17e302869SMichael Ellerman /* 27e302869SMichael Ellerman * Copyright 2006-2008, Michael Ellerman, IBM Corporation. 37e302869SMichael Ellerman * 47e302869SMichael Ellerman * This program is free software; you can redistribute it and/or 57e302869SMichael Ellerman * modify it under the terms of the GNU General Public License 67e302869SMichael Ellerman * as published by the Free Software Foundation; version 2 of the 77e302869SMichael Ellerman * License. 87e302869SMichael Ellerman * 97e302869SMichael Ellerman */ 107e302869SMichael Ellerman 115a0e3ad6STejun Heo #include <linux/slab.h> 127e302869SMichael Ellerman #include <linux/kernel.h> 137e302869SMichael Ellerman #include <linux/bitmap.h> 147e302869SMichael Ellerman #include <asm/msi_bitmap.h> 15ae3a197eSDavid Howells #include <asm/setup.h> 167e302869SMichael Ellerman 177e302869SMichael Ellerman int msi_bitmap_alloc_hwirqs(struct msi_bitmap *bmp, int num) 187e302869SMichael Ellerman { 197e302869SMichael Ellerman unsigned long flags; 207e302869SMichael Ellerman int offset, order = get_count_order(num); 217e302869SMichael Ellerman 227e302869SMichael Ellerman spin_lock_irqsave(&bmp->lock, flags); 23b0345bbcSIan Munsie 24b0345bbcSIan Munsie offset = bitmap_find_next_zero_area(bmp->bitmap, bmp->irq_count, 0, 25b0345bbcSIan Munsie num, (1 << order) - 1); 26b0345bbcSIan Munsie if (offset > bmp->irq_count) 27b0345bbcSIan Munsie goto err; 28b0345bbcSIan Munsie 29b0345bbcSIan Munsie bitmap_set(bmp->bitmap, offset, num); 307e302869SMichael Ellerman spin_unlock_irqrestore(&bmp->lock, flags); 317e302869SMichael Ellerman 32b0345bbcSIan Munsie pr_debug("msi_bitmap: allocated 0x%x at offset 0x%x\n", num, offset); 337e302869SMichael Ellerman 347e302869SMichael Ellerman return offset; 35b0345bbcSIan Munsie err: 36b0345bbcSIan Munsie spin_unlock_irqrestore(&bmp->lock, flags); 37b0345bbcSIan Munsie return -ENOMEM; 387e302869SMichael Ellerman } 39b0345bbcSIan Munsie EXPORT_SYMBOL(msi_bitmap_alloc_hwirqs); 407e302869SMichael Ellerman 417e302869SMichael Ellerman void msi_bitmap_free_hwirqs(struct msi_bitmap *bmp, unsigned int offset, 427e302869SMichael Ellerman unsigned int num) 437e302869SMichael Ellerman { 447e302869SMichael Ellerman unsigned long flags; 457e302869SMichael Ellerman 46b0345bbcSIan Munsie pr_debug("msi_bitmap: freeing 0x%x at offset 0x%x\n", 47b0345bbcSIan Munsie num, offset); 487e302869SMichael Ellerman 497e302869SMichael Ellerman spin_lock_irqsave(&bmp->lock, flags); 50b0345bbcSIan Munsie bitmap_clear(bmp->bitmap, offset, num); 517e302869SMichael Ellerman spin_unlock_irqrestore(&bmp->lock, flags); 527e302869SMichael Ellerman } 53b0345bbcSIan Munsie EXPORT_SYMBOL(msi_bitmap_free_hwirqs); 547e302869SMichael Ellerman 557e302869SMichael Ellerman void msi_bitmap_reserve_hwirq(struct msi_bitmap *bmp, unsigned int hwirq) 567e302869SMichael Ellerman { 577e302869SMichael Ellerman unsigned long flags; 587e302869SMichael Ellerman 597e302869SMichael Ellerman pr_debug("msi_bitmap: reserving hwirq 0x%x\n", hwirq); 607e302869SMichael Ellerman 617e302869SMichael Ellerman spin_lock_irqsave(&bmp->lock, flags); 627e302869SMichael Ellerman bitmap_allocate_region(bmp->bitmap, hwirq, 0); 637e302869SMichael Ellerman spin_unlock_irqrestore(&bmp->lock, flags); 647e302869SMichael Ellerman } 657e302869SMichael Ellerman 667e302869SMichael Ellerman /** 677e302869SMichael Ellerman * msi_bitmap_reserve_dt_hwirqs - Reserve irqs specified in the device tree. 687e302869SMichael Ellerman * @bmp: pointer to the MSI bitmap. 