/*
* IOMMU implementation for Cell Broadband Processor Architecture
*
* (C) Copyright IBM Corporation 2006-2008
*
* Author: Jeremy Kerr <jk@ozlabs.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, 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., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#undef DEBUG
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/notifier.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/slab.h>
#include <linux/memblock.h>
#include <asm/prom.h>
#include <asm/iommu.h>
#include <asm/machdep.h>
#include <asm/pci-bridge.h>
#include <asm/udbg.h>
#include <asm/firmware.h>
#include <asm/cell-regs.h>
#include "cell.h"
#include "interrupt.h"
/* Define CELL_IOMMU_REAL_UNMAP to actually unmap non-used pages
* instead of leaving them mapped to some dummy page. This can be
* enabled once the appropriate workarounds for spider bugs have
* been enabled
*/
#define CELL_IOMMU_REAL_UNMAP
/* Define CELL_IOMMU_STRICT_PROTECTION to enforce protection of
* IO PTEs based on the transfer direction. That can be enabled
* once spider-net has been fixed to pass the correct direction
* to the DMA mapping functions
*/
#define CELL_IOMMU_STRICT_PROTECTION
#define NR_IOMMUS 2
/* IOC mmap registers */
#define IOC_Reg_Size 0x2000
#define IOC_IOPT_CacheInvd 0x908
#define IOC_IOPT_CacheInvd_NE_Mask 0xffe0000000000000ul
#define IOC_IOPT_CacheInvd_IOPTE_Mask 0x000003fffffffff8ul
#define IOC_IOPT_CacheInvd_Busy 0x0000000000000001ul
#define IOC_IOST_Origin 0x918
#define IOC_IOST_Origin_E 0x8000000000000000ul
#define IOC_IOST_Origin_HW 0x0000000000000800ul
#define IOC_IOST_Origin_HL 0x0000000000000400ul
#define IOC_IO_ExcpStat 0x920
#define IOC_IO_ExcpStat_V 0x8000000000000000ul
#define IOC_IO_ExcpStat_SPF_Mask 0x6000000000000000ul
#define IOC_IO_ExcpStat_SPF_S 0x6000000000000000ul
#define IOC_IO_ExcpStat_SPF_P 0x2000000000000000ul
#define IOC_IO_ExcpStat_ADDR_Mask 0x00000007fffff000ul
#define IOC_IO_ExcpStat_RW_Mask 0x0000000000000800ul
#define IOC_IO_ExcpStat_IOID_Mask 0x00000000000007fful
#define IOC_IO_ExcpMask 0x928
#define IOC_IO_ExcpMask_SFE 0x4000000000000000ul
#define IOC_IO_ExcpMask_PFE 0x2000000000000000ul
#define IOC_IOCmd_Offset 0x1000
#define IOC_IOCmd_Cfg 0xc00
#define IOC_IOCmd_Cfg_TE 0x0000800000000000ul
/* Segment table entries */
#define IOSTE_V 0x8000000000000000ul /* valid */
#define IOSTE_H 0x4000000000000000ul /* cache hint */
#define IOSTE_PT_Base_RPN_Mask 0x3ffffffffffff000ul /* base RPN of IOPT */
#define IOSTE_NPPT_Mask 0x0000000000000fe0ul /* no. pages in IOPT */
#define IOSTE_PS_Mask 0x0000000000000007ul /* page size */
#define IOSTE_PS_4K 0x0000000000000001ul /* - 4kB */
#define IOSTE_PS_64K 0x0000000000000003ul /* - 64kB */
#define IOSTE_PS_1M 0x0000000000000005ul /* - 1MB */
#define IOSTE_PS_16M 0x0000000000000007ul /* - 16MB */
/* IOMMU sizing */
#define IO_SEGMENT_SHIFT 28
#define IO_PAGENO_BITS(shift) (IO_SEGMENT_SHIFT - (shift))
/* The high bit needs to be set on every DMA address */
#define SPIDER_DMA_OFFSET 0x80000000ul
struct iommu_window {
struct list_head list;
struct cbe_iommu *iommu;
unsigned long offset;
unsigned long size;
unsigned int ioid;
struct iommu_table table;
};
#define NAMESIZE 8
struct cbe_iommu {
int nid;
char name[NAMESIZE];
void __iomem *xlate_regs;
void __iomem *cmd_regs;
unsigned long *stab;
unsigned long *ptab;
void *pad_page;
struct list_head windows;
};
/* Static array of iommus, one per node
* each contains a list of windows, keyed from dma_window property
* - on bus setup, look for a matching window, or create one
* - on dev setup, assign iommu_table ptr
*/
static struct cbe_iommu iommus[NR_IOMMUS];
static int cbe_nr_iommus;
static void invalidate_tce_cache(struct cbe_iommu *iommu, unsigned long *pte,
long n_ptes)
{
u64 __iomem *reg;
u64 val;
long n;
reg = iommu->xlate_regs + IOC_IOPT_CacheInvd;
while (n_ptes > 0) {
/* we can invalidate up to 1 << 11 PTEs at once */
n = min(n_ptes, 1l << 11);
val = (((n /*- 1*/) << 53) & IOC_IOPT_CacheInvd_NE_Mask)
| (__pa(pte) & IOC_IOPT_CacheInvd_IOPTE_Mask)
| IOC_IOPT_CacheInvd_Busy;
out_be64(reg, val);
while (in_be64(reg) & IOC_IOPT_CacheInvd_Busy)
;
n_ptes -= n;
pte += n;
}
}
static int tce_build_cell(struct iommu_table *tbl, long index, long npages,
unsigned long uaddr, enum dma_data_direction direction,
struct dma_attrs *attrs)
{
int i;
unsigned long *io_pte, base_pte;
struct iommu_window *window =
container_of(tbl, struct iommu_window, table);
/* implementing proper protection causes problems with the spidernet
* driver - check mapping directions later, but allow read & write by
* default for now.*/
#ifdef CELL_IOMMU_STRICT_PROTECTION
/* to avoid referencing a global, we use a trick here to setup the
* protection bit. "prot" is setup to be 3 fields of 4 bits apprended
* together for each of the 3 supported direction values. It is then
* shifted left so that the fields matching the desired direction
* lands on the appropriate bits, and other bits are masked out.
