Commit cc0ba0d8 authored by Thomas Hellstrom's avatar Thomas Hellstrom
Browse files

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: 89da76fd ("drm/vmwgfx: Add VMWare host messaging capability")
Signed-off-by: default avatarThomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: default avatarDeepak Rawat <drawat@vmware.com>
parent 5ed7f4b5

drivers/gpu/drm/vmwgfx/vmwgfx_msg.c

+117 −29
Original line number Diff line number Diff line
@@ -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);

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