Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
powerpc/crash: use generic APIs to locate memory hole for kdump
On PowerPC, the memory reserved for the crashkernel can contain components
like RTAS, TCE, OPAL, etc., which should be avoided when loading kexec
segments into crashkernel memory. Due to these special components,
PowerPC has its own set of APIs to locate holes in the crashkernel memory
for loading kexec segments for kdump. However, for loading kexec segments
in the kexec case, PowerPC already uses generic APIs to locate holes.
The previous patch in this series, titled "crash: Let arch decide usable
memory range in reserved area," introduced arch-specific hook to handle
such special regions in the crashkernel area. So, switch PowerPC to use
the generic APIs to locate memory holes for kdump and remove the redundant
PowerPC-specific APIs.
Link: https://lkml.kernel.org/r/20250131113830.925179-5-sourabhjain@linux.ibm.com
Signed-off-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Cc: Baoquan he <bhe@redhat.com>
Cc: Hari Bathini <hbathini@linux.ibm.com>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Mahesh Salgaonkar <mahesh@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
authored by
Sourabh Jain
and committed by
Andrew Morton
6e5250ea
9f0552c9
+13
-252
+4
-2
arch/powerpc/include/asm/kexec.h
+4
-2
arch/powerpc/include/asm/kexec.h
···
94
94
int arch_kimage_file_post_load_cleanup(struct kimage *image);
95
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#define arch_kimage_file_post_load_cleanup arch_kimage_file_post_load_cleanup
96
96
97
-
int arch_kexec_locate_mem_hole(struct kexec_buf *kbuf);
98
-
#define arch_kexec_locate_mem_hole arch_kexec_locate_mem_hole
97
+
int arch_check_excluded_range(struct kimage *image, unsigned long start,
98
+
unsigned long end);
99
+
#define arch_check_excluded_range arch_check_excluded_range
100
+
99
101
100
102
int load_crashdump_segments_ppc64(struct kimage *image,
101
103
struct kexec_buf *kbuf);
+9
-250
arch/powerpc/kexec/file_load_64.c
+9
-250
arch/powerpc/kexec/file_load_64.c
···
49
49
NULL
50
50
};
51
51
52
-
/**
53
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* __locate_mem_hole_top_down - Looks top down for a large enough memory hole
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* in the memory regions between buf_min & buf_max
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* for the buffer. If found, sets kbuf->mem.
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* @kbuf: Buffer contents and memory parameters.
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* @buf_min: Minimum address for the buffer.
58
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* @buf_max: Maximum address for the buffer.
59
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*
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* Returns 0 on success, negative errno on error.
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-
*/
62
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static int __locate_mem_hole_top_down(struct kexec_buf *kbuf,
63
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u64 buf_min, u64 buf_max)
52
+
int arch_check_excluded_range(struct kimage *image, unsigned long start,
53
+
unsigned long end)
64
54
{
65
-
int ret = -EADDRNOTAVAIL;
66
-
phys_addr_t start, end;
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u64 i;
55
+
struct crash_mem *emem;
56
+
int i;
68
57
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for_each_mem_range_rev(i, &start, &end) {
70
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/*
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* memblock uses [start, end) convention while it is
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* [start, end] here. Fix the off-by-one to have the
73
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* same convention.
74
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*/
75
-
end -= 1;
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emem = image->arch.exclude_ranges;
59
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for (i = 0; i < emem->nr_ranges; i++)
60
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if (start < emem->ranges[i].end && end > emem->ranges[i].start)
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return 1;
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-
if (start > buf_max)
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continue;
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/* Memory hole not found */
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if (end < buf_min)
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break;
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-
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/* Adjust memory region based on the given range */
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if (start < buf_min)
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start = buf_min;
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if (end > buf_max)
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end = buf_max;
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-
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start = ALIGN(start, kbuf->buf_align);
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if (start < end && (end - start + 1) >= kbuf->memsz) {
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/* Suitable memory range found. Set kbuf->mem */
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kbuf->mem = ALIGN_DOWN(end - kbuf->memsz + 1,
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kbuf->buf_align);
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ret = 0;
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break;
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}
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}
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return ret;
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}
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-
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/**
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* locate_mem_hole_top_down_ppc64 - Skip special memory regions to find a
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* suitable buffer with top down approach.