*/
const unsigned long prot = 0xc48;
base_pte =
((prot << (52 + 4 * direction)) &
(CBE_IOPTE_PP_W | CBE_IOPTE_PP_R)) |
CBE_IOPTE_M | CBE_IOPTE_SO_RW |
(window->ioid & CBE_IOPTE_IOID_Mask);
#else
base_pte = CBE_IOPTE_PP_W | CBE_IOPTE_PP_R | CBE_IOPTE_M |
CBE_IOPTE_SO_RW | (window->ioid & CBE_IOPTE_IOID_Mask);
#endif
if (unlikely(dma_get_attr(DMA_ATTR_WEAK_ORDERING, attrs)))
base_pte &= ~CBE_IOPTE_SO_RW;
io_pte = (unsigned long *)tbl->it_base + (index - tbl->it_offset);
for (i = 0; i < npages; i++, uaddr += (1 << tbl->it_page_shift))
io_pte[i] = base_pte | (__pa(uaddr) & CBE_IOPTE_RPN_Mask);
mb();
invalidate_tce_cache(window->iommu, io_pte, npages);
pr_debug("tce_build_cell(index=%lx,n=%lx,dir=%d,base_pte=%lx)\n",
index, npages, direction, base_pte);
return 0;
}
static void tce_free_cell(struct iommu_table *tbl, long index, long npages)
{
int i;
unsigned long *io_pte, pte;
struct iommu_window *window =
container_of(tbl, struct iommu_window, table);
pr_debug("tce_free_cell(index=%lx,n=%lx)\n", index, npages);
#ifdef CELL_IOMMU_REAL_UNMAP
pte = 0;
#else
/* spider bridge does PCI reads after freeing - insert a mapping
* to a scratch page instead of an invalid entry */
pte = CBE_IOPTE_PP_R | CBE_IOPTE_M | CBE_IOPTE_SO_RW |
__pa(window->iommu->pad_page) |
(window->ioid & CBE_IOPTE_IOID_Mask);
#endif
io_pte = (unsigned long *)tbl->it_base + (index - tbl->it_offset);
for (i = 0; i < npages; i++)
io_pte[i] = pte;
mb();
invalidate_tce_cache(window->iommu, io_pte, npages);
}
static irqreturn_t ioc_interrupt(int irq, void *data)
{
unsigned long stat, spf;
struct cbe_iommu *iommu = data;
stat = in_be64(iommu->xlate_regs + IOC_IO_ExcpStat);
spf = stat & IOC_IO_ExcpStat_SPF_Mask;
/* Might want to rate limit it */
printk(KERN_ERR "iommu: DMA exception 0x%016lx\n", stat);
printk(KERN_ERR " V=%d, SPF=[%c%c], RW=%s, IOID=0x%04x\n",
!!(stat & IOC_IO_ExcpStat_V),
(spf == IOC_IO_ExcpStat_SPF_S) ? 'S' : ' ',
(spf == IOC_IO_ExcpStat_SPF_P) ? 'P' : ' ',
(stat & IOC_IO_ExcpStat_RW_Mask) ? "Read" : "Write",
(unsigned int)(stat & IOC_IO_ExcpStat_IOID_Mask));
printk(KERN_ERR " page=0x%016lx\n",
stat & IOC_IO_ExcpStat_ADDR_Mask);
/* clear interrupt */
stat &= ~IOC_IO_ExcpStat_V;
out_be64(iommu->xlate_regs + IOC_IO_ExcpStat, stat);
return IRQ_HANDLED;
}
static int cell_iommu_find_ioc(int nid, unsigned long *base)
{
struct device_node *np;
struct resource r;
*base = 0;
/* First look for new style /be nodes */
for_each_node_by_name(np, "ioc") {
if (of_node_to_nid(np) != nid)
continue;
if (of_address_to_resource(np, 0, &r)) {
printk(KERN_ERR "iommu: can't get address for %s\n",
np->full_name);
continue;
}
*base = r.start;
of_node_put(np);
return 0;
}
/* Ok, let's try the old way */
for_each_node_by_type(np, "cpu") {
const unsigned int *nidp;
const unsigned long *tmp;
nidp = of_get_property(np, "node-id", NULL);
if (nidp && *nidp == nid) {
tmp = of_get_property(np, "ioc-translation", NULL);
if (tmp) {
*base = *tmp;
of_node_put(np);
return 0;
}
}
}
return -ENODEV;
}
static void cell_iommu_setup_stab(struct cbe_iommu *iommu,
unsigned long dbase, unsigned long dsize,
unsigned long fbase, unsigned long fsize)
{
struct page *page;
unsigned long segments, stab_size;
segments = max(dbase + dsize, fbase + fsize) >> IO_SEGMENT_SHIFT;
pr_debug("%s: iommu[%d]: segments: %lu\n",
__func__, iommu->nid, segments);
/* set up the segment table */
stab_size = segments * sizeof(unsigned long);
page = alloc_pages_node(iommu->nid, GFP_KERNEL, get_order(stab_size));
BUG_ON(!page);
iommu->stab = page_address(page);
memset(iommu->stab, 0, stab_size);
}
static unsigned long *cell_iommu_alloc_ptab(struct cbe_iommu *iommu,
unsigned long base, unsigned long size, unsigned long gap_base,
