cxl: Driver code for powernv PCIe based cards for userspace access

This is the core of the cxl driver.

It adds support for using cxl cards in the powernv environment only (ie POWER8
bare metal). It allows access to cxl accelerators by userspace using the
/dev/cxl/afuM.N char devices.

The kernel driver has no knowledge of the function implemented by the
accelerator. It provides services to userspace via the /dev/cxl/afuM.N
devices. When a program opens this device and runs the start work IOCTL, the
accelerator will have coherent access to that processes memory using the same
virtual addresses. That process may mmap the device to access any MMIO space
the accelerator provides.  Also, reads on the device will allow interrupts to
be received. These services are further documented in a later patch in
Documentation/powerpc/cxl.txt.

Documentation of the cxl hardware architecture and userspace API is provided in
subsequent patches.

Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

10 files changed, 4453 insertions, 0 deletions

diff --git a/drivers/misc/cxl/context.c b/drivers/misc/cxl/context.c
new file mode 100644
index 000000000000..cca472109135
--- /dev/null
+++ b/drivers/misc/cxl/context.c
@@ -0,0 +1,193 @@
+/*
+ * Copyright 2014 IBM Corp.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/bitmap.h>
+#include <linux/sched.h>
+#include <linux/pid.h>
+#include <linux/fs.h>
+#include <linux/mm.h>
+#include <linux/debugfs.h>
+#include <linux/slab.h>
+#include <linux/idr.h>
+#include <asm/cputable.h>
+#include <asm/current.h>
+#include <asm/copro.h>
+
+#include "cxl.h"
+
+/*
+ * Allocates space for a CXL context.
+ */
+struct cxl_context *cxl_context_alloc(void)
+{
+	return kzalloc(sizeof(struct cxl_context), GFP_KERNEL);
+}
+
+/*
+ * Initialises a CXL context.
+ */
+int cxl_context_init(struct cxl_context *ctx, struct cxl_afu *afu, bool master)
+{
+	int i;
+
+	spin_lock_init(&ctx->sste_lock);
+	ctx->afu = afu;
+	ctx->master = master;
+	ctx->pid = NULL; /* Set in start work ioctl */
+
+	/*
+	 * Allocate the segment table before we put it in the IDR so that we
+	 * can always access it when dereferenced from IDR. For the same
+	 * reason, the segment table is only destroyed after the context is
+	 * removed from the IDR.  Access to this in the IOCTL is protected by
+	 * Linux filesytem symantics (can't IOCTL until open is complete).
+	 */
+	i = cxl_alloc_sst(ctx);
+	if (i)
+		return i;
+
+	INIT_WORK(&ctx->fault_work, cxl_handle_fault);
+
+	init_waitqueue_head(&ctx->wq);
+	spin_lock_init(&ctx->lock);
+
+	ctx->irq_bitmap = NULL;
+	ctx->pending_irq = false;
+	ctx->pending_fault = false;
+	ctx->pending_afu_err = false;
+
+	/*
+	 * When we have to destroy all contexts in cxl_context_detach_all() we
+	 * end up with afu_release_irqs() called from inside a
+	 * idr_for_each_entry(). Hence we need to make sure that anything
+	 * dereferenced from this IDR is ok before we allocate the IDR here.
+	 * This clears out the IRQ ranges to ensure this.
+	 */
+	for (i = 0; i < CXL_IRQ_RANGES; i++)
+		ctx->irqs.range[i] = 0;
+
+	mutex_init(&ctx->status_mutex);
+
+	ctx->status = OPENED;
+
+	/*
+	 * Allocating IDR! We better make sure everything's setup that
+	 * dereferences from it.
+	 */
+	idr_preload(GFP_KERNEL);
+	spin_lock(&afu->contexts_lock);
+	i = idr_alloc(&ctx->afu->contexts_idr, ctx, 0,
+		      ctx->afu->num_procs, GFP_NOWAIT);
+	spin_unlock(&afu->contexts_lock);
+	idr_preload_end();
+	if (i < 0)
+		return i;
+
+	ctx->pe = i;
+	ctx->elem = &ctx->afu->spa[i];
+	ctx->pe_inserted = false;
+	return 0;
+}
+
+/*
+ * Map a per-context mmio space into the given vma.
+ */
+int cxl_context_iomap(struct cxl_context *ctx, struct vm_area_struct *vma)
+{
+	u64 len = vma->vm_end - vma->vm_start;
+	len = min(len, ctx->psn_size);
+
+	if (ctx->afu->current_mode == CXL_MODE_DEDICATED) {
+		vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
+		return vm_iomap_memory(vma, ctx->afu->psn_phys, ctx->afu->adapter->ps_size);
+	}
+
+	/* make sure there is a valid per process space for this AFU */
+	if ((ctx->master && !ctx->afu->psa) || (!ctx->afu->pp_psa)) {
+		pr_devel("AFU doesn't support mmio space\n");
+		return -EINVAL;
+	}
+
+	/* Can't mmap until the AFU is enabled */
+	if (!ctx->afu->enabled)
+		return -EBUSY;
+
+	pr_devel("%s: mmio physical: %llx pe: %i master:%i\n", __func__,
+		 ctx->psn_phys, ctx->pe , ctx->master);
+
+	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
+	return vm_iomap_memory(vma, ctx->psn_phys, len);
+}
+
+/*
+ * Detach a context from the hardware. This disables interrupts and doesn't
+ * return until all outstanding interrupts for this context have completed. The
+ * hardware should no longer access *ctx after this has returned.
