Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
Merge tag 'x86_misc_for_7.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull misc x86 updates from Dave Hansen:
"The usual smattering of x86/misc changes.
The IPv6 patch in here surprised me in a couple of ways. First, the
function it inlines is able to eat a lot more CPU time than I would
have expected. Second, the inlining does not seem to bloat the kernel,
at least in the configs folks have tested.
- Inline x86-specific IPv6 checksum helper
- Update IOMMU docs to use stable identifiers
- Print unhashed pointers on fatal stack overflows"
* tag 'x86_misc_for_7.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/traps: Print unhashed pointers on stack overflow
Documentation/x86: Update IOMMU spec references to use stable identifiers
x86/lib: Inline csum_ipv6_magic()
+39
-39
+4
-3
Documentation/arch/x86/iommu.rst
+4
-3
Documentation/arch/x86/iommu.rst
···
2
2
x86 IOMMU Support
3
3
=================
4
4
5
-
The architecture specs can be obtained from the below locations.
5
+
The architecture specs can be obtained from the vendor websites.
6
+
Search for the following documents to obtain the latest versions:
6
7
7
-
- Intel: http://www.intel.com/content/dam/www/public/us/en/documents/product-specifications/vt-directed-io-spec.pdf
8
-
- AMD: https://www.amd.com/content/dam/amd/en/documents/processor-tech-docs/specifications/48882_3_07_PUB.pdf
8
+
- Intel: Intel Virtualization Technology for Directed I/O Architecture Specification (ID: D51397)
9
+
- AMD: AMD I/O Virtualization Technology (IOMMU) Specification (ID: 48882)
9
10
10
11
This guide gives a quick cheat sheet for some basic understanding.
11
12
+34
-13
arch/x86/include/asm/checksum_64.h
+34
-13
arch/x86/include/asm/checksum_64.h
···
9
9
*/
10
10
11
11
#include <linux/compiler.h>
12
+
#include <linux/in6.h>
12
13
#include <asm/byteorder.h>
13
14
14
15
/**
···
146
145
*/
147
146
extern __sum16 ip_compute_csum(const void *buff, int len);
148
147
148
+
static inline unsigned add32_with_carry(unsigned a, unsigned b)
149
+
{
150
+
asm("addl %2,%0\n\t"
151
+
"adcl $0,%0"
152
+
: "=r" (a)
153
+
: "0" (a), "rm" (b));
154
+
return a;
155
+
}
156
+
157
+
#define _HAVE_ARCH_IPV6_CSUM 1
158
+
149
159
/**
150
160
* csum_ipv6_magic - Compute checksum of an IPv6 pseudo header.
151
161
* @saddr: source address
···
170
158
* Returns the unfolded 32bit checksum.
171
159
*/
172
160
173
-
struct in6_addr;
174
-
175
-
#define _HAVE_ARCH_IPV6_CSUM 1
176
-
extern __sum16
177
-
csum_ipv6_magic(const struct in6_addr *saddr, const struct in6_addr *daddr,
178
-
__u32 len, __u8 proto, __wsum sum);
179
-
180
-
static inline unsigned add32_with_carry(unsigned a, unsigned b)
161
+
static inline __sum16 csum_ipv6_magic(
162
+
const struct in6_addr *_saddr, const struct in6_addr *_daddr,
163
+
__u32 len, __u8 proto, __wsum sum)
181
164
{
182
-
asm("addl %2,%0\n\t"
183
-
"adcl $0,%0"
184
-
: "=r" (a)
185
-
: "0" (a), "rm" (b));
186
-
return a;
165
+
const unsigned long *saddr = (const unsigned long *)_saddr;
166
+
const unsigned long *daddr = (const unsigned long *)_daddr;
167
+
__u64 sum64;
168
+
169
+
sum64 = (__force __u64)htonl(len) + (__force __u64)htons(proto) +
170
+
(__force __u64)sum;
171
+
172
+
asm(" addq %1,%[sum64]\n"
173
+
" adcq %2,%[sum64]\n"
174
+
" adcq %3,%[sum64]\n"
175
+
" adcq %4,%[sum64]\n"
176
+
" adcq $0,%[sum64]\n"
177
+
178
+
: [sum64] "+r" (sum64)
179
+
: "m" (saddr[0]), "m" (saddr[1]),
180
+
"m" (daddr[0]), "m" (daddr[1]));
181
+
182
+
return csum_fold(
183
+
(__force __wsum)add32_with_carry(sum64 & 0xffffffff, sum64>>32));
187
184
}
188
185
189
186
#define HAVE_ARCH_CSUM_ADD
+1
-1
arch/x86/kernel/traps.c
+1
-1
arch/x86/kernel/traps.c
···
549
549
{
550
550
const char *name = stack_type_name(info->type);
551
551
552
-
printk(KERN_EMERG "BUG: %s stack guard page was hit at %p (stack is %p..%p)\n",
552
+
printk(KERN_EMERG "BUG: %s stack guard page was hit at %px (stack is %px..%px)\n",
553
553
name, (void *)fault_address, info->begin, info->end);
554
554
555
555
die("stack guard page", regs, 0);
-22
arch/x86/lib/csum-wrappers_64.c
-22
arch/x86/lib/csum-wrappers_64.c
···
68
68
}
69
69
EXPORT_SYMBOL(csum_partial_copy_nocheck);
70
70
71
-
__sum16 csum_ipv6_magic(const struct in6_addr *saddr,
72
-
const struct in6_addr *daddr,
73
-
__u32 len, __u8 proto, __wsum sum)
74
-
{
75
-
__u64 rest, sum64;
76
-
77
-
rest = (__force __u64)htonl(len) + (__force __u64)htons(proto) +
78
-
(__force __u64)sum;
79
-
80
-
asm(" addq (%[saddr]),%[sum]\n"
81
-
" adcq 8(%[saddr]),%[sum]\n"
82
-
" adcq (%[daddr]),%[sum]\n"
83
-
" adcq 8(%[daddr]),%[sum]\n"
84
-
" adcq $0,%[sum]\n"
85
-
86
-
: [sum] "=r" (sum64)
87
-
: "[sum]" (rest), [saddr] "r" (saddr), [daddr] "r" (daddr));
88
-
89
-
return csum_fold(
90
-
(__force __wsum)add32_with_carry(sum64 & 0xffffffff, sum64>>32));
91
-
}
92
-
EXPORT_SYMBOL(csum_ipv6_magic);