[RFC PATCH v2 4/5] tools/power/acpi: Add userspace AML interface support

From: Lv Zheng
Date: Fri Nov 06 2015 - 01:47:32 EST


This patch adds a userspace tool to access Linux kernel AML debugger
interface.

Tow modes are supported by this tool:
1. Interactive: Users are able to launch a debugging shell to talk with
in-kernel AML debugger.
Note that it's user duty to ensure kernel runtime integrity by using
this debugging tool:
A. Some control methods evaluated by the users may result in kernel
panics if those control methods shouldn't be evaluated by the OSPMs
according to the current BIOS/OS configurations.
B. Currently if a single stepping evaluation couldn't run to an end,
then the synchronization primitives acquired by the evaluation may
block normal OSPM control method evaluations.
2. Batch: Users are able to execute debugger commands in a script.
Note that in addition to the above duties, it's user duty to ensure
script runtime integrity by using this debugging tool in this mode:
C. Currently only those commands that are not used for single stepping
are suitable to be used in this mode.
D. If the execution of the command may cause a failure that could result
in an endless kernel execution, the execution of the script may also
get blocked.
To exit the utility, currently "exit/quit" commands are recommended, but
ctrl-C" can also be used.

Signed-off-by: Lv Zheng <lv.zheng@xxxxxxxxx>
---
tools/power/acpi/Makefile | 16 +-
tools/power/acpi/tools/acpidbg/Makefile | 27 ++
tools/power/acpi/tools/acpidbg/acpidbg.c | 438 ++++++++++++++++++++++++++++++
3 files changed, 473 insertions(+), 8 deletions(-)
create mode 100644 tools/power/acpi/tools/acpidbg/Makefile
create mode 100644 tools/power/acpi/tools/acpidbg/acpidbg.c

diff --git a/tools/power/acpi/Makefile b/tools/power/acpi/Makefile
index e882c83..a8bf908 100644
--- a/tools/power/acpi/Makefile
+++ b/tools/power/acpi/Makefile
@@ -10,18 +10,18 @@

include ../../scripts/Makefile.include

-all: acpidump ec
-clean: acpidump_clean ec_clean
-install: acpidump_install ec_install
-uninstall: acpidump_uninstall ec_uninstall
+all: acpidbg acpidump ec
+clean: acpidbg_clean acpidump_clean ec_clean
+install: acpidbg_install acpidump_install ec_install
+uninstall: acpidbg_uninstall acpidump_uninstall ec_uninstall

-acpidump ec: FORCE
+acpidbg acpidump ec: FORCE
$(call descend,tools/$@,all)
-acpidump_clean ec_clean:
+acpidbg_clean acpidump_clean ec_clean:
$(call descend,tools/$(@:_clean=),clean)
-acpidump_install ec_install:
+acpidbg_install acpidump_install ec_install:
$(call descend,tools/$(@:_install=),install)
-acpidump_uninstall ec_uninstall:
+acpidbg_uninstall acpidump_uninstall ec_uninstall:
$(call descend,tools/$(@:_uninstall=),uninstall)

