CPU read/write reg: use generic IHK messaging interface

Change-Id: Ia9637d1516d9329fdadf37822bfce7594d69105f

arch/arm64/kernel/cpu.c

@@ -1880,6 +1880,11 @@ int arch_cpu_read_write_register(
 		ret = -1;
 	}
 
+	dkprintf("%s: MCCTRL_OS_CPU_%s_REGISTER: reg: 0x%lx, val: 0x%lx\n",
+			__FUNCTION__,
+			(op == MCCTRL_OS_CPU_READ_REGISTER ? "READ" : "WRITE"),
+			desc->addr, desc->val);
+
 	return ret;
 }
 

executer/kernel/mcctrl/control.c

@@ -3399,14 +3399,6 @@ long __mcctrl_control(ihk_os_t os, unsigned int req, unsigned long arg,
 	return -EINVAL;
 }
 
-/* Per-CPU register manipulation functions */
-struct mcctrl_os_cpu_response {
-	int done;
-	unsigned long val;
-	int err;
-	wait_queue_head_t wq;
-};
-
 int mcctrl_get_request_os_cpu(ihk_os_t os, int *ret_cpu)
 {
 	struct mcctrl_usrdata *usrdata;
@@ -3470,31 +3462,14 @@ out_put_ppd:
 	return ret;
 }
 
-void mcctrl_os_read_write_cpu_response(ihk_os_t os,
-		struct ikc_scd_packet *pisp)
-{
-	struct mcctrl_os_cpu_response *resp;
-
-	/* XXX: What if caller thread is unblocked by a signal
-	 * before this message arrives? */
-	resp = pisp->resp;
-	if (!resp) {
-		return;
-	}
-
-	resp->val = pisp->desc.val;
-	resp->done = 1;
-	resp->err = pisp->err;
-	wake_up_interruptible(&resp->wq);
-}
-
 int __mcctrl_os_read_write_cpu_register(ihk_os_t os, int cpu,
 		struct ihk_os_cpu_register *desc,
 		enum mcctrl_os_cpu_operation op)
 {
 	struct mcctrl_usrdata *udp = ihk_host_os_get_usrdata(os);
 	struct ikc_scd_packet isp;
-	struct mcctrl_os_cpu_response resp;
+	struct ihk_os_cpu_register *ldesc = NULL;
+	int do_free = 0;
 	int ret = -EINVAL;
 
 	if (!udp) {
@@ -3511,50 +3486,43 @@ int __mcctrl_os_read_write_cpu_register(ihk_os_t os, int cpu,
 
 	}
 
+	/* Keep a dynamic structure around that can
+	 * survive an early return due to a signal */
+	ldesc = kmalloc(sizeof(*ldesc), GFP_KERNEL);
+	if (!ldesc) {
+		printk("%s: ERROR: allocating cpu register desc\n", __FUNCTION__);
+		return -ENOMEM;
+	}
+	*ldesc = *desc;
+
 	memset(&isp, '\0', sizeof(struct ikc_scd_packet));
 	isp.msg = SCD_MSG_CPU_RW_REG;
 	isp.op = op;
-	isp.desc = *desc;
+	isp.pdesc = virt_to_phys(ldesc);
-	isp.resp = &resp;
 
-	resp.done = 0;
+	ret = mcctrl_ikc_send_wait(os, cpu, &isp, 0, NULL, &do_free, 1, ldesc);
-	resp.err = 0;
+	if (ret != 0) {
-	init_waitqueue_head(&resp.wq);
-
-	mb();
-	ret = mcctrl_ikc_send(os, cpu, &isp);
-	if (ret < 0) {
 		printk("%s: ERROR sending IKC msg: %d\n", __FUNCTION__, ret);
 		goto out;
 	}
 
-	/* Wait for response */
-	ret = wait_event_interruptible(resp.wq, resp.done);
-	if (ret < 0) {
-		printk("%s: ERROR after wait: %d\n", __FUNCTION__, ret);
-		goto out;
-	}
-
-	ret = resp.err;
-	if (ret != 0) {
-		printk("%s: ERROR receive: %d\n", __FUNCTION__, resp.err);
-		goto out;
-	}
-
 	/* Update if read */
-	if (ret == 0 && op == MCCTRL_OS_CPU_READ_REGISTER) {
+	if (op == MCCTRL_OS_CPU_READ_REGISTER) {
-		desc->val = resp.val;
+		desc->val = ldesc->val;
 	}
 
