[PATCH] x86_64: Calgary IOMMU - Calgary specific bits

This patch hooks Calgary into the build, the x86-64 IOMMU
initialization paths, and introduces the Calgary specific bits.  The
implementation draws inspiration from both PPC (which has support for
the same chip but requires firmware support which we don't have on
x86-64) and gart. Calgary is different from gart in that it support a
translation table per PHB, as opposed to the single gart aperture.

Changes from previous version:
 * Addition of boot-time disablement for bus-level translation/isolation
   (e.g, enable userspace DMA for things like X)
 * Usage of newer IOMMU abstraction functions

Signed-off-by: Muli Ben-Yehuda <muli@il.ibm.com>
Signed-off-by: Jon Mason <jdmason@us.ibm.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 202 insertions, 0 deletions

diff --git a/arch/x86_64/kernel/tce.c b/arch/x86_64/kernel/tce.c
new file mode 100644
index 000000000000..8d4c67f61b8e
--- /dev/null
+++ b/arch/x86_64/kernel/tce.c
@@ -0,0 +1,202 @@
+/*
+ * Derived from arch/powerpc/platforms/pseries/iommu.c
+ *
+ * Copyright (C) 2006 Jon Mason <jdmason@us.ibm.com>, IBM Corporation
+ * Copyright (C) 2006 Muli Ben-Yehuda <muli@il.ibm.com>, 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; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
+ */
+
+#include <linux/config.h>
+#include <linux/types.h>
+#include <linux/slab.h>
+#include <linux/mm.h>
+#include <linux/spinlock.h>
+#include <linux/string.h>
+#include <linux/pci.h>
+#include <linux/dma-mapping.h>
+#include <linux/bootmem.h>
+#include <asm/tce.h>
+#include <asm/calgary.h>
+#include <asm/proto.h>
+
+/* flush a tce at 'tceaddr' to main memory */
+static inline void flush_tce(void* tceaddr)
+{
+        /* a single tce can't cross a cache line */
+        if (cpu_has_clflush)
+                asm volatile("clflush (%0)" :: "r" (tceaddr));
+        else
+                asm volatile("wbinvd":::"memory");
+}
+
+void tce_build(struct iommu_table *tbl, unsigned long index,
+        unsigned int npages, unsigned long uaddr, int direction)
+{
+        u64* tp;
+        u64 t;
+        u64 rpn;
+
+        t = (1 << TCE_READ_SHIFT);
+        if (direction != DMA_TO_DEVICE)
+                t |= (1 << TCE_WRITE_SHIFT);
+
+        tp = ((u64*)tbl->it_base) + index;
+
+        while (npages--) {
+                rpn = (virt_to_bus((void*)uaddr)) >> PAGE_SHIFT;
+                t &= ~TCE_RPN_MASK;
+                t |= (rpn << TCE_RPN_SHIFT);
+
+                *tp = cpu_to_be64(t);
+                flush_tce(tp);
+
+                uaddr += PAGE_SIZE;
+                tp++;
+        }
+}
+
+void tce_free(struct iommu_table *tbl, long index, unsigned int npages)
+{
+        u64* tp;
+
+        tp  = ((u64*)tbl->it_base) + index;
+
+        while (npages--) {
+                *tp = cpu_to_be64(0);
+                flush_tce(tp);
+                tp++;
+        }
+}
+
+static inline unsigned int table_size_to_number_of_entries(unsigned char size)
+{
+        /*
+         * size is the order of the table, 0-7
+         * smallest table is 8K entries, so shift result by 13 to
+         * multiply by 8K
+         */
+        return (1 << size) << 13;
+}
+
+static int tce_table_setparms(struct pci_dev *dev, struct iommu_table *tbl)
+{
+        unsigned int bitmapsz;
+        unsigned int tce_table_index;
+        unsigned long bmppages;
+        int ret;
+
+        tbl->it_busno = dev->bus->number;
+
+        /* set the tce table size - measured in entries */
+        tbl->it_size = table_size_to_number_of_entries(specified_table_size);
+
+        tce_table_index = bus_to_phb(tbl->it_busno);
+        tbl->it_base = (unsigned long)tce_table_kva[tce_table_index];
+        if (!tbl->it_base) {
+                printk(KERN_ERR "Calgary: iommu_table_setparms: "
+                       "no table allocated?!\n");
+                ret = -ENOMEM;
+                goto done;
+        }
+
+        /*
+         * number of bytes needed for the bitmap size in number of
+         * entries; we need one bit per entry
+         */
+        bitmapsz = tbl->it_size / BITS_PER_BYTE;
+        bmppages = __get_free_pages(GFP_KERNEL, get_order(bitmapsz));
+        if (!bmppages) {
+                printk(KERN_ERR "Calgary: cannot allocate bitmap\n");
+                ret = -ENOMEM;
+                goto done;
+        }
+
+        tbl->it_map = (unsigned long*)bmppages;
+
+        memset(tbl->it_map, 0, bitmapsz);
+
+        tbl->it_hint = 0;
+
+        spin_lock_init(&tbl->it_lock);
+
+        return 0;
+
+done:
+        return ret;
+}
+
+int build_tce_table(struct pci_dev *dev, void __iomem *bbar)
+{
+        struct iommu_table *tbl;
+        int ret;
+
+        if (dev->sysdata) {
+                printk(KERN_ERR "Calgary: dev %p has sysdata %p\n",
+                       dev, dev->sysdata);
+                BUG();
+        }
+
+        tbl = kzalloc(sizeof(struct iommu_table), GFP_KERNEL);
+        if (!tbl) {
+                printk(KERN_ERR "Calgary: error allocating iommu_table\n");
+                ret = -ENOMEM;
+                goto done;
+        }
+
+        ret = tce_table_setparms(dev, tbl);
+        if (ret)
+                goto free_tbl;
+
+        tce_free(tbl, 0, tbl->it_size);
+
+        tbl->bbar = bbar;
+
+        /*
+         * NUMA is already using the bus's sysdata pointer, so we use
+         * the bus's pci_dev's sysdata instead.
+         */
+        dev->sysdata = tbl;
+
+        return 0;
+
+free_tbl:
+        kfree(tbl);
+done:
+        return ret;
+}
+
+void* alloc_tce_table(void)
+{
+        unsigned int size;
+
+        size = table_size_to_number_of_entries(specified_table_size);
+        size *= TCE_ENTRY_SIZE;
+
+        return __alloc_bootmem_low(size, size, 0);
+}
+
+void free_tce_table(void *tbl)
+{
+        unsigned int size;
+
+        if (!tbl)
+                return;
+
+        size = table_size_to_number_of_entries(specified_table_size);
+        size *= TCE_ENTRY_SIZE;
+
+        free_bootmem(__pa(tbl), size);
+}