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From:   Siddharth Gupta <sidgup@codeaurora.org>
To:     agross@kernel.org, bjorn.andersson@linaro.org, ohad@wizery.com,
        linux-remoteproc@vger.kernel.org
Cc:     Siddharth Gupta <sidgup@codeaurora.org>,
        linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org, tsoni@codeaurora.org,
        psodagud@codeaurora.org, rishabhb@codeaurora.org,
        linux-doc@vger.kernel.org, Gurbir Arora <gurbaror@codeaurora.org>
Subject: [PATCH v5 2/3] remoteproc: qcom: Add capability to collect minidumps
Date:   Thu, 24 Sep 2020 16:51:27 -0700
Message-Id: <1600991488-17877-3-git-send-email-sidgup@codeaurora.org>
In-Reply-To: <1600991488-17877-1-git-send-email-sidgup@codeaurora.org>
References: <1600991488-17877-1-git-send-email-sidgup@codeaurora.org>
Precedence: bulk

This patch adds support for collecting minidump in the event of remoteproc
crash. Parse the minidump table based on remoteproc's unique minidump-id,
read all memory regions from the remoteproc's minidump table entry and
expose the memory to userspace. The remoteproc platform driver can choose
to collect a full/mini dump by specifying the coredump op.

Signed-off-by: Rishabh Bhatnagar <rishabhb@codeaurora.org>
Signed-off-by: Gurbir Arora <gurbaror@codeaurora.org>
Signed-off-by: Siddharth Gupta <sidgup@codeaurora.org>
---
 drivers/remoteproc/qcom_minidump.h          |  64 +++++++++++++
 drivers/remoteproc/qcom_q6v5_pas.c          | 106 ++++++++++++++++++++-
 drivers/remoteproc/remoteproc_coredump.c    | 138 ++++++++++++++++++++++++++++
 drivers/remoteproc/remoteproc_elf_helpers.h |  27 ++++++
 include/linux/remoteproc.h                  |   1 +
 5 files changed, 334 insertions(+), 2 deletions(-)
 create mode 100644 drivers/remoteproc/qcom_minidump.h

diff --git a/drivers/remoteproc/qcom_minidump.h b/drivers/remoteproc/qcom_minidump.h
new file mode 100644
index 0000000..437e030
--- /dev/null
+++ b/drivers/remoteproc/qcom_minidump.h
@@ -0,0 +1,64 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (c) 2020, The Linux Foundation. All rights reserved.
+ */
+
+#ifndef __QCOM_MINIDUMP_H
+#define __QCOM_MINIDUMP_H
+
+#define MAX_NUM_OF_SS           10
+#define MAX_REGION_NAME_LENGTH  16
+#define SBL_MINIDUMP_SMEM_ID	602
+#define MD_REGION_VALID		('V' << 24 | 'A' << 16 | 'L' << 8 | 'I' << 0)
+#define MD_SS_ENCR_DONE		('D' << 24 | 'O' << 16 | 'N' << 8 | 'E' << 0)
+#define MD_SS_ENABLED		('E' << 24 | 'N' << 16 | 'B' << 8 | 'L' << 0)
+
+/**
+ * md_ss_region - Minidump region
+ * @name		: Name of the region to be dumped
+ * @seq_num:		: Use to differentiate regions with same name.
+ * @md_valid		: This entry to be dumped (if set to 1)
+ * @region_base_address	: Physical address of region to be dumped
+ * @region_size		: Size of the region
+ */
+struct md_ss_region {
+	char	name[MAX_REGION_NAME_LENGTH];
+	u32	seq_num;
+	u32	md_valid;
+	u64	region_base_address;
+	u64	region_size;
+};
+
+/**
+ * md_ss_toc: Subsystem's SMEM Table of content
+ * @md_ss_toc_init : Subsystem toc init status
+ * @md_ss_enable_status : if set to 1, this region would be copied during coredump
+ * @encryption_status: Encryption status for this subsystem
+ * @encryption_required : Decides to encrypt the subsystem regions or not
+ * @ss_region_count : Number of regions added in this subsystem toc
+ * @md_ss_smem_regions_baseptr : regions base pointer of the subsystem
+ */
+struct md_ss_toc {
+	u32			md_ss_toc_init;
+	u32			md_ss_enable_status;
+	u32			encryption_status;
+	u32			encryption_required;
+	u32			ss_region_count;
+	u64			md_ss_smem_regions_baseptr;
+};
+
+/**
+ * md_global_toc: Global Table of Content
+ * @md_toc_init : Global Minidump init status
+ * @md_revision : Minidump revision
+ * @md_enable_status : Minidump enable status
+ * @md_ss_toc : Array of subsystems toc
+ */
+struct md_global_toc {
+	u32			md_toc_init;
+	u32			md_revision;
+	u32			md_enable_status;
+	struct md_ss_toc	md_ss_toc[MAX_NUM_OF_SS];
+};
+
+#endif
diff --git a/drivers/remoteproc/qcom_q6v5_pas.c b/drivers/remoteproc/qcom_q6v5_pas.c
index 3837f23..752c862 100644
--- a/drivers/remoteproc/qcom_q6v5_pas.c
+++ b/drivers/remoteproc/qcom_q6v5_pas.c
@@ -28,11 +28,13 @@
 #include "qcom_pil_info.h"
 #include "qcom_q6v5.h"
 #include "remoteproc_internal.h"
+#include "qcom_minidump.h"
 