+ */
+static void __detach_context(struct cxl_context *ctx)
+{
+	enum cxl_context_status status;
+
+	mutex_lock(&ctx->status_mutex);
+	status = ctx->status;
+	ctx->status = CLOSED;
+	mutex_unlock(&ctx->status_mutex);
+	if (status != STARTED)
+		return;
+
+	WARN_ON(cxl_detach_process(ctx));
+	afu_release_irqs(ctx);
+	flush_work(&ctx->fault_work); /* Only needed for dedicated process */
+	wake_up_all(&ctx->wq);
+}
+
+/*
+ * Detach the given context from the AFU. This doesn't actually
+ * free the context but it should stop the context running in hardware
+ * (ie. prevent this context from generating any further interrupts
+ * so that it can be freed).
+ */
+void cxl_context_detach(struct cxl_context *ctx)
+{
+	__detach_context(ctx);
+}
+
+/*
+ * Detach all contexts on the given AFU.
+ */
+void cxl_context_detach_all(struct cxl_afu *afu)
+{
+	struct cxl_context *ctx;
+	int tmp;
+
+	rcu_read_lock();
+	idr_for_each_entry(&afu->contexts_idr, ctx, tmp)
+		/*
+		 * Anything done in here needs to be setup before the IDR is
+		 * created and torn down after the IDR removed
+		 */
+		__detach_context(ctx);
+	rcu_read_unlock();
+}
+
+void cxl_context_free(struct cxl_context *ctx)
+{
+	spin_lock(&ctx->afu->contexts_lock);
+	idr_remove(&ctx->afu->contexts_idr, ctx->pe);
+	spin_unlock(&ctx->afu->contexts_lock);
+	synchronize_rcu();
+
+	free_page((u64)ctx->sstp);
+	ctx->sstp = NULL;
+
+	put_pid(ctx->pid);
+	kfree(ctx);
+}
diff --git a/drivers/misc/cxl/cxl.h b/drivers/misc/cxl/cxl.h
new file mode 100644
index 000000000000..3d2b8677ec8a
--- /dev/null
+++ b/drivers/misc/cxl/cxl.h
@@ -0,0 +1,629 @@
+/*
+ * Copyright 2014 IBM Corp.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#ifndef _CXL_H_
+#define _CXL_H_
+
+#include <linux/interrupt.h>
+#include <linux/semaphore.h>
+#include <linux/device.h>
+#include <linux/types.h>
+#include <linux/cdev.h>
+#include <linux/pid.h>
+#include <linux/io.h>
+#include <linux/pci.h>
+#include <asm/cputable.h>
+#include <asm/mmu.h>
+#include <asm/reg.h>
+#include <misc/cxl.h>
+
+#include <uapi/misc/cxl.h>
+
+extern uint cxl_verbose;
+
+#define CXL_TIMEOUT 5
+
+/*
+ * Bump version each time a user API change is made, whether it is
+ * backwards compatible ot not.
+ */
+#define CXL_API_VERSION 1
+#define CXL_API_VERSION_COMPATIBLE 1
+
+/*
+ * Opaque types to avoid accidentally passing registers for the wrong MMIO
+ *
+ * At the end of the day, I'm not married to using typedef here, but it might
+ * (and has!) help avoid bugs like mixing up CXL_PSL_CtxTime and
+ * CXL_PSL_CtxTime_An, or calling cxl_p1n_write instead of cxl_p1_write.
+ *
+ * I'm quite happy if these are changed back to #defines before upstreaming, it
+ * should be little more than a regexp search+replace operation in this file.
+ */
+typedef struct {
+	const int x;
+} cxl_p1_reg_t;
+typedef struct {
+	const int x;
+} cxl_p1n_reg_t;
+typedef struct {
+	const int x;
+} cxl_p2n_reg_t;
+#define cxl_reg_off(reg) \
+	(reg.x)
+
+/* Memory maps. Ref CXL Appendix A */
+
+/* PSL Privilege 1 Memory Map */
+/* Configuration and Control area */
+static const cxl_p1_reg_t CXL_PSL_CtxTime = {0x0000};
+static const cxl_p1_reg_t CXL_PSL_ErrIVTE = {0x0008};
+static const cxl_p1_reg_t CXL_PSL_KEY1    = {0x0010};
+static const cxl_p1_reg_t CXL_PSL_KEY2    = {0x0018};
+static const cxl_p1_reg_t CXL_PSL_Control = {0x0020};
+/* Downloading */
+static const cxl_p1_reg_t CXL_PSL_DLCNTL  = {0x0060};
+static const cxl_p1_reg_t CXL_PSL_DLADDR  = {0x0068};
+
+/* PSL Lookaside Buffer Management Area */
+static const cxl_p1_reg_t CXL_PSL_LBISEL  = {0x0080};
+static const cxl_p1_reg_t CXL_PSL_SLBIE   = {0x0088};
+static const cxl_p1_reg_t CXL_PSL_SLBIA   = {0x0090};
+static const cxl_p1_reg_t CXL_PSL_TLBIE   = {0x00A0};
+static const cxl_p1_reg_t CXL_PSL_TLBIA   = {0x00A8};
+static const cxl_p1_reg_t CXL_PSL_AFUSEL  = {0x00B0};
+
+/* 0x00C0:7EFF Implementation dependent area */
+static const cxl_p1_reg_t CXL_PSL_FIR1      = {0x0100};
+static const cxl_p1_reg_t CXL_PSL_FIR2      = {0x0108};
+static const cxl_p1_reg_t CXL_PSL_VERSION   = {0x0118};
+static const cxl_p1_reg_t CXL_PSL_RESLCKTO  = {0x0128};
+static const cxl_p1_reg_t CXL_PSL_FIR_CNTL  = {0x0148};
+static const cxl_p1_reg_t CXL_PSL_DSNDCTL   = {0x0150};
+static const cxl_p1_reg_t CXL_PSL_SNWRALLOC = {0x0158};
+static const cxl_p1_reg_t CXL_PSL_TRACE     = {0x0170};
