![Li Zhong](/assets/img/avatar_default.png)
This patch uses of_node_init() to initialize the kobject in the fake node used in test_of_node(), to avoid following kobject warning. [ 0.897654] kobject: '(null)' (c0000007ca183a08): is not initialized, yet kobject_put() is being called. [ 0.897682] ------------[ cut here ]------------ [ 0.897688] WARNING: at lib/kobject.c:670 [ 0.897692] Modules linked in: [ 0.897701] CPU: 4 PID: 1 Comm: swapper/0 Not tainted 3.14.0+ #1 [ 0.897708] task: c0000007ca100000 ti: c0000007ca180000 task.ti: c0000007ca180000 [ 0.897715] NIP: c00000000046a1f0 LR: c00000000046a1ec CTR: 0000000001704660 [ 0.897721] REGS: c0000007ca1835c0 TRAP: 0700 Not tainted (3.14.0+) [ 0.897727] MSR: 8000000000029032 <SF,EE,ME,IR,DR,RI> CR: 28000024 XER: 0000000d [ 0.897749] CFAR: c0000000008ef4ec SOFTE: 1 GPR00: c00000000046a1ec c0000007ca183840 c0000000014c59b8 000000000000005c GPR04: 0000000000000001 c000000000129770 0000000000000000 0000000000000001 GPR08: 0000000000000000 0000000000000000 0000000000000000 0000000000003fef GPR12: 0000000000000000 c00000000f221200 c00000000000c350 0000000000000000 GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 GPR20: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 GPR24: 0000000000000000 c00000000144e808 c000000000c56f20 00000000000000d8 GPR28: c000000000cd5058 0000000000000000 c000000001454ca8 c0000007ca183a08 [ 0.897856] NIP [c00000000046a1f0] .kobject_put+0xa0/0xb0 [ 0.897863] LR [c00000000046a1ec] .kobject_put+0x9c/0xb0 [ 0.897868] Call Trace: [ 0.897874] [c0000007ca183840] [c00000000046a1ec] .kobject_put+0x9c/0xb0 (unreliable) [ 0.897885] [c0000007ca1838c0] [c000000000743f9c] .of_node_put+0x2c/0x50 [ 0.897894] [c0000007ca183940] [c000000000c83954] .test_of_node+0x1dc/0x208 [ 0.897902] [c0000007ca183b80] [c000000000c839a4] .msi_bitmap_selftest+0x24/0x38 [ 0.897913] [c0000007ca183bf0] [c00000000000bb34] .do_one_initcall+0x144/0x200 [ 0.897922] [c0000007ca183ce0] [c000000000c748e4] .kernel_init_freeable+0x2b4/0x394 [ 0.897931] [c0000007ca183db0] [c00000000000c374] .kernel_init+0x24/0x130 [ 0.897940] [c0000007ca183e30] [c00000000000a2f4] .ret_from_kernel_thread+0x5c/0x68 [ 0.897947] Instruction dump: [ 0.897952] 7fe3fb78 38210080 e8010010 ebe1fff8 7c0803a6 4800014c e89f0000 3c62ff6e [ 0.897971] 7fe5fb78 3863a950 48485279 60000000 <0fe00000> 39000000 393f0038 4bffff80 [ 0.897992] ---[ end trace 1eeffdb9f825a556 ]--- Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
250 lines
6.5 KiB
C
250 lines
6.5 KiB
C
/*
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* Copyright 2006-2008, Michael Ellerman, IBM Corporation.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; version 2 of the
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* License.
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*
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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/bitmap.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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/*
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* This is fast, but stricter than we need. We might want to add
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* a fallback routine which does a linear search with no alignment.
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*/
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offset = bitmap_find_free_region(bmp->bitmap, bmp->irq_count, order);
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spin_unlock_irqrestore(&bmp->lock, flags);
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pr_debug("msi_bitmap: allocated 0x%x (2^%d) at offset 0x%x\n",
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num, order, offset);
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return offset;
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}
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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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int order = get_count_order(num);
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pr_debug("msi_bitmap: freeing 0x%x (2^%d) at offset 0x%x\n",
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num, order, offset);
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spin_lock_irqsave(&bmp->lock, flags);
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bitmap_release_region(bmp->bitmap, offset, order);
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spin_unlock_irqrestore(&bmp->lock, flags);
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}
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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 %s\n", bmp->of_node->full_name);
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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 %s\n", bmp->of_node->full_name);
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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 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 = zalloc_maybe_bootmem(size, GFP_KERNEL);
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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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/* we can't free the bitmap we don't know if it's bootmem etc. */
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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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#define check(x) \
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if (!(x)) printk("msi_bitmap: test failed at line %d\n", __LINE__);
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void __init test_basics(void)
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{
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struct msi_bitmap bmp;
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int i, size = 512;
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/* Can't allocate a bitmap of 0 irqs */
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check(msi_bitmap_alloc(&bmp, 0, NULL) != 0);
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/* of_node may be NULL */
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check(0 == msi_bitmap_alloc(&bmp, size, NULL));
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/* Should all be free by default */
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check(0 == bitmap_find_free_region(bmp.bitmap, size,
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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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check(msi_bitmap_reserve_dt_hwirqs(&bmp) > 0);
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/* Should all still be free */
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check(0 == bitmap_find_free_region(bmp.bitmap, size,
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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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check(msi_bitmap_alloc_hwirqs(&bmp, 1) >= 0);
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check(msi_bitmap_alloc_hwirqs(&bmp, 1) < 0);
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/* Should all be allocated */
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check(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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check(msi_bitmap_alloc_hwirqs(&bmp, 1) == size / 2);
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msi_bitmap_free(&bmp);
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/* Clients may check bitmap == NULL for "not-allocated" */
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check(bmp.bitmap == NULL);
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kfree(bmp.bitmap);
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}
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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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int size = 256;
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DECLARE_BITMAP(expected, size);
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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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check(0 == msi_bitmap_alloc(&bmp, size, &of_node));
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/* No msi-available-ranges, so expect > 0 */
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check(msi_bitmap_reserve_dt_hwirqs(&bmp) > 0);
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/* Should all still be free */
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check(0 == bitmap_find_free_region(bmp.bitmap, size,
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get_count_order(size)));
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bitmap_release_region(bmp.bitmap, 0, get_count_order(size));
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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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check(msi_bitmap_reserve_dt_hwirqs(&bmp) == 0);
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/* Check we got the expected result */
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check(0 == bitmap_parselist(expected_str, expected, size));
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check(bitmap_equal(expected, bmp.bitmap, size));
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msi_bitmap_free(&bmp);
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kfree(bmp.bitmap);
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}
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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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