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authorMartin Schwidefsky <schwidefsky@de.ibm.com>2016-01-26 14:10:34 +0100
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2017-03-22 08:14:25 +0100
commit916cda1aa1b412d7cf2991c3af7479544942d121 (patch)
tree51e373acacf962c1635899f1567484be0baed745 /arch/s390/kernel/smp.c
parent093b995e3b55a0ae0670226ddfcb05bfbf0099ae (diff)
s390: add a system call for guarded storage
This adds a new system call to enable the use of guarded storage for user space processes. The system call takes two arguments, a command and pointer to a guarded storage control block: s390_guarded_storage(int command, struct gs_cb *gs_cb); The second argument is relevant only for the GS_SET_BC_CB command. The commands in detail: 0 - GS_ENABLE Enable the guarded storage facility for the current task. The initial content of the guarded storage control block will be all zeros. After the enablement the user space code can use load-guarded-storage-controls instruction (LGSC) to load an arbitrary control block. While a task is enabled the kernel will save and restore the current content of the guarded storage registers on context switch. 1 - GS_DISABLE Disables the use of the guarded storage facility for the current task. The kernel will cease to save and restore the content of the guarded storage registers, the task specific content of these registers is lost. 2 - GS_SET_BC_CB Set a broadcast guarded storage control block. This is called per thread and stores a specific guarded storage control block in the task struct of the current task. This control block will be used for the broadcast event GS_BROADCAST. 3 - GS_CLEAR_BC_CB Clears the broadcast guarded storage control block. The guarded- storage control block is removed from the task struct that was established by GS_SET_BC_CB. 4 - GS_BROADCAST Sends a broadcast to all thread siblings of the current task. Every sibling that has established a broadcast guarded storage control block will load this control block and will be enabled for guarded storage. The broadcast guarded storage control block is used up, a second broadcast without a refresh of the stored control block with GS_SET_BC_CB will not have any effect. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/kernel/smp.c')
-rw-r--r--arch/s390/kernel/smp.c43
1 files changed, 38 insertions, 5 deletions
diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
index 47a973b5b4f1..286bcee800f4 100644
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -51,6 +51,7 @@
#include <asm/os_info.h>
#include <asm/sigp.h>
#include <asm/idle.h>
+#include <asm/nmi.h>
#include "entry.h"
enum {
@@ -78,6 +79,8 @@ struct pcpu {
static u8 boot_core_type;
static struct pcpu pcpu_devices[NR_CPUS];
+static struct kmem_cache *pcpu_mcesa_cache;
+
unsigned int smp_cpu_mt_shift;
EXPORT_SYMBOL(smp_cpu_mt_shift);
@@ -188,8 +191,10 @@ static void pcpu_ec_call(struct pcpu *pcpu, int ec_bit)
static int pcpu_alloc_lowcore(struct pcpu *pcpu, int cpu)
{
unsigned long async_stack, panic_stack;
+ unsigned long mcesa_origin, mcesa_bits;
struct lowcore *lc;
+ mcesa_origin = mcesa_bits = 0;
if (pcpu != &pcpu_devices[0]) {
pcpu->lowcore = (struct lowcore *)
__get_free_pages(GFP_KERNEL | GFP_DMA, LC_ORDER);
@@ -197,20 +202,27 @@ static int pcpu_alloc_lowcore(struct pcpu *pcpu, int cpu)