+/* 0x7F00:7FFF Reserved PCIe MSI-X Pending Bit Array area */
+/* 0x8000:FFFF Reserved PCIe MSI-X Table Area */
+
+/* PSL Slice Privilege 1 Memory Map */
+/* Configuration Area */
+static const cxl_p1n_reg_t CXL_PSL_SR_An          = {0x00};
+static const cxl_p1n_reg_t CXL_PSL_LPID_An        = {0x08};
+static const cxl_p1n_reg_t CXL_PSL_AMBAR_An       = {0x10};
+static const cxl_p1n_reg_t CXL_PSL_SPOffset_An    = {0x18};
+static const cxl_p1n_reg_t CXL_PSL_ID_An          = {0x20};
+static const cxl_p1n_reg_t CXL_PSL_SERR_An        = {0x28};
+/* Memory Management and Lookaside Buffer Management */
+static const cxl_p1n_reg_t CXL_PSL_SDR_An         = {0x30};
+static const cxl_p1n_reg_t CXL_PSL_AMOR_An        = {0x38};
+/* Pointer Area */
+static const cxl_p1n_reg_t CXL_HAURP_An           = {0x80};
+static const cxl_p1n_reg_t CXL_PSL_SPAP_An        = {0x88};
+static const cxl_p1n_reg_t CXL_PSL_LLCMD_An       = {0x90};
+/* Control Area */
+static const cxl_p1n_reg_t CXL_PSL_SCNTL_An       = {0xA0};
+static const cxl_p1n_reg_t CXL_PSL_CtxTime_An     = {0xA8};
+static const cxl_p1n_reg_t CXL_PSL_IVTE_Offset_An = {0xB0};
+static const cxl_p1n_reg_t CXL_PSL_IVTE_Limit_An  = {0xB8};
+/* 0xC0:FF Implementation Dependent Area */
+static const cxl_p1n_reg_t CXL_PSL_FIR_SLICE_An   = {0xC0};
+static const cxl_p1n_reg_t CXL_AFU_DEBUG_An       = {0xC8};
+static const cxl_p1n_reg_t CXL_PSL_APCALLOC_A     = {0xD0};
+static const cxl_p1n_reg_t CXL_PSL_COALLOC_A      = {0xD8};
+static const cxl_p1n_reg_t CXL_PSL_RXCTL_A        = {0xE0};
+static const cxl_p1n_reg_t CXL_PSL_SLICE_TRACE    = {0xE8};
+
+/* PSL Slice Privilege 2 Memory Map */
+/* Configuration and Control Area */
+static const cxl_p2n_reg_t CXL_PSL_PID_TID_An = {0x000};
+static const cxl_p2n_reg_t CXL_CSRP_An        = {0x008};
+static const cxl_p2n_reg_t CXL_AURP0_An       = {0x010};
+static const cxl_p2n_reg_t CXL_AURP1_An       = {0x018};
+static const cxl_p2n_reg_t CXL_SSTP0_An       = {0x020};
+static const cxl_p2n_reg_t CXL_SSTP1_An       = {0x028};
+static const cxl_p2n_reg_t CXL_PSL_AMR_An     = {0x030};
+/* Segment Lookaside Buffer Management */
+static const cxl_p2n_reg_t CXL_SLBIE_An       = {0x040};
+static const cxl_p2n_reg_t CXL_SLBIA_An       = {0x048};
+static const cxl_p2n_reg_t CXL_SLBI_Select_An = {0x050};
+/* Interrupt Registers */
+static const cxl_p2n_reg_t CXL_PSL_DSISR_An   = {0x060};
+static const cxl_p2n_reg_t CXL_PSL_DAR_An     = {0x068};
+static const cxl_p2n_reg_t CXL_PSL_DSR_An     = {0x070};
+static const cxl_p2n_reg_t CXL_PSL_TFC_An     = {0x078};
+static const cxl_p2n_reg_t CXL_PSL_PEHandle_An = {0x080};
+static const cxl_p2n_reg_t CXL_PSL_ErrStat_An = {0x088};
+/* AFU Registers */
+static const cxl_p2n_reg_t CXL_AFU_Cntl_An    = {0x090};
+static const cxl_p2n_reg_t CXL_AFU_ERR_An     = {0x098};
+/* Work Element Descriptor */
+static const cxl_p2n_reg_t CXL_PSL_WED_An     = {0x0A0};
+/* 0x0C0:FFF Implementation Dependent Area */
+
+#define CXL_PSL_SPAP_Addr 0x0ffffffffffff000ULL
+#define CXL_PSL_SPAP_Size 0x0000000000000ff0ULL
+#define CXL_PSL_SPAP_Size_Shift 4
+#define CXL_PSL_SPAP_V    0x0000000000000001ULL
+
+/****** CXL_PSL_DLCNTL *****************************************************/
+#define CXL_PSL_DLCNTL_D (0x1ull << (63-28))
+#define CXL_PSL_DLCNTL_C (0x1ull << (63-29))
+#define CXL_PSL_DLCNTL_E (0x1ull << (63-30))
+#define CXL_PSL_DLCNTL_S (0x1ull << (63-31))
+#define CXL_PSL_DLCNTL_CE (CXL_PSL_DLCNTL_C | CXL_PSL_DLCNTL_E)
+#define CXL_PSL_DLCNTL_DCES (CXL_PSL_DLCNTL_D | CXL_PSL_DLCNTL_CE | CXL_PSL_DLCNTL_S)
+
+/****** CXL_PSL_SR_An ******************************************************/
+#define CXL_PSL_SR_An_SF  MSR_SF            /* 64bit */
+#define CXL_PSL_SR_An_TA  (1ull << (63-1))  /* Tags active,   GA1: 0 */
+#define CXL_PSL_SR_An_HV  MSR_HV            /* Hypervisor,    GA1: 0 */
+#define CXL_PSL_SR_An_PR  MSR_PR            /* Problem state, GA1: 1 */
+#define CXL_PSL_SR_An_ISL (1ull << (63-53)) /* Ignore Segment Large Page */
+#define CXL_PSL_SR_An_TC  (1ull << (63-54)) /* Page Table secondary hash */
+#define CXL_PSL_SR_An_US  (1ull << (63-56)) /* User state,    GA1: X */
+#define CXL_PSL_SR_An_SC  (1ull << (63-58)) /* Segment Table secondary hash */
+#define CXL_PSL_SR_An_R   MSR_DR            /* Relocate,      GA1: 1 */
