From 1eae9639aac0f8de4d284f567ec722a822b52513 Mon Sep 17 00:00:00 2001
From: André Fabian Silva Delgado <emulatorman@parabola.nu>
Date: Tue, 1 Nov 2016 14:27:38 -0300
Subject: Linux-libre 4.8.6-gnu

---
 drivers/misc/cxl/api.c        |  9 +++++++++
 drivers/misc/cxl/context.c    |  3 +++
 drivers/misc/cxl/cxl.h        | 24 ++++++++++++++++++++++++
 drivers/misc/cxl/file.c       | 11 +++++++++++
 drivers/misc/cxl/guest.c      |  3 +++
 drivers/misc/cxl/main.c       | 42 +++++++++++++++++++++++++++++++++++++++++-
 drivers/misc/cxl/pci.c        |  2 ++
 drivers/misc/cxl/sysfs.c      | 27 +++++++++++++++++++++++----
 drivers/misc/mei/amthif.c     |  2 +-
 drivers/misc/mei/bus.c        |  2 +-
 drivers/misc/mei/hw-me-regs.h |  3 +++
 drivers/misc/mei/main.c       |  2 +-
 drivers/misc/mei/pci-me.c     |  3 +++
 13 files changed, 125 insertions(+), 8 deletions(-)

(limited to 'drivers/misc')

diff --git a/drivers/misc/cxl/api.c b/drivers/misc/cxl/api.c
index f3d34b941..af23d7dfe 100644
--- a/drivers/misc/cxl/api.c
+++ b/drivers/misc/cxl/api.c
@@ -229,6 +229,14 @@ int cxl_start_context(struct cxl_context *ctx, u64 wed,
 	if (ctx->status == STARTED)
 		goto out; /* already started */
 
+	/*
+	 * Increment the mapped context count for adapter. This also checks
+	 * if adapter_context_lock is taken.
+	 */
+	rc = cxl_adapter_context_get(ctx->afu->adapter);
+	if (rc)
+		goto out;
+
 	if (task) {
 		ctx->pid = get_task_pid(task, PIDTYPE_PID);
 		ctx->glpid = get_task_pid(task->group_leader, PIDTYPE_PID);
@@ -240,6 +248,7 @@ int cxl_start_context(struct cxl_context *ctx, u64 wed,
 
 	if ((rc = cxl_ops->attach_process(ctx, kernel, wed, 0))) {
 		put_pid(ctx->pid);
+		cxl_adapter_context_put(ctx->afu->adapter);
 		cxl_ctx_put();
 		goto out;
 	}
diff --git a/drivers/misc/cxl/context.c b/drivers/misc/cxl/context.c
index c466ee2b0..5e506c191 100644
--- a/drivers/misc/cxl/context.c
+++ b/drivers/misc/cxl/context.c
@@ -238,6 +238,9 @@ int __detach_context(struct cxl_context *ctx)
 	put_pid(ctx->glpid);
 
 	cxl_ctx_put();
+
+	/* Decrease the attached context count on the adapter */
+	cxl_adapter_context_put(ctx->afu->adapter);
 	return 0;
 }
 
diff --git a/drivers/misc/cxl/cxl.h b/drivers/misc/cxl/cxl.h
index 344a0ff8f..19aa2aca9 100644
--- a/drivers/misc/cxl/cxl.h
+++ b/drivers/misc/cxl/cxl.h
@@ -615,6 +615,14 @@ struct cxl {
 	bool perst_select_user;
 	bool perst_same_image;
 	bool psl_timebase_synced;
+
+	/*
+	 * number of contexts mapped on to this card. Possible values are:
+	 * >0: Number of contexts mapped and new one can be mapped.
+	 *  0: No active contexts and new ones can be mapped.
+	 * -1: No contexts mapped and new ones cannot be mapped.
+	 */
+	atomic_t contexts_num;
 };
 
 int cxl_pci_alloc_one_irq(struct cxl *adapter);
@@ -940,4 +948,20 @@ bool cxl_pci_is_vphb_device(struct pci_dev *dev);
 
 /* decode AFU error bits in the PSL register PSL_SERR_An */
 void cxl_afu_decode_psl_serr(struct cxl_afu *afu, u64 serr);
+
+/*
+ * Increments the number of attached contexts on an adapter.
+ * In case an adapter_context_lock is taken the return -EBUSY.
+ */
+int cxl_adapter_context_get(struct cxl *adapter);
+
+/* Decrements the number of attached contexts on an adapter */
+void cxl_adapter_context_put(struct cxl *adapter);
+
+/* If no active contexts then prevents contexts from being attached */
+int cxl_adapter_context_lock(struct cxl *adapter);
+
+/* Unlock the contexts-lock if taken. Warn and force unlock otherwise */
+void cxl_adapter_context_unlock(struct cxl *adapter);
+
 #endif
diff --git a/drivers/misc/cxl/file.c b/drivers/misc/cxl/file.c
index 5fb9894b1..d0b421f49 100644
--- a/drivers/misc/cxl/file.c
+++ b/drivers/misc/cxl/file.c
@@ -205,11 +205,22 @@ static long afu_ioctl_start_work(struct cxl_context *ctx,
 	ctx->pid = get_task_pid(current, PIDTYPE_PID);
 	ctx->glpid = get_task_pid(current->group_leader, PIDTYPE_PID);
 
