[PATCH] powerpc: map 4K iommu pages even on 64K largepage systems
Benjamin Herrenschmidt
benh at kernel.crashing.org
Tue Oct 24 15:14:27 EST 2006
The 10Gigabit ethernet device drivers appear to be able to chew
up all 256MB of TCE mappings on pSeries systems, as evidenced by
numerous error messages:
iommu_alloc failed, tbl c0000000010d5c48 vaddr c0000000d875eff0 npages 1
Some experimentaiton indicates that this is essentially because
one 1500 byte ethernet MTU gets mapped as a 64K DMA region when
the large 64K pages are enabled. Thus, it doesn't take much to
exhaust all of the available DMA mappings for a high-speed card.
This patch changes the iommu allocator to work with its own
unique, distinct page size. Although the patch is long, its
actually quite simple: it just #defines distinct IOMMU_PAGE_SIZE
and then uses this in al the places tha matter.
The patch boots on pseries, untested in other places.
Haven't yet thought if this is a good long-term solution or not,
whether this kind of thing is desirable or not. That's why its
an RFC. Comments?
Signed-off-by: Linas Vepstas <linas at austin.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh at kernel.crashing.org>
----
And here's a slightly modified version that fixes dart_iommu too and
changes things according to some of my comments.
(I tested on the G5 with and without 64K pages.
arch/powerpc/kernel/iommu.c | 77 +++++++++++++++++++--------------
arch/powerpc/kernel/vio.c | 4 -
arch/powerpc/platforms/pseries/iommu.c | 35 +++------------
arch/powerpc/sysdev/dart.h | 1
arch/powerpc/sysdev/dart_iommu.c | 8 ---
include/asm-powerpc/iommu.h | 22 ++++++++-
include/asm-powerpc/tce.h | 3 -
7 files changed, 78 insertions(+), 72 deletions(-)
Index: linux-cell/arch/powerpc/kernel/iommu.c
===================================================================
--- linux-cell.orig/arch/powerpc/kernel/iommu.c 2006-10-24 14:44:26.000000000 +1000
+++ linux-cell/arch/powerpc/kernel/iommu.c 2006-10-24 14:55:59.000000000 +1000
@@ -47,6 +47,17 @@ static int novmerge = 0;
static int novmerge = 1;
#endif
+static inline unsigned long iommu_num_pages(unsigned long vaddr,
+ unsigned long slen)
+{
+ unsigned long npages;
+
+ npages = IOMMU_PAGE_ALIGN(vaddr + slen) - (vaddr & IOMMU_PAGE_MASK);
+ npages >>= IOMMU_PAGE_SHIFT;
+
+ return npages;
+}
+
static int __init setup_iommu(char *str)
{
if (!strcmp(str, "novmerge"))
@@ -178,10 +189,10 @@ static dma_addr_t iommu_alloc(struct iom
}
entry += tbl->it_offset; /* Offset into real TCE table */
- ret = entry << PAGE_SHIFT; /* Set the return dma address */
+ ret = entry << IOMMU_PAGE_SHIFT; /* Set the return dma address */
/* Put the TCEs in the HW table */
- ppc_md.tce_build(tbl, entry, npages, (unsigned long)page & PAGE_MASK,
+ ppc_md.tce_build(tbl, entry, npages, (unsigned long)page & IOMMU_PAGE_MASK,
direction);
@@ -203,7 +214,7 @@ static void __iommu_free(struct iommu_ta
unsigned long entry, free_entry;
unsigned long i;
- entry = dma_addr >> PAGE_SHIFT;
+ entry = dma_addr >> IOMMU_PAGE_SHIFT;
free_entry = entry - tbl->it_offset;
if (((free_entry + npages) > tbl->it_size) ||
@@ -270,7 +281,7 @@ int iommu_map_sg(struct device *dev, str
/* Init first segment length for backout at failure */
outs->dma_length = 0;
- DBG("mapping %d elements:\n", nelems);
+ DBG("sg mapping %d elements:\n", nelems);
