5 files changed, 72 insertions, 18 deletions

diff --git a/arch/s390/boot/als.c b/arch/s390/boot/als.c
index d592e0d90d9f..f902215e9cd9 100644
--- a/arch/s390/boot/als.c
+++ b/arch/s390/boot/als.c
@@ -7,6 +7,7 @@
 #include <asm/facility.h>
 #include <asm/lowcore.h>
 #include <asm/sclp.h>
+#include "boot.h"
 
 /*
  * The code within this file will be called very early. It may _not_
@@ -58,7 +59,7 @@ static void u16_to_decimal(char *str, u16 val)
 	*str = '\0';
 }
 
-static void print_missing_facilities(void)
+void print_missing_facilities(void)
 {
 	static char als_str[80] = "Missing facilities: ";
 	unsigned long val;
@@ -90,7 +91,6 @@ static void print_missing_facilities(void)
 	}
 	strcat(als_str, "\n");
 	sclp_early_printk(als_str);
-	sclp_early_printk("See Principles of Operations for facility bits\n");
 }
 
 static void facility_mismatch(void)
@@ -98,6 +98,7 @@ static void facility_mismatch(void)
 	sclp_early_printk("The Linux kernel requires more recent processor hardware\n");
 	print_machine_type();
 	print_missing_facilities();
+	sclp_early_printk("See Principles of Operations for facility bits\n");
 	disabled_wait(0x8badcccc);
 }
 
@@ -105,20 +106,7 @@ void verify_facilities(void)
 {
 	int i;
 
-	for (i = 0; i < ARRAY_SIZE(S390_lowcore.stfle_fac_list); i++)
-		S390_lowcore.stfle_fac_list[i] = 0;
-	asm volatile(
-		"	stfl	0(0)\n"
-		: "=m" (S390_lowcore.stfl_fac_list));
-	S390_lowcore.stfle_fac_list[0] = (u64)S390_lowcore.stfl_fac_list << 32;
-	if (S390_lowcore.stfl_fac_list & 0x01000000) {
-		register unsigned long reg0 asm("0") = ARRAY_SIZE(als) - 1;
-
-		asm volatile(".insn s,0xb2b00000,0(%1)" /* stfle */
-			     : "+d" (reg0)
-			     : "a" (&S390_lowcore.stfle_fac_list)
-			     : "memory", "cc");
-	}
+	__stfle(S390_lowcore.stfle_fac_list, ARRAY_SIZE(S390_lowcore.stfle_fac_list));
 	for (i = 0; i < ARRAY_SIZE(als); i++) {
 		if ((S390_lowcore.stfle_fac_list[i] & als[i]) != als[i])
 			facility_mismatch();
diff --git a/arch/s390/boot/boot.h b/arch/s390/boot/boot.h
index fc41e2277ea8..82bc06346e05 100644
--- a/arch/s390/boot/boot.h
+++ b/arch/s390/boot/boot.h
@@ -6,6 +6,8 @@ void startup_kernel(void);
 void detect_memory(void);
 void store_ipl_parmblock(void);
 void setup_boot_command_line(void);
+void parse_boot_command_line(void);
 void setup_memory_end(void);
+void print_missing_facilities(void);
 
 #endif /* BOOT_BOOT_H */
diff --git a/arch/s390/boot/ipl_parm.c b/arch/s390/boot/ipl_parm.c
index 9dab596be98e..36beb56de021 100644
--- a/arch/s390/boot/ipl_parm.c
+++ b/arch/s390/boot/ipl_parm.c
@@ -1,10 +1,12 @@
 // SPDX-License-Identifier: GPL-2.0
+#include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/ctype.h>
 #include <asm/ebcdic.h>
 #include <asm/sclp.h>
 #include <asm/sections.h>
 #include <asm/boot_data.h>
+#include <asm/facility.h>
 #include "boot.h"
 
 char __bootdata(early_command_line)[COMMAND_LINE_SIZE];
@@ -143,8 +145,66 @@ void setup_boot_command_line(void)
 		append_ipl_block_parm();
 }
 
+static void modify_facility(unsigned long nr, bool clear)
+{
+	if (clear)
+		__clear_facility(nr, S390_lowcore.stfle_fac_list);
+	else
+		__set_facility(nr, S390_lowcore.stfle_fac_list);
+}
+
+static void check_cleared_facilities(void)
+{
+	unsigned long als[] = { FACILITIES_ALS };
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(als); i++) {
+		if ((S390_lowcore.stfle_fac_list[i] & als[i]) != als[i]) {
+			sclp_early_printk("Warning: The Linux kernel requires facilities cleared via command line option\n");
+			print_missing_facilities();
+			break;
+		}
+	}
+}
+
+static void modify_fac_list(char *str)
+{
+	unsigned long val, endval;
+	char *endp;
+	bool clear;
+
+	while (*str) {
+		clear = false;
+		if (*str == '!') {
+			clear = true;
+			str++;
+		}
+		val = simple_strtoull(str, &endp, 0);
+		if (str == endp)
+			break;
+		str = endp;
+		if (*str == '-') {
+			str++;
+			endval = simple_strtoull(str, &endp, 0);
+			if (str == endp)
+				break;
+			str = endp;
+			while (val <= endval) {
+				modify_facility(val, clear);
+				val++;
+			}
+		} else {
+			modify_facility(val, clear);
+		}
+		if (*str != ',')
+			break;
+		str++;
+	}
+	check_cleared_facilities();
+}
+
 static char command_line_buf[COMMAND_LINE_SIZE] __section(.data);
-static void parse_mem_opt(void)
+void parse_boot_command_line(void)
 {
 	char *param, *val;
 	bool enabled;
@@ -165,12 +225,14 @@ static void parse_mem_opt(void)
 			if (!rc && !enabled)
 				noexec_disabled = 1;
 		}
+
+		if (!strcmp(param, "facilities"))
+			modify_fac_list(val);
 	}
 }
 
 void setup_memory_end(void)
 {
-	parse_mem_opt();
 #ifdef CONFIG_CRASH_DUMP
 	if (!OLDMEM_BASE && early_ipl_block_valid &&
 	    early_ipl_block.hdr.pbt == DIAG308_IPL_TYPE_FCP &&
diff --git a/arch/s390/boot/startup.c b/arch/s390/boot/startup.c
index 4d441317cdeb..bdfc5549a299 100644
--- a/arch/s390/boot/startup.c
+++ b/arch/s390/boot/startup.c
@@ -53,6 +53,7 @@ void startup_kernel(void)
 	sclp_early_read_info();
 	store_ipl_parmblock();
 	setup_boot_command_line();
+	parse_boot_command_line();
 	setup_memory_end();
 	detect_memory();
 	if (!IS_ENABLED(CONFIG_KERNEL_UNCOMPRESSED)) {
diff --git a/arch/s390/boot/string.c b/arch/s390/boot/string.c
index 25aca07898ba..b11e8108773a 100644
--- a/arch/s390/boot/string.c
+++ b/arch/s390/boot/string.c
@@ -2,6 +2,7 @@
 #include <linux/ctype.h>
 #include <linux/kernel.h>
 #include <linux/errno.h>
+#undef CONFIG_KASAN
 #include "../lib/string.c"
 
 int strncmp(const char *cs, const char *ct, size_t count)