A simple memory pool that is used the the mbuf support. Can be called

from within an interrupt handler, and wastes pretty much memory.
Knows only about two different block sizes, and implements them by
using a simple free list.


git-svn-id: file:///srv/svn/repos/haiku/trunk/current@7398 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/add-ons/kernel/drivers/network/ipro1000/mempool.c

@@ -0,0 +1,143 @@
+/* Intel PRO/1000 Family Driver
+ * Copyright (C) 2004 Marcus Overhagen <[email protected]>. All rights reserved.
+ */
+#include <KernelExport.h>
+#include <malloc.h>
+#include "mempool.h"
+#include "if_compat.h"
+#include "debug.h"
+
+spinlock pool_lock = 0;
+
+void *mbuf_pool = 0;
+void *chunk_pool = 0;
+
+void *mbuf_head = 0;
+void *chunk_head = 0;
+
+void *
+area_malloc(int size)
+{
+	void *p;
+	size = (size + B_PAGE_SIZE - 1) & ~(B_PAGE_SIZE - 1);
+	
+	if (create_area("area_malloc", &p, B_ANY_KERNEL_ADDRESS, size, B_FULL_LOCK,0) < 0)
+		return 0;
+	return p;
+}
+
+void
+area_free(void *p)
+{
+	delete_area(area_for(p));
+}
+
+int
+mempool_init(int count)
+{
+	int chunk_size = 2048;
+	int mbuf_size = (sizeof(struct mbuf) + 15) & ~15;
+
+	int chunk_alloc_size = chunk_size * (count + 1);
+	int mbuf_alloc_size = mbuf_size * (count + 1);
+	
+	char *chunk_base;
+	char *mbuf_base;
+	
+	int i;
+	
+	TRACE("chunk_size %d, mbuf_size %d\n", chunk_size, mbuf_size);
+	TRACE("chunk_alloc_size %d, mbuf_alloc_size %d\n", chunk_alloc_size, mbuf_alloc_size);
+	
+	chunk_pool = area_malloc(chunk_alloc_size);
+	if (!chunk_pool) {
+		TRACE("failed to allocate chunk storage of %d bytes\n", chunk_alloc_size);
+		return -1;
+	}
+	mbuf_pool = area_malloc(mbuf_alloc_size);
+	if (!mbuf_pool) {
+		TRACE("failed to allocate mbuf storage of %d bytes\n", mbuf_alloc_size);
+		area_free(chunk_pool);
+		return -1;
+	}
+
+	chunk_base = (char *)(((unsigned long)chunk_pool + 2047) & ~2047);
+	mbuf_base  = (char *)(((unsigned long)mbuf_pool + 15) & ~15);
+	
+	for (i = 0; i < count; i++) {
+		chunk_pool_put(chunk_base + i * chunk_size);
+		mbuf_pool_put(mbuf_base + i * mbuf_size);
+	}
+
+	TRACE("mempool init success\n");
+	return 0;
+}
+
+void
+mempool_exit()
+{
+	area_free(chunk_pool);
+	area_free(mbuf_pool);
+}
+
+void *
+mbuf_pool_get()
+{
+	void *p;
+	cpu_status s;
+	s = disable_interrupts();
+	acquire_spinlock(&pool_lock);
+	
+	p = mbuf_head;
+	if (p)
+		mbuf_head = *(void **)p;
+
+	release_spinlock(&pool_lock);
+	restore_interrupts(s);
+	return p;
+}
+
+void
+mbuf_pool_put(void *p)
+{
+	cpu_status s;
+	s = disable_interrupts();
+	acquire_spinlock(&pool_lock);
+
+	*(void **)p = mbuf_head;
+	mbuf_head = p;
+
+	release_spinlock(&pool_lock);
+	restore_interrupts(s);
+}
+
+void *
+chunk_pool_get()
+{
+	void *p;
+	cpu_status s;
+	s = disable_interrupts();
+	acquire_spinlock(&pool_lock);
+
+	p = chunk_head;
+	if (p)
+		chunk_head = *(void **)p;
+
+	release_spinlock(&pool_lock);
+	restore_interrupts(s);
+	return p;
+}
+
+void
+chunk_pool_put(void *p)
+{
+	cpu_status s;
+	s = disable_interrupts();
+	acquire_spinlock(&pool_lock);
+
+	*(void **)p = chunk_head;
+	chunk_head = p;
+
+	release_spinlock(&pool_lock);
+	restore_interrupts(s);
+}

src/add-ons/kernel/drivers/network/ipro1000/mempool.h

@@ -0,0 +1,16 @@
+/* Intel PRO/1000 Family Driver
+ * Copyright (C) 2004 Marcus Overhagen <[email protected]>. All rights reserved.
+ */
+#ifndef __MEMPOOL_H
+#define __MEMPOOL_H
+
+int mempool_init(int count);
+void mempool_exit();
+
+void *mbuf_pool_get();
+void *chunk_pool_get();
+
+void chunk_pool_put(void *p);
+void mbuf_pool_put(void *p);
+
+#endif