1 files changed, 319 insertions, 0 deletions
diff --git a/arch/s390/kernel/early.c b/arch/s390/kernel/early.c
new file mode 100644
index 000000000..985e1e755
--- /dev/null
+++ b/arch/s390/kernel/early.c
@@ -0,0 +1,319 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *    Copyright IBM Corp. 2007, 2009
+ *    Author(s): Hongjie Yang <hongjie@us.ibm.com>,
+ *		 Heiko Carstens <heiko.carstens@de.ibm.com>
+ */
+
+#define KMSG_COMPONENT "setup"
+#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
+
+#include <linux/compiler.h>
+#include <linux/init.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/ctype.h>
+#include <linux/lockdep.h>
+#include <linux/extable.h>
+#include <linux/pfn.h>
+#include <linux/uaccess.h>
+#include <linux/kernel.h>
+#include <asm/diag.h>
+#include <asm/ebcdic.h>
+#include <asm/ipl.h>
+#include <asm/lowcore.h>
+#include <asm/processor.h>
+#include <asm/sections.h>
+#include <asm/setup.h>
+#include <asm/sysinfo.h>
+#include <asm/cpcmd.h>
+#include <asm/sclp.h>
+#include <asm/facility.h>
+#include <asm/boot_data.h>
+#include <asm/switch_to.h>
+#include "entry.h"
+
+static void __init reset_tod_clock(void)
+{
+	u64 time;
+
+	if (store_tod_clock(&time) == 0)
+		return;
+	/* TOD clock not running. Set the clock to Unix Epoch. */
+	if (set_tod_clock(TOD_UNIX_EPOCH) != 0 || store_tod_clock(&time) != 0)
+		disabled_wait();
+
+	memset(tod_clock_base, 0, 16);
+	*(__u64 *) &tod_clock_base[1] = TOD_UNIX_EPOCH;
+	S390_lowcore.last_update_clock = TOD_UNIX_EPOCH;
+}
+
+/*
+ * Initialize storage key for kernel pages
+ */
+static noinline __init void init_kernel_storage_key(void)
+{
+#if PAGE_DEFAULT_KEY
+	unsigned long end_pfn, init_pfn;
+
+	end_pfn = PFN_UP(__pa(_end));
+
+	for (init_pfn = 0 ; init_pfn < end_pfn; init_pfn++)
+		page_set_storage_key(init_pfn << PAGE_SHIFT,
+				     PAGE_DEFAULT_KEY, 0);
+#endif
+}
+
+static __initdata char sysinfo_page[PAGE_SIZE] __aligned(PAGE_SIZE);
+
+static noinline __init void detect_machine_type(void)
+{
+	struct sysinfo_3_2_2 *vmms = (struct sysinfo_3_2_2 *)&sysinfo_page;
+
+	/* Check current-configuration-level */
+	if (stsi(NULL, 0, 0, 0) <= 2) {
+		S390_lowcore.machine_flags |= MACHINE_FLAG_LPAR;
+		return;
+	}
+	/* Get virtual-machine cpu information. */
+	if (stsi(vmms, 3, 2, 2) || !vmms->count)
+		return;
+
+	/* Detect known hypervisors */
+	if (!memcmp(vmms->vm[0].cpi, "\xd2\xe5\xd4", 3))
+		S390_lowcore.machine_flags |= MACHINE_FLAG_KVM;
+	else if (!memcmp(vmms->vm[0].cpi, "\xa9\x61\xe5\xd4", 4))
+		S390_lowcore.machine_flags |= MACHINE_FLAG_VM;
+}
+
+/* Remove leading, trailing and double whitespace. */
+static inline void strim_all(char *str)
+{
+	char *s;
+
+	s = strim(str);
+	if (s != str)
+		memmove(str, s, strlen(s));
+	while (*str) {
+		if (!isspace(*str++))
+			continue;
+		if (isspace(*str)) {
+			s = skip_spaces(str);
+			memmove(str, s, strlen(s) + 1);
+		}
+	}
+}
+
+static noinline __init void setup_arch_string(void)
+{
