[PATCH v5 0/7] ocxl: Implement Power9 as_notify/wait for OpenCAPI

  arch/powerpc/kernel/process.c | 6 +++---
  1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 1237f13fed51..3b00da47699b 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c

@@ -1154,7 +1154,7 @@ static inline void restore_sprs(struct thread_struct *old_thread,
  			mtspr(SPRN_TAR, new_thread->tar);
  	}

-	if (cpu_has_feature(CPU_FTR_ARCH_300) &&
+	if (cpu_has_feature(CPU_FTR_P9_TIDR) &&
  	    old_thread->tidr != new_thread->tidr)
  		mtspr(SPRN_TIDR, new_thread->tidr);
  #endif

@@ -1570,7 +1570,7 @@ void clear_thread_tidr(struct task_struct *t)
  	if (!t->thread.tidr)
  		return;

-	if (!cpu_has_feature(CPU_FTR_ARCH_300)) {
+	if (!cpu_has_feature(CPU_FTR_P9_TIDR)) {
  		WARN_ON_ONCE(1);
  		return;
  	}

@@ -1593,7 +1593,7 @@ int set_thread_tidr(struct task_struct *t)
  {
  	int rc;

-	if (!cpu_has_feature(CPU_FTR_ARCH_300))
+	if (!cpu_has_feature(CPU_FTR_P9_TIDR))
  		return -EINVAL;

  	if (t != current)

  Documentation/accelerators/ocxl.rst | 11 +++++++++++
  1 file changed, 11 insertions(+)

diff --git a/Documentation/accelerators/ocxl.rst b/Documentation/accelerators/ocxl.rst
index ddcc58d01cfb..14cefc020e2d 100644
--- a/Documentation/accelerators/ocxl.rst
+++ b/Documentation/accelerators/ocxl.rst

@@ -157,6 +157,17 @@ OCXL_IOCTL_GET_METADATA:
    Obtains configuration information from the card, such at the size of
    MMIO areas, the AFU version, and the PASID for the current context.

+OCXL_IOCTL_ENABLE_P9_WAIT:
+
+  Allows the AFU to wake a userspace thread executing 'wait'. Returns
+  information to userspace to allow it to configure the AFU. Note that
+  this is only available on POWER9.
+
+OCXL_IOCTL_GET_FEATURES:
+
+  Reports on which CPU features that affect OpenCAPI are usable from
+  userspace.
+

  mmap
  ----

  drivers/misc/ocxl/file.c | 25 +++++++++++++++++++++++++
  include/uapi/misc/ocxl.h |  6 ++++++
  2 files changed, 31 insertions(+)

diff --git a/drivers/misc/ocxl/file.c b/drivers/misc/ocxl/file.c
index eb409a469f21..33ae46ce0a8a 100644
--- a/drivers/misc/ocxl/file.c
+++ b/drivers/misc/ocxl/file.c

@@ -168,12 +168,32 @@ static long afu_ioctl_enable_p9_wait(struct ocxl_context *ctx,
  }
  #endif

+
+static long afu_ioctl_get_features(struct ocxl_context *ctx,
+		struct ocxl_ioctl_features __user *uarg)
+{
+	struct ocxl_ioctl_features arg;
+
+	memset(&arg, 0, sizeof(arg));
+
+#ifdef CONFIG_PPC64
+	if (cpu_has_feature(CPU_FTR_P9_TIDR))
+		arg.flags[0] |= OCXL_IOCTL_FEATURES_FLAGS0_P9_WAIT;
+#endif
+
+	if (copy_to_user(uarg, &arg, sizeof(arg)))
+		return -EFAULT;
+
+	return 0;
+}
+
  #define CMD_STR(x) (x == OCXL_IOCTL_ATTACH ? "ATTACH" :			\
  			x == OCXL_IOCTL_IRQ_ALLOC ? "IRQ_ALLOC" :	\
  			x == OCXL_IOCTL_IRQ_FREE ? "IRQ_FREE" :		\
  			x == OCXL_IOCTL_IRQ_SET_FD ? "IRQ_SET_FD" :	\
  			x == OCXL_IOCTL_GET_METADATA ? "GET_METADATA" :	\
  			x == OCXL_IOCTL_ENABLE_P9_WAIT ? "ENABLE_P9_WAIT" :	\
+			x == OCXL_IOCTL_GET_FEATURES ? "GET_FEATURES" :	\
  			"UNKNOWN")

  static long afu_ioctl(struct file *file, unsigned int cmd,

@@ -239,6 +259,11 @@ static long afu_ioctl(struct file *file, unsigned int cmd,
  		break;
  #endif

