1 files changed, 75 insertions, 21 deletions

diff --git a/drivers/misc/cxl/context.c b/drivers/misc/cxl/context.c
index cca472109135..d1b55fe62817 100644
--- a/drivers/misc/cxl/context.c
+++ b/drivers/misc/cxl/context.c
@@ -34,7 +34,8 @@ struct cxl_context *cxl_context_alloc(void)
 /*
  * Initialises a CXL context.
  */
-int cxl_context_init(struct cxl_context *ctx, struct cxl_afu *afu, bool master)
+int cxl_context_init(struct cxl_context *ctx, struct cxl_afu *afu, bool master,
+		     struct address_space *mapping)
 {
 	int i;
 
@@ -42,6 +43,8 @@ int cxl_context_init(struct cxl_context *ctx, struct cxl_afu *afu, bool master)
 	ctx->afu = afu;
 	ctx->master = master;
 	ctx->pid = NULL; /* Set in start work ioctl */
+	mutex_init(&ctx->mapping_lock);
+	ctx->mapping = mapping;
 
 	/*
 	 * Allocate the segment table before we put it in the IDR so that we
@@ -82,12 +85,12 @@ int cxl_context_init(struct cxl_context *ctx, struct cxl_afu *afu, bool master)
 	 * Allocating IDR! We better make sure everything's setup that
 	 * dereferences from it.
 	 */
+	mutex_lock(&afu->contexts_lock);
 	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();
+	mutex_unlock(&afu->contexts_lock);
 	if (i < 0)
 		return i;
 
@@ -97,6 +100,46 @@ int cxl_context_init(struct cxl_context *ctx, struct cxl_afu *afu, bool master)
 	return 0;
 }
 
+static int cxl_mmap_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
+{
+	struct cxl_context *ctx = vma->vm_file->private_data;
+	unsigned long address = (unsigned long)vmf->virtual_address;
+	u64 area, offset;
+
+	offset = vmf->pgoff << PAGE_SHIFT;
+
+	pr_devel("%s: pe: %i address: 0x%lx offset: 0x%llx\n",
+			__func__, ctx->pe, 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__);
+		return VM_FAULT_SIGBUS;
+	}
+
+	vm_insert_pfn(vma, address, (area + offset) >> PAGE_SHIFT);
+
+	mutex_unlock(&ctx->status_mutex);
+
+	return VM_FAULT_NOPAGE;
+}
+
+static const struct vm_operations_struct cxl_mmap_vmops = {
+	.fault = cxl_mmap_fault,
+};
+
 /*
  * Map a per-context mmio space into the given vma.
  */
@@ -105,26 +148,25 @@ 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);
-	}
+	if (ctx->afu->current_mode != CXL_MODE_DEDICATED) {
+		/* 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;
+		}
 
-	/* 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;
 	}
 
-	/* 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);
-	return vm_iomap_memory(vma, ctx->psn_phys, len);
+	vma->vm_ops = &cxl_mmap_vmops;
+	return 0;
 }
 
 /*
@@ -168,21 +210,33 @@ 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)
+	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
 		 */
 		__detach_context(ctx);
-	rcu_read_unlock();
+
+		/*
+		 * 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);
 }
 
 void cxl_context_free(struct cxl_context *ctx)
 {
-	spin_lock(&ctx->afu->contexts_lock);
+	mutex_lock(&ctx->afu->contexts_lock);
 	idr_remove(&ctx->afu->contexts_idr, ctx->pe);
-	spin_unlock(&ctx->afu->contexts_lock);
+	mutex_unlock(&ctx->afu->contexts_lock);
 	synchronize_rcu();
 
 	free_page((u64)ctx->sstp);