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-rw-r--r--lib/Kconfig13
-rw-r--r--lib/Makefile2
-rw-r--r--lib/cpu_rmap.c269
-rw-r--r--lib/debugobjects.c9
-rw-r--r--lib/dynamic_debug.c61
-rw-r--r--lib/nlattr.c2
-rw-r--r--lib/plist.c135
-rw-r--r--lib/rwsem.c10
-rw-r--r--lib/swiotlb.c6
9 files changed, 465 insertions, 42 deletions
diff --git a/lib/Kconfig b/lib/Kconfig
index 0ee67e0..3a55a43 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -201,6 +201,10 @@ config DISABLE_OBSOLETE_CPUMASK_FUNCTIONS
bool "Disable obsolete cpumask functions" if DEBUG_PER_CPU_MAPS
depends on EXPERIMENTAL && BROKEN
+config CPU_RMAP
+ bool
+ depends on SMP
+
#
# Netlink attribute parsing support is select'ed if needed
#
@@ -217,6 +221,13 @@ config LRU_CACHE
tristate
config AVERAGE
- bool
+ bool "Averaging functions"
+ help
+ This option is provided for the case where no in-kernel-tree
+ modules require averaging functions, but a module built outside
+ the kernel tree does. Such modules that use library averaging
+ functions require Y here.
+
+ If unsure, say N.
endmenu
diff --git a/lib/Makefile b/lib/Makefile
index de6c609..ef7ed71 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -109,6 +109,8 @@ obj-$(CONFIG_ATOMIC64_SELFTEST) += atomic64_test.o
obj-$(CONFIG_AVERAGE) += average.o
+obj-$(CONFIG_CPU_RMAP) += cpu_rmap.o
+
hostprogs-y := gen_crc32table
clean-files := crc32table.h
diff --git a/lib/cpu_rmap.c b/lib/cpu_rmap.c
new file mode 100644
index 0000000..987acfa
--- /dev/null
+++ b/lib/cpu_rmap.c
@@ -0,0 +1,269 @@
+/*
+ * cpu_rmap.c: CPU affinity reverse-map support
+ * Copyright 2011 Solarflare Communications Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published
+ * by the Free Software Foundation, incorporated herein by reference.
+ */
+
+#include <linux/cpu_rmap.h>
+#ifdef CONFIG_GENERIC_HARDIRQS
+#include <linux/interrupt.h>
+#endif
+#include <linux/module.h>
+
+/*
+ * These functions maintain a mapping from CPUs to some ordered set of
+ * objects with CPU affinities. This can be seen as a reverse-map of
+ * CPU affinity. However, we do not assume that the object affinities
+ * cover all CPUs in the system. For those CPUs not directly covered
+ * by object affinities, we attempt to find a nearest object based on
+ * CPU topology.
+ */
+
+/**
+ * alloc_cpu_rmap - allocate CPU affinity reverse-map
+ * @size: Number of objects to be mapped
+ * @flags: Allocation flags e.g. %GFP_KERNEL
+ */
+struct cpu_rmap *alloc_cpu_rmap(unsigned int size, gfp_t flags)
+{
+ struct cpu_rmap *rmap;
+ unsigned int cpu;
+ size_t obj_offset;
+
+ /* This is a silly number of objects, and we use u16 indices. */
+ if (size > 0xffff)
+ return NULL;
+
+ /* Offset of object pointer array from base structure */
+ obj_offset = ALIGN(offsetof(struct cpu_rmap, near[nr_cpu_ids]),
+ sizeof(void *));
+
+ rmap = kzalloc(obj_offset + size * sizeof(rmap->obj[0]), flags);
+ if (!rmap)
+ return NULL;
+
+ rmap->obj = (void **)((char *)rmap + obj_offset);
+
+ /* Initially assign CPUs to objects on a rota, since we have
+ * no idea where the objects are. Use infinite distance, so
+ * any object with known distance is preferable. Include the
+ * CPUs that are not present/online, since we definitely want
+ * any newly-hotplugged CPUs to have some object assigned.
+ */
+ for_each_possible_cpu(cpu) {
+ rmap->near[cpu].index = cpu % size;
+ rmap->near[cpu].dist = CPU_RMAP_DIST_INF;
+ }
+
+ rmap->size = size;
+ return rmap;
+}
+EXPORT_SYMBOL(alloc_cpu_rmap);
+
+/* Reevaluate nearest object for given CPU, comparing with the given
+ * neighbours at the given distance.