+#define CXL_PSL_SR_An_MP  (1ull << (63-62)) /* Master Process */
+#define CXL_PSL_SR_An_LE  (1ull << (63-63)) /* Little Endian */
+
+/****** CXL_PSL_LLCMD_An ****************************************************/
+#define CXL_LLCMD_TERMINATE   0x0001000000000000ULL
+#define CXL_LLCMD_REMOVE      0x0002000000000000ULL
+#define CXL_LLCMD_SUSPEND     0x0003000000000000ULL
+#define CXL_LLCMD_RESUME      0x0004000000000000ULL
+#define CXL_LLCMD_ADD         0x0005000000000000ULL
+#define CXL_LLCMD_UPDATE      0x0006000000000000ULL
+#define CXL_LLCMD_HANDLE_MASK 0x000000000000ffffULL
+
+/****** CXL_PSL_ID_An ****************************************************/
+#define CXL_PSL_ID_An_F	(1ull << (63-31))
+#define CXL_PSL_ID_An_L	(1ull << (63-30))
+
+/****** CXL_PSL_SCNTL_An ****************************************************/
+#define CXL_PSL_SCNTL_An_CR          (0x1ull << (63-15))
+/* Programming Modes: */
+#define CXL_PSL_SCNTL_An_PM_MASK     (0xffffull << (63-31))
+#define CXL_PSL_SCNTL_An_PM_Shared   (0x0000ull << (63-31))
+#define CXL_PSL_SCNTL_An_PM_OS       (0x0001ull << (63-31))
+#define CXL_PSL_SCNTL_An_PM_Process  (0x0002ull << (63-31))
+#define CXL_PSL_SCNTL_An_PM_AFU      (0x0004ull << (63-31))
+#define CXL_PSL_SCNTL_An_PM_AFU_PBT  (0x0104ull << (63-31))
+/* Purge Status (ro) */
+#define CXL_PSL_SCNTL_An_Ps_MASK     (0x3ull << (63-39))
+#define CXL_PSL_SCNTL_An_Ps_Pending  (0x1ull << (63-39))
+#define CXL_PSL_SCNTL_An_Ps_Complete (0x3ull << (63-39))
+/* Purge */
+#define CXL_PSL_SCNTL_An_Pc          (0x1ull << (63-48))
+/* Suspend Status (ro) */
+#define CXL_PSL_SCNTL_An_Ss_MASK     (0x3ull << (63-55))
+#define CXL_PSL_SCNTL_An_Ss_Pending  (0x1ull << (63-55))
+#define CXL_PSL_SCNTL_An_Ss_Complete (0x3ull << (63-55))
+/* Suspend Control */
+#define CXL_PSL_SCNTL_An_Sc          (0x1ull << (63-63))
+
+/* AFU Slice Enable Status (ro) */
+#define CXL_AFU_Cntl_An_ES_MASK     (0x7ull << (63-2))
+#define CXL_AFU_Cntl_An_ES_Disabled (0x0ull << (63-2))
+#define CXL_AFU_Cntl_An_ES_Enabled  (0x4ull << (63-2))
+/* AFU Slice Enable */
+#define CXL_AFU_Cntl_An_E           (0x1ull << (63-3))
+/* AFU Slice Reset status (ro) */
+#define CXL_AFU_Cntl_An_RS_MASK     (0x3ull << (63-5))
+#define CXL_AFU_Cntl_An_RS_Pending  (0x1ull << (63-5))
+#define CXL_AFU_Cntl_An_RS_Complete (0x2ull << (63-5))
+/* AFU Slice Reset */
+#define CXL_AFU_Cntl_An_RA          (0x1ull << (63-7))
+
+/****** CXL_SSTP0/1_An ******************************************************/
+/* These top bits are for the segment that CONTAINS the segment table */
+#define CXL_SSTP0_An_B_SHIFT    SLB_VSID_SSIZE_SHIFT
+#define CXL_SSTP0_An_KS             (1ull << (63-2))
+#define CXL_SSTP0_An_KP             (1ull << (63-3))
+#define CXL_SSTP0_An_N              (1ull << (63-4))
+#define CXL_SSTP0_An_L              (1ull << (63-5))
+#define CXL_SSTP0_An_C              (1ull << (63-6))
+#define CXL_SSTP0_An_TA             (1ull << (63-7))
+#define CXL_SSTP0_An_LP_SHIFT                (63-9)  /* 2 Bits */
+/* And finally, the virtual address & size of the segment table: */
+#define CXL_SSTP0_An_SegTableSize_SHIFT      (63-31) /* 12 Bits */
+#define CXL_SSTP0_An_SegTableSize_MASK \
+	(((1ull << 12) - 1) << CXL_SSTP0_An_SegTableSize_SHIFT)
+#define CXL_SSTP0_An_STVA_U_MASK   ((1ull << (63-49))-1)
+#define CXL_SSTP1_An_STVA_L_MASK (~((1ull << (63-55))-1))
+#define CXL_SSTP1_An_V              (1ull << (63-63))
+
+/****** CXL_PSL_SLBIE_[An] **************************************************/
+/* write: */
+#define CXL_SLBIE_C        PPC_BIT(36)         /* Class */
+#define CXL_SLBIE_SS       PPC_BITMASK(37, 38) /* Segment Size */
+#define CXL_SLBIE_SS_SHIFT PPC_BITLSHIFT(38)
+#define CXL_SLBIE_TA       PPC_BIT(38)         /* Tags Active */
+/* read: */
+#define CXL_SLBIE_MAX      PPC_BITMASK(24, 31)
+#define CXL_SLBIE_PENDING  PPC_BITMASK(56, 63)
+
+/****** Common to all CXL_TLBIA/SLBIA_[An] **********************************/
+#define CXL_TLB_SLB_P          (1ull) /* Pending (read) */
+
+/****** Common to all CXL_TLB/SLB_IA/IE_[An] registers **********************/
+#define CXL_TLB_SLB_IQ_ALL     (0ull) /* Inv qualifier */
+#define CXL_TLB_SLB_IQ_LPID    (1ull) /* Inv qualifier */
+#define CXL_TLB_SLB_IQ_LPIDPID (3ull) /* Inv qualifier */
+
+/****** CXL_PSL_AFUSEL ******************************************************/
