ -63,8 +63,8 @@ static struct resource rc32434_res_pci_mem2 = {
.end = 0x6FFFFFFF,
.flags = IORESOURCE_MEM,
.parent = &rc32434_res_pci_mem1,
- .sibling = NULL,
- .child = NULL
+ .sibling = LIST_HEAD_INIT(rc32434_res_pci_mem2.sibling),
+ .child = LIST_HEAD_INIT(rc32434_res_pci_mem2.child),
};

static struct resource rc32434_res_pci_io1 = {
@@ -72,6 +72,8 @@ static struct resource rc32434_res_pci_io1 = {
.start = 0x18800000,
.end = 0x188FFFFF,
.flags = IORESOURCE_IO,
+ .sibling = LIST_HEAD_INIT(rc32434_res_pci_io1.sibling),
+ .child = LIST_HEAD_INIT(rc32434_res_pci_io1.child),
};

extern struct pci_ops rc32434_pci_ops;
@@ -208,6 +210,8 @@ static int __init rc32434_pci_init(void)

pr_info("PCI: Initializing PCI\n");

+ list_add(&rc32434_res_pci_mem2.sibling, &rc32434_res_pci_mem1.child);
+
ioport_resource.start = rc32434_res_pci_io1.start;
ioport_resource.end = rc32434_res_pci_io1.end;

diff --git a/arch/powerpc/kernel/pci-common.c b/arch/powerpc/kernel/pci-common.c
index 926035bb378d..28fbe83c9daf 100644
--- a/arch/powerpc/kernel/pci-common.c
+++ b/arch/powerpc/kernel/pci-common.c
@@ -761,7 +761,9 @@ void pci_process_bridge_OF_ranges(struct pci_controller *hose,
res->flags = range.flags;
res->start = range.cpu_addr;
res->end = range.cpu_addr + range.size - 1;
- res->parent = res->child = res->sibling = NULL;
+ res->parent = NULL;
+ INIT_LIST_HEAD(&res->child);
+ INIT_LIST_HEAD(&res->sibling);
}
}
}
diff --git a/arch/sparc/kernel/ioport.c b/arch/sparc/kernel/ioport.c
index cca9134cfa7d..99efe4e98b16 100644
--- a/arch/sparc/kernel/ioport.c
+++ b/arch/sparc/kernel/ioport.c
@@ -669,7 +669,7 @@ static int sparc_io_proc_show(struct seq_file *m, void *v)
struct resource *root = m->private, *r;
const char *nm;

- for (r = root->child; r != NULL; r = r->sibling) {
+ list_for_each_entry(r, &root->child, sibling) {
if ((nm = r->name) == NULL) nm = "???";
seq_printf(m, "%016llx-%016llx: %s\n",
(unsigned long long)r->start,
diff --git a/arch/xtensa/include/asm/pci-bridge.h b/arch/xtensa/include/asm/pci-bridge.h
index 0b68c76ec1e6..f487b06817df 100644
--- a/arch/xtensa/include/asm/pci-bridge.h
+++ b/arch/xtensa/include/asm/pci-bridge.h
@@ -71,8 +71,8 @@ static inline void pcibios_init_resource(struct resource *res,
res->flags = flags;
res->name = name;
res->parent = NULL;
- res->sibling = NULL;
- res->child = NULL;
+ INIT_LIST_HEAD(&res->child);
+ INIT_LIST_HEAD(&res->sibling);
}


diff --git a/drivers/eisa/eisa-bus.c b/drivers/eisa/eisa-bus.c
index 1e8062f6dbfc..dba78f75fd06 100644
--- a/drivers/eisa/eisa-bus.c
+++ b/drivers/eisa/eisa-bus.c
@@ -408,6 +408,8 @@ static struct resource eisa_root_res = {
.start = 0,
.end = 0xffffffff,
.flags = IORESOURCE_IO,
+ .sibling = LIST_HEAD_INIT(eisa_root_res.sibling),
+ .child = LIST_HEAD_INIT(eisa_root_res.child),
};

static int eisa_bus_count;
diff --git a/drivers/gpu/drm/drm_memory.c b/drivers/gpu/drm/drm_memory.c
index d69e4fc1ee77..33baa7fa5e41 100644
--- a/drivers/gpu/drm/drm_memory.c
+++ b/drivers/gpu/drm/drm_memory.c
@@ -155,9 +155,8 @@ u64 drm_get_max_iomem(void)
struct resource *tmp;
resource_size_t max_iomem = 0;

