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authorSarangdhar Joshi <spjoshi@codeaurora.org>2018-01-06 03:04:17 +0300
committerBjorn Andersson <bjorn.andersson@linaro.org>2018-02-12 22:05:29 +0300
commit2666ca9197e3d352f43b02d7dfb7c6dd72e7c614 (patch)
treeb9c60aed35f13ff5c2fb519bf31eec2ed5d9c644 /drivers/remoteproc
parent2d02d158047643060b7d6e0829fcc81518ce663d (diff)
downloadlinux-2666ca9197e3d352f43b02d7dfb7c6dd72e7c614.tar.xz
remoteproc: Add remote processor coredump support
As the remoteproc framework restarts the remote processor after a fatal event, it's useful to be able to acquire a coredump of the remote processor's state, for post mortem debugging. This patch introduces a mechanism for extracting the memory contents after the remote has stopped and before the restart sequence has begun in the recovery path. The remoteproc framework builds the core dump in memory and use devcoredump to expose this to user space. Signed-off-by: Sarangdhar Joshi <spjoshi@codeaurora.org> [bjorn: Use vmalloc instead of composing the ELF on the fly] Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Diffstat (limited to 'drivers/remoteproc')
-rw-r--r--drivers/remoteproc/Kconfig1
-rw-r--r--drivers/remoteproc/remoteproc_core.c128
2 files changed, 129 insertions, 0 deletions
diff --git a/drivers/remoteproc/Kconfig b/drivers/remoteproc/Kconfig
index b609e1d3654b..3e4bca77188d 100644
--- a/drivers/remoteproc/Kconfig
+++ b/drivers/remoteproc/Kconfig
@@ -6,6 +6,7 @@ config REMOTEPROC
select CRC32
select FW_LOADER
select VIRTIO
+ select WANT_DEV_COREDUMP
help
Support for remote processors (such as DSP coprocessors). These
are mainly used on embedded systems.
diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
index 4170dfbd93bd..5af7547b9d8d 100644
--- a/drivers/remoteproc/remoteproc_core.c
+++ b/drivers/remoteproc/remoteproc_core.c
@@ -33,6 +33,7 @@
#include <linux/firmware.h>
#include <linux/string.h>
#include <linux/debugfs.h>
+#include <linux/devcoredump.h>
#include <linux/remoteproc.h>
#include <linux/iommu.h>
#include <linux/idr.h>
@@ -802,6 +803,20 @@ static void rproc_remove_subdevices(struct rproc *rproc)
}
/**
+ * rproc_coredump_cleanup() - clean up dump_segments list
+ * @rproc: the remote processor handle
+ */
+static void rproc_coredump_cleanup(struct rproc *rproc)
+{
+ struct rproc_dump_segment *entry, *tmp;
+
+ list_for_each_entry_safe(entry, tmp, &rproc->dump_segments, node) {
+ list_del(&entry->node);
+ kfree(entry);
+ }
+}
+
+/**
* rproc_resource_cleanup() - clean up and free all acquired resources
* @rproc: rproc handle
*
@@ -848,6 +863,8 @@ static void rproc_resource_cleanup(struct rproc *rproc)
/* clean up remote vdev entries */
list_for_each_entry_safe(rvdev, rvtmp, &rproc->rvdevs, node)
kref_put(&rvdev->refcount, rproc_vdev_release);
+
+ rproc_coredump_cleanup(rproc);
}
static int rproc_start(struct rproc *rproc, const struct firmware *fw)
@@ -1018,6 +1035,113 @@ static int rproc_stop(struct rproc *rproc)
}
/**
+ * rproc_coredump_add_segment() - add segment of device memory to coredump
+ * @rproc: handle of a remote processor
+ * @da: device address
+ * @size: size of segment
+ *
+ * Add device memory to the list of segments to be included in a coredump for
+ * the remoteproc.
+ *
+ * Return: 0 on success, negative errno on error.
