add missing file

hermit/mm/hbmemory.c

@@ -0,0 +1,170 @@
+/*
+ * Copyright (c) 2016, Stefan Lankes, RWTH Aachen University
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *    * Redistributions of source code must retain the above copyright
+ *      notice, this list of conditions and the following disclaimer.
+ *    * Redistributions in binary form must reproduce the above copyright
+ *      notice, this list of conditions and the following disclaimer in the
+ *      documentation and/or other materials provided with the distribution.
+ *    * Neither the name of the University nor the names of its contributors
+ *      may be used to endorse or promote products derived from this
+ *      software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <hermit/stddef.h>
+#include <hermit/stdlib.h>
+#include <hermit/stdio.h>
+#include <hermit/string.h>
+#include <hermit/spinlock.h>
+#include <hermit/memory.h>
+
+#include <asm/atomic.h>
+#include <asm/page.h>
+
+typedef struct free_list {
+	size_t start, end;
+	struct free_list* next;
+	struct free_list* prev;
+} free_list_t;
+
+extern size_t hbmem_base;
+extern size_t hbmem_size;
+
+static spinlock_t list_lock = SPINLOCK_INIT;
+
+static free_list_t init_list = {0, 0, NULL, NULL};
+static free_list_t* free_start = &init_list;
+
+extern atomic_int64_t total_pages;
+extern atomic_int64_t total_allocated_pages;
+extern atomic_int64_t total_available_pages;
+
+size_t hbmem_get_pages(size_t npages)
+{
+	size_t i, ret = 0;
+	free_list_t* curr = free_start;
+
+	if (BUILTIN_EXPECT(!npages, 0))
+		return 0;
+	if (BUILTIN_EXPECT(npages > atomic_int64_read(&total_available_pages), 0))
+		return 0;
+
+	spinlock_lock(&list_lock);
+
+	while(curr) {
+		i = (curr->end - curr->start) / PAGE_SIZE;
+		if (i > npages) {
+			ret = curr->start;
+			curr->start += npages * PAGE_SIZE;
+			goto out;
+		} else if (i == npages) {
+			ret = curr->start;
+			if (curr->prev)
+				curr->prev = curr->next;
+			else
+				free_start = curr->next;
+			if (curr != &init_list)
+				kfree(curr);
+			goto out;
+		}
+
+		curr = curr->next;
+	}
+out:
+	//kprintf("get_pages: ret 0%llx, curr->start 0x%llx, curr->end 0x%llx\n", ret, curr->start, curr->end);
+
+	spinlock_unlock(&list_lock);
+
+	if (ret) {
+		atomic_int64_add(&total_allocated_pages, npages);
+		atomic_int64_sub(&total_available_pages, npages);
+	}
+
+	return ret;
+}
+
+/* TODO: reunion of elements is still missing */
+int hbmem_put_pages(size_t phyaddr, size_t npages)
+{
+	free_list_t* curr = free_start;
+
+	if (BUILTIN_EXPECT(!phyaddr, 0))
+		return -EINVAL;
+	if (BUILTIN_EXPECT(!npages, 0))
+		return -EINVAL;
+
+	spinlock_lock(&list_lock);
+
+	while(curr) {
+		if (phyaddr+npages*PAGE_SIZE == curr->start) {
+			curr->start = phyaddr;
+			goto out;
+		} else if (phyaddr == curr->end) {
+			curr->end += npages*PAGE_SIZE;
+			goto out;
+		} if (phyaddr > curr->end) {
+			free_list_t* n = kmalloc(sizeof(free_list_t));
+
+			if (BUILTIN_EXPECT(!n, 0))
+				goto out_err;
+
+			/* add new element */
+			n->start = phyaddr;
+			n->end = phyaddr + npages * PAGE_SIZE;
+			n->prev = curr;
+			n->next = curr->next;
+			curr->next = n;
+		}
+
+		curr = curr->next;
+	}
+out:
+	spinlock_unlock(&list_lock);
+
+	atomic_int64_sub(&total_allocated_pages, npages);
+	atomic_int64_add(&total_available_pages, npages);
+
+	return 0;
+
+out_err:
+	spinlock_unlock(&list_lock);
+
+	return -ENOMEM;
+}
+
+int is_hbmem_available(void)
+{
+	return (hbmem_base != 0);
+}
+
+int hbmemory_init(void)
+{
+	if (!hbmem_base)
+		return 0;
+
+	// determine available memory
+	atomic_int64_add(&total_pages, hbmem_size >> PAGE_BITS);
+	atomic_int64_add(&total_available_pages, hbmem_size >> PAGE_BITS);
+
+	//initialize free list
+	init_list.start = hbmem_base;
+	init_list.end = hbmem_base + hbmem_size;
+
+	kprintf("free list for hbmem starts at 0x%zx, limit 0x%zx\n", init_list.start, init_list.end);
+
+	return 0;
+}