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-rw-r--r--arch/arm/include/asm/irq.h5
-rw-r--r--arch/arm64/include/asm/irq.h5
-rw-r--r--drivers/xen/events/events_base.c5
-rw-r--r--drivers/xen/evtchn.c123
-rw-r--r--drivers/xen/gntdev.c2
5 files changed, 121 insertions, 19 deletions
diff --git a/arch/arm/include/asm/irq.h b/arch/arm/include/asm/irq.h
index be1d07d59ee9..1bd9510de1b9 100644
--- a/arch/arm/include/asm/irq.h
+++ b/arch/arm/include/asm/irq.h
@@ -40,6 +40,11 @@ extern void arch_trigger_all_cpu_backtrace(bool);
#define arch_trigger_all_cpu_backtrace(x) arch_trigger_all_cpu_backtrace(x)
#endif
+static inline int nr_legacy_irqs(void)
+{
+ return NR_IRQS_LEGACY;
+}
+
#endif
#endif
diff --git a/arch/arm64/include/asm/irq.h b/arch/arm64/include/asm/irq.h
index 23eb450b820b..8e8d30684392 100644
--- a/arch/arm64/include/asm/irq.h
+++ b/arch/arm64/include/asm/irq.h
@@ -7,4 +7,9 @@ struct pt_regs;
extern void set_handle_irq(void (*handle_irq)(struct pt_regs *));
+static inline int nr_legacy_irqs(void)
+{
+ return 0;
+}
+
#endif
diff --git a/drivers/xen/events/events_base.c b/drivers/xen/events/events_base.c
index 849500e4e14d..524c22146429 100644
--- a/drivers/xen/events/events_base.c
+++ b/drivers/xen/events/events_base.c
@@ -39,6 +39,7 @@
#include <asm/irq.h>
#include <asm/idle.h>
#include <asm/io_apic.h>
+#include <asm/i8259.h>
#include <asm/xen/pci.h>
#endif
#include <asm/sync_bitops.h>
@@ -420,7 +421,7 @@ static int __must_check xen_allocate_irq_gsi(unsigned gsi)
return xen_allocate_irq_dynamic();
/* Legacy IRQ descriptors are already allocated by the arch. */
- if (gsi < NR_IRQS_LEGACY)
+ if (gsi < nr_legacy_irqs())
irq = gsi;
else
irq = irq_alloc_desc_at(gsi, -1);
@@ -446,7 +447,7 @@ static void xen_free_irq(unsigned irq)
kfree(info);
/* Legacy IRQ descriptors are managed by the arch. */
- if (irq < NR_IRQS_LEGACY)
+ if (irq < nr_legacy_irqs())
return;
irq_free_desc(irq);
diff --git a/drivers/xen/evtchn.c b/drivers/xen/evtchn.c
index 00f40f051d95..38272ad24551 100644
--- a/drivers/xen/evtchn.c
+++ b/drivers/xen/evtchn.c
@@ -49,6 +49,8 @@
#include <linux/init.h>
#include <linux/mutex.h>
#include <linux/cpu.h>
+#include <linux/mm.h>
+#include <linux/vmalloc.h>
#include <xen/xen.h>
#include <xen/events.h>
@@ -58,10 +60,10 @@
struct per_user_data {
struct mutex bind_mutex; /* serialize bind/unbind operations */
struct rb_root evtchns;
+ unsigned int nr_evtchns;
/* Notification ring, accessed via /dev/xen/evtchn. */
-#define EVTCHN_RING_SIZE (PAGE_SIZE / sizeof(evtchn_port_t))
-#define EVTCHN_RING_MASK(_i) ((_i)&(EVTCHN_RING_SIZE-1))
+ unsigned int ring_size;
evtchn_port_t *ring;
unsigned int ring_cons, ring_prod, ring_overflow;
struct mutex ring_cons_mutex; /* protect against concurrent readers */
@@ -80,10 +82,41 @@ struct user_evtchn {
bool enabled;
};
+static evtchn_port_t *evtchn_alloc_ring(unsigned int size)
+{
+ evtchn_port_t *ring;
+ size_t s = size * sizeof(*ring);
+
+ ring = kmalloc(s, GFP_KERNEL);
+ if (!ring)
+ ring = vmalloc(s);
+
+ return ring;
+}
+
+static void evtchn_free_ring(evtchn_port_t *ring)
+{
+ kvfree(ring);
+}
+
+static unsigned int evtchn_ring_offset(struct per_user_data *u,
+ unsigned int idx)
+{
+ return idx & (u->ring_size - 1);
+}
+
+static evtchn_port_t *evtchn_ring_entry(struct per_user_data *u,
+ unsigned int idx)
+{
+ return u->ring + evtchn_ring_offset(u, idx);
+}
+
static int add_evtchn(struct per_user_data *u, struct user_evtchn *evtchn)
{
struct rb_node **new = &(u->evtchns.rb_node), *parent = NULL;
+ u->nr_evtchns++;
+
while (*new) {
struct user_evtchn *this;
@@ -107,6 +140,7 @@ static int add_evtchn(struct per_user_data *u, struct user_evtchn *evtchn)
static void del_evtchn(struct per_user_data *u, struct user_evtchn *evtchn)
{
+ u->nr_evtchns--;
rb_erase(&evtchn->node, &u->evtchns);
kfree(evtchn);
}
@@ -144,8 +178,8 @@ static irqreturn_t evtchn_interrupt(int irq, void *data)
spin_lock(&u->ring_prod_lock);
- if ((u->ring_prod - u->ring_cons) < EVTCHN_RING_SIZE) {
- u->ring[EVTCHN_RING_MASK(u->ring_prod)] = evtchn->port;
+ if ((u->ring_prod - u->ring_cons) < u->ring_size) {
