Introduce a linked list abstraction

For some reason qdl was written with open-coded linked list operations
throughout the implementation, resulting in ugly boiler plate code
sprinkled over the code base.

Integrate the linked list abstraction used in a few other of our
open-source projects to clean up the code.

Signed-off-by: Bjorn Andersson <bjorn.andersson@oss.qualcomm.com>

list.h

@@ -0,0 +1,73 @@
+/* SPDX-License-Identifier: BSD-3-Clause */
+/*
+ * Copyright (c) 2016, Linaro Ltd.
+ */
+#ifndef __LIST_H__
+#define __LIST_H__
+
+#include <stdbool.h>
+#include <stddef.h>
+
+struct list_head {
+	struct list_head *prev;
+	struct list_head *next;
+};
+
+#define LIST_INIT(list) { &(list), &(list) }
+
+static inline void list_init(struct list_head *list)
+{
+	list->prev = list;
+	list->next = list;
+}
+
+static inline bool list_empty(struct list_head *list)
+{
+	return list->next == list;
+}
+
+static inline void list_add(struct list_head *list, struct list_head *item)
+{
+	struct list_head *prev = list->prev;
+
+	item->next = list;
+	item->prev = prev;
+
+	prev->next = item;
+	list->prev = item;
+}
+
+static inline void list_del(struct list_head *item)
+{
+	item->prev->next = item->next;
+	item->next->prev = item->prev;
+}
+
+#define list_for_each(item, list) \
+	for (item = (list)->next; item != list; item = item->next)
+
+#define list_for_each_safe(item, tmp, list) \
+	for (item = (list)->next, tmp = item->next; item != list; item = tmp, tmp = item->next)
+
+#define list_entry(item, type, member) \
+	container_of(item, type, member)
+
+#define list_entry_first(list, type, member) \
+	container_of((list)->next, type, member)
+
+#define list_entry_next(item, member) \
+	container_of((item)->member.next, typeof(*(item)), member)
+
+#define list_for_each_entry(item, list, member) \
+	for (item = list_entry_first(list, typeof(*(item)), member); \
+	     &item->member != list; \
+	     item = list_entry_next(item, member))
+
+#define list_for_each_entry_safe(item, next, list, member) \
+	for (item = list_entry_first(list, typeof(*(item)), member), \
+	     next = list_entry_next(item, member); \
+	     &item->member != list; \
+	     item = next, \
+	     next = list_entry_next(item, member)) \
+
+#endif

patch.c

@@ -13,8 +13,7 @@
 #include "patch.h"
 #include "qdl.h"
 
-static struct patch *patches;
-static struct patch *patches_last;
+static struct list_head patches = LIST_INIT(patches);
 
 int patch_load(const char *patch_file)
 {
@@ -59,13 +58,7 @@ int patch_load(const char *patch_file)
 			continue;
 		}
 
-		if (patches) {
-			patches_last->next = patch;
-			patches_last = patch;
-		} else {
-			patches = patch;
-			patches_last = patch;
-		}
+		list_add(&patches, &patch->node);
 	}
 
 	xmlFreeDoc(doc);
@@ -80,12 +73,12 @@ int patch_execute(struct qdl_device *qdl, int (*apply)(struct qdl_device *qdl, s
 	unsigned int idx = 0;
 	int ret;
 
-	for (patch = patches; patch; patch = patch->next) {
+	list_for_each_entry(patch, &patches, node) {
 		if (!strcmp(patch->filename, "DISK"))
 			count++;
 	}
 
-	for (patch = patches; patch; patch = patch->next) {
+	list_for_each_entry(patch, &patches, node) {
 		if (strcmp(patch->filename, "DISK"))
 			continue;
 
@@ -103,11 +96,10 @@ int patch_execute(struct qdl_device *qdl, int (*apply)(struct qdl_device *qdl, s
 
 void free_patches(void)
 {
-	struct patch *patch = patches;
+	struct patch *patch;
 	struct patch *next;
 
-	for (patch = patches; patch; patch = next) {
-		next = patch->next;
+	list_for_each_entry_safe(patch, next, &patches, node) {
 		free((void *)patch->filename);
 		free((void *)patch->start_sector);
 		free((void *)patch->value);
@@ -115,5 +107,5 @@ void free_patches(void)
 		free(patch);
 	}
 
