v4.19.13 snapshot.
diff --git a/drivers/misc/cxl/context.c b/drivers/misc/cxl/context.c
new file mode 100644
index 0000000..5fe529b
--- /dev/null
+++ b/drivers/misc/cxl/context.c
@@ -0,0 +1,366 @@
+/*
+ * 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 <linux/sched/mm.h>
+#include <linux/mmu_context.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;
+
+ ctx->afu = afu;
+ ctx->master = master;
+ ctx->pid = NULL; /* Set in start work ioctl */
+ mutex_init(&ctx->mapping_lock);
+ ctx->mapping = NULL;
+ ctx->tidr = 0;
+ ctx->assign_tidr = false;
+
+ if (cxl_is_power8()) {
+ spin_lock_init(&ctx->sste_lock);
+
+ /*
+ * 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;
+
+ INIT_LIST_HEAD(&ctx->irq_names);
+
+ /*
+ * 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.
+ */
+ mutex_lock(&afu->contexts_lock);
+ idr_preload(GFP_KERNEL);
+ i = idr_alloc(&ctx->afu->contexts_idr, ctx, 0,
+ ctx->afu->num_procs, GFP_NOWAIT);
+ idr_preload_end();
+ mutex_unlock(&afu->contexts_lock);
+ if (i < 0)
+ return i;
+
+ ctx->pe = i;
+ if (cpu_has_feature(CPU_FTR_HVMODE)) {
+ ctx->elem = &ctx->afu->native->spa[i];
+ ctx->external_pe = ctx->pe;
+ } else {
+ ctx->external_pe = -1; /* assigned when attaching */
+ }
+ ctx->pe_inserted = false;
+
+ /*
+ * take a ref on the afu so that it stays alive at-least till
+ * this context is reclaimed inside reclaim_ctx.
+ */
+ cxl_afu_get(afu);
+ return 0;
+}
+
+void cxl_context_set_mapping(struct cxl_context *ctx,
+ struct address_space *mapping)
+{
+ mutex_lock(&ctx->mapping_lock);
+ ctx->mapping = mapping;
+ mutex_unlock(&ctx->mapping_lock);
+}
+
+static vm_fault_t cxl_mmap_fault(struct vm_fault *vmf)
+{
+ struct vm_area_struct *vma = vmf->vma;
+ struct cxl_context *ctx = vma->vm_file->private_data;
+ u64 area, offset;
+ vm_fault_t ret;
+
+ offset = vmf->pgoff << PAGE_SHIFT;
+
+ pr_devel("%s: pe: %i address: 0x%lx offset: 0x%llx\n",
+ __func__, ctx->pe, vmf->address, offset);
+
+ if (ctx->afu->current_mode == CXL_MODE_DEDICATED) {
+ area = ctx->afu->psn_phys;
+ if (offset >= ctx->afu->adapter->ps_size)
+ return VM_FAULT_SIGBUS;
+ } else {
+ area = ctx->psn_phys;
+ if (offset >= ctx->psn_size)
+ return VM_FAULT_SIGBUS;
+ }
+
+ mutex_lock(&ctx->status_mutex);
+
+ if (ctx->status != STARTED) {
+ mutex_unlock(&ctx->status_mutex);
+ pr_devel("%s: Context not started, failing problem state access\n", __func__);
+ if (ctx->mmio_err_ff) {
+ if (!ctx->ff_page) {
+ ctx->ff_page = alloc_page(GFP_USER);
+ if (!ctx->ff_page)
+ return VM_FAULT_OOM;
+ memset(page_address(ctx->ff_page), 0xff, PAGE_SIZE);
+ }
+ get_page(ctx->ff_page);
+ vmf->page = ctx->ff_page;
+ vma->vm_page_prot = pgprot_cached(vma->vm_page_prot);
+ return 0;
+ }
+ return VM_FAULT_SIGBUS;
+ }
+
+ ret = vmf_insert_pfn(vma, vmf->address, (area + offset) >> PAGE_SHIFT);
+
+ mutex_unlock(&ctx->status_mutex);
+
+ return ret;
+}
+
+static const struct vm_operations_struct cxl_mmap_vmops = {
+ .fault = cxl_mmap_fault,
+};
+
+/*
+ * Map a per-context mmio space into the given vma.