- for (tmp = iomem_resource.child; tmp; tmp = tmp->sibling) {
+ list_for_each_entry(tmp, &iomem_resource.child, sibling)
max_iomem = max(max_iomem, tmp->end);
- }

return max_iomem;
}
diff --git a/drivers/gpu/drm/gma500/gtt.c b/drivers/gpu/drm/gma500/gtt.c
index 3949b0990916..addd3bc009af 100644
--- a/drivers/gpu/drm/gma500/gtt.c
+++ b/drivers/gpu/drm/gma500/gtt.c
@@ -565,7 +565,7 @@ int psb_gtt_init(struct drm_device *dev, int resume)
int psb_gtt_restore(struct drm_device *dev)
{
struct drm_psb_private *dev_priv = dev->dev_private;
- struct resource *r = dev_priv->gtt_mem->child;
+ struct resource *r;
struct gtt_range *range;
unsigned int restored = 0, total = 0, size = 0;

@@ -573,14 +573,13 @@ int psb_gtt_restore(struct drm_device *dev)
mutex_lock(&dev_priv->gtt_mutex);
psb_gtt_init(dev, 1);

- while (r != NULL) {
+ list_for_each_entry(r, &dev_priv->gtt_mem->child, sibling) {
range = container_of(r, struct gtt_range, resource);
if (range->pages) {
psb_gtt_insert(dev, range, 1);
size += range->resource.end - range->resource.start;
restored++;
}
- r = r->sibling;
total++;
}
mutex_unlock(&dev_priv->gtt_mutex);
diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
index b10fe26c4891..d87ec5a1bc4c 100644
--- a/drivers/hv/vmbus_drv.c
+++ b/drivers/hv/vmbus_drv.c
@@ -1412,9 +1412,8 @@ static acpi_status vmbus_walk_resources(struct acpi_resource *res, void *ctx)
{
resource_size_t start = 0;
resource_size_t end = 0;
- struct resource *new_res;
+ struct resource *new_res, *tmp;
struct resource **old_res = &hyperv_mmio;
- struct resource **prev_res = NULL;

switch (res->type) {

@@ -1461,44 +1460,36 @@ static acpi_status vmbus_walk_resources(struct acpi_resource *res, void *ctx)
/*
* If two ranges are adjacent, merge them.
*/
- do {
- if (!*old_res) {
- *old_res = new_res;
- break;
- }
-
- if (((*old_res)->end + 1) == new_res->start) {
- (*old_res)->end = new_res->end;
+ if (!*old_res) {
+ *old_res = new_res;
+ return AE_OK;
+ }
+ tmp = *old_res;
+ list_for_each_entry_from(tmp, &tmp->parent->child, sibling) {
+ if ((tmp->end + 1) == new_res->start) {
+ tmp->end = new_res->end;
kfree(new_res);
break;
}

- if ((*old_res)->start == new_res->end + 1) {
- (*old_res)->start = new_res->start;
+ if (tmp->start == new_res->end + 1) {
+ tmp->start = new_res->start;
kfree(new_res);
break;
}

- if ((*old_res)->start > new_res->end) {
- new_res->sibling = *old_res;
- if (prev_res)
- (*prev_res)->sibling = new_res;
- *old_res = new_res;
+ if (tmp->start > new_res->end) {
+ list_add(&new_res->sibling, tmp->sibling.prev);
break;
}
-
- prev_res = old_res;
- old_res = &(*old_res)->sibling;
-
- } while (1);
+ }

return AE_OK;
}

static int vmbus_acpi_remove(struct acpi_device *device)
{
- struct resource *cur_res;
- struct resource *next_res;
+ struct resource *res;

if (hyperv_mmio) {
if (fb_mmio) {
@@ -1507,10 +1498,9 @@ static int vmbus_acpi_remove(struct acpi_device *device)
fb_mmio = NULL;
}

- for (cur_res = hyperv_mmio; cur_res; cur_res = next_res) {
- next_res = cur_res->sibling;
- kfree(cur_res);
- }
+ res = hyperv_mmio;
+ list_for_each_entry_from(res, &res->parent->child, sibling)
+ kfree(res);
}

return 0;
@@ -1596,7 +1586,8 @@ int vmbus_allocate_mmio(struct resource **new, struct hv_device *device_obj,
}
}

