[PATCH 06/10] VMCI: handle array implementation.

George Zhang
2012-10-16T00:29:20Z

VMCI handle code adds support for dynamic arrays that will grow if they need to.

Signed-off-by: George Zhang <georgezhang@vmware.com>
---
drivers/misc/vmw_vmci/vmci_handle_array.c | 162 +++++++++++++++++++++++++++++
drivers/misc/vmw_vmci/vmci_handle_array.h | 46 ++++++++
2 files changed, 208 insertions(+), 0 deletions(-)
create mode 100644 drivers/misc/vmw_vmci/vmci_handle_array.c
create mode 100644 drivers/misc/vmw_vmci/vmci_handle_array.h

diff --git a/drivers/misc/vmw_vmci/vmci_handle_array.c b/drivers/misc/vmw_vmci/vmci_handle_array.c
new file mode 100644
index 0000000..c7db831
--- /dev/null
+++ b/drivers/misc/vmw_vmci/vmci_handle_array.c
@@ -0,0 +1,162 @@
+/*
+ * 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/slab.h>
+#include "vmci_handle_array.h"
+
+static size_t handle_arr_calc_size(size_t capacity)
+{
+ return sizeof(struct vmci_handle_arr) +
+ capacity * sizeof(struct vmci_handle);
+}
+
+struct vmci_handle_arr *vmci_handle_arr_create(size_t capacity)
+{
+ struct vmci_handle_arr *array;
+
+ if (capacity == 0)
+ capacity = VMCI_HANDLE_ARRAY_DEFAULT_SIZE;
+
+ array = kmalloc(handle_arr_calc_size(capacity), GFP_ATOMIC);
+ if (!array)
+ return NULL;
+
+ array->capacity = capacity;
+ array->size = 0;
+
+ return array;
+}
+
+void vmci_handle_arr_destroy(struct vmci_handle_arr *array)
+{
+ kfree(array);
+}
+
+void vmci_handle_arr_append_entry(struct vmci_handle_arr **array_ptr,
+ struct vmci_handle handle)
+{
+ struct vmci_handle_arr *array;
+
+ BUG_ON(!array_ptr || !*array_ptr);
+ array = *array_ptr;
+
+ if (unlikely(array->size >= array->capacity)) {
+ /* reallocate. */
+ struct vmci_handle_arr *new_array;
+ size_t new_capacity = array->capacity * VMCI_ARR_CAP_MULT;
+ size_t new_size = handle_arr_calc_size(new_capacity);
+
+ new_array = krealloc(array, new_size, GFP_ATOMIC);
+ if (!new_array)
+ return;
+
+ new_array->capacity = new_capacity;
+ *array_ptr = array = new_array;
+ }
+
+ array->entries[array->size] = handle;
+ array->size++;
+}
+
+/*
+ * Handle that was removed, VMCI_INVALID_HANDLE if entry not found.
+ */
+struct vmci_handle vmci_handle_arr_remove_entry(struct vmci_handle_arr *array,
+ struct vmci_handle entry_handle)
+{
+ struct vmci_handle handle = VMCI_INVALID_HANDLE;
+ size_t i;
+
+ BUG_ON(!array);
+
+ for (i = 0; i < array->size; i++) {
+ if (VMCI_HANDLE_EQUAL(array->entries[i], entry_handle)) {
+ handle = array->entries[i];
+ array->size--;
+ array->entries[i] = array->entries[array->size];
+ array->entries[array->size] = VMCI_INVALID_HANDLE;
+ break;
+ }
+ }
+
+ return handle;
+}
+
+/*
+ * Handle that was removed, VMCI_INVALID_HANDLE if array was empty.
+ */
+struct vmci_handle vmci_handle_arr_remove_tail(struct vmci_handle_arr *array)
+{
+ struct vmci_handle handle = VMCI_INVALID_HANDLE;
+
+ BUG_ON(!array);
+
+ if (array->size) {
+ array->size--;
+ handle = array->entries[array->size];
+ array->entries[array->size] = VMCI_INVALID_HANDLE;
+ }
+
+ return handle;
+}
+
+/*
+ * Handle at given index, VMCI_INVALID_HANDLE if invalid index.
+ */
+struct vmci_handle
+vmci_handle_arr_get_entry(const struct vmci_handle_arr *array, size_t index)
+{
+ BUG_ON(!array);
+
+ if (unlikely(index >= array->size))
+ return VMCI_INVALID_HANDLE;
+
+ return array->entries[index];
+}
+
+size_t vmci_handle_arr_get_size(const struct vmci_handle_arr *array)
+{
+ BUG_ON(!array);
+
+ return array->size;
+}
+
+bool vmci_handle_arr_has_entry(const struct vmci_handle_arr *array,
+ struct vmci_handle entry_handle)
+{
+ size_t i;
+
+ BUG_ON(!array);
+
+ for (i = 0; i < array->size; i++)
+ if (VMCI_HANDLE_EQUAL(array->entries[i], entry_handle))
+ return true;
+
+ return false;
+}
+
+/*
+ * NULL if the array is empty. Otherwise, a pointer to the array
+ * of VMCI handles in the handle array.
+ */
+struct vmci_handle *vmci_handle_arr_get_handles(struct vmci_handle_arr *array)
+{
+ BUG_ON(!array);
+
+ if (array->size)
+ return array->entries;
+
+ return NULL;
+}
diff --git a/drivers/misc/vmw_vmci/vmci_handle_array.h b/drivers/misc/vmw_vmci/vmci_handle_array.h
new file mode 100644
index 0000000..37d1214
--- /dev/null
+++ b/drivers/misc/vmw_vmci/vmci_handle_array.h
@@ -0,0 +1,46 @@
+/*
+ * 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_HANDLE_ARRAY_H_
+#define _VMCI_HANDLE_ARRAY_H_
+
+#include <linux/vmw_vmci_defs.h>
+#include <linux/types.h>
+
+#define VMCI_HANDLE_ARRAY_DEFAULT_SIZE 4
+#define VMCI_ARR_CAP_MULT 2 /* Array capacity multiplier */
+
+struct vmci_handle_arr {
+ size_t capacity;
+ size_t size;
+ struct vmci_handle entries[];
+};
+
+struct vmci_handle_arr *vmci_handle_arr_create(size_t capacity);
+void vmci_handle_arr_destroy(struct vmci_handle_arr *array);
+void vmci_handle_arr_append_entry(struct vmci_handle_arr **array_ptr,
+ struct vmci_handle handle);
+struct vmci_handle vmci_handle_arr_remove_entry(struct vmci_handle_arr *array,
+ struct vmci_handle
+ entry_handle);
+struct vmci_handle vmci_handle_arr_remove_tail(struct vmci_handle_arr *array);
+struct vmci_handle
+vmci_handle_arr_get_entry(const struct vmci_handle_arr *array, size_t index);
+size_t vmci_handle_arr_get_size(const struct vmci_handle_arr *array);
+bool vmci_handle_arr_has_entry(const struct vmci_handle_arr *array,
+ struct vmci_handle entry_handle);
+struct vmci_handle *vmci_handle_arr_get_handles(struct vmci_handle_arr *array);
+
+#endif /* _VMCI_HANDLE_ARRAY_H_ */