unsigned long gap_size, unsigned long page_shift)
{
struct page *page;
int i;
unsigned long reg, segments, pages_per_segment, ptab_size,
n_pte_pages, start_seg, *ptab;
start_seg = base >> IO_SEGMENT_SHIFT;
segments = size >> IO_SEGMENT_SHIFT;
pages_per_segment = 1ull << IO_PAGENO_BITS(page_shift);
/* PTEs for each segment must start on a 4K bounday */
pages_per_segment = max(pages_per_segment,
(1 << 12) / sizeof(unsigned long));
ptab_size = segments * pages_per_segment * sizeof(unsigned long);
pr_debug("%s: iommu[%d]: ptab_size: %lu, order: %d\n", __func__,
iommu->nid, ptab_size, get_order(ptab_size));
page = alloc_pages_node(iommu->nid, GFP_KERNEL, get_order(ptab_size));
BUG_ON(!page);
ptab = page_address(page);
memset(ptab, 0, ptab_size);
/* number of 4K pages needed for a page table */
n_pte_pages = (pages_per_segment * sizeof(unsigned long)) >> 12;
pr_debug("%s: iommu[%d]: stab at %p, ptab at %p, n_pte_pages: %lu\n",
__func__, iommu->nid, iommu->stab, ptab,
n_pte_pages);
/* initialise the STEs */
reg = IOSTE_V | ((n_pte_pages - 1) << 5);
switch (page_shift) {
case 12: reg |= IOSTE_PS_4K; break;
case 16: reg |= IOSTE_PS_64K; break;
case 20: reg |= IOSTE_PS_1M; break;
case 24: reg |= IOSTE_PS_16M; break;
default: BUG();
}
gap_base = gap_base >> IO_SEGMENT_SHIFT;
gap_size = gap_size >> IO_SEGMENT_SHIFT;
pr_debug("Setting up IOMMU stab:\n");
for (i = start_seg; i < (start_seg + segments); i++) {
if (i >= gap_base && i < (gap_base + gap_size)) {
pr_debug("\toverlap at %d, skipping\n", i);
continue;
}
iommu->stab[i] = reg | (__pa(ptab) + (n_pte_pages << 12) *
(i - start_seg));
pr_debug("\t[%d] 0x%016lx\n", i, iommu->stab[i]);
}
return ptab;
}
static void cell_iommu_enable_hardware(struct cbe_iommu *iommu)
{
int ret;
unsigned long reg, xlate_base;
unsigned int virq;
if (cell_iommu_find_ioc(iommu->nid, &xlate_base))
panic("%s: missing IOC register mappings for node %d\n",
__func__, iommu->nid);
iommu->xlate_regs = ioremap(xlate_base, IOC_Reg_Size);
iommu->cmd_regs = iommu->xlate_regs + IOC_IOCmd_Offset;
/* ensure that the STEs have updated */
mb();
/* setup interrupts for the iommu. */
reg = in_be64(iommu->xlate_regs + IOC_IO_ExcpStat);
out_be64(iommu->xlate_regs + IOC_IO_ExcpStat,
reg & ~IOC_IO_ExcpStat_V);
out_be64(iommu->xlate_regs + IOC_IO_ExcpMask,
IOC_IO_ExcpMask_PFE | IOC_IO_ExcpMask_SFE);
virq = irq_create_mapping(NULL,
IIC_IRQ_IOEX_ATI | (iommu->nid << IIC_IRQ_NODE_SHIFT));
BUG_ON(virq == NO_IRQ);
ret = request_irq(virq, ioc_interrupt, 0, iommu->name, iommu);
BUG_ON(ret);
/* set the IOC segment table origin register (and turn on the iommu) */
reg = IOC_IOST_Origin_E | __pa(iommu->stab) | IOC_IOST_Origin_HW;
out_be64(iommu->xlate_regs + IOC_IOST_Origin, reg);
in_be64(iommu->xlate_regs + IOC_IOST_Origin);
/* turn on IO translation */
reg = in_be64(iommu->cmd_regs + IOC_IOCmd_Cfg) | IOC_IOCmd_Cfg_TE;
out_be64(iommu->cmd_regs + IOC_IOCmd_Cfg, reg);
}
static void cell_iommu_setup_hardware(struct cbe_iommu *iommu,
unsigned long base, unsigned long size)
{
cell_iommu_setup_stab(iommu, base, size, 0, 0);
iommu->ptab = cell_iommu_alloc_ptab(iommu, base, size, 0, 0,
IOMMU_PAGE_SHIFT_4K);
cell_iommu_enable_hardware(iommu);
}
#if 0/* Unused for now */
static struct iommu_window *find_window(struct cbe_iommu *iommu,
unsigned long offset, unsigned long size)
{
struct iommu_window *window;
/* todo: check for overlapping (but not equal) windows) */
list_for_each_entry(window, &(iommu->windows), list) {
if (window->offset == offset && window->size == size)
return window;
}
return NULL;
}
#endif
static inline u32 cell_iommu_get_ioid(struct device_node *np)
{
const u32 *ioid;
ioid = of_get_property(np, "ioid", NULL);
if (ioid == NULL) {
printk(KERN_WARNING "iommu: missing ioid for %s using 0\n",
