/*
* IOMMU implementation for Broadband Processor Architecture
* We just establish a linear mapping at boot by setting all the
* IOPT cache entries in the CPU.
* The mapping functions should be identical to pci_direct_iommu,
* except for the handling of the high order bit that is required
* by the Spider bridge. These should be split into a separate
* file at the point where we get a different bridge chip.
*
* Copyright (C) 2005 IBM Deutschland Entwicklung GmbH,
* Arnd Bergmann <arndb@de.ibm.com>
*
* Based on linear mapping
* Copyright (C) 2003 Benjamin Herrenschmidt (benh@kernel.crashing.org)
*
* 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.
*/
#undef DEBUG
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/delay.h>
#include <linux/string.h>
#include <linux/init.h>
#include <linux/bootmem.h>
#include <linux/mm.h>
#include <linux/dma-mapping.h>
#include <asm/sections.h>
#include <asm/iommu.h>
#include <asm/io.h>
#include <asm/prom.h>
#include <asm/pci-bridge.h>
#include <asm/machdep.h>
#include <asm/pmac_feature.h>
#include <asm/abs_addr.h>
#include <asm/system.h>
#include "pci.h"
#include "bpa_iommu.h"
static inline unsigned long
get_iopt_entry(unsigned long real_address, unsigned long ioid,
unsigned long prot)
{
return (prot & IOPT_PROT_MASK)
| (IOPT_COHERENT)
| (IOPT_ORDER_VC)
| (real_address & IOPT_RPN_MASK)
| (ioid & IOPT_IOID_MASK);
}
typedef struct {
unsigned long val;
} ioste;
static inline ioste
mk_ioste(unsigned long val)
{
ioste ioste = { .val = val, };
return ioste;
}
static inline ioste
get_iost_entry(unsigned long iopt_base, unsigned long io_address, unsigned page_size)
{
unsigned long ps;
unsigned long iostep;
unsigned long nnpt;
unsigned long shift;
switch (page_size) {
case 0x1000000:
ps = IOST_PS_16M;
nnpt = 0; /* one page per segment */
shift = 5; /* segment has 16 iopt entries */
break;
case 0x100000:
ps = IOST_PS_1M;
nnpt = 0; /* one page per segment */
shift = 1; /* segment has 256 iopt entries */
break;
case 0x10000:
ps = IOST_PS_64K;
nnpt = 0x07; /* 8 pages per io page table */
shift = 0; /* all entries are used */
break;
case 0x1000:
ps = IOST_PS_4K;
nnpt = 0x7f; /* 128 pages per io page table */
shift = 0; /* all entries are used */
break;
default: /* not a known compile time constant */
{
/* BUILD_BUG_ON() is not usable here */
extern void __get_iost_entry_bad_page_size(void);
__get_iost_entry_bad_page_size();
}
break;
}
iostep = iopt_base +
/* need 8 bytes per iopte */
(((io_address / page_size * 8)
/* align io page tables on 4k page boundaries */
<< shift)
/* nnpt+1 pages go into each iopt */
& ~(nnpt << 12));
nnpt++; /* this seems to work, but the documentation is not clear
about wether we put nnpt or nnpt-1 into the ioste bits.
