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authorRishabh Bhatnagar <rishabhb@codeaurora.org>2020-07-17 01:20:34 +0300
committerBjorn Andersson <bjorn.andersson@linaro.org>2020-07-22 00:03:57 +0300
commitc97319881c9116dc7c56dd30115567b4078c4ba6 (patch)
tree3f58d37590ba18bf8f7954a076b51ad40b27408b /drivers/remoteproc
parent76abf9cea6c8215ea45b9359f11f0e30127c544a (diff)
downloadlinux-c97319881c9116dc7c56dd30115567b4078c4ba6.tar.xz
remoteproc: Add inline coredump functionality
The current coredump implementation uses vmalloc area to copy all the segments. But this might put strain on low memory targets as the firmware size sometimes is in tens of MBs. The situation becomes worse if there are multiple remote processors undergoing recovery at the same time. This patch adds inline coredump functionality that avoids extra memory usage. This requires recovery to be halted until data is read by userspace and free function is called. Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org> Reviewed-by: Sibi Sankar <sibis@codeaurora.org> Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org> Signed-off-by: Rishabh Bhatnagar <rishabhb@codeaurora.org> Tested-by: Sibi Sankar <sibis@codeaurora.org> Link: https://lore.kernel.org/r/1594938035-7327-5-git-send-email-rishabhb@codeaurora.org Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Diffstat (limited to 'drivers/remoteproc')
-rw-r--r--drivers/remoteproc/remoteproc_coredump.c156
1 files changed, 138 insertions, 18 deletions
diff --git a/drivers/remoteproc/remoteproc_coredump.c b/drivers/remoteproc/remoteproc_coredump.c
index 390f563ec019..bb15a29038e8 100644
--- a/drivers/remoteproc/remoteproc_coredump.c
+++ b/drivers/remoteproc/remoteproc_coredump.c
@@ -5,6 +5,7 @@
* Copyright (c) 2020, The Linux Foundation. All rights reserved.
*/
+#include <linux/completion.h>
#include <linux/devcoredump.h>
#include <linux/device.h>
#include <linux/kernel.h>
@@ -12,6 +13,12 @@
#include "remoteproc_internal.h"
#include "remoteproc_elf_helpers.h"
+struct rproc_coredump_state {
+ struct rproc *rproc;
+ void *header;
+ struct completion dump_done;
+};
+
/**
* rproc_coredump_cleanup() - clean up dump_segments list
* @rproc: the remote processor handle
@@ -115,12 +122,110 @@ int rproc_coredump_set_elf_info(struct rproc *rproc, u8 class, u16 machine)
}
EXPORT_SYMBOL(rproc_coredump_set_elf_info);
+static void rproc_coredump_free(void *data)
+{
+ struct rproc_coredump_state *dump_state = data;
+
+ vfree(dump_state->header);
+ complete(&dump_state->dump_done);
+}
+
+static void *rproc_coredump_find_segment(loff_t user_offset,
+ struct list_head *segments,
+ size_t *data_left)
+{
+ struct rproc_dump_segment *segment;
+
+ list_for_each_entry(segment, segments, node) {
+ if (user_offset < segment->size) {
+ *data_left = segment->size - user_offset;
+ return segment;
+ }
+ user_offset -= segment->size;
+ }
+
+ *data_left = 0;
+ return NULL;
+}
+
+static void rproc_copy_segment(struct rproc *rproc, void *dest,
+ struct rproc_dump_segment *segment,
+ size_t offset, size_t size)
+{
+ void *ptr;
+
+ if (segment->dump) {
+ segment->dump(rproc, segment, dest, offset, size);
+ } else {
+ ptr = rproc_da_to_va(rproc, segment->da + offset, size);
+ if (!ptr) {
+ dev_err(&rproc->dev,
+ "invalid copy request for segment %pad with offset %zu and size %zu)\n",
+ &segment->da, offset, size);
+ memset(dest, 0xff, size);
+ } else {
+ memcpy(dest, ptr, size);
+ }
+ }
+}
+
+static ssize_t rproc_coredump_read(char *buffer, loff_t offset, size_t count,
+ void *data, size_t header_sz)
+{
+ size_t seg_data, bytes_left = count;
+ ssize_t copy_sz;
+ struct rproc_dump_segment *seg;
+ struct rproc_coredump_state *dump_state = data;
+ struct rproc *rproc = dump_state->rproc;
+ void *elfcore = dump_state->header;
+
+ /* Copy the vmalloc'ed header first. */
+ if (offset < header_sz) {
+ copy_sz = memory_read_from_buffer(buffer, count, &offset,
+ elfcore, header_sz);
+
+ return copy_sz;
+ }
+
+ /*
+ * Find out the segment memory chunk to be copied based on offset.