+ */
+static bool cpu_rmap_copy_neigh(struct cpu_rmap *rmap, unsigned int cpu,
+ const struct cpumask *mask, u16 dist)
+{
+ int neigh;
+
+ for_each_cpu(neigh, mask) {
+ if (rmap->near[cpu].dist > dist &&
+ rmap->near[neigh].dist <= dist) {
+ rmap->near[cpu].index = rmap->near[neigh].index;
+ rmap->near[cpu].dist = dist;
+ return true;
+ }
+ }
+ return false;
+}
+
+#ifdef DEBUG
+static void debug_print_rmap(const struct cpu_rmap *rmap, const char *prefix)
+{
+ unsigned index;
+ unsigned int cpu;
+
+ pr_info("cpu_rmap %p, %s:\n", rmap, prefix);
+
+ for_each_possible_cpu(cpu) {
+ index = rmap->near[cpu].index;
+ pr_info("cpu %d -> obj %u (distance %u)\n",
+ cpu, index, rmap->near[cpu].dist);
+ }
+}
+#else
+static inline void
+debug_print_rmap(const struct cpu_rmap *rmap, const char *prefix)
+{
+}
+#endif
+
+/**
+ * cpu_rmap_add - add object to a rmap
+ * @rmap: CPU rmap allocated with alloc_cpu_rmap()
+ * @obj: Object to add to rmap
+ *
+ * Return index of object.
+ */
+int cpu_rmap_add(struct cpu_rmap *rmap, void *obj)
+{
+ u16 index;
+
+ BUG_ON(rmap->used >= rmap->size);
+ index = rmap->used++;
+ rmap->obj[index] = obj;
+ return index;
+}
+EXPORT_SYMBOL(cpu_rmap_add);
+
+/**
+ * cpu_rmap_update - update CPU rmap following a change of object affinity
+ * @rmap: CPU rmap to update
+ * @index: Index of object whose affinity changed
+ * @affinity: New CPU affinity of object
+ */
+int cpu_rmap_update(struct cpu_rmap *rmap, u16 index,
+ const struct cpumask *affinity)
+{
+ cpumask_var_t update_mask;
+ unsigned int cpu;
+
+ if (unlikely(!zalloc_cpumask_var(&update_mask, GFP_KERNEL)))
+ return -ENOMEM;
+
+ /* Invalidate distance for all CPUs for which this used to be
+ * the nearest object. Mark those CPUs for update.
+ */
+ for_each_online_cpu(cpu) {
+ if (rmap->near[cpu].index == index) {
+ rmap->near[cpu].dist = CPU_RMAP_DIST_INF;
+ cpumask_set_cpu(cpu, update_mask);
+ }
+ }
+
+ debug_print_rmap(rmap, "after invalidating old distances");
+
+ /* Set distance to 0 for all CPUs in the new affinity mask.
+ * Mark all CPUs within their NUMA nodes for update.
+ */
+ for_each_cpu(cpu, affinity) {
+ rmap->near[cpu].index = index;
+ rmap->near[cpu].dist = 0;
+ cpumask_or(update_mask, update_mask,
+ cpumask_of_node(cpu_to_node(cpu)));
+ }
+
+ debug_print_rmap(rmap, "after updating neighbours");
+
+ /* Update distances based on topology */
+ for_each_cpu(cpu, update_mask) {
+ if (cpu_rmap_copy_neigh(rmap, cpu,
+ topology_thread_cpumask(cpu), 1))
+ continue;
+ if (cpu_rmap_copy_neigh(rmap, cpu,
+ topology_core_cpumask(cpu), 2))
+ continue;
+ if (cpu_rmap_copy_neigh(rmap, cpu,
+ cpumask_of_node(cpu_to_node(cpu)), 3))
+ continue;
+ /* We could continue into NUMA node distances, but for now
+ * we give up.
