From bedc61a922f9dbbe3bfb26ec2745f8cd63b57637 Mon Sep 17 00:00:00 2001 From: Andrea Parri Date: Tue, 15 Oct 2019 13:46:44 +0200 Subject: Drivers: hv: vmbus: Introduce table of VMBus protocol versions The technique used to get the next VMBus version seems increasisly clumsy as the number of VMBus versions increases. Performance is not a concern since this is only done once during system boot; it's just that we'll end up with more lines of code than is really needed. As an alternative, introduce a table with the version numbers listed in order (from the most recent to the oldest). vmbus_connect() loops through the versions listed in the table until it gets an accepted connection or gets to the end of the table (invalid version). Suggested-by: Michael Kelley Signed-off-by: Andrea Parri Reviewed-by: Wei Liu Reviewed-by: Michael Kelley Signed-off-by: Sasha Levin --- drivers/hv/connection.c | 50 ++++++++++++++++++------------------------------- drivers/hv/vmbus_drv.c | 3 +-- 2 files changed, 19 insertions(+), 34 deletions(-) (limited to 'drivers/hv') diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c index 6e4c015783ff..8dc48f53c1ac 100644 --- a/drivers/hv/connection.c +++ b/drivers/hv/connection.c @@ -40,29 +40,17 @@ EXPORT_SYMBOL_GPL(vmbus_connection); __u32 vmbus_proto_version; EXPORT_SYMBOL_GPL(vmbus_proto_version); -static __u32 vmbus_get_next_version(__u32 current_version) -{ - switch (current_version) { - case (VERSION_WIN7): - return VERSION_WS2008; - - case (VERSION_WIN8): - return VERSION_WIN7; - - case (VERSION_WIN8_1): - return VERSION_WIN8; - - case (VERSION_WIN10): - return VERSION_WIN8_1; - - case (VERSION_WIN10_V5): - return VERSION_WIN10; - - case (VERSION_WS2008): - default: - return VERSION_INVAL; - } -} +/* + * Table of VMBus versions listed from newest to oldest. + */ +static __u32 vmbus_versions[] = { + VERSION_WIN10_V5, + VERSION_WIN10, + VERSION_WIN8_1, + VERSION_WIN8, + VERSION_WIN7, + VERSION_WS2008 +}; int vmbus_negotiate_version(struct vmbus_channel_msginfo *msginfo, u32 version) { @@ -169,8 +157,8 @@ int vmbus_negotiate_version(struct vmbus_channel_msginfo *msginfo, u32 version) */ int vmbus_connect(void) { - int ret = 0; struct vmbus_channel_msginfo *msginfo = NULL; + int i, ret = 0; __u32 version; /* Initialize the vmbus connection */ @@ -244,21 +232,19 @@ int vmbus_connect(void) * version. */ - version = VERSION_CURRENT; + for (i = 0; ; i++) { + if (i == ARRAY_SIZE(vmbus_versions)) + goto cleanup; + + version = vmbus_versions[i]; - do { ret = vmbus_negotiate_version(msginfo, version); if (ret == -ETIMEDOUT) goto cleanup; if (vmbus_connection.conn_state == CONNECTED) break; - - version = vmbus_get_next_version(version); - } while (version != VERSION_INVAL); - - if (version == VERSION_INVAL) - goto cleanup; + } vmbus_proto_version = version; pr_info("Vmbus version:%d.%d\n", diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c index 53a60c81e220..0ac874faf720 100644 --- a/drivers/hv/vmbus_drv.c +++ b/drivers/hv/vmbus_drv.c @@ -2220,8 +2220,7 @@ static int vmbus_bus_resume(struct device *dev) * We only use the 'vmbus_proto_version', which was in use before * hibernation, to re-negotiate with the host. */ - if (vmbus_proto_version == VERSION_INVAL || - vmbus_proto_version == 0) { + if (!vmbus_proto_version) { pr_err("Invalid proto version = 0x%x\n", vmbus_proto_version); return -EINVAL; } -- cgit v1.2.3-59-g8ed1b