/*
* VFIO: IOMMU DMA mapping support for TCE on POWER
*
* Copyright (C) 2013 IBM Corp. All rights reserved.
* Author: Alexey Kardashevskiy <aik@ozlabs.ru>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* Derived from original vfio_iommu_type1.c:
* Copyright (C) 2012 Red Hat, Inc. All rights reserved.
* Author: Alex Williamson <alex.williamson@redhat.com>
*/
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/slab.h>
#include <linux/uaccess.h>
#include <linux/err.h>
#include <linux/vfio.h>
#include <linux/vmalloc.h>
#include <asm/iommu.h>
#include <asm/tce.h>
#include <asm/mmu_context.h>
#define DRIVER_VERSION "0.1"
#define DRIVER_AUTHOR "aik@ozlabs.ru"
#define DRIVER_DESC "VFIO IOMMU SPAPR TCE"
static void tce_iommu_detach_group(void *iommu_data,
struct iommu_group *iommu_group);
static long try_increment_locked_vm(long npages)
{
long ret = 0, locked, lock_limit;
if (!current || !current->mm)
return -ESRCH; /* process exited */
if (!npages)
return 0;
down_write(¤t->mm->mmap_sem);
locked = current->mm->locked_vm + npages;
lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
if (locked > lock_limit && !capable(CAP_IPC_LOCK))
ret = -ENOMEM;
else
current->mm->locked_vm += npages;
pr_debug("[%d] RLIMIT_MEMLOCK +%ld %ld/%ld%s\n", current->pid,
npages << PAGE_SHIFT,
current->mm->locked_vm << PAGE_SHIFT,
rlimit(RLIMIT_MEMLOCK),
ret ? " - exceeded" : "");
up_write(¤t->mm->mmap_sem);
return ret;
}
static void decrement_locked_vm(long npages)
{
if (!current || !current->mm || !npages)
return; /* process exited */
down_write(¤t->mm->mmap_sem);
if (WARN_ON_ONCE(npages > current->mm->locked_vm))
npages = current->mm->locked_vm;
current->mm->locked_vm -= npages;
pr_debug("[%d] RLIMIT_MEMLOCK -%ld %ld/%ld\n", current->pid,
npages << PAGE_SHIFT,
current->mm->locked_vm << PAGE_SHIFT,
rlimit(RLIMIT_MEMLOCK));
up_write(¤t->mm->mmap_sem);
}
/*
* VFIO IOMMU fd for SPAPR_TCE IOMMU implementation
*
* This code handles mapping and unmapping of user data buffers
* into DMA'ble space using the IOMMU
*/
struct tce_iommu_group {
struct list_head next;
struct iommu_group *grp;
};
/*
* The container descriptor supports only a single group per container.