fw_cfg: add a public uapi header

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>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

diff --git a/MAINTAINERS b/MAINTAINERS
index 4623caf8d72d8591b87a300b35b5ad0aca10f6a5..fc2c373f24a0ec5d1c00b9ebe83026b2a050706a 100644 (file)
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -11368,6 +11368,7 @@ 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 45bfc389b2261b8ffe2ed45c845c6dbf9b6650c6..5de6bb406fb673629d2c00054e5c2a956bc94f4e 100644 (file)
--- 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 (file)
index 0000000..c698ac3
--- /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