np->full_name);
return 0;
}
return *ioid;
}
static struct iommu_table_ops cell_iommu_ops = {
.set = tce_build_cell,
.clear = tce_free_cell
};
static struct iommu_window * __init
cell_iommu_setup_window(struct cbe_iommu *iommu, struct device_node *np,
unsigned long offset, unsigned long size,
unsigned long pte_offset)
{
struct iommu_window *window;
struct page *page;
u32 ioid;
ioid = cell_iommu_get_ioid(np);
window = kzalloc_node(sizeof(*window), GFP_KERNEL, iommu->nid);
BUG_ON(window == NULL);
window->offset = offset;
window->size = size;
window->ioid = ioid;
window->iommu = iommu;
window->table.it_blocksize = 16;
window->table.it_base = (unsigned long)iommu->ptab;
window->table.it_index = iommu->nid;
window->table.it_page_shift = IOMMU_PAGE_SHIFT_4K;
window->table.it_offset =
(offset >> window->table.it_page_shift) + pte_offset;
window->table.it_size = size >> window->table.it_page_shift;
window->table.it_ops = &cell_iommu_ops;
iommu_init_table(&window->table, iommu->nid);
pr_debug("\tioid %d\n", window->ioid);
pr_debug("\tblocksize %ld\n", window->table.it_blocksize);
pr_debug("\tbase 0x%016lx\n", window->table.it_base);
pr_debug("\toffset 0x%lx\n", window->table.it_offset);
pr_debug("\tsize %ld\n", window->table.it_size);
list_add(&window->list, &iommu->windows);
if (offset != 0)
return window;
/* We need to map and reserve the first IOMMU page since it's used
* by the spider workaround. In theory, we only need to do that when
* running on spider but it doesn't really matter.
*
* This code also assumes that we have a window that starts at 0,
* which is the case on all spider based blades.
*/
page = alloc_pages_node(iommu->nid, GFP_KERNEL, 0);
BUG_ON(!page);
iommu->pad_page = page_address(page);
clear_page(iommu->pad_page);
__set_bit(0, window->table.it_map);
tce_build_cell(&window->table, window->table.it_offset, 1,
(unsigned long)iommu->pad_page, DMA_TO_DEVICE, NULL);
return window;
}
static struct cbe_iommu *cell_iommu_for_node(int nid)
{
int i;
for (i = 0; i < cbe_nr_iommus; i++)
if (iommus[i].nid == nid)
return &iommus[i];
return NULL;
}
static unsigned long cell_dma_direct_offset;
static unsigned long dma_iommu_fixed_base;
/* iommu_fixed_is_weak is set if booted with iommu_fixed=weak */
static int iommu_fixed_is_weak;
static struct iommu_table *cell_get_iommu_table(struct device *dev)
{
struct iommu_window *window;
struct cbe_iommu *iommu;
/* Current implementation uses the first window available in that
* node's iommu. We -might- do something smarter later though it may
* never be necessary
*/
iommu = cell_iommu_for_node(dev_to_node(dev));
if (iommu == NULL || list_empty(&iommu->windows)) {
dev_err(dev, "iommu: missing iommu for %s (node %d)\n",
of_node_full_name(dev->of_node), dev_to_node(dev));
return NULL;
}
window = list_entry(iommu->windows.next, struct iommu_window, list);
return &window->table;
}
/* A coherent allocation implies strong ordering */
static void *dma_fixed_alloc_coherent(struct device *dev, size_t size,
dma_addr_t *dma_handle, gfp_t flag,
struct dma_attrs *attrs)
{
if (iommu_fixed_is_weak)
return iommu_alloc_coherent(dev, cell_get_iommu_table(dev),
size, dma_handle,
device_to_mask(dev), flag,
dev_to_node(dev));
else
return dma_direct_ops.alloc(dev, size, dma_handle, flag,
attrs);
}
static void dma_fixed_free_coherent(struct device *dev, size_t size,
void *vaddr, dma_addr_t dma_handle,
struct dma_attrs *attrs)
{
if (iommu_fixed_is_weak)
iommu_free_coherent(cell_get_iommu_table(dev), size, vaddr,
dma_handle);
else
dma_direct_ops.free(dev, size, vaddr, dma_handle, attrs);
}
static dma_addr_t dma_fixed_map_page(struct device *dev, struct page *page,
unsigned long offset, size_t size,
