Movatterモバイル変換

[0]ホーム
URL:

Skip to content

Navigation Menu

Sign in
Appearance settings

Search code, repositories, users, issues, pull requests...

Provide feedback

We read every piece of feedback, and take your input very seriously.

Saved searches

Use saved searches to filter your results more quickly

 Sign up
Appearance settings

Commit5927145

Browse files
Christoph HellwigIngo Molnar
Christoph Hellwig
authored and
Ingo Molnar
committed
x86/cpu: Remove the CONFIG_X86_PPRO_FENCE=y quirk
There were only a few Pentium Pro multiprocessors systems where thiserrata applied. They are more than 20 years old now, and we've slowlydropped places which put the workarounds in and discouraged anyonefrom enabling the workaround.Get rid of it for good.Tested-by: Tom Lendacky <thomas.lendacky@amd.com>Signed-off-by: Christoph Hellwig <hch@lst.de>Reviewed-by: Thomas Gleixner <tglx@linutronix.de>Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>Cc: David Woodhouse <dwmw2@infradead.org>Cc: Joerg Roedel <joro@8bytes.org>Cc: Jon Mason <jdmason@kudzu.us>Cc: Linus Torvalds <torvalds@linux-foundation.org>Cc: Muli Ben-Yehuda <mulix@mulix.org>Cc: Peter Zijlstra <peterz@infradead.org>Cc: iommu@lists.linux-foundation.orgLink:http://lkml.kernel.org/r/20180319103826.12853-2-hch@lst.deSigned-off-by: Ingo Molnar <mingo@kernel.org>
1 parentc55b855 commit5927145

File tree

6 files changed

+0
-83
lines changed

6 files changed

+0
-83
lines changed

‎arch/x86/Kconfig.cpu‎

Lines changed: 0 additions & 13 deletions
Original file line numberDiff line numberDiff line change
@@ -315,19 +315,6 @@ config X86_L1_CACHE_SHIFT
315315
default "4" if MELAN || M486 || MGEODEGX1
316316
default "5" if MWINCHIP3D || MWINCHIPC6 || MCRUSOE || MEFFICEON || MCYRIXIII || MK6 || MPENTIUMIII || MPENTIUMII || M686 || M586MMX || M586TSC || M586 || MVIAC3_2 || MGEODE_LX
317317

318-
config X86_PPRO_FENCE
319-
bool "PentiumPro memory ordering errata workaround"
320-
depends on M686 || M586MMX || M586TSC || M586 || M486 || MGEODEGX1
321-
---help---
322-
Old PentiumPro multiprocessor systems had errata that could cause
323-
memory operations to violate the x86 ordering standard in rare cases.
324-
Enabling this option will attempt to work around some (but not all)
325-
occurrences of this problem, at the cost of much heavier spinlock and
326-
memory barrier operations.
327-
328-
If unsure, say n here. Even distro kernels should think twice before
329-
enabling this: there are few systems, and an unlikely bug.
330-
331318
config X86_F00F_BUG
332319
def_bool y
333320
depends on M586MMX || M586TSC || M586 || M486

‎arch/x86/entry/vdso/vdso32/vclock_gettime.c‎

Lines changed: 0 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -5,8 +5,6 @@
55
#undef CONFIG_OPTIMIZE_INLINING
66
#endif
77

8-
#undef CONFIG_X86_PPRO_FENCE
9-
108
#ifdefCONFIG_X86_64
119

1210
/*

‎arch/x86/include/asm/barrier.h‎

Lines changed: 0 additions & 30 deletions
Original file line numberDiff line numberDiff line change
@@ -52,11 +52,7 @@ static inline unsigned long array_index_mask_nospec(unsigned long index,
5252
#definebarrier_nospec() alternative_2("", "mfence", X86_FEATURE_MFENCE_RDTSC, \
5353
"lfence", X86_FEATURE_LFENCE_RDTSC)
5454

55-
#ifdefCONFIG_X86_PPRO_FENCE
56-
#definedma_rmb()rmb()
57-
#else
5855
#definedma_rmb()barrier()
59-
#endif
6056
#definedma_wmb()barrier()
6157

6258
#ifdefCONFIG_X86_32
@@ -68,30 +64,6 @@ static inline unsigned long array_index_mask_nospec(unsigned long index,
6864
#define__smp_wmb()barrier()
6965
#define__smp_store_mb(var,value) do { (void)xchg(&var, value); } while (0)
7066