+ */
+int rproc_coredump_add_segment(struct rproc *rproc, dma_addr_t da, size_t size)
+{
+ struct rproc_dump_segment *segment;
+
+ segment = kzalloc(sizeof(*segment), GFP_KERNEL);
+ if (!segment)
+ return -ENOMEM;
+
+ segment->da = da;
+ segment->size = size;
+
+ list_add_tail(&segment->node, &rproc->dump_segments);
+
+ return 0;
+}
+EXPORT_SYMBOL(rproc_coredump_add_segment);
+
+/**
+ * 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.
+ */
+static void rproc_coredump(struct rproc *rproc)
+{
+ struct rproc_dump_segment *segment;
+ struct elf32_phdr *phdr;
+ struct elf32_hdr *ehdr;
+ size_t data_size;
+ size_t offset;
+ void *data;
+ void *ptr;
+ int phnum = 0;
+
+ if (list_empty(&rproc->dump_segments))
+ return;
+
+ data_size = sizeof(*ehdr);
+ list_for_each_entry(segment, &rproc->dump_segments, node) {
+ data_size += sizeof(*phdr) + segment->size;
+
+ phnum++;
+ }
+
+ data = vmalloc(data_size);
+ if (!data)
+ return;
+
+ ehdr = data;
+
+ memset(ehdr, 0, sizeof(*ehdr));
+ memcpy(ehdr->e_ident, ELFMAG, SELFMAG);
+ ehdr->e_ident[EI_CLASS] = ELFCLASS32;
+ ehdr->e_ident[EI_DATA] = ELFDATA2LSB;
+ ehdr->e_ident[EI_VERSION] = EV_CURRENT;
+ ehdr->e_ident[EI_OSABI] = ELFOSABI_NONE;
+ ehdr->e_type = ET_CORE;
+ ehdr->e_machine = EM_NONE;
+ ehdr->e_version = EV_CURRENT;
+ ehdr->e_entry = rproc->bootaddr;
+ ehdr->e_phoff = sizeof(*ehdr);
+ ehdr->e_ehsize = sizeof(*ehdr);
+ ehdr->e_phentsize = sizeof(*phdr);
+ ehdr->e_phnum = phnum;
+
+ phdr = data + ehdr->e_phoff;
+ offset = ehdr->e_phoff + sizeof(*phdr) * ehdr->e_phnum;
+ list_for_each_entry(segment, &rproc->dump_segments, node) {
+ memset(phdr, 0, sizeof(*phdr));
+ phdr->p_type = PT_LOAD;
+ phdr->p_offset = offset;
+ phdr->p_vaddr = segment->da;
+ phdr->p_paddr = segment->da;
+ phdr->p_filesz = segment->size;
+ phdr->p_memsz = segment->size;
+ phdr->p_flags = PF_R | PF_W | PF_X;
+ phdr->p_align = 0;
+
+ 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);
+ }
+
+ offset += phdr->p_filesz;
+ phdr++;
+ }
+
+ dev_coredumpv(&rproc->dev, data, data_size, GFP_KERNEL);
+}
+
+/**
* rproc_trigger_recovery() - recover a remoteproc
* @rproc: the remote processor
*
@@ -1043,6 +1167,9 @@ int rproc_trigger_recovery(struct rproc *rproc)
if (ret)
goto unlock_mutex;
+ /* generate coredump */
+ rproc_coredump(rproc);
+
/* load firmware */
ret = request_firmware(&firmware_p, rproc->firmware, dev);
if (ret < 0) {
@@ -1443,6 +1570,7 @@ struct rproc *rproc_alloc(struct device *dev, const char *name,
INIT_LIST_HEAD(&rproc->traces);
INIT_LIST_HEAD(&rproc->rvdevs);
INIT_LIST_HEAD(&rproc->subdevs);
+ INIT_LIST_HEAD(&rproc->dump_segments);
INIT_WORK(&rproc->crash_handler, rproc_crash_handler_work);