linux/arch/powerpc/sysdev/dart_iommu.c
Robert Jennings 6490c4903d powerpc/pseries: iommu enablement for CMO
To support Cooperative Memory Overcommitment (CMO), we need to check
for failure from some of the tce hcalls.

These changes for the pseries platform affect the powerpc architecture;
patches for the other affected platforms are included in this patch.

pSeries platform IOMMU code changes:
 * platform TCE functions must handle H_NOT_ENOUGH_RESOURCES errors and
   return an error.

Architecture IOMMU code changes:
 * Calls to ppc_md.tce_build need to check return values and return
   DMA_MAPPING_ERROR for transient errors.

Architecture changes:
 * struct machdep_calls for tce_build*_pSeriesLP functions need to change
   to indicate failure.
 * all other platforms will need updates to iommu functions to match the new
   calling semantics; they will return 0 on success.  The other platforms
   default configs have been built, but no further testing was performed.

Signed-off-by: Robert Jennings <rcj@linux.vnet.ibm.com>
Acked-by: Olof Johansson <olof@lixom.net>
Acked-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2008-07-25 15:44:43 +10:00

423 lines
11 KiB
C

/*
* arch/powerpc/sysdev/dart_iommu.c
*
* Copyright (C) 2004 Olof Johansson <olof@lixom.net>, IBM Corporation
* Copyright (C) 2005 Benjamin Herrenschmidt <benh@kernel.crashing.org>,
* IBM Corporation
*
* Based on pSeries_iommu.c:
* Copyright (C) 2001 Mike Corrigan & Dave Engebretsen, IBM Corporation
* Copyright (C) 2004 Olof Johansson <olof@lixom.net>, IBM Corporation
*
* Dynamic DMA mapping support, Apple U3, U4 & IBM CPC925 "DART" iommu.
*
*
* 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 <linux/vmalloc.h>
#include <linux/suspend.h>
#include <linux/lmb.h>
#include <asm/io.h>
#include <asm/prom.h>
#include <asm/iommu.h>
#include <asm/pci-bridge.h>
#include <asm/machdep.h>
#include <asm/abs_addr.h>
#include <asm/cacheflush.h>
#include <asm/ppc-pci.h>
#include "dart.h"
/* Physical base address and size of the DART table */
unsigned long dart_tablebase; /* exported to htab_initialize */
static unsigned long dart_tablesize;
/* Virtual base address of the DART table */
static u32 *dart_vbase;
#ifdef CONFIG_PM
static u32 *dart_copy;
#endif
/* Mapped base address for the dart */
static unsigned int __iomem *dart;
/* Dummy val that entries are set to when unused */
static unsigned int dart_emptyval;
static struct iommu_table iommu_table_dart;
static int iommu_table_dart_inited;
static int dart_dirty;
static int dart_is_u4;
#define DBG(...)
static inline void dart_tlb_invalidate_all(void)
{
unsigned long l = 0;
unsigned int reg, inv_bit;
unsigned long limit;
DBG("dart: flush\n");
/* To invalidate the DART, set the DARTCNTL_FLUSHTLB bit in the
* control register and wait for it to clear.
*
* Gotcha: Sometimes, the DART won't detect that the bit gets
* set. If so, clear it and set it again.
*/
limit = 0;
inv_bit = dart_is_u4 ? DART_CNTL_U4_FLUSHTLB : DART_CNTL_U3_FLUSHTLB;
retry:
l = 0;
reg = DART_IN(DART_CNTL);
reg |= inv_bit;
DART_OUT(DART_CNTL, reg);
while ((DART_IN(DART_CNTL) & inv_bit) && l < (1L << limit))
l++;
if (l == (1L << limit)) {
if (limit < 4) {
limit++;
reg = DART_IN(DART_CNTL);
reg &= ~inv_bit;
DART_OUT(DART_CNTL, reg);
goto retry;
} else
panic("DART: TLB did not flush after waiting a long "
"time. Buggy U3 ?");
}
}
static inline void dart_tlb_invalidate_one(unsigned long bus_rpn)
{
unsigned int reg;
unsigned int l, limit;
reg = DART_CNTL_U4_ENABLE | DART_CNTL_U4_IONE |
(bus_rpn & DART_CNTL_U4_IONE_MASK);