In theory, this can't work for 4k pages. */
return mk_ioste(IOST_VALID_MASK
| (iostep & IOST_PT_BASE_MASK)
| ((nnpt << 5) & IOST_NNPT_MASK)
| (ps & IOST_PS_MASK));
}
/* compute the address of an io pte */
static inline unsigned long
get_ioptep(ioste iost_entry, unsigned long io_address)
{
unsigned long iopt_base;
unsigned long page_size;
unsigned long page_number;
unsigned long iopt_offset;
iopt_base = iost_entry.val & IOST_PT_BASE_MASK;
page_size = iost_entry.val & IOST_PS_MASK;
/* decode page size to compute page number */
page_number = (io_address & 0x0fffffff) >> (10 + 2 * page_size);
/* page number is an offset into the io page table */
iopt_offset = (page_number << 3) & 0x7fff8ul;
return iopt_base + iopt_offset;
}
/* compute the tag field of the iopt cache entry */
static inline unsigned long
get_ioc_tag(ioste iost_entry, unsigned long io_address)
{
unsigned long iopte = get_ioptep(iost_entry, io_address);
return IOPT_VALID_MASK
| ((iopte & 0x00000000000000ff8ul) >> 3)
| ((iopte & 0x0000003fffffc0000ul) >> 9);
}
/* compute the hashed 6 bit index for the 4-way associative pte cache */
static inline unsigned long
get_ioc_hash(ioste iost_entry, unsigned long io_address)
{
unsigned long iopte = get_ioptep(iost_entry, io_address);
return ((iopte & 0x000000000000001f8ul) >> 3)
^ ((iopte & 0x00000000000020000ul) >> 17)
^ ((iopte & 0x00000000000010000ul) >> 15)
^ ((iopte & 0x00000000000008000ul) >> 13)
^ ((iopte & 0x00000000000004000ul) >> 11)
^ ((iopte & 0x00000000000002000ul) >> 9)
^ ((iopte & 0x00000000000001000ul) >> 7);
}
/* same as above, but pretend that we have a simpler 1-way associative
pte cache with an 8 bit index */
static inline unsigned long
get_ioc_hash_1way(ioste iost_entry, unsigned long io_address)
{
unsigned long iopte = get_ioptep(iost_entry, io_address);
return ((iopte & 0x000000000000001f8ul) >> 3)
^ ((iopte & 0x00000000000020000ul) >> 17)
^ ((iopte & 0x00000000000010000ul) >> 15)
^ ((iopte & 0x00000000000008000ul) >> 13)
^ ((iopte & 0x00000000000004000ul) >> 11)
^ ((iopte & 0x00000000000002000ul) >> 9)
^ ((iopte & 0x00000000000001000ul) >> 7)
^ ((iopte & 0x0000000000000c000ul) >> 8);
}
static inline ioste
get_iost_cache(void __iomem *base, unsigned long index)
{
unsigned long __iomem *p = (base + IOC_ST_CACHE_DIR);
return mk_ioste(in_be64(&p[index]));
}
static inline void
set_iost_cache(void __iomem *base, unsigned long index, ioste ste)
{
unsigned long __iomem *p = (base + IOC_ST_CACHE_DIR);
pr_debug("ioste %02lx was %016lx, store %016lx", index,
get_iost_cache(base, index).val, ste.val);
out_be64(&p[index], ste.val);
pr_debug(" now %016lx\n", get_iost_cache(base, index).val);
}
static inline unsigned long
get_iopt_cache(void __iomem *base, unsigned long index, unsigned long *tag)
{
unsigned long __iomem *tags = (void *)(base + IOC_PT_CACHE_DIR);
unsigned long __iomem *p = (void *)(base + IOC_PT_CACHE_REG);
*tag = tags[index];
rmb();
return *p;
}
static inline void
set_iopt_cache(void __iomem *base, unsigned long index,
unsigned long tag, unsigned long val)
{
unsigned long __iomem *tags = base + IOC_PT_CACHE_DIR;
unsigned long __iomem *p = base + IOC_PT_CACHE_REG;
pr_debug("iopt %02lx was v%016lx/t%016lx, store v%016lx/t%016lx\n",
index, get_iopt_cache(base, index, &oldtag), oldtag, val, tag);
out_be64(p, val);
out_be64(&tags[index], tag);
}
static inline void
set_iost_origin(void __iomem *base)
{
unsigned long __iomem *p = base + IOC_ST_ORIGIN;
unsigned long origin = IOSTO_ENABLE | IOSTO_SW;
pr_debug("iost_origin %016lx, now %016lx\n", in_be64(p), origin);
out_be64(p, origin);
}
static inline void