+#define CXL_PSL_AFUSEL_A (1ull << (63-55)) /* Adapter wide invalidates affect all AFUs */
+
+/****** CXL_PSL_DSISR_An ****************************************************/
+#define CXL_PSL_DSISR_An_DS (1ull << (63-0))  /* Segment not found */
+#define CXL_PSL_DSISR_An_DM (1ull << (63-1))  /* PTE not found (See also: M) or protection fault */
+#define CXL_PSL_DSISR_An_ST (1ull << (63-2))  /* Segment Table PTE not found */
+#define CXL_PSL_DSISR_An_UR (1ull << (63-3))  /* AURP PTE not found */
+#define CXL_PSL_DSISR_TRANS (CXL_PSL_DSISR_An_DS | CXL_PSL_DSISR_An_DM | CXL_PSL_DSISR_An_ST | CXL_PSL_DSISR_An_UR)
+#define CXL_PSL_DSISR_An_PE (1ull << (63-4))  /* PSL Error (implementation specific) */
+#define CXL_PSL_DSISR_An_AE (1ull << (63-5))  /* AFU Error */
+#define CXL_PSL_DSISR_An_OC (1ull << (63-6))  /* OS Context Warning */
+/* NOTE: Bits 32:63 are undefined if DSISR[DS] = 1 */
+#define CXL_PSL_DSISR_An_M  DSISR_NOHPTE      /* PTE not found */
+#define CXL_PSL_DSISR_An_P  DSISR_PROTFAULT   /* Storage protection violation */
+#define CXL_PSL_DSISR_An_A  (1ull << (63-37)) /* AFU lock access to write through or cache inhibited storage */
+#define CXL_PSL_DSISR_An_S  DSISR_ISSTORE     /* Access was afu_wr or afu_zero */
+#define CXL_PSL_DSISR_An_K  DSISR_KEYFAULT    /* Access not permitted by virtual page class key protection */
+
+/****** CXL_PSL_TFC_An ******************************************************/
+#define CXL_PSL_TFC_An_A  (1ull << (63-28)) /* Acknowledge non-translation fault */
+#define CXL_PSL_TFC_An_C  (1ull << (63-29)) /* Continue (abort transaction) */
+#define CXL_PSL_TFC_An_AE (1ull << (63-30)) /* Restart PSL with address error */
+#define CXL_PSL_TFC_An_R  (1ull << (63-31)) /* Restart PSL transaction */
+
+/* cxl_process_element->software_status */
+#define CXL_PE_SOFTWARE_STATE_V (1ul << (31 -  0)) /* Valid */
+#define CXL_PE_SOFTWARE_STATE_C (1ul << (31 - 29)) /* Complete */
+#define CXL_PE_SOFTWARE_STATE_S (1ul << (31 - 30)) /* Suspend */
+#define CXL_PE_SOFTWARE_STATE_T (1ul << (31 - 31)) /* Terminate */
+
+/* SPA->sw_command_status */
+#define CXL_SPA_SW_CMD_MASK         0xffff000000000000ULL
+#define CXL_SPA_SW_CMD_TERMINATE    0x0001000000000000ULL
+#define CXL_SPA_SW_CMD_REMOVE       0x0002000000000000ULL
+#define CXL_SPA_SW_CMD_SUSPEND      0x0003000000000000ULL
+#define CXL_SPA_SW_CMD_RESUME       0x0004000000000000ULL
+#define CXL_SPA_SW_CMD_ADD          0x0005000000000000ULL
+#define CXL_SPA_SW_CMD_UPDATE       0x0006000000000000ULL
+#define CXL_SPA_SW_STATE_MASK       0x0000ffff00000000ULL
+#define CXL_SPA_SW_STATE_TERMINATED 0x0000000100000000ULL
+#define CXL_SPA_SW_STATE_REMOVED    0x0000000200000000ULL
+#define CXL_SPA_SW_STATE_SUSPENDED  0x0000000300000000ULL
+#define CXL_SPA_SW_STATE_RESUMED    0x0000000400000000ULL
+#define CXL_SPA_SW_STATE_ADDED      0x0000000500000000ULL
+#define CXL_SPA_SW_STATE_UPDATED    0x0000000600000000ULL
+#define CXL_SPA_SW_PSL_ID_MASK      0x00000000ffff0000ULL
+#define CXL_SPA_SW_LINK_MASK        0x000000000000ffffULL
+
+#define CXL_MAX_SLICES 4
+#define MAX_AFU_MMIO_REGS 3
+
+#define CXL_MODE_DEDICATED   0x1
+#define CXL_MODE_DIRECTED    0x2
+#define CXL_MODE_TIME_SLICED 0x4
+#define CXL_SUPPORTED_MODES (CXL_MODE_DEDICATED | CXL_MODE_DIRECTED)
+
+enum cxl_context_status {
+	CLOSED,
+	OPENED,
+	STARTED
+};
+
+enum prefault_modes {
+	CXL_PREFAULT_NONE,
+	CXL_PREFAULT_WED,
+	CXL_PREFAULT_ALL,
+};
+
+struct cxl_sste {
+	__be64 esid_data;
+	__be64 vsid_data;
+};
+
+#define to_cxl_adapter(d) container_of(d, struct cxl, dev)
+#define to_cxl_afu(d) container_of(d, struct cxl_afu, dev)
+
+struct cxl_afu {
+	irq_hw_number_t psl_hwirq;
+	irq_hw_number_t serr_hwirq;
+	unsigned int serr_virq;
+	void __iomem *p1n_mmio;
+	void __iomem *p2n_mmio;
+	phys_addr_t psn_phys;
+	u64 pp_offset;
+	u64 pp_size;
+	void __iomem *afu_desc_mmio;
+	struct cxl *adapter;
+	struct device dev;
+	struct cdev afu_cdev_s, afu_cdev_m, afu_cdev_d;
+	struct device *chardev_s, *chardev_m, *chardev_d;
+	struct idr contexts_idr;
+	struct dentry *debugfs;
+	spinlock_t contexts_lock;
+	struct mutex spa_mutex;
+	spinlock_t afu_cntl_lock;
+
+	/*
+	 * Only the first part of the SPA is used for the process element
+	 * linked list. The only other part that software needs to worry about
+	 * is sw_command_status, which we store a separate pointer to.
