1 files changed, 469 insertions, 0 deletions
diff --git a/drivers/remoteproc/remoteproc_coredump.c b/drivers/remoteproc/remoteproc_coredump.c
new file mode 100644
index 000000000..4b093420d
--- /dev/null
+++ b/drivers/remoteproc/remoteproc_coredump.c
@@ -0,0 +1,469 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Coredump functionality for Remoteproc framework.
+ *
+ * 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>
+#include <linux/remoteproc.h>
+#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
+ */
+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_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_add_custom_segment() - add custom coredump segment
+ * @rproc:	handle of a remote processor
+ * @da:		device address
+ * @size:	size of segment
+ * @dumpfn:	custom dump function called for each segment during coredump
+ * @priv:	private data
+ *
+ * Add device memory to the list of segments to be included in the coredump
+ * and associate the segment with the given custom dump function and private
+ * data.
+ *
+ * Return: 0 on success, negative errno on error.
+ */
+int rproc_coredump_add_custom_segment(struct rproc *rproc,
+				      dma_addr_t da, size_t size,
+				      void (*dumpfn)(struct rproc *rproc,
+						     struct rproc_dump_segment *segment,
+						     void *dest, size_t offset,
+						     size_t size),
+				      void *priv)
+{
+	struct rproc_dump_segment *segment;
+
+	segment = kzalloc(sizeof(*segment), GFP_KERNEL);
+	if (!segment)
+		return -ENOMEM;
+
+	segment->da = da;
+	segment->size = size;
+	segment->priv = priv;
+	segment->dump = dumpfn;
+
+	list_add_tail(&segment->node, &rproc->dump_segments);
+
+	return 0;
+}
+EXPORT_SYMBOL(rproc_coredump_add_custom_segment);
+
+/**
+ * rproc_coredump_set_elf_info() - set coredump elf information
+ * @rproc:	handle of a remote processor
+ * @class:	elf class for coredump elf file
+ * @machine:	elf machine for coredump elf file
+ *
+ * Set elf information which will be used for coredump elf file.
+ *
+ * Return: 0 on success, negative errno on error.
+ */
+int rproc_coredump_set_elf_info(struct rproc *rproc, u8 class, u16 machine)
+{
+	if (class != ELFCLASS64 && class != ELFCLASS32)
+		return -EINVAL;
+
+	rproc->elf_class = class;
+	rproc->elf_machine = machine;
+
+	return 0;
+}
+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)
+{
+	bool is_iomem = false;
+	void *ptr;
+
+	if (segment->dump) {
+		segment->dump(rproc, segment, dest, offset, size);
+	} else {
+		ptr = rproc_da_to_va(rproc, segment->da + offset, size, &is_iomem);
+		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 {
+			if (is_iomem)
+				memcpy_fromio(dest, (void const __iomem *)ptr, 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. 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)
+{
+	struct rproc_dump_segment *segment;
+	void *phdr;
+	void *ehdr;
+	size_t data_size;
+	size_t offset;
+	void *data;
+	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) ||
+	    dump_conf == RPROC_COREDUMP_DISABLED)
+		return;
+
+	if (class == ELFCLASSNONE) {
+		dev_err(&rproc->dev, "Elf class is not set\n");
+		return;
+	}
+
+	data_size = elf_size_of_hdr(class);
+	list_for_each_entry(segment, &rproc->dump_segments, node) {
+		/*
+		 * 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_ENABLED)
+			data_size += segment->size;
+
+		phnum++;
+	}
+
+	data = vmalloc(data_size);
+	if (!data)
+		return;
+
+	ehdr = data;
+
+	memset(ehdr, 0, elf_size_of_hdr(class));
+	/* e_ident field is common for both elf32 and elf64 */
+	elf_hdr_init_ident(ehdr, class);
+
+	elf_hdr_set_e_type(class, ehdr, ET_CORE);
+	elf_hdr_set_e_machine(class, ehdr, rproc->elf_machine);
+	elf_hdr_set_e_version(class, ehdr, EV_CURRENT);
+	elf_hdr_set_e_entry(class, ehdr, rproc->bootaddr);
+	elf_hdr_set_e_phoff(class, ehdr, elf_size_of_hdr(class));
+	elf_hdr_set_e_ehsize(class, ehdr, elf_size_of_hdr(class));
+	elf_hdr_set_e_phentsize(class, ehdr, elf_size_of_phdr(class));
+	elf_hdr_set_e_phnum(class, ehdr, phnum);
+
+	phdr = data + elf_hdr_get_e_phoff(class, ehdr);
+	offset = elf_hdr_get_e_phoff(class, ehdr);
+	offset += elf_size_of_phdr(class) * elf_hdr_get_e_phnum(class, ehdr);
+
+	list_for_each_entry(segment, &rproc->dump_segments, node) {
+		memset(phdr, 0, elf_size_of_phdr(class));
+		elf_phdr_set_p_type(class, phdr, PT_LOAD);
+		elf_phdr_set_p_offset(class, phdr, offset);
+		elf_phdr_set_p_vaddr(class, phdr, segment->da);
+		elf_phdr_set_p_paddr(class, phdr, segment->da);
+		elf_phdr_set_p_filesz(class, phdr, segment->size);
+		elf_phdr_set_p_memsz(class, phdr, segment->size);
+		elf_phdr_set_p_flags(class, phdr, PF_R | PF_W | PF_X);
+		elf_phdr_set_p_align(class, phdr, 0);
+
+		if (dump_conf == RPROC_COREDUMP_ENABLED)
+			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_ENABLED) {
+		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);
+
+	/*
+	 * 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);
+}
+
+/**
+ * rproc_coredump_using_sections() - perform coredump using section headers
+ * @rproc:	rproc handle
+ *
+ * This function will generate an ELF header for the registered sections of
+ * segments 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_using_sections(struct rproc *rproc)
+{
+	struct rproc_dump_segment *segment;
+	void *shdr;
+	void *ehdr;
+	size_t data_size;
+	size_t strtbl_size = 0;
+	size_t strtbl_index = 1;
+	size_t offset;
+	void *data;
+	u8 class = rproc->elf_class;
+	int shnum;
+	struct rproc_coredump_state dump_state;
+	unsigned int dump_conf = rproc->dump_conf;
+	char *str_tbl = "STR_TBL";
+
+	if (list_empty(&rproc->dump_segments) ||
+	    dump_conf == RPROC_COREDUMP_DISABLED)
+		return;
+
+	if (class == ELFCLASSNONE) {
+		dev_err(&rproc->dev, "Elf class is not set\n");
+		return;
+	}
+
+	/*
+	 * We allocate two extra section headers. The first one is null.