panic_stack = __get_free_page(GFP_KERNEL);
if (!pcpu->lowcore || !panic_stack || !async_stack)
goto out;
+ if (MACHINE_HAS_VX || MACHINE_HAS_GS) {
+ mcesa_origin = (unsigned long)
+ kmem_cache_alloc(pcpu_mcesa_cache, GFP_KERNEL);
+ if (!mcesa_origin)
+ goto out;
+ mcesa_bits = MACHINE_HAS_GS ? 11 : 0;
+ }
} else {
async_stack = pcpu->lowcore->async_stack - ASYNC_FRAME_OFFSET;
panic_stack = pcpu->lowcore->panic_stack - PANIC_FRAME_OFFSET;
+ mcesa_origin = pcpu->lowcore->mcesad & MCESA_ORIGIN_MASK;
+ mcesa_bits = pcpu->lowcore->mcesad & MCESA_LC_MASK;
}
lc = pcpu->lowcore;
memcpy(lc, &S390_lowcore, 512);
memset((char *) lc + 512, 0, sizeof(*lc) - 512);
lc->async_stack = async_stack + ASYNC_FRAME_OFFSET;
lc->panic_stack = panic_stack + PANIC_FRAME_OFFSET;
+ lc->mcesad = mcesa_origin | mcesa_bits;
lc->cpu_nr = cpu;
lc->spinlock_lockval = arch_spin_lockval(cpu);
- if (MACHINE_HAS_VX)
- lc->vector_save_area_addr =
- (unsigned long) &lc->vector_save_area;
if (vdso_alloc_per_cpu(lc))
goto out;
lowcore_ptr[cpu] = lc;
@@ -218,6 +230,9 @@ static int pcpu_alloc_lowcore(struct pcpu *pcpu, int cpu)
return 0;
out:
if (pcpu != &pcpu_devices[0]) {
+ if (mcesa_origin)
+ kmem_cache_free(pcpu_mcesa_cache,
+ (void *) mcesa_origin);
free_page(panic_stack);
free_pages(async_stack, ASYNC_ORDER);
free_pages((unsigned long) pcpu->lowcore, LC_ORDER);
@@ -229,11 +244,17 @@ out:
static void pcpu_free_lowcore(struct pcpu *pcpu)
{
+ unsigned long mcesa_origin;
+
pcpu_sigp_retry(pcpu, SIGP_SET_PREFIX, 0);
lowcore_ptr[pcpu - pcpu_devices] = NULL;
vdso_free_per_cpu(pcpu->lowcore);
if (pcpu == &pcpu_devices[0])
return;
+ if (MACHINE_HAS_VX || MACHINE_HAS_GS) {
+ mcesa_origin = pcpu->lowcore->mcesad & MCESA_ORIGIN_MASK;
+ kmem_cache_free(pcpu_mcesa_cache, (void *) mcesa_origin);
+ }
free_page(pcpu->lowcore->panic_stack-PANIC_FRAME_OFFSET);
free_pages(pcpu->lowcore->async_stack-ASYNC_FRAME_OFFSET, ASYNC_ORDER);
free_pages((unsigned long) pcpu->lowcore, LC_ORDER);
@@ -550,9 +571,11 @@ int smp_store_status(int cpu)
if (__pcpu_sigp_relax(pcpu->address, SIGP_STORE_STATUS_AT_ADDRESS,
pa) != SIGP_CC_ORDER_CODE_ACCEPTED)
return -EIO;
- if (!MACHINE_HAS_VX)
+ if (!MACHINE_HAS_VX && !MACHINE_HAS_GS)
return 0;
- pa = __pa(pcpu->lowcore->vector_save_area_addr);
+ pa = __pa(pcpu->lowcore->mcesad & MCESA_ORIGIN_MASK);
+ if (MACHINE_HAS_GS)
+ pa |= pcpu->lowcore->mcesad & MCESA_LC_MASK;
if (__pcpu_sigp_relax(pcpu->address, SIGP_STORE_ADDITIONAL_STATUS,
pa) != SIGP_CC_ORDER_CODE_ACCEPTED)
return -EIO;
@@ -897,12 +920,22 @@ void __init smp_fill_possible_mask(void)
void __init smp_prepare_cpus(unsigned int max_cpus)
{
+ unsigned long size;
+
/* request the 0x1201 emergency signal external interrupt */
if (register_external_irq(EXT_IRQ_EMERGENCY_SIG, do_ext_call_interrupt))
panic("Couldn't request external interrupt 0x1201");
/* request the 0x1202 external call external interrupt */
if (register_external_irq(EXT_IRQ_EXTERNAL_CALL, do_ext_call_interrupt))
panic("Couldn't request external interrupt 0x1202");
+ /* create slab cache for the machine-check-extended-save-areas */
+ if (MACHINE_HAS_VX || MACHINE_HAS_GS) {
+ size = 1UL << (MACHINE_HAS_GS ? 11 : 10);
+ pcpu_mcesa_cache = kmem_cache_create("nmi_save_areas",
+ size, size, 0, NULL);
+ if (!pcpu_mcesa_cache)
+ panic("Couldn't create nmi save area cache");
+ }
}
void __init smp_prepare_boot_cpu(void)