.PHONY: FORCE
diff --git a/tools/power/acpi/tools/acpidbg/Makefile b/tools/power/acpi/tools/acpidbg/Makefile
new file mode 100644
index 0000000..352df4b
--- /dev/null
+++ b/tools/power/acpi/tools/acpidbg/Makefile
@@ -0,0 +1,27 @@
+# tools/power/acpi/tools/acpidbg/Makefile - ACPI tool Makefile
+#
+# Copyright (c) 2015, Intel Corporation
+# Author: Lv Zheng <lv.zheng@xxxxxxxxx>
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; version 2
+# of the License.
+
+include ../../Makefile.config
+
+TOOL = acpidbg
+vpath %.c \
+ ../../../../../drivers/acpi/acpica\
+ ../../common\
+ ../../os_specific/service_layers\
+ .
+CFLAGS += -DACPI_APPLICATION -DACPI_SINGLE_THREAD -DACPI_DEBUGGER\
+ -I.\
+ -I../../../../../drivers/acpi/acpica\
+ -I../../../../../include
+LDFLAGS += -lpthread
+TOOL_OBJS = \
+ acpidbg.o
+
+include ../../Makefile.rules
diff --git a/tools/power/acpi/tools/acpidbg/acpidbg.c b/tools/power/acpi/tools/acpidbg/acpidbg.c
new file mode 100644
index 0000000..e4e8316
--- /dev/null
+++ b/tools/power/acpi/tools/acpidbg/acpidbg.c
@@ -0,0 +1,438 @@
+/*
+ * ACPI AML interfacing userspace utility
+ *
+ * Copyright (C) 2015, Intel Corporation
+ * Authors: Lv Zheng <lv.zheng@xxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <acpi/acpi.h>
+
+/* Headers not included by include/acpi/platform/aclinux.h */
+#include <stdbool.h>
+#include <fcntl.h>
+#include <assert.h>
+#include <linux/circ_buf.h>
+
+#define ACPI_AML_FILE "/sys/kernel/debug/acpi/acpidbg"
+#define ACPI_AML_SEC_TICK 1
+#define ACPI_AML_USEC_PEEK 200
+#define ACPI_AML_BUF_SIZE 4096
+
+#define ACPI_AML_BATCH_WRITE_CMD 0x00 /* Write command to kernel */
+#define ACPI_AML_BATCH_READ_LOG 0x01 /* Read log from kernel */
+#define ACPI_AML_BATCH_WRITE_LOG 0x02 /* Write log to console */
+
+#define ACPI_AML_LOG_START 0x00
+#define ACPI_AML_PROMPT_START 0x01
+#define ACPI_AML_PROMPT_STOP 0x02
+#define ACPI_AML_LOG_STOP 0x03
+#define ACPI_AML_PROMPT_ROLL 0x04
+
+#define ACPI_AML_INTERACTIVE 0x00
+#define ACPI_AML_BATCH 0x01
+
+#define circ_count(circ) \
+ (CIRC_CNT((circ)->head, (circ)->tail, ACPI_AML_BUF_SIZE))
+#define circ_count_to_end(circ) \
+ (CIRC_CNT_TO_END((circ)->head, (circ)->tail, ACPI_AML_BUF_SIZE))
+#define circ_space(circ) \
+ (CIRC_SPACE((circ)->head, (circ)->tail, ACPI_AML_BUF_SIZE))
+#define circ_space_to_end(circ) \
+ (CIRC_SPACE_TO_END((circ)->head, (circ)->tail, ACPI_AML_BUF_SIZE))
+
+#define acpi_aml_cmd_count() circ_count(&acpi_aml_cmd_crc)
+#define acpi_aml_log_count() circ_count(&acpi_aml_log_crc)
+#define acpi_aml_cmd_space() circ_space(&acpi_aml_cmd_crc)
+#define acpi_aml_log_space() circ_space(&acpi_aml_log_crc)
+
+#define ACPI_AML_DO(_fd, _op, _buf, _ret) \
+ do { \
+ _ret = acpi_aml_##_op(_fd, &acpi_aml_##_buf##_crc); \
+ if (_ret == 0) { \
+ fprintf(stderr, \
+ "%s %s pipe closed.\n", #_buf, #_op); \
+ return; \
+ } \
+ } while (0)
+#define ACPI_AML_BATCH_DO(_fd, _op, _buf, _ret) \
+ do { \