- for (iter = hyperv_mmio; iter; iter = iter->sibling) {
+ iter = hyperv_mmio;
+ list_for_each_entry_from(iter, &iter->parent->child, sibling) {
if ((iter->start >= max) || (iter->end <= min))
continue;

@@ -1639,7 +1630,8 @@ void vmbus_free_mmio(resource_size_t start, resource_size_t size)
struct resource *iter;

down(&hyperv_mmio_lock);
- for (iter = hyperv_mmio; iter; iter = iter->sibling) {
+ iter = hyperv_mmio;
+ list_for_each_entry_from(iter, &iter->parent->child, sibling) {
if ((iter->start >= start + size) || (iter->end <= start))
continue;

diff --git a/drivers/input/joystick/iforce/iforce-main.c b/drivers/input/joystick/iforce/iforce-main.c
index daeeb4c7e3b0..5c0be27b33ff 100644
--- a/drivers/input/joystick/iforce/iforce-main.c
+++ b/drivers/input/joystick/iforce/iforce-main.c
@@ -305,8 +305,8 @@ int iforce_init_device(struct iforce *iforce)
iforce->device_memory.end = 200;
iforce->device_memory.flags = IORESOURCE_MEM;
iforce->device_memory.parent = NULL;
- iforce->device_memory.child = NULL;
- iforce->device_memory.sibling = NULL;
+ INIT_LIST_HEAD(&iforce->device_memory.child);
+ INIT_LIST_HEAD(&iforce->device_memory.sibling);

/*
* Wait until device ready - until it sends its first response.
diff --git a/drivers/nvdimm/namespace_devs.c b/drivers/nvdimm/namespace_devs.c
index 28afdd668905..f53d410d9981 100644
--- a/drivers/nvdimm/namespace_devs.c
+++ b/drivers/nvdimm/namespace_devs.c
@@ -637,7 +637,7 @@ static resource_size_t scan_allocate(struct nd_region *nd_region,
retry:
first = 0;
for_each_dpa_resource(ndd, res) {
- struct resource *next = res->sibling, *new_res = NULL;
+ struct resource *next = resource_sibling(res), *new_res = NULL;
resource_size_t allocate, available = 0;
enum alloc_loc loc = ALLOC_ERR;
const char *action;
@@ -763,7 +763,7 @@ static resource_size_t scan_allocate(struct nd_region *nd_region,
* an initial "pmem-reserve pass". Only do an initial BLK allocation
* when none of the DPA space is reserved.
*/
- if ((is_pmem || !ndd->dpa.child) && n == to_allocate)
+ if ((is_pmem || list_empty(&ndd->dpa.child)) && n == to_allocate)
return init_dpa_allocation(label_id, nd_region, nd_mapping, n);
return n;
}
@@ -779,7 +779,7 @@ static int merge_dpa(struct nd_region *nd_region,
retry:
for_each_dpa_resource(ndd, res) {
int rc;
- struct resource *next = res->sibling;
+ struct resource *next = resource_sibling(res);
resource_size_t end = res->start + resource_size(res);

if (!next || strcmp(res->name, label_id->id) != 0
diff --git a/drivers/nvdimm/nd.h b/drivers/nvdimm/nd.h
index 32e0364b48b9..da7da15e03e7 100644
--- a/drivers/nvdimm/nd.h
+++ b/drivers/nvdimm/nd.h
@@ -102,11 +102,10 @@ unsigned sizeof_namespace_label(struct nvdimm_drvdata *ndd);
(unsigned long long) (res ? res->start : 0), ##arg)

#define for_each_dpa_resource(ndd, res) \
- for (res = (ndd)->dpa.child; res; res = res->sibling)
+ list_for_each_entry(res, &(ndd)->dpa.child, sibling)