+	struct sysinfo_1_1_1 *mach = (struct sysinfo_1_1_1 *)&sysinfo_page;
+	struct sysinfo_3_2_2 *vm = (struct sysinfo_3_2_2 *)&sysinfo_page;
+	char mstr[80], hvstr[17];
+
+	if (stsi(mach, 1, 1, 1))
+		return;
+	EBCASC(mach->manufacturer, sizeof(mach->manufacturer));
+	EBCASC(mach->type, sizeof(mach->type));
+	EBCASC(mach->model, sizeof(mach->model));
+	EBCASC(mach->model_capacity, sizeof(mach->model_capacity));
+	sprintf(mstr, "%-16.16s %-4.4s %-16.16s %-16.16s",
+		mach->manufacturer, mach->type,
+		mach->model, mach->model_capacity);
+	strim_all(mstr);
+	if (stsi(vm, 3, 2, 2) == 0 && vm->count) {
+		EBCASC(vm->vm[0].cpi, sizeof(vm->vm[0].cpi));
+		sprintf(hvstr, "%-16.16s", vm->vm[0].cpi);
+		strim_all(hvstr);
+	} else {
+		sprintf(hvstr, "%s",
+			MACHINE_IS_LPAR ? "LPAR" :
+			MACHINE_IS_VM ? "z/VM" :
+			MACHINE_IS_KVM ? "KVM" : "unknown");
+	}
+	dump_stack_set_arch_desc("%s (%s)", mstr, hvstr);
+}
+
+static __init void setup_topology(void)
+{
+	int max_mnest;
+
+	if (!test_facility(11))
+		return;
+	S390_lowcore.machine_flags |= MACHINE_FLAG_TOPOLOGY;
+	for (max_mnest = 6; max_mnest > 1; max_mnest--) {
+		if (stsi(&sysinfo_page, 15, 1, max_mnest) == 0)
+			break;
+	}
+	topology_max_mnest = max_mnest;
+}
+
+static void early_pgm_check_handler(void)
+{
+	const struct exception_table_entry *fixup;
+	unsigned long cr0, cr0_new;
+	unsigned long addr;
+
+	addr = S390_lowcore.program_old_psw.addr;
+	fixup = s390_search_extables(addr);
+	if (!fixup)
+		disabled_wait();
+	/* Disable low address protection before storing into lowcore. */
+	__ctl_store(cr0, 0, 0);
+	cr0_new = cr0 & ~(1UL << 28);
+	__ctl_load(cr0_new, 0, 0);
+	S390_lowcore.program_old_psw.addr = extable_fixup(fixup);
+	__ctl_load(cr0, 0, 0);
+}
+
+static noinline __init void setup_lowcore_early(void)
+{
+	psw_t psw;
+
+	psw.mask = PSW_MASK_BASE | PSW_DEFAULT_KEY | PSW_MASK_EA | PSW_MASK_BA;
+	if (IS_ENABLED(CONFIG_KASAN))
+		psw.mask |= PSW_MASK_DAT;
+	psw.addr = (unsigned long) s390_base_ext_handler;
+	S390_lowcore.external_new_psw = psw;
+	psw.addr = (unsigned long) s390_base_pgm_handler;
+	S390_lowcore.program_new_psw = psw;
+	s390_base_pgm_handler_fn = early_pgm_check_handler;
+	S390_lowcore.preempt_count = INIT_PREEMPT_COUNT;
+}
+
+static noinline __init void setup_facility_list(void)
+{
+	memcpy(S390_lowcore.alt_stfle_fac_list,
+	       S390_lowcore.stfle_fac_list,
+	       sizeof(S390_lowcore.alt_stfle_fac_list));
+	if (!IS_ENABLED(CONFIG_KERNEL_NOBP))
+		__clear_facility(82, S390_lowcore.alt_stfle_fac_list);
+}
+
+static __init void detect_diag9c(void)
+{
+	unsigned int cpu_address;
+	int rc;
+
+	cpu_address = stap();
+	diag_stat_inc(DIAG_STAT_X09C);
+	asm volatile(
+		"	diag	%2,0,0x9c\n"
+		"0:	la	%0,0\n"
+		"1:\n"
+		EX_TABLE(0b,1b)
+		: "=d" (rc) : "0" (-EOPNOTSUPP), "d" (cpu_address) : "cc");
+	if (!rc)
+		S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG9C;
+}
+
+static __init void detect_machine_facilities(void)
+{
+	if (test_facility(8)) {
+		S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT1;