+ */
+ }
+
+ debug_print_rmap(rmap, "after copying neighbours");
+
+ free_cpumask_var(update_mask);
+ return 0;
+}
+EXPORT_SYMBOL(cpu_rmap_update);
+
+#ifdef CONFIG_GENERIC_HARDIRQS
+
+/* Glue between IRQ affinity notifiers and CPU rmaps */
+
+struct irq_glue {
+ struct irq_affinity_notify notify;
+ struct cpu_rmap *rmap;
+ u16 index;
+};
+
+/**
+ * free_irq_cpu_rmap - free a CPU affinity reverse-map used for IRQs
+ * @rmap: Reverse-map allocated with alloc_irq_cpu_map(), or %NULL
+ *
+ * Must be called in process context, before freeing the IRQs, and
+ * without holding any locks required by global workqueue items.
+ */
+void free_irq_cpu_rmap(struct cpu_rmap *rmap)
+{
+ struct irq_glue *glue;
+ u16 index;
+
+ if (!rmap)
+ return;
+
+ for (index = 0; index < rmap->used; index++) {
+ glue = rmap->obj[index];
+ irq_set_affinity_notifier(glue->notify.irq, NULL);
+ }
+ irq_run_affinity_notifiers();
+
+ kfree(rmap);
+}
+EXPORT_SYMBOL(free_irq_cpu_rmap);
+
+static void
+irq_cpu_rmap_notify(struct irq_affinity_notify *notify, const cpumask_t *mask)
+{
+ struct irq_glue *glue =
+ container_of(notify, struct irq_glue, notify);
+ int rc;
+
+ rc = cpu_rmap_update(glue->rmap, glue->index, mask);
+ if (rc)
+ pr_warning("irq_cpu_rmap_notify: update failed: %d\n", rc);
+}
+
+static void irq_cpu_rmap_release(struct kref *ref)
+{
+ struct irq_glue *glue =
+ container_of(ref, struct irq_glue, notify.kref);
+ kfree(glue);
+}
+
+/**
+ * irq_cpu_rmap_add - add an IRQ to a CPU affinity reverse-map
+ * @rmap: The reverse-map
+ * @irq: The IRQ number
+ *
+ * This adds an IRQ affinity notifier that will update the reverse-map
+ * automatically.
+ *
+ * Must be called in process context, after the IRQ is allocated but
+ * before it is bound with request_irq().
+ */
+int irq_cpu_rmap_add(struct cpu_rmap *rmap, int irq)
+{
+ struct irq_glue *glue = kzalloc(sizeof(*glue), GFP_KERNEL);
+ int rc;
+
+ if (!glue)
+ return -ENOMEM;
+ glue->notify.notify = irq_cpu_rmap_notify;
+ glue->notify.release = irq_cpu_rmap_release;
+ glue->rmap = rmap;
+ glue->index = cpu_rmap_add(rmap, glue);
+ rc = irq_set_affinity_notifier(irq, &glue->notify);
+ if (rc)
+ kfree(glue);
+ return rc;
+}
+EXPORT_SYMBOL(irq_cpu_rmap_add);
+
+#endif /* CONFIG_GENERIC_HARDIRQS */
diff --git a/lib/debugobjects.c b/lib/debugobjects.c
index deebcc5..9d86e45 100644
--- a/lib/debugobjects.c
+++ b/lib/debugobjects.c
@@ -249,14 +249,17 @@ static struct debug_bucket *get_bucket(unsigned long addr)
static void debug_print_object(struct debug_obj *obj, char *msg)
{
+ struct debug_obj_descr *descr = obj->descr;
static int limit;
- if (limit < 5 && obj->descr != descr_test) {
+ if (limit < 5 && descr != descr_test) {
+ void *hint = descr->debug_hint ?
+ descr->debug_hint(obj->object) : NULL;
limit++;
WARN(1, KERN_ERR "ODEBUG: %s %s (active state %u) "
- "object type: %s\n",
+ "object type: %s hint: %pS\n",
msg, obj_states[obj->state], obj->astate,
- obj->descr->name);
+ descr->name, hint);
}
debug_objects_warnings++;
}
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index b335acb..75ca78f 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -7,6 +7,7 @@
* Copyright (C) 2008 Jason Baron <jbaron@redhat.com>
* By Greg Banks <gnb@melbourne.sgi.com>
* Copyright (c) 2008 Silicon Graphics Inc. All Rights Reserved.
+ * Copyright (C) 2011 Bart Van Assche. All Rights Reserved.