#define for_each_dpa_resource_safe(ndd, res, next) \
- for (res = (ndd)->dpa.child, next = res ? res->sibling : NULL; \
- res; res = next, next = next ? next->sibling : NULL)
+ list_for_each_entry_safe(res, next, &(ndd)->dpa.child, sibling)

struct nd_percpu_lane {
int count;
diff --git a/drivers/of/address.c b/drivers/of/address.c
index 53349912ac75..e2e25719ab52 100644
--- a/drivers/of/address.c
+++ b/drivers/of/address.c
@@ -330,7 +330,9 @@ int of_pci_range_to_resource(struct of_pci_range *range,
{
int err;
res->flags = range->flags;
- res->parent = res->child = res->sibling = NULL;
+ res->parent = NULL;
+ INIT_LIST_HEAD(&res->child);
+ INIT_LIST_HEAD(&res->sibling);
res->name = np->full_name;

if (res->flags & IORESOURCE_IO) {
diff --git a/drivers/parisc/lba_pci.c b/drivers/parisc/lba_pci.c
index 69bd98421eb1..7482bdfd1959 100644
--- a/drivers/parisc/lba_pci.c
+++ b/drivers/parisc/lba_pci.c
@@ -170,8 +170,8 @@ lba_dump_res(struct resource *r, int d)
for (i = d; i ; --i) printk(" ");
printk(KERN_DEBUG "%p [%lx,%lx]/%lx\n", r,
(long)r->start, (long)r->end, r->flags);
- lba_dump_res(r->child, d+2);
- lba_dump_res(r->sibling, d);
+ lba_dump_res(resource_first_child(&r->child), d+2);
+ lba_dump_res(resource_sibling(r), d);
}


diff --git a/drivers/pci/controller/vmd.c b/drivers/pci/controller/vmd.c
index 942b64fc7f1f..e3ace20345c7 100644
--- a/drivers/pci/controller/vmd.c
+++ b/drivers/pci/controller/vmd.c
@@ -542,14 +542,14 @@ static struct pci_ops vmd_ops = {

static void vmd_attach_resources(struct vmd_dev *vmd)
{
- vmd->dev->resource[VMD_MEMBAR1].child = &vmd->resources[1];
- vmd->dev->resource[VMD_MEMBAR2].child = &vmd->resources[2];
+ list_add(&vmd->resources[1].sibling, &vmd->dev->resource[VMD_MEMBAR1].child);
+ list_add(&vmd->resources[2].sibling, &vmd->dev->resource[VMD_MEMBAR2].child);
}

static void vmd_detach_resources(struct vmd_dev *vmd)
{
- vmd->dev->resource[VMD_MEMBAR1].child = NULL;
- vmd->dev->resource[VMD_MEMBAR2].child = NULL;
+ INIT_LIST_HEAD(&vmd->dev->resource[VMD_MEMBAR1].child);
+ INIT_LIST_HEAD(&vmd->dev->resource[VMD_MEMBAR2].child);
}

/*
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index ac876e32de4b..9624dd1dfd49 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -59,6 +59,8 @@ static struct resource *get_pci_domain_busn_res(int domain_nr)
r->res.start = 0;
r->res.end = 0xff;
r->res.flags = IORESOURCE_BUS | IORESOURCE_PCI_FIXED;
+ INIT_LIST_HEAD(&r->res.child);
+ INIT_LIST_HEAD(&r->res.sibling);

list_add_tail(&r->list, &pci_domain_busn_res_list);

diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index 79b1824e83b4..8e685af8938d 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -2107,7 +2107,7 @@ int pci_reassign_bridge_resources(struct pci_dev *bridge, unsigned long type)
continue;

/* Ignore BARs which are still in use */
- if (res->child)
+ if (!list_empty(&res->child))
continue;

ret = add_to_list(&saved, bridge, res, 0, 0);
diff --git a/include/linux/ioport.h b/include/linux/ioport.h
index dfdcd0bfe54e..b7456ae889dd 100644
--- a/include/linux/ioport.h
+++ b/include/linux/ioport.h
@@ -12,6 +12,7 @@
#ifndef __ASSEMBLY__
#include <linux/compiler.h>
#include <linux/types.h>
+#include <linux/list.h>
/*
* Resources are tree-like, allowing
* nesting etc..
@@ -22,7 +23,8 @@ struct resource {
const char *name;
unsigned long flags;
unsigned long desc;
- struct resource *parent, *sibling, *child;
+ struct list_head child, sibling;
+ struct resource *parent;
};

/*
@@ -216,7 +218,6 @@ static inline bool resource_contains(struct resource *r1, struct resource *r2)
return r1->start <= r2->start && r1->end >= r2->end;
}

