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authorDavid S. Miller <davem@davemloft.net>2015-03-03 21:16:48 -0500
committerDavid S. Miller <davem@davemloft.net>2015-03-03 21:16:48 -0500
commit71a83a6db6138b9d41d8a0b6b91cb59f6dc4742c (patch)
treef74b6e4e48257ec6ce40b95645ecb8533b9cc1f8 /drivers/xen
parentb97526f3ff95f92b107f0fb52cbb8627e395429b (diff)
parenta6c5170d1edea97c538c81e377e56c7b5c5b7e63 (diff)
downloadop-kernel-dev-71a83a6db6138b9d41d8a0b6b91cb59f6dc4742c.zip
op-kernel-dev-71a83a6db6138b9d41d8a0b6b91cb59f6dc4742c.tar.gz
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts: drivers/net/ethernet/rocker/rocker.c The rocker commit was two overlapping changes, one to rename the ->vport member to ->pport, and another making the bitmask expression use '1ULL' instead of plain '1'. Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/xen')
-rw-r--r--drivers/xen/Makefile2
-rw-r--r--drivers/xen/preempt.c44
-rw-r--r--drivers/xen/privcmd.c2
-rw-r--r--drivers/xen/xen-scsiback.c14
4 files changed, 53 insertions, 9 deletions
diff --git a/drivers/xen/Makefile b/drivers/xen/Makefile
index 2140398..2ccd359 100644
--- a/drivers/xen/Makefile
+++ b/drivers/xen/Makefile
@@ -2,7 +2,7 @@ ifeq ($(filter y, $(CONFIG_ARM) $(CONFIG_ARM64)),)
obj-$(CONFIG_HOTPLUG_CPU) += cpu_hotplug.o
endif
obj-$(CONFIG_X86) += fallback.o
-obj-y += grant-table.o features.o balloon.o manage.o
+obj-y += grant-table.o features.o balloon.o manage.o preempt.o
obj-y += events/
obj-y += xenbus/
diff --git a/drivers/xen/preempt.c b/drivers/xen/preempt.c
new file mode 100644
index 0000000..a1800c1
--- /dev/null
+++ b/drivers/xen/preempt.c
@@ -0,0 +1,44 @@
+/*
+ * Preemptible hypercalls
+ *
+ * Copyright (C) 2014 Citrix Systems R&D ltd.
+ *
+ * This source code is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ */
+
+#include <linux/sched.h>
+#include <xen/xen-ops.h>
+
+#ifndef CONFIG_PREEMPT
+
+/*
+ * Some hypercalls issued by the toolstack can take many 10s of
+ * seconds. Allow tasks running hypercalls via the privcmd driver to
+ * be voluntarily preempted even if full kernel preemption is
+ * disabled.
+ *
+ * Such preemptible hypercalls are bracketed by
+ * xen_preemptible_hcall_begin() and xen_preemptible_hcall_end()
+ * calls.
+ */
+
+DEFINE_PER_CPU(bool, xen_in_preemptible_hcall);
+EXPORT_SYMBOL_GPL(xen_in_preemptible_hcall);
+
+asmlinkage __visible void xen_maybe_preempt_hcall(void)
+{
+ if (unlikely(__this_cpu_read(xen_in_preemptible_hcall)
+ && should_resched())) {
+ /*
+ * Clear flag as we may be rescheduled on a different
+ * cpu.
+ */
+ __this_cpu_write(xen_in_preemptible_hcall, false);
+ _cond_resched();
+ __this_cpu_write(xen_in_preemptible_hcall, true);
+ }
+}
+#endif /* CONFIG_PREEMPT */
diff --git a/drivers/xen/privcmd.c b/drivers/xen/privcmd.c
index 569a13b..59ac71c 100644
--- a/drivers/xen/privcmd.c
+++ b/drivers/xen/privcmd.c
@@ -56,10 +56,12 @@ static long privcmd_ioctl_hypercall(void __user *udata)
if (copy_from_user(&hypercall, udata, sizeof(hypercall)))
return -EFAULT;
+ xen_preemptible_hcall_begin();
ret = privcmd_call(hypercall.op,
hypercall.arg[0], hypercall.arg[1],
hypercall.arg[2], hypercall.arg[3],
hypercall.arg[4]);
+ xen_preemptible_hcall_end();
return ret;
}
diff --git a/drivers/xen/xen-scsiback.c b/drivers/xen/xen-scsiback.c
index 61653a0..9faca6a 100644
--- a/drivers/xen/xen-scsiback.c
+++ b/drivers/xen/xen-scsiback.c
@@ -709,12 +709,11 @@ static int prepare_pending_reqs(struct vscsibk_info *info,
static int scsiback_do_cmd_fn(struct vscsibk_info *info)
{
struct vscsiif_back_ring *ring = &info->ring;
- struct vscsiif_request *ring_req;
+ struct vscsiif_request ring_req;
struct vscsibk_pend *pending_req;
RING_IDX rc, rp;
int err, more_to_do;
uint32_t result;
- uint8_t act;
rc = ring->req_cons;
rp = ring->sring->req_prod;
@@ -735,11 +734,10 @@ static int scsiback_do_cmd_fn(struct vscsibk_info *info)
if (!pending_req)
return 1;
- ring_req = RING_GET_REQUEST(ring, rc);
+ ring_req = *RING_GET_REQUEST(ring, rc);
ring->req_cons = ++rc;
- act = ring_req->act;
- err = prepare_pending_reqs(info, ring_req, pending_req);
+ err = prepare_pending_reqs(info, &ring_req, pending_req);
if (err) {
switch (err) {
case -ENODEV:
@@ -755,9 +753,9 @@ static int scsiback_do_cmd_fn(struct vscsibk_info *info)
return 1;
}
- switch (act) {
+ switch (ring_req.act) {
case VSCSIIF_ACT_SCSI_CDB:
- if (scsiback_gnttab_data_map(ring_req, pending_req)) {
+ if (scsiback_gnttab_data_map(&ring_req, pending_req)) {
scsiback_fast_flush_area(pending_req);
scsiback_do_resp_with_sense(NULL,
DRIVER_ERROR << 24, 0, pending_req);
@@ -768,7 +766,7 @@ static int scsiback_do_cmd_fn(struct vscsibk_info *info)
break;
case VSCSIIF_ACT_SCSI_ABORT:
scsiback_device_action(pending_req, TMR_ABORT_TASK,
- ring_req->ref_rqid);
+ ring_req.ref_rqid);
break;
case VSCSIIF_ACT_SCSI_RESET:
scsiback_device_action(pending_req, TMR_LUN_RESET, 0);
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