The patch below does not apply to the 4.9-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From cc0ba0d8624f210995924bb57a8b181ce8976606 Mon Sep 17 00:00:00 2001
From: Thomas Hellstrom thellstrom@vmware.com Date: Wed, 29 May 2019 08:15:19 +0200 Subject: [PATCH] drm/vmwgfx: Use the backdoor port if the HB port is not available
The HB port may not be available for various reasons. Either it has been disabled by a config option or by the hypervisor for other reasons. In that case, make sure we have a backup plan and use the backdoor port instead with a performance penalty.
Cc: stable@vger.kernel.org Fixes: 89da76fde68d ("drm/vmwgfx: Add VMWare host messaging capability") Signed-off-by: Thomas Hellstrom thellstrom@vmware.com Reviewed-by: Deepak Rawat drawat@vmware.com
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_msg.c b/drivers/gpu/drm/vmwgfx/vmwgfx_msg.c index 8b9270f31409..e4e09d47c5c0 100644 --- a/drivers/gpu/drm/vmwgfx/vmwgfx_msg.c +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_msg.c @@ -136,6 +136,114 @@ static int vmw_close_channel(struct rpc_channel *channel) return 0; }
+/** + * vmw_port_hb_out - Send the message payload either through the + * high-bandwidth port if available, or through the backdoor otherwise. + * @channel: The rpc channel. + * @msg: NULL-terminated message. + * @hb: Whether the high-bandwidth port is available. + * + * Return: The port status. + */ +static unsigned long vmw_port_hb_out(struct rpc_channel *channel, + const char *msg, bool hb) +{ + unsigned long si, di, eax, ebx, ecx, edx; + unsigned long msg_len = strlen(msg); + + if (hb) { + unsigned long bp = channel->cookie_high; + + si = (uintptr_t) msg; + di = channel->cookie_low; + + VMW_PORT_HB_OUT( + (MESSAGE_STATUS_SUCCESS << 16) | VMW_PORT_CMD_HB_MSG, + msg_len, si, di, + VMW_HYPERVISOR_HB_PORT | (channel->channel_id << 16), + VMW_HYPERVISOR_MAGIC, bp, + eax, ebx, ecx, edx, si, di); + + return ebx; + } + + /* HB port not available. Send the message 4 bytes at a time. */ + ecx = MESSAGE_STATUS_SUCCESS << 16; + while (msg_len && (HIGH_WORD(ecx) & MESSAGE_STATUS_SUCCESS)) { + unsigned int bytes = min_t(size_t, msg_len, 4); + unsigned long word = 0; + + memcpy(&word, msg, bytes); + msg_len -= bytes; + msg += bytes; + si = channel->cookie_high; + di = channel->cookie_low; + + VMW_PORT(VMW_PORT_CMD_MSG | (MSG_TYPE_SENDPAYLOAD << 16), + word, si, di, + VMW_HYPERVISOR_PORT | (channel->channel_id << 16), + VMW_HYPERVISOR_MAGIC, + eax, ebx, ecx, edx, si, di); + } + + return ecx; +} + +/** + * vmw_port_hb_in - Receive the message payload either through the + * high-bandwidth port if available, or through the backdoor otherwise. + * @channel: The rpc channel. + * @reply: Pointer to buffer holding reply. + * @reply_len: Length of the reply. + * @hb: Whether the high-bandwidth port is available. + * + * Return: The port status. + */ +static unsigned long vmw_port_hb_in(struct rpc_channel *channel, char *reply, + unsigned long reply_len, bool hb) +{ + unsigned long si, di, eax, ebx, ecx, edx; + + if (hb) { + unsigned long bp = channel->cookie_low; + + si = channel->cookie_high; + di = (uintptr_t) reply; + + VMW_PORT_HB_IN( + (MESSAGE_STATUS_SUCCESS << 