-
/* Convenience shorthand with allocation */
#define request_region(start,n,name) __request_region(&ioport_resource, (start), (n), (name), 0)
#define request_muxed_region(start,n,name) __request_region(&ioport_resource, (start), (n), (name), IORESOURCE_MUXED)
@@ -287,6 +288,18 @@ static inline bool resource_overlaps(struct resource *r1, struct resource *r2)
return (r1->start <= r2->end && r1->end >= r2->start);
}

+static inline struct resource *resource_sibling(struct resource *res)
+{
+ if (res->parent && !list_is_last(&res->sibling, &res->parent->child))
+ return list_next_entry(res, sibling);
+ return NULL;
+}
+
+static inline struct resource *resource_first_child(struct list_head *head)
+{
+ return list_first_entry_or_null(head, struct resource, sibling);
+}
+

#endif /* __ASSEMBLY__ */
#endif /* _LINUX_IOPORT_H */
diff --git a/kernel/resource.c b/kernel/resource.c
index 81ccd19c1d9f..c96e58d3d2f8 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -31,6 +31,8 @@ struct resource ioport_resource = {
.start = 0,
.end = IO_SPACE_LIMIT,
.flags = IORESOURCE_IO,
+ .sibling = LIST_HEAD_INIT(ioport_resource.sibling),
+ .child = LIST_HEAD_INIT(ioport_resource.child),
};
EXPORT_SYMBOL(ioport_resource);

@@ -39,6 +41,8 @@ struct resource iomem_resource = {
.start = 0,
.end = -1,
.flags = IORESOURCE_MEM,
+ .sibling = LIST_HEAD_INIT(iomem_resource.sibling),
+ .child = LIST_HEAD_INIT(iomem_resource.child),
};
EXPORT_SYMBOL(iomem_resource);

@@ -57,20 +61,20 @@ static DEFINE_RWLOCK(resource_lock);
* by boot mem after the system is up. So for reusing the resource entry
* we need to remember the resource.
*/
-static struct resource *bootmem_resource_free;
+static struct list_head bootmem_resource_free = LIST_HEAD_INIT(bootmem_resource_free);
static DEFINE_SPINLOCK(bootmem_resource_lock);

static struct resource *next_resource(struct resource *p, bool sibling_only)
{
/* Caller wants to traverse through siblings only */
if (sibling_only)
- return p->sibling;
+ return resource_sibling(p);

- if (p->child)
- return p->child;
- while (!p->sibling && p->parent)
+ if (!list_empty(&p->child))
+ return resource_first_child(&p->child);
+ while (!resource_sibling(p) && p->parent)
p = p->parent;
- return p->sibling;
+ return resource_sibling(p);
}

static void *r_next(struct seq_file *m, void *v, loff_t *pos)
@@ -90,7 +94,7 @@ static void *r_start(struct seq_file *m, loff_t *pos)
struct resource *p = PDE_DATA(file_inode(m->file));
loff_t l = 0;
read_lock(&resource_lock);
- for (p = p->child; p && l < *pos; p = r_next(m, p, &l))
+ for (p = resource_first_child(&p->child); p && l < *pos; p = r_next(m, p, &l))
;
return p;
}
@@ -153,8 +157,7 @@ static void free_resource(struct resource *res)

if (!PageSlab(virt_to_head_page(res))) {
spin_lock(&bootmem_resource_lock);
- res->sibling = bootmem_resource_free;
- bootmem_resource_free = res;
+ list_add(&res->sibling, &bootmem_resource_free);
spin_unlock(&bootmem_resource_lock);
} else {
kfree(res);
@@ -166,10 +169,9 @@ static struct resource *alloc_resource(gfp_t flags)
struct resource *res = NULL;

spin_lock(&bootmem_resource_lock);
- if (bootmem_resource_free) {
- res = bootmem_resource_free;
- bootmem_resource_free = res->sibling;
- }
+ res = resource_first_child(&bootmem_resource_free);
+ if (res)
+ list_del(&res->sibling);
spin_unlock(&bootmem_resource_lock);

if (res)
@@ -177,6 +179,8 @@ static struct resource *alloc_resource(gfp_t flags)
else
res = kzalloc(sizeof(struct resource), flags);

