/*
* Copyright (C) 2001 Mike Corrigan & Dave Engebretsen, IBM Corporation
*
* Rewrite, cleanup, new allocation schemes:
* Copyright (C) 2004 Olof Johansson, IBM Corporation
*
* Dynamic DMA mapping support, platform-independent parts.
*
* 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/init.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 <asm/io.h>
#include <asm/prom.h>
#include <asm/iommu.h>
#include <asm/pci-bridge.h>
#include <asm/machdep.h>
#include <asm/ppc-pci.h>
/*
* We can use ->sysdata directly and avoid the extra work in
* pci_device_to_OF_node since ->sysdata will have been initialised
* in the iommu init code for all devices.
*/
#define PCI_GET_DN(dev) ((struct device_node *)((dev)->sysdata))
static inline struct iommu_table *device_to_table(struct device *hwdev)
{
struct pci_dev *pdev;
if (!hwdev) {
pdev = ppc64_isabridge_dev;
if (!pdev)
return NULL;
} else
pdev = to_pci_dev(hwdev);
return PCI_DN(PCI_GET_DN(pdev))->iommu_table;
}
static inline unsigned long device_to_mask(struct device *hwdev)
{
struct pci_dev *pdev;
if (!hwdev) {
pdev = ppc64_isabridge_dev;
if (!pdev) /* This is the best guess we can do */
return 0xfffffffful;
} else
pdev = to_pci_dev(hwdev);
if (pdev->dma_mask)
return pdev->dma_mask;
/* Assume devices without mask can take 32 bit addresses */
return 0xfffffffful;
}
/* Allocates a contiguous real buffer and creates mappings over it.
* Returns the virtual address of the buffer and sets dma_handle
* to the dma address (mapping) of the first page.
*/
static void *pci_iommu_alloc_coherent(struct device *hwdev, size_t size,
dma_addr_t *dma_handle, gfp_t flag)
{
return iommu_alloc_coherent(device_to_table(hwdev), size, dma_handle,
device_to_mask(hwdev), flag,
pcibus_to_node(to_pci_dev(hwdev)->bus));
}
static void pci_iommu_free_coherent(struct device *hwdev, size_t size,
void *vaddr, dma_addr_t dma_handle)
{
iommu_free_coherent(device_to_table(hwdev), size, vaddr, dma_handle);
}
/* Creates TCEs for a user provided buffer. The user buffer must be
* contiguous real kernel storage (not vmalloc). The address of the buffer
* passed here is the kernel (virtual) address of the buffer. The buffer
* need not be page aligned, the dma_addr_t returned will point to the same
* byte within the page as vaddr.
*/
static dma_addr_t pci_iommu_map_single(struct device *hwdev, void *vaddr,
size_t size, enum dma_data_direction direction)
{
return iommu_map_single(device_to_table(hwdev), vaddr, size,
device_to_mask(hwdev), direction);
}
static void pci_iommu_unmap_single(struct device *hwdev, dma_addr_t dma_handle,
size_t size, enum dma_data_direction direction)
{
iommu_unmap_single(device_to_table(hwdev), dma_handle, size, direction);
}
static int pci_iommu_map_sg(struct device *pdev, struct scatterlist *sglist,
int nelems, enum dma_data_direction direction)
{
return iommu_map_sg(pdev, device_to_table(pdev), sglist,
nelems, device_to_mask(pdev), direction);
}
static void pci_iommu_unmap_sg(struct device *pdev, struct scatterlist *sglist,
int nelems, enum dma_data_direction direction)
{
iommu_unmap_sg(device_to_table(pdev), sglist, nelems, direction);
}
/* We support DMA to/from any memory page via the iommu */
static int pci_iommu_dma_supported(struct device *dev, u64 mask)
{
struct iommu_table *tbl = device_to_table(dev);
if (!tbl || tbl->it_offset > mask) {
printk(KERN_INFO "Warning: IOMMU table offset too big for device mask\n");
if (tbl)
printk(KERN_INFO "mask: 0x%08lx, table offset: 0x%08lx\n",
mask, tbl->it_offset);
else
printk(KERN_INFO "mask: 0x%08lx, table unavailable\n",
mask);
return 0;
} else
return 1;
}
struct dma_mapping_ops pci_iommu_ops = {
.alloc_coherent = pci_iommu_alloc_coherent,
.free_coherent = pci_iommu_free_coherent,
.map_single = pci_iommu_map_single,
.unmap_single = pci_iommu_unmap_single,
.map_sg = pci_iommu_map_sg,
.unmap_sg = pci_iommu_unmap_sg,
.dma_supported = pci_iommu_dma_supported,
};
void pci_iommu_init(void)
{
pci_dma_ops = pci_iommu_ops;
}