*/
#include <linux/kernel.h>
@@ -27,6 +28,8 @@
#include <linux/debugfs.h>
#include <linux/slab.h>
#include <linux/jump_label.h>
+#include <linux/hardirq.h>
+#include <linux/sched.h>
extern struct _ddebug __start___verbose[];
extern struct _ddebug __stop___verbose[];
@@ -63,15 +66,25 @@ static inline const char *basename(const char *path)
return tail ? tail+1 : path;
}
+static struct { unsigned flag:8; char opt_char; } opt_array[] = {
+ { _DPRINTK_FLAGS_PRINT, 'p' },
+ { _DPRINTK_FLAGS_INCL_MODNAME, 'm' },
+ { _DPRINTK_FLAGS_INCL_FUNCNAME, 'f' },
+ { _DPRINTK_FLAGS_INCL_LINENO, 'l' },
+ { _DPRINTK_FLAGS_INCL_TID, 't' },
+};
+
/* format a string into buf[] which describes the _ddebug's flags */
static char *ddebug_describe_flags(struct _ddebug *dp, char *buf,
size_t maxlen)
{
char *p = buf;
+ int i;
BUG_ON(maxlen < 4);
- if (dp->flags & _DPRINTK_FLAGS_PRINT)
- *p++ = 'p';
+ for (i = 0; i < ARRAY_SIZE(opt_array); ++i)
+ if (dp->flags & opt_array[i].flag)
+ *p++ = opt_array[i].opt_char;
if (p == buf)
*p++ = '-';
*p = '\0';
@@ -343,7 +356,7 @@ static int ddebug_parse_flags(const char *str, unsigned int *flagsp,
unsigned int *maskp)
{
unsigned flags = 0;
- int op = '=';
+ int op = '=', i;
switch (*str) {
case '+':
@@ -358,13 +371,14 @@ static int ddebug_parse_flags(const char *str, unsigned int *flagsp,
printk(KERN_INFO "%s: op='%c'\n", __func__, op);
for ( ; *str ; ++str) {
- switch (*str) {
- case 'p':
- flags |= _DPRINTK_FLAGS_PRINT;
- break;
- default:
- return -EINVAL;
+ for (i = ARRAY_SIZE(opt_array) - 1; i >= 0; i--) {
+ if (*str == opt_array[i].opt_char) {
+ flags |= opt_array[i].flag;
+ break;
+ }
}
+ if (i < 0)
+ return -EINVAL;
}
if (flags == 0)
return -EINVAL;
@@ -413,6 +427,35 @@ static int ddebug_exec_query(char *query_string)
return 0;
}
+int __dynamic_pr_debug(struct _ddebug *descriptor, const char *fmt, ...)
+{
+ va_list args;
+ int res;
+
+ BUG_ON(!descriptor);
+ BUG_ON(!fmt);
+
+ va_start(args, fmt);
+ res = printk(KERN_DEBUG);
+ if (descriptor->flags & _DPRINTK_FLAGS_INCL_TID) {
+ if (in_interrupt())
+ res += printk(KERN_CONT "<intr> ");
+ else
+ res += printk(KERN_CONT "[%d] ", task_pid_vnr(current));
+ }
+ if (descriptor->flags & _DPRINTK_FLAGS_INCL_MODNAME)
+ res += printk(KERN_CONT "%s:", descriptor->modname);
+ if (descriptor->flags & _DPRINTK_FLAGS_INCL_FUNCNAME)
+ res += printk(KERN_CONT "%s:", descriptor->function);
+ if (descriptor->flags & _DPRINTK_FLAGS_INCL_LINENO)
+ res += printk(KERN_CONT "%d ", descriptor->lineno);
+ res += vprintk(fmt, args);
+ va_end(args);
+
+ return res;
+}
+EXPORT_SYMBOL(__dynamic_pr_debug);
+
static __initdata char ddebug_setup_string[1024];
static __init int ddebug_setup_query(char *str)
{
diff --git a/lib/nlattr.c b/lib/nlattr.c
index 5021cbc..ac09f22 100644
--- a/lib/nlattr.c
+++ b/lib/nlattr.c
@@ -148,7 +148,7 @@ nla_policy_len(const struct nla_policy *p, int n)
{
int i, len = 0;
- for (i = 0; i < n; i++) {
+ for (i = 0; i < n; i++, p++) {
if (p->len)
len += nla_total_size(p->len);
else if (nla_attr_minlen[p->type])
diff --git a/lib/plist.c b/lib/plist.c
index 1471988..0ae7e64 100644
--- a/lib/plist.c
+++ b/lib/plist.c
@@ -28,6 +28,8 @@
#ifdef CONFIG_DEBUG_PI_LIST
+static struct plist_head test_head;
+
static void plist_check_prev_next(struct list_head *t, struct list_head *p,
