[efi] Rewrite SNP NIC driver

Rewrite the SNP NIC driver to use non-blocking and deferrable
transmissions, to provide link status detection, to provide
information about the underlying (PCI) hardware device, and to avoid
unnecessary I/O buffer allocations during receive polling.

Signed-off-by: Michael Brown <mcb30@ipxe.org>

1 files changed, 20 insertions, 92 deletions

diff --git a/src/drivers/net/efi/snponly.c b/src/drivers/net/efi/snponly.c
index 6fcc54a0..de55bd0d 100644
--- a/src/drivers/net/efi/snponly.c
+++ b/src/drivers/net/efi/snponly.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2010 VMware, Inc.  All Rights Reserved.
+ * Copyright (C) 2014 Michael Brown <mbrown@fensystems.co.uk>.
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License as
@@ -13,117 +13,45 @@
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
  */
 
 FILE_LICENCE ( GPL2_OR_LATER );
 
-#include <string.h>
 #include <errno.h>
-#include <ipxe/device.h>
-#include <ipxe/init.h>
 #include <ipxe/efi/efi.h>
-#include <ipxe/efi/Protocol/SimpleNetwork.h>
-#include "snp.h"
+#include <ipxe/efi/efi_driver.h>
 #include "snpnet.h"
 
 /** @file
  *
- * Chain-loading Simple Network Protocol Bus Driver
+ * SNP chainloaded-device-only driver
  *
- * This bus driver allows iPXE to use the EFI Simple Network Protocol provided
- * by the platform to transmit and receive packets. It attaches to only the
- * device handle that iPXE was loaded from, that is, it will only use the
- * Simple Network Protocol on the current loaded image's device handle.
- *
- * Eseentially, this driver provides the EFI equivalent of the "undionly"
- * driver.
  */
 
-/** The one and only SNP network device */
-static struct snp_device snponly_dev;
-
-/** EFI simple network protocol GUID */
-static EFI_GUID efi_simple_network_protocol_guid
-	= EFI_SIMPLE_NETWORK_PROTOCOL_GUID;
-
 /**
- * Probe SNP root bus
+ * Check to see if driver supports a device
  *
- * @v rootdev		SNP bus root device
- *
- * Look at the loaded image's device handle and see if the simple network
- * protocol exists. If so, register a driver for it.
+ * @v device		EFI device handle
+ * @ret rc		Return status code
  */
-static int snpbus_probe ( struct root_device *rootdev ) {
-	EFI_BOOT_SERVICES *bs = efi_systab->BootServices;
-	EFI_STATUS efirc;
-	int rc;
-	void *snp;
-
-	efirc = bs->OpenProtocol ( efi_loaded_image->DeviceHandle,
-				   &efi_simple_network_protocol_guid,
-				   &snp, efi_image_handle, NULL,
-				   EFI_OPEN_PROTOCOL_GET_PROTOCOL );
-	if ( efirc ) {
-		DBG ( "Could not find Simple Network Protocol!\n" );
-		return -ENODEV;
-	}
-	snponly_dev.snp = snp;
+static int snponly_supported ( EFI_HANDLE device ) {
 
-	/* Add to device hierarchy */
-	strncpy ( snponly_dev.dev.name, "EFI SNP",
-		  ( sizeof ( snponly_dev.dev.name ) - 1 ) );
-	snponly_dev.dev.parent = &rootdev->dev;
-	list_add ( &snponly_dev.dev.siblings, &rootdev->dev.children);
-	INIT_LIST_HEAD ( &snponly_dev.dev.children );
+	/* Check that this device is our loaded image's device */
+	if ( device != efi_loaded_image->DeviceHandle )
+		return -ENOTTY;
 
-	/* Create network device */
-	if ( ( rc = snpnet_probe ( &snponly_dev ) ) != 0 )
-		goto err;
+	DBGC ( device, "SNP %p %s is the SNP chainloading device\n",
+	       device, efi_handle_devpath_text ( device ) );
 
 	return 0;
-
-err:
-	list_del ( &snponly_dev.dev.siblings );
-	return rc;
-}
-
-/**
- * Remove SNP root bus
- *
- * @v rootdev		SNP bus root device
- */
-static void snpbus_remove ( struct root_device *rootdev __unused ) {
-	snpnet_remove ( &snponly_dev );
-	list_del ( &snponly_dev.dev.siblings );
-}
-
-/** SNP bus root device driver */
-static struct root_driver snp_root_driver = {
-	.probe = snpbus_probe,
-	.remove = snpbus_remove,
-};
-
-/** SNP bus root device */
-struct root_device snp_root_device __root_device = {
-	.dev = { .name = "EFI SNP" },
-	.driver = &snp_root_driver,
-};
-
-/**
- * Prepare for exit
- *
- * @v booting		System is shutting down for OS boot
- */
-static void snponly_shutdown ( int booting ) {
-	/* If we are shutting down to boot an OS, make sure the SNP does not
-	 * stay active.
-	 */
-	if ( booting )
-		snponly_dev.removal_state = EfiSimpleNetworkStopped;
 }
 
-struct startup_fn startup_snponly __startup_fn ( STARTUP_LATE ) = {
-	.shutdown = snponly_shutdown,
+/** EFI SNP driver */
+struct efi_driver snponly_driver __efi_driver ( EFI_DRIVER_NORMAL ) = {
+	.name = "SNPONLY",
+	.supported = snponly_supported,
+	.start = snpnet_start,
+	.stop = snpnet_stop,
 };