Commit ec3cf2ec authored by Becky Bruce's avatar Becky Bruce Committed by Benjamin Herrenschmidt

powerpc: Add support for swiotlb on 32-bit

This patch includes the basic infrastructure to use swiotlb
bounce buffering on 32-bit powerpc.  It is not yet enabled on
any platforms.  Probably the most interesting bit is the
addition of addr_needs_map to dma_ops - we need this as
a dma_op because the decision of whether or not an addr
can be mapped by a device is device-specific.
Signed-off-by: default avatarBecky Bruce <beckyb@kernel.crashing.org>
Acked-by: default avatarKumar Gala <galak@kernel.crashing.org>
Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
parent 1babddbc
......@@ -300,9 +300,19 @@ config IOMMU_VMERGE
config IOMMU_HELPER
def_bool PPC64
config SWIOTLB
bool "SWIOTLB support"
default n
select IOMMU_HELPER
---help---
Support for IO bounce buffering for systems without an IOMMU.
This allows us to DMA to the full physical address space on
platforms where the size of a physical address is larger
than the bus address. Not all platforms support this.
config PPC_NEED_DMA_SYNC_OPS
def_bool y
depends on NOT_COHERENT_CACHE
depends on (NOT_COHERENT_CACHE || SWIOTLB)
config HOTPLUG_CPU
bool "Support for enabling/disabling CPUs"
......
......@@ -15,9 +15,18 @@
#include <linux/scatterlist.h>
#include <linux/dma-attrs.h>
#include <asm/io.h>
#include <asm/swiotlb.h>
#define DMA_ERROR_CODE (~(dma_addr_t)0x0)
/* Some dma direct funcs must be visible for use in other dma_ops */
extern void *dma_direct_alloc_coherent(struct device *dev, size_t size,
dma_addr_t *dma_handle, gfp_t flag);
extern void dma_direct_free_coherent(struct device *dev, size_t size,
void *vaddr, dma_addr_t dma_handle);
extern unsigned long get_dma_direct_offset(struct device *dev);
#ifdef CONFIG_NOT_COHERENT_CACHE
/*
* DMA-consistent mapping functions for PowerPCs that don't support
......@@ -78,6 +87,8 @@ struct dma_mapping_ops {
dma_addr_t dma_address, size_t size,
enum dma_data_direction direction,
struct dma_attrs *attrs);
int (*addr_needs_map)(struct device *dev, dma_addr_t addr,
size_t size);
#ifdef CONFIG_PPC_NEED_DMA_SYNC_OPS
void (*sync_single_range_for_cpu)(struct device *hwdev,
dma_addr_t dma_handle, unsigned long offset,
......
/*
* 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.
*
*/
#ifndef __ASM_SWIOTLB_H
#define __ASM_SWIOTLB_H
#include <linux/swiotlb.h>
extern struct dma_mapping_ops swiotlb_dma_ops;
extern struct dma_mapping_ops swiotlb_pci_dma_ops;
int swiotlb_arch_address_needs_mapping(struct device *, dma_addr_t,
size_t size);
static inline void dma_mark_clean(void *addr, size_t size) {}
extern unsigned int ppc_swiotlb_enable;
int __init swiotlb_setup_bus_notifier(void);
#endif /* __ASM_SWIOTLB_H */
......@@ -82,6 +82,7 @@ obj-$(CONFIG_SMP) += smp.o
obj-$(CONFIG_KPROBES) += kprobes.o
obj-$(CONFIG_PPC_UDBG_16550) += legacy_serial.o udbg_16550.o
obj-$(CONFIG_STACKTRACE) += stacktrace.o
obj-$(CONFIG_SWIOTLB) += dma-swiotlb.o
pci64-$(CONFIG_PPC64) += pci_dn.o isa-bridge.o
obj-$(CONFIG_PCI) += pci_$(CONFIG_WORD_SIZE).o $(pci64-y) \
......
/*
* 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;
}
......@@ -19,7 +19,7 @@
* default the offset is PCI_DRAM_OFFSET.
*/
static unsigned long get_dma_direct_offset(struct device *dev)
unsigned long get_dma_direct_offset(struct device *dev)
{
if (dev)
return (unsigned long)dev->archdata.dma_data;
......
......@@ -39,6 +39,7 @@
#include <asm/serial.h>
#include <asm/udbg.h>
#include <asm/mmu_context.h>
#include <asm/swiotlb.h>
#include "setup.h"
......@@ -332,6 +333,11 @@ void __init setup_arch(char **cmdline_p)
ppc_md.setup_arch();
if ( ppc_md.progress ) ppc_md.progress("arch: exit", 0x3eab);
#ifdef CONFIG_SWIOTLB
if (ppc_swiotlb_enable)
swiotlb_init();
#endif
paging_init();
/* Initialize the MMU context management stuff */
......
......@@ -61,6 +61,7 @@
#include <asm/xmon.h>
#include <asm/udbg.h>
#include <asm/kexec.h>
#include <asm/swiotlb.h>
#include "setup.h"
......@@ -527,6 +528,11 @@ void __init setup_arch(char **cmdline_p)
if (ppc_md.setup_arch)
ppc_md.setup_arch();
#ifdef CONFIG_SWIOTLB
if (ppc_swiotlb_enable)
swiotlb_init();
#endif
paging_init();
ppc64_boot_msg(0x15, "Setup Done");
}
......
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