struct list_head *n)
{
@@ -54,12 +56,13 @@ static void plist_check_list(struct list_head *top)
static void plist_check_head(struct plist_head *head)
{
- WARN_ON(!head->rawlock && !head->spinlock);
+ WARN_ON(head != &test_head && !head->rawlock && !head->spinlock);
if (head->rawlock)
WARN_ON_SMP(!raw_spin_is_locked(head->rawlock));
if (head->spinlock)
WARN_ON_SMP(!spin_is_locked(head->spinlock));
- plist_check_list(&head->prio_list);
+ if (!plist_head_empty(head))
+ plist_check_list(&plist_first(head)->prio_list);
plist_check_list(&head->node_list);
}
@@ -75,25 +78,33 @@ static void plist_check_head(struct plist_head *head)
*/
void plist_add(struct plist_node *node, struct plist_head *head)
{
- struct plist_node *iter;
+ struct plist_node *first, *iter, *prev = NULL;
+ struct list_head *node_next = &head->node_list;
plist_check_head(head);
WARN_ON(!plist_node_empty(node));
+ WARN_ON(!list_empty(&node->prio_list));
+
+ if (plist_head_empty(head))
+ goto ins_node;
- list_for_each_entry(iter, &head->prio_list, plist.prio_list) {
- if (node->prio < iter->prio)
- goto lt_prio;
- else if (node->prio == iter->prio) {
- iter = list_entry(iter->plist.prio_list.next,
- struct plist_node, plist.prio_list);
- goto eq_prio;
+ first = iter = plist_first(head);
+
+ do {
+ if (node->prio < iter->prio) {
+ node_next = &iter->node_list;
+ break;
}
- }
-lt_prio:
- list_add_tail(&node->plist.prio_list, &iter->plist.prio_list);
-eq_prio:
- list_add_tail(&node->plist.node_list, &iter->plist.node_list);
+ prev = iter;
+ iter = list_entry(iter->prio_list.next,
+ struct plist_node, prio_list);
+ } while (iter != first);
+
+ if (!prev || prev->prio != node->prio)
+ list_add_tail(&node->prio_list, &iter->prio_list);
+ins_node:
+ list_add_tail(&node->node_list, node_next);
plist_check_head(head);
}
@@ -108,14 +119,98 @@ void plist_del(struct plist_node *node, struct plist_head *head)
{
plist_check_head(head);
- if (!list_empty(&node->plist.prio_list)) {
- struct plist_node *next = plist_first(&node->plist);
+ if (!list_empty(&node->prio_list)) {
+ if (node->node_list.next != &head->node_list) {
+ struct plist_node *next;
+
+ next = list_entry(node->node_list.next,
+ struct plist_node, node_list);
- list_move_tail(&next->plist.prio_list, &node->plist.prio_list);
- list_del_init(&node->plist.prio_list);
+ /* add the next plist_node into prio_list */
+ if (list_empty(&next->prio_list))
+ list_add(&next->prio_list, &node->prio_list);
+ }
+ list_del_init(&node->prio_list);
}
- list_del_init(&node->plist.node_list);
+ list_del_init(&node->node_list);
plist_check_head(head);
}
+
+#ifdef CONFIG_DEBUG_PI_LIST
+#include <linux/sched.h>
+#include <linux/module.h>
+#include <linux/init.h>
+
+static struct plist_node __initdata test_node[241];
+
+static void __init plist_test_check(int nr_expect)
+{
+ struct plist_node *first, *prio_pos, *node_pos;
+
+ if (plist_head_empty(&test_head)) {
+ BUG_ON(nr_expect != 0);
+ return;
+ }
+
+ prio_pos = first = plist_first(&test_head);
+ plist_for_each(node_pos, &test_head) {
+ if (nr_expect-- < 0)
+ break;
+ if (node_pos == first)
+ continue;
+ if (node_pos->prio == prio_pos->prio) {
+ BUG_ON(!list_empty(&node_pos->prio_list));
+ continue;
+ }
+
+ BUG_ON(prio_pos->prio > node_pos->prio);