 struct adsp_data {
 	int crash_reason_smem;
 	const char *firmware_name;
 	int pas_id;
+	unsigned int minidump_id;
 	bool has_aggre2_clk;
 	bool auto_boot;
 
@@ -63,6 +65,7 @@ struct qcom_adsp {
 	int proxy_pd_count;
 
 	int pas_id;
+	unsigned int minidump_id;
 	int crash_reason_smem;
 	bool has_aggre2_clk;
 	const char *info_name;
@@ -81,6 +84,8 @@ struct qcom_adsp {
 	struct qcom_sysmon *sysmon;
 };
 
+static struct md_global_toc *g_md_toc;
+
 static int adsp_pds_enable(struct qcom_adsp *adsp, struct device **pds,
 			   size_t pd_count)
 {
@@ -116,6 +121,88 @@ static void adsp_pds_disable(struct qcom_adsp *adsp, struct device **pds,
 	}
 }
 
+static void adsp_add_minidump_segments(struct rproc *rproc, struct md_ss_toc *minidump_ss)
+{
+	struct md_ss_region __iomem *region_info;
+	int seg_cnt = 0, i;
+	void __iomem *ptr;
+	dma_addr_t da;
+	size_t size;
+	char *name;
+
+	seg_cnt = minidump_ss->ss_region_count;
+	ptr = ioremap((unsigned long)minidump_ss->md_ss_smem_regions_baseptr,
+		      seg_cnt * sizeof(struct md_ss_region));
+
+	if (!ptr)
+		return;
+
+	region_info = ptr;
+
+	if (!list_empty(&rproc->dump_segments)) {
+		dev_info(&rproc->dev, "dump segment list already populated\n");
+		goto unmap_iomem;
+	}
+
+	for (i = 0; i < seg_cnt; i++) {
+		if (__raw_readl(&region_info->md_valid) == MD_REGION_VALID) {
+			name = kmalloc(MAX_REGION_NAME_LENGTH, GFP_KERNEL);
+			memcpy_fromio(name, region_info->name, sizeof(region_info->name));
+			da = __raw_readq(&region_info->region_base_address);
+			size = __raw_readq(&region_info->region_size);
+			rproc_coredump_add_custom_segment(rproc, da, size, NULL, name);
+		}
+		region_info++;
+	}
+
+unmap_iomem:
+	iounmap(ptr);
+}
+
+static void adsp_dump(struct rproc *rproc)
+{
+	struct qcom_adsp *adsp = (struct qcom_adsp *)rproc->priv;
+	struct md_ss_toc *minidump_ss;
+	size_t size;
+
+	/* Get Global minidump ToC*/
+	if (!g_md_toc)
+		g_md_toc = qcom_smem_get(QCOM_SMEM_HOST_ANY,
+					 SBL_MINIDUMP_SMEM_ID, &size);
+
+	/* check if global table pointer exists and init is set */
+	if (IS_ERR(g_md_toc) || !(g_md_toc->md_toc_init)) {
+		dev_err(&rproc->dev, "SMEM is not initialized.\n");
+		return;
+	}
+
+	/* Get subsystem table of contents using the minidump id */
+	minidump_ss = &g_md_toc->md_ss_toc[adsp->minidump_id];
+
+	/**
+	 * Collect minidump if SS ToC is valid and segment table
+	 * is initialized in memory and encryption status is set.
+	 */
+	if (minidump_ss->md_ss_smem_regions_baseptr == 0 ||
+	    minidump_ss->md_ss_toc_init != 1 ||
+	    minidump_ss->md_ss_enable_status != MD_SS_ENABLED ||
+	    minidump_ss->encryption_status != MD_SS_ENCR_DONE) {
+		dev_err(&rproc->dev, "Minidump not ready!! Aborting\n");
+		return;
+	}
+
+	adsp_add_minidump_segments(rproc, minidump_ss);
+	rproc_minidump(rproc);
+}
+
+static void adsp_priv_cleanup(struct rproc *rproc)
+{
+	struct rproc_dump_segment *segment;
+
+	list_for_each_entry(segment, &rproc->dump_segments, node)
+		kfree(segment->priv);
+}
+
 static int adsp_load(struct rproc *rproc, const struct firmware *fw)
 {
 	struct qcom_adsp *adsp = (struct qcom_adsp *)rproc->priv;
@@ -258,6 +345,15 @@ static const struct rproc_ops adsp_ops = {
 	.panic = adsp_panic,
 };
 