DART_OUT(DART_CNTL, reg);
limit = 0;
wait_more:
l = 0;
while ((DART_IN(DART_CNTL) & DART_CNTL_U4_IONE) && l < (1L << limit)) {
rmb();
l++;
}
if (l == (1L << limit)) {
if (limit < 4) {
limit++;
goto wait_more;
} else
panic("DART: TLB did not flush after waiting a long "
"time. Buggy U4 ?");
}
}
static void dart_flush(struct iommu_table *tbl)
{
mb();
if (dart_dirty) {
dart_tlb_invalidate_all();
dart_dirty = 0;
}
}
static int dart_build(struct iommu_table *tbl, long index,
long npages, unsigned long uaddr,
enum dma_data_direction direction,
struct dma_attrs *attrs)
{
unsigned int *dp;
unsigned int rpn;
long l;
DBG("dart: build at: %lx, %lx, addr: %x\n", index, npages, uaddr);
dp = ((unsigned int*)tbl->it_base) + index;
/* On U3, all memory is contigous, so we can move this
* out of the loop.
*/
l = npages;
while (l--) {
rpn = virt_to_abs(uaddr) >> DART_PAGE_SHIFT;
*(dp++) = DARTMAP_VALID | (rpn & DARTMAP_RPNMASK);
uaddr += DART_PAGE_SIZE;
}
/* make sure all updates have reached memory */
mb();
in_be32((unsigned __iomem *)dp);
mb();
if (dart_is_u4) {
rpn = index;
while (npages--)
dart_tlb_invalidate_one(rpn++);
} else {
dart_dirty = 1;
}
return 0;
}
static void dart_free(struct iommu_table *tbl, long index, long npages)
{
unsigned int *dp;
/* We don't worry about flushing the TLB cache. The only drawback of
* not doing it is that we won't catch buggy device drivers doing
* bad DMAs, but then no 32-bit architecture ever does either.
*/
DBG("dart: free at: %lx, %lx\n", index, npages);
dp = ((unsigned int *)tbl->it_base) + index;
while (npages--)
*(dp++) = dart_emptyval;
}
static int __init dart_init(struct device_node *dart_node)
{
unsigned int i;
unsigned long tmp, base, size;
struct resource r;
if (dart_tablebase == 0 || dart_tablesize == 0) {
printk(KERN_INFO "DART: table not allocated, using "
"direct DMA\n");
return -ENODEV;
}
if (of_address_to_resource(dart_node, 0, &r))
panic("DART: can't get register base ! ");
/* Make sure nothing from the DART range remains in the CPU cache
* from a previous mapping that existed before the kernel took
* over
*/
flush_dcache_phys_range(dart_tablebase,
dart_tablebase + dart_tablesize);
/* Allocate a spare page to map all invalid DART pages. We need to do
* that to work around what looks like a problem with the HT bridge
* prefetching into invalid pages and corrupting data
*/
tmp = lmb_alloc(DART_PAGE_SIZE, DART_PAGE_SIZE);
dart_emptyval = DARTMAP_VALID | ((tmp >> DART_PAGE_SHIFT) &
DARTMAP_RPNMASK);
/* Map in DART registers */
dart = ioremap(r.start, r.end - r.start + 1);
if (dart == NULL)
panic("DART: Cannot map registers!");
/* Map in DART table */
dart_vbase = ioremap(virt_to_abs(dart_tablebase), dart_tablesize);
/* Fill initial table */
for (i = 0; i < dart_tablesize/4; i++)
dart_vbase[i] = dart_emptyval;
/* Initialize DART with table base and enable it. */
base = dart_tablebase >> DART_PAGE_SHIFT;
size = dart_tablesize >> DART_PAGE_SHIFT;
if (dart_is_u4) {
size &= DART_SIZE_U4_SIZE_MASK;
DART_OUT(DART_BASE_U4, base);
DART_OUT(DART_SIZE_U4, size);
DART_OUT(DART_CNTL, DART_CNTL_U4_ENABLE);
} else {
size &= DART_CNTL_U3_SIZE_MASK;
DART_OUT(DART_CNTL,
DART_CNTL_U3_ENABLE |
(base << DART_CNTL_U3_BASE_SHIFT) |
(size << DART_CNTL_U3_SIZE_SHIFT));
}
/* Invalidate DART to get rid of possible stale TLBs */
dart_tlb_invalidate_all();
printk(KERN_INFO "DART IOMMU initialized for %s type chipset\n",
dart_is_u4 ? "U4" : "U3");
return 0;
}
static void iommu_table_dart_setup(void)
{
iommu_table_dart.it_busno = 0;
iommu_table_dart.it_offset = 0;