+	case OCXL_IOCTL_GET_FEATURES:
+		rc = afu_ioctl_get_features(ctx,
+				(struct ocxl_ioctl_features __user *) args);
+		break;
+
  	default:
  		rc = -EINVAL;
  	}

diff --git a/include/uapi/misc/ocxl.h b/include/uapi/misc/ocxl.h
index 561e6f0dfcb7..97937cfa3baa 100644
--- a/include/uapi/misc/ocxl.h
+++ b/include/uapi/misc/ocxl.h

@@ -55,6 +55,11 @@ struct ocxl_ioctl_p9_wait {
  	__u64 reserved3[3];
  };

+#define OCXL_IOCTL_FEATURES_FLAGS0_P9_WAIT	0x01
+struct ocxl_ioctl_features {
+	__u64 flags[4];
+};
+
  struct ocxl_ioctl_irq_fd {
  	__u64 irq_offset;
  	__s32 eventfd;

@@ -70,5 +75,6 @@ struct ocxl_ioctl_irq_fd {
  #define OCXL_IOCTL_IRQ_SET_FD	_IOW(OCXL_MAGIC, 0x13, struct ocxl_ioctl_irq_fd)
  #define OCXL_IOCTL_GET_METADATA _IOR(OCXL_MAGIC, 0x14, struct ocxl_ioctl_metadata)
  #define OCXL_IOCTL_ENABLE_P9_WAIT	_IOR(OCXL_MAGIC, 0x15, struct ocxl_ioctl_p9_wait)
+#define OCXL_IOCTL_GET_FEATURES _IOR(OCXL_MAGIC, 0x16, struct ocxl_ioctl_features)

  #endif /* _UAPI_MISC_OCXL_H */

  arch/powerpc/include/asm/switch_to.h |   1 -
  arch/powerpc/kernel/process.c        | 122 ++++++---------------------
  2 files changed, 28 insertions(+), 95 deletions(-)

diff --git a/arch/powerpc/include/asm/switch_to.h b/arch/powerpc/include/asm/switch_to.h
index be8c9fa23983..5b03d8a82409 100644
--- a/arch/powerpc/include/asm/switch_to.h
+++ b/arch/powerpc/include/asm/switch_to.h

@@ -94,6 +94,5 @@ static inline void clear_task_ebb(struct task_struct *t)
  extern int set_thread_uses_vas(void);

  extern int set_thread_tidr(struct task_struct *t);
-extern void clear_thread_tidr(struct task_struct *t);

  #endif /* _ASM_POWERPC_SWITCH_TO_H */

diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 3b00da47699b..c5b8e53acbae 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c