+	/*
+	 * Increment the mapped context count for adapter. This also checks
+	 * if adapter_context_lock is taken.
+	 */
+	rc = cxl_adapter_context_get(ctx->afu->adapter);
+	if (rc) {
+		afu_release_irqs(ctx, ctx);
+		goto out;
+	}
+
 	trace_cxl_attach(ctx, work.work_element_descriptor, work.num_interrupts, amr);
 
 	if ((rc = cxl_ops->attach_process(ctx, false, work.work_element_descriptor,
 							amr))) {
 		afu_release_irqs(ctx, ctx);
+		cxl_adapter_context_put(ctx->afu->adapter);
 		goto out;
 	}
 
diff --git a/drivers/misc/cxl/guest.c b/drivers/misc/cxl/guest.c
index 9aa58a77a..3e102cd6e 100644
--- a/drivers/misc/cxl/guest.c
+++ b/drivers/misc/cxl/guest.c
@@ -1152,6 +1152,9 @@ struct cxl *cxl_guest_init_adapter(struct device_node *np, struct platform_devic
 	if ((rc = cxl_sysfs_adapter_add(adapter)))
 		goto err_put1;
 
+	/* release the context lock as the adapter is configured */
+	cxl_adapter_context_unlock(adapter);
+
 	return adapter;
 
 err_put1:
diff --git a/drivers/misc/cxl/main.c b/drivers/misc/cxl/main.c
index d9be23b24..62e0dfb5f 100644
--- a/drivers/misc/cxl/main.c
+++ b/drivers/misc/cxl/main.c
@@ -243,8 +243,10 @@ struct cxl *cxl_alloc_adapter(void)
 	if (dev_set_name(&adapter->dev, "card%i", adapter->adapter_num))
 		goto err2;
 
-	return adapter;
+	/* start with context lock taken */
+	atomic_set(&adapter->contexts_num, -1);
 
+	return adapter;
 err2:
 	cxl_remove_adapter_nr(adapter);
 err1:
@@ -286,6 +288,44 @@ int cxl_afu_select_best_mode(struct cxl_afu *afu)
 	return 0;
 }
 
+int cxl_adapter_context_get(struct cxl *adapter)
+{
+	int rc;
+
+	rc = atomic_inc_unless_negative(&adapter->contexts_num);
+	return rc >= 0 ? 0 : -EBUSY;
+}
+
+void cxl_adapter_context_put(struct cxl *adapter)
+{
+	atomic_dec_if_positive(&adapter->contexts_num);
+}
+
+int cxl_adapter_context_lock(struct cxl *adapter)
+{
+	int rc;
+	/* no active contexts -> contexts_num == 0 */
+	rc = atomic_cmpxchg(&adapter->contexts_num, 0, -1);
+	return rc ? -EBUSY : 0;
+}
+
+void cxl_adapter_context_unlock(struct cxl *adapter)
+{
+	int val = atomic_cmpxchg(&adapter->contexts_num, -1, 0);
+
+	/*
+	 * contexts lock taken -> contexts_num == -1
+	 * If not true then show a warning and force reset the lock.
+	 * This will happen when context_unlock was requested without
+	 * doing a context_lock.
+	 */
+	if (val != -1) {
+		atomic_set(&adapter->contexts_num, 0);
+		WARN(1, "Adapter context unlocked with %d active contexts",
+		     val);
+	}
+}
+
 static int __init init_cxl(void)
 {
 	int rc = 0;
diff --git a/drivers/misc/cxl/pci.c b/drivers/misc/cxl/pci.c
index 6f0c4ac4b..8ad4e4f6f 100644
--- a/drivers/misc/cxl/pci.c
+++ b/drivers/misc/cxl/pci.c
@@ -1484,6 +1484,8 @@ static int cxl_configure_adapter(struct cxl *adapter, struct pci_dev *dev)
 	if ((rc = cxl_native_register_psl_err_irq(adapter)))
 		goto err;
 
