From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001 From: AndrĂ© Fabian Silva Delgado Date: Wed, 5 Aug 2015 17:04:01 -0300 Subject: Initial import --- arch/powerpc/sysdev/msi_bitmap.c | 267 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 267 insertions(+) create mode 100644 arch/powerpc/sysdev/msi_bitmap.c (limited to 'arch/powerpc/sysdev/msi_bitmap.c') diff --git a/arch/powerpc/sysdev/msi_bitmap.c b/arch/powerpc/sysdev/msi_bitmap.c new file mode 100644 index 000000000..73b64c735 --- /dev/null +++ b/arch/powerpc/sysdev/msi_bitmap.c @@ -0,0 +1,267 @@ +/* + * 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 +#include +#include +#include +#include + +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: ( )+ */ + 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 = ∝ + + /* 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 */ -- cgit v1.2.3-54-g00ecf