[Xen-devel] [PATCH 10/13] xen: introduce xen_event_channel_register_3level

[Wei Liu <wei.liu2@xxxxxxxxxx>]

Signed-off-by: Wei Liu <wei.liu2@xxxxxxxxxx>
---
 drivers/xen/events.c |   94 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 94 insertions(+)

diff --git a/drivers/xen/events.c b/drivers/xen/events.c
index d953e81..9038211 100644
--- a/drivers/xen/events.c
+++ b/drivers/xen/events.c
@@ -53,6 +53,9 @@
 
 /* Helper macro(s) */
 #define LONG_BITORDER (BITS_PER_LONG == 64 ? 6 : 5)
+/* event bitmap size: 1 page for 32 bit and 8 pages for 64 bit */
+#define BITMAP_PG_ORDER (BITS_PER_LONG == 64 ? 3 : 1)
+#define BITMAP_NR_PAGES (BITMAP_PG_ORDER == 3 ? 8 : 1)
 
 /* N-level event channel, starting from 2 */
 unsigned int evtchn_level = 2;
@@ -2123,6 +2126,97 @@ void xen_callback_vector(void)
 void xen_callback_vector(void) {}
 #endif
 
+static int xen_event_channel_register_3level(void)
+{
+       evtchn_register_nlevel_t reg;
+       int i, cpu;
+       unsigned long *_evtchn_pending = NULL;
+       unsigned long *_evtchn_mask = NULL;
+       unsigned long *l2sel_mfns = NULL;
+       unsigned long *l2sel_offsets = NULL;
+       int rc;
+
+       /* If we come from restore path, we don't need to allocate
+        * pages.
+        */
+       if (!evtchn_pending && !evtchn_mask) {
+               evtchn_pending =
+                       (unsigned long *)__get_free_pages(GFP_KERNEL,
+                                                         BITMAP_PG_ORDER);
+               evtchn_mask =
+                       (unsigned long *)__get_free_pages(GFP_KERNEL,
+                                                         BITMAP_PG_ORDER);
+               if (!evtchn_pending || !evtchn_mask) {
+                       free_pages((unsigned long)evtchn_pending, 
BITMAP_NR_PAGES);
+                       free_pages((unsigned long)evtchn_mask, BITMAP_NR_PAGES);
+                       evtchn_pending = NULL;
+                       evtchn_mask = NULL;
+                       rc = -ENOMEM;
+                       goto err;
+               }
+       }
+
+       rc = -ENOMEM; /* Common error code for following operations */
+#define __ALLOC_ARRAY(_ptr, _nr)                                       \
+       do {                                                            \
+               (_ptr) = kzalloc(sizeof(unsigned long) * (_nr),         \
+                                GFP_KERNEL);                           \
+               if (!(_ptr))                                            \
+                       goto out;                                       \
+       } while (0)
+
+       __ALLOC_ARRAY(_evtchn_pending, BITMAP_NR_PAGES);
+       __ALLOC_ARRAY(_evtchn_mask, BITMAP_NR_PAGES);
+       __ALLOC_ARRAY(l2sel_mfns, nr_cpu_ids);
+       __ALLOC_ARRAY(l2sel_offsets, nr_cpu_ids);
+#undef __ALLOC_ARRAY
+
+       memset(&reg, 0, sizeof(reg));
+
+       for (i = 0; i < BITMAP_NR_PAGES; i++) {
+               unsigned long offset = PAGE_SIZE * i;
+               _evtchn_pending[i] =
+                       arbitrary_virt_to_mfn(
+                               (void *)((unsigned long)evtchn_pending+offset));
+               _evtchn_mask[i] =
+                       arbitrary_virt_to_mfn(
+                               (void *)((unsigned long)evtchn_mask+offset));
+       }
+
+       for_each_possible_cpu(cpu) {
+               l2sel_mfns[cpu] =
+                       arbitrary_virt_to_mfn(&per_cpu(evtchn_sel_l2, cpu));
+               l2sel_offsets[cpu] =
+                       offset_in_page(&per_cpu(evtchn_sel_l2, cpu));
+       }
+
+       reg.u.l3.nr_pages = BITMAP_NR_PAGES;
+       reg.u.l3.evtchn_pending = _evtchn_pending;
+       reg.u.l3.evtchn_mask = _evtchn_mask;
+
+       reg.u.l3.nr_vcpus = nr_cpu_ids;
+       reg.u.l3.l2sel_mfns = l2sel_mfns;
+       reg.u.l3.l2sel_offsets = l2sel_offsets;
+
+       reg.level = 3;
+
+       rc = HYPERVISOR_event_channel_op(EVTCHNOP_register_nlevel, &reg);
+       if (rc) {
+               free_pages((unsigned long)evtchn_pending, BITMAP_NR_PAGES);
+               free_pages((unsigned long)evtchn_mask, BITMAP_NR_PAGES);
+               evtchn_pending = NULL;
+               evtchn_mask = NULL;
+       }
+
+out:
+       kfree(_evtchn_pending);
+       kfree(_evtchn_mask);
+       kfree(l2sel_mfns);
+       kfree(l2sel_offsets);
+err:
+       return rc;
+}
+
 void __init xen_init_IRQ(void)
 {
        int i, rc;
-- 
1.7.10.4


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