enum dma_data_direction direction,
struct dma_attrs *attrs)
{
if (iommu_fixed_is_weak == dma_get_attr(DMA_ATTR_WEAK_ORDERING, attrs))
return dma_direct_ops.map_page(dev, page, offset, size,
direction, attrs);
else
return iommu_map_page(dev, cell_get_iommu_table(dev), page,
offset, size, device_to_mask(dev),
direction, attrs);
}
static void dma_fixed_unmap_page(struct device *dev, dma_addr_t dma_addr,
size_t size, enum dma_data_direction direction,
struct dma_attrs *attrs)
{
if (iommu_fixed_is_weak == dma_get_attr(DMA_ATTR_WEAK_ORDERING, attrs))
dma_direct_ops.unmap_page(dev, dma_addr, size, direction,
attrs);
else
iommu_unmap_page(cell_get_iommu_table(dev), dma_addr, size,
direction, attrs);
}
static int dma_fixed_map_sg(struct device *dev, struct scatterlist *sg,
int nents, enum dma_data_direction direction,
struct dma_attrs *attrs)
{
if (iommu_fixed_is_weak == dma_get_attr(DMA_ATTR_WEAK_ORDERING, attrs))
return dma_direct_ops.map_sg(dev, sg, nents, direction, attrs);
else
return ppc_iommu_map_sg(dev, cell_get_iommu_table(dev), sg,
nents, device_to_mask(dev),
direction, attrs);
}
static void dma_fixed_unmap_sg(struct device *dev, struct scatterlist *sg,
int nents, enum dma_data_direction direction,
struct dma_attrs *attrs)
{
if (iommu_fixed_is_weak == dma_get_attr(DMA_ATTR_WEAK_ORDERING, attrs))
dma_direct_ops.unmap_sg(dev, sg, nents, direction, attrs);
else
ppc_iommu_unmap_sg(cell_get_iommu_table(dev), sg, nents,
direction, attrs);
}
static int dma_fixed_dma_supported(struct device *dev, u64 mask)
{
return mask == DMA_BIT_MASK(64);
}
static int dma_set_mask_and_switch(struct device *dev, u64 dma_mask);
struct dma_map_ops dma_iommu_fixed_ops = {
.alloc = dma_fixed_alloc_coherent,
.free = dma_fixed_free_coherent,
.map_sg = dma_fixed_map_sg,
.unmap_sg = dma_fixed_unmap_sg,
.dma_supported = dma_fixed_dma_supported,
.set_dma_mask = dma_set_mask_and_switch,
.map_page = dma_fixed_map_page,
.unmap_page = dma_fixed_unmap_page,
};
static void cell_dma_dev_setup_fixed(struct device *dev);
static void cell_dma_dev_setup(struct device *dev)
{
/* Order is important here, these are not mutually exclusive */
if (get_dma_ops(dev) == &dma_iommu_fixed_ops)
cell_dma_dev_setup_fixed(dev);
else if (get_pci_dma_ops() == &dma_iommu_ops)
set_iommu_table_base(dev, cell_get_iommu_table(dev));
else if (get_pci_dma_ops() == &dma_direct_ops)
set_dma_offset(dev, cell_dma_direct_offset);
else
BUG();
}
static void cell_pci_dma_dev_setup(struct pci_dev *dev)
{
cell_dma_dev_setup(&dev->dev);
}
static int cell_of_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;
/* We use the PCI DMA ops */
dev->archdata.dma_ops = get_pci_dma_ops();
cell_dma_dev_setup(dev);
return 0;
}
static struct notifier_block cell_of_bus_notifier = {
.notifier_call = cell_of_bus_notify
};
static int __init cell_iommu_get_window(struct device_node *np,
unsigned long *base,
unsigned long *size)
{
const __be32 *dma_window;
unsigned long index;
/* Use ibm,dma-window if available, else, hard code ! */
dma_window = of_get_property(np, "ibm,dma-window", NULL);
if (dma_window == NULL) {
*base = 0;
*size = 0x80000000u;
return -ENODEV;
}
of_parse_dma_window(np, dma_window, &index, base, size);
return 0;
}
static struct cbe_iommu * __init cell_iommu_alloc(struct device_node *np)
{
struct cbe_iommu *iommu;
int nid, i;
/* Get node ID */
nid = of_node_to_nid(np);
if (nid < 0) {
printk(KERN_ERR "iommu: failed to get node for %s\n",
np->full_name);
return NULL;
}
pr_debug("iommu: setting up iommu for node %d (%s)\n",
nid, np->full_name);
/* XXX todo: If we can have multiple windows on the same IOMMU, which
* isn't the case today, we probably want here to check whether the
* iommu for that node is already setup.