+static const struct rproc_ops adsp_minidump_ops = {
+	.start = adsp_start,
+	.stop = adsp_stop,
+	.da_to_va = adsp_da_to_va,
+	.load = adsp_load,
+	.coredump = adsp_dump,
+	.priv_cleanup = adsp_priv_cleanup,
+};
+
 static int adsp_init_clock(struct qcom_adsp *adsp)
 {
 	int ret;
@@ -398,8 +494,13 @@ static int adsp_probe(struct platform_device *pdev)
 	if (ret < 0 && ret != -EINVAL)
 		return ret;
 
-	rproc = rproc_alloc(&pdev->dev, pdev->name, &adsp_ops,
-			    fw_name, sizeof(*adsp));
+	if (desc->minidump_id)
+		rproc = rproc_alloc(&pdev->dev, pdev->name, &adsp_minidump_ops, fw_name,
+				    sizeof(*adsp));
+	else
+		rproc = rproc_alloc(&pdev->dev, pdev->name, &adsp_ops, fw_name,
+				    sizeof(*adsp));
+
 	if (!rproc) {
 		dev_err(&pdev->dev, "unable to allocate remoteproc\n");
 		return -ENOMEM;
@@ -411,6 +512,7 @@ static int adsp_probe(struct platform_device *pdev)
 	adsp = (struct qcom_adsp *)rproc->priv;
 	adsp->dev = &pdev->dev;
 	adsp->rproc = rproc;
+	adsp->minidump_id = desc->minidump_id;
 	adsp->pas_id = desc->pas_id;
 	adsp->has_aggre2_clk = desc->has_aggre2_clk;
 	adsp->info_name = desc->sysmon_name;
diff --git a/drivers/remoteproc/remoteproc_coredump.c b/drivers/remoteproc/remoteproc_coredump.c
index bb15a29..0495389 100644
--- a/drivers/remoteproc/remoteproc_coredump.c
+++ b/drivers/remoteproc/remoteproc_coredump.c
@@ -13,6 +13,8 @@
 #include "remoteproc_internal.h"
 #include "remoteproc_elf_helpers.h"
 
+#define MAX_STRTBL_SIZE 512
+
 struct rproc_coredump_state {
 	struct rproc *rproc;
 	void *header;
@@ -27,6 +29,9 @@ void rproc_coredump_cleanup(struct rproc *rproc)
 {
 	struct rproc_dump_segment *entry, *tmp;
 