+		__ctl_set_bit(0, 23);
+	}
+	if (test_facility(78))
+		S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT2;
+	if (test_facility(3))
+		S390_lowcore.machine_flags |= MACHINE_FLAG_IDTE;
+	if (test_facility(50) && test_facility(73)) {
+		S390_lowcore.machine_flags |= MACHINE_FLAG_TE;
+		__ctl_set_bit(0, 55);
+	}
+	if (test_facility(51))
+		S390_lowcore.machine_flags |= MACHINE_FLAG_TLB_LC;
+	if (test_facility(129)) {
+		S390_lowcore.machine_flags |= MACHINE_FLAG_VX;
+		__ctl_set_bit(0, 17);
+	}
+	if (test_facility(130) && !noexec_disabled) {
+		S390_lowcore.machine_flags |= MACHINE_FLAG_NX;
+		__ctl_set_bit(0, 20);
+	}
+	if (test_facility(133))
+		S390_lowcore.machine_flags |= MACHINE_FLAG_GS;
+	if (test_facility(139) && (tod_clock_base[1] & 0x80)) {
+		/* Enabled signed clock comparator comparisons */
+		S390_lowcore.machine_flags |= MACHINE_FLAG_SCC;
+		clock_comparator_max = -1ULL >> 1;
+		__ctl_set_bit(0, 53);
+	}
+	if (IS_ENABLED(CONFIG_PCI) && test_facility(153)) {
+		S390_lowcore.machine_flags |= MACHINE_FLAG_PCI_MIO;
+		/* the control bit is set during PCI initialization */
+	}
+}
+
+static inline void save_vector_registers(void)
+{
+#ifdef CONFIG_CRASH_DUMP
+	if (test_facility(129))
+		save_vx_regs(boot_cpu_vector_save_area);
+#endif
+}
+
+static inline void setup_control_registers(void)
+{
+	unsigned long reg;
+
+	__ctl_store(reg, 0, 0);
+	reg |= CR0_LOW_ADDRESS_PROTECTION;
+	reg |= CR0_EMERGENCY_SIGNAL_SUBMASK;
+	reg |= CR0_EXTERNAL_CALL_SUBMASK;
+	__ctl_load(reg, 0, 0);
+}
+
+static inline void setup_access_registers(void)
+{
+	unsigned int acrs[NUM_ACRS] = { 0 };
+
+	restore_access_regs(acrs);
+}
+
+static int __init disable_vector_extension(char *str)
+{
+	S390_lowcore.machine_flags &= ~MACHINE_FLAG_VX;
+	__ctl_clear_bit(0, 17);
+	return 0;
+}
+early_param("novx", disable_vector_extension);
+
+char __bootdata(early_command_line)[COMMAND_LINE_SIZE];
+static void __init setup_boot_command_line(void)
+{
+	/* copy arch command line */
+	strlcpy(boot_command_line, early_command_line, ARCH_COMMAND_LINE_SIZE);
+}
+
+static void __init check_image_bootable(void)
+{
+	if (!memcmp(EP_STRING, (void *)EP_OFFSET, strlen(EP_STRING)))
+		return;
+
+	sclp_early_printk("Linux kernel boot failure: An attempt to boot a vmlinux ELF image failed.\n");
+	sclp_early_printk("This image does not contain all parts necessary for starting up. Use\n");
+	sclp_early_printk("bzImage or arch/s390/boot/compressed/vmlinux instead.\n");
+	disabled_wait();
+}
+
+void __init startup_init(void)
+{
+	reset_tod_clock();
+	check_image_bootable();
+	time_early_init();
+	init_kernel_storage_key();
+	lockdep_off();
+	setup_lowcore_early();
+	setup_facility_list();
+	detect_machine_type();
+	setup_arch_string();
+	setup_boot_command_line();
+	detect_diag9c();
+	detect_machine_facilities();
+	save_vector_registers();
+	setup_topology();
+	sclp_early_detect();
+	setup_control_registers();
+	setup_access_registers();
+	lockdep_on();
+}