/* it_size is in number of entries */
iommu_table_dart.it_size = dart_tablesize / sizeof(u32);
/* Initialize the common IOMMU code */
iommu_table_dart.it_base = (unsigned long)dart_vbase;
iommu_table_dart.it_index = 0;
iommu_table_dart.it_blocksize = 1;
iommu_init_table(&iommu_table_dart, -1);
/* Reserve the last page of the DART to avoid possible prefetch
* past the DART mapped area
*/
set_bit(iommu_table_dart.it_size - 1, iommu_table_dart.it_map);
}
static void pci_dma_dev_setup_dart(struct pci_dev *dev)
{
/* We only have one iommu table on the mac for now, which makes
* things simple. Setup all PCI devices to point to this table
*/
dev->dev.archdata.dma_data = &iommu_table_dart;
}
static void pci_dma_bus_setup_dart(struct pci_bus *bus)
{
struct device_node *dn;
if (!iommu_table_dart_inited) {
iommu_table_dart_inited = 1;
iommu_table_dart_setup();
}
dn = pci_bus_to_OF_node(bus);
if (dn)
PCI_DN(dn)->iommu_table = &iommu_table_dart;
}
void __init iommu_init_early_dart(void)
{
struct device_node *dn;
/* Find the DART in the device-tree */
dn = of_find_compatible_node(NULL, "dart", "u3-dart");
if (dn == NULL) {
dn = of_find_compatible_node(NULL, "dart", "u4-dart");
if (dn == NULL)
goto bail;
dart_is_u4 = 1;
}
/* Setup low level TCE operations for the core IOMMU code */
ppc_md.tce_build = dart_build;
ppc_md.tce_free = dart_free;
ppc_md.tce_flush = dart_flush;
/* Initialize the DART HW */
if (dart_init(dn) == 0) {
ppc_md.pci_dma_dev_setup = pci_dma_dev_setup_dart;
ppc_md.pci_dma_bus_setup = pci_dma_bus_setup_dart;
/* Setup pci_dma ops */
set_pci_dma_ops(&dma_iommu_ops);
return;
}
bail:
/* If init failed, use direct iommu and null setup functions */
ppc_md.pci_dma_dev_setup = NULL;
ppc_md.pci_dma_bus_setup = NULL;
/* Setup pci_dma ops */
set_pci_dma_ops(&dma_direct_ops);
}
#ifdef CONFIG_PM
static void iommu_dart_save(void)
{
memcpy(dart_copy, dart_vbase, 2*1024*1024);
}
static void iommu_dart_restore(void)
{
memcpy(dart_vbase, dart_copy, 2*1024*1024);
dart_tlb_invalidate_all();
}
static int __init iommu_init_late_dart(void)
{
unsigned long tbasepfn;
struct page *p;
/* if no dart table exists then we won't need to save it
* and the area has also not been reserved */
if (!dart_tablebase)
return 0;
tbasepfn = __pa(dart_tablebase) >> PAGE_SHIFT;
register_nosave_region_late(tbasepfn,
tbasepfn + ((1<<24) >> PAGE_SHIFT));
/* For suspend we need to copy the dart contents because
* it is not part of the regular mapping (see above) and
* thus not saved automatically. The memory for this copy
* must be allocated early because we need 2 MB. */
p = alloc_pages(GFP_KERNEL, 21 - PAGE_SHIFT);
BUG_ON(!p);
dart_copy = page_address(p);
ppc_md.iommu_save = iommu_dart_save;
ppc_md.iommu_restore = iommu_dart_restore;
return 0;
}
late_initcall(iommu_init_late_dart);
#endif
void __init alloc_dart_table(void)
{
/* Only reserve DART space if machine has more than 1GB of RAM
* or if requested with iommu=on on cmdline.
*
* 1GB of RAM is picked as limit because some default devices
* (i.e. Airport Extreme) have 30 bit address range limits.
*/
if (iommu_is_off)
return;
if (!iommu_force_on && lmb_end_of_DRAM() <= 0x40000000ull)
return;
/* 512 pages (2MB) is max DART tablesize. */
dart_tablesize = 1UL << 21;
/* 16MB (1 << 24) alignment. We allocate a full 16Mb chuck since we
* will blow up an entire large page anyway in the kernel mapping
*/
dart_tablebase = (unsigned long)
abs_to_virt(lmb_alloc_base(1UL<<24, 1UL<<24, 0x80000000L));
printk(KERN_INFO "DART table allocated at: %lx\n", dart_tablebase);
}