The patch titled
x86-64: Calgary - tighten up the bitmap locking
has been removed from the -mm tree. Its filename was
x86-64-calgary-tighten-up-the-bitmap-locking.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
Subject: x86-64: Calgary - tighten up the bitmap locking
From: Muli Ben-Yehuda <muli@xxxxxxxxxx>
Currently the IOMMU table's lock protects both the bitmap and access
to the hardware's TCE table. Access to the TCE table is synchronized
through the bitmap; therefore, only hold the lock while modifying the
bitmap. This gives a yummy 10-15% reduction in CPU utilization for
netperf on a large SMP machine.
Signed-off-by: Muli Ben-Yehuda <muli@xxxxxxxxxx>
Cc: Andi Kleen <ak@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/x86_64/kernel/pci-calgary.c | 40 ++++++++++++-----------------
1 files changed, 17 insertions(+), 23 deletions(-)
diff -puN arch/x86_64/kernel/pci-calgary.c~x86-64-calgary-tighten-up-the-bitmap-locking arch/x86_64/kernel/pci-calgary.c
--- a/arch/x86_64/kernel/pci-calgary.c~x86-64-calgary-tighten-up-the-bitmap-locking
+++ a/arch/x86_64/kernel/pci-calgary.c
@@ -233,6 +233,7 @@ static void iommu_range_reserve(struct i
unsigned long index;
unsigned long end;
unsigned long badbit;
+ unsigned long flags;
index = start_addr >> PAGE_SHIFT;
@@ -244,6 +245,8 @@ static void iommu_range_reserve(struct i
if (end > tbl->it_size) /* don't go off the table */
end = tbl->it_size;
+ spin_lock_irqsave(&tbl->it_lock, flags);
+
badbit = verify_bit_range(tbl->it_map, 0, index, end);
if (badbit != ~0UL) {
if (printk_ratelimit())
@@ -253,15 +256,20 @@ static void iommu_range_reserve(struct i
}
set_bit_string(tbl->it_map, index, npages);
+
+ spin_unlock_irqrestore(&tbl->it_lock, flags);
}
static unsigned long iommu_range_alloc(struct iommu_table *tbl,
unsigned int npages)
{
+ unsigned long flags;
unsigned long offset;
BUG_ON(npages == 0);
+ spin_lock_irqsave(&tbl->it_lock, flags);
+
offset = find_next_zero_string(tbl->it_map, tbl->it_hint,
tbl->it_size, npages);
if (offset == ~0UL) {
@@ -270,6 +278,7 @@ static unsigned long iommu_range_alloc(s
tbl->it_size, npages);
if (offset == ~0UL) {
printk(KERN_WARNING "Calgary: IOMMU full.\n");
+ spin_unlock_irqrestore(&tbl->it_lock, flags);
if (panic_on_overflow)
panic("Calgary: fix the allocator.\n");
else
@@ -281,17 +290,17 @@ static unsigned long iommu_range_alloc(s
tbl->it_hint = offset + npages;
BUG_ON(tbl->it_hint > tbl->it_size);
+ spin_unlock_irqrestore(&tbl->it_lock, flags);
+
return offset;
}
static dma_addr_t iommu_alloc(struct iommu_table *tbl, void *vaddr,
unsigned int npages, int direction)
{
- unsigned long entry, flags;
+ unsigned long entry;
dma_addr_t ret = bad_dma_address;
- spin_lock_irqsave(&tbl->it_lock, flags);
-
entry = iommu_range_alloc(tbl, npages);
if (unlikely(entry == bad_dma_address))
@@ -304,12 +313,9 @@ static dma_addr_t iommu_alloc(struct iom
tce_build(tbl, entry, npages, (unsigned long)vaddr & PAGE_MASK,
direction);
- spin_unlock_irqrestore(&tbl->it_lock, flags);
-
return ret;
error:
- spin_unlock_irqrestore(&tbl->it_lock, flags);