-	patches = NULL;
+	list_init(&patches);
 }

patch.h

@@ -2,6 +2,8 @@
 #ifndef __PATCH_H__
 #define __PATCH_H__
 
+#include "list.h"
+
 struct qdl_device;
 
 struct patch {
@@ -14,7 +16,7 @@ struct patch {
 	const char *value;
 	const char *what;
 
-	struct patch *next;
+	struct list_head node;
 };
 
 int patch_load(const char *patch_file);

program.c

@@ -20,8 +20,7 @@
 #include "sparse.h"
 #include "gpt.h"
 
-static struct program *programes;
-static struct program *programes_last;
+static struct list_head programs = LIST_INIT(programs);
 
 static int load_erase_tag(xmlNode *node, bool is_nand)
 {
@@ -47,13 +46,7 @@ static int load_erase_tag(xmlNode *node, bool is_nand)
 		return -EINVAL;
 	}
 
-	if (programes) {
-		programes_last->next = program;
-		programes_last = program;
-	} else {
-		programes = program;
-		programes_last = program;
-	}
+	list_add(&programs, &program->node);
 
 	return 0;
 }
@@ -82,14 +75,8 @@ static int program_load_sparse(struct program *program, int fd)
 		if ((off_t)program->sector_size * program->num_sectors ==
 		    lseek(fd, 0, SEEK_END)) {
 			program->sparse = false;
-
-			if (programes) {
-				programes_last->next = program;
-				programes_last = program;
-			} else {
-				programes = program;
-				programes_last = program;
-			}
+			list_add(&programs, &program->node);
+			return 0;
 		}
 
 		ux_err("[PROGRAM] Unable to parse sparse header at %s...failed\n",
@@ -149,14 +136,7 @@ static int program_load_sparse(struct program *program, int fd)
 			else
 				program_sparse->sparse_fill_value = sparse_fill_value;
 
-			program_sparse->next = NULL;
-			if (programes) {
-				programes_last->next = program_sparse;
-				programes_last = program_sparse;
-			} else {
-				programes = program_sparse;
-				programes_last = program_sparse;
-			}
+			list_add(&programs, &program_sparse->node);
 		}
 
 		start_sector = (unsigned int)strtoul(program->start_sector, NULL, 0);
@@ -239,13 +219,7 @@ static int load_program_tag(xmlNode *node, bool is_nand, bool allow_missing, con
 		program->filename = NULL;
 	}
 
-	if (programes) {
-		programes_last->next = program;
-		programes_last = program;
-	} else {
-		programes = program;
-		programes_last = program;
-	}
+	list_add(&programs, &program->node);
 
 	if (fd >= 0)
 		close(fd);
@@ -296,7 +270,7 @@ int program_execute(struct qdl_device *qdl, int (*apply)(struct qdl_device *qdl,
 	int ret;
 	int fd;
 
-	for (program = programes; program; program = program->next) {
+	list_for_each_entry(program, &programs, node) {
 		if (program->is_erase || !program->filename)
 			continue;
 
@@ -321,7 +295,7 @@ int erase_execute(struct qdl_device *qdl, int (*apply)(struct qdl_device *qdl, s
 	struct program *program;
 	int ret;
 
-	for (program = programes; program; program = program->next) {
+	list_for_each_entry(program, &programs, node) {
 		if (!program->is_erase)
 			continue;
 
@@ -338,7 +312,7 @@ static struct program *program_find_partition(const char *partition)
 	struct program *program;
 	const char *label;
 
-	for (program = programes; program; program = program->next) {
+	list_for_each_entry(program, &programs, node) {
 		label = program->label;
 		if (!label)
 			continue;
@@ -412,11 +386,10 @@ int program_is_sec_partition_flashed(void)
 
 void free_programs(void)
 {
-	struct program *program = programes;
+	struct program *program;
 	struct program *next;
 
-	for (program = programes; program; program = next) {
-		next = program->next;
+	list_for_each_entry_safe(program, next, &programs, node) {
 		free((void *)program->filename);
 		free((void *)program->label);
 		free((void *)program->start_sector);
@@ -424,7 +397,7 @@ void free_programs(void)
 		free(program);
 	}
 
