api: include an API call to request MSI access

11b9153d · Wesley W. Terpstra · d905e360 · 11b9153d · 11b9153d
Commit 11b9153d authored Apr 27, 2016 by Wesley W. Terpstra
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etherbone.h api/etherbone.h +21 -0

device.c api/glue/device.c +38 -0

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--- a/api/etherbone.h
+++ b/api/etherbone.h
@@ -435,6 +435,21 @@ eb_status_t eb_device_open_nb(eb_socket_t    socket,
                              eb_user_data_t user_data,
                              eb_callback_t  callback);

+/* Enable MSI delivery for this master.
+ * If successful, the msi_first and msi_last range will be filled with a range
+ * of addresses on which MSI accesses can be received.
+ *
+ * Return codes:
+ *   OK         - MSI enabled
+ *   BUSY       - No more MSI resources were available
+ *   ABI        - No MSI supported by hardware
+ *   FAIL       - Failed due to hardware-specific error
+ */
+EB_PUBLIC
+eb_status_t eb_device_enable_msi(eb_device_t device,
+                                 eb_address_t *msi_first,
+                                 eb_address_t *msi_last);
+
 /* Open a remote Etherbone device at 'address' (default port 0xEBD0) passively.
 * The channel is opened and the remote device should initiate the EB exchange.
 * This is useful for stream protocols where the master cannot be the initiator.
@@ -754,6 +769,8 @@ class Device {
    
    width_t width() const;
    
+    EB_STATUS_OR_VOID_T enable_msi(eb_address_t* msi_first, eb_address_t* msi_last);
+    
    template <typename T>
    EB_STATUS_OR_VOID_T sdb_scan_bus(const struct sdb_bridge* bridge, T* user, sdb_callback_t);
    template <typename T>
@@ -959,6 +976,10 @@ inline width_t Device::width() const {
  return eb_device_width(device);
 }

+inline EB_STATUS_OR_VOID_T Device::enable_msi(eb_address_t* msi_first, eb_address_t* msi_last) {
+  EB_RETURN_OR_THROW("Device::enable_msi", eb_device_enable_msi(device, msi_first, msi_last));
+}
+
 template <typename T>
 inline EB_STATUS_OR_VOID_T Device::sdb_scan_bus(const struct sdb_bridge* bridge, T* user, sdb_callback_t cb) {
  EB_RETURN_OR_THROW("Device::sdb_scan_bus", eb_sdb_scan_bus(device, bridge, user, cb));

--- a/api/glue/device.c
+++ b/api/glue/device.c
@@ -166,6 +166,44 @@ eb_status_t eb_device_open(eb_socket_t socketp, const char* address, eb_width_t
  return EB_OK;
 }

+eb_status_t eb_device_enable_msi(eb_device_t device, eb_address_t *msi_first, eb_address_t *msi_last) {
+  eb_status_t status;
+  eb_cycle_t cycle;
+  eb_data_t code, low[8], high[8];
+  eb_address_t first, last;
+  int stride, i;
+  
+  /* How big is the largest access we can make? */
+  stride = eb_device_width(device) & EB_DATAX;
+  
+  if ((status = eb_cycle_open(device, 0, 0, &cycle)) != EB_OK) return status;
+  
+  /* Config space is always bigendian */
+  eb_cycle_write_config(cycle, 40-stride, EB_BIG_ENDIAN|stride, 1);
+  eb_cycle_read_config (cycle, 48-stride, EB_BIG_ENDIAN|stride, &code);
+  
+  for (i = 0; i < 8; i += stride)
+    eb_cycle_read_config(cycle, 48+i, EB_BIG_ENDIAN|stride, &low[i]);
+  for (i = 0; i < 8; i += stride)
+    eb_cycle_read_config(cycle, 56+i, EB_BIG_ENDIAN|stride, &high[i]);
+  
+  if ((status = eb_cycle_close_silently(cycle)) != EB_OK) return status;
+  
+  /* Combine the read words */
+  first = 0; for (i = 0; i < 8; i += stride) first = (first << (8*stride)) | low[i];
+  last  = 0; for (i = 0; i < 8; i += stride) last  = (last  << (8*stride)) | high[i];
+  
+  *msi_first = first;
+  *msi_last  = last;
+  
+  switch (code) {
+  case 1:  return EB_OK;
+  case 2:  return EB_ABI;
+  case 3:  return EB_BUSY;
+  default: return EB_FAIL;
+  }
+}
+
 eb_status_t eb_socket_passive(eb_socket_t socketp, const char* address) {
  eb_device_t devicep;
  eb_transport_t transportp;