George Zhang
2012-Aug-30 16:42 UTC
[PATCH 09/11] vmci_resource.patch: VMCI resource hash table implementation.
Signed-off-by: George Zhang <georgezhang at vmware.com>
---
drivers/misc/vmw_vmci/vmci_resource.c | 190 +++++++++++++++++++++++++++++++++
drivers/misc/vmw_vmci/vmci_resource.h | 59 ++++++++++
2 files changed, 249 insertions(+), 0 deletions(-)
create mode 100644 drivers/misc/vmw_vmci/vmci_resource.c
create mode 100644 drivers/misc/vmw_vmci/vmci_resource.h
diff --git a/drivers/misc/vmw_vmci/vmci_resource.c
b/drivers/misc/vmw_vmci/vmci_resource.c
new file mode 100644
index 0000000..2ea3594
--- /dev/null
+++ b/drivers/misc/vmw_vmci/vmci_resource.c
@@ -0,0 +1,190 @@
+/*
+ * VMware VMCI Driver
+ *
+ * Copyright (C) 2012 VMware, Inc. All rights reserved.
+ *
+ * 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 version 2 and no later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * for more details.
+ */
+
+#include <linux/vmw_vmci_defs.h>
+
+#include "vmci_common_int.h"
+#include "vmci_hash_table.h"
+#include "vmci_resource.h"
+#include "vmci_driver.h"
+
+/* 0 through VMCI_RESERVED_RESOURCE_ID_MAX are reserved. */
+static uint32_t resourceID = VMCI_RESERVED_RESOURCE_ID_MAX + 1;
+static spinlock_t resourceIdLock;
+static struct vmci_hash_table *resourceTable;
+
+/*
+ * Initializes the VMCI Resource Access Control API. Creates a hashtable
+ * to hold all resources, and registers vectors and callbacks for
+ * hypercalls.
+ */
+int __init vmci_resource_init(void)
+{
+ spin_lock_init(&resourceIdLock);
+
+ resourceTable = vmci_hash_create(128);
+ if (resourceTable == NULL) {
+ pr_warn("Failed creating a resource hash table.");
+ return VMCI_ERROR_NO_MEM;
+ }
+
+ return VMCI_SUCCESS;
+}
+
+void vmci_resource_exit(void)
+{
+ if (resourceTable)
+ vmci_hash_destroy(resourceTable);
+}
+
+/*
+ * Return resource ID. The first VMCI_RESERVED_RESOURCE_ID_MAX are
+ * reserved so we start from its value + 1. Returns
+ * VMCI resource id on success, VMCI_INVALID_ID on failure.
+ */
+uint32_t vmci_resource_get_id(uint32_t contextID)
+{
+ uint32_t oldRID = resourceID;
+ uint32_t currentRID;
+ bool foundRID = false;
+
+ /*
+ * Generate a unique resource ID. Keep on trying until we wrap around
+ * in the RID space.
+ */
+ ASSERT(oldRID > VMCI_RESERVED_RESOURCE_ID_MAX);
+
+ do {
+ struct vmci_handle handle;
+
+ spin_lock(&resourceIdLock);
+ currentRID = resourceID;
+ handle = vmci_make_handle(contextID, currentRID);
+ resourceID++;
+ if (unlikely(resourceID == VMCI_INVALID_ID)) {
+ /* Skip the reserved rids. */
+
+ resourceID = VMCI_RESERVED_RESOURCE_ID_MAX + 1;
+ }
+ spin_unlock(&resourceIdLock);
+ foundRID = !vmci_hash_exists(resourceTable, handle);
+ } while (!foundRID && resourceID != oldRID);
+
+ return (unlikely(!foundRID)) ? VMCI_INVALID_ID : currentRID;
+}
+
+int vmci_resource_add(struct vmci_resource *resource,
+ enum vmci_resource_type resourceType,
+ struct vmci_handle resourceHandle,
+ VMCIResourceFreeCB containerFreeCB,
+ void *containerObject)
+{
+ int result;
+
+ ASSERT(resource);
+
+ if (VMCI_HANDLE_EQUAL(resourceHandle, VMCI_INVALID_HANDLE)) {
+ pr_devel("Invalid argument resource
(handle=0x%x:0x%x)",
+ resourceHandle.context, resourceHandle.resource);
+ return VMCI_ERROR_INVALID_ARGS;
+ }
+
+ vmci_hash_init_entry(&resource->hashEntry, resourceHandle);
+ resource->type = resourceType;
+ resource->containerFreeCB = containerFreeCB;
+ resource->containerObject = containerObject;
+
+ /* Add resource to hashtable. */
+ result = vmci_hash_add(resourceTable, &resource->hashEntry);
+ if (result != VMCI_SUCCESS) {
+ pr_devel("Failed to add entry to hash table " \
+ "(result=%d).", result);
+ return result;
+ }
+
+ return result;
+}
+
+void vmci_resource_remove(struct vmci_handle resourceHandle,
+ enum vmci_resource_type resourceType)
+{
+ struct vmci_resource *resource +
vmci_resource_get(resourceHandle, resourceType);
+
+ if (resource == NULL)
+ return;
+
+ /* Remove resource from hashtable. */
+ vmci_hash_remove(resourceTable, &resource->hashEntry);
+
+ vmci_resource_release(resource);
+ /* resource could be freed by now. */
+}
+
+struct vmci_resource *vmci_resource_get(struct vmci_handle resourceHandle,
+ enum vmci_resource_type resourceType)
+{
+ struct vmci_resource *resource;
+ struct vmci_hash_entry *entry +
vmci_hash_get(resourceTable, resourceHandle);
+
+ if (entry == NULL)
+ return NULL;
+
+ resource = container_of(entry, struct vmci_resource, hashEntry);
+ if (resourceType == VMCI_RESOURCE_TYPE_ANY ||
+ resource->type == resourceType)
+ return resource;
+
+ vmci_hash_release(resourceTable, entry);
+ return NULL;
+}
+
+/*
+ * Hold the given resource. This will hold the hashtable entry. This
+ * is like doing a Get() but without having to lookup the resource by
+ * handle.