+	if (rproc->ops->priv_cleanup)
+		rproc->ops->priv_cleanup(rproc);
+
 	list_for_each_entry_safe(entry, tmp, &rproc->dump_segments, node) {
 		list_del(&entry->node);
 		kfree(entry);
@@ -323,3 +328,136 @@ void rproc_coredump(struct rproc *rproc)
 	 */
 	wait_for_completion(&dump_state.dump_done);
 }
+
+/**
+ * rproc_minidump() - perform minidump
+ * @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_minidump(struct rproc *rproc)
+{
+	struct rproc_dump_segment *segment;
+	void *shdr;
+	void *ehdr;
+	size_t data_size;
+	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) +
+		    MAX_STRTBL_SIZE;
+	shnum = 2;
+
+	list_for_each_entry(segment, &rproc->dump_segments, node) {
+		data_size += elf_size_of_shdr(class);
+		if (dump_conf == RPROC_COREDUMP_DEFAULT)
+			data_size += segment->size;
+		shnum++;
+	}
+
+	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);
+
+	/* Set the first section header as null 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, MAX_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, MAX_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, set_section_name(str_tbl, ehdr, class));
+	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,
+				     set_section_name(segment->priv, ehdr, class));
+
+		/* No need to copy segments for inline dumps */
+		if (dump_conf == RPROC_COREDUMP_DEFAULT)
+			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_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);
+
+	/* 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);
+
+	list_for_each_entry(segment, &rproc->dump_segments, node)
+		kfree(segment->priv);
+}
+EXPORT_SYMBOL(rproc_minidump);
diff --git a/drivers/remoteproc/remoteproc_elf_helpers.h b/drivers/remoteproc/remoteproc_elf_helpers.h
index 4b6be7b..d83ebca 100644
--- a/drivers/remoteproc/remoteproc_elf_helpers.h
+++ b/drivers/remoteproc/remoteproc_elf_helpers.h
@@ -11,6 +11,7 @@
 #include <linux/elf.h>
 #include <linux/types.h>
 
+#define MAX_NAME_LENGTH 16
 /**
  * fw_elf_get_class - Get elf class
  * @fw: the ELF firmware image
@@ -65,6 +66,7 @@ ELF_GEN_FIELD_GET_SET(hdr, e_type, u16)
 ELF_GEN_FIELD_GET_SET(hdr, e_version, u32)
 ELF_GEN_FIELD_GET_SET(hdr, e_ehsize, u32)
 ELF_GEN_FIELD_GET_SET(hdr, e_phentsize, u16)
+ELF_GEN_FIELD_GET_SET(hdr, e_shentsize, u16)
 
 ELF_GEN_FIELD_GET_SET(phdr, p_paddr, u64)
 ELF_GEN_FIELD_GET_SET(phdr, p_vaddr, u64)
@@ -74,6 +76,9 @@ ELF_GEN_FIELD_GET_SET(phdr, p_type, u32)
 ELF_GEN_FIELD_GET_SET(phdr, p_offset, u64)
 ELF_GEN_FIELD_GET_SET(phdr, p_flags, u32)
 ELF_GEN_FIELD_GET_SET(phdr, p_align, u64)
+ELF_GEN_FIELD_GET_SET(shdr, sh_type, u32)
+ELF_GEN_FIELD_GET_SET(shdr, sh_flags, u32)
+ELF_GEN_FIELD_GET_SET(shdr, sh_entsize, u16)
 
 ELF_GEN_FIELD_GET_SET(shdr, sh_size, u64)
 ELF_GEN_FIELD_GET_SET(shdr, sh_offset, u64)
@@ -93,4 +98,26 @@ ELF_STRUCT_SIZE(shdr)
 ELF_STRUCT_SIZE(phdr)
 ELF_STRUCT_SIZE(hdr)
 
+static inline unsigned int set_section_name(const char *name, void *ehdr,
+					    u8 class)
+{
+	u16 shstrndx = elf_hdr_get_e_shstrndx(class, ehdr);
+	void *shdr;
+	char *strtab;
+	static int strtable_idx = 1;
+	int idx, ret = 0;
+
+	shdr = ehdr + elf_size_of_hdr(class) + shstrndx * elf_size_of_shdr(class);
+	strtab = ehdr + elf_shdr_get_sh_offset(class, shdr);
+	idx = strtable_idx;
+	if (!strtab || !name)
+		return 0;
+
+	ret = idx;
+	idx += strlcpy((strtab + idx), name, MAX_NAME_LENGTH);
+	strtable_idx = idx + 1;
+
+	return ret;
+}
+
 #endif /* REMOTEPROC_ELF_LOADER_H */
diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h
index a489aec..b7a5f93 100644
--- a/include/linux/remoteproc.h
+++ b/include/linux/remoteproc.h
@@ -658,6 +658,7 @@ rproc_of_resm_mem_entry_init(struct device *dev, u32 of_resm_idx, size_t len,
 int rproc_boot(struct rproc *rproc);
 void rproc_shutdown(struct rproc *rproc);
 void rproc_report_crash(struct rproc *rproc, enum rproc_crash_type type);
+void rproc_minidump(struct rproc *rproc);
 int rproc_coredump_add_segment(struct rproc *rproc, dma_addr_t da, size_t size);
 int rproc_coredump_add_custom_segment(struct rproc *rproc,
 				      dma_addr_t da, size_t size,
-- 
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