276 lines
7.3 KiB
C
276 lines
7.3 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Copyright 2006-2008, Michael Ellerman, IBM Corporation.
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*/
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#include <linux/slab.h>
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#include <linux/kernel.h>
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#include <linux/kmemleak.h>
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#include <linux/bitmap.h>
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#include <linux/memblock.h>
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#include <asm/msi_bitmap.h>
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#include <asm/setup.h>
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int msi_bitmap_alloc_hwirqs(struct msi_bitmap *bmp, int num)
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{
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unsigned long flags;
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int offset, order = get_count_order(num);
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spin_lock_irqsave(&bmp->lock, flags);
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offset = bitmap_find_next_zero_area(bmp->bitmap, bmp->irq_count, 0,
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num, (1 << order) - 1);
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if (offset > bmp->irq_count)
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goto err;
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bitmap_set(bmp->bitmap, offset, num);
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spin_unlock_irqrestore(&bmp->lock, flags);
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pr_debug("msi_bitmap: allocated 0x%x at offset 0x%x\n", num, offset);
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return offset;
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err:
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spin_unlock_irqrestore(&bmp->lock, flags);
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return -ENOMEM;
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}
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EXPORT_SYMBOL(msi_bitmap_alloc_hwirqs);
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void msi_bitmap_free_hwirqs(struct msi_bitmap *bmp, unsigned int offset,
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unsigned int num)
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{
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unsigned long flags;
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pr_debug("msi_bitmap: freeing 0x%x at offset 0x%x\n",
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num, offset);
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spin_lock_irqsave(&bmp->lock, flags);
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bitmap_clear(bmp->bitmap, offset, num);
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spin_unlock_irqrestore(&bmp->lock, flags);
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}
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EXPORT_SYMBOL(msi_bitmap_free_hwirqs);
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void msi_bitmap_reserve_hwirq(struct msi_bitmap *bmp, unsigned int hwirq)
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{
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unsigned long flags;
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pr_debug("msi_bitmap: reserving hwirq 0x%x\n", hwirq);
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spin_lock_irqsave(&bmp->lock, flags);
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bitmap_allocate_region(bmp->bitmap, hwirq, 0);
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spin_unlock_irqrestore(&bmp->lock, flags);
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}
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/**
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* msi_bitmap_reserve_dt_hwirqs - Reserve irqs specified in the device tree.
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* @bmp: pointer to the MSI bitmap.
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*
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* Looks in the device tree to see if there is a property specifying which
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* irqs can be used for MSI. If found those irqs reserved in the device tree
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* are reserved in the bitmap.
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*
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* Returns 0 for success, < 0 if there was an error, and > 0 if no property
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* was found in the device tree.
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**/
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int msi_bitmap_reserve_dt_hwirqs(struct msi_bitmap *bmp)
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{
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int i, j, len;
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const u32 *p;
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if (!bmp->of_node)
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return 1;
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p = of_get_property(bmp->of_node, "msi-available-ranges", &len);
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if (!p) {
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pr_debug("msi_bitmap: no msi-available-ranges property " \
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"found on %pOF\n", bmp->of_node);
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return 1;
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}
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if (len % (2 * sizeof(u32)) != 0) {
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printk(KERN_WARNING "msi_bitmap: Malformed msi-available-ranges"
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" property on %pOF\n", bmp->of_node);
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return -EINVAL;
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}
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bitmap_allocate_region(bmp->bitmap, 0, get_count_order(bmp->irq_count));
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spin_lock(&bmp->lock);
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/* Format is: (<u32 start> <u32 count>)+ */
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len /= 2 * sizeof(u32);
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for (i = 0; i < len; i++, p += 2) {
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for (j = 0; j < *(p + 1); j++)
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bitmap_release_region(bmp->bitmap, *p + j, 0);
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}
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spin_unlock(&bmp->lock);
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return 0;
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}
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int __ref msi_bitmap_alloc(struct msi_bitmap *bmp, unsigned int irq_count,
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struct device_node *of_node)
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{
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int size;
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if (!irq_count)
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return -EINVAL;
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size = BITS_TO_LONGS(irq_count) * sizeof(long);
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pr_debug("msi_bitmap: allocator bitmap size is 0x%x bytes\n", size);
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bmp->bitmap_from_slab = slab_is_available();
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if (bmp->bitmap_from_slab)
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bmp->bitmap = kzalloc(size, GFP_KERNEL);
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else {
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bmp->bitmap = memblock_alloc(size, SMP_CACHE_BYTES);
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if (!bmp->bitmap)
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panic("%s: Failed to allocate %u bytes\n", __func__,
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size);
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/* the bitmap won't be freed from memblock allocator */
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kmemleak_not_leak(bmp->bitmap);
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}
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if (!bmp->bitmap) {
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pr_debug("msi_bitmap: ENOMEM allocating allocator bitmap!\n");
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return -ENOMEM;
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}
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/* We zalloc'ed the bitmap, so all irqs are free by default */
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spin_lock_init(&bmp->lock);
