root/arch/x86/kernel/tce_64.c

DEFINITIONS

1. flush_tce
2. tce_build
3. tce_free
4. table_size_to_number_of_entries
5. tce_table_setparms
6. build_tce_table
7. alloc_tce_table
8. free_tce_table

/*
 * This file manages the translation entries for the IBM Calgary IOMMU.
 *
 * Derived from arch/powerpc/platforms/pseries/iommu.c
 *
 * Copyright (C) IBM Corporation, 2006
 *
 * Author: Jon Mason <jdmason@us.ibm.com>
 * Author: Muli Ben-Yehuda <muli@il.ibm.com>
 *
 * 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/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)
                clflush(tceaddr);
        else
                wbinvd();
}

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 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);

        /*
         * 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 __init build_tce_table(struct pci_dev *dev, void __iomem *bbar)
{
        struct iommu_table *tbl;
        int ret;

        if (pci_iommu(dev->bus)) {
                printk(KERN_ERR "Calgary: dev %p has sysdata->iommu %p\n",
                       dev, pci_iommu(dev->bus));
                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;

        tbl->bbar = bbar;

        set_pci_iommu(dev->bus, tbl);

        return 0;

free_tbl:
        kfree(tbl);
done:
        return ret;
}

void * __init 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 __init 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);
}