+ _ret = acpi_aml_##_op##_batch_##_buf(_fd, \
+ &acpi_aml_##_buf##_crc); \
+ if (_ret == 0) \
+ return; \
+ } while (0)
+
+
+static char acpi_aml_cmd_buf[ACPI_AML_BUF_SIZE];
+static char acpi_aml_log_buf[ACPI_AML_BUF_SIZE];
+static struct circ_buf acpi_aml_cmd_crc = {
+ .buf = acpi_aml_cmd_buf,
+ .head = 0,
+ .tail = 0,
+};
+static struct circ_buf acpi_aml_log_crc = {
+ .buf = acpi_aml_log_buf,
+ .head = 0,
+ .tail = 0,
+};
+static const char *acpi_aml_file_path = ACPI_AML_FILE;
+static unsigned long acpi_aml_mode = ACPI_AML_INTERACTIVE;
+static bool acpi_aml_exit;
+
+static bool acpi_aml_batch_drain;
+static unsigned long acpi_aml_batch_state;
+static char acpi_aml_batch_prompt;
+static char acpi_aml_batch_roll;
+static unsigned long acpi_aml_log_state;
+static char *acpi_aml_batch_cmd = NULL;
+static char *acpi_aml_batch_pos = NULL;
+
+static int acpi_aml_set_fl(int fd, int flags)
+{
+ int ret;
+
+ ret = fcntl(fd, F_GETFL, 0);
+ if (ret < 0) {
+ perror("fcntl(F_GETFL)");
+ return ret;
+ }
+ flags |= ret;
+ ret = fcntl(fd, F_SETFL, flags);
+ if (ret < 0) {
+ perror("fcntl(F_SETFL)");
+ return ret;
+ }
+ return ret;
+}
+
+static int acpi_aml_set_fd(int fd, int maxfd, fd_set *set)
+{
+ if (fd > maxfd)
+ maxfd = fd;
+ FD_SET(fd, set);
+ return maxfd;
+}
+
+static int acpi_aml_read(int fd, struct circ_buf *crc)
+{
+ char *p;
+ int len;
+
+ p = &crc->buf[crc->head];
+ len = circ_space_to_end(crc);
+ len = read(fd, p, len);
+ if (len < 0)
+ perror("read");
+ else if (len > 0)
+ crc->head = (crc->head + len) & (ACPI_AML_BUF_SIZE - 1);
+ return len;
+}
+
+static int acpi_aml_read_batch_cmd(int unused, struct circ_buf *crc)
+{
+ char *p;
+ int len;
+ int remained = strlen(acpi_aml_batch_pos);
+
+ p = &crc->buf[crc->head];
+ len = circ_space_to_end(crc);
+ if (len > remained) {
+ memcpy(p, acpi_aml_batch_pos, remained);
+ acpi_aml_batch_pos += remained;
+ len = remained;
+ } else {
+ memcpy(p, acpi_aml_batch_pos, len);
+ acpi_aml_batch_pos += len;
+ }
+ if (len > 0)
+ crc->head = (crc->head + len) & (ACPI_AML_BUF_SIZE - 1);
+ return len;
+}
+
+static int acpi_aml_read_batch_log(int fd, struct circ_buf *crc)
+{
+ char *p;
+ int len;
+ int ret = 0;
+
+ p = &crc->buf[crc->head];
+ len = circ_space_to_end(crc);
+ while (ret < len && acpi_aml_log_state != ACPI_AML_LOG_STOP) {
+ if (acpi_aml_log_state == ACPI_AML_PROMPT_ROLL) {
+ *p = acpi_aml_batch_roll;
+ len = 1;
+ crc->head = (crc->head + 1) & (ACPI_AML_BUF_SIZE - 1);
+ ret += 1;
+ acpi_aml_log_state = ACPI_AML_LOG_START;
+ } else {
+ len = read(fd, p, 1);
+ if (len <= 0) {
+ if (len < 0)
+ perror("read");
+ ret = len;
+ break;
+ }
+ }
+ switch (acpi_aml_log_state) {
+ case ACPI_AML_LOG_START:
+ if (*p == '\n')
+ acpi_aml_log_state = ACPI_AML_PROMPT_START;
+ crc->head = (crc->head + 1) & (ACPI_AML_BUF_SIZE - 1);
+ ret += 1;
+ break;
+ case ACPI_AML_PROMPT_START:
+ if (*p == ACPI_DEBUGGER_COMMAND_PROMPT ||
+ *p == ACPI_DEBUGGER_EXECUTE_PROMPT) {