+	 * Everything else in the SPA is only used by hardware
+	 */
+	struct cxl_process_element *spa;
+	__be64 *sw_command_status;
+	unsigned int spa_size;
+	int spa_order;
+	int spa_max_procs;
+	unsigned int psl_virq;
+
+	int pp_irqs;
+	int irqs_max;
+	int num_procs;
+	int max_procs_virtualised;
+	int slice;
+	int modes_supported;
+	int current_mode;
+	enum prefault_modes prefault_mode;
+	bool psa;
+	bool pp_psa;
+	bool enabled;
+};
+
+/*
+ * This is a cxl context.  If the PSL is in dedicated mode, there will be one
+ * of these per AFU.  If in AFU directed there can be lots of these.
+ */
+struct cxl_context {
+	struct cxl_afu *afu;
+
+	/* Problem state MMIO */
+	phys_addr_t psn_phys;
+	u64 psn_size;
+
+	spinlock_t sste_lock; /* Protects segment table entries */
+	struct cxl_sste *sstp;
+	u64 sstp0, sstp1;
+	unsigned int sst_size, sst_lru;
+
+	wait_queue_head_t wq;
+	struct pid *pid;
+	spinlock_t lock; /* Protects pending_irq_mask, pending_fault and fault_addr */
+	/* Only used in PR mode */
+	u64 process_token;
+
+	unsigned long *irq_bitmap; /* Accessed from IRQ context */
+	struct cxl_irq_ranges irqs;
+	u64 fault_addr;
+	u64 fault_dsisr;
+	u64 afu_err;
+
+	/*
+	 * This status and it's lock pretects start and detach context
+	 * from racing.  It also prevents detach from racing with
+	 * itself
+	 */
+	enum cxl_context_status status;
+	struct mutex status_mutex;
+
+
+	/* XXX: Is it possible to need multiple work items at once? */
+	struct work_struct fault_work;
+	u64 dsisr;
+	u64 dar;
+
+	struct cxl_process_element *elem;
+
+	int pe; /* process element handle */
+	u32 irq_count;
+	bool pe_inserted;
+	bool master;
+	bool kernel;
+	bool pending_irq;
+	bool pending_fault;
+	bool pending_afu_err;
+};
+
+struct cxl {
+	void __iomem *p1_mmio;
+	void __iomem *p2_mmio;
+	irq_hw_number_t err_hwirq;
+	unsigned int err_virq;
+	spinlock_t afu_list_lock;
+	struct cxl_afu *afu[CXL_MAX_SLICES];
+	struct device dev;
+	struct dentry *trace;
+	struct dentry *psl_err_chk;
+	struct dentry *debugfs;
+	struct bin_attribute cxl_attr;
+	int adapter_num;
+	int user_irqs;
+	u64 afu_desc_off;
+	u64 afu_desc_size;
+	u64 ps_off;
+	u64 ps_size;
+	u16 psl_rev;
+	u16 base_image;
+	u8 vsec_status;
+	u8 caia_major;
+	u8 caia_minor;
+	u8 slices;
+	bool user_image_loaded;
+	bool perst_loads_image;
+	bool perst_select_user;
+};
+
+int cxl_alloc_one_irq(struct cxl *adapter);
+void cxl_release_one_irq(struct cxl *adapter, int hwirq);
+int cxl_alloc_irq_ranges(struct cxl_irq_ranges *irqs, struct cxl *adapter, unsigned int num);
+void cxl_release_irq_ranges(struct cxl_irq_ranges *irqs, struct cxl *adapter);
+int cxl_setup_irq(struct cxl *adapter, unsigned int hwirq, unsigned int virq);
+
+/* common == phyp + powernv */
+struct cxl_process_element_common {
+	__be32 tid;
+	__be32 pid;
+	__be64 csrp;
+	__be64 aurp0;
+	__be64 aurp1;
+	__be64 sstp0;
+	__be64 sstp1;
+	__be64 amr;
+	u8     reserved3[4];
+	__be64 wed;
+} __packed;
+
+/* just powernv */
+struct cxl_process_element {
+	__be64 sr;
+	__be64 SPOffset;
+	__be64 sdr;
+	__be64 haurp;
+	__be32 ctxtime;
+	__be16 ivte_offsets[4];
+	__be16 ivte_ranges[4];
+	__be32 lpid;
+	struct cxl_process_element_common common;
+	__be32 software_state;
+} __packed;
+
+static inline void __iomem *_cxl_p1_addr(struct cxl *cxl, cxl_p1_reg_t reg)
+{
+	WARN_ON(!cpu_has_feature(CPU_FTR_HVMODE));
+	return cxl->p1_mmio + cxl_reg_off(reg);
+}
+
+#define cxl_p1_write(cxl, reg, val) \
+	out_be64(_cxl_p1_addr(cxl, reg), val)
+#define cxl_p1_read(cxl, reg) \
+	in_be64(_cxl_p1_addr(cxl, reg))
+
+static inline void __iomem *_cxl_p1n_addr(struct cxl_afu *afu, cxl_p1n_reg_t reg)
+{
+	WARN_ON(!cpu_has_feature(CPU_FTR_HVMODE));
