[init] Remove concept of "shutdown exit flags"

Remove the concept of shutdown exit flags, and replace it with a
counter used to keep track of exposed interfaces that require devices
to remain active.

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

17 files changed, 64 insertions, 37 deletions

diff --git a/src/arch/i386/drivers/net/undionly.c b/src/arch/i386/drivers/net/undionly.c
index ab9c61fb1..c38b574db 100644
--- a/src/arch/i386/drivers/net/undionly.c
+++ b/src/arch/i386/drivers/net/undionly.c
@@ -114,13 +114,13 @@ struct root_device undi_root_device __root_device = {
 /**
  * Prepare for exit
  *
- * @v flags		Shutdown flags
+ * @v booting		System is shutting down for OS boot
  */
-static void undionly_shutdown ( int flags ) {
+static void undionly_shutdown ( int booting ) {
 	/* If we are shutting down to boot an OS, clear the "keep PXE
 	 * stack" flag.
 	 */
-	if ( flags & SHUTDOWN_BOOT )
+	if ( booting )
 		preloaded_undi.flags &= ~UNDI_FL_KEEP_ALL;
 }
 
diff --git a/src/arch/i386/image/bzimage.c b/src/arch/i386/image/bzimage.c
index 900e34e1a..45a1e8620 100644
--- a/src/arch/i386/image/bzimage.c
+++ b/src/arch/i386/image/bzimage.c
@@ -477,7 +477,7 @@ static int bzimage_exec ( struct image *image ) {
 	bzimage_update_header ( image, &bzimg, bzimg.rm_kernel );
 
 	/* Prepare for exiting */
-	shutdown ( SHUTDOWN_BOOT );
+	shutdown_boot();
 
 	DBGC ( image, "bzImage %p jumping to RM kernel at %04x:0000 "
 	       "(stack %04x:%04zx)\n", image, ( bzimg.rm_kernel_seg + 0x20 ),
diff --git a/src/arch/i386/image/elfboot.c b/src/arch/i386/image/elfboot.c
index 7cb51bf9a..331d3764c 100644
--- a/src/arch/i386/image/elfboot.c
+++ b/src/arch/i386/image/elfboot.c
@@ -48,7 +48,7 @@ static int elfboot_exec ( struct image *image ) {
 	/* An ELF image has no callback interface, so we need to shut
 	 * down before invoking it.
 	 */
-	shutdown ( SHUTDOWN_BOOT );
+	shutdown_boot();
 
 	/* Jump to OS with flat physical addressing */
 	DBGC ( image, "ELF %p starting execution at %lx\n", image, entry );
diff --git a/src/arch/i386/image/multiboot.c b/src/arch/i386/image/multiboot.c
index 041f0f2ae..3ed4d8407 100644
--- a/src/arch/i386/image/multiboot.c
+++ b/src/arch/i386/image/multiboot.c
@@ -278,7 +278,7 @@ static int multiboot_exec ( struct image *image ) {
 	/* Multiboot images may not return and have no callback
 	 * interface, so shut everything down prior to booting the OS.
 	 */
-	shutdown ( SHUTDOWN_BOOT );
+	shutdown_boot();
 
 	/* Build memory map after unhiding bootloader memory regions as part of
 	 * shutting everything down.
diff --git a/src/arch/i386/image/nbi.c b/src/arch/i386/image/nbi.c
index 67f0d5111..804b23037 100644
--- a/src/arch/i386/image/nbi.c
+++ b/src/arch/i386/image/nbi.c
@@ -406,7 +406,7 @@ static int nbi_exec ( struct image *image ) {
 	/* Shut down now if NBI image will not return */
 	may_return = NBI_PROGRAM_RETURNS ( imgheader.flags );
 	if ( ! may_return )
-		shutdown ( SHUTDOWN_BOOT );
+		shutdown_boot();
 
 	/* Execute NBI image */
 	if ( NBI_LINEAR_EXEC_ADDR ( imgheader.flags ) ) {
diff --git a/src/arch/i386/interface/pcbios/int13.c b/src/arch/i386/interface/pcbios/int13.c
index 1d973e778..a27dbad7a 100644
--- a/src/arch/i386/interface/pcbios/int13.c
+++ b/src/arch/i386/interface/pcbios/int13.c
@@ -1209,8 +1209,10 @@ static int int13_hook ( struct uri *uri, unsigned int drive ) {
 	       int13->cylinders, int13->heads, int13->sectors_per_track );
 
 	/* Hook INT 13 vector if not already hooked */
-	if ( list_empty ( &int13s ) )
+	if ( list_empty ( &int13s ) ) {
 		int13_hook_vector();
+		devices_get();
+	}
 
 	/* Add to list of emulated drives */
 	list_add ( &int13->list, &int13s );
@@ -1277,8 +1279,10 @@ static void int13_unhook ( unsigned int drive ) {
 	DBGC ( int13, "INT13 drive %02x unregistered\n", int13->drive );
 