697e302869SMichael Ellerman * 707e302869SMichael Ellerman * Looks in the device tree to see if there is a property specifying which 717e302869SMichael Ellerman * irqs can be used for MSI. If found those irqs reserved in the device tree 727e302869SMichael Ellerman * are reserved in the bitmap. 737e302869SMichael Ellerman * 747e302869SMichael Ellerman * Returns 0 for success, < 0 if there was an error, and > 0 if no property 757e302869SMichael Ellerman * was found in the device tree. 767e302869SMichael Ellerman **/ 777e302869SMichael Ellerman int msi_bitmap_reserve_dt_hwirqs(struct msi_bitmap *bmp) 787e302869SMichael Ellerman { 797e302869SMichael Ellerman int i, j, len; 807e302869SMichael Ellerman const u32 *p; 817e302869SMichael Ellerman 827e302869SMichael Ellerman if (!bmp->of_node) 837e302869SMichael Ellerman return 1; 847e302869SMichael Ellerman 857e302869SMichael Ellerman p = of_get_property(bmp->of_node, "msi-available-ranges", &len); 867e302869SMichael Ellerman if (!p) { 877e302869SMichael Ellerman pr_debug("msi_bitmap: no msi-available-ranges property " \ 887e302869SMichael Ellerman "found on %s\n", bmp->of_node->full_name); 897e302869SMichael Ellerman return 1; 907e302869SMichael Ellerman } 917e302869SMichael Ellerman 927e302869SMichael Ellerman if (len % (2 * sizeof(u32)) != 0) { 937e302869SMichael Ellerman printk(KERN_WARNING "msi_bitmap: Malformed msi-available-ranges" 947e302869SMichael Ellerman " property on %s\n", bmp->of_node->full_name); 957e302869SMichael Ellerman return -EINVAL; 967e302869SMichael Ellerman } 977e302869SMichael Ellerman 987e302869SMichael Ellerman bitmap_allocate_region(bmp->bitmap, 0, get_count_order(bmp->irq_count)); 997e302869SMichael Ellerman 1007e302869SMichael Ellerman spin_lock(&bmp->lock); 1017e302869SMichael Ellerman 1027e302869SMichael Ellerman /* Format is: (<u32 start> <u32 count>)+ */ 1037e302869SMichael Ellerman len /= 2 * sizeof(u32); 1047e302869SMichael Ellerman for (i = 0; i < len; i++, p += 2) { 1057e302869SMichael Ellerman for (j = 0; j < *(p + 1); j++) 1067e302869SMichael Ellerman bitmap_release_region(bmp->bitmap, *p + j, 0); 1077e302869SMichael Ellerman } 1087e302869SMichael Ellerman 1097e302869SMichael Ellerman spin_unlock(&bmp->lock); 1107e302869SMichael Ellerman 1117e302869SMichael Ellerman return 0; 1127e302869SMichael Ellerman } 1137e302869SMichael Ellerman 1147e302869SMichael Ellerman int msi_bitmap_alloc(struct msi_bitmap *bmp, unsigned int irq_count, 1157e302869SMichael Ellerman struct device_node *of_node) 1167e302869SMichael Ellerman { 1177e302869SMichael Ellerman int size; 1187e302869SMichael Ellerman 1197e302869SMichael Ellerman if (!irq_count) 1207e302869SMichael Ellerman return -EINVAL; 1217e302869SMichael Ellerman 1227e302869SMichael Ellerman size = BITS_TO_LONGS(irq_count) * sizeof(long); 1237e302869SMichael Ellerman pr_debug("msi_bitmap: allocator bitmap size is 0x%x bytes\n", size); 1247e302869SMichael Ellerman 1257e302869SMichael Ellerman bmp->bitmap = zalloc_maybe_bootmem(size, GFP_KERNEL); 1267e302869SMichael Ellerman if (!bmp->bitmap) { 1277e302869SMichael Ellerman pr_debug("msi_bitmap: ENOMEM allocating allocator bitmap!