+ INIT_LIST_HEAD(&res->child);
+ INIT_LIST_HEAD(&res->sibling);
return res;
}

@@ -185,7 +189,7 @@ static struct resource * __request_resource(struct resource *root, struct resour
{
resource_size_t start = new->start;
resource_size_t end = new->end;
- struct resource *tmp, **p;
+ struct resource *tmp;

if (end < start)
return root;
@@ -193,64 +197,62 @@ static struct resource * __request_resource(struct resource *root, struct resour
return root;
if (end > root->end)
return root;
- p = &root->child;
- for (;;) {
- tmp = *p;
- if (!tmp || tmp->start > end) {
- new->sibling = tmp;
- *p = new;
+
+ if (list_empty(&root->child)) {
+ list_add(&new->sibling, &root->child);
+ new->parent = root;
+ INIT_LIST_HEAD(&new->child);
+ return NULL;
+ }
+
+ list_for_each_entry(tmp, &root->child, sibling) {
+ if (tmp->start > end) {
+ list_add(&new->sibling, tmp->sibling.prev);
new->parent = root;
+ INIT_LIST_HEAD(&new->child);
return NULL;
}
- p = &tmp->sibling;
if (tmp->end < start)
continue;
return tmp;
}
+
+ list_add_tail(&new->sibling, &root->child);
+ new->parent = root;
+ INIT_LIST_HEAD(&new->child);
+ return NULL;
}

static int __release_resource(struct resource *old, bool release_child)
{
- struct resource *tmp, **p, *chd;
+ struct resource *tmp, *next, *chd;

- p = &old->parent->child;
- for (;;) {
- tmp = *p;
- if (!tmp)
- break;
+ list_for_each_entry_safe(tmp, next, &old->parent->child, sibling) {
if (tmp == old) {
- if (release_child || !(tmp->child)) {
- *p = tmp->sibling;
+ if (release_child || list_empty(&tmp->child)) {
+ list_del(&tmp->sibling);
} else {
- for (chd = tmp->child;; chd = chd->sibling) {
+ list_for_each_entry(chd, &tmp->child, sibling)
chd->parent = tmp->parent;
- if (!(chd->sibling))
- break;
- }
- *p = tmp->child;
- chd->sibling = tmp->sibling;
+ list_splice(&tmp->child, tmp->sibling.prev);
+ list_del(&tmp->sibling);
}
+
old->parent = NULL;
return 0;
}
- p = &tmp->sibling;
}
return -EINVAL;
}

static void __release_child_resources(struct resource *r)
{
- struct resource *tmp, *p;
+ struct resource *tmp, *next;
resource_size_t size;

- p = r->child;
- r->child = NULL;
- while (p) {
- tmp = p;
- p = p->sibling;
-
+ list_for_each_entry_safe(tmp, next, &r->child, sibling) {
tmp->parent = NULL;
- tmp->sibling = NULL;
+ list_del_init(&tmp->sibling);
__release_child_resources(tmp);

printk(KERN_DEBUG "release child resource %pR\n", tmp);
@@ -259,6 +261,8 @@ static void __release_child_resources(struct resource *r)
tmp->start = 0;
tmp->end = size - 1;
}
+
+ INIT_LIST_HEAD(&tmp->child);
}

void release_child_resources(struct resource *r)
@@ -343,7 +347,8 @@ static int find_next_iomem_res(struct resource *res, unsigned long desc,

read_lock(&resource_lock);

- for (p = iomem_resource.child; p; p = next_resource(p, sibling_only)) {
+ for (p = resource_first_child(&iomem_resource.child); p;
+ p = next_resource(p, sibling_only)) {
if ((p->flags & res->flags) != res->flags)
continue;
if ((desc != IORES_DESC_NONE) && (desc != p->desc))
@@ -532,7 +537,7 @@ int region_intersects(resource_size_t start, size_t size, unsigned long flags,
struct resource *p;

read_lock(&resource_lock);
- for (p = iomem_resource.child; p ; p = p->sibling) {
+ list_for_each_entry(p, &iomem_resource.child, sibling) {
bool is_type = (((p->flags & flags) == flags) &&
((desc == IORES_DESC_NONE) ||
(desc == p->desc)));
@@ -586,7 +591,7 @@ static int __find_resource(struct resource *root, struct resource *old,
resource_size_t size,
struct resource_constraint *constraint)
{
- struct resource *this = root->child;
+ struct resource *this = resource_first_child(&root->child);
struct resource tmp = *new, avail, alloc;

tmp.start = root->start;
@@ -596,7 +601,7 @@ static int __find_resource(struct resource *root, struct resource *old,
*/
if (this && this->start == root->start) {
tmp.start = (this == old) ? old->start : this->end + 1;
- this = this->sibling;
+ this = resource_sibling(this);
}
for(;;) {
if (this)
@@ -632,7 +637,7 @@ next: if (!this || this->end == root->end)

if (this != old)
tmp.start = this->end + 1;
- this = this->sibling;
+ this = resource_sibling(this);
}
return -EBUSY;
}
@@ -676,7 +681,7 @@ static int reallocate_resource(struct resource *root, struct resource *old,
goto out;
}