printk(KERN_WARNING "Calgary: failed to allocate %u pages in "
"iommu %p\n", npages, tbl);
return bad_dma_address;
@@ -321,6 +327,7 @@ static void __iommu_free(struct iommu_ta
unsigned long entry;
unsigned long badbit;
unsigned long badend;
+ unsigned long flags;
/* were we called with bad_dma_address? */
badend = bad_dma_address + (EMERGENCY_PAGES * PAGE_SIZE);
@@ -337,6 +344,8 @@ static void __iommu_free(struct iommu_ta
tce_free(tbl, entry, npages);
+ spin_lock_irqsave(&tbl->it_lock, flags);
+
badbit = verify_bit_range(tbl->it_map, 1, entry, entry + npages);
if (badbit != ~0UL) {
if (printk_ratelimit())
@@ -346,18 +355,14 @@ static void __iommu_free(struct iommu_ta
}
__clear_bit_string(tbl->it_map, entry, npages);
+
+ spin_unlock_irqrestore(&tbl->it_lock, flags);
}
static void iommu_free(struct iommu_table *tbl, dma_addr_t dma_addr,
unsigned int npages)
{
- unsigned long flags;
-
- spin_lock_irqsave(&tbl->it_lock, flags);
-
__iommu_free(tbl, dma_addr, npages);
-
- spin_unlock_irqrestore(&tbl->it_lock, flags);
}
static inline struct iommu_table *find_iommu_table(struct device *dev)
@@ -402,17 +407,12 @@ static void __calgary_unmap_sg(struct io
void calgary_unmap_sg(struct device *dev, struct scatterlist *sglist,
int nelems, int direction)
{
- unsigned long flags;
struct iommu_table *tbl = find_iommu_table(dev);
if (!translate_phb(to_pci_dev(dev)))
return;
- spin_lock_irqsave(&tbl->it_lock, flags);
-
__calgary_unmap_sg(tbl, sglist, nelems, direction);
-
- spin_unlock_irqrestore(&tbl->it_lock, flags);
}
static int calgary_nontranslate_map_sg(struct device* dev,
@@ -433,7 +433,6 @@ int calgary_map_sg(struct device *dev, s
int nelems, int direction)
{
struct iommu_table *tbl = find_iommu_table(dev);
- unsigned long flags;
unsigned long vaddr;
unsigned int npages;
unsigned long entry;
@@ -442,8 +441,6 @@ int calgary_map_sg(struct device *dev, s
if (!translate_phb(to_pci_dev(dev)))
return calgary_nontranslate_map_sg(dev, sg, nelems, direction);
- spin_lock_irqsave(&tbl->it_lock, flags);
-
for (i = 0; i < nelems; i++ ) {
struct scatterlist *s = &sg[i];
BUG_ON(!s->page);
@@ -467,8 +464,6 @@ int calgary_map_sg(struct device *dev, s
s->dma_length = s->length;
}
- spin_unlock_irqrestore(&tbl->it_lock, flags);
-
return nelems;
error:
__calgary_unmap_sg(tbl, sg, nelems, direction);
@@ -476,7 +471,6 @@ error:
sg[i].dma_address = bad_dma_address;
sg[i].dma_length = 0;
}
- spin_unlock_irqrestore(&tbl->it_lock, flags);
return 0;
}
_
Patches currently in -mm which might be from muli@xxxxxxxxxx are
origin.patch
intel-iommu-dmar-detection-and-parsing-logic.patch
intel-iommu-pci-generic-helper-function.patch
intel-iommu-clflush_cache_range-now-takes-size-param.patch
intel-iommu-iova-allocation-and-management-routines.patch
intel-iommu-intel-iommu-driver.patch
intel-iommu-avoid-memory-allocation-failures-in-dma-map-api-calls.patch
intel-iommu-intel-iommu-cmdline-option-forcedac.patch
intel-iommu-dmar-fault-handling-support.patch
intel-iommu-iommu-gfx-workaround.patch
intel-iommu-iommu-floppy-workaround.patch
-
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