16) | VMW_PORT_CMD_HB_MSG, + reply_len, si, di, + VMW_HYPERVISOR_HB_PORT | (channel->channel_id << 16), + VMW_HYPERVISOR_MAGIC, bp, + eax, ebx, ecx, edx, si, di); + + return ebx; + } + + /* HB port not available. Retrieve the message 4 bytes at a time. */ + ecx = MESSAGE_STATUS_SUCCESS << 16; + while (reply_len) { + unsigned int bytes = min_t(unsigned long, reply_len, 4); + + si = channel->cookie_high; + di = channel->cookie_low; + + VMW_PORT(VMW_PORT_CMD_MSG | (MSG_TYPE_RECVPAYLOAD << 16), + MESSAGE_STATUS_SUCCESS, si, di, + VMW_HYPERVISOR_PORT | (channel->channel_id << 16), + VMW_HYPERVISOR_MAGIC, + eax, ebx, ecx, edx, si, di); + + if ((HIGH_WORD(ecx) & MESSAGE_STATUS_SUCCESS) == 0) + break; + + memcpy(reply, &ebx, bytes); + reply_len -= bytes; + reply += bytes; + } + + return ecx; +}
/** @@ -148,11 +256,10 @@ static int vmw_close_channel(struct rpc_channel *channel) */ static int vmw_send_msg(struct rpc_channel *channel, const char *msg) { - unsigned long eax, ebx, ecx, edx, si, di, bp; + unsigned long eax, ebx, ecx, edx, si, di; size_t msg_len = strlen(msg); int retries = 0;
- while (retries < RETRIES) { retries++;
@@ -166,23 +273,14 @@ static int vmw_send_msg(struct rpc_channel *channel, const char *msg) VMW_HYPERVISOR_MAGIC, eax, ebx, ecx, edx, si, di);
- if ((HIGH_WORD(ecx) & MESSAGE_STATUS_SUCCESS) == 0 || - (HIGH_WORD(ecx) & MESSAGE_STATUS_HB) == 0) { - /* Expected success + high-bandwidth. Give up. */ + if ((HIGH_WORD(ecx) & MESSAGE_STATUS_SUCCESS) == 0) { + /* Expected success. Give up. */ return -EINVAL; }
/* Send msg */ - si = (uintptr_t) msg; - di = channel->cookie_low; - bp = channel->cookie_high; - - VMW_PORT_HB_OUT( - (MESSAGE_STATUS_SUCCESS << 16) | VMW_PORT_CMD_HB_MSG, - msg_len, si, di, - VMW_HYPERVISOR_HB_PORT | (channel->channel_id << 16), - VMW_HYPERVISOR_MAGIC, bp, - eax, ebx, ecx, edx, si, di); + ebx = vmw_port_hb_out(channel, msg, + !!(HIGH_WORD(ecx) & MESSAGE_STATUS_HB));
if ((HIGH_WORD(ebx) & MESSAGE_STATUS_SUCCESS) != 0) { return 0; @@ -211,7 +309,7 @@ STACK_FRAME_NON_STANDARD(vmw_send_msg); static int vmw_recv_msg(struct rpc_channel *channel, void **msg, size_t *msg_len) { - unsigned long eax, ebx, ecx, edx, si, di, bp; + unsigned long eax, ebx, ecx, edx, si, di; char *reply; size_t reply_len; int retries = 0; @@ -233,8 +331,7 @@ static int vmw_recv_msg(struct rpc_channel *channel, void **msg, VMW_HYPERVISOR_MAGIC, eax, ebx, ecx, edx, si, di);
- if ((HIGH_WORD(ecx) & MESSAGE_STATUS_SUCCESS) == 0 || - (HIGH_WORD(ecx) & MESSAGE_STATUS_HB) == 0) { + if ((HIGH_WORD(ecx) & MESSAGE_STATUS_SUCCESS) == 0) { DRM_ERROR("Failed to get reply size for host message.\n"); return -EINVAL; } @@ -252,17 +349,8 @@ static int vmw_recv_msg(struct rpc_channel *channel, void **msg,
/* Receive buffer */ - si = channel->cookie_high; - di = (uintptr_t) reply; - bp = channel->cookie_low; - - VMW_PORT_HB_IN( - (MESSAGE_STATUS_SUCCESS << 16) | VMW_PORT_CMD_HB_MSG, - reply_len, si, di, - VMW_HYPERVISOR_HB_PORT | (channel->channel_id << 16), - VMW_HYPERVISOR_MAGIC, bp, - eax, ebx, ecx, edx, si, di); - + ebx = vmw_port_hb_in(channel, reply, reply_len, + !!(HIGH_WORD(ecx) & MESSAGE_STATUS_HB)); if ((HIGH_WORD(ebx) & MESSAGE_STATUS_SUCCESS) == 0) { kfree(reply);