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Diffstat (limited to 'arch/s390/kernel/nmi.c')
-rw-r--r--arch/s390/kernel/nmi.c181
1 files changed, 90 insertions, 91 deletions
diff --git a/arch/s390/kernel/nmi.c b/arch/s390/kernel/nmi.c
index 31cb9b00a36b..5dbf274719a9 100644
--- a/arch/s390/kernel/nmi.c
+++ b/arch/s390/kernel/nmi.c
@@ -19,7 +19,7 @@
#include <linux/time.h>
#include <linux/module.h>
#include <linux/sched/signal.h>
-
+#include <linux/kvm_host.h>
#include <linux/export.h>
#include <asm/lowcore.h>
#include <asm/smp.h>
@@ -31,8 +31,7 @@
#include <asm/ctl_reg.h>
#include <asm/asm-offsets.h>
#include <asm/pai.h>
-
-#include <linux/kvm_host.h>
+#include <asm/vx-insn.h>
struct mcck_struct {
unsigned int kill_task : 1;
@@ -43,21 +42,12 @@ struct mcck_struct {
};
static DEFINE_PER_CPU(struct mcck_struct, cpu_mcck);
-static struct kmem_cache *mcesa_cache;
-static unsigned long mcesa_origin_lc;
static inline int nmi_needs_mcesa(void)
{
return MACHINE_HAS_VX || MACHINE_HAS_GS;
}
-static inline unsigned long nmi_get_mcesa_size(void)
-{
- if (MACHINE_HAS_GS)
- return MCESA_MAX_SIZE;
- return MCESA_MIN_SIZE;
-}
-
/*
* The initial machine check extended save area for the boot CPU.
* It will be replaced on the boot CPU reinit with an allocated
@@ -75,36 +65,23 @@ void __init nmi_alloc_mcesa_early(u64 *mcesad)
*mcesad |= ilog2(MCESA_MAX_SIZE);
}
-static void __init nmi_alloc_cache(void)
+int nmi_alloc_mcesa(u64 *mcesad)
{
unsigned long size;
-
- if (!nmi_needs_mcesa())
- return;
- size = nmi_get_mcesa_size();
- if (size > MCESA_MIN_SIZE)
- mcesa_origin_lc = ilog2(size);
- /* create slab cache for the machine-check-extended-save-areas */
- mcesa_cache = kmem_cache_create("nmi_save_areas", size, size, 0, NULL);
- if (!mcesa_cache)
- panic("Couldn't create nmi save area cache");
-}
-
-int __ref nmi_alloc_mcesa(u64 *mcesad)
-{
- unsigned long origin;
+ void *origin;
*mcesad = 0;
if (!nmi_needs_mcesa())
return 0;
- if (!mcesa_cache)
- nmi_alloc_cache();
- origin = (unsigned long) kmem_cache_alloc(mcesa_cache, GFP_KERNEL);
+ size = MACHINE_HAS_GS ? MCESA_MAX_SIZE : MCESA_MIN_SIZE;
+ origin = kmalloc(size, GFP_KERNEL);
if (!origin)
return -ENOMEM;
/* The pointer is stored with mcesa_bits ORed in */
- kmemleak_not_leak((void *) origin);
- *mcesad = __pa(origin) | mcesa_origin_lc;
+ kmemleak_not_leak(origin);
+ *mcesad = __pa(origin);
+ if (MACHINE_HAS_GS)
+ *mcesad |= ilog2(MCESA_MAX_SIZE);
return 0;
}
@@ -112,12 +89,64 @@ void nmi_free_mcesa(u64 *mcesad)
{
if (!nmi_needs_mcesa())
return;
- kmem_cache_free(mcesa_cache, __va(*mcesad & MCESA_ORIGIN_MASK));
+ kfree(__va(*mcesad & MCESA_ORIGIN_MASK));
+}
+
+static __always_inline char *nmi_puts(char *dest, const char *src)
+{
+ while (*src)
+ *dest++ = *src++;
+ *dest = 0;
+ return dest;
+}
+
+static __always_inline char *u64_to_hex(char *dest, u64 val)
+{
+ int i, num;
+
+ for (i = 1; i <= 16; i++) {
+ num = (val >> (64 - 4 * i)) & 0xf;
+ if (num >= 10)
+ *dest++ = 'A' + num - 10;
+ else
+ *dest++ = '0' + num;
+ }
+ *dest = 0;
+ return dest;
}
static notrace void s390_handle_damage(void)
{
+ union ctlreg0 cr0, cr0_new;
+ char message[100];
+ psw_t psw_save;
+ char *ptr;
+
smp_emergency_stop();
+ diag_amode31_ops.diag308_reset();
+ ptr = nmi_puts(message, "System stopped due to unrecoverable machine check, code: 0x");
+ u64_to_hex(ptr, S390_lowcore.mcck_interruption_code);
+
+ /*
+ * Disable low address protection and make machine check new PSW a
+ * disabled wait PSW. Any additional machine check cannot be handled.
+ */
+ __ctl_store(cr0.val, 0, 0);
+ cr0_new = cr0;
+ cr0_new.lap = 0;
+ __ctl_load(cr0_new.val, 0, 0);
+ psw_save = S390_lowcore.mcck_new_psw;
+ psw_bits(S390_lowcore.mcck_new_psw).io = 0;
+ psw_bits(S390_lowcore.mcck_new_psw).ext = 0;
+ psw_bits(S390_lowcore.mcck_new_psw).wait = 1;
+ sclp_emergency_printk(message);
+
+ /*
+ * Restore machine check new PSW and control register 0 to original
+ * values. This makes possible system dump analysis easier.