spin_lock_irqsave(&(tbl->it_lock), flags);
@@ -285,9 +296,8 @@ int iommu_map_sg(struct device *dev, str
}
/* Allocate iommu entries for that segment */
vaddr = (unsigned long)page_address(s->page) + s->offset;
- npages = PAGE_ALIGN(vaddr + slen) - (vaddr & PAGE_MASK);
- npages >>= PAGE_SHIFT;
- entry = iommu_range_alloc(tbl, npages, &handle, mask >> PAGE_SHIFT, 0);
+ npages = iommu_num_pages(vaddr, slen);
+ entry = iommu_range_alloc(tbl, npages, &handle, mask >> IOMMU_PAGE_SHIFT, 0);
DBG(" - vaddr: %lx, size: %lx\n", vaddr, slen);
@@ -301,14 +311,14 @@ int iommu_map_sg(struct device *dev, str
/* Convert entry to a dma_addr_t */
entry += tbl->it_offset;
- dma_addr = entry << PAGE_SHIFT;
- dma_addr |= s->offset;
+ dma_addr = entry << IOMMU_PAGE_SHIFT;
+ dma_addr |= (s->offset & ~IOMMU_PAGE_MASK);
- DBG(" - %lx pages, entry: %lx, dma_addr: %lx\n",
+ DBG(" - %lu pages, entry: %lx, dma_addr: %lx\n",
npages, entry, dma_addr);
/* Insert into HW table */
- ppc_md.tce_build(tbl, entry, npages, vaddr & PAGE_MASK, direction);
+ ppc_md.tce_build(tbl, entry, npages, vaddr & IOMMU_PAGE_MASK, direction);
/* If we are in an open segment, try merging */
if (segstart != s) {
@@ -323,7 +333,7 @@ int iommu_map_sg(struct device *dev, str
DBG(" can't merge, new segment.\n");
} else {
outs->dma_length += s->length;
- DBG(" merged, new len: %lx\n", outs->dma_length);
+ DBG(" merged, new len: %ux\n", outs->dma_length);
}
}
@@ -367,9 +377,8 @@ int iommu_map_sg(struct device *dev, str
if (s->dma_length != 0) {
unsigned long vaddr, npages;
- vaddr = s->dma_address & PAGE_MASK;
- npages = (PAGE_ALIGN(s->dma_address + s->dma_length) - vaddr)
- >> PAGE_SHIFT;
+ vaddr = s->dma_address & IOMMU_PAGE_MASK;
+ npages = iommu_num_pages(s->dma_address, s->dma_length);
__iommu_free(tbl, vaddr, npages);
s->dma_address = DMA_ERROR_CODE;
s->dma_length = 0;
@@ -398,8 +407,7 @@ void iommu_unmap_sg(struct iommu_table *
if (sglist->dma_length == 0)
break;
- npages = (PAGE_ALIGN(dma_handle + sglist->dma_length)
- - (dma_handle & PAGE_MASK)) >> PAGE_SHIFT;
+ npages = iommu_num_pages(dma_handle,sglist->dma_length);
__iommu_free(tbl, dma_handle, npages);
sglist++;
}
@@ -532,12 +540,11 @@ dma_addr_t iommu_map_single(struct iommu
BUG_ON(direction == DMA_NONE);
uaddr = (unsigned long)vaddr;
- npages = PAGE_ALIGN(uaddr + size) - (uaddr & PAGE_MASK);
- npages >>= PAGE_SHIFT;
+ npages = iommu_num_pages(uaddr, size);
if (tbl) {
dma_handle = iommu_alloc(tbl, vaddr, npages, direction,
- mask >> PAGE_SHIFT, 0);
+ mask >> IOMMU_PAGE_SHIFT, 0);
if (dma_handle == DMA_ERROR_CODE) {
if (printk_ratelimit()) {
printk(KERN_INFO "iommu_alloc failed, "
@@ -545,7 +552,7 @@ dma_addr_t iommu_map_single(struct iommu
tbl, vaddr, npages);
}
} else
- dma_handle |= (uaddr & ~PAGE_MASK);
+ dma_handle |= (uaddr & ~IOMMU_PAGE_MASK);
}
return dma_handle;
@@ -554,11 +561,14 @@ dma_addr_t iommu_map_single(struct iommu
void iommu_unmap_single(struct iommu_table *tbl, dma_addr_t dma_handle,
size_t size, enum dma_data_direction direction)
{
+ unsigned int npages;
+
BUG_ON(direction == DMA_NONE);
- if (tbl)
- iommu_free(tbl, dma_handle, (PAGE_ALIGN(dma_handle + size) -
- (dma_handle & PAGE_MASK)) >> PAGE_SHIFT);
+ if (tbl) {
+ npages = iommu_num_pages(dma_handle, size);
+ iommu_free(tbl, dma_handle, npages);
+ }
}
/* Allocates a contiguous real buffer and creates mappings over it.