set_iocmd_config(void __iomem *base)
{
unsigned long __iomem *p = base + 0xc00;
unsigned long conf;
conf = in_be64(p);
pr_debug("iost_conf %016lx, now %016lx\n", conf, conf | IOCMD_CONF_TE);
out_be64(p, conf | IOCMD_CONF_TE);
}
/* FIXME: get these from the device tree */
#define ioc_base 0x20000511000ull
#define ioc_mmio_base 0x20000510000ull
#define ioid 0x48a
#define iopt_phys_offset (- 0x20000000) /* We have a 512MB offset from the SB */
#define io_page_size 0x1000000
static unsigned long map_iopt_entry(unsigned long address)
{
switch (address >> 20) {
case 0x600:
address = 0x24020000000ull; /* spider i/o */
break;
default:
address += iopt_phys_offset;
break;
}
return get_iopt_entry(address, ioid, IOPT_PROT_RW);
}
static void iommu_bus_setup_null(struct pci_bus *b) { }
static void iommu_dev_setup_null(struct pci_dev *d) { }
/* initialize the iommu to support a simple linear mapping
* for each DMA window used by any device. For now, we
* happen to know that there is only one DMA window in use,
* starting at iopt_phys_offset. */
static void bpa_map_iommu(void)
{
unsigned long address;
void __iomem *base;
ioste ioste;
unsigned long index;
base = __ioremap(ioc_base, 0x1000, _PAGE_NO_CACHE);
pr_debug("%lx mapped to %p\n", ioc_base, base);
set_iocmd_config(base);
iounmap(base);
base = __ioremap(ioc_mmio_base, 0x1000, _PAGE_NO_CACHE);
pr_debug("%lx mapped to %p\n", ioc_mmio_base, base);
set_iost_origin(base);
for (address = 0; address < 0x100000000ul; address += io_page_size) {
ioste = get_iost_entry(0x10000000000ul, address, io_page_size);
if ((address & 0xfffffff) == 0) /* segment start */
set_iost_cache(base, address >> 28, ioste);
index = get_ioc_hash_1way(ioste, address);
pr_debug("addr %08lx, index %02lx, ioste %016lx\n",
address, index, ioste.val);
set_iopt_cache(base,
get_ioc_hash_1way(ioste, address),
get_ioc_tag(ioste, address),
map_iopt_entry(address));
}
iounmap(base);
}
static void *bpa_alloc_coherent(struct device *hwdev, size_t size,
dma_addr_t *dma_handle, gfp_t flag)
{
void *ret;
ret = (void *)__get_free_pages(flag, get_order(size));
if (ret != NULL) {
memset(ret, 0, size);
*dma_handle = virt_to_abs(ret) | BPA_DMA_VALID;
}
return ret;
}
static void bpa_free_coherent(struct device *hwdev, size_t size,
void *vaddr, dma_addr_t dma_handle)
{
free_pages((unsigned long)vaddr, get_order(size));
}
static dma_addr_t bpa_map_single(struct device *hwdev, void *ptr,
size_t size, enum dma_data_direction direction)
{
return virt_to_abs(ptr) | BPA_DMA_VALID;
}
static void bpa_unmap_single(struct device *hwdev, dma_addr_t dma_addr,
size_t size, enum dma_data_direction direction)
{
}
static int bpa_map_sg(struct device *hwdev, struct scatterlist *sg,
int nents, enum dma_data_direction direction)
{
int i;
for (i = 0; i < nents; i++, sg++) {
sg->dma_address = (page_to_phys(sg->page) + sg->offset)
| BPA_DMA_VALID;
sg->dma_length = sg->length;
}
return nents;
}
static void bpa_unmap_sg(struct device *hwdev, struct scatterlist *sg,
int nents, enum dma_data_direction direction)
{
}
static int bpa_dma_supported(struct device *dev, u64 mask)
{
return mask < 0x100000000ull;
}
void bpa_init_iommu(void)
{
bpa_map_iommu();
/* Direct I/O, IOMMU off */
ppc_md.iommu_dev_setup = iommu_dev_setup_null;
ppc_md.iommu_bus_setup = iommu_bus_setup_null;
pci_dma_ops.alloc_coherent = bpa_alloc_coherent;
pci_dma_ops.free_coherent = bpa_free_coherent;
pci_dma_ops.map_single = bpa_map_single;
pci_dma_ops.unmap_single = bpa_unmap_single;
pci_dma_ops.map_sg = bpa_map_sg;
pci_dma_ops.unmap_sg = bpa_unmap_sg;
pci_dma_ops.dma_supported = bpa_dma_supported;
}