- if (old->child) {
+ if (!list_empty(&old->child)) {
err = -EBUSY;
goto out;
}
@@ -757,7 +762,7 @@ struct resource *lookup_resource(struct resource *root, resource_size_t start)
struct resource *res;

read_lock(&resource_lock);
- for (res = root->child; res; res = res->sibling) {
+ list_for_each_entry(res, &root->child, sibling) {
if (res->start == start)
break;
}
@@ -790,32 +795,27 @@ static struct resource * __insert_resource(struct resource *parent, struct resou
break;
}

- for (next = first; ; next = next->sibling) {
+ for (next = first; ; next = resource_sibling(next)) {
/* Partial overlap? Bad, and unfixable */
if (next->start < new->start || next->end > new->end)
return next;
- if (!next->sibling)
+ if (!resource_sibling(next))
break;
- if (next->sibling->start > new->end)
+ if (resource_sibling(next)->start > new->end)
break;
}
-
new->parent = parent;
- new->sibling = next->sibling;
- new->child = first;
+ list_add(&new->sibling, &next->sibling);
+ INIT_LIST_HEAD(&new->child);

- next->sibling = NULL;
- for (next = first; next; next = next->sibling)
+ /*
+ * From first to next, they all fall into new's region, so change them
+ * as new's children.
+ */
+ list_cut_position(&new->child, first->sibling.prev, &next->sibling);
+ list_for_each_entry(next, &new->child, sibling)
next->parent = new;

- if (parent->child == first) {
- parent->child = new;
- } else {
- next = parent->child;
- while (next->sibling != first)
- next = next->sibling;
- next->sibling = new;
- }
return NULL;
}

@@ -937,19 +937,17 @@ static int __adjust_resource(struct resource *res, resource_size_t start,
if ((start < parent->start) || (end > parent->end))
goto out;

- if (res->sibling && (res->sibling->start <= end))
+ if (resource_sibling(res) && (resource_sibling(res)->start <= end))
goto out;

- tmp = parent->child;
- if (tmp != res) {
- while (tmp->sibling != res)
- tmp = tmp->sibling;
+ if (res->sibling.prev != &parent->child) {
+ tmp = list_prev_entry(res, sibling);
if (start <= tmp->end)
goto out;
}

skip:
- for (tmp = res->child; tmp; tmp = tmp->sibling)
+ list_for_each_entry(tmp, &res->child, sibling)
if ((tmp->start < start) || (tmp->end > end))
goto out;

@@ -996,27 +994,30 @@ EXPORT_SYMBOL(adjust_resource);
*/
int reparent_resources(struct resource *parent, struct resource *res)
{
- struct resource *p, **pp;
- struct resource **firstpp = NULL;
+ struct resource *p, *first = NULL;

- for (pp = &parent->child; (p = *pp) != NULL; pp = &p->sibling) {
+ list_for_each_entry(p, &parent->child, sibling) {
if (p->end < res->start)
continue;
if (res->end < p->start)
break;
if (p->start < res->start || p->end > res->end)
return -ENOTSUPP; /* not completely contained */
- if (firstpp == NULL)
- firstpp = pp;
+ if (first == NULL)
+ first = p;
}
- if (firstpp == NULL)
+ if (first == NULL)
return -ECANCELED; /* didn't find any conflicting entries? */
res->parent = parent;
- res->child = *firstpp;
- res->sibling = *pp;
- *firstpp = res;
- *pp = NULL;
- for (p = res->child; p != NULL; p = p->sibling) {
+ list_add(&res->sibling, p->sibling.prev);
+ INIT_LIST_HEAD(&res->child);
+
+ /*
+ * From first to p's previous sibling, they all fall into
+ * res's region, change them as res's children.
+ */
+ list_cut_position(&res->child, first->sibling.prev, res->sibling.prev);
+ list_for_each_entry(p, &res->child, sibling) {
p->parent = res;
pr_debug("PCI: Reparented %s %pR under %s\n",
p->name, p, res->name);
@@ -1216,34 +1217,32 @@ EXPORT_SYMBOL(__request_region);
void __release_region(struct resource *parent, resource_size_t start,
resource_size_t n)
{
- struct resource **p;
+ struct resource *res;
resource_size_t end;