\n"); 1287e302869SMichael Ellerman return -ENOMEM; 1297e302869SMichael Ellerman } 1307e302869SMichael Ellerman 1317e302869SMichael Ellerman /* We zalloc'ed the bitmap, so all irqs are free by default */ 1327e302869SMichael Ellerman spin_lock_init(&bmp->lock); 1337e302869SMichael Ellerman bmp->of_node = of_node_get(of_node); 1347e302869SMichael Ellerman bmp->irq_count = irq_count; 1357e302869SMichael Ellerman 1367e302869SMichael Ellerman return 0; 1377e302869SMichael Ellerman } 1387e302869SMichael Ellerman 1397e302869SMichael Ellerman void msi_bitmap_free(struct msi_bitmap *bmp) 1407e302869SMichael Ellerman { 1417e302869SMichael Ellerman /* we can't free the bitmap we don't know if it's bootmem etc. */ 1427e302869SMichael Ellerman of_node_put(bmp->of_node); 1437e302869SMichael Ellerman bmp->bitmap = NULL; 1447e302869SMichael Ellerman } 1457e302869SMichael Ellerman 1467e302869SMichael Ellerman #ifdef CONFIG_MSI_BITMAP_SELFTEST 1477e302869SMichael Ellerman 1487e302869SMichael Ellerman #define check(x) \ 1497e302869SMichael Ellerman if (!(x)) printk("msi_bitmap: test failed at line %d\n", __LINE__); 1507e302869SMichael Ellerman 151e51df2c1SAnton Blanchard static void __init test_basics(void) 1527e302869SMichael Ellerman { 1537e302869SMichael Ellerman struct msi_bitmap bmp; 1547e302869SMichael Ellerman int i, size = 512; 1557e302869SMichael Ellerman 1567e302869SMichael Ellerman /* Can't allocate a bitmap of 0 irqs */ 1577e302869SMichael Ellerman check(msi_bitmap_alloc(&bmp, 0, NULL) != 0); 1587e302869SMichael Ellerman 1597e302869SMichael Ellerman /* of_node may be NULL */ 1607e302869SMichael Ellerman check(0 == msi_bitmap_alloc(&bmp, size, NULL)); 1617e302869SMichael Ellerman 1627e302869SMichael Ellerman /* Should all be free by default */ 1637e302869SMichael Ellerman check(0 == bitmap_find_free_region(bmp.bitmap, size, 1647e302869SMichael Ellerman get_count_order(size))); 1657e302869SMichael Ellerman bitmap_release_region(bmp.bitmap, 0, get_count_order(size)); 1667e302869SMichael Ellerman 1677e302869SMichael Ellerman /* With no node, there's no msi-available-ranges, so expect > 0 */ 1687e302869SMichael Ellerman check(msi_bitmap_reserve_dt_hwirqs(&bmp) > 0); 1697e302869SMichael Ellerman 1707e302869SMichael Ellerman /* Should all still be free */ 1717e302869SMichael Ellerman check(0 == bitmap_find_free_region(bmp.bitmap, size, 1727e302869SMichael Ellerman get_count_order(size))); 1737e302869SMichael Ellerman bitmap_release_region(bmp.bitmap, 0, get_count_order(size)); 1747e302869SMichael Ellerman 1757e302869SMichael Ellerman /* Check we can fill it up and then no more */ 1767e302869SMichael Ellerman for (i = 0; i < size; i++) 1777e302869SMichael Ellerman check(msi_bitmap_alloc_hwirqs(&bmp, 1) >= 0); 1787e302869SMichael Ellerman 1797e302869SMichael Ellerman check(msi_bitmap_alloc_hwirqs(&bmp, 1) < 0); 1807e302869SMichael Ellerman 1817e302869SMichael Ellerman /* Should all be allocated */ 1827e302869SMichael Ellerman check(bitmap_find_free_region(bmp.bitmap, size, 0) < 0); 1837e302869SMichael Ellerman 1847e302869SMichael Ellerman /* And if we free one we can then allocate another */ 1857e302869SMichael Ellerman msi_bitmap_free_hwirqs(&bmp, size / 2, 1); 1867e302869SMichael Ellerman check(msi_bitmap_alloc_hwirqs(&bmp, 1) == size / 2); 1877e302869SMichael Ellerman 188b0345bbcSIan Munsie /* Check we get a naturally aligned offset */ 189b0345bbcSIan Munsie check(msi_bitmap_alloc_hwirqs(&bmp, 2) % 2 == 0); 190b0345bbcSIan Munsie check(msi_bitmap_alloc_hwirqs(&bmp, 4) % 4 == 0); 191b0345bbcSIan Munsie check(msi_bitmap_alloc_hwirqs(&bmp, 8) % 8 == 0); 192b0345bbcSIan Munsie check(msi_bitmap_alloc_hwirqs(&bmp, 9) % 16 == 0); 193b0345bbcSIan Munsie check(msi_bitmap_alloc_hwirqs(&bmp, 3) % 4 == 0); 194b0345bbcSIan Munsie check(msi_bitmap_alloc_hwirqs(&bmp, 7) % 8 == 0); 195b0345bbcSIan Munsie check(msi_bitmap_alloc_hwirqs(&bmp, 121) % 128 == 0); 196b0345bbcSIan Munsie 1977e302869SMichael Ellerman msi_bitmap_free(&bmp); 1987e302869SMichael Ellerman 