vfio-mdev/mtty: Simplify interrupt generation

While generating interrupt, mdev_state is already available for which
interrupt is generated.
Instead of doing indirect way from state->device->uuid-> to searching
state linearly in linked list on every interrupt generation,
directly use the available state.

Hence, simplify the code to use mdev_state and remove unused helper
function with that.

Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Parav Pandit <parav@mellanox.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

diff --git a/samples/vfio-mdev/mtty.c b/samples/vfio-mdev/mtty.c
index 92e770a06ea21b1b19f8de0e883e3d2b947cd713..ce84a300a4dafd2e6669ef55c5ca6c46d5d05e1e 100644 (file)
--- a/samples/vfio-mdev/mtty.c
+++ b/samples/vfio-mdev/mtty.c
@@ -152,20 +152,9 @@ static const struct file_operations vd_fops = {
 
 /* function prototypes */
 
-static int mtty_trigger_interrupt(const guid_t *uuid);
+static int mtty_trigger_interrupt(struct mdev_state *mdev_state);
 
 /* Helper functions */
-static struct mdev_state *find_mdev_state_by_uuid(const guid_t *uuid)
-{
-       struct mdev_state *mds;
-
-       list_for_each_entry(mds, &mdev_devices_list, next) {
-               if (guid_equal(mdev_uuid(mds->mdev), uuid))
-                       return mds;
-       }
-
-       return NULL;
-}
 
 static void dump_buffer(u8 *buf, uint32_t count)
 {
@@ -337,8 +326,7 @@ static void handle_bar_write(unsigned int index, struct mdev_state *mdev_state,
                                pr_err("Serial port %d: Fifo level trigger\n",
                                        index);
 #endif
-                               mtty_trigger_interrupt(
-                                               mdev_uuid(mdev_state->mdev));
+                               mtty_trigger_interrupt(mdev_state);
                        }
                } else {
 #if defined(DEBUG_INTR)
@@ -352,8 +340,7 @@ static void handle_bar_write(unsigned int index, struct mdev_state *mdev_state,
                         */
                        if (mdev_state->s[index].uart_reg[UART_IER] &
                                                                UART_IER_RLSI)
-                               mtty_trigger_interrupt(
-                                               mdev_uuid(mdev_state->mdev));
+                               mtty_trigger_interrupt(mdev_state);
                }
                mutex_unlock(&mdev_state->rxtx_lock);
                break;
@@ -372,8 +359,7 @@ static void handle_bar_write(unsigned int index, struct mdev_state *mdev_state,
                                pr_err("Serial port %d: IER_THRI write\n",
                                        index);
 #endif
-                               mtty_trigger_interrupt(
-                                               mdev_uuid(mdev_state->mdev));
+                               mtty_trigger_interrupt(mdev_state);
                        }
 
                        mutex_unlock(&mdev_state->rxtx_lock);
@@ -444,7 +430,7 @@ static void handle_bar_write(unsigned int index, struct mdev_state *mdev_state,
 #if defined(DEBUG_INTR)
                        pr_err("Serial port %d: MCR_OUT2 write\n", index);
 #endif
-                       mtty_trigger_interrupt(mdev_uuid(mdev_state->mdev));
+                       mtty_trigger_interrupt(mdev_state);
                }
 
                if ((mdev_state->s[index].uart_reg[UART_IER] & UART_IER_MSI) &&
@@ -452,7 +438,7 @@ static void handle_bar_write(unsigned int index, struct mdev_state *mdev_state,
 #if defined(DEBUG_INTR)
                        pr_err("Serial port %d: MCR RTS/DTR write\n", index);
 #endif
-                       mtty_trigger_interrupt(mdev_uuid(mdev_state->mdev));
+                       mtty_trigger_interrupt(mdev_state);
                }
                break;
 
@@ -503,8 +489,7 @@ static void handle_bar_read(unsigned int index, struct mdev_state *mdev_state,
 #endif
                        if (mdev_state->s[index].uart_reg[UART_IER] &
                                                         UART_IER_THRI)
-                               mtty_trigger_interrupt(
-                                       mdev_uuid(mdev_state->mdev));
+                               mtty_trigger_interrupt(mdev_state);
                }
                mutex_unlock(&mdev_state->rxtx_lock);
 
@@ -1028,17 +1013,9 @@ static int mtty_set_irqs(struct mdev_device *mdev, uint32_t flags,
        return ret;
 }
 
-static int mtty_trigger_interrupt(const guid_t *uuid)
+static int mtty_trigger_interrupt(struct mdev_state *mdev_state)
 {
        int ret = -1;
-       struct mdev_state *mdev_state;
-
-       mdev_state = find_mdev_state_by_uuid(uuid);
-
-       if (!mdev_state) {
-               pr_info("%s: mdev not found\n", __func__);
-               return -EINVAL;
-       }
 
        if ((mdev_state->irq_index == VFIO_PCI_MSI_IRQ_INDEX) &&
            (!mdev_state->msi_evtfd))