 	/* Unhook INT 13 vector if no more drives */
-	if ( list_empty ( &int13s ) )
+	if ( list_empty ( &int13s ) ) {
+		devices_put();
 		int13_unhook_vector();
+	}
 
 	/* Drop list's reference to drive */
 	ref_put ( &int13->refcnt );
diff --git a/src/arch/i386/interface/pxe/pxe_call.c b/src/arch/i386/interface/pxe/pxe_call.c
index f6324bbf6..f32080006 100644
--- a/src/arch/i386/interface/pxe/pxe_call.c
+++ b/src/arch/i386/interface/pxe/pxe_call.c
@@ -448,6 +448,7 @@ void pxe_activate ( struct net_device *netdev ) {
 	if ( ! int_1a_hooked ) {
 		hook_bios_interrupt ( 0x1a, ( unsigned int ) pxe_int_1a,
 				      &pxe_int_1a_vector );
+		devices_get();
 		int_1a_hooked = 1;
 	}
 
@@ -475,6 +476,7 @@ int pxe_deactivate ( void ) {
 			      strerror ( rc ) );
 			return rc;
 		}
+		devices_put();
 		int_1a_hooked = 0;
 	}
 
diff --git a/src/arch/i386/interface/pxe/pxe_preboot.c b/src/arch/i386/interface/pxe/pxe_preboot.c
index 7698df528..9e4853b01 100644
--- a/src/arch/i386/interface/pxe/pxe_preboot.c
+++ b/src/arch/i386/interface/pxe/pxe_preboot.c
@@ -290,7 +290,7 @@ PXENV_EXIT_t pxenv_stop_undi ( struct s_PXENV_STOP_UNDI *stop_undi ) {
 	pxe_deactivate();
 
 	/* Prepare for unload */
-	shutdown ( SHUTDOWN_BOOT );
+	shutdown_boot();
 
 	/* Check to see if we still have any hooked interrupts */
 	if ( hooked_bios_interrupts != 0 ) {
diff --git a/src/arch/i386/interface/syslinux/comboot_call.c b/src/arch/i386/interface/syslinux/comboot_call.c
index 0c52b28a8..950832702 100644
--- a/src/arch/i386/interface/syslinux/comboot_call.c
+++ b/src/arch/i386/interface/syslinux/comboot_call.c
@@ -531,7 +531,7 @@ static __asmcall void int22 ( struct i386_all_regs *ix86 ) {
 			break;
 
 		/* Perform final cleanup */
-		shutdown ( SHUTDOWN_BOOT );
+		shutdown_boot();
 
 		/* Perform sequence of copies */
 		shuffle ( ix86->segs.es, ix86->regs.di, ix86->regs.cx );
@@ -608,7 +608,7 @@ static __asmcall void int22 ( struct i386_all_regs *ix86 ) {
 			break;
 
 		/* Perform final cleanup */
-		shutdown ( SHUTDOWN_BOOT );
+		shutdown_boot();
 
 		/* Perform sequence of copies */
 		shuffle ( ix86->segs.es, ix86->regs.di, ix86->regs.cx );
diff --git a/src/core/device.c b/src/core/device.c
index cb2c23b0a..dc182e032 100644
--- a/src/core/device.c
+++ b/src/core/device.c
@@ -35,6 +35,9 @@ FILE_LICENCE ( GPL2_OR_LATER );
 /** Registered root devices */
 static LIST_HEAD ( devices );
 
+/** Device removal inhibition counter */
+int device_keep_count = 0;
+
 /**
  * Probe a root device
  *
@@ -87,11 +90,11 @@ static void probe_devices ( void ) {
  * Remove all devices
  *
  */
-static void remove_devices ( int flags ) {
+static void remove_devices ( int booting __unused ) {
 	struct root_device *rootdev;
 	struct root_device *tmp;
 
-	if ( flags & SHUTDOWN_KEEP_DEVICES ) {
+	if ( device_keep_count != 0 ) {
 		DBG ( "Refusing to remove devices on shutdown\n" );
 		return;
 	}
diff --git a/src/core/main.c b/src/core/main.c
index a1128dd02..e2b4e3e2e 100644
--- a/src/core/main.c
+++ b/src/core/main.c
@@ -85,7 +85,7 @@ __asmcall int main ( void ) {
 			shell();
 	}
 