+ */
+ S390_lowcore.mcck_new_psw = psw_save;
+ __ctl_load(cr0.val, 0, 0);
disabled_wait();
while (1);
}
@@ -181,10 +210,10 @@ void noinstr s390_handle_mcck(struct pt_regs *regs)
trace_hardirqs_on();
}
/*
- * returns 0 if all required registers are available
+ * returns 0 if register contents could be validated
* returns 1 otherwise
*/
-static int notrace s390_validate_registers(union mci mci, int umode)
+static int notrace s390_validate_registers(union mci mci)
{
struct mcesa *mcesa;
void *fpt_save_area;
@@ -195,45 +224,15 @@ static int notrace s390_validate_registers(union mci mci, int umode)
kill_task = 0;
zero = 0;
- if (!mci.gr) {
- /*
- * General purpose registers couldn't be restored and have
- * unknown contents. Stop system or terminate process.
- */
- if (!umode)
- s390_handle_damage();
+ if (!mci.gr || !mci.fp)
kill_task = 1;
- }
- if (!mci.fp) {
- /*
- * Floating point registers can't be restored. If the
- * kernel currently uses floating point registers the
- * system is stopped. If the process has its floating
- * pointer registers loaded it is terminated.
- */
- if (S390_lowcore.fpu_flags & KERNEL_VXR_V0V7)
- s390_handle_damage();
- if (!test_cpu_flag(CIF_FPU))
- kill_task = 1;
- }
fpt_save_area = &S390_lowcore.floating_pt_save_area;
if (!mci.fc) {
- /*
- * Floating point control register can't be restored.
- * If the kernel currently uses the floating pointer
- * registers and needs the FPC register the system is
- * stopped. If the process has its floating pointer
- * registers loaded it is terminated. Otherwise the
- * FPC is just validated.
- */
- if (S390_lowcore.fpu_flags & KERNEL_FPC)
- s390_handle_damage();
+ kill_task = 1;
asm volatile(
" lfpc %0\n"
:
: "Q" (zero));
- if (!test_cpu_flag(CIF_FPU))
- kill_task = 1;
} else {
asm volatile(
" lfpc %0\n"
@@ -275,26 +274,15 @@ static int notrace s390_validate_registers(union mci mci, int umode)
* appropriate actions. The host vector or FPU values have been
* saved by KVM and will be restored by KVM.
*/
- if (!mci.vr && !test_cpu_flag(CIF_MCCK_GUEST)) {
- /*
- * Vector registers can't be restored. If the kernel
- * currently uses vector registers the system is
- * stopped. If the process has its vector registers
- * loaded it is terminated. Otherwise just validate
- * the registers.
- */
- if (S390_lowcore.fpu_flags & KERNEL_VXR)
- s390_handle_damage();
- if (!test_cpu_flag(CIF_FPU))
- kill_task = 1;
- }
+ if (!mci.vr && !test_cpu_flag(CIF_MCCK_GUEST))
+ kill_task = 1;
cr0.val = S390_lowcore.cregs_save_area[0];
cr0.afp = cr0.vx = 1;
__ctl_load(cr0.val, 0, 0);
asm volatile(
" la 1,%0\n"
- " .word 0xe70f,0x1000,0x0036\n" /* vlm 0,15,0(1) */
- " .word 0xe70f,0x1100,0x0c36\n" /* vlm 16,31,256(1) */
+ " VLM 0,15,0,1\n"
+ " VLM 16,31,256,1\n"
:
: "Q" (*(struct vx_array *)mcesa->vector_save_area)
: "1");
@@ -306,13 +294,8 @@ static int notrace s390_validate_registers(union mci mci, int umode)
:
: "a" (&S390_lowcore.access_regs_save_area)
: "memory");
- if (!mci.ar) {
- /*
- * Access registers have unknown contents.
- * Terminating task.
- */
+ if (!mci.ar)
kill_task = 1;
- }
/* Validate guarded storage registers */
cr2.val = S390_lowcore.cregs_save_area[2];
if (cr2.gse) {
@@ -451,7 +434,9 @@ int notrace s390_do_machine_check(struct pt_regs *regs)
s390_handle_damage();
}
}
- if (s390_validate_registers(mci, user_mode(regs))) {
+ if (s390_validate_registers(mci)) {
+ if (!user_mode(regs))
+ s390_handle_damage();
/*
* Couldn't restore all register contents for the
* user space process -> mark task for termination.
@@ -480,7 +465,21 @@ int notrace s390_do_machine_check(struct pt_regs *regs)
mcck->stp_queue |= stp_island_check();
mcck_pending = 1;
}
-
+ /*
+ * Reinject storage related machine checks into the guest if they
+ * happen when the guest is running.
+ */
+ if (!test_cpu_flag(CIF_MCCK_GUEST)) {
+ /* Storage error uncorrected */
+ if (mci.se)
+ s390_handle_damage();
+ /* Storage key-error uncorrected */
+ if (mci.ke)
+ s390_handle_damage();
+ /* Storage degradation */
+ if (mci.ds && mci.fa)
+ s390_handle_damage();
+ }
if (mci.cp) {
/* Channel report word pending */
mcck->channel_report = 1;
generated by cgit v1.2.3 (git 2.39.1) at 2024-06-21 07:54:06 +0000