@@ -1496,103 +1496,41 @@ int set_thread_uses_vas(void)
  }

  #ifdef CONFIG_PPC64
-static DEFINE_SPINLOCK(vas_thread_id_lock);
-static DEFINE_IDA(vas_thread_ida);
-
-/*
- * We need to assign a unique thread id to each thread in a process.
+/**
+ * Assign a TIDR (thread ID) for task @t and set it in the thread
+ * structure. For now, we only support setting TIDR for 'current' task.
   *
- * This thread id, referred to as TIDR, and separate from the Linux's tgid,
- * is intended to be used to direct an ASB_Notify from the hardware to the
- * thread, when a suitable event occurs in the system.
+ * Since the TID value is a truncated form of it PID, it is possible
+ * (but unlikely) for 2 threads to have the same TID. In the unlikely event
+ * that 2 threads share the same TID and are waiting, one of the following
+ * cases will happen:
   *
- * One such event is a "paste" instruction in the context of Fast Thread
- * Wakeup (aka Core-to-core wake up in the Virtual Accelerator Switchboard
- * (VAS) in POWER9.
+ * 1. The correct thread is running, the wrong thread is not
+ * In this situation, the correct thread is woken and proceeds to pass it's
+ * condition check.
   *
- * To get a unique TIDR per process we could simply reuse task_pid_nr() but
- * the problem is that task_pid_nr() is not yet available copy_thread() is
- * called. Fixing that would require changing more intrusive arch-neutral
- * code in code path in copy_process()?.
+ * 2. Neither threads are running
+ * In this situation, neither thread will be woken. When scheduled, the waiting
+ * threads will execute either a wait, which will return immediately, followed
+ * by a condition check, which will pass for the correct thread and fail
+ * for the wrong thread, or they will execute the condition check immediately.
   *
- * Further, to assign unique TIDRs within each process, we need an atomic
- * field (or an IDR) in task_struct, which again intrudes into the arch-
- * neutral code. So try to assign globally unique TIDRs for now.
+ * 3. The wrong thread is running, the correct thread is not
+ * The wrong thread will be woken, but will fail it's condition check and
+ * re-execute wait. The correct thread, when scheduled, will execute either
+ * it's condition check (which will pass), or wait, which returns immediately
+ * when called the first time after the thread is scheduled, followed by it's
+ * condition check (which will pass).
   *
- * NOTE: TIDR 0 indicates that the thread does not need a TIDR value.
- *	 For now, only threads that expect to be notified by the VAS
- *	 hardware need a TIDR value and we assign values > 0 for those.
- */
-#define MAX_THREAD_CONTEXT	((1 << 16) - 1)
-static int assign_thread_tidr(void)
-{
-	int index;
-	int err;
-	unsigned long flags;
-
-again:
-	if (!ida_pre_get(&vas_thread_ida, GFP_KERNEL))
-		return -ENOMEM;
-
-	spin_lock_irqsave(&vas_thread_id_lock, flags);
-	err = ida_get_new_above(&vas_thread_ida, 1, &index);
-	spin_unlock_irqrestore(&vas_thread_id_lock, flags);
-
-	if (err == -EAGAIN)
-		goto again;
-	else if (err)
-		return err;
-
-	if (index > MAX_THREAD_CONTEXT) {
-		spin_lock_irqsave(&vas_thread_id_lock, flags);
-		ida_remove(&vas_thread_ida, index);
-		spin_unlock_irqrestore(&vas_thread_id_lock, flags);
-		return -ENOMEM;
-	}
-
-	return index;
-}
-
-static void free_thread_tidr(int id)
-{
-	unsigned long flags;
-
-	spin_lock_irqsave(&vas_thread_id_lock, flags);
-	ida_remove(&vas_thread_ida, id);
-	spin_unlock_irqrestore(&vas_thread_id_lock, flags);
-}
-
-/*
- * Clear any TIDR value assigned to this thread.
- */
-void clear_thread_tidr(struct task_struct *t)
-{
-	if (!t->thread.tidr)
-		return;
-
-	if (!cpu_has_feature(CPU_FTR_P9_TIDR)) {
-		WARN_ON_ONCE(1);
-		return;
-	}
-
-	mtspr(SPRN_TIDR, 0);
-	free_thread_tidr(t->thread.tidr);
-	t->thread.tidr = 0;
-}
-
-void arch_release_task_struct(struct task_struct *t)
-{
-	clear_thread_tidr(t);
-}
-
-/*
- * Assign a unique TIDR (thread id) for task @t and set it in the thread
- * structure. For now, we only support setting TIDR for 'current' task.
+ * 4. Both threads are running
+ * Both threads will be woken. The wrong thread will fail it's condition check
+ * and execute another wait, while the correct thread will pass it's condition
+ * check.
+ *
+ * @t: the task to set the thread ID for
   */
  int set_thread_tidr(struct task_struct *t)
  {
-	int rc;
-
  	if (!cpu_has_feature(CPU_FTR_P9_TIDR))
  		return -EINVAL;

@@ -1602,11 +1540,7 @@ int set_thread_tidr(struct task_struct *t)
  	if (t->thread.tidr)
  		return 0;

-	rc = assign_thread_tidr();
-	if (rc < 0)
-		return rc;
-
-	t->thread.tidr = rc;
+	t->thread.tidr = (u16)task_pid_nr(t);
  	mtspr(SPRN_TIDR, t->thread.tidr);

  	return 0;

  arch/powerpc/include/asm/pnv-ocxl.h   | 2 +-
  arch/powerpc/platforms/powernv/ocxl.c | 4 ++--
  drivers/misc/ocxl/link.c              | 2 +-
  3 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/include/asm/pnv-ocxl.h b/arch/powerpc/include/asm/pnv-ocxl.h
index f6945d3bc971..208b5503f4ed 100644
--- a/arch/powerpc/include/asm/pnv-ocxl.h
+++ b/arch/powerpc/include/asm/pnv-ocxl.h

