arch/powerpc/sysdev/msi_bitmap.c - kernel/msm - Git at Google

 /*
  * 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/slab.h>
 #include <linux/kernel.h>
 #include <linux/bitmap.h>
 #include <asm/msi_bitmap.h>
 #include <asm/setup.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);

 	offset = bitmap_find_next_zero_area(bmp->bitmap, bmp->irq_count, 0,
 					    num, (1 << order) - 1);
 	if (offset > bmp->irq_count)
 		goto err;

 	bitmap_set(bmp->bitmap, offset, num);
 	spin_unlock_irqrestore(&bmp->lock, flags);

 	pr_debug("msi_bitmap: allocated 0x%x at offset 0x%x\n", num, offset);

 	return offset;
 err:
 	spin_unlock_irqrestore(&bmp->lock, flags);
 	return -ENOMEM;
 }
 EXPORT_SYMBOL(msi_bitmap_alloc_hwirqs);

 void msi_bitmap_free_hwirqs(struct msi_bitmap *bmp, unsigned int offset,
 			    unsigned int num)
 {
 	unsigned long flags;

 	pr_debug("msi_bitmap: freeing 0x%x at offset 0x%x\n",
 		 num, offset);

 	spin_lock_irqsave(&bmp->lock, flags);
 	bitmap_clear(bmp->bitmap, offset, num);
 	spin_unlock_irqrestore(&bmp->lock, flags);
 }
 EXPORT_SYMBOL(msi_bitmap_free_hwirqs);

 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

 static void __init test_basics(void)
 {
 	struct msi_bitmap bmp;
 	int rc, i, size = 512;

 	/* Can't allocate a bitmap of 0 irqs */
 	WARN_ON(msi_bitmap_alloc(&bmp, 0, NULL) == 0);

 	/* of_node may be NULL */
 	WARN_ON(msi_bitmap_alloc(&bmp, size, NULL));

 	/* Should all be free by default */
 	WARN_ON(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 */
 	WARN_ON(msi_bitmap_reserve_dt_hwirqs(&bmp) <= 0);

 	/* Should all still be free */
 	WARN_ON(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++)
 		WARN_ON(msi_bitmap_alloc_hwirqs(&bmp, 1) < 0);

 	WARN_ON(msi_bitmap_alloc_hwirqs(&bmp, 1) >= 0);

 	/* Should all be allocated */
 	WARN_ON(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);
 	WARN_ON(msi_bitmap_alloc_hwirqs(&bmp, 1) != size / 2);

 	/* Free most of them for the alignment tests */
 	msi_bitmap_free_hwirqs(&bmp, 3, size - 3);

 	/* Check we get a naturally aligned offset */
 	rc = msi_bitmap_alloc_hwirqs(&bmp, 2);
 	WARN_ON(rc < 0 && rc % 2 != 0);
 	rc = msi_bitmap_alloc_hwirqs(&bmp, 4);
 	WARN_ON(rc < 0 && rc % 4 != 0);
 	rc = msi_bitmap_alloc_hwirqs(&bmp, 8);
 	WARN_ON(rc < 0 && rc % 8 != 0);
 	rc = msi_bitmap_alloc_hwirqs(&bmp, 9);
 	WARN_ON(rc < 0 && rc % 16 != 0);
 	rc = msi_bitmap_alloc_hwirqs(&bmp, 3);
 	WARN_ON(rc < 0 && rc % 4 != 0);
 	rc = msi_bitmap_alloc_hwirqs(&bmp, 7);
 	WARN_ON(rc < 0 && rc % 8 != 0);
 	rc = msi_bitmap_alloc_hwirqs(&bmp, 121);
 	WARN_ON(rc < 0 && rc % 128 != 0);

 	msi_bitmap_free(&bmp);

 	/* Clients may WARN_ON bitmap == NULL for "not-allocated" */
 	WARN_ON(bmp.bitmap != NULL);

 	kfree(bmp.bitmap);
 }

 static void __init 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));
 	of_node_init(&of_node);
 	of_node.full_name = node_name;

 	WARN_ON(msi_bitmap_alloc(&bmp, size, &of_node));

 	/* No msi-available-ranges, so expect > 0 */
 	WARN_ON(msi_bitmap_reserve_dt_hwirqs(&bmp) <= 0);

 	/* Should all still be free */
 	WARN_ON(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 = &prop;

 	/* msi-available-ranges, so expect == 0 */
 	WARN_ON(msi_bitmap_reserve_dt_hwirqs(&bmp));

