metag: TCM support

Add some TCM support

Signed-off-by: James Hogan <james.hogan@imgtec.com>

1 files changed, 151 insertions, 0 deletions

diff --git a/arch/metag/kernel/tcm.c b/arch/metag/kernel/tcm.c
new file mode 100644
index 00000000000..5d102b31ce8
--- /dev/null
+++ b/arch/metag/kernel/tcm.c
@@ -0,0 +1,151 @@
+/*
+ * Copyright (C) 2010 Imagination Technologies Ltd.
+ */
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/spinlock.h>
+#include <linux/stddef.h>
+#include <linux/genalloc.h>
+#include <linux/string.h>
+#include <linux/list.h>
+#include <linux/slab.h>
+#include <asm/page.h>
+#include <asm/tcm.h>
+
+struct tcm_pool {
+	struct list_head list;
+	unsigned int tag;
+	unsigned long start;
+	unsigned long end;
+	struct gen_pool *pool;
+};
+
+static LIST_HEAD(pool_list);
+
+static struct tcm_pool *find_pool(unsigned int tag)
+{
+	struct list_head *lh;
+	struct tcm_pool *pool;
+
+	list_for_each(lh, &pool_list) {
+		pool = list_entry(lh, struct tcm_pool, list);
+		if (pool->tag == tag)
+			return pool;
+	}
+
+	return NULL;
+}
+
+/**
+ * tcm_alloc - allocate memory from a TCM pool
+ * @tag: tag of the pool to allocate memory from
+ * @len: number of bytes to be allocated
+ *
+ * Allocate the requested number of bytes from the pool matching
+ * the specified tag. Returns the address of the allocated memory
+ * or zero on failure.
+ */
+unsigned long tcm_alloc(unsigned int tag, size_t len)
+{
+	unsigned long vaddr;
+	struct tcm_pool *pool;
+
+	pool = find_pool(tag);
+	if (!pool)
+		return 0;
+
+	vaddr = gen_pool_alloc(pool->pool, len);
+	if (!vaddr)
+		return 0;
+
+	return vaddr;
+}
+
+/**
+ * tcm_free - free a block of memory to a TCM pool
+ * @tag: tag of the pool to free memory to
+ * @addr: address of the memory to be freed
+ * @len: number of bytes to be freed
+ *
+ * Free the requested number of bytes at a specific address to the
+ * pool matching the specified tag.
+ */
+void tcm_free(unsigned int tag, unsigned long addr, size_t len)
+{
+	struct tcm_pool *pool;
+
+	pool = find_pool(tag);
+	if (!pool)
+		return;
+	gen_pool_free(pool->pool, addr, len);
+}
+
+/**
+ * tcm_lookup_tag - find the tag matching an address
+ * @p: memory address to lookup the tag for
+ *
+ * Find the tag of the tcm memory region that contains the
+ * specified address. Returns %TCM_INVALID_TAG if no such
+ * memory region could be found.
+ */
+unsigned int tcm_lookup_tag(unsigned long p)
+{
+	struct list_head *lh;
+	struct tcm_pool *pool;
+	unsigned long addr = (unsigned long) p;
+
+	list_for_each(lh, &pool_list) {
+		pool = list_entry(lh, struct tcm_pool, list);
+		if (addr >= pool->start && addr < pool->end)
+			return pool->tag;
+	}
+
+	return TCM_INVALID_TAG;
+}
+
+/**
+ * tcm_add_region - add a memory region to TCM pool list
+ * @reg: descriptor of region to be added
+ *
+ * Add a region of memory to the TCM pool list. Returns 0 on success.
+ */
+int __init tcm_add_region(struct tcm_region *reg)
+{
+	struct tcm_pool *pool;
+
+	pool = kmalloc(sizeof(*pool), GFP_KERNEL);
+	if (!pool) {
+		pr_err("Failed to alloc memory for TCM pool!\n");
+		return -ENOMEM;
+	}
+
+	pool->tag = reg->tag;
+	pool->start = reg->res.start;
+	pool->end = reg->res.end;
+
+	/*
+	 * 2^3 = 8 bytes granularity to allow for 64bit access alignment.
+	 * -1 = NUMA node specifier.
+	 */
+	pool->pool = gen_pool_create(3, -1);
+
+	if (!pool->pool) {
+		pr_err("Failed to create TCM pool!\n");
+		kfree(pool);
+		return -ENOMEM;
+	}
+
+	if (gen_pool_add(pool->pool, reg->res.start,
+			 reg->res.end - reg->res.start + 1, -1)) {
+		pr_err("Failed to add memory to TCM pool!\n");
+		return -ENOMEM;
+	}
+	pr_info("Added %s TCM pool (%08x bytes @ %08x)\n",
+		reg->res.name, reg->res.end - reg->res.start + 1,
+		reg->res.start);
+
+	list_add_tail(&pool->list, &pool_list);
+
+	return 0;
+}