@@ -570,11 +580,11 @@ void *iommu_alloc_coherent(struct iommu_
{
void *ret = NULL;
dma_addr_t mapping;
- unsigned int npages, order;
+ unsigned int order;
+ unsigned int nio_pages, io_order;
struct page *page;
size = PAGE_ALIGN(size);
- npages = size >> PAGE_SHIFT;
order = get_order(size);
/*
@@ -598,8 +608,10 @@ void *iommu_alloc_coherent(struct iommu_
memset(ret, 0, size);
/* Set up tces to cover the allocated range */
- mapping = iommu_alloc(tbl, ret, npages, DMA_BIDIRECTIONAL,
- mask >> PAGE_SHIFT, order);
+ nio_pages = size >> IOMMU_PAGE_SHIFT;
+ io_order = get_iommu_order(size);
+ mapping = iommu_alloc(tbl, ret, nio_pages, DMA_BIDIRECTIONAL,
+ mask >> IOMMU_PAGE_SHIFT, io_order);
if (mapping == DMA_ERROR_CODE) {
free_pages((unsigned long)ret, order);
return NULL;
@@ -611,12 +623,13 @@ void *iommu_alloc_coherent(struct iommu_
void iommu_free_coherent(struct iommu_table *tbl, size_t size,
void *vaddr, dma_addr_t dma_handle)
{
- unsigned int npages;
-
if (tbl) {
+ unsigned int nio_pages;
+
+ size = PAGE_ALIGN(size);
+ nio_pages = size >> IOMMU_PAGE_SHIFT;
+ iommu_free(tbl, dma_handle, nio_pages);
size = PAGE_ALIGN(size);
- npages = size >> PAGE_SHIFT;
- iommu_free(tbl, dma_handle, npages);
free_pages((unsigned long)vaddr, get_order(size));
}
}
Index: linux-cell/include/asm-powerpc/iommu.h
===================================================================
--- linux-cell.orig/include/asm-powerpc/iommu.h 2006-10-24 14:44:26.000000000 +1000
+++ linux-cell/include/asm-powerpc/iommu.h 2006-10-24 14:58:45.000000000 +1000
@@ -22,17 +22,35 @@
#define _ASM_IOMMU_H
#ifdef __KERNEL__
-#include <asm/types.h>
+#include <linux/compiler.h>
#include <linux/spinlock.h>
#include <linux/device.h>
#include <linux/dma-mapping.h>
+#include <asm/types.h>
+#include <asm/bitops.h>
+
+#define IOMMU_PAGE_SHIFT 12
+#define IOMMU_PAGE_SIZE (ASM_CONST(1) << IOMMU_PAGE_SHIFT)
+#define IOMMU_PAGE_MASK (~((1 << IOMMU_PAGE_SHIFT) - 1))
+#define IOMMU_PAGE_ALIGN(addr) _ALIGN_UP(addr, IOMMU_PAGE_SIZE)
+
+#ifndef __ASSEMBLY__
+
+/* Pure 2^n version of get_order */
+static __inline__ __attribute_const__ int get_iommu_order(unsigned long size)
+{
+ return __ilog2((size - 1) >> IOMMU_PAGE_SHIFT) + 1;
+}
+
+#endif /* __ASSEMBLY__ */
+
/*
* IOMAP_MAX_ORDER defines the largest contiguous block
* of dma space we can get. IOMAP_MAX_ORDER = 13
* allows up to 2**12 pages (4096 * 4096) = 16 MB
*/
-#define IOMAP_MAX_ORDER 13
+#define IOMAP_MAX_ORDER 13
struct iommu_table {
unsigned long it_busno; /* Bus number this table belongs to */
Index: linux-cell/include/asm-powerpc/tce.h
===================================================================
--- linux-cell.orig/include/asm-powerpc/tce.h 2006-10-06 13:45:32.000000000 +1000
+++ linux-cell/include/asm-powerpc/tce.h 2006-10-24 14:59:20.000000000 +1000
@@ -22,6 +22,8 @@
#define _ASM_POWERPC_TCE_H
#ifdef __KERNEL__
+#include <asm/iommu.h>
+
/*
* Tces come in two formats, one for the virtual bus and a different
* format for PCI
@@ -33,7 +35,6 @@
#define TCE_SHIFT 12
#define TCE_PAGE_SIZE (1 << TCE_SHIFT)
-#define TCE_PAGE_FACTOR (PAGE_SHIFT - TCE_SHIFT)
#define TCE_ENTRY_SIZE 8 /* each TCE is 64 bits */
