eal/linux: toggle interrupt for uio_pci_generic

enable/disable interrupt by manipulating a control bit of command
register on NIC's PCIe configuration space.

Signed-off-by: Danny Zhou <danny.zhou@intel.com>
Tested-by: Qun Wan <qun.wan@intel.com>
Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
Acked-by: Declan Doherty <declan.doherty@intel.com>

diff --git a/lib/librte_eal/linuxapp/eal/eal_interrupts.c b/lib/librte_eal/linuxapp/eal/eal_interrupts.c
index dc2668a..8c5b834 100644 (file)
--- a/lib/librte_eal/linuxapp/eal/eal_interrupts.c
+++ b/lib/librte_eal/linuxapp/eal/eal_interrupts.c
@@ -361,6 +361,54 @@ vfio_disable_msix(struct rte_intr_handle *intr_handle) {
 }
 #endif
 
+static int
+uio_intr_disable(struct rte_intr_handle *intr_handle)
+{
+       unsigned char command_high;
+
+       /* use UIO config file descriptor for uio_pci_generic */
+       if (pread(intr_handle->uio_cfg_fd, &command_high, 1, 5) != 1) {
+               RTE_LOG(ERR, EAL,
+                       "Error reading interrupts status for fd %d\n",
+                       intr_handle->uio_cfg_fd);
+               return -1;
+       }
+       /* disable interrupts */
+       command_high |= 0x4;
+       if (pwrite(intr_handle->uio_cfg_fd, &command_high, 1, 5) != 1) {
+               RTE_LOG(ERR, EAL,
+                       "Error disabling interrupts for fd %d\n",
+                       intr_handle->uio_cfg_fd);
+               return -1;
+       }
+
+       return 0;
+}
+
+static int
+uio_intr_enable(struct rte_intr_handle *intr_handle)
+{
+       unsigned char command_high;
+
+       /* use UIO config file descriptor for uio_pci_generic */
+       if (pread(intr_handle->uio_cfg_fd, &command_high, 1, 5) != 1) {
+               RTE_LOG(ERR, EAL,
+                       "Error reading interrupts status for fd %d\n",
+                       intr_handle->uio_cfg_fd);
+               return -1;
+       }
+       /* enable interrupts */
+       command_high &= ~0x4;
+       if (pwrite(intr_handle->uio_cfg_fd, &command_high, 1, 5) != 1) {
+               RTE_LOG(ERR, EAL,
+                       "Error enabling interrupts for fd %d\n",
+                       intr_handle->uio_cfg_fd);
+               return -1;
+       }
+
+       return 0;
+}
+
 int
 rte_intr_callback_register(struct rte_intr_handle *intr_handle,
                        rte_intr_callback_fn cb, void *cb_arg)
@@ -500,20 +548,14 @@ rte_intr_callback_unregister(struct rte_intr_handle *intr_handle,
 int
 rte_intr_enable(struct rte_intr_handle *intr_handle)
 {
-       const int value = 1;
-
-       if (!intr_handle || intr_handle->fd < 0)
+       if (!intr_handle || intr_handle->fd < 0 || intr_handle->uio_cfg_fd < 0)
                return -1;
 
        switch (intr_handle->type){
        /* write to the uio fd to enable the interrupt */
        case RTE_INTR_HANDLE_UIO:
-               if (write(intr_handle->fd, &value, sizeof(value)) < 0) {
-                       RTE_LOG(ERR, EAL,
-                               "Error enabling interrupts for fd %d\n",
-                                                       intr_handle->fd);
+               if (uio_intr_enable(intr_handle))
                        return -1;
-               }
                break;
        /* not used at this moment */
        case RTE_INTR_HANDLE_ALARM:
@@ -546,20 +588,14 @@ rte_intr_enable(struct rte_intr_handle *intr_handle)
 int
 rte_intr_disable(struct rte_intr_handle *intr_handle)
 {
-       const int value = 0;
-
-       if (!intr_handle || intr_handle->fd < 0)
+       if (!intr_handle || intr_handle->fd < 0 || intr_handle->uio_cfg_fd < 0)
                return -1;
 
        switch (intr_handle->type){
        /* write to the uio fd to disable the interrupt */
        case RTE_INTR_HANDLE_UIO:
-               if (write(intr_handle->fd, &value, sizeof(value)) < 0){
-                       RTE_LOG(ERR, EAL,
-                               "Error disabling interrupts for fd %d\n",
-                                                       intr_handle->fd);
+               if (uio_intr_disable(intr_handle))
                        return -1;
-               }
                break;
        /* not used at this moment */
        case RTE_INTR_HANDLE_ALARM: