[efi] Allow EFI to control PCI bus enumeration

EFI performs its own PCI bus enumeration.  Respect this, and start
controlling devices only when instructed to do so by EFI.

As a side benefit, we should now correctly create multiple SNP
instances for multi-port devices.

This should also fix the problem of failing to enumerate devices
because the PCI bridges have not yet been enabled at the time the iPXE
driver is loaded.

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

1 files changed, 72 insertions, 285 deletions

diff --git a/src/interface/efi/efi_snp.c b/src/interface/efi/efi_snp.c
index 6bfa18884..669d18962 100644
--- a/src/interface/efi/efi_snp.c
+++ b/src/interface/efi/efi_snp.c
@@ -28,12 +28,11 @@ FILE_LICENCE ( GPL2_OR_LATER );
 #include <ipxe/in.h>
 #include <ipxe/pci.h>
 #include <ipxe/efi/efi.h>
-#include <ipxe/efi/Protocol/DriverBinding.h>
-#include <ipxe/efi/Protocol/PciIo.h>
+#include <ipxe/efi/efi_pci.h>
+#include <ipxe/efi/efi_driver.h>
 #include <ipxe/efi/Protocol/SimpleNetwork.h>
-#include <ipxe/efi/Protocol/ComponentName2.h>
 #include <ipxe/efi/Protocol/NetworkInterfaceIdentifier.h>
-#include <config/general.h>
+#include <ipxe/efi/Protocol/DevicePath.h>
 
 /** @file
  *
@@ -43,6 +42,8 @@ FILE_LICENCE ( GPL2_OR_LATER );
 
 /** An SNP device */
 struct efi_snp_device {
+	/** List of SNP devices */
+	struct list_head list;
 	/** The underlying iPXE network device */
 	struct net_device *netdev;
 	/** EFI device handle */
@@ -81,14 +82,6 @@ struct efi_snp_device {
 static EFI_GUID efi_simple_network_protocol_guid
 	= EFI_SIMPLE_NETWORK_PROTOCOL_GUID;
 
-/** EFI driver binding protocol GUID */
-static EFI_GUID efi_driver_binding_protocol_guid
-	= EFI_DRIVER_BINDING_PROTOCOL_GUID;
-
-/** EFI component name protocol GUID */
-static EFI_GUID efi_component_name2_protocol_guid
-	= EFI_COMPONENT_NAME2_PROTOCOL_GUID;
-
 /** EFI device path protocol GUID */
 static EFI_GUID efi_device_path_protocol_guid
 	= EFI_DEVICE_PATH_PROTOCOL_GUID;
@@ -107,9 +100,8 @@ static EFI_GUID efi_nii31_protocol_guid = {
 	{ 0xBC, 0x81, 0x76, 0x7F, 0x1F, 0x97, 0x7A, 0x89 }
 };
 
-/** EFI PCI I/O protocol GUID */
-static EFI_GUID efi_pci_io_protocol_guid
-	= EFI_PCI_IO_PROTOCOL_GUID;
+/** List of SNP devices */
+static LIST_HEAD ( efi_snp_devices );
 
 /**
  * Set EFI SNP mode based on iPXE net device parameters
@@ -750,188 +742,58 @@ static EFI_SIMPLE_NETWORK_PROTOCOL efi_snp_device_snp = {
 };
 
 /**
- * Locate net device corresponding to EFI device
- *
- * @v driver		EFI driver
- * @v device		EFI device
- * @ret netdev		Net device, or NULL if not found
- */
-static struct net_device *
-efi_snp_netdev ( EFI_DRIVER_BINDING_PROTOCOL *driver, EFI_HANDLE device ) {
-	EFI_BOOT_SERVICES *bs = efi_systab->BootServices;
-	union {
-		EFI_PCI_IO_PROTOCOL *pci;
-		void *interface;
-	} u;
-	UINTN pci_segment, pci_bus, pci_dev, pci_fn;
-	unsigned int pci_busdevfn;
-	struct net_device *netdev = NULL;
-	EFI_STATUS efirc;
-
-	/* See if device is a PCI device */
-	if ( ( efirc = bs->OpenProtocol ( device,
-					  &efi_pci_io_protocol_guid,
-					  &u.interface,
-					  driver->DriverBindingHandle,
-					  device,
-					  EFI_OPEN_PROTOCOL_BY_DRIVER )) !=0 ){
-		DBGCP ( driver, "SNPDRV %p device %p is not a PCI device\n",
-			driver, device );
-		goto out_no_pci_io;
-	}
-
-	/* Get PCI bus:dev.fn address */
-	if ( ( efirc = u.pci->GetLocation ( u.pci, &pci_segment, &pci_bus,
-					    &pci_dev, &pci_fn ) ) != 0 ) {
-		DBGC ( driver, "SNPDRV %p device %p could not get PCI "
-		       "location: %s\n",
-		       driver, device, efi_strerror ( efirc ) );
-		goto out_no_pci_location;
-	}
-	DBGCP ( driver, "SNPDRV %p device %p is PCI %04lx:%02lx:%02lx.%lx\n",
-		driver, device, ( ( unsigned long ) pci_segment ),
-		( ( unsigned long ) pci_bus ), ( ( unsigned long ) pci_dev ),
-		( ( unsigned long ) pci_fn ) );
-
-	/* Look up corresponding network device */
-	pci_busdevfn = PCI_BUSDEVFN ( pci_bus, pci_dev, pci_fn );
-	if ( ( netdev = find_netdev_by_location ( BUS_TYPE_PCI,
-						  pci_busdevfn ) ) == NULL ) {
-		DBGCP ( driver, "SNPDRV %p device %p is not a iPXE network "
-			"device\n", driver, device );
-		goto out_no_netdev;
-	}
-	DBGC ( driver, "SNPDRV %p device %p is %s\n",
-	       driver, device, netdev->name );
-
- out_no_netdev:
- out_no_pci_location:
-	bs->CloseProtocol ( device, &efi_pci_io_protocol_guid,
-			    driver->DriverBindingHandle, device );
- out_no_pci_io:
-	return netdev;
-}
-
-/**
- * Locate SNP corresponding to EFI device
+ * Locate SNP device corresponding to network device
  *
- * @v driver		EFI driver
- * @v device		EFI device
- * @ret snp		EFI SNP, or NULL if not found
+ * @v netdev		Network device
+ * @ret snp		SNP device, or NULL if not found
  */
-static struct efi_snp_device *
-efi_snp_snpdev ( EFI_DRIVER_BINDING_PROTOCOL *driver, EFI_HANDLE device ) {
-	EFI_BOOT_SERVICES *bs = efi_systab->BootServices;
-	union {
-		EFI_SIMPLE_NETWORK_PROTOCOL *snp;
-		void *interface;
-	} u;
-	struct efi_snp_device *snpdev = NULL;
-	EFI_STATUS efirc;
+static struct efi_snp_device * efi_snp_demux ( struct net_device *netdev ) {
+	struct efi_snp_device *snpdev;
 
-	if ( ( efirc = bs->OpenProtocol ( device,
-					  &efi_simple_network_protocol_guid,
-					  &u.interface,
-					  driver->DriverBindingHandle,
-					  device,
-					  EFI_OPEN_PROTOCOL_GET_PROTOCOL))!=0){
-		DBGC ( driver, "SNPDRV %p device %p could not locate SNP: "
-		       "%s\n", driver, device, efi_strerror ( efirc ) );
-		goto err_no_snp;
+	list_for_each_entry ( snpdev, &efi_snp_devices, list ) {
+		if ( snpdev->netdev == netdev )
+			return snpdev;
 	}
-
-	snpdev =  container_of ( u.snp, struct efi_snp_device, snp );
-	DBGCP ( driver, "SNPDRV %p device %p is SNPDEV %p\n",
-		driver, device, snpdev );
-
-	bs->CloseProtocol ( device, &efi_simple_network_protocol_guid,
-			    driver->DriverBindingHandle, device );
- err_no_snp:
-	return snpdev;
+	return NULL;
 }
 
 /**
- * Check to see if driver supports a device
+ * Create SNP device
  *
- * @v driver		EFI driver
- * @v device		EFI device
- * @v child		Path to child device, if any
- * @ret efirc		EFI status code
- */
-static EFI_STATUS EFIAPI
-efi_snp_driver_supported ( EFI_DRIVER_BINDING_PROTOCOL *driver,
-			   EFI_HANDLE device,
-			   EFI_DEVICE_PATH_PROTOCOL *child ) {
-	struct net_device *netdev;
-
-	DBGCP ( driver, "SNPDRV %p DRIVER_SUPPORTED %p (%p)\n",
-		driver, device, child );
-
-	netdev = efi_snp_netdev ( driver, device );
-	return ( netdev ? 0 : EFI_UNSUPPORTED );
-}
-
-/**
- * Attach driver to device
- *
- * @v driver		EFI driver
- * @v device		EFI device
- * @v child		Path to child device, if any
- * @ret efirc		EFI status code
+ * @v netdev		Network device
+ * @ret rc		Return status code
  */
-static EFI_STATUS EFIAPI
-efi_snp_driver_start ( EFI_DRIVER_BINDING_PROTOCOL *driver,
-		       EFI_HANDLE device,
-		       EFI_DEVICE_PATH_PROTOCOL *child ) {
+static int efi_snp_probe ( struct net_device *netdev ) {
 	EFI_BOOT_SERVICES *bs = efi_systab->BootServices;
-	EFI_DEVICE_PATH_PROTOCOL *path;
-	EFI_DEVICE_PATH_PROTOCOL *subpath;
-	MAC_ADDR_DEVICE_PATH *macpath;
+	struct efi_pci_device *efipci;
 	struct efi_snp_device *snpdev;
-	struct net_device *netdev;
-	size_t subpath_len;
+	EFI_DEVICE_PATH_PROTOCOL *path_end;
+	MAC_ADDR_DEVICE_PATH *macpath;
 	size_t path_prefix_len = 0;
 	unsigned int i;
 	EFI_STATUS efirc;
+	int rc;
 
-	DBGCP ( driver, "SNPDRV %p DRIVER_START %p (%p)\n",
-		driver, device, child );
-
-	/* Determine device path prefix length */
-	if ( ( efirc = bs->OpenProtocol ( device,
-					  &efi_device_path_protocol_guid,
-					  ( void * ) &path,
-					  driver->DriverBindingHandle,
-					  device,
-					  EFI_OPEN_PROTOCOL_BY_DRIVER )) !=0 ){
-		DBGCP ( driver, "SNPDRV %p device %p has no device path\n",
-			driver, device );
-		goto err_no_device_path;
-	}
-	subpath = path;
-	while ( subpath->Type != END_DEVICE_PATH_TYPE ) {
-		subpath_len = ( ( subpath->Length[1] << 8 ) |
-				subpath->Length[0] );
-		path_prefix_len += subpath_len;
-		subpath = ( ( ( void * ) subpath ) + subpath_len );
+	/* Find EFI PCI device */
+	efipci = efipci_find ( netdev->dev );
+	if ( ! efipci ) {
+		DBG ( "SNP skipping non-PCI device %s\n", netdev->name );
+		rc = 0;
+		goto err_no_pci;
 	}
 
+	/* Calculate device path prefix length */
+	path_end = efi_devpath_end ( efipci->path );
+	path_prefix_len = ( ( ( void * ) path_end ) -
+			    ( ( void * ) efipci->path ) );
+
 	/* Allocate the SNP device */
 	snpdev = zalloc ( sizeof ( *snpdev ) + path_prefix_len +
 			  sizeof ( *macpath ) );
 	if ( ! snpdev ) {
-		efirc = EFI_OUT_OF_RESOURCES;
+		rc = -ENOMEM;
 		goto err_alloc_snp;
 	}
-
-	/* Identify the net device */
-	netdev = efi_snp_netdev ( driver, device );
-	if ( ! netdev ) {
-		DBGC ( snpdev, "SNPDEV %p cannot find netdev for device %p\n",
-		       snpdev, device );
-		efirc = EFI_UNSUPPORTED;
-		goto err_no_netdev;
-	}
 	snpdev->netdev = netdev_get ( netdev );
 
 	/* Sanity check */
@@ -939,7 +801,7 @@ efi_snp_driver_start ( EFI_DRIVER_BINDING_PROTOCOL *driver,
 		DBGC ( snpdev, "SNPDEV %p cannot support link-layer address "
 		       "length %d for %s\n", snpdev,
 		       netdev->ll_protocol->ll_addr_len, netdev->name );
-		efirc = EFI_INVALID_PARAMETER;
+		rc = -ENOTSUP;
 		goto err_ll_addr_len;
 	}
 
@@ -951,6 +813,7 @@ efi_snp_driver_start ( EFI_DRIVER_BINDING_PROTOCOL *driver,
 					 &snpdev->snp.WaitForPacket ) ) != 0 ){
 		DBGC ( snpdev, "SNPDEV %p could not create event: %s\n",
 		       snpdev, efi_strerror ( efirc ) );
+		rc = EFIRC_TO_RC ( efirc );
 		goto err_create_event;
 	}
 
@@ -973,9 +836,9 @@ efi_snp_driver_start ( EFI_DRIVER_BINDING_PROTOCOL *driver,
 	}
 
 	/* Populate the device path */
-	memcpy ( &snpdev->path, path, path_prefix_len );
+	memcpy ( &snpdev->path, efipci->path, path_prefix_len );
 	macpath = ( ( ( void * ) &snpdev->path ) + path_prefix_len );
-	subpath = ( ( void * ) ( macpath + 1 ) );
+	path_end = ( ( void * ) ( macpath + 1 ) );
 	memset ( macpath, 0, sizeof ( *macpath ) );
 	macpath->Header.Type = MESSAGING_DEVICE_PATH;
 	macpath->Header.SubType = MSG_MAC_ADDR_DP;
@@ -983,10 +846,10 @@ efi_snp_driver_start ( EFI_DRIVER_BINDING_PROTOCOL *driver,
 	memcpy ( &macpath->MacAddress, netdev->ll_addr,
 		 sizeof ( macpath->MacAddress ) );
 	macpath->IfType = ntohs ( netdev->ll_protocol->ll_proto );
-	memset ( subpath, 0, sizeof ( *subpath ) );
-	subpath->Type = END_DEVICE_PATH_TYPE;
-	subpath->SubType = END_ENTIRE_DEVICE_PATH_SUBTYPE;
-	subpath->Length[0] = sizeof ( *subpath );
+	memset ( path_end, 0, sizeof ( *path_end ) );
+	path_end->Type = END_DEVICE_PATH_TYPE;
+	path_end->SubType = END_ENTIRE_DEVICE_PATH_SUBTYPE;
+	path_end->Length[0] = sizeof ( *path_end );
 
 	/* Install the SNP */
 	if ( ( efirc = bs->InstallMultipleProtocolInterfaces (
@@ -998,9 +861,13 @@ efi_snp_driver_start ( EFI_DRIVER_BINDING_PROTOCOL *driver,
 			NULL ) ) != 0 ) {
 		DBGC ( snpdev, "SNPDEV %p could not install protocols: "
 		       "%s\n", snpdev, efi_strerror ( efirc ) );
+		rc = EFIRC_TO_RC ( efirc );
 		goto err_install_protocol_interface;
 	}
 
+	/* Add to list of SNP devices */
+	list_add ( &snpdev->list, &efi_snp_devices );
+
 	DBGC ( snpdev, "SNPDEV %p installed for %s as device %p\n",
 	       snpdev, netdev->name, snpdev->handle );
 	return 0;
@@ -1017,44 +884,39 @@ efi_snp_driver_start ( EFI_DRIVER_BINDING_PROTOCOL *driver,
  err_create_event:
  err_ll_addr_len:
 	netdev_put ( netdev );
- err_no_netdev:
 	free ( snpdev );
  err_alloc_snp:
-	bs->CloseProtocol ( device, &efi_device_path_protocol_guid,
-			    driver->DriverBindingHandle, device );
- err_no_device_path:
-	return efirc;
+ err_no_pci:
+	return rc;
 }
 
 /**
- * Detach driver from device
+ * Handle SNP device or link state change
  *
- * @v driver		EFI driver
- * @v device		EFI device
- * @v num_children	Number of child devices
- * @v children		List of child devices
- * @ret efirc		EFI status code
+ * @v netdev		Network device
  */
-static EFI_STATUS EFIAPI
-efi_snp_driver_stop ( EFI_DRIVER_BINDING_PROTOCOL *driver,
-		      EFI_HANDLE device,
-		      UINTN num_children,
-		      EFI_HANDLE *children ) {
+static void efi_snp_notify ( struct net_device *netdev __unused ) {
+	/* Nothing to do */
+}
+
+/**
+ * Destroy SNP device
+ *
+ * @v netdev		Network device
+ */
+static void efi_snp_remove ( struct net_device *netdev ) {
 	EFI_BOOT_SERVICES *bs = efi_systab->BootServices;
 	struct efi_snp_device *snpdev;
 