 	/* Notify caller (for future async implementation) */
 	atomic_set(&desc->sync, 1);
 
-	dprintk("%s: MCCTRL_OS_CPU_%s_REGISTER: reg: 0x%lx, val: 0x%lx\n",
+	dprintk("%s: MCCTRL_OS_CPU_%s_REGISTER: CPU: %d, addr_ext: 0x%lx, val: 0x%lx\n",
 		__FUNCTION__,
-		(op == MCCTRL_OS_CPU_READ_REGISTER ? "READ" : "WRITE"),
+		(op == MCCTRL_OS_CPU_READ_REGISTER ? "READ" : "WRITE"), cpu,
-		desc->addr, desc->val);
+		desc->addr_ext, desc->val);
 
 out:
+	if (do_free) {
+		kfree(ldesc);
+	}
 	return ret;
 }
 

executer/kernel/mcctrl/ikc.c

@@ -209,6 +209,7 @@ static int syscall_packet_handler(struct ihk_ikc_channel_desc *c,
 	case SCD_MSG_SEND_SIGNAL_ACK:
 	case SCD_MSG_PROCFS_ANSWER:
 	case SCD_MSG_REMOTE_PAGE_FAULT_ANSWER:
+	case SCD_MSG_CPU_RW_REG_RESP:
 		mcctrl_wakeup_cb(__os, pisp);
 		break;
 
@@ -239,10 +240,6 @@ static int syscall_packet_handler(struct ihk_ikc_channel_desc *c,
 		get_vdso_info(__os, pisp->arg);
 		break;
 
-	case SCD_MSG_CPU_RW_REG_RESP:
-		mcctrl_os_read_write_cpu_response(__os, pisp);
-		break;
-
 	case SCD_MSG_EVENTFD:
 		dkprintf("%s: SCD_MSG_EVENTFD,pisp->eventfd_type=%d\n", __FUNCTION__, pisp->eventfd_type);
 		mcctrl_eventfd(__os, pisp);

executer/kernel/mcctrl/mcctrl.h

@@ -154,7 +154,7 @@ struct ikc_scd_packet {
 
 		/* SCD_MSG_CPU_RW_REG */
 		struct {
-			struct ihk_os_cpu_register desc;
+			unsigned long pdesc; /* Physical addr of the descriptor */
 			enum mcctrl_os_cpu_operation op;
 			void *resp;
 		};

kernel/host.c

@@ -619,6 +619,7 @@ static int syscall_packet_handler(struct ihk_ikc_channel_desc *c,
 {
 	struct ikc_scd_packet *packet = __packet;
 	struct ikc_scd_packet pckt;
+	struct ihk_os_cpu_register *cpu_desc;
 	struct ihk_ikc_channel_desc *resp_channel = cpu_local_var(ikc2linux);
 	int rc;
 	struct thread *thread;
@@ -839,12 +840,17 @@ out_remote_pf:
 		break;
 
 	case SCD_MSG_CPU_RW_REG:
+		pp = ihk_mc_map_memory(NULL, packet->pdesc,
+				sizeof(struct ihk_os_cpu_register));
+		cpu_desc = (struct ihk_os_cpu_register *)ihk_mc_map_virtual(
+				pp, 1, PTATTR_WRITABLE | PTATTR_ACTIVE);
 
 		pckt.msg = SCD_MSG_CPU_RW_REG_RESP;
-		memcpy(&pckt.desc, &packet->desc,
+		pckt.reply = packet->reply;
-				sizeof(struct ihk_os_cpu_register));
+		pckt.err = arch_cpu_read_write_register(cpu_desc, packet->op);
-		pckt.resp = packet->resp;
+
-		pckt.err = arch_cpu_read_write_register(&pckt.desc, packet->op);
+		ihk_mc_unmap_virtual(cpu_desc, 1);
+		ihk_mc_unmap_memory(NULL, pp, sizeof(struct ihk_os_cpu_register));
 
 		ihk_ikc_send(resp_channel, &pckt, 0);
 		break;

kernel/include/syscall.h

@@ -287,7 +287,7 @@ struct ikc_scd_packet {
 
 		/* SCD_MSG_CPU_RW_REG */
 		struct {
-			struct ihk_os_cpu_register desc;
+			unsigned long pdesc; /* Physical addr of the descriptor */
 			enum mcctrl_os_cpu_operation op;
 			void *resp;
 		};