diff options
Diffstat (limited to 'arch/powerpc/sysdev/mpic_msi.c')
| -rw-r--r-- | arch/powerpc/sysdev/mpic_msi.c | 183 |
1 files changed, 183 insertions, 0 deletions
diff --git a/arch/powerpc/sysdev/mpic_msi.c b/arch/powerpc/sysdev/mpic_msi.c new file mode 100644 index 00000000000..b076793033c --- /dev/null +++ b/arch/powerpc/sysdev/mpic_msi.c @@ -0,0 +1,183 @@ +/* + * Copyright 2006-2007, 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/irq.h> +#include <linux/bootmem.h> +#include <linux/bitmap.h> +#include <linux/msi.h> +#include <asm/mpic.h> +#include <asm/prom.h> +#include <asm/hw_irq.h> +#include <asm/ppc-pci.h> + + +static void __mpic_msi_reserve_hwirq(struct mpic *mpic, irq_hw_number_t hwirq) +{ + pr_debug("mpic: reserving hwirq 0x%lx\n", hwirq); + bitmap_allocate_region(mpic->hwirq_bitmap, hwirq, 0); +} + +void mpic_msi_reserve_hwirq(struct mpic *mpic, irq_hw_number_t hwirq) +{ + unsigned long flags; + + /* The mpic calls this even when there is no allocator setup */ + if (!mpic->hwirq_bitmap) + return; + + spin_lock_irqsave(&mpic->bitmap_lock, flags); + __mpic_msi_reserve_hwirq(mpic, hwirq); + spin_unlock_irqrestore(&mpic->bitmap_lock, flags); +} + +irq_hw_number_t mpic_msi_alloc_hwirqs(struct mpic *mpic, int num) +{ + unsigned long flags; + int offset, order = get_count_order(num); + + spin_lock_irqsave(&mpic->bitmap_lock, flags); + /* + * This is fast, but stricter than we need. We might want to add + * a fallback routine which does a linear search with no alignment. + */ + offset = bitmap_find_free_region(mpic->hwirq_bitmap, mpic->irq_count, + order); + spin_unlock_irqrestore(&mpic->bitmap_lock, flags); + + pr_debug("mpic: allocated 0x%x (2^%d) at offset 0x%x\n", + num, order, offset); + + return offset; +} + +void mpic_msi_free_hwirqs(struct mpic *mpic, int offset, int num) +{ + unsigned long flags; + int order = get_count_order(num); + + pr_debug("mpic: freeing 0x%x (2^%d) at offset 0x%x\n", + num, order, offset); + + spin_lock_irqsave(&mpic->bitmap_lock, flags); + bitmap_release_region(mpic->hwirq_bitmap, offset, order); + spin_unlock_irqrestore(&mpic->bitmap_lock, flags); +} + +#ifdef CONFIG_MPIC_U3_HT_IRQS +static int mpic_msi_reserve_u3_hwirqs(struct mpic *mpic) +{ + irq_hw_number_t hwirq; + struct irq_host_ops *ops = mpic->irqhost->ops; + struct device_node *np; + int flags, index, i; + struct of_irq oirq; + + pr_debug("mpic: found U3, guessing msi allocator setup\n"); + + /* Reserve source numbers we know are reserved in the HW */ + for (i = 0; i < 8; i++) + __mpic_msi_reserve_hwirq(mpic, i); + + for (i = 42; i < 46; i++) + __mpic_msi_reserve_hwirq(mpic, i); + + for (i = 100; i < 105; i++) + __mpic_msi_reserve_hwirq(mpic, i); + + np = NULL; + while ((np = of_find_all_nodes(np))) { + pr_debug("mpic: mapping hwirqs for %s\n", np->full_name); + + index = 0; + while (of_irq_map_one(np, index++, &oirq) == 0) { + ops->xlate(mpic->irqhost, NULL, oirq.specifier, + oirq.size, &hwirq, &flags); + __mpic_msi_reserve_hwirq(mpic, hwirq); + } + } + + return 0; +} +#else +static int mpic_msi_reserve_u3_hwirqs(struct mpic *mpic) +{ + return -1; +} +#endif + +static int mpic_msi_reserve_dt_hwirqs(struct mpic *mpic) +{ + int i, len; + const u32 *p; + + p = of_get_property(mpic->of_node, "msi-available-ranges", &len); + if (!p) { + pr_debug("mpic: no msi-available-ranges property found on %s\n", + mpic->of_node->full_name); + return -ENODEV; + } + + if (len % 8 != 0) { + printk(KERN_WARNING "mpic: Malformed msi-available-ranges " + "property on %s\n", mpic->of_node->full_name); + return -EINVAL; + } + + bitmap_allocate_region(mpic->hwirq_bitmap, 0, + get_count_order(mpic->irq_count)); + + /* Format is: (<u32 start> <u32 count>)+ */ + len /= sizeof(u32); + for (i = 0; i < len / 2; i++, p += 2) + mpic_msi_free_hwirqs(mpic, *p, *(p + 1)); + + return 0; +} + +int mpic_msi_init_allocator(struct mpic *mpic) +{ + int rc, size; + + BUG_ON(mpic->hwirq_bitmap); + spin_lock_init(&mpic->bitmap_lock); + + size = BITS_TO_LONGS(mpic->irq_count) * sizeof(long); + pr_debug("mpic: allocator bitmap size is 0x%x bytes\n", size); + + if (mem_init_done) + mpic->hwirq_bitmap = kmalloc(size, GFP_KERNEL); + else + mpic->hwirq_bitmap = alloc_bootmem(size); + + if (!mpic->hwirq_bitmap) { + pr_debug("mpic: ENOMEM allocating allocator bitmap!\n"); + return -ENOMEM; + } + + memset(mpic->hwirq_bitmap, 0, size); + + rc = mpic_msi_reserve_dt_hwirqs(mpic); + if (rc) { + if (mpic->flags & MPIC_U3_HT_IRQS) + rc = mpic_msi_reserve_u3_hwirqs(mpic); + + if (rc) + goto out_free; + } + + return 0; + + out_free: + if (mem_init_done) + kfree(mpic->hwirq_bitmap); + + mpic->hwirq_bitmap = NULL; + return rc; +} |