-	programes = NULL;
+	list_init(&programs);
 }
 
 int program_cmd_add(const char *address, const char *filename)
@@ -457,13 +430,7 @@ int program_cmd_add(const char *address, const char *filename)
 	program->is_erase = false;
 	program->gpt_partition = gpt_partition;
 
-	if (programes) {
-		programes_last->next = program;
-		programes_last = program;
-	} else {
-		programes = program;
-		programes_last = program;
-	}
+	list_add(&programs, &program->node);
 
 	return 0;
 }
@@ -475,7 +442,7 @@ int program_resolve_gpt_deferrals(struct qdl_device *qdl)
 	char buf[20];
 	int ret;
 
-	for (program = programes; program; program = program->next) {
+	list_for_each_entry(program, &programs, node) {
 		if (!program->gpt_partition)
 			continue;
 

program.h

@@ -5,7 +5,7 @@
 #include <sys/types.h>
 #include <stdbool.h>
 #include <stdint.h>
-#include "qdl.h"
+#include "list.h"
 
 struct program {
 	unsigned int pages_per_block;
@@ -28,9 +28,11 @@ struct program {
 
 	const char *gpt_partition;
 
-	struct program *next;
+	struct list_head node;
 };
 
+struct qdl_device;
+
 int program_load(const char *program_file, bool is_nand, bool allow_missing, const char *incdir);
 int program_execute(struct qdl_device *qdl, int (*apply)(struct qdl_device *qdl, struct program *program, int fd));
 int erase_execute(struct qdl_device *qdl, int (*apply)(struct qdl_device *qdl, struct program *program));

read.c

@@ -11,13 +11,13 @@
 #include <libxml/parser.h>
 #include <libxml/tree.h>
 
+#include "list.h"
 #include "read.h"
 #include "qdl.h"
 #include "oscompat.h"
 #include "gpt.h"
 
-static struct read_op *read_ops;
-static struct read_op *read_ops_last;
+static struct list_head read_ops = LIST_INIT(read_ops);
 
 int read_op_load(const char *read_op_file, const char *incdir)
 {
@@ -67,13 +67,7 @@ int read_op_load(const char *read_op_file, const char *incdir)
 				read_op->filename = strdup(tmp);
 		}
 
-		if (read_ops) {
-			read_ops_last->next = read_op;
-			read_ops_last = read_op;
-		} else {
-			read_ops = read_op;
-			read_ops_last = read_op;
-		}
+		list_add(&read_ops, &read_op->node);
 	}
 
 	xmlFreeDoc(doc);
@@ -87,7 +81,7 @@ int read_op_execute(struct qdl_device *qdl, int (*apply)(struct qdl_device *qdl,
 	int ret;
 	int fd;
 
-	for (read_op = read_ops; read_op; read_op = read_op->next) {
+	list_for_each_entry(read_op, &read_ops, node) {
 		fd = open(read_op->filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, 0644);
 		if (fd < 0) {
 			ux_info("unable to open %s...\n", read_op->filename);
@@ -133,13 +127,7 @@ int read_cmd_add(const char *address, const char *filename)
 	read_op->start_sector = strdup(buf);
 	read_op->gpt_partition = gpt_partition;
 
-	if (read_ops) {
-		read_ops_last->next = read_op;
-		read_ops_last = read_op;
-	} else {
-		read_ops = read_op;
-		read_ops_last = read_op;
-	}
+	list_add(&read_ops, &read_op->node);
 
 	return 0;
 }
@@ -151,7 +139,7 @@ int read_resolve_gpt_deferrals(struct qdl_device *qdl)
 	char buf[20];
 	int ret;
 