- p = &parent->child;
+ res = resource_first_child(&parent->child);
end = start + n - 1;

write_lock(&resource_lock);

for (;;) {
- struct resource *res = *p;
-
if (!res)
break;
if (res->start <= start && res->end >= end) {
if (!(res->flags & IORESOURCE_BUSY)) {
- p = &res->child;
+ res = resource_first_child(&res->child);
continue;
}
if (res->start != start || res->end != end)
break;
- *p = res->sibling;
+ list_del(&res->sibling);
write_unlock(&resource_lock);
if (res->flags & IORESOURCE_MUXED)
wake_up(&muxed_resource_wait);
free_resource(res);
return;
}
- p = &res->sibling;
+ res = resource_sibling(res);
}

write_unlock(&resource_lock);
@@ -1278,9 +1277,7 @@ EXPORT_SYMBOL(__release_region);
int release_mem_region_adjustable(struct resource *parent,
resource_size_t start, resource_size_t size)
{
- struct resource **p;
- struct resource *res;
- struct resource *new_res;
+ struct resource *res, *new_res;
resource_size_t end;
int ret = -EINVAL;

@@ -1291,16 +1288,16 @@ int release_mem_region_adjustable(struct resource *parent,
/* The alloc_resource() result gets checked later */
new_res = alloc_resource(GFP_KERNEL);

- p = &parent->child;
+ res = resource_first_child(&parent->child);
write_lock(&resource_lock);

- while ((res = *p)) {
+ while ((res)) {
if (res->start >= end)
break;

/* look for the next resource if it does not fit into */
if (res->start > start || res->end < end) {
- p = &res->sibling;
+ res = resource_sibling(res);
continue;
}

@@ -1308,14 +1305,14 @@ int release_mem_region_adjustable(struct resource *parent,
break;

if (!(res->flags & IORESOURCE_BUSY)) {
- p = &res->child;
+ res = resource_first_child(&res->child);
continue;
}

/* found the target resource; let's adjust accordingly */
if (res->start == start && res->end == end) {
/* free the whole entry */
- *p = res->sibling;
+ list_del(&res->sibling);
free_resource(res);
ret = 0;
} else if (res->start == start && res->end != end) {
@@ -1338,14 +1335,13 @@ int release_mem_region_adjustable(struct resource *parent,
new_res->flags = res->flags;
new_res->desc = res->desc;
new_res->parent = res->parent;
- new_res->sibling = res->sibling;
- new_res->child = NULL;
+ INIT_LIST_HEAD(&new_res->child);

ret = __adjust_resource(res, res->start,
start - res->start);
if (ret)
break;
- res->sibling = new_res;
+ list_add(&new_res->sibling, &res->sibling);
new_res = NULL;
}

@@ -1526,7 +1522,7 @@ static int __init reserve_setup(char *str)
res->end = io_start + io_num - 1;
res->flags |= IORESOURCE_BUSY;
res->desc = IORES_DESC_NONE;
- res->child = NULL;
+ INIT_LIST_HEAD(&res->child);
if (request_resource(parent, res) == 0)
reserved = x+1;
}
@@ -1546,7 +1542,7 @@ int iomem_map_sanity_check(resource_size_t addr, unsigned long size)
loff_t l;

read_lock(&resource_lock);
- for (p = p->child; p ; p = r_next(NULL, p, &l)) {
+ for (p = resource_first_child(&p->child); p; p = r_next(NULL, p, &l)) {
/*
* We can probably skip the resources without
* IORESOURCE_IO attribute?
@@ -1602,7 +1598,7 @@ bool iomem_is_exclusive(u64 addr)
addr = addr & PAGE_MASK;

read_lock(&resource_lock);
- for (p = p->child; p ; p = r_next(NULL, p, &l)) {
+ for (p = resource_first_child(&p->child); p; p = r_next(NULL, p, &l)) {
/*
* We can probably skip the resources without
* IORESOURCE_IO attribute?
--
2.13.6