@@ -28,7 +28,7 @@ extern int pnv_ocxl_map_xsl_regs(struct pci_dev *dev, void __iomem **dsisr,
  extern int pnv_ocxl_spa_setup(struct pci_dev *dev, void *spa_mem, int PE_mask,
  			void **platform_data);
  extern void pnv_ocxl_spa_release(void *platform_data);
-extern int pnv_ocxl_spa_remove_pe(void *platform_data, int pe_handle);
+extern int pnv_ocxl_spa_remove_pe_from_cache(void *platform_data, int pe_handle);

  extern int pnv_ocxl_alloc_xive_irq(u32 *irq, u64 *trigger_addr);
  extern void pnv_ocxl_free_xive_irq(u32 irq);

diff --git a/arch/powerpc/platforms/powernv/ocxl.c b/arch/powerpc/platforms/powernv/ocxl.c
index fa9b53af3c7b..8c65aacda9c8 100644
--- a/arch/powerpc/platforms/powernv/ocxl.c
+++ b/arch/powerpc/platforms/powernv/ocxl.c

@@ -475,7 +475,7 @@ void pnv_ocxl_spa_release(void *platform_data)
  }
  EXPORT_SYMBOL_GPL(pnv_ocxl_spa_release);

-int pnv_ocxl_spa_remove_pe(void *platform_data, int pe_handle)
+int pnv_ocxl_spa_remove_pe_from_cache(void *platform_data, int pe_handle)
  {
  	struct spa_data *data = (struct spa_data *) platform_data;
  	int rc;

@@ -483,7 +483,7 @@ int pnv_ocxl_spa_remove_pe(void *platform_data, int pe_handle)
  	rc = opal_npu_spa_clear_cache(data->phb_opal_id, data->bdfn, pe_handle);
  	return rc;
  }
-EXPORT_SYMBOL_GPL(pnv_ocxl_spa_remove_pe);
+EXPORT_SYMBOL_GPL(pnv_ocxl_spa_remove_pe_from_cache);

  int pnv_ocxl_alloc_xive_irq(u32 *irq, u64 *trigger_addr)
  {

diff --git a/drivers/misc/ocxl/link.c b/drivers/misc/ocxl/link.c
index f30790582dc0..656e8610eec2 100644
--- a/drivers/misc/ocxl/link.c
+++ b/drivers/misc/ocxl/link.c

@@ -599,7 +599,7 @@ int ocxl_link_remove_pe(void *link_handle, int pasid)
  	 * On powerpc, the entry needs to be cleared from the context
  	 * cache of the NPU.
  	 */
-	rc = pnv_ocxl_spa_remove_pe(link->platform_data, pe_handle);
+	rc = pnv_ocxl_spa_remove_pe_from_cache(link->platform_data, pe_handle);
  	WARN_ON(rc);

  	pe_data = radix_tree_delete(&spa->pe_tree, pe_handle);

  drivers/misc/ocxl/context.c       |  5 ++-
  drivers/misc/ocxl/file.c          | 53 +++++++++++++++++++++++++++++++
  drivers/misc/ocxl/link.c          | 36 +++++++++++++++++++++
  drivers/misc/ocxl/ocxl_internal.h |  1 +
  include/misc/ocxl.h               |  9 ++++++
  include/uapi/misc/ocxl.h          |  8 +++++
  6 files changed, 111 insertions(+), 1 deletion(-)

diff --git a/drivers/misc/ocxl/context.c b/drivers/misc/ocxl/context.c
index 909e8807824a..95f74623113e 100644
--- a/drivers/misc/ocxl/context.c
+++ b/drivers/misc/ocxl/context.c

@@ -34,6 +34,8 @@ int ocxl_context_init(struct ocxl_context *ctx, struct ocxl_afu *afu,
  	mutex_init(&ctx->xsl_error_lock);
  	mutex_init(&ctx->irq_lock);
  	idr_init(&ctx->irq_idr);
+	ctx->tidr = 0;
+
  	/*
  	 * Keep a reference on the AFU to make sure it's valid for the
  	 * duration of the life of the context