* However, there might be issue with getting the size right so let's
* ignore that for now. We might want to completely get rid of the
* multiple window support since the cell iommu supports per-page ioids
*/
if (cbe_nr_iommus >= NR_IOMMUS) {
printk(KERN_ERR "iommu: too many IOMMUs detected ! (%s)\n",
np->full_name);
return NULL;
}
/* Init base fields */
i = cbe_nr_iommus++;
iommu = &iommus[i];
iommu->stab = NULL;
iommu->nid = nid;
snprintf(iommu->name, sizeof(iommu->name), "iommu%d", i);
INIT_LIST_HEAD(&iommu->windows);
return iommu;
}
static void __init cell_iommu_init_one(struct device_node *np,
unsigned long offset)
{
struct cbe_iommu *iommu;
unsigned long base, size;
iommu = cell_iommu_alloc(np);
if (!iommu)
return;
/* Obtain a window for it */
cell_iommu_get_window(np, &base, &size);
pr_debug("\ttranslating window 0x%lx...0x%lx\n",
base, base + size - 1);
/* Initialize the hardware */
cell_iommu_setup_hardware(iommu, base, size);
/* Setup the iommu_table */
cell_iommu_setup_window(iommu, np, base, size,
offset >> IOMMU_PAGE_SHIFT_4K);
}
static void __init cell_disable_iommus(void)
{
int node;
unsigned long base, val;
void __iomem *xregs, *cregs;
/* Make sure IOC translation is disabled on all nodes */
for_each_online_node(node) {
if (cell_iommu_find_ioc(node, &base))
continue;
xregs = ioremap(base, IOC_Reg_Size);
if (xregs == NULL)
continue;
cregs = xregs + IOC_IOCmd_Offset;
pr_debug("iommu: cleaning up iommu on node %d\n", node);
out_be64(xregs + IOC_IOST_Origin, 0);
(void)in_be64(xregs + IOC_IOST_Origin);
val = in_be64(cregs + IOC_IOCmd_Cfg);
val &= ~IOC_IOCmd_Cfg_TE;
out_be64(cregs + IOC_IOCmd_Cfg, val);
(void)in_be64(cregs + IOC_IOCmd_Cfg);
iounmap(xregs);
}
}
static int __init cell_iommu_init_disabled(void)
{
struct device_node *np = NULL;
unsigned long base = 0, size;
/* When no iommu is present, we use direct DMA ops */
set_pci_dma_ops(&dma_direct_ops);
/* First make sure all IOC translation is turned off */
cell_disable_iommus();
/* If we have no Axon, we set up the spider DMA magic offset */
if (of_find_node_by_name(NULL, "axon") == NULL)
cell_dma_direct_offset = SPIDER_DMA_OFFSET;
/* Now we need to check to see where the memory is mapped
* in PCI space. We assume that all busses use the same dma
* window which is always the case so far on Cell, thus we
* pick up the first pci-internal node we can find and check
* the DMA window from there.
*/
for_each_node_by_name(np, "axon") {
if (np->parent == NULL || np->parent->parent != NULL)
continue;
if (cell_iommu_get_window(np, &base, &size) == 0)
break;
}
if (np == NULL) {
for_each_node_by_name(np, "pci-internal") {
if (np->parent == NULL || np->parent->parent != NULL)
continue;
if (cell_iommu_get_window(np, &base, &size) == 0)
break;
}
}
of_node_put(np);
/* If we found a DMA window, we check if it's big enough to enclose
* all of physical memory. If not, we force enable IOMMU
*/
if (np && size < memblock_end_of_DRAM()) {
printk(KERN_WARNING "iommu: force-enabled, dma window"
" (%ldMB) smaller than total memory (%lldMB)\n",
size >> 20, memblock_end_of_DRAM() >> 20);
return -ENODEV;
}
cell_dma_direct_offset += base;
if (cell_dma_direct_offset != 0)
cell_pci_controller_ops.dma_dev_setup = cell_pci_dma_dev_setup;
printk("iommu: disabled, direct DMA offset is 0x%lx\n",
cell_dma_direct_offset);
return 0;
}
/*
* Fixed IOMMU mapping support
*
* This code adds support for setting up a fixed IOMMU mapping on certain
* cell machines. For 64-bit devices this avoids the performance overhead of
* mapping and unmapping pages at runtime. 32-bit devices are unable to use
* the fixed mapping.
*
* The fixed mapping is established at boot, and maps all of physical memory
* 1:1 into device space at some offset. On machines with < 30 GB of memory
* we setup the fixed mapping immediately above the normal IOMMU window.
*
* For example a machine with 4GB of memory would end up with the normal
* IOMMU window from 0-2GB and the fixed mapping window from 2GB to 6GB. In
* this case a 64-bit device wishing to DMA to 1GB would be told to DMA to
* 3GB, plus any offset required by firmware. The firmware offset is encoded
* in the "dma-ranges" property.
*
* On machines with 30GB or more of memory, we are unable to place the fixed
* mapping above the normal IOMMU window as we would run out of address space.
* Instead we move the normal IOMMU window to coincide with the hash page
* table, this region does not need to be part of the fixed mapping as no
* device should ever be DMA'ing to it. We then setup the fixed mapping
* from 0 to 32GB.