-	for (read_op = read_ops; read_op; read_op = read_op->next) {
+	list_for_each_entry(read_op, &read_ops, node) {
 		if (!read_op->gpt_partition)
 			continue;
 

read.h

@@ -4,6 +4,8 @@
 
 #include <stdbool.h>
 
+#include "list.h"
+
 struct qdl_device;
 
 struct read_op {
@@ -13,7 +15,8 @@ struct read_op {
 	unsigned int num_sectors;
 	const char *start_sector;
 	const char *gpt_partition;
-	struct read_op *next;
+
+	struct list_head node;
 };
 
 int read_op_load(const char *read_op_file, const char *incdir);

ufs.c

@@ -15,12 +15,12 @@
 
 #include "ufs.h"
 #include "qdl.h"
+#include "list.h"
 #include "patch.h"
 
 struct ufs_common *ufs_common_p;
 struct ufs_epilogue *ufs_epilogue_p;
-struct ufs_body *ufs_body_p;
-struct ufs_body *ufs_body_last;
+static struct list_head ufs_bodies = LIST_INIT(ufs_bodies);
 
 static const char notice_bconfigdescrlock[] = "\n"
 "Please pay attention that UFS provisioning is irreversible (OTP) operation unless parameter bConfigDescrLock = 0.\n"
@@ -124,6 +124,7 @@ int ufs_load(const char *ufs_file, bool finalize_provisioning)
 	xmlDoc *doc;
 	int retval = 0;
 	struct ufs_body *ufs_body_tmp;
+	struct ufs_body *ufs_body;
 
 	if (ufs_common_p) {
 		ux_err("Only one UFS provisioning XML allowed, \"%s\" ignored\n",
@@ -169,13 +170,7 @@ int ufs_load(const char *ufs_file, bool finalize_provisioning)
 		} else if (xmlGetProp(node, (xmlChar *)"LUNum")) {
 			ufs_body_tmp = ufs_parse_body(node);
 			if (ufs_body_tmp) {
-				if (ufs_body_p) {
-					ufs_body_last->next = ufs_body_tmp;
-					ufs_body_last = ufs_body_tmp;
-				} else {
-					ufs_body_p = ufs_body_tmp;
-					ufs_body_last = ufs_body_tmp;
-				}
+				list_add(&ufs_bodies, &ufs_body_tmp->node);
 			} else {
 				ux_err("invalid UFS body tag found in \"%s\"\n",
 				       ufs_file);
@@ -210,7 +205,7 @@ int ufs_load(const char *ufs_file, bool finalize_provisioning)
 
 	xmlFreeDoc(doc);
 
-	if (!retval && (!ufs_common_p || !ufs_body_p || !ufs_epilogue_p)) {
+	if (!retval && (!ufs_common_p || list_empty(&ufs_bodies) || !ufs_epilogue_p)) {
 		ux_err("incomplete UFS provisioning information in \"%s\"\n", ufs_file);
 		retval = -EINVAL;
 	}
@@ -219,8 +214,8 @@ int ufs_load(const char *ufs_file, bool finalize_provisioning)
 		if (ufs_common_p) {
 			free(ufs_common_p);
 		}
-		if (ufs_body_p) {
-			free(ufs_body_p);
+		list_for_each_entry_safe(ufs_body, ufs_body_tmp, &ufs_bodies, node) {
+			free(ufs_body);
 		}
 		if (ufs_epilogue_p) {
 			free(ufs_epilogue_p);
@@ -260,7 +255,7 @@ int ufs_provisioning_execute(struct qdl_device *qdl,
 	ret = apply_ufs_common(qdl, ufs_common_p);
 	if (ret)
 		return ret;
-	for (body = ufs_body_p; body; body = body->next) {
+	list_for_each_entry(body, &ufs_bodies, node) {
 		ret = apply_ufs_body(qdl, body);
 		if (ret)
 			return ret;
@@ -275,7 +270,7 @@ int ufs_provisioning_execute(struct qdl_device *qdl,
 	ret = apply_ufs_common(qdl, ufs_common_p);
 	if (ret)
 		return ret;
-	for (body = ufs_body_p; body; body = body->next) {
+	list_for_each_entry(body, &ufs_bodies, node) {
 		ret = apply_ufs_body(qdl, body);
 		if (ret)
 			return ret;

ufs.h

@@ -6,6 +6,8 @@
 #define __UFS_H__
 #include <stdbool.h>
 
+#include "list.h"
+
 struct qdl_device;
 
 struct ufs_common {
@@ -37,7 +39,7 @@ struct ufs_body {
 	unsigned int wContextCapabilities;
 	const char	*desc;
 
-	struct		ufs_body *next;
+	struct list_head node;
 };
 
 struct ufs_epilogue {