+ */
+void vmci_resource_hold(struct vmci_resource *resource)
+{
+ ASSERT(resource);
+ vmci_hash_hold(resourceTable, &resource->hashEntry);
+}
+
+/*
+ * resource's containerFreeCB will get called if last reference.
+ */
+int vmci_resource_release(struct vmci_resource *resource)
+{
+ int result;
+
+ ASSERT(resource);
+
+ result = vmci_hash_release(resourceTable, &resource->hashEntry);
+ if (result == VMCI_SUCCESS_ENTRY_DEAD &&
resource->containerFreeCB)
+ resource->containerFreeCB(resource->containerObject);
+
+ /*
+ * We propagate the information back to caller in case it wants to know
+ * whether entry was freed.
+ */
+ return result;
+}
+
+struct vmci_handle vmci_resource_handle(struct vmci_resource *resource)
+{
+ ASSERT(resource);
+ return resource->hashEntry.handle;
+}
diff --git a/drivers/misc/vmw_vmci/vmci_resource.h
b/drivers/misc/vmw_vmci/vmci_resource.h
new file mode 100644
index 0000000..52e0e0f
--- /dev/null
+++ b/drivers/misc/vmw_vmci/vmci_resource.h
@@ -0,0 +1,59 @@
+/*
+ * VMware VMCI Driver
+ *
+ * Copyright (C) 2012 VMware, Inc. All rights reserved.
+ *
+ * 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 version 2 and no later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * for more details.
+ */
+
+#ifndef _VMCI_RESOURCE_H_
+#define _VMCI_RESOURCE_H_
+
+#include <linux/vmw_vmci_defs.h>
+#include <linux/types.h>
+
+#include "vmci_hash_table.h"
+#include "vmci_context.h"
+
+typedef void (*VMCIResourceFreeCB) (void *resource);
+
+enum vmci_resource_type {
+ VMCI_RESOURCE_TYPE_ANY,
+ VMCI_RESOURCE_TYPE_API,
+ VMCI_RESOURCE_TYPE_GROUP,
+ VMCI_RESOURCE_TYPE_DATAGRAM,
+ VMCI_RESOURCE_TYPE_DOORBELL,
+};
+
+struct vmci_resource {
+ struct vmci_hash_entry hashEntry;
+ enum vmci_resource_type type;
+ /* Callback to free container object when refCount is 0. */
+ VMCIResourceFreeCB containerFreeCB;
+ void *containerObject; /* Container object reference. */
+};
+
+int vmci_resource_init(void);
+void vmci_resource_exit(void);
+uint32_t vmci_resource_get_id(uint32_t contextID);
+int vmci_resource_add(struct vmci_resource *resource,
+ enum vmci_resource_type resourceType,
+ struct vmci_handle resourceHandle,
+ VMCIResourceFreeCB containerFreeCB,
+ void *containerObject);
+void vmci_resource_remove(struct vmci_handle resourceHandle,
+ enum vmci_resource_type resourceType);
+struct vmci_resource *vmci_resource_get(struct vmci_handle resourceHandle,
+ enum vmci_resource_type resourceType);
+void vmci_resource_hold(struct vmci_resource *resource);
+int vmci_resource_release(struct vmci_resource *resource);
+struct vmci_handle vmci_resource_handle(struct vmci_resource *resource);
+
+#endif /* _VMCI_RESOURCE_H_ */
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