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-rw-r--r--src/shared/acpi-fpdt.c147
1 files changed, 147 insertions, 0 deletions
diff --git a/src/shared/acpi-fpdt.c b/src/shared/acpi-fpdt.c
new file mode 100644
index 0000000..d565ebd
--- /dev/null
+++ b/src/shared/acpi-fpdt.c
@@ -0,0 +1,147 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <errno.h>
+#include <fcntl.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "acpi-fpdt.h"
+#include "alloc-util.h"
+#include "fd-util.h"
+#include "fileio.h"
+#include "time-util.h"
+
+struct acpi_table_header {
+ char signature[4];
+ uint32_t length;
+ uint8_t revision;
+ uint8_t checksum;
+ char oem_id[6];
+ char oem_table_id[8];
+ uint32_t oem_revision;
+ char asl_compiler_id[4];
+ uint32_t asl_compiler_revision;
+};
+
+enum {
+ ACPI_FPDT_TYPE_BOOT = 0,
+ ACPI_FPDT_TYPE_S3PERF = 1,
+};
+
+struct acpi_fpdt_header {
+ uint16_t type;
+ uint8_t length;
+ uint8_t revision;
+ uint8_t reserved[4];
+ uint64_t ptr;
+};
+
+struct acpi_fpdt_boot_header {
+ char signature[4];
+ uint32_t length;
+};
+
+enum {
+ ACPI_FPDT_S3PERF_RESUME_REC = 0,
+ ACPI_FPDT_S3PERF_SUSPEND_REC = 1,
+ ACPI_FPDT_BOOT_REC = 2,
+};
+
+struct acpi_fpdt_boot {
+ uint16_t type;
+ uint8_t length;
+ uint8_t revision;
+ uint8_t reserved[4];
+ uint64_t reset_end;
+ uint64_t load_start;
+ uint64_t startup_start;
+ uint64_t exit_services_entry;
+ uint64_t exit_services_exit;
+};
+
+int acpi_get_boot_usec(usec_t *loader_start, usec_t *loader_exit) {
+ _cleanup_free_ char *buf = NULL;
+ struct acpi_table_header *tbl;
+ size_t l = 0;
+ struct acpi_fpdt_header *rec;
+ int r;
+ uint64_t ptr = 0;
+ _cleanup_close_ int fd = -1;
+ struct acpi_fpdt_boot_header hbrec;
+ struct acpi_fpdt_boot brec;
+
+ r = read_full_file("/sys/firmware/acpi/tables/FPDT", &buf, &l);
+ if (r < 0)
+ return r;
+
+ if (l < sizeof(struct acpi_table_header) + sizeof(struct acpi_fpdt_header))
+ return -EINVAL;
+
+ tbl = (struct acpi_table_header *)buf;
+ if (l != tbl->length)
+ return -EINVAL;
+
+ if (memcmp(tbl->signature, "FPDT", 4) != 0)
+ return -EINVAL;
+
+ /* find Firmware Basic Boot Performance Pointer Record */
+ for (rec = (struct acpi_fpdt_header *)(buf + sizeof(struct acpi_table_header));
+ (char *)rec < buf + l;
+ rec = (struct acpi_fpdt_header *)((char *)rec + rec->length)) {
+ if (rec->length <= 0)
+ break;
+ if (rec->type != ACPI_FPDT_TYPE_BOOT)
+ continue;
+ if (rec->length != sizeof(struct acpi_fpdt_header))
+ continue;
+
+ ptr = rec->ptr;
+ break;
+ }
+
+ if (ptr == 0)
+ return -ENODATA;
+
+ /* read Firmware Basic Boot Performance Data Record */
+ fd = open("/dev/mem", O_CLOEXEC|O_RDONLY);
+ if (fd < 0)
+ return -errno;
+
+ l = pread(fd, &hbrec, sizeof(struct acpi_fpdt_boot_header), ptr);
+ if (l != sizeof(struct acpi_fpdt_boot_header))
+ return -EINVAL;
+
+ if (memcmp(hbrec.signature, "FBPT", 4) != 0)
+ return -EINVAL;
+
+ if (hbrec.length < sizeof(struct acpi_fpdt_boot_header) + sizeof(struct acpi_fpdt_boot))
+ return -EINVAL;
+
+ l = pread(fd, &brec, sizeof(struct acpi_fpdt_boot), ptr + sizeof(struct acpi_fpdt_boot_header));
+ if (l != sizeof(struct acpi_fpdt_boot))
+ return -EINVAL;
+
+ if (brec.length != sizeof(struct acpi_fpdt_boot))
+ return -EINVAL;
+
+ if (brec.type != ACPI_FPDT_BOOT_REC)
+ return -EINVAL;
+
+ if (brec.exit_services_exit == 0)
+ /* Non-UEFI compatible boot. */
+ return -ENODATA;
+
+ if (brec.startup_start == 0 || brec.exit_services_exit < brec.startup_start)
+ return -EINVAL;
+ if (brec.exit_services_exit > NSEC_PER_HOUR)
+ return -EINVAL;
+
+ if (loader_start)
+ *loader_start = brec.startup_start / 1000;
+ if (loader_exit)
+ *loader_exit = brec.exit_services_exit / 1000;
+
+ return 0;
+}