+ *evtchn_ring_entry(u, u->ring_prod) = evtchn->port;
wmb(); /* Ensure ring contents visible */
if (u->ring_cons == u->ring_prod++) {
wake_up_interruptible(&u->evtchn_wait);
@@ -200,10 +234,10 @@ static ssize_t evtchn_read(struct file *file, char __user *buf,
}
/* Byte lengths of two chunks. Chunk split (if any) is at ring wrap. */
- if (((c ^ p) & EVTCHN_RING_SIZE) != 0) {
- bytes1 = (EVTCHN_RING_SIZE - EVTCHN_RING_MASK(c)) *
+ if (((c ^ p) & u->ring_size) != 0) {
+ bytes1 = (u->ring_size - evtchn_ring_offset(u, c)) *
sizeof(evtchn_port_t);
- bytes2 = EVTCHN_RING_MASK(p) * sizeof(evtchn_port_t);
+ bytes2 = evtchn_ring_offset(u, p) * sizeof(evtchn_port_t);
} else {
bytes1 = (p - c) * sizeof(evtchn_port_t);
bytes2 = 0;
@@ -219,7 +253,7 @@ static ssize_t evtchn_read(struct file *file, char __user *buf,
rc = -EFAULT;
rmb(); /* Ensure that we see the port before we copy it. */
- if (copy_to_user(buf, &u->ring[EVTCHN_RING_MASK(c)], bytes1) ||
+ if (copy_to_user(buf, evtchn_ring_entry(u, c), bytes1) ||
((bytes2 != 0) &&
copy_to_user(&buf[bytes1], &u->ring[0], bytes2)))
goto unlock_out;
@@ -278,6 +312,66 @@ static ssize_t evtchn_write(struct file *file, const char __user *buf,
return rc;
}
+static int evtchn_resize_ring(struct per_user_data *u)
+{
+ unsigned int new_size;
+ evtchn_port_t *new_ring, *old_ring;
+ unsigned int p, c;
+
+ /*
+ * Ensure the ring is large enough to capture all possible
+ * events. i.e., one free slot for each bound event.
+ */
+ if (u->nr_evtchns <= u->ring_size)
+ return 0;
+
+ if (u->ring_size == 0)
+ new_size = 64;
+ else
+ new_size = 2 * u->ring_size;
+
+ new_ring = evtchn_alloc_ring(new_size);
+ if (!new_ring)
+ return -ENOMEM;
+
+ old_ring = u->ring;
+
+ /*
+ * Access to the ring contents is serialized by either the
+ * prod /or/ cons lock so take both when resizing.
+ */
+ mutex_lock(&u->ring_cons_mutex);
+ spin_lock_irq(&u->ring_prod_lock);
+
+ /*
+ * Copy the old ring contents to the new ring.
+ *
+ * If the ring contents crosses the end of the current ring,
+ * it needs to be copied in two chunks.
+ *
+ * +---------+ +------------------+
+ * |34567 12| -> | 1234567 |
+ * +-----p-c-+ +------------------+
+ */
+ p = evtchn_ring_offset(u, u->ring_prod);
+ c = evtchn_ring_offset(u, u->ring_cons);
+ if (p < c) {
+ memcpy(new_ring + c, u->ring + c, (u->ring_size - c) * sizeof(*u->ring));
+ memcpy(new_ring + u->ring_size, u->ring, p * sizeof(*u->ring));
+ } else
+ memcpy(new_ring + c, u->ring + c, (p - c) * sizeof(*u->ring));
+
+ u->ring = new_ring;
+ u->ring_size = new_size;
+
+ spin_unlock_irq(&u->ring_prod_lock);
+ mutex_unlock(&u->ring_cons_mutex);
+
+ evtchn_free_ring(old_ring);
+
+ return 0;
+}
+
static int evtchn_bind_to_user(struct per_user_data *u, int port)
{
struct user_evtchn *evtchn;
@@ -305,6 +399,10 @@ static int evtchn_bind_to_user(struct per_user_data *u, int port)
if (rc < 0)
goto err;
+ rc = evtchn_resize_ring(u);
+ if (rc < 0)
+ goto err;
+
rc = bind_evtchn_to_irqhandler(port, evtchn_interrupt, 0,
u->name, evtchn);
if (rc < 0)
@@ -503,13 +601,6 @@ static int evtchn_open(struct inode *inode, struct file *filp)
init_waitqueue_head(&u->evtchn_wait);
- u->ring = (evtchn_port_t *)__get_free_page(GFP_KERNEL);
- if (u->ring == NULL) {
- kfree(u->name);
- kfree(u);
- return -ENOMEM;
- }
-
mutex_init(&u->bind_mutex);
mutex_init(&u->ring_cons_mutex);
spin_lock_init(&u->ring_prod_lock);
@@ -532,7 +623,7 @@ static int evtchn_release(struct inode *inode, struct file *filp)
evtchn_unbind_from_user(u, evtchn);
}
- free_page((unsigned long)u->ring);
+ evtchn_free_ring(u->ring);
kfree(u->name);
kfree(u);
diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c
index 2ea0b3b2a91d..1be5dd048622 100644
--- a/drivers/xen/gntdev.c
+++ b/drivers/xen/gntdev.c
@@ -804,7 +804,7 @@ static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma)
vma->vm_ops = &gntdev_vmops;
- vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
+ vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP | VM_IO;
if (use_ptemod)
vma->vm_flags |= VM_DONTCOPY;
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-22 05:29:28 +0000