1997e302869SMichael Ellerman /* Clients may check bitmap == NULL for "not-allocated" */ 2007e302869SMichael Ellerman check(bmp.bitmap == NULL); 2017e302869SMichael Ellerman 2027e302869SMichael Ellerman kfree(bmp.bitmap); 2037e302869SMichael Ellerman } 2047e302869SMichael Ellerman 205e51df2c1SAnton Blanchard static void __init test_of_node(void) 2067e302869SMichael Ellerman { 2077e302869SMichael Ellerman u32 prop_data[] = { 10, 10, 25, 3, 40, 1, 100, 100, 200, 20 }; 2087e302869SMichael Ellerman const char *expected_str = "0-9,20-24,28-39,41-99,220-255"; 2097e302869SMichael Ellerman char *prop_name = "msi-available-ranges"; 2107e302869SMichael Ellerman char *node_name = "/fakenode"; 2117e302869SMichael Ellerman struct device_node of_node; 2127e302869SMichael Ellerman struct property prop; 2137e302869SMichael Ellerman struct msi_bitmap bmp; 2147e302869SMichael Ellerman int size = 256; 2157e302869SMichael Ellerman DECLARE_BITMAP(expected, size); 2167e302869SMichael Ellerman 2177e302869SMichael Ellerman /* There should really be a struct device_node allocator */ 2187e302869SMichael Ellerman memset(&of_node, 0, sizeof(of_node)); 219e47ff70aSLi Zhong of_node_init(&of_node); 2207e302869SMichael Ellerman of_node.full_name = node_name; 2217e302869SMichael Ellerman 2227e302869SMichael Ellerman check(0 == msi_bitmap_alloc(&bmp, size, &of_node)); 2237e302869SMichael Ellerman 2247e302869SMichael Ellerman /* No msi-available-ranges, so expect > 0 */ 2257e302869SMichael Ellerman check(msi_bitmap_reserve_dt_hwirqs(&bmp) > 0); 2267e302869SMichael Ellerman 2277e302869SMichael Ellerman /* Should all still be free */ 2287e302869SMichael Ellerman check(0 == bitmap_find_free_region(bmp.bitmap, size, 2297e302869SMichael Ellerman get_count_order(size))); 2307e302869SMichael Ellerman bitmap_release_region(bmp.bitmap, 0, get_count_order(size)); 2317e302869SMichael Ellerman 2327e302869SMichael Ellerman /* Now create a fake msi-available-ranges property */ 2337e302869SMichael Ellerman 2347e302869SMichael Ellerman /* There should really .. oh whatever */ 2357e302869SMichael Ellerman memset(&prop, 0, sizeof(prop)); 2367e302869SMichael Ellerman prop.name = prop_name; 2377e302869SMichael Ellerman prop.value = &prop_data; 2387e302869SMichael Ellerman prop.length = sizeof(prop_data); 2397e302869SMichael Ellerman 2407e302869SMichael Ellerman of_node.properties = ∝ 2417e302869SMichael Ellerman 2427e302869SMichael Ellerman /* msi-available-ranges, so expect == 0 */ 2437e302869SMichael Ellerman check(msi_bitmap_reserve_dt_hwirqs(&bmp) == 0); 2447e302869SMichael Ellerman 2457e302869SMichael Ellerman /* Check we got the expected result */ 2467e302869SMichael Ellerman check(0 == bitmap_parselist(expected_str, expected, size)); 2477e302869SMichael Ellerman check(bitmap_equal(expected, bmp.bitmap, size)); 2487e302869SMichael Ellerman 2497e302869SMichael Ellerman msi_bitmap_free(&bmp); 2507e302869SMichael Ellerman kfree(bmp.bitmap); 2517e302869SMichael Ellerman } 2527e302869SMichael Ellerman 253e51df2c1SAnton Blanchard static int __init msi_bitmap_selftest(void) 2547e302869SMichael Ellerman { 2557e302869SMichael Ellerman printk(KERN_DEBUG "Running MSI bitmap self-tests ...\n"); 2567e302869SMichael Ellerman 2577e302869SMichael Ellerman test_basics(); 2587e302869SMichael Ellerman test_of_node(); 2597e302869SMichael Ellerman 2607e302869SMichael Ellerman return 0; 2617e302869SMichael Ellerman } 2627e302869SMichael Ellerman late_initcall(msi_bitmap_selftest); 2637e302869SMichael Ellerman #endif /* CONFIG_MSI_BITMAP_SELFTEST */ 264