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* @kbuf: Buffer contents and memory parameters.
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* @buf_min: Minimum address for the buffer.
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* @buf_max: Maximum address for the buffer.
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* @emem: Exclude memory ranges.
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*
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* Returns 0 on success, negative errno on error.
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*/
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static int locate_mem_hole_top_down_ppc64(struct kexec_buf *kbuf,
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u64 buf_min, u64 buf_max,
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const struct crash_mem *emem)
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{
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int i, ret = 0, err = -EADDRNOTAVAIL;
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u64 start, end, tmin, tmax;
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-
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tmax = buf_max;
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for (i = (emem->nr_ranges - 1); i >= 0; i--) {
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start = emem->ranges[i].start;
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end = emem->ranges[i].end;
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-
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if (start > tmax)
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continue;
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-
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if (end < tmax) {
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tmin = (end < buf_min ? buf_min : end + 1);
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ret = __locate_mem_hole_top_down(kbuf, tmin, tmax);
131
-
if (!ret)
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return 0;
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}
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tmax = start - 1;
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-
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if (tmax < buf_min) {
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ret = err;
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break;
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}
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ret = 0;
142
-
}
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-
144
-
if (!ret) {
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tmin = buf_min;
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ret = __locate_mem_hole_top_down(kbuf, tmin, tmax);
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}
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return ret;
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-
}
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-
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/**
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* __locate_mem_hole_bottom_up - Looks bottom up for a large enough memory hole
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* in the memory regions between buf_min & buf_max
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* for the buffer. If found, sets kbuf->mem.
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* @kbuf: Buffer contents and memory parameters.
156
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* @buf_min: Minimum address for the buffer.
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* @buf_max: Maximum address for the buffer.
158
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*
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* Returns 0 on success, negative errno on error.
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*/
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static int __locate_mem_hole_bottom_up(struct kexec_buf *kbuf,
162
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u64 buf_min, u64 buf_max)
163
-
{
164
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int ret = -EADDRNOTAVAIL;
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phys_addr_t start, end;
166
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u64 i;
167
-
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for_each_mem_range(i, &start, &end) {
169
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/*
170
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* memblock uses [start, end) convention while it is
171
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* [start, end] here. Fix the off-by-one to have the
172
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* same convention.
173
-
*/
174
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end -= 1;
175
-
176
-
if (end < buf_min)
177
-
continue;
178
-
179
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/* Memory hole not found */
180
-
if (start > buf_max)
181
-
break;
182
-
183
-
/* Adjust memory region based on the given range */
184
-
if (start < buf_min)
185
-
start = buf_min;
186
-
if (end > buf_max)
187
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end = buf_max;
188
-
189
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start = ALIGN(start, kbuf->buf_align);
190
-
if (start < end && (end - start + 1) >= kbuf->memsz) {
191
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/* Suitable memory range found. Set kbuf->mem */
192
-
kbuf->mem = start;
193
-
ret = 0;
194
-
break;
195
-
}
196
-
}
197
-
198
-
return ret;
199
-
}
200
-
201
-
/**
202
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* locate_mem_hole_bottom_up_ppc64 - Skip special memory regions to find a
203
-
* suitable buffer with bottom up approach.
204
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* @kbuf: Buffer contents and memory parameters.
205
-
* @buf_min: Minimum address for the buffer.
206
-
* @buf_max: Maximum address for the buffer.
207
-
* @emem: Exclude memory ranges.
208
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*
209
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* Returns 0 on success, negative errno on error.