*/
static u64 cell_iommu_get_fixed_address(struct device *dev)
{
u64 cpu_addr, size, best_size, dev_addr = OF_BAD_ADDR;
struct device_node *np;
const u32 *ranges = NULL;
int i, len, best, naddr, nsize, pna, range_size;
np = of_node_get(dev->of_node);
while (1) {
naddr = of_n_addr_cells(np);
nsize = of_n_size_cells(np);
np = of_get_next_parent(np);
if (!np)
break;
ranges = of_get_property(np, "dma-ranges", &len);
/* Ignore empty ranges, they imply no translation required */
if (ranges && len > 0)
break;
}
if (!ranges) {
dev_dbg(dev, "iommu: no dma-ranges found\n");
goto out;
}
len /= sizeof(u32);
pna = of_n_addr_cells(np);
range_size = naddr + nsize + pna;
/* dma-ranges format:
* child addr : naddr cells
* parent addr : pna cells
* size : nsize cells
*/
for (i = 0, best = -1, best_size = 0; i < len; i += range_size) {
cpu_addr = of_translate_dma_address(np, ranges + i + naddr);
size = of_read_number(ranges + i + naddr + pna, nsize);
if (cpu_addr == 0 && size > best_size) {
best = i;
best_size = size;
}
}
if (best >= 0) {
dev_addr = of_read_number(ranges + best, naddr);
} else
dev_dbg(dev, "iommu: no suitable range found!\n");
out:
of_node_put(np);
return dev_addr;
}
static int dma_set_mask_and_switch(struct device *dev, u64 dma_mask)
{
if (!dev->dma_mask || !dma_supported(dev, dma_mask))
return -EIO;
if (dma_mask == DMA_BIT_MASK(64) &&
cell_iommu_get_fixed_address(dev) != OF_BAD_ADDR)
{
dev_dbg(dev, "iommu: 64-bit OK, using fixed ops\n");
set_dma_ops(dev, &dma_iommu_fixed_ops);
} else {
dev_dbg(dev, "iommu: not 64-bit, using default ops\n");
set_dma_ops(dev, get_pci_dma_ops());
}
cell_dma_dev_setup(dev);
*dev->dma_mask = dma_mask;
return 0;
}
static void cell_dma_dev_setup_fixed(struct device *dev)
{
u64 addr;
addr = cell_iommu_get_fixed_address(dev) + dma_iommu_fixed_base;
set_dma_offset(dev, addr);
dev_dbg(dev, "iommu: fixed addr = %llx\n", addr);
}
static void insert_16M_pte(unsigned long addr, unsigned long *ptab,
unsigned long base_pte)
{
unsigned long segment, offset;
segment = addr >> IO_SEGMENT_SHIFT;
offset = (addr >> 24) - (segment << IO_PAGENO_BITS(24));
ptab = ptab + (segment * (1 << 12) / sizeof(unsigned long));
pr_debug("iommu: addr %lx ptab %p segment %lx offset %lx\n",
addr, ptab, segment, offset);
ptab[offset] = base_pte | (__pa(addr) & CBE_IOPTE_RPN_Mask);
}
static void cell_iommu_setup_fixed_ptab(struct cbe_iommu *iommu,
struct device_node *np, unsigned long dbase, unsigned long dsize,
unsigned long fbase, unsigned long fsize)
{
unsigned long base_pte, uaddr, ioaddr, *ptab;
ptab = cell_iommu_alloc_ptab(iommu, fbase, fsize, dbase, dsize, 24);
dma_iommu_fixed_base = fbase;
pr_debug("iommu: mapping 0x%lx pages from 0x%lx\n", fsize, fbase);
base_pte = CBE_IOPTE_PP_W | CBE_IOPTE_PP_R | CBE_IOPTE_M |
(cell_iommu_get_ioid(np) & CBE_IOPTE_IOID_Mask);
if (iommu_fixed_is_weak)
pr_info("IOMMU: Using weak ordering for fixed mapping\n");
else {
pr_info("IOMMU: Using strong ordering for fixed mapping\n");
base_pte |= CBE_IOPTE_SO_RW;
}
for (uaddr = 0; uaddr < fsize; uaddr += (1 << 24)) {
/* Don't touch the dynamic region */
ioaddr = uaddr + fbase;
if (ioaddr >= dbase && ioaddr < (dbase + dsize)) {
pr_debug("iommu: fixed/dynamic overlap, skipping\n");
continue;
}
insert_16M_pte(uaddr, ptab, base_pte);
}
mb();
}
static int __init cell_iommu_fixed_mapping_init(void)
{
unsigned long dbase, dsize, fbase, fsize, hbase, hend;
struct cbe_iommu *iommu;
struct device_node *np;
/* The fixed mapping is only supported on axon machines */
np = of_find_node_by_name(NULL, "axon");
of_node_put(np);
if (!np) {
pr_debug("iommu: fixed mapping disabled, no axons found\n");
return -1;
}
/* We must have dma-ranges properties for fixed mapping to work */
np = of_find_node_with_property(NULL, "dma-ranges");
of_node_put(np);
if (!np) {
pr_debug("iommu: no dma-ranges found, no fixed mapping\n");
return -1;
}
/* The default setup is to have the fixed mapping sit after the
* dynamic region, so find the top of the largest IOMMU window
* on any axon, then add the size of RAM and that's our max value.
* If that is > 32GB we have to do other shennanigans.
*/
fbase = 0;
for_each_node_by_name(np, "axon") {
cell_iommu_get_window(np, &dbase, &dsize);
fbase = max(fbase, dbase + dsize);
}
fbase = _ALIGN_UP(fbase, 1 << IO_SEGMENT_SHIFT);
fsize = memblock_phys_mem_size();
if ((fbase + fsize) <= 0x800000000ul)
hbase = 0; /* use the device tree window */
else {
/* If we're over 32 GB we need to cheat. We can't map all of
* RAM with the fixed mapping, and also fit the dynamic
* region. So try to place the dynamic region where the hash
* table sits, drivers never need to DMA to it, we don't
* need a fixed mapping for that area.
*/
if (!htab_address) {
pr_debug("iommu: htab is NULL, on LPAR? Huh?\n");
return -1;
}
hbase = __pa(htab_address);
hend = hbase + htab_size_bytes;
/* The window must start and end on a segment boundary */
if ((hbase != _ALIGN_UP(hbase, 1 << IO_SEGMENT_SHIFT)) ||
(hend != _ALIGN_UP(hend, 1 << IO_SEGMENT_SHIFT))) {
pr_debug("iommu: hash window not segment aligned\n");
return -1;
}
/* Check the hash window fits inside the real DMA window */
for_each_node_by_name(np, "axon") {
cell_iommu_get_window(np, &dbase, &dsize);
if (hbase < dbase || (hend > (dbase + dsize))) {
pr_debug("iommu: hash window doesn't fit in"
"real DMA window\n");
return -1;
}
}
fbase = 0;
}
/* Setup the dynamic regions */
for_each_node_by_name(np, "axon") {
iommu = cell_iommu_alloc(np);
BUG_ON(!iommu);
if (hbase == 0)
cell_iommu_get_window(np, &dbase, &dsize);
else {
dbase = hbase;
dsize = htab_size_bytes;
}
printk(KERN_DEBUG "iommu: node %d, dynamic window 0x%lx-0x%lx "
"fixed window 0x%lx-0x%lx\n", iommu->nid, dbase,
dbase + dsize, fbase, fbase + fsize);
cell_iommu_setup_stab(iommu, dbase, dsize, fbase, fsize);
iommu->ptab = cell_iommu_alloc_ptab(iommu, dbase, dsize, 0, 0,
IOMMU_PAGE_SHIFT_4K);
cell_iommu_setup_fixed_ptab(iommu, np, dbase, dsize,
fbase, fsize);
cell_iommu_enable_hardware(iommu);
cell_iommu_setup_window(iommu, np, dbase, dsize, 0);
}
dma_iommu_ops.set_dma_mask = dma_set_mask_and_switch;
set_pci_dma_ops(&dma_iommu_ops);
return 0;
}
static int iommu_fixed_disabled;
static int __init setup_iommu_fixed(char *str)
{
struct device_node *pciep;
if (strcmp(str, "off") == 0)
iommu_fixed_disabled = 1;
/* If we can find a pcie-endpoint in the device tree assume that
* we're on a triblade or a CAB so by default the fixed mapping
* should be set to be weakly ordered; but only if the boot
* option WASN'T set for strong ordering
*/
pciep = of_find_node_by_type(NULL, "pcie-endpoint");
if (strcmp(str, "weak") == 0 || (pciep && strcmp(str, "strong") != 0))
iommu_fixed_is_weak = 1;
of_node_put(pciep);
return 1;
}
__setup("iommu_fixed=", setup_iommu_fixed);
static u64 cell_dma_get_required_mask(struct device *dev)
{
struct dma_map_ops *dma_ops;
if (!dev->dma_mask)
return 0;
if (!iommu_fixed_disabled &&
cell_iommu_get_fixed_address(dev) != OF_BAD_ADDR)
return DMA_BIT_MASK(64);
dma_ops = get_dma_ops(dev);
if (dma_ops->get_required_mask)
return dma_ops->get_required_mask(dev);
WARN_ONCE(1, "no get_required_mask in %p ops", dma_ops);
return DMA_BIT_MASK(64);
}
static int __init cell_iommu_init(void)
{
struct device_node *np;
/* If IOMMU is disabled or we have little enough RAM to not need
* to enable it, we setup a direct mapping.
*
* Note: should we make sure we have the IOMMU actually disabled ?
*/
if (iommu_is_off ||
(!iommu_force_on && memblock_end_of_DRAM() <= 0x80000000ull))
if (cell_iommu_init_disabled() == 0)
goto bail;
/* Setup various callbacks */
cell_pci_controller_ops.dma_dev_setup = cell_pci_dma_dev_setup;
ppc_md.dma_get_required_mask = cell_dma_get_required_mask;
if (!iommu_fixed_disabled && cell_iommu_fixed_mapping_init() == 0)
goto bail;
/* Create an iommu for each /axon node. */
for_each_node_by_name(np, "axon") {
if (np->parent == NULL || np->parent->parent != NULL)
continue;
cell_iommu_init_one(np, 0);
}
/* Create an iommu for each toplevel /pci-internal node for
* old hardware/firmware
*/
for_each_node_by_name(np, "pci-internal") {
if (np->parent == NULL || np->parent->parent != NULL)
continue;
cell_iommu_init_one(np, SPIDER_DMA_OFFSET);
}
/* Setup default PCI iommu ops */
set_pci_dma_ops(&dma_iommu_ops);
bail:
/* Register callbacks on OF platform device addition/removal
* to handle linking them to the right DMA operations
*/
bus_register_notifier(&platform_bus_type, &cell_of_bus_notifier);
return 0;
}
machine_arch_initcall(cell, cell_iommu_init);