-	shutdown ( SHUTDOWN_EXIT | shutdown_exit_flags );
+	shutdown_exit();
 
 	return 0;
 }
diff --git a/src/drivers/net/efi/snponly.c b/src/drivers/net/efi/snponly.c
index 435ed4fb5..6fcc54a01 100644
--- a/src/drivers/net/efi/snponly.c
+++ b/src/drivers/net/efi/snponly.c
@@ -114,13 +114,13 @@ struct root_device snp_root_device __root_device = {
 /**
  * Prepare for exit
  *
- * @v flags		Shutdown flags
+ * @v booting		System is shutting down for OS boot
  */
-static void snponly_shutdown ( int flags ) {
+static void snponly_shutdown ( int booting ) {
 	/* If we are shutting down to boot an OS, make sure the SNP does not
 	 * stay active.
 	 */
-	if ( flags & SHUTDOWN_BOOT )
+	if ( booting )
 		snponly_dev.removal_state = EfiSimpleNetworkStopped;
 }
 
diff --git a/src/image/efi_image.c b/src/image/efi_image.c
index 6b6600de8..bf2e6f4af 100644
--- a/src/image/efi_image.c
+++ b/src/image/efi_image.c
@@ -39,7 +39,7 @@ static EFI_EVENT efi_shutdown_event;
  */
 static EFIAPI void efi_shutdown_hook ( EFI_EVENT event __unused,
 				       void *context __unused ) {
-	shutdown ( SHUTDOWN_BOOT );
+	shutdown_boot();
 }
 
 /**
diff --git a/src/include/ipxe/device.h b/src/include/ipxe/device.h
index 068268ba4..635ce59cc 100644
--- a/src/include/ipxe/device.h
+++ b/src/include/ipxe/device.h
@@ -112,6 +112,24 @@ struct root_driver {
 /** Declare a root device */
 #define __root_device __table_entry ( ROOT_DEVICES, 01 )
 
+extern int device_keep_count;
+
+/**
+ * Prevent devices from being removed on shutdown
+ *
+ */
+static inline void devices_get ( void ) {
+	device_keep_count++;
+}
+
+/**
+ * Allow devices to be removed on shutdown
+ *
+ */
+static inline void devices_put ( void ) {
+	device_keep_count--;
+}
+
 extern struct device * identify_device ( struct interface *intf );
 #define identify_device_TYPE( object_type ) \
 	typeof ( struct device * ( object_type ) )
diff --git a/src/include/ipxe/init.h b/src/include/ipxe/init.h
index 10ff8695d..954cda453 100644
--- a/src/include/ipxe/init.h
+++ b/src/include/ipxe/init.h
@@ -32,16 +32,6 @@ struct init_fn {
 
 /** @} */
 
-/** Shutdown flags */
-enum shutdown_flags {
-	/** Shutdown is in order to exit (return to iPXE's caller) */
-	SHUTDOWN_EXIT = 0x0001,
-	/** Shutdown is in order to boot an OS */
-	SHUTDOWN_BOOT = 0x0002,
-	/** Do not remove devices */
-	SHUTDOWN_KEEP_DEVICES = 0x0004,
-};
-
 /**
  * A startup/shutdown function
  *
@@ -50,7 +40,7 @@ enum shutdown_flags {
  */
 struct startup_fn {
 	void ( * startup ) ( void );
-	void ( * shutdown ) ( int flags );
+	void ( * shutdown ) ( int booting );
 };
 
 /** Startup/shutdown function table */
@@ -76,6 +66,22 @@ struct startup_fn {
 
 extern void initialise ( void );
 extern void startup ( void );
-extern void shutdown ( int flags );
+extern void shutdown ( int booting );
+
+/**
+ * Shut down system for OS boot
+ *
+ */
+static inline void shutdown_boot ( void ) {
+	shutdown ( 1 );
+}
+
+/**
+ * Shut down system for exit back to firmware
+ *
+ */
+static inline void shutdown_exit ( void ) {
+	shutdown ( 0 );
+}
 
 #endif /* _IPXE_INIT_H */
diff --git a/src/include/usr/autoboot.h b/src/include/usr/autoboot.h
index e9abf833f..32763beee 100644
--- a/src/include/usr/autoboot.h
+++ b/src/include/usr/autoboot.h
@@ -12,8 +12,6 @@ FILE_LICENCE ( GPL2_OR_LATER );
 #include <ipxe/in.h>
 struct net_device;
 
-extern int shutdown_exit_flags;
-
 extern int netboot ( struct net_device *netdev );
 extern int autoboot ( void );
 extern int boot_next_server_and_filename ( struct in_addr next_server,
diff --git a/src/usr/autoboot.c b/src/usr/autoboot.c
index 738c3ceaa..df152e3ac 100644
--- a/src/usr/autoboot.c
+++ b/src/usr/autoboot.c
@@ -40,9 +40,6 @@ FILE_LICENCE ( GPL2_OR_LATER );
  *
  */
 
-/** Shutdown flags for exit */
-int shutdown_exit_flags = 0;
-
 /**
  * Perform PXE menu boot when PXE stack is not available
  */
@@ -193,7 +190,6 @@ int boot_root_path ( const char *root_path ) {
 	if ( fetch_intz_setting ( NULL, &keep_san_setting ) != 0 ) {
 		printf ( "Preserving connection to SAN device %#02x\n",
 			 drive );
-		shutdown_exit_flags |= SHUTDOWN_KEEP_DEVICES;
 		goto err_keep_san;
 	}