efi/libstub: Add efi_warn and *_once logging helpers

Add an efi_warn logging helper for warnings, and implement an analog of
printk_once for once-only logging.

Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Link: https://lore.kernel.org/r/20200914213535.933454-1-nivedita@alum.mit.edu
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

diff --git a/drivers/firmware/efi/libstub/efistub.h b/drivers/firmware/efi/libstub/efistub.h
index 27cdcb1..9ea87a2 100644 (file)
--- a/drivers/firmware/efi/libstub/efistub.h
+++ b/drivers/firmware/efi/libstub/efistub.h
@@ -52,11 +52,34 @@ efi_status_t __efiapi efi_pe_entry(efi_handle_t handle,
 
 #define efi_info(fmt, ...) \
        efi_printk(KERN_INFO fmt, ##__VA_ARGS__)
+#define efi_warn(fmt, ...) \
+       efi_printk(KERN_WARNING "WARNING: " fmt, ##__VA_ARGS__)
 #define efi_err(fmt, ...) \
        efi_printk(KERN_ERR "ERROR: " fmt, ##__VA_ARGS__)
 #define efi_debug(fmt, ...) \
        efi_printk(KERN_DEBUG "DEBUG: " fmt, ##__VA_ARGS__)
 
+#define efi_printk_once(fmt, ...)              \
+({                                             \
+       static bool __print_once;               \
+       bool __ret_print_once = !__print_once;  \
+                                               \
+       if (!__print_once) {                    \
+               __print_once = true;            \
+               efi_printk(fmt, ##__VA_ARGS__); \
+       }                                       \
+       __ret_print_once;                       \
+})
+
+#define efi_info_once(fmt, ...) \
+       efi_printk_once(KERN_INFO fmt, ##__VA_ARGS__)
+#define efi_warn_once(fmt, ...) \
+       efi_printk_once(KERN_WARNING "WARNING: " fmt, ##__VA_ARGS__)
+#define efi_err_once(fmt, ...) \
+       efi_printk_once(KERN_ERR "ERROR: " fmt, ##__VA_ARGS__)
+#define efi_debug_once(fmt, ...) \
+       efi_printk_once(KERN_DEBUG "DEBUG: " fmt, ##__VA_ARGS__)
+
 /* Helper macros for the usual case of using simple C variables: */
 #ifndef fdt_setprop_inplace_var
 #define fdt_setprop_inplace_var(fdt, node_offset, name, var) \