+	 * Second section header is for the string table. Also space is
+	 * allocated for string table.
+	 */
+	data_size = elf_size_of_hdr(class) + 2 * elf_size_of_shdr(class);
+	shnum = 2;
+
+	/* the extra byte is for the null character at index 0 */
+	strtbl_size += strlen(str_tbl) + 2;
+
+	list_for_each_entry(segment, &rproc->dump_segments, node) {
+		data_size += elf_size_of_shdr(class);
+		strtbl_size += strlen(segment->priv) + 1;
+		if (dump_conf == RPROC_COREDUMP_ENABLED)
+			data_size += segment->size;
+		shnum++;
+	}
+
+	data_size += strtbl_size;
+
+	data = vmalloc(data_size);
+	if (!data)
+		return;
+
+	ehdr = data;
+	memset(ehdr, 0, elf_size_of_hdr(class));
+	/* e_ident field is common for both elf32 and elf64 */
+	elf_hdr_init_ident(ehdr, class);
+
+	elf_hdr_set_e_type(class, ehdr, ET_CORE);
+	elf_hdr_set_e_machine(class, ehdr, rproc->elf_machine);
+	elf_hdr_set_e_version(class, ehdr, EV_CURRENT);
+	elf_hdr_set_e_entry(class, ehdr, rproc->bootaddr);
+	elf_hdr_set_e_shoff(class, ehdr, elf_size_of_hdr(class));
+	elf_hdr_set_e_ehsize(class, ehdr, elf_size_of_hdr(class));
+	elf_hdr_set_e_shentsize(class, ehdr, elf_size_of_shdr(class));
+	elf_hdr_set_e_shnum(class, ehdr, shnum);
+	elf_hdr_set_e_shstrndx(class, ehdr, 1);
+
+	/*
+	 * The zeroth index of the section header is reserved and is rarely used.
+	 * Set the section header as null (SHN_UNDEF) and move to the next one.
+	 */
+	shdr = data + elf_hdr_get_e_shoff(class, ehdr);
+	memset(shdr, 0, elf_size_of_shdr(class));
+	shdr += elf_size_of_shdr(class);
+
+	/* Initialize the string table. */
+	offset = elf_hdr_get_e_shoff(class, ehdr) +
+		 elf_size_of_shdr(class) * elf_hdr_get_e_shnum(class, ehdr);
+	memset(data + offset, 0, strtbl_size);
+
+	/* Fill in the string table section header. */
+	memset(shdr, 0, elf_size_of_shdr(class));
+	elf_shdr_set_sh_type(class, shdr, SHT_STRTAB);
+	elf_shdr_set_sh_offset(class, shdr, offset);
+	elf_shdr_set_sh_size(class, shdr, strtbl_size);
+	elf_shdr_set_sh_entsize(class, shdr, 0);
+	elf_shdr_set_sh_flags(class, shdr, 0);
+	elf_shdr_set_sh_name(class, shdr, elf_strtbl_add(str_tbl, ehdr, class, &strtbl_index));
+	offset += elf_shdr_get_sh_size(class, shdr);
+	shdr += elf_size_of_shdr(class);
+
+	list_for_each_entry(segment, &rproc->dump_segments, node) {
+		memset(shdr, 0, elf_size_of_shdr(class));
+		elf_shdr_set_sh_type(class, shdr, SHT_PROGBITS);
+		elf_shdr_set_sh_offset(class, shdr, offset);
+		elf_shdr_set_sh_addr(class, shdr, segment->da);
+		elf_shdr_set_sh_size(class, shdr, segment->size);
+		elf_shdr_set_sh_entsize(class, shdr, 0);
+		elf_shdr_set_sh_flags(class, shdr, SHF_WRITE);
+		elf_shdr_set_sh_name(class, shdr,
+				     elf_strtbl_add(segment->priv, ehdr, class, &strtbl_index));
+
+		/* No need to copy segments for inline dumps */
+		if (dump_conf == RPROC_COREDUMP_ENABLED)
+			rproc_copy_segment(rproc, data + offset, segment, 0,
+					   segment->size);
+		offset += elf_shdr_get_sh_size(class, shdr);
+		shdr += elf_size_of_shdr(class);
+	}
+
+	if (dump_conf == RPROC_COREDUMP_ENABLED) {
+		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);
+
+	/* 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);
+}
+EXPORT_SYMBOL(rproc_coredump_using_sections);