]> www.pilppa.org Git - linux-2.6-omap-h63xx.git/commitdiff
[POWERPC] MPIC MSI allocator
authorMichael Ellerman <michael@ellerman.id.au>
Tue, 8 May 2007 02:58:36 +0000 (12:58 +1000)
committerPaul Mackerras <paulus@samba.org>
Tue, 8 May 2007 03:43:48 +0000 (13:43 +1000)
To support MSI on MPIC we need a way to reserve and allocate hardware irq
numbers, this patch implements an allocator for that purpose.

New firmware platforms must define a "msi-available-ranges" property on their
MPIC node for MSI to work. For U3/U4 we do a best-guess setup.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
arch/powerpc/sysdev/Makefile
arch/powerpc/sysdev/mpic.c
arch/powerpc/sysdev/mpic.h [new file with mode: 0644]
arch/powerpc/sysdev/mpic_msi.c [new file with mode: 0644]
include/asm-powerpc/mpic.h

index e96ca9618dbb39541d42973aa4ae1528b3929cd2..a1702053297bf590f91b102dfe6f3c93ec6e10bb 100644 (file)
@@ -2,7 +2,9 @@ ifeq ($(CONFIG_PPC64),y)
 EXTRA_CFLAGS                   += -mno-minimal-toc
 endif
 
-obj-$(CONFIG_MPIC)             += mpic.o
+mpic-msi-obj-$(CONFIG_PCI_MSI) += mpic_msi.o
+obj-$(CONFIG_MPIC)             += mpic.o $(mpic-msi-obj-y)
+
 obj-$(CONFIG_PPC_INDIRECT_PCI) += indirect_pci.o
 obj-$(CONFIG_PPC_MPC106)       += grackle.o
 obj-$(CONFIG_PPC_DCR)          += dcr.o
index 33ecf89702d48aac072f1a5b167553472f6ff37a..fc0428aea0c04f229b9901165e79f2e12c77e7db 100644 (file)
@@ -36,6 +36,8 @@
 #include <asm/mpic.h>
 #include <asm/smp.h>
 
+#include "mpic.h"
+
 #ifdef DEBUG
 #define DBG(fmt...) printk(fmt)
 #else
@@ -891,6 +893,8 @@ static int mpic_host_map(struct irq_host *h, unsigned int virq,
        if (hw >= mpic->irq_count)
                return -EINVAL;
 
+       mpic_msi_reserve_hwirq(mpic, hw);
+
        /* Default chip */
        chip = &mpic->hc_irq;
 
diff --git a/arch/powerpc/sysdev/mpic.h b/arch/powerpc/sysdev/mpic.h
new file mode 100644 (file)
index 0000000..87cb2ae
--- /dev/null
@@ -0,0 +1,27 @@
+#ifndef _POWERPC_SYSDEV_MPIC_H
+#define _POWERPC_SYSDEV_MPIC_H
+
+/*
+ * 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.
+ *
+ */
+
+#ifdef CONFIG_PCI_MSI
+extern void mpic_msi_reserve_hwirq(struct mpic *mpic, irq_hw_number_t hwirq);
+extern int mpic_msi_init_allocator(struct mpic *mpic);
+extern irq_hw_number_t mpic_msi_alloc_hwirqs(struct mpic *mpic, int num);
+extern void mpic_msi_free_hwirqs(struct mpic *mpic, int offset, int num);
+#else
+static inline void mpic_msi_reserve_hwirq(struct mpic *mpic,
+                                         irq_hw_number_t hwirq)
+{
+       return;
+}
+#endif
+
+#endif /* _POWERPC_SYSDEV_MPIC_H */
diff --git a/arch/powerpc/sysdev/mpic_msi.c b/arch/powerpc/sysdev/mpic_msi.c
new file mode 100644 (file)
index 0000000..b076793
--- /dev/null
@@ -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;
+}
index 22c85c4f5b29b8719df4143ef3d1b98d95e20fc4..2ffb06abe881c703d98347ee3bf9c0f0528a35c2 100644 (file)
@@ -301,6 +301,11 @@ struct mpic
        u32                     *hw_set;
 #endif
 
+#ifdef CONFIG_PCI_MSI
+       spinlock_t              bitmap_lock;
+       unsigned long           *hwirq_bitmap;
+#endif
+
        /* link */
        struct mpic             *next;