Index: linux-cell/arch/powerpc/kernel/vio.c
===================================================================
--- linux-cell.orig/arch/powerpc/kernel/vio.c 2006-10-24 14:44:26.000000000 +1000
+++ linux-cell/arch/powerpc/kernel/vio.c 2006-10-24 14:44:55.000000000 +1000
@@ -92,9 +92,9 @@ static struct iommu_table *vio_build_iom
&tbl->it_index, &offset, &size);
/* TCE table size - measured in tce entries */
- tbl->it_size = size >> PAGE_SHIFT;
+ tbl->it_size = size >> IOMMU_PAGE_SHIFT;
/* offset for VIO should always be 0 */
- tbl->it_offset = offset >> PAGE_SHIFT;
+ tbl->it_offset = offset >> IOMMU_PAGE_SHIFT;
tbl->it_busno = 0;
tbl->it_type = TCE_VB;
Index: linux-cell/arch/powerpc/platforms/pseries/iommu.c
===================================================================
--- linux-cell.orig/arch/powerpc/platforms/pseries/iommu.c 2006-10-24 14:44:26.000000000 +1000
+++ linux-cell/arch/powerpc/platforms/pseries/iommu.c 2006-10-24 15:00:07.000000000 +1000
@@ -57,9 +57,6 @@ static void tce_build_pSeries(struct iom
u64 *tcep;
u64 rpn;
- index <<= TCE_PAGE_FACTOR;
- npages <<= TCE_PAGE_FACTOR;
-
proto_tce = TCE_PCI_READ; // Read allowed
if (direction != DMA_TO_DEVICE)
@@ -82,9 +79,6 @@ static void tce_free_pSeries(struct iomm
{
u64 *tcep;
- npages <<= TCE_PAGE_FACTOR;
- index <<= TCE_PAGE_FACTOR;
-
tcep = ((u64 *)tbl->it_base) + index;
while (npages--)
@@ -95,7 +89,6 @@ static unsigned long tce_get_pseries(str
{
u64 *tcep;
- index <<= TCE_PAGE_FACTOR;
tcep = ((u64 *)tbl->it_base) + index;
return *tcep;
@@ -109,9 +102,6 @@ static void tce_build_pSeriesLP(struct i
u64 proto_tce, tce;
u64 rpn;
- tcenum <<= TCE_PAGE_FACTOR;
- npages <<= TCE_PAGE_FACTOR;
-
rpn = (virt_to_abs(uaddr)) >> TCE_SHIFT;
proto_tce = TCE_PCI_READ;
if (direction != DMA_TO_DEVICE)
@@ -146,7 +136,7 @@ static void tce_buildmulti_pSeriesLP(str
u64 rpn;
long l, limit;
- if (TCE_PAGE_FACTOR == 0 && npages == 1)
+ if (npages == 1)
return tce_build_pSeriesLP(tbl, tcenum, npages, uaddr,
direction);
@@ -164,9 +154,6 @@ static void tce_buildmulti_pSeriesLP(str
__get_cpu_var(tce_page) = tcep;
}
- tcenum <<= TCE_PAGE_FACTOR;
- npages <<= TCE_PAGE_FACTOR;
-
rpn = (virt_to_abs(uaddr)) >> TCE_SHIFT;
proto_tce = TCE_PCI_READ;
if (direction != DMA_TO_DEVICE)
@@ -207,9 +194,6 @@ static void tce_free_pSeriesLP(struct io
{
u64 rc;
- tcenum <<= TCE_PAGE_FACTOR;
- npages <<= TCE_PAGE_FACTOR;
-
while (npages--) {
rc = plpar_tce_put((u64)tbl->it_index, (u64)tcenum << 12, 0);
@@ -229,9 +213,6 @@ static void tce_freemulti_pSeriesLP(stru
{
u64 rc;
- tcenum <<= TCE_PAGE_FACTOR;
- npages <<= TCE_PAGE_FACTOR;
-
rc = plpar_tce_stuff((u64)tbl->it_index, (u64)tcenum << 12, 0, npages);
if (rc && printk_ratelimit()) {
@@ -248,7 +229,6 @@ static unsigned long tce_get_pSeriesLP(s
u64 rc;
unsigned long tce_ret;
- tcenum <<= TCE_PAGE_FACTOR;
rc = plpar_tce_get((u64)tbl->it_index, (u64)tcenum << 12, &tce_ret);
if (rc && printk_ratelimit()) {
@@ -289,7 +269,7 @@ static void iommu_table_setparms(struct
tbl->it_busno = phb->bus->number;
/* Units of tce entries */
- tbl->it_offset = phb->dma_window_base_cur >> PAGE_SHIFT;