+	return afu->p1n_mmio + cxl_reg_off(reg);
+}
+
+#define cxl_p1n_write(afu, reg, val) \
+	out_be64(_cxl_p1n_addr(afu, reg), val)
+#define cxl_p1n_read(afu, reg) \
+	in_be64(_cxl_p1n_addr(afu, reg))
+
+static inline void __iomem *_cxl_p2n_addr(struct cxl_afu *afu, cxl_p2n_reg_t reg)
+{
+	return afu->p2n_mmio + cxl_reg_off(reg);
+}
+
+#define cxl_p2n_write(afu, reg, val) \
+	out_be64(_cxl_p2n_addr(afu, reg), val)
+#define cxl_p2n_read(afu, reg) \
+	in_be64(_cxl_p2n_addr(afu, reg))
+
+struct cxl_calls {
+	void (*cxl_slbia)(struct mm_struct *mm);
+	struct module *owner;
+};
+int register_cxl_calls(struct cxl_calls *calls);
+void unregister_cxl_calls(struct cxl_calls *calls);
+
+int cxl_alloc_adapter_nr(struct cxl *adapter);
+void cxl_remove_adapter_nr(struct cxl *adapter);
+
+int cxl_file_init(void);
+void cxl_file_exit(void);
+int cxl_register_adapter(struct cxl *adapter);
+int cxl_register_afu(struct cxl_afu *afu);
+int cxl_chardev_d_afu_add(struct cxl_afu *afu);
+int cxl_chardev_m_afu_add(struct cxl_afu *afu);
+int cxl_chardev_s_afu_add(struct cxl_afu *afu);
+void cxl_chardev_afu_remove(struct cxl_afu *afu);
+
+void cxl_context_detach_all(struct cxl_afu *afu);
+void cxl_context_free(struct cxl_context *ctx);
+void cxl_context_detach(struct cxl_context *ctx);
+
+int cxl_sysfs_adapter_add(struct cxl *adapter);
+void cxl_sysfs_adapter_remove(struct cxl *adapter);
+int cxl_sysfs_afu_add(struct cxl_afu *afu);
+void cxl_sysfs_afu_remove(struct cxl_afu *afu);
+int cxl_sysfs_afu_m_add(struct cxl_afu *afu);
+void cxl_sysfs_afu_m_remove(struct cxl_afu *afu);
+
+int cxl_afu_activate_mode(struct cxl_afu *afu, int mode);
+int _cxl_afu_deactivate_mode(struct cxl_afu *afu, int mode);
+int cxl_afu_deactivate_mode(struct cxl_afu *afu);
+int cxl_afu_select_best_mode(struct cxl_afu *afu);
+
+unsigned int cxl_map_irq(struct cxl *adapter, irq_hw_number_t hwirq,
+		         irq_handler_t handler, void *cookie);
+void cxl_unmap_irq(unsigned int virq, void *cookie);
+int cxl_register_psl_irq(struct cxl_afu *afu);
+void cxl_release_psl_irq(struct cxl_afu *afu);
+int cxl_register_psl_err_irq(struct cxl *adapter);
+void cxl_release_psl_err_irq(struct cxl *adapter);
+int cxl_register_serr_irq(struct cxl_afu *afu);
+void cxl_release_serr_irq(struct cxl_afu *afu);
+int afu_register_irqs(struct cxl_context *ctx, u32 count);
+void afu_release_irqs(struct cxl_context *ctx);
+irqreturn_t cxl_slice_irq_err(int irq, void *data);
+
+int cxl_debugfs_init(void);
+void cxl_debugfs_exit(void);
+int cxl_debugfs_adapter_add(struct cxl *adapter);
+void cxl_debugfs_adapter_remove(struct cxl *adapter);
+int cxl_debugfs_afu_add(struct cxl_afu *afu);
+void cxl_debugfs_afu_remove(struct cxl_afu *afu);
+
+void cxl_handle_fault(struct work_struct *work);
+void cxl_prefault(struct cxl_context *ctx, u64 wed);
+
+struct cxl *get_cxl_adapter(int num);
+int cxl_alloc_sst(struct cxl_context *ctx);
+
+void init_cxl_native(void);
+
+struct cxl_context *cxl_context_alloc(void);
+int cxl_context_init(struct cxl_context *ctx, struct cxl_afu *afu, bool master);
+void cxl_context_free(struct cxl_context *ctx);
+int cxl_context_iomap(struct cxl_context *ctx, struct vm_area_struct *vma);
+
+/* This matches the layout of the H_COLLECT_CA_INT_INFO retbuf */
+struct cxl_irq_info {
+	u64 dsisr;
+	u64 dar;
+	u64 dsr;
+	u32 pid;
+	u32 tid;
+	u64 afu_err;
+	u64 errstat;
+	u64 padding[3]; /* to match the expected retbuf size for plpar_hcall9 */
+};
+
+int cxl_attach_process(struct cxl_context *ctx, bool kernel, u64 wed,
+			    u64 amr);
+int cxl_detach_process(struct cxl_context *ctx);
+
+int cxl_get_irq(struct cxl_context *ctx, struct cxl_irq_info *info);