+	/* Release the context lock as adapter is configured */
+	cxl_adapter_context_unlock(adapter);
 	return 0;
 
 err:
diff --git a/drivers/misc/cxl/sysfs.c b/drivers/misc/cxl/sysfs.c
index b043c20f1..a8b6d6a63 100644
--- a/drivers/misc/cxl/sysfs.c
+++ b/drivers/misc/cxl/sysfs.c
@@ -75,12 +75,31 @@ static ssize_t reset_adapter_store(struct device *device,
 	int val;
 
 	rc = sscanf(buf, "%i", &val);
-	if ((rc != 1) || (val != 1))
+	if ((rc != 1) || (val != 1 && val != -1))
 		return -EINVAL;
 
-	if ((rc = cxl_ops->adapter_reset(adapter)))
-		return rc;
-	return count;
+	/*
+	 * See if we can lock the context mapping that's only allowed
+	 * when there are no contexts attached to the adapter. Once
+	 * taken this will also prevent any context from getting activated.
+	 */
+	if (val == 1) {
+		rc =  cxl_adapter_context_lock(adapter);
+		if (rc)
+			goto out;
+
+		rc = cxl_ops->adapter_reset(adapter);
+		/* In case reset failed release context lock */
+		if (rc)
+			cxl_adapter_context_unlock(adapter);
+
+	} else if (val == -1) {
+		/* Perform a forced adapter reset */
+		rc = cxl_ops->adapter_reset(adapter);
+	}
+
+out:
+	return rc ? rc : count;
 }
 
 static ssize_t load_image_on_perst_show(struct device *device,
diff --git a/drivers/misc/mei/amthif.c b/drivers/misc/mei/amthif.c
index fd9271bc1..cd01e342b 100644
--- a/drivers/misc/mei/amthif.c
+++ b/drivers/misc/mei/amthif.c
@@ -139,7 +139,7 @@ int mei_amthif_read(struct mei_device *dev, struct file *file,
 			return -ERESTARTSYS;
 
 		if (!mei_cl_is_connected(cl)) {
-			rets = -EBUSY;
+			rets = -ENODEV;
 			goto out;
 		}
 
diff --git a/drivers/misc/mei/bus.c b/drivers/misc/mei/bus.c
index e094df3cf..5b5b2e07e 100644
--- a/drivers/misc/mei/bus.c
+++ b/drivers/misc/mei/bus.c
@@ -142,7 +142,7 @@ ssize_t __mei_cl_recv(struct mei_cl *cl, u8 *buf, size_t length)
 		mutex_lock(&bus->device_lock);
 
 		if (!mei_cl_is_connected(cl)) {
-			rets = -EBUSY;
+			rets = -ENODEV;
 			goto out;
 		}
 	}
diff --git a/drivers/misc/mei/hw-me-regs.h b/drivers/misc/mei/hw-me-regs.h
index 0dcb854b4..7ad15d678 100644
--- a/drivers/misc/mei/hw-me-regs.h
+++ b/drivers/misc/mei/hw-me-regs.h
@@ -125,6 +125,9 @@
 #define MEI_DEV_ID_BXT_M      0x1A9A  /* Broxton M */
 #define MEI_DEV_ID_APL_I      0x5A9A  /* Apollo Lake I */
 
+#define MEI_DEV_ID_KBP        0xA2BA  /* Kaby Point */
+#define MEI_DEV_ID_KBP_2      0xA2BB  /* Kaby Point 2 */
+
 /*
  * MEI HW Section
  */
diff --git a/drivers/misc/mei/main.c b/drivers/misc/mei/main.c
index 52635b063..080208dc5 100644
--- a/drivers/misc/mei/main.c
+++ b/drivers/misc/mei/main.c
@@ -202,7 +202,7 @@ static ssize_t mei_read(struct file *file, char __user *ubuf,
 
 		mutex_lock(&dev->device_lock);
 		if (!mei_cl_is_connected(cl)) {
-			rets = -EBUSY;
+			rets = -ENODEV;
 			goto out;
 		}
 	}
diff --git a/drivers/misc/mei/pci-me.c b/drivers/misc/mei/pci-me.c
index 71cea9b29..5eb9b75ae 100644
--- a/drivers/misc/mei/pci-me.c
+++ b/drivers/misc/mei/pci-me.c
@@ -91,6 +91,9 @@ static const struct pci_device_id mei_me_pci_tbl[] = {
 	{MEI_PCI_DEVICE(MEI_DEV_ID_BXT_M, mei_me_pch8_cfg)},
 	{MEI_PCI_DEVICE(MEI_DEV_ID_APL_I, mei_me_pch8_cfg)},
 
+	{MEI_PCI_DEVICE(MEI_DEV_ID_KBP, mei_me_pch8_cfg)},
+	{MEI_PCI_DEVICE(MEI_DEV_ID_KBP_2, mei_me_pch8_cfg)},
+
 	/* required last entry */
 	{0, }
 };
-- 
cgit v1.2.3-54-g00ecf