+ tbl->it_offset = phb->dma_window_base_cur >> IOMMU_PAGE_SHIFT;
/* Test if we are going over 2GB of DMA space */
if (phb->dma_window_base_cur + phb->dma_window_size > 0x80000000ul) {
@@ -300,7 +280,7 @@ static void iommu_table_setparms(struct
phb->dma_window_base_cur += phb->dma_window_size;
/* Set the tce table size - measured in entries */
- tbl->it_size = phb->dma_window_size >> PAGE_SHIFT;
+ tbl->it_size = phb->dma_window_size >> IOMMU_PAGE_SHIFT;
tbl->it_index = 0;
tbl->it_blocksize = 16;
@@ -325,8 +305,8 @@ static void iommu_table_setparms_lpar(st
tbl->it_base = 0;
tbl->it_blocksize = 16;
tbl->it_type = TCE_PCI;
- tbl->it_offset = offset >> PAGE_SHIFT;
- tbl->it_size = size >> PAGE_SHIFT;
+ tbl->it_offset = offset >> IOMMU_PAGE_SHIFT;
+ tbl->it_size = size >> IOMMU_PAGE_SHIFT;
}
static void iommu_bus_setup_pSeries(struct pci_bus *bus)
@@ -522,8 +502,6 @@ static void iommu_dev_setup_pSeriesLP(st
const void *dma_window = NULL;
struct pci_dn *pci;
- DBG("iommu_dev_setup_pSeriesLP, dev %p (%s)\n", dev, pci_name(dev));
-
/* dev setup for LPAR is a little tricky, since the device tree might
* contain the dma-window properties per-device and not neccesarily
* for the bus. So we need to search upwards in the tree until we
@@ -532,6 +510,9 @@ static void iommu_dev_setup_pSeriesLP(st
*/
dn = pci_device_to_OF_node(dev);
+ DBG("iommu_dev_setup_pSeriesLP, dev %p (%s) %s\n",
+ dev, pci_name(dev), dn->full_name);
+
for (pdn = dn; pdn && PCI_DN(pdn) && !PCI_DN(pdn)->iommu_table;
pdn = pdn->parent) {
dma_window = get_property(pdn, "ibm,dma-window", NULL);
Index: linux-cell/arch/powerpc/sysdev/dart.h
===================================================================
--- linux-cell.orig/arch/powerpc/sysdev/dart.h 2006-10-06 13:47:54.000000000 +1000
+++ linux-cell/arch/powerpc/sysdev/dart.h 2006-10-24 15:01:16.000000000 +1000
@@ -72,7 +72,6 @@
#define DART_PAGE_SHIFT 12
#define DART_PAGE_SIZE (1 << DART_PAGE_SHIFT)
-#define DART_PAGE_FACTOR (PAGE_SHIFT - DART_PAGE_SHIFT)
#endif /* _POWERPC_SYSDEV_DART_H */
Index: linux-cell/arch/powerpc/sysdev/dart_iommu.c
===================================================================
--- linux-cell.orig/arch/powerpc/sysdev/dart_iommu.c 2006-10-24 14:44:26.000000000 +1000
+++ linux-cell/arch/powerpc/sysdev/dart_iommu.c 2006-10-24 15:01:47.000000000 +1000
@@ -156,9 +156,6 @@ static void dart_build(struct iommu_tabl
DBG("dart: build at: %lx, %lx, addr: %x\n", index, npages, uaddr);
- index <<= DART_PAGE_FACTOR;
- npages <<= DART_PAGE_FACTOR;
-
dp = ((unsigned int*)tbl->it_base) + index;
/* On U3, all memory is contigous, so we can move this
@@ -199,9 +196,6 @@ static void dart_free(struct iommu_table
DBG("dart: free at: %lx, %lx\n", index, npages);
- index <<= DART_PAGE_FACTOR;
- npages <<= DART_PAGE_FACTOR;
-
dp = ((unsigned int *)tbl->it_base) + index;
while (npages--)
@@ -281,7 +275,7 @@ 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)) >> DART_PAGE_FACTOR;
+ iommu_table_dart.it_size = dart_tablesize / sizeof(u32);
/* Initialize the common IOMMU code */
iommu_table_dart.it_base = (unsigned long)dart_vbase;
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