+ BUG_ON(prio_pos->prio_list.next != &node_pos->prio_list);
+ prio_pos = node_pos;
+ }
+
+ BUG_ON(nr_expect != 0);
+ BUG_ON(prio_pos->prio_list.next != &first->prio_list);
+}
+
+static int __init plist_test(void)
+{
+ int nr_expect = 0, i, loop;
+ unsigned int r = local_clock();
+
+ printk(KERN_INFO "start plist test\n");
+ plist_head_init(&test_head, NULL);
+ for (i = 0; i < ARRAY_SIZE(test_node); i++)
+ plist_node_init(test_node + i, 0);
+
+ for (loop = 0; loop < 1000; loop++) {
+ r = r * 193939 % 47629;
+ i = r % ARRAY_SIZE(test_node);
+ if (plist_node_empty(test_node + i)) {
+ r = r * 193939 % 47629;
+ test_node[i].prio = r % 99;
+ plist_add(test_node + i, &test_head);
+ nr_expect++;
+ } else {
+ plist_del(test_node + i, &test_head);
+ nr_expect--;
+ }
+ plist_test_check(nr_expect);
+ }
+
+ for (i = 0; i < ARRAY_SIZE(test_node); i++) {
+ if (plist_node_empty(test_node + i))
+ continue;
+ plist_del(test_node + i, &test_head);
+ nr_expect--;
+ plist_test_check(nr_expect);
+ }
+
+ printk(KERN_INFO "end plist test\n");
+ return 0;
+}
+
+module_init(plist_test);
+
+#endif
diff --git a/lib/rwsem.c b/lib/rwsem.c
index f236d7c..aa7c305 100644
--- a/lib/rwsem.c
+++ b/lib/rwsem.c
@@ -222,8 +222,7 @@ rwsem_down_failed_common(struct rw_semaphore *sem,
/*
* wait for the read lock to be granted
*/
-asmregparm struct rw_semaphore __sched *
-rwsem_down_read_failed(struct rw_semaphore *sem)
+struct rw_semaphore __sched *rwsem_down_read_failed(struct rw_semaphore *sem)
{
return rwsem_down_failed_common(sem, RWSEM_WAITING_FOR_READ,
-RWSEM_ACTIVE_READ_BIAS);
@@ -232,8 +231,7 @@ rwsem_down_read_failed(struct rw_semaphore *sem)
/*
* wait for the write lock to be granted
*/
-asmregparm struct rw_semaphore __sched *
-rwsem_down_write_failed(struct rw_semaphore *sem)
+struct rw_semaphore __sched *rwsem_down_write_failed(struct rw_semaphore *sem)
{
return rwsem_down_failed_common(sem, RWSEM_WAITING_FOR_WRITE,
-RWSEM_ACTIVE_WRITE_BIAS);
@@ -243,7 +241,7 @@ rwsem_down_write_failed(struct rw_semaphore *sem)
* handle waking up a waiter on the semaphore
* - up_read/up_write has decremented the active part of count if we come here
*/
-asmregparm struct rw_semaphore *rwsem_wake(struct rw_semaphore *sem)
+struct rw_semaphore *rwsem_wake(struct rw_semaphore *sem)
{
unsigned long flags;
@@ -263,7 +261,7 @@ asmregparm struct rw_semaphore *rwsem_wake(struct rw_semaphore *sem)
* - caller incremented waiting part of count and discovered it still negative
* - just wake up any readers at the front of the queue
*/
-asmregparm struct rw_semaphore *rwsem_downgrade_wake(struct rw_semaphore *sem)
+struct rw_semaphore *rwsem_downgrade_wake(struct rw_semaphore *sem)
{
unsigned long flags;
diff --git a/lib/swiotlb.c b/lib/swiotlb.c
index c47bbe1..93ca08b 100644
--- a/lib/swiotlb.c
+++ b/lib/swiotlb.c
@@ -686,8 +686,10 @@ dma_addr_t swiotlb_map_page(struct device *dev, struct page *page,
/*
* Ensure that the address returned is DMA'ble
*/
- if (!dma_capable(dev, dev_addr, size))
- panic("map_single: bounce buffer is not DMA'ble");
+ if (!dma_capable(dev, dev_addr, size)) {
+ swiotlb_tbl_unmap_single(dev, map, size, dir);
+ dev_addr = swiotlb_virt_to_bus(dev, io_tlb_overflow_buffer);
+ }
return dev_addr;
}
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