+int cxl_ack_irq(struct cxl_context *ctx, u64 tfc, u64 psl_reset_mask);
+
+int cxl_check_error(struct cxl_afu *afu);
+int cxl_afu_slbia(struct cxl_afu *afu);
+int cxl_tlb_slb_invalidate(struct cxl *adapter);
+int cxl_afu_disable(struct cxl_afu *afu);
+int cxl_afu_reset(struct cxl_afu *afu);
+int cxl_psl_purge(struct cxl_afu *afu);
+
+void cxl_stop_trace(struct cxl *cxl);
+
+extern struct pci_driver cxl_pci_driver;
+
+#endif
diff --git a/drivers/misc/cxl/debugfs.c b/drivers/misc/cxl/debugfs.c
new file mode 100644
index 000000000000..825c412580bc
--- /dev/null
+++ b/drivers/misc/cxl/debugfs.c
@@ -0,0 +1,132 @@
+/*
+ * Copyright 2014 IBM Corp.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/debugfs.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+
+#include "cxl.h"
+
+static struct dentry *cxl_debugfs;
+
+void cxl_stop_trace(struct cxl *adapter)
+{
+	int slice;
+
+	/* Stop the trace */
+	cxl_p1_write(adapter, CXL_PSL_TRACE, 0x8000000000000017LL);
+
+	/* Stop the slice traces */
+	spin_lock(&adapter->afu_list_lock);
+	for (slice = 0; slice < adapter->slices; slice++) {
+		if (adapter->afu[slice])
+			cxl_p1n_write(adapter->afu[slice], CXL_PSL_SLICE_TRACE, 0x8000000000000000LL);
+	}
+	spin_unlock(&adapter->afu_list_lock);
+}
+
+/* Helpers to export CXL mmaped IO registers via debugfs */
+static int debugfs_io_u64_get(void *data, u64 *val)
+{
+	*val = in_be64((u64 __iomem *)data);
+	return 0;
+}
+
+static int debugfs_io_u64_set(void *data, u64 val)
+{
+	out_be64((u64 __iomem *)data, val);
+	return 0;
+}
+DEFINE_SIMPLE_ATTRIBUTE(fops_io_x64, debugfs_io_u64_get, debugfs_io_u64_set, "0x%016llx\n");
+
+static struct dentry *debugfs_create_io_x64(const char *name, umode_t mode,
+					    struct dentry *parent, u64 __iomem *value)
+{
+	return debugfs_create_file(name, mode, parent, (void *)value, &fops_io_x64);
+}
+
+int cxl_debugfs_adapter_add(struct cxl *adapter)
+{
+	struct dentry *dir;
+	char buf[32];
+
+	if (!cxl_debugfs)
+		return -ENODEV;
+
+	snprintf(buf, 32, "card%i", adapter->adapter_num);
+	dir = debugfs_create_dir(buf, cxl_debugfs);
+	if (IS_ERR(dir))
+		return PTR_ERR(dir);
+	adapter->debugfs = dir;
+
+	debugfs_create_io_x64("fir1",     S_IRUSR, dir, _cxl_p1_addr(adapter, CXL_PSL_FIR1));
+	debugfs_create_io_x64("fir2",     S_IRUSR, dir, _cxl_p1_addr(adapter, CXL_PSL_FIR2));
+	debugfs_create_io_x64("fir_cntl", S_IRUSR, dir, _cxl_p1_addr(adapter, CXL_PSL_FIR_CNTL));
+	debugfs_create_io_x64("err_ivte", S_IRUSR, dir, _cxl_p1_addr(adapter, CXL_PSL_ErrIVTE));
+
+	debugfs_create_io_x64("trace", S_IRUSR | S_IWUSR, dir, _cxl_p1_addr(adapter, CXL_PSL_TRACE));
+
+	return 0;
+}
+
+void cxl_debugfs_adapter_remove(struct cxl *adapter)
+{
+	debugfs_remove_recursive(adapter->debugfs);
+}
+
+int cxl_debugfs_afu_add(struct cxl_afu *afu)
+{
+	struct dentry *dir;
+	char buf[32];
+
+	if (!afu->adapter->debugfs)
+		return -ENODEV;
+
+	snprintf(buf, 32, "psl%i.%i", afu->adapter->adapter_num, afu->slice);
+	dir = debugfs_create_dir(buf, afu->adapter->debugfs);
+	if (IS_ERR(dir))
+		return PTR_ERR(dir);
+	afu->debugfs = dir;
+
+	debugfs_create_io_x64("fir",        S_IRUSR, dir, _cxl_p1n_addr(afu, CXL_PSL_FIR_SLICE_An));
+	debugfs_create_io_x64("serr",       S_IRUSR, dir, _cxl_p1n_addr(afu, CXL_PSL_SERR_An));
+	debugfs_create_io_x64("afu_debug",  S_IRUSR, dir, _cxl_p1n_addr(afu, CXL_AFU_DEBUG_An));
+	debugfs_create_io_x64("sr",         S_IRUSR, dir, _cxl_p1n_addr(afu, CXL_PSL_SR_An));
+
+	debugfs_create_io_x64("dsisr",      S_IRUSR, dir, _cxl_p2n_addr(afu, CXL_PSL_DSISR_An));
+	debugfs_create_io_x64("dar",        S_IRUSR, dir, _cxl_p2n_addr(afu, CXL_PSL_DAR_An));
+	debugfs_create_io_x64("sstp0",      S_IRUSR, d