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bmp->of_node = of_node_get(of_node);
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bmp->irq_count = irq_count;
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return 0;
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}
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void msi_bitmap_free(struct msi_bitmap *bmp)
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{
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if (bmp->bitmap_from_slab)
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kfree(bmp->bitmap);
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of_node_put(bmp->of_node);
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bmp->bitmap = NULL;
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}
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#ifdef CONFIG_MSI_BITMAP_SELFTEST
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static void __init test_basics(void)
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{
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struct msi_bitmap bmp;
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int rc, i, size = 512;
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/* Can't allocate a bitmap of 0 irqs */
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WARN_ON(msi_bitmap_alloc(&bmp, 0, NULL) == 0);
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/* of_node may be NULL */
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WARN_ON(msi_bitmap_alloc(&bmp, size, NULL));
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/* Should all be free by default */
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WARN_ON(bitmap_find_free_region(bmp.bitmap, size, get_count_order(size)));
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bitmap_release_region(bmp.bitmap, 0, get_count_order(size));
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/* With no node, there's no msi-available-ranges, so expect > 0 */
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WARN_ON(msi_bitmap_reserve_dt_hwirqs(&bmp) <= 0);
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/* Should all still be free */
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WARN_ON(bitmap_find_free_region(bmp.bitmap, size, get_count_order(size)));
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bitmap_release_region(bmp.bitmap, 0, get_count_order(size));
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/* Check we can fill it up and then no more */
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for (i = 0; i < size; i++)
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WARN_ON(msi_bitmap_alloc_hwirqs(&bmp, 1) < 0);
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WARN_ON(msi_bitmap_alloc_hwirqs(&bmp, 1) >= 0);
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/* Should all be allocated */
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WARN_ON(bitmap_find_free_region(bmp.bitmap, size, 0) >= 0);
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/* And if we free one we can then allocate another */
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msi_bitmap_free_hwirqs(&bmp, size / 2, 1);
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WARN_ON(msi_bitmap_alloc_hwirqs(&bmp, 1) != size / 2);
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/* Free most of them for the alignment tests */
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msi_bitmap_free_hwirqs(&bmp, 3, size - 3);
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/* Check we get a naturally aligned offset */
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rc = msi_bitmap_alloc_hwirqs(&bmp, 2);
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WARN_ON(rc < 0 && rc % 2 != 0);
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rc = msi_bitmap_alloc_hwirqs(&bmp, 4);
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WARN_ON(rc < 0 && rc % 4 != 0);
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rc = msi_bitmap_alloc_hwirqs(&bmp, 8);
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WARN_ON(rc < 0 && rc % 8 != 0);
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rc = msi_bitmap_alloc_hwirqs(&bmp, 9);
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WARN_ON(rc < 0 && rc % 16 != 0);
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rc = msi_bitmap_alloc_hwirqs(&bmp, 3);
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WARN_ON(rc < 0 && rc % 4 != 0);
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rc = msi_bitmap_alloc_hwirqs(&bmp, 7);
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WARN_ON(rc < 0 && rc % 8 != 0);
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rc = msi_bitmap_alloc_hwirqs(&bmp, 121);
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WARN_ON(rc < 0 && rc % 128 != 0);
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msi_bitmap_free(&bmp);
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/* Clients may WARN_ON bitmap == NULL for "not-allocated" */
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WARN_ON(bmp.bitmap != NULL);
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}
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static void __init test_of_node(void)
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{
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u32 prop_data[] = { 10, 10, 25, 3, 40, 1, 100, 100, 200, 20 };
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const char *expected_str = "0-9,20-24,28-39,41-99,220-255";
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char *prop_name = "msi-available-ranges";
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char *node_name = "/fakenode";
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struct device_node of_node;
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struct property prop;
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struct msi_bitmap bmp;
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#define SIZE_EXPECTED 256
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DECLARE_BITMAP(expected, SIZE_EXPECTED);
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/* There should really be a struct device_node allocator */
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memset(&of_node, 0, sizeof(of_node));
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of_node_init(&of_node);
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of_node.full_name = node_name;
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WARN_ON(msi_bitmap_alloc(&bmp, SIZE_EXPECTED, &of_node));
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/* No msi-available-ranges, so expect > 0 */
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WARN_ON(msi_bitmap_reserve_dt_hwirqs(&bmp) <= 0);
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/* Should all still be free */
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WARN_ON(bitmap_find_free_region(bmp.bitmap, SIZE_EXPECTED,
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get_count_order(SIZE_EXPECTED)));
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bitmap_release_region(bmp.bitmap, 0, get_count_order(SIZE_EXPECTED));
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/* Now create a fake msi-available-ranges property */
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/* There should really .. oh whatever */
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memset(&prop, 0, sizeof(prop));
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prop.name = prop_name;
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prop.value = &prop_data;
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prop.length = sizeof(prop_data);
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of_node.properties = ∝
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/* msi-available-ranges, so expect == 0 */
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WARN_ON(msi_bitmap_reserve_dt_hwirqs(&bmp));
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/* Check we got the expected result */
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WARN_ON(bitmap_parselist(expected_str, expected, SIZE_EXPECTED));
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WARN_ON(!bitmap_equal(expected, bmp.bitmap, SIZE_EXPECTED));
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msi_bitmap_free(&bmp);
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kfree(bmp.bitmap);
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}
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static int __init msi_bitmap_selftest(void)
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{
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printk(KERN_DEBUG "Running MSI bitmap self-tests ...\n");
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test_basics();
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test_of_node();
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return 0;
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}
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late_initcall(msi_bitmap_selftest);
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#endif /* CONFIG_MSI_BITMAP_SELFTEST */
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