+ acpi_aml_batch_prompt = *p;
+ acpi_aml_log_state = ACPI_AML_PROMPT_STOP;
+ } else {
+ if (*p != '\n')
+ acpi_aml_log_state = ACPI_AML_LOG_START;
+ crc->head = (crc->head + 1) & (ACPI_AML_BUF_SIZE - 1);
+ ret += 1;
+ }
+ break;
+ case ACPI_AML_PROMPT_STOP:
+ if (*p == ' ') {
+ acpi_aml_log_state = ACPI_AML_LOG_STOP;
+ acpi_aml_exit = true;
+ } else {
+ /* Roll back */
+ acpi_aml_log_state = ACPI_AML_PROMPT_ROLL;
+ acpi_aml_batch_roll = *p;
+ *p = acpi_aml_batch_prompt;
+ crc->head = (crc->head + 1) & (ACPI_AML_BUF_SIZE - 1);
+ ret += 1;
+ }
+ break;
+ default:
+ assert(0);
+ break;
+ }
+ }
+ return ret;
+}
+
+static int acpi_aml_write(int fd, struct circ_buf *crc)
+{
+ char *p;
+ int len;
+
+ p = &crc->buf[crc->tail];
+ len = circ_count_to_end(crc);
+ len = write(fd, p, len);
+ if (len < 0)
+ perror("write");
+ else if (len > 0)
+ crc->tail = (crc->tail + len) & (ACPI_AML_BUF_SIZE - 1);
+ return len;
+}
+
+static int acpi_aml_write_batch_log(int fd, struct circ_buf *crc)
+{
+ char *p;
+ int len;
+
+ p = &crc->buf[crc->tail];
+ len = circ_count_to_end(crc);
+ if (!acpi_aml_batch_drain) {
+ len = write(fd, p, len);
+ if (len < 0)
+ perror("write");
+ }
+ if (len > 0)
+ crc->tail = (crc->tail + len) & (ACPI_AML_BUF_SIZE - 1);
+ return len;
+}
+
+static int acpi_aml_write_batch_cmd(int fd, struct circ_buf *crc)
+{
+ int len;
+
+ len = acpi_aml_write(fd, crc);
+ if (circ_count_to_end(crc) == 0)
+ acpi_aml_batch_state = ACPI_AML_BATCH_READ_LOG;
+ return len;
+}
+
+static void acpi_aml_loop(int fd)
+{
+ fd_set rfds;
+ fd_set wfds;
+ struct timeval tv;
+ int ret;
+ int maxfd = 0;
+
+ if (acpi_aml_mode == ACPI_AML_BATCH) {
+ acpi_aml_log_state = ACPI_AML_LOG_START;
+ acpi_aml_batch_pos = acpi_aml_batch_cmd;
+ if (acpi_aml_batch_drain)
+ acpi_aml_batch_state = ACPI_AML_BATCH_READ_LOG;
+ else
+ acpi_aml_batch_state = ACPI_AML_BATCH_WRITE_CMD;
+ }
+ acpi_aml_exit = false;
+ while (!acpi_aml_exit) {
+ tv.tv_sec = ACPI_AML_SEC_TICK;
+ tv.tv_usec = 0;
+ FD_ZERO(&rfds);
+ FD_ZERO(&wfds);
+
+ if (acpi_aml_cmd_space()) {
+ if (acpi_aml_mode == ACPI_AML_INTERACTIVE)
+ maxfd = acpi_aml_set_fd(STDIN_FILENO, maxfd, &rfds);
+ else if (strlen(acpi_aml_batch_pos) &&
+ acpi_aml_batch_state == ACPI_AML_BATCH_WRITE_CMD)
+ ACPI_AML_BATCH_DO(STDIN_FILENO, read, cmd, ret);
+ }
+ if (acpi_aml_cmd_count() &&
+ (acpi_aml_mode == ACPI_AML_INTERACTIVE ||
+ acpi_aml_batch_state == ACPI_AML_BATCH_WRITE_CMD))
+ maxfd = acpi_aml_set_fd(fd, maxfd, &wfds);
+ if (acpi_aml_log_space() &&
+ (acpi_aml_mode == ACPI_AML_INTERACTIVE ||
+ acpi_aml_batch_state == ACPI_AML_BATCH_READ_LOG))
+ maxfd = acpi_aml_set_fd(fd, maxfd, &rfds);
+ if (acpi_aml_log_count())
+ maxfd = acpi_aml_set_fd(STDOUT_FILENO, maxfd, &wfds);
+
+ ret = select(maxfd+1, &rfds, &wfds, NULL, &tv);
+ if (ret < 0) {
+ perror("select");
+ break;
+ }
+ if (ret > 0) {
+ if (FD_ISSET(STDIN_FILENO, &rfds))
+ ACPI_AML_DO(STDIN_FILENO, read, cmd, ret);
