[PATCH v16 07/11] fw_cfg: add a public uapi header

Marc-André Lureau
2018-02-28T15:06:50Z

Create a common header file for well-known values and structures to be
shared by the Linux kernel with qemu or other projects.

It is based from qemu/docs/specs/fw_cfg.txt which references
qemu/include/hw/nvram/fw_cfg_keys.h "for the most up-to-date and
authoritative list" & vmcoreinfo.txt. Those files don't have an
explicit license, but qemu/hw/nvram/fw_cfg.c is BSD-license, so
Michael S. Tsirkin suggested to use the same license.

The patch intentionally left out DMA & vmcoreinfo structures &
defines, which are added in the commits making usage of it.

Suggested-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>

---

The related qemu patch making use of it, to be submitted:
https://github.com/elmarco/qemu/commit/4884fc9e9c4c4467a371e5a40f3181239e1b70f5
---
MAINTAINERS | 1 +
drivers/firmware/qemu_fw_cfg.c | 22 ++------------
include/uapi/linux/qemu_fw_cfg.h | 66 ++++++++++++++++++++++++++++++++++++++++
3 files changed, 69 insertions(+), 20 deletions(-)
create mode 100644 include/uapi/linux/qemu_fw_cfg.h

diff --git a/MAINTAINERS b/MAINTAINERS
index 93a12af4f180..0ce1b3e536fd 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -11353,6 +11353,7 @@ M: "Michael S. Tsirkin" <mst@redhat.com>
L: qemu-devel@nongnu.org
S: Maintained
F: drivers/firmware/qemu_fw_cfg.c
+F: include/uapi/linux/qemu_fw_cfg.h

QIB DRIVER
M: Dennis Dalessandro <dennis.dalessandro@intel.com>
diff --git a/drivers/firmware/qemu_fw_cfg.c b/drivers/firmware/qemu_fw_cfg.c
index 45bfc389b226..5de6bb406fb6 100644
--- a/drivers/firmware/qemu_fw_cfg.c
+++ b/drivers/firmware/qemu_fw_cfg.c
@@ -32,30 +32,12 @@
#include <linux/slab.h>
#include <linux/io.h>
#include <linux/ioport.h>
+#include <uapi/linux/qemu_fw_cfg.h>

MODULE_AUTHOR("Gabriel L. Somlo <somlo@cmu.edu>");
MODULE_DESCRIPTION("QEMU fw_cfg sysfs support");
MODULE_LICENSE("GPL");

-/* selector key values for "well-known" fw_cfg entries */
-#define FW_CFG_SIGNATURE 0x00
-#define FW_CFG_ID 0x01
-#define FW_CFG_FILE_DIR 0x19
-
-/* size in bytes of fw_cfg signature */
-#define FW_CFG_SIG_SIZE 4
-
-/* fw_cfg "file name" is up to 56 characters (including terminating nul) */
-#define FW_CFG_MAX_FILE_PATH 56
-
-/* fw_cfg file directory entry type */
-struct fw_cfg_file {
- u32 size;
- u16 select;
- u16 reserved;
- char name[FW_CFG_MAX_FILE_PATH];
-};
-
/* fw_cfg device i/o register addresses */
static bool fw_cfg_is_mmio;
static phys_addr_t fw_cfg_p_base;
@@ -616,7 +598,7 @@ MODULE_DEVICE_TABLE(of, fw_cfg_sysfs_mmio_match);

#ifdef CONFIG_ACPI
static const struct acpi_device_id fw_cfg_sysfs_acpi_match[] = {
- { "QEMU0002", },
+ { FW_CFG_ACPI_DEVICE_ID, },
{},
};
MODULE_DEVICE_TABLE(acpi, fw_cfg_sysfs_acpi_match);
diff --git a/include/uapi/linux/qemu_fw_cfg.h b/include/uapi/linux/qemu_fw_cfg.h
new file mode 100644
index 000000000000..c698ac3812f6
--- /dev/null
+++ b/include/uapi/linux/qemu_fw_cfg.h
@@ -0,0 +1,66 @@
+/* SPDX-License-Identifier: BSD-3-Clause */
+#ifndef _LINUX_FW_CFG_H
+#define _LINUX_FW_CFG_H
+
+#include <linux/types.h>
+
+#define FW_CFG_ACPI_DEVICE_ID "QEMU0002"
+
+/* selector key values for "well-known" fw_cfg entries */
+#define FW_CFG_SIGNATURE 0x00
+#define FW_CFG_ID 0x01
+#define FW_CFG_UUID 0x02
+#define FW_CFG_RAM_SIZE 0x03
+#define FW_CFG_NOGRAPHIC 0x04
+#define FW_CFG_NB_CPUS 0x05
+#define FW_CFG_MACHINE_ID 0x06
+#define FW_CFG_KERNEL_ADDR 0x07
+#define FW_CFG_KERNEL_SIZE 0x08
+#define FW_CFG_KERNEL_CMDLINE 0x09
+#define FW_CFG_INITRD_ADDR 0x0a
+#define FW_CFG_INITRD_SIZE 0x0b
+#define FW_CFG_BOOT_DEVICE 0x0c
+#define FW_CFG_NUMA 0x0d
+#define FW_CFG_BOOT_MENU 0x0e
+#define FW_CFG_MAX_CPUS 0x0f
+#define FW_CFG_KERNEL_ENTRY 0x10
+#define FW_CFG_KERNEL_DATA 0x11
+#define FW_CFG_INITRD_DATA 0x12
+#define FW_CFG_CMDLINE_ADDR 0x13
+#define FW_CFG_CMDLINE_SIZE 0x14
+#define FW_CFG_CMDLINE_DATA 0x15
+#define FW_CFG_SETUP_ADDR 0x16
+#define FW_CFG_SETUP_SIZE 0x17
+#define FW_CFG_SETUP_DATA 0x18
+#define FW_CFG_FILE_DIR 0x19
+
+#define FW_CFG_FILE_FIRST 0x20
+#define FW_CFG_FILE_SLOTS_MIN 0x10
+
+#define FW_CFG_WRITE_CHANNEL 0x4000
+#define FW_CFG_ARCH_LOCAL 0x8000
+#define FW_CFG_ENTRY_MASK (~(FW_CFG_WRITE_CHANNEL | FW_CFG_ARCH_LOCAL))
+
+#define FW_CFG_INVALID 0xffff
+
+/* width in bytes of fw_cfg control register */
+#define FW_CFG_CTL_SIZE 0x02
+
+/* fw_cfg "file name" is up to 56 characters (including terminating nul) */
+#define FW_CFG_MAX_FILE_PATH 56
+
+/* size in bytes of fw_cfg signature */
+#define FW_CFG_SIG_SIZE 4
+
+/* FW_CFG_ID bits */
+#define FW_CFG_VERSION 0x01
+
+/* fw_cfg file directory entry type */
+struct fw_cfg_file {
+ __be32 size;
+ __be16 select;
+ __u16 reserved;
+ char name[FW_CFG_MAX_FILE_PATH];
+};
+
+#endif
--
2.16.1.73.g5832b7e9f2