--- /dev/null
+/*
+ * Copyright 2006-2008, Michael Ellerman, IBM Corporation.
+ *
+ * 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 of the
+ * License.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/bitmap.h>
+#include <asm/msi_bitmap.h>
+
+int msi_bitmap_alloc_hwirqs(struct msi_bitmap *bmp, int num)
+{
+ unsigned long flags;
+ int offset, order = get_count_order(num);
+
+ spin_lock_irqsave(&bmp->lock, flags);
+ /*
+ * This is fast, but stricter than we need. We might want to add
+ * a fallback routine which does a linear search with no alignment.
+ */
+ offset = bitmap_find_free_region(bmp->bitmap, bmp->irq_count, order);
+ spin_unlock_irqrestore(&bmp->lock, flags);
+
+ pr_debug("msi_bitmap: allocated 0x%x (2^%d) at offset 0x%x\n",
+ num, order, offset);
+
+ return offset;
+}
+
+void msi_bitmap_free_hwirqs(struct msi_bitmap *bmp, unsigned int offset,
+ unsigned int num)
+{
+ unsigned long flags;
+ int order = get_count_order(num);
+
+ pr_debug("msi_bitmap: freeing 0x%x (2^%d) at offset 0x%x\n",
+ num, order, offset);
+
+ spin_lock_irqsave(&bmp->lock, flags);
+ bitmap_release_region(bmp->bitmap, offset, order);
+ spin_unlock_irqrestore(&bmp->lock, flags);
+}
+
+void msi_bitmap_reserve_hwirq(struct msi_bitmap *bmp, unsigned int hwirq)
+{
+ unsigned long flags;
+
+ pr_debug("msi_bitmap: reserving hwirq 0x%x\n", hwirq);
+
+ spin_lock_irqsave(&bmp->lock, flags);
+ bitmap_allocate_region(bmp->bitmap, hwirq, 0);
+ spin_unlock_irqrestore(&bmp->lock, flags);
+}
+
+/**
+ * msi_bitmap_reserve_dt_hwirqs - Reserve irqs specified in the device tree.
+ * @bmp: pointer to the MSI bitmap.
+ *
+ * Looks in the device tree to see if there is a property specifying which
+ * irqs can be used for MSI. If found those irqs reserved in the device tree
+ * are reserved in the bitmap.
+ *
+ * Returns 0 for success, < 0 if there was an error, and > 0 if no property
+ * was found in the device tree.
+ **/
+int msi_bitmap_reserve_dt_hwirqs(struct msi_bitmap *bmp)
+{
+ int i, j, len;
+ const u32 *p;
+
+ if (!bmp->of_node)
+ return 1;
+
+ p = of_get_property(bmp->of_node, "msi-available-ranges", &len);
+ if (!p) {
+ pr_debug("msi_bitmap: no msi-available-ranges property " \
+ "found on %s\n", bmp->of_node->full_name);
+ return 1;
+ }
+
+ if (len % (2 * sizeof(u32)) != 0) {
+ printk(KERN_WARNING "msi_bitmap: Malformed msi-available-ranges"
+ " property on %s\n", bmp->of_node->full_name);
+ return -EINVAL;
+ }
+
+ bitmap_allocate_region(bmp->bitmap, 0, get_count_order(bmp->irq_count));
+
+ spin_lock(&bmp->lock);
+
+ /* Format is: (<u32 start> <u32 count>)+ */
+ len /= 2 * sizeof(u32);
+ for (i = 0; i < len; i++, p += 2) {
+ for (j = 0; j < *(p + 1); j++)
+ bitmap_release_region(bmp->bitmap, *p + j, 0);
+ }
+
+ spin_unlock(&bmp->lock);
+
+ return 0;
+}
+
+int msi_bitmap_alloc(struct msi_bitmap *bmp, unsigned int irq_count,
+ struct device_node *of_node)
+{
+ int size;
+
+ if (!irq_count)
+ return -EINVAL;
+
+ size = BITS_TO_LONGS(irq_count) * sizeof(long);
+ pr_debug("msi_bitmap: allocator bitmap size is 0x%x bytes\n", size);
+
+ bmp->bitmap = zalloc_maybe_bootmem(size, GFP_KERNEL);
+ if (!bmp->bitmap) {
+ pr_debug("msi_bitmap: ENOMEM allocating allocator bitmap!\n");
+ return -ENOMEM;
+ }
+
+ /* We zalloc'ed the bitmap, so all irqs are free by default */
+ spin_lock_init(&bmp->lock);
+ bmp->of_node = of_node_get(of_node);