71-
#if defined(CONFIG_X86_PPRO_FENCE)
72-
73-
/*
74-
* For this option x86 doesn't have a strong TSO memory
75-
* model and we should fall back to full barriers.
76-
*/
77-
78-
#define__smp_store_release(p,v)\
79-
do {\
80-
compiletime_assert_atomic_type(*p);\
81-
__smp_mb();\
82-
WRITE_ONCE(*p, v);\
83-
} while (0)
84-
85-
#define__smp_load_acquire(p)\
86-
({\
87-
typeof(*p) ___p1 = READ_ONCE(*p);\
88-
compiletime_assert_atomic_type(*p);\
89-
__smp_mb();\
90-
___p1;\
91-
})
92-
93-
#else/* regular x86 TSO memory ordering */
94-
9567
#define__smp_store_release(p,v)\
9668
do {\
9769
compiletime_assert_atomic_type(*p);\
@@ -107,8 +79,6 @@ do {\
10779
___p1;\
10880
})
10981

110-
#endif
111-
11282
/* Atomic operations are already serializing on x86 */
11383
#define__smp_mb__before_atomic()barrier()
11484
#define__smp_mb__after_atomic()barrier()

‎arch/x86/include/asm/io.h‎

Lines changed: 0 additions & 15 deletions
Original file line numberDiff line numberDiff line change
@@ -232,21 +232,6 @@ extern void set_iounmap_nonlazy(void);
232232
*/
233233
#define__ISA_IO_base ((char __iomem *)(PAGE_OFFSET))
234234

235-
/*
236-
*Cache management
237-
*
238-
*This needed for two cases
239-
*1. Out of order aware processors
240-
*2. Accidentally out of order processors (PPro errata #51)
241-
*/
242-
243-
staticinlinevoidflush_write_buffers(void)
244-
{
245-
#if defined(CONFIG_X86_PPRO_FENCE)
246-
asmvolatile("lock; addl $0,0(%%esp)": : :"memory");
247-
#endif
248-
}
249-
250235
#endif/* __KERNEL__ */
251236

252237
externvoidnative_io_delay(void);

‎arch/x86/kernel/pci-nommu.c‎

Lines changed: 0 additions & 19 deletions
Original file line numberDiff line numberDiff line change
@@ -37,7 +37,6 @@ static dma_addr_t nommu_map_page(struct device *dev, struct page *page,
3737
WARN_ON(size==0);
3838
if (!check_addr("map_single",dev,bus,size))
3939
returnNOMMU_MAPPING_ERROR;
40-
flush_write_buffers();
4140
returnbus;
4241
}
4342

@@ -72,25 +71,9 @@ static int nommu_map_sg(struct device *hwdev, struct scatterlist *sg,
7271
return0;
7372
s->dma_length=s->length;
7473
}
75-
flush_write_buffers();
7674
returnnents;
7775
}
7876

79-
staticvoidnommu_sync_single_for_device(structdevice*dev,
80-
dma_addr_taddr,size_tsize,
81-
enumdma_data_directiondir)
82-
{
83-
flush_write_buffers();
84-
}
85-
86-
87-
staticvoidnommu_sync_sg_for_device(structdevice*dev,
88-
structscatterlist*sg,intnelems,
89-
enumdma_data_directiondir)
90-
{
91-
flush_write_buffers();
92-
}
93-
9477
staticintnommu_mapping_error(structdevice*dev,dma_addr_tdma_addr)
9578
{
9679
returndma_addr==NOMMU_MAPPING_ERROR;
@@ -101,8 +84,6 @@ const struct dma_map_ops nommu_dma_ops = {
10184
.free=dma_generic_free_coherent,
10285
.map_sg=nommu_map_sg,
10386
.map_page=nommu_map_page,
104-
.sync_single_for_device=nommu_sync_single_for_device,
105-
.sync_sg_for_device=nommu_sync_sg_for_device,
10687
.is_phys=1,
10788
.mapping_error=nommu_mapping_error,
10889
.dma_supported=x86_dma_supported,

‎arch/x86/um/asm/barrier.h‎

Lines changed: 0 additions & 4 deletions
Original file line numberDiff line numberDiff line change
@@ -30,11 +30,7 @@
3030

3131
#endif/* CONFIG_X86_32 */
3232

33-
#ifdefCONFIG_X86_PPRO_FENCE
34-
#definedma_rmb()rmb()
35-
#else/* CONFIG_X86_PPRO_FENCE */
3633
#definedma_rmb()barrier()
37-
#endif/* CONFIG_X86_PPRO_FENCE */
3834
#definedma_wmb()barrier()
3935

4036
#include<asm-generic/barrier.h>

0 commit comments

Comments
 (0)
[8]ページ先頭
©2009-2025 Movatter.jp