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/*
* Contains routines needed to support swiotlb for ppc.
*
* Copyright (C) 2009 Becky Bruce, Freescale Semiconductor
*
* 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.
*
*/
#include <linux/dma-mapping.h>
#include <linux/pfn.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/pci.h>
#include <asm/machdep.h>
#include <asm/swiotlb.h>
#include <asm/dma.h>
#include <asm/abs_addr.h>
int swiotlb __read_mostly;
unsigned int ppc_swiotlb_enable;
void *swiotlb_bus_to_virt(struct device *hwdev, dma_addr_t addr)
{
unsigned long pfn = PFN_DOWN(swiotlb_bus_to_phys(hwdev, addr));
void *pageaddr = page_address(pfn_to_page(pfn));
if (pageaddr != NULL)
return pageaddr + (addr % PAGE_SIZE);
return NULL;
}
dma_addr_t swiotlb_phys_to_bus(struct device *hwdev, phys_addr_t paddr)
{
return paddr + get_dma_direct_offset(hwdev);
}
phys_addr_t swiotlb_bus_to_phys(struct device *hwdev, dma_addr_t baddr)
{
return baddr - get_dma_direct_offset(hwdev);
}
/*
* Determine if an address needs bounce buffering via swiotlb.
* Going forward I expect the swiotlb code to generalize on using
* a dma_ops->addr_needs_map, and this function will move from here to the
* generic swiotlb code.
*/
int
swiotlb_arch_address_needs_mapping(struct device *hwdev, dma_addr_t addr,
size_t size)
{
struct dma_mapping_ops *dma_ops = get_dma_ops(hwdev);
BUG_ON(!dma_ops);
return dma_ops->addr_needs_map(hwdev, addr, size);
}
/*
* Determine if an address is reachable by a pci device, or if we must bounce.
*/
static int
swiotlb_pci_addr_needs_map(struct device *hwdev, dma_addr_t addr, size_t size)
{
u64 mask = dma_get_mask(hwdev);
dma_addr_t max;
struct pci_controller *hose;
struct pci_dev *pdev = to_pci_dev(hwdev);
hose = pci_bus_to_host(pdev->bus);
max = hose->dma_window_base_cur + hose->dma_window_size;
/* check that we're within mapped pci window space */
if ((addr + size > max) | (addr < hose->dma_window_base_cur))
return 1;
return !is_buffer_dma_capable(mask, addr, size);
}
static int
swiotlb_addr_needs_map(struct device *hwdev, dma_addr_t addr, size_t size)
{
return !is_buffer_dma_capable(dma_get_mask(hwdev), addr, size);
}
/*
* At the moment, all platforms that use this code only require
* swiotlb to be used if we're operating on HIGHMEM. Since
* we don't ever call anything other than map_sg, unmap_sg,
* map_page, and unmap_page on highmem, use normal dma_ops
* for everything else.
*/
struct dma_mapping_ops swiotlb_dma_ops = {
.alloc_coherent = dma_direct_alloc_coherent,
.free_coherent = dma_direct_free_coherent,
.map_sg = swiotlb_map_sg_attrs,
.unmap_sg = swiotlb_unmap_sg_attrs,
.dma_supported = swiotlb_dma_supported,
.map_page = swiotlb_map_page,
.unmap_page = swiotlb_unmap_page,
.addr_needs_map = swiotlb_addr_needs_map,
.sync_single_range_for_cpu = swiotlb_sync_single_range_for_cpu,
.sync_single_range_for_device = swiotlb_sync_single_range_for_device,
.sync_sg_for_cpu = swiotlb_sync_sg_for_cpu,
.sync_sg_for_device = swiotlb_sync_sg_for_device
};
struct dma_mapping_ops swiotlb_pci_dma_ops = {
.alloc_coherent = dma_direct_alloc_coherent,
.free_coherent = dma_direct_free_coherent,
.map_sg = swiotlb_map_sg_attrs,
.unmap_sg = swiotlb_unmap_sg_attrs,
.dma_supported = swiotlb_dma_supported,
.map_page = swiotlb_map_page,
.unmap_page = swiotlb_unmap_page,
.addr_needs_map = swiotlb_pci_addr_needs_map,
.sync_single_range_for_cpu = swiotlb_sync_single_range_for_cpu,
.sync_single_range_for_device = swiotlb_sync_single_range_for_device,
.sync_sg_for_cpu = swiotlb_sync_sg_for_cpu,
.sync_sg_for_device = swiotlb_sync_sg_for_device
};
static int ppc_swiotlb_bus_notify(struct notifier_block *nb,
unsigned long action, void *data)
{
struct device *dev = data;
/* We are only intereted in device addition */
if (action != BUS_NOTIFY_ADD_DEVICE)
return 0;
/* May need to bounce if the device can't address all of DRAM */
if (dma_get_mask(dev) < lmb_end_of_DRAM())
set_dma_ops(dev, &swiotlb_dma_ops);
return NOTIFY_DONE;
}
static struct notifier_block ppc_swiotlb_plat_bus_notifier = {
.notifier_call = ppc_swiotlb_bus_notify,
.priority = 0,
};
static struct notifier_block ppc_swiotlb_of_bus_notifier = {
.notifier_call = ppc_swiotlb_bus_notify,
.priority = 0,
};
int __init swiotlb_setup_bus_notifier(void)
{
bus_register_notifier(&platform_bus_type,
&ppc_swiotlb_plat_bus_notifier);
bus_register_notifier(&of_platform_bus_type,
&ppc_swiotlb_of_bus_notifier);
return 0;
}
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