@@ -65,6 +67,7 @@ int ocxl_context_attach(struct ocxl_context *ctx, u64 amr)
  {
  	int rc;

+	// Locks both status & tidr
  	mutex_lock(&ctx->status_mutex);
  	if (ctx->status != OPENED) {
  		rc = -EIO;

@@ -72,7 +75,7 @@ int ocxl_context_attach(struct ocxl_context *ctx, u64 amr)
  	}

  	rc = ocxl_link_add_pe(ctx->afu->fn->link, ctx->pasid,
-			current->mm->context.id, 0, amr, current->mm,
+			current->mm->context.id, ctx->tidr, amr, current->mm,
  			xsl_fault_error, ctx);
  	if (rc)
  		goto out;

diff --git a/drivers/misc/ocxl/file.c b/drivers/misc/ocxl/file.c
index 038509e5d031..eb409a469f21 100644
--- a/drivers/misc/ocxl/file.c
+++ b/drivers/misc/ocxl/file.c

@@ -5,6 +5,8 @@
  #include <linux/sched/signal.h>
  #include <linux/uaccess.h>
  #include <uapi/misc/ocxl.h>
+#include <asm/reg.h>
+#include <asm/switch_to.h>
  #include "ocxl_internal.h"

@@ -123,11 +125,55 @@ static long afu_ioctl_get_metadata(struct ocxl_context *ctx,
  	return 0;
  }

+#ifdef CONFIG_PPC64
+static long afu_ioctl_enable_p9_wait(struct ocxl_context *ctx,
+		struct ocxl_ioctl_p9_wait __user *uarg)
+{
+	struct ocxl_ioctl_p9_wait arg;
+
+	memset(&arg, 0, sizeof(arg));
+
+	if (cpu_has_feature(CPU_FTR_P9_TIDR)) {
+		enum ocxl_context_status status;
+
+		// Locks both status & tidr
+		mutex_lock(&ctx->status_mutex);
+		if (!ctx->tidr) {
+			if (set_thread_tidr(current))
+				return -ENOENT;
+
+			ctx->tidr = current->thread.tidr;
+		}
+
+		status = ctx->status;
+		mutex_unlock(&ctx->status_mutex);
+
+		if (status == ATTACHED) {
+			int rc;
+			struct link *link = ctx->afu->fn->link;
+
+			rc = ocxl_link_update_pe(link, ctx->pasid, ctx->tidr);
+			if (rc)
+				return rc;
+		}
+
+		arg.thread_id = ctx->tidr;
+	} else
+		return -ENOENT;
+
+	if (copy_to_user(uarg, &arg, sizeof(arg)))
+		return -EFAULT;
+
+	return 0;
+}
+#endif
+
  #define CMD_STR(x) (x == OCXL_IOCTL_ATTACH ? "ATTACH" :			\
  			x == OCXL_IOCTL_IRQ_ALLOC ? "IRQ_ALLOC" :	\
  			x == OCXL_IOCTL_IRQ_FREE ? "IRQ_FREE" :		\
  			x == OCXL_IOCTL_IRQ_SET_FD ? "IRQ_SET_FD" :	\
  			x == OCXL_IOCTL_GET_METADATA ? "GET_METADATA" :	\
+			x == OCXL_IOCTL_ENABLE_P9_WAIT ? "ENABLE_P9_WAIT" :	\
  			"UNKNOWN")

  static long afu_ioctl(struct file *file, unsigned int cmd,

@@ -186,6 +232,13 @@ static long afu_ioctl(struct file *file, unsigned int cmd,
  				(struct ocxl_ioctl_metadata __user *) args);
  		break;

+#ifdef CONFIG_PPC64
+	case OCXL_IOCTL_ENABLE_P9_WAIT:
+		rc = afu_ioctl_enable_p9_wait(ctx,
+				(struct ocxl_ioctl_p9_wait __user *) args);
+		break;
+#endif
+
  	default:
  		rc = -EINVAL;
  	}

diff --git a/drivers/misc/ocxl/link.c b/drivers/misc/ocxl/link.c
index 656e8610eec2..88876ae8f330 100644
--- a/drivers/misc/ocxl/link.c
+++ b/drivers/misc/ocxl/link.c

@@ -544,6 +544,42 @@ int ocxl_link_add_pe(void *link_handle, int pasid, u32 pidr, u32 tidr,
  }
  EXPORT_SYMBOL_GPL(ocxl_link_add_pe);