-	DBGCP ( driver, "SNPDRV %p DRIVER_STOP %p (%ld %p)\n",
-		driver, device, ( ( unsigned long ) num_children ), children );
-
 	/* Locate SNP device */
-	snpdev = efi_snp_snpdev ( driver, device );
+	snpdev = efi_snp_demux ( netdev );
 	if ( ! snpdev ) {
-		DBGC ( driver, "SNPDRV %p device %p could not find SNPDEV\n",
-		       driver, device );
-		return EFI_DEVICE_ERROR;
+		DBG ( "SNP skipping non-SNP device %s\n", netdev->name );
+		return;
 	}
 
 	/* Uninstall the SNP */
+	list_del ( &snpdev->list );
 	bs->UninstallMultipleProtocolInterfaces (
 			snpdev->handle,
 			&efi_simple_network_protocol_guid, &snpdev->snp,
@@ -1065,87 +927,12 @@ efi_snp_driver_stop ( EFI_DRIVER_BINDING_PROTOCOL *driver,
 	bs->CloseEvent ( snpdev->snp.WaitForPacket );
 	netdev_put ( snpdev->netdev );
 	free ( snpdev );
-	bs->CloseProtocol ( device, &efi_device_path_protocol_guid,
-			    driver->DriverBindingHandle, device );
-	return 0;
 }
 
-/** EFI SNP driver binding */
-static EFI_DRIVER_BINDING_PROTOCOL efi_snp_binding = {
-	efi_snp_driver_supported,
-	efi_snp_driver_start,
-	efi_snp_driver_stop,
-	0x10,
-	NULL,
-	NULL
+/** SNP driver */
+struct net_driver efi_snp_driver __net_driver = {
+	.name = "SNP",
+	.probe = efi_snp_probe,
+	.notify = efi_snp_notify,
+	.remove = efi_snp_remove,
 };
-
-/**
- * Look up driver name
- *
- * @v wtf		Component name protocol
- * @v language		Language to use
- * @v driver_name	Driver name to fill in
- * @ret efirc		EFI status code
- */
-static EFI_STATUS EFIAPI
-efi_snp_get_driver_name ( EFI_COMPONENT_NAME2_PROTOCOL *wtf __unused,
-			  CHAR8 *language __unused, CHAR16 **driver_name ) {
-
-	*driver_name = L"" PRODUCT_SHORT_NAME " Driver";
-	return 0;
-}
-
-/**
- * Look up controller name
- *
- * @v wtf		Component name protocol
- * @v device		Device
- * @v child		Child device, or NULL
- * @v language		Language to use
- * @v driver_name	Device name to fill in
- * @ret efirc		EFI status code
- */
-static EFI_STATUS EFIAPI
-efi_snp_get_controller_name ( EFI_COMPONENT_NAME2_PROTOCOL *wtf __unused,
-			      EFI_HANDLE device __unused,
-			      EFI_HANDLE child __unused,
-			      CHAR8 *language __unused,
-			      CHAR16 **controller_name __unused ) {
-
-	/* Just let EFI use the default Device Path Name */
-	return EFI_UNSUPPORTED;
-}
-
-/** EFI SNP component name protocol */
-static EFI_COMPONENT_NAME2_PROTOCOL efi_snp_name = {
-	efi_snp_get_driver_name,
-	efi_snp_get_controller_name,
-	"en"
-};
-
-/**
- * Install EFI SNP driver
- *
- * @ret rc		Return status code
- */
-int efi_snp_install ( void ) {
-	EFI_BOOT_SERVICES *bs = efi_systab->BootServices;
-	EFI_DRIVER_BINDING_PROTOCOL *driver = &efi_snp_binding;
-	EFI_STATUS efirc;
-
-	driver->ImageHandle = efi_image_handle;
-	if ( ( efirc = bs->InstallMultipleProtocolInterfaces (
-			&driver->DriverBindingHandle,
-			&efi_driver_binding_protocol_guid, driver,
-			&efi_component_name2_protocol_guid, &efi_snp_name,
-			NULL ) ) != 0 ) {
-		DBGC ( driver, "SNPDRV %p could not install protocols: "
-		       "%s\n", driver, efi_strerror ( efirc ) );
-		return EFIRC_TO_RC ( efirc );
-	}
-
-	DBGC ( driver, "SNPDRV %p driver binding installed as %p\n",
-	       driver, driver->DriverBindingHandle );
-	return 0;
-}