+ * Keep copying data until count bytes are read.
+ */
+ while (bytes_left) {
+ seg = rproc_coredump_find_segment(offset - header_sz,
+ &rproc->dump_segments,
+ &seg_data);
+ /* EOF check */
+ if (!seg) {
+ dev_info(&rproc->dev, "Ramdump done, %lld bytes read",
+ offset);
+ break;
+ }
+
+ copy_sz = min_t(size_t, bytes_left, seg_data);
+
+ rproc_copy_segment(rproc, buffer, seg, seg->size - seg_data,
+ copy_sz);
+
+ offset += copy_sz;
+ buffer += copy_sz;
+ bytes_left -= copy_sz;
+ }
+
+ return count - bytes_left;
+}
+
/**
* rproc_coredump() - perform coredump
* @rproc: rproc handle
*
* This function will generate an ELF header for the registered segments
- * and create a devcoredump device associated with rproc.
+ * and create a devcoredump device associated with rproc. Based on the
+ * coredump configuration this function will directly copy the segments
+ * from device memory to userspace or copy segments from device memory to
+ * a separate buffer, which can then be read by userspace.
+ * The first approach avoids using extra vmalloc memory. But it will stall
+ * recovery flow until dump is read by userspace.
*/
void rproc_coredump(struct rproc *rproc)
{
@@ -130,11 +235,13 @@ void rproc_coredump(struct rproc *rproc)
size_t data_size;
size_t offset;
void *data;
- void *ptr;
u8 class = rproc->elf_class;
int phnum = 0;
+ struct rproc_coredump_state dump_state;
+ enum rproc_dump_mechanism dump_conf = rproc->dump_conf;
- if (list_empty(&rproc->dump_segments))
+ if (list_empty(&rproc->dump_segments) ||
+ dump_conf == RPROC_COREDUMP_DISABLED)
return;
if (class == ELFCLASSNONE) {
@@ -144,7 +251,14 @@ void rproc_coredump(struct rproc *rproc)
data_size = elf_size_of_hdr(class);
list_for_each_entry(segment, &rproc->dump_segments, node) {
- data_size += elf_size_of_phdr(class) + segment->size;
+ /*
+ * For default configuration buffer includes headers & segments.
+ * For inline dump buffer just includes headers as segments are
+ * directly read from device memory.
+ */
+ data_size += elf_size_of_phdr(class);
+ if (dump_conf == RPROC_COREDUMP_DEFAULT)
+ data_size += segment->size;
phnum++;
}
@@ -183,23 +297,29 @@ void rproc_coredump(struct rproc *rproc)
elf_phdr_set_p_flags(class, phdr, PF_R | PF_W | PF_X);
elf_phdr_set_p_align(class, phdr, 0);
- if (segment->dump) {
- segment->dump(rproc, segment, data + offset, 0, segment->size);
- } else {
- ptr = rproc_da_to_va(rproc, segment->da, segment->size);
- if (!ptr) {
- dev_err(&rproc->dev,
- "invalid coredump segment (%pad, %zu)\n",
- &segment->da, segment->size);
- memset(data + offset, 0xff, segment->size);
- } else {
- memcpy(data + offset, ptr, segment->size);
- }
- }
+ if (dump_conf == RPROC_COREDUMP_DEFAULT)
+ rproc_copy_segment(rproc, data + offset, segment, 0,
+ segment->size);
offset += elf_phdr_get_p_filesz(class, phdr);
phdr += elf_size_of_phdr(class);
}
+ if (dump_conf == RPROC_COREDUMP_DEFAULT) {
+ dev_coredumpv(&rproc->dev, data, data_size, GFP_KERNEL);
+ return;
+ }
+
+ /* Initialize the dump state struct to be used by rproc_coredump_read */
+ dump_state.rproc = rproc;
+ dump_state.header = data;
+ init_completion(&dump_state.dump_done);
+
+ dev_coredumpm(&rproc->dev, NULL, &dump_state, data_size, GFP_KERNEL,
+ rproc_coredump_read, rproc_coredump_free);
- dev_coredumpv(&rproc->dev, data, data_size, GFP_KERNEL);
+ /*
+ * Wait until the dump is read and free is called. Data is freed
+ * by devcoredump framework automatically after 5 minutes.
+ */
+ wait_for_completion(&dump_state.dump_done);
}