+int ocxl_link_update_pe(void *link_handle, int pasid, __u16 tid)
+{
+	struct link *link = (struct link *) link_handle;
+	struct spa *spa = link->spa;
+	struct ocxl_process_element *pe;
+	int pe_handle, rc;
+
+	if (pasid > SPA_PASID_MAX)
+		return -EINVAL;
+
+	pe_handle = pasid & SPA_PE_MASK;
+	pe = spa->spa_mem + pe_handle;
+
+	mutex_lock(&spa->spa_lock);
+
+	pe->tid = tid;
+
+	/*
+	 * The barrier makes sure the PE is updated
+	 * before we clear the NPU context cache below, so that the
+	 * old PE cannot be reloaded erroneously.
+	 */
+	mb();
+
+	/*
+	 * hook to platform code
+	 * On powerpc, the entry needs to be cleared from the context
+	 * cache of the NPU.
+	 */
+	rc = pnv_ocxl_spa_remove_pe_from_cache(link->platform_data, pe_handle);
+	WARN_ON(rc);
+
+	mutex_unlock(&spa->spa_lock);
+	return rc;
+}
+
  int ocxl_link_remove_pe(void *link_handle, int pasid)
  {
  	struct link *link = (struct link *) link_handle;

diff --git a/drivers/misc/ocxl/ocxl_internal.h b/drivers/misc/ocxl/ocxl_internal.h
index 5d421824afd9..a32f2151029f 100644
--- a/drivers/misc/ocxl/ocxl_internal.h
+++ b/drivers/misc/ocxl/ocxl_internal.h

@@ -77,6 +77,7 @@ struct ocxl_context {
  	struct ocxl_xsl_error xsl_error;
  	struct mutex irq_lock;
  	struct idr irq_idr;
+	u16 tidr; // Thread ID used for P9 wait implementation
  };

  struct ocxl_process_element {

diff --git a/include/misc/ocxl.h b/include/misc/ocxl.h
index 51ccf76db293..9ff6ddc28e22 100644
--- a/include/misc/ocxl.h
+++ b/include/misc/ocxl.h

@@ -188,6 +188,15 @@ extern int ocxl_link_add_pe(void *link_handle, int pasid, u32 pidr, u32 tidr,
  		void (*xsl_err_cb)(void *data, u64 addr, u64 dsisr),
  		void *xsl_err_data);

+/**
+ * Update values within a Process Element
+ *
+ * link_handle: the link handle associated with the process element
+ * pasid: the PASID for the AFU context
+ * tid: the new thread id for the process element
+ */
+extern int ocxl_link_update_pe(void *link_handle, int pasid, __u16 tid);
+
  /*
   * Remove a Process Element from the Shared Process Area for a link
   */

diff --git a/include/uapi/misc/ocxl.h b/include/uapi/misc/ocxl.h
index 0af83d80fb3e..561e6f0dfcb7 100644
--- a/include/uapi/misc/ocxl.h
+++ b/include/uapi/misc/ocxl.h

@@ -48,6 +48,13 @@ struct ocxl_ioctl_metadata {
  	__u64 reserved[13]; // Total of 16*u64
  };

+struct ocxl_ioctl_p9_wait {
+	__u16 thread_id; // The thread ID required to wake this thread
+	__u16 reserved1;
+	__u32 reserved2;
+	__u64 reserved3[3];
+};
+
  struct ocxl_ioctl_irq_fd {
  	__u64 irq_offset;
  	__s32 eventfd;

@@ -62,5 +69,6 @@ struct ocxl_ioctl_irq_fd {
  #define OCXL_IOCTL_IRQ_FREE	_IOW(OCXL_MAGIC, 0x12, __u64)
  #define OCXL_IOCTL_IRQ_SET_FD	_IOW(OCXL_MAGIC, 0x13, struct ocxl_ioctl_irq_fd)
  #define OCXL_IOCTL_GET_METADATA _IOR(OCXL_MAGIC, 0x14, struct ocxl_ioctl_metadata)
+#define OCXL_IOCTL_ENABLE_P9_WAIT	_IOR(OCXL_MAGIC, 0x15, struct ocxl_ioctl_p9_wait)

  #endif /* _UAPI_MISC_OCXL_H */