+ if (FD_ISSET(fd, &wfds)) {
+ if (acpi_aml_mode == ACPI_AML_BATCH)
+ ACPI_AML_BATCH_DO(fd, write, cmd, ret);
+ else
+ ACPI_AML_DO(fd, write, cmd, ret);
+ }
+ if (FD_ISSET(fd, &rfds)) {
+ if (acpi_aml_mode == ACPI_AML_BATCH)
+ ACPI_AML_BATCH_DO(fd, read, log, ret);
+ else
+ ACPI_AML_DO(fd, read, log, ret);
+ }
+ if (FD_ISSET(STDOUT_FILENO, &wfds)) {
+ if (acpi_aml_mode == ACPI_AML_BATCH)
+ ACPI_AML_BATCH_DO(STDOUT_FILENO, write, log, ret);
+ else
+ ACPI_AML_DO(STDOUT_FILENO, write, log, ret);
+ }
+ }
+ }
+}
+
+static bool acpi_aml_readable(int fd)
+{
+ fd_set rfds;
+ struct timeval tv;
+ int ret;
+ int maxfd = 0;
+
+ tv.tv_sec = 0;
+ tv.tv_usec = ACPI_AML_USEC_PEEK;
+ FD_ZERO(&rfds);
+ maxfd = acpi_aml_set_fd(fd, maxfd, &rfds);
+ ret = select(maxfd+1, &rfds, NULL, NULL, &tv);
+ if (ret < 0)
+ perror("select");
+ if (ret > 0 && FD_ISSET(fd, &rfds))
+ return true;
+ return false;
+}
+
+/*
+ * This is a userspace IO flush implementation, replying on the prompt
+ * characters and can be turned into a flush() call after kernel implements
+ * .flush() filesystem operation.
+ */
+static void acpi_aml_flush(int fd)
+{
+ while (acpi_aml_readable(fd)) {
+ acpi_aml_batch_drain = true;
+ acpi_aml_loop(fd);
+ acpi_aml_batch_drain = false;
+ }
+}
+
+void usage(FILE *file, char *progname)
+{
+ fprintf(file, "usage: %s [-b cmd] [-f file] [-h]\n", progname);
+ fprintf(file, "\nOptions:\n");
+ fprintf(file, " -b Specify command to be executed in batch mode\n");
+ fprintf(file, " -f Specify interface file other than");
+ fprintf(file, " /sys/kernel/debug/acpi/aml\n");
+ fprintf(file, " -h Print this help message\n");
+}
+
+int main(int argc, char **argv)
+{
+ int fd = 0;
+ int ch;
+ int len;
+ int ret = EXIT_SUCCESS;
+
+ while ((ch = getopt(argc, argv, "b:f:h")) != -1) {
+ switch (ch) {
+ case 'b':
+ if (acpi_aml_batch_cmd) {
+ fprintf(stderr, "Already specify %s\n",
+ acpi_aml_batch_cmd);
+ ret = EXIT_FAILURE;
+ goto exit;
+ }
+ len = strlen(optarg);
+ acpi_aml_batch_cmd = calloc(len + 2, 1);
+ if (!acpi_aml_batch_cmd) {
+ perror("calloc");
+ ret = EXIT_FAILURE;
+ goto exit;
+ }
+ memcpy(acpi_aml_batch_cmd, optarg, len);
+ acpi_aml_batch_cmd[len] = '\n';
+ acpi_aml_mode = ACPI_AML_BATCH;
+ break;
+ case 'f':
+ acpi_aml_file_path = optarg;
+ break;
+ case 'h':
+ usage(stdout, argv[0]);
+ goto exit;
+ break;
+ case '?':
+ default:
+ usage(stderr, argv[0]);
+ ret = EXIT_FAILURE;
+ goto exit;
+ break;
+ }
+ }
+
+ fd = open(acpi_aml_file_path, O_RDWR | O_NONBLOCK);
+ if (fd < 0) {
+ perror("open");
+ ret = EXIT_FAILURE;
+ goto exit;
+ }
+ acpi_aml_set_fl(STDIN_FILENO, O_NONBLOCK);
+ acpi_aml_set_fl(STDOUT_FILENO, O_NONBLOCK);
+
+ if (acpi_aml_mode == ACPI_AML_BATCH)
+ acpi_aml_flush(fd);
+ acpi_aml_loop(fd);
+
+exit:
+ if (fd < 0)
+ close(fd);
+ if (acpi_aml_batch_cmd)
+ free(acpi_aml_batch_cmd);
+ return ret;
+}
--
1.7.10

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