[tip: efi/core] efi/libstub: Add efi_warn and *_once logging helpers

[tip-bot2 for Arvind Sankar]

The following commit has been merged into the efi/core branch of tip:

Commit-ID:     c1df5e0c5796f775e60d1aec0b52f6d03d66ccd4
Gitweb:        https://git.kernel.org/tip/c1df5e0c5796f775e60d1aec0b52f6d03d66ccd4
Author:        Arvind Sankar <nivedita@xxxxxxxxxxxx>
AuthorDate:    Mon, 14 Sep 2020 17:35:34 -04:00
Committer:     Ard Biesheuvel <ardb@xxxxxxxxxx>
CommitterDate: Wed, 16 Sep 2020 18:53:42 +03:00

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@xxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20200914213535.933454-1-nivedita@xxxxxxxxxxxx
Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx>
---
 drivers/firmware/efi/libstub/efistub.h | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/drivers/firmware/efi/libstub/efistub.h b/drivers/firmware/efi/libstub/efistub.h
index 27cdcb1..9ea87a2 100644
--- 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) \