+ bmp->irq_count = irq_count;
+
+ return 0;
+}
+
+void msi_bitmap_free(struct msi_bitmap *bmp)
+{
+ /* we can't free the bitmap we don't know if it's bootmem etc. */
+ of_node_put(bmp->of_node);
+ bmp->bitmap = NULL;
+}
+
+#ifdef CONFIG_MSI_BITMAP_SELFTEST
+
+#define check(x) \
+ if (!(x)) printk("msi_bitmap: test failed at line %d\n", __LINE__);
+
+void test_basics(void)
+{
+ struct msi_bitmap bmp;
+ int i, size = 512;
+
+ /* Can't allocate a bitmap of 0 irqs */
+ check(msi_bitmap_alloc(&bmp, 0, NULL) != 0);
+
+ /* of_node may be NULL */
+ check(0 == msi_bitmap_alloc(&bmp, size, NULL));
+
+ /* Should all be free by default */
+ check(0 == bitmap_find_free_region(bmp.bitmap, size,
+ get_count_order(size)));
+ bitmap_release_region(bmp.bitmap, 0, get_count_order(size));
+
+ /* With no node, there's no msi-available-ranges, so expect > 0 */
+ check(msi_bitmap_reserve_dt_hwirqs(&bmp) > 0);
+
+ /* Should all still be free */
+ check(0 == bitmap_find_free_region(bmp.bitmap, size,
+ get_count_order(size)));
+ bitmap_release_region(bmp.bitmap, 0, get_count_order(size));
+
+ /* Check we can fill it up and then no more */
+ for (i = 0; i < size; i++)
+ check(msi_bitmap_alloc_hwirqs(&bmp, 1) >= 0);
+
+ check(msi_bitmap_alloc_hwirqs(&bmp, 1) < 0);
+
+ /* Should all be allocated */
+ check(bitmap_find_free_region(bmp.bitmap, size, 0) < 0);
+
+ /* And if we free one we can then allocate another */
+ msi_bitmap_free_hwirqs(&bmp, size / 2, 1);
+ check(msi_bitmap_alloc_hwirqs(&bmp, 1) == size / 2);
+
+ msi_bitmap_free(&bmp);
+
+ /* Clients may check bitmap == NULL for "not-allocated" */
+ check(bmp.bitmap == NULL);
+
+ kfree(bmp.bitmap);
+}
+
+void test_of_node(void)
+{
+ u32 prop_data[] = { 10, 10, 25, 3, 40, 1, 100, 100, 200, 20 };
+ const char *expected_str = "0-9,20-24,28-39,41-99,220-255";
+ char *prop_name = "msi-available-ranges";
+ char *node_name = "/fakenode";
+ struct device_node of_node;
+ struct property prop;
+ struct msi_bitmap bmp;
+ int size = 256;
+ DECLARE_BITMAP(expected, size);
+
+ /* There should really be a struct device_node allocator */
+ memset(&of_node, 0, sizeof(of_node));
+ kref_init(&of_node.kref);
+ of_node.full_name = node_name;
+
+ check(0 == msi_bitmap_alloc(&bmp, size, &of_node));
+
+ /* No msi-available-ranges, so expect > 0 */
+ check(msi_bitmap_reserve_dt_hwirqs(&bmp) > 0);
+
+ /* Should all still be free */
+ check(0 == bitmap_find_free_region(bmp.bitmap, size,
+ get_count_order(size)));
+ bitmap_release_region(bmp.bitmap, 0, get_count_order(size));
+
+ /* Now create a fake msi-available-ranges property */
+
+ /* There should really .. oh whatever */
+ memset(&prop, 0, sizeof(prop));
+ prop.name = prop_name;
+ prop.value = &prop_data;
+ prop.length = sizeof(prop_data);
+
+ of_node.properties = ∝
+
+ /* msi-available-ranges, so expect == 0 */
+ check(msi_bitmap_reserve_dt_hwirqs(&bmp) == 0);
+
+ /* Check we got the expected result */
+ check(0 == bitmap_parselist(expected_str, expected, size));
+ check(bitmap_equal(expected, bmp.bitmap, size));
+
+ msi_bitmap_free(&bmp);
+ kfree(bmp.bitmap);
+}
+
+int msi_bitmap_selftest(void)
+{
+ printk(KERN_DEBUG "Running MSI bitmap self-tests ...\n");
+
+ test_basics();
+ test_of_node();
+
+ return 0;
+}
+late_initcall(msi_bitmap_selftest);
+#endif /* CONFIG_MSI_BITMAP_SELFTEST */
projects / linux-2.6-omap-h63xx.git / commitdiff