210
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*/
211
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static int locate_mem_hole_bottom_up_ppc64(struct kexec_buf *kbuf,
212
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u64 buf_min, u64 buf_max,
213
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const struct crash_mem *emem)
214
-
{
215
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int i, ret = 0, err = -EADDRNOTAVAIL;
216
-
u64 start, end, tmin, tmax;
217
-
218
-
tmin = buf_min;
219
-
for (i = 0; i < emem->nr_ranges; i++) {
220
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start = emem->ranges[i].start;
221
-
end = emem->ranges[i].end;
222
-
223
-
if (end < tmin)
224
-
continue;
225
-
226
-
if (start > tmin) {
227
-
tmax = (start > buf_max ? buf_max : start - 1);
228
-
ret = __locate_mem_hole_bottom_up(kbuf, tmin, tmax);
229
-
if (!ret)
230
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return 0;
231
-
}
232
-
233
-
tmin = end + 1;
234
-
235
-
if (tmin > buf_max) {
236
-
ret = err;
237
-
break;
238
-
}
239
-
ret = 0;
240
-
}
241
-
242
-
if (!ret) {
243
-
tmax = buf_max;
244
-
ret = __locate_mem_hole_bottom_up(kbuf, tmin, tmax);
245
-
}
246
-
return ret;
63
+
return 0;
247
64
}
248
65
249
66
#ifdef CONFIG_CRASH_DUMP
···
818
1001
819
1002
out:
820
1003
kfree(umem);
821
-
return ret;
822
-
}
823
-
824
-
/**
825
-
* arch_kexec_locate_mem_hole - Skip special memory regions like rtas, opal,
826
-
* tce-table, reserved-ranges & such (exclude
827
-
* memory ranges) as they can't be used for kexec
828
-
* segment buffer. Sets kbuf->mem when a suitable
829
-
* memory hole is found.
830
-
* @kbuf: Buffer contents and memory parameters.
831
-
*
832
-
* Assumes minimum of PAGE_SIZE alignment for kbuf->memsz & kbuf->buf_align.
833
-
*
834
-
* Returns 0 on success, negative errno on error.
835
-
*/
836
-
int arch_kexec_locate_mem_hole(struct kexec_buf *kbuf)
837
-
{
838
-
struct crash_mem **emem;
839
-
u64 buf_min, buf_max;
840
-
int ret;
841
-
842
-
/* Look up the exclude ranges list while locating the memory hole */
843
-
emem = &(kbuf->image->arch.exclude_ranges);
844
-
if (!(*emem) || ((*emem)->nr_ranges == 0)) {
845
-
pr_warn("No exclude range list. Using the default locate mem hole method\n");
846
-
return kexec_locate_mem_hole(kbuf);
847
-
}
848
-
849
-
buf_min = kbuf->buf_min;
850
-
buf_max = kbuf->buf_max;
851
-
/* Segments for kdump kernel should be within crashkernel region */
852
-
if (IS_ENABLED(CONFIG_CRASH_DUMP) && kbuf->image->type == KEXEC_TYPE_CRASH) {
853
-
buf_min = (buf_min < crashk_res.start ?
854
-
crashk_res.start : buf_min);
855
-
buf_max = (buf_max > crashk_res.end ?
856
-
crashk_res.end : buf_max);
857
-
}
858
-
859
-
if (buf_min > buf_max) {
860
-
pr_err("Invalid buffer min and/or max values\n");
861
-
return -EINVAL;
862
-
}
863
-
864
-
if (kbuf->top_down)
865
-
ret = locate_mem_hole_top_down_ppc64(kbuf, buf_min, buf_max,
866
-
*emem);
867
-
else
868
-
ret = locate_mem_hole_bottom_up_ppc64(kbuf, buf_min, buf_max,
869
-
*emem);
870
-
871
-
/* Add the buffer allocated to the exclude list for the next lookup */
872
-
if (!ret) {
873
-
add_mem_range(emem, kbuf->mem, kbuf->memsz);
874
-
sort_memory_ranges(*emem, true);
875
-
} else {
876
-
pr_err("Failed to locate memory buffer of size %lu\n",
877
-
kbuf->memsz);
878
-
}
879
1004
return ret;
880
1005
}
881
1006