layerscape: add patches-5.4

[openwrt/staging/wigyori.git] / target / linux / layerscape / patches-5.4 / 809-jailhouse-0003-ivshmem-net-fix-race-in-state-machine.patch

diff --git a/target/linux/layerscape/patches-5.4/809-jailhouse-0003-ivshmem-net-fix-race-in-state-machine.patch b/target/linux/layerscape/patches-5.4/809-jailhouse-0003-ivshmem-net-fix-race-in-state-machine.patch
new file mode 100644 (file)
index 0000000..ae6f839
--- /dev/null
+++ b/target/linux/layerscape/patches-5.4/809-jailhouse-0003-ivshmem-net-fix-race-in-state-machine.patch
@@ -0,0 +1,136 @@
+From 0af5d7d021bb899d9c3880415267e178a20fb7a9 Mon Sep 17 00:00:00 2001
+From: Mans Rullgard <mans@mansr.com>
+Date: Thu, 24 Nov 2016 18:46:41 +0000
+Subject: [PATCH] ivshmem-net: fix race in state machine
+
+(cherry picked from commit 5d663baed6a89d09bae4446f6509f9957c780bc7)
+---
+ drivers/net/ivshmem-net.c | 60 ++++++++++++++++++++++++-----------------------
+ 1 file changed, 31 insertions(+), 29 deletions(-)
+
+--- a/drivers/net/ivshmem-net.c
++++ b/drivers/net/ivshmem-net.c
+@@ -36,6 +36,8 @@
+ #define IVSHM_NET_STATE_READY 2
+ #define IVSHM_NET_STATE_RUN   3
+ 
++#define IVSHM_NET_FLAG_RUN    0
++
+ #define IVSHM_NET_MTU_MIN 256
+ #define IVSHM_NET_MTU_MAX 65535
+ #define IVSHM_NET_MTU_DEF 16384
+@@ -96,6 +98,8 @@ struct ivshm_net {
+       u32 lstate;
+       u32 rstate;
+ 
++      unsigned long flags;
++
+       struct workqueue_struct *state_wq;
+       struct work_struct state_work;
+ 
+@@ -529,12 +533,32 @@ static void ivshm_net_run(struct net_dev
+ {
+       struct ivshm_net *in = netdev_priv(ndev);
+ 
++      if (in->lstate < IVSHM_NET_STATE_READY)
++              return;
++
++      if (!netif_running(ndev))
++              return;
++
++      if (test_and_set_bit(IVSHM_NET_FLAG_RUN, &in->flags))
++              return;
++
+       netif_start_queue(ndev);
+       napi_enable(&in->napi);
+       napi_schedule(&in->napi);
+       ivshm_net_set_state(in, IVSHM_NET_STATE_RUN);
+ }
+ 
++static void ivshm_net_do_stop(struct net_device *ndev)
++{
++      struct ivshm_net *in = netdev_priv(ndev);
++
++      if (!test_and_clear_bit(IVSHM_NET_FLAG_RUN, &in->flags))
++              return;
++
++      netif_stop_queue(ndev);
++      napi_disable(&in->napi);
++}
++
+ static void ivshm_net_state_change(struct work_struct *work)
+ {
+       struct ivshm_net *in = container_of(work, struct ivshm_net, state_work);
+@@ -560,21 +584,13 @@ static void ivshm_net_state_change(struc
+               break;
+ 
+       case IVSHM_NET_STATE_READY:
++      case IVSHM_NET_STATE_RUN:
+               if (rstate >= IVSHM_NET_STATE_READY) {
+                       netif_carrier_on(ndev);
+-                      if (ndev->flags & IFF_UP)
+-                              ivshm_net_run(ndev);
++                      ivshm_net_run(ndev);
+               } else {
+                       netif_carrier_off(ndev);
+-                      ivshm_net_set_state(in, IVSHM_NET_STATE_RESET);
+-              }
+-              break;
+-
+-      case IVSHM_NET_STATE_RUN:
+-              if (rstate < IVSHM_NET_STATE_READY) {
+-                      netif_stop_queue(ndev);
+-                      napi_disable(&in->napi);
+-                      netif_carrier_off(ndev);
++                      ivshm_net_do_stop(ndev);
+                       ivshm_net_set_state(in, IVSHM_NET_STATE_RESET);
+               }
+               break;
+@@ -584,18 +600,13 @@ static void ivshm_net_state_change(struc
+       WRITE_ONCE(in->rstate, rstate);
+ }
+ 
+-static bool ivshm_net_check_state(struct net_device *ndev)
++static void ivshm_net_check_state(struct net_device *ndev)
+ {
+       struct ivshm_net *in = netdev_priv(ndev);
+       u32 rstate = readl(&in->ivshm_regs->rstate);
+ 
+-      if (rstate != READ_ONCE(in->rstate) ||
+-          in->lstate != IVSHM_NET_STATE_RUN) {
++      if (rstate != in->rstate || !test_bit(IVSHM_NET_FLAG_RUN, &in->flags))
+               queue_work(in->state_wq, &in->state_work);
+-              return false;
+-      }
+-
+-      return true;
+ }
+ 
+ static irqreturn_t ivshm_net_int(int irq, void *data)
+@@ -617,24 +628,15 @@ static int ivshm_net_open(struct net_dev
+ 
+       netdev_reset_queue(ndev);
+       ndev->operstate = IF_OPER_UP;
+-
+-      if (in->lstate == IVSHM_NET_STATE_READY)
+-              ivshm_net_run(ndev);
++      ivshm_net_run(ndev);
+ 
+       return 0;
+ }
+ 
+ static int ivshm_net_stop(struct net_device *ndev)
+ {
+-      struct ivshm_net *in = netdev_priv(ndev);
+-
+       ndev->operstate = IF_OPER_DOWN;
+-
+-      if (in->lstate == IVSHM_NET_STATE_RUN) {
+-              napi_disable(&in->napi);
+-              netif_stop_queue(ndev);
+-              ivshm_net_set_state(in, IVSHM_NET_STATE_READY);
+-      }
++      ivshm_net_do_stop(ndev);
+ 
+       return 0;
+ }