 	/* Check we got the expected result */
 	WARN_ON(bitmap_parselist(expected_str, expected, size));
 	WARN_ON(!bitmap_equal(expected, bmp.bitmap, size));

 	msi_bitmap_free(&bmp);
 	kfree(bmp.bitmap);
 }

 static int __init 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 */
	/*
	* 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/slab.h>
	#include <linux/kernel.h>
	#include <linux/bitmap.h>
	#include <asm/msi_bitmap.h>
	#include <asm/setup.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);

	offset = bitmap_find_next_zero_area(bmp->bitmap, bmp->irq_count, 0,
	num, (1 << order) - 1);
	if (offset > bmp->irq_count)
	goto err;

	bitmap_set(bmp->bitmap, offset, num);
	spin_unlock_irqrestore(&bmp->lock, flags);

	pr_debug("msi_bitmap: allocated 0x%x at offset 0x%x\n", num, offset);

	return offset;
	err:
	spin_unlock_irqrestore(&bmp->lock, flags);
	return -ENOMEM;
	}
	EXPORT_SYMBOL(msi_bitmap_alloc_hwirqs);

	void msi_bitmap_free_hwirqs(struct msi_bitmap *bmp, unsigned int offset,
	unsigned int num)
	{
	unsigned long flags;

	pr_debug("msi_bitmap: freeing 0x%x at offset 0x%x\n",
	num, offset);

	spin_lock_irqsave(&bmp->lock, flags);
	bitmap_clear(bmp->bitmap, offset, num);
	spin_unlock_irqrestore(&bmp->lock, flags);
	}
	EXPORT_SYMBOL(msi_bitmap_free_hwirqs);

	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

	static void __init test_basics(void)
	{
	struct msi_bitmap bmp;
	int rc, i, size = 512;

	/* Can't allocate a bitmap of 0 irqs */
	WARN_ON(msi_bitmap_alloc(&bmp, 0, NULL) == 0);

	/* of_node may be NULL */
	WARN_ON(msi_bitmap_alloc(&bmp, size, NULL));

	/* Should all be free by default */
	WARN_ON(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 */
	WARN_ON(msi_bitmap_reserve_dt_hwirqs(&bmp) <= 0);

	/* Should all still be free */
	WARN_ON(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++)
	WARN_ON(msi_bitmap_alloc_hwirqs(&bmp, 1) < 0);

	WARN_ON(msi_bitmap_alloc_hwirqs(&bmp, 1) >= 0);

	/* Should all be allocated */
	WARN_ON(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);
	WARN_ON(msi_bitmap_alloc_hwirqs(&bmp, 1) != size / 2);

	/* Free most of them for the alignment tests */
	msi_bitmap_free_hwirqs(&bmp, 3, size - 3);

	/* Check we get a naturally aligned offset */
	rc = msi_bitmap_alloc_hwirqs(&bmp, 2);
	WARN_ON(rc < 0 && rc % 2 != 0);
	rc = msi_bitmap_alloc_hwirqs(&bmp, 4);
	WARN_ON(rc < 0 && rc % 4 != 0);
	rc = msi_bitmap_alloc_hwirqs(&bmp, 8);
	WARN_ON(rc < 0 && rc % 8 != 0);
	rc = msi_bitmap_alloc_hwirqs(&bmp, 9);
	WARN_ON(rc < 0 && rc % 16 != 0);
	rc = msi_bitmap_alloc_hwirqs(&bmp, 3);
	WARN_ON(rc < 0 && rc % 4 != 0);
	rc = msi_bitmap_alloc_hwirqs(&bmp, 7);
	WARN_ON(rc < 0 && rc % 8 != 0);
	rc = msi_bitmap_alloc_hwirqs(&bmp, 121);
	WARN_ON(rc < 0 && rc % 128 != 0);

	msi_bitmap_free(&bmp);

	/* Clients may WARN_ON bitmap == NULL for "not-allocated" */
	WARN_ON(bmp.bitmap != NULL);

	kfree(bmp.bitmap);
	}

	static void __init 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));
	of_node_init(&of_node);
	of_node.full_name = node_name;

	WARN_ON(msi_bitmap_alloc(&bmp, size, &of_node));

	/* No msi-available-ranges, so expect > 0 */
	WARN_ON(msi_bitmap_reserve_dt_hwirqs(&bmp) <= 0);

	/* Should all still be free */
	WARN_ON(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 = &prop;

	/* msi-available-ranges, so expect == 0 */
	WARN_ON(msi_bitmap_reserve_dt_hwirqs(&bmp));

	/* Check we got the expected result */
	WARN_ON(bitmap_parselist(expected_str, expected, size));
	WARN_ON(!bitmap_equal(expected, bmp.bitmap, size));

	msi_bitmap_free(&bmp);
	kfree(bmp.bitmap);
	}

	static int __init 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 */