+ */
+int cxl_context_iomap(struct cxl_context *ctx, struct vm_area_struct *vma)
+{
+ u64 start = vma->vm_pgoff << PAGE_SHIFT;
+ u64 len = vma->vm_end - vma->vm_start;
+
+ if (ctx->afu->current_mode == CXL_MODE_DEDICATED) {
+ if (start + len > ctx->afu->adapter->ps_size)
+ return -EINVAL;
+
+ if (cxl_is_power9()) {
+ /*
+ * Make sure there is a valid problem state
+ * area space for this AFU.
+ */
+ if (ctx->master && !ctx->afu->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;
+ }
+ } else {
+ if (start + len > ctx->psn_size)
+ return -EINVAL;
+
+ /* 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_flags |= VM_IO | VM_PFNMAP;
+ vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
+ vma->vm_ops = &cxl_mmap_vmops;
+ return 0;
+}
+
+/*
+ * 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.
+ */
+int __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 -EBUSY;
+
+ /* Only warn if we detached while the link was OK.
+ * If detach fails when hw is down, we don't care.
+ */
+ WARN_ON(cxl_ops->detach_process(ctx) &&
+ cxl_ops->link_ok(ctx->afu->adapter, ctx->afu));
+ flush_work(&ctx->fault_work); /* Only needed for dedicated process */
+
+ /*
+ * Wait until no further interrupts are presented by the PSL
+ * for this context.
+ */
+ if (cxl_ops->irq_wait)
+ cxl_ops->irq_wait(ctx);
+
+ /* release the reference to the group leader and mm handling pid */
+ put_pid(ctx->pid);
+
+ cxl_ctx_put();
+
+ /* Decrease the attached context count on the adapter */
+ cxl_adapter_context_put(ctx->afu->adapter);
+
+ /* Decrease the mm count on the context */
+ cxl_context_mm_count_put(ctx);
+ if (ctx->mm)
+ mm_context_remove_copro(ctx->mm);
+ ctx->mm = NULL;
+
+ return 0;
+}
+
+/*
+ * 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)
+{
+ int rc;
+
+ rc = __detach_context(ctx);
+ if (rc)
+ return;
+
+ afu_release_irqs(ctx, ctx);
+ wake_up_all(&ctx->wq);
+}
+
+/*
+ * Detach all contexts on the given AFU.
+ */
+void cxl_context_detach_all(struct cxl_afu *afu)
+{
+ struct cxl_context *ctx;
+ int tmp;
+
+ mutex_lock(&afu->contexts_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
+ */
+ cxl_context_detach(ctx);
+
+ /*
+ * We are force detaching - remove any active PSA mappings so
+ * userspace cannot interfere with the card if it comes back.
+ * Easiest way to exercise this is to unbind and rebind the
+ * driver via sysfs while it is in use.
+ */
+ mutex_lock(&ctx->mapping_lock);
+ if (ctx->mapping)
+ unmap_mapping_range(ctx->mapping, 0, 0, 1);
+ mutex_unlock(&ctx->mapping_lock);
+ }
+ mutex_unlock(&afu->contexts_lock);
+}
+
+static void reclaim_ctx(struct rcu_head *rcu)
+{
+ struct cxl_context *ctx = container_of(rcu, struct cxl_context, rcu);
+
+ if (cxl_is_power8())
+ free_page((u64)ctx->sstp);
+ if (ctx->ff_page)
+ __free_page(ctx->ff_page);
+ ctx->sstp = NULL;
+
+ kfree(ctx->irq_bitmap);
+
+ /* Drop ref to the afu device taken during cxl_context_init */
+ cxl_afu_put(ctx->afu);
+
+ kfree(ctx);
+}
+
+void cxl_context_free(struct cxl_context *ctx)
+{
+ if (ctx->kernelapi && ctx->mapping)
+ cxl_release_mapping(ctx);
+ mutex_lock(&ctx->afu->contexts_lock);
+ idr_remove(&ctx->afu->contexts_idr, ctx->pe);
+ mutex_unlock(&ctx->afu->contexts_lock);
+ call_rcu(&ctx->rcu, reclaim_ctx);
+}
+
+void cxl_context_mm_count_get(struct cxl_context *ctx)
+{
+ if (ctx->mm)
+ atomic_inc(&ctx->mm->mm_count);
+}
+
+void cxl_context_mm_count_put(struct cxl_context *ctx)
+{
+ if (ctx->mm)
+ mmdrop(ctx->mm);
+}