#include <asm/sclp.h>
#include <asm/diag.h>
#include <asm/uv.h>
+#include <asm/abs_lowcore.h>
#include "decompressor.h"
#include "boot.h"
#include "uv.h"
unsigned long __bootdata_preserved(__kaslr_offset);
+unsigned long __bootdata_preserved(__abs_lowcore);
unsigned long __bootdata(__amode31_base);
unsigned long __bootdata_preserved(VMALLOC_START);
unsigned long __bootdata_preserved(VMALLOC_END);
/* force vmalloc and modules below kasan shadow */
vmax = min(vmax, KASAN_SHADOW_START);
#endif
- MODULES_END = vmax;
+ __abs_lowcore = round_down(vmax - ABS_LOWCORE_MAP_SIZE, sizeof(struct lowcore));
+ MODULES_END = round_down(__abs_lowcore, _SEGMENT_SIZE);
MODULES_VADDR = MODULES_END - MODULES_LEN;
VMALLOC_END = MODULES_VADDR;
--- /dev/null
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_S390_ABS_LOWCORE_H
+#define _ASM_S390_ABS_LOWCORE_H
+
+#include <asm/lowcore.h>
+
+#define ABS_LOWCORE_MAP_SIZE (NR_CPUS * sizeof(struct lowcore))
+
+extern unsigned long __abs_lowcore;
+extern bool abs_lowcore_mapped;
+
+struct lowcore *get_abs_lowcore(unsigned long *flags);
+void put_abs_lowcore(struct lowcore *lc, unsigned long flags);
+int abs_lowcore_map(int cpu, struct lowcore *lc);
+void abs_lowcore_unmap(int cpu);
+
+#endif /* _ASM_ABS_S390_LOWCORE_H */
extern int vmem_add_mapping(unsigned long start, unsigned long size);
extern void vmem_remove_mapping(unsigned long start, unsigned long size);
+extern int vmem_map_4k_page(unsigned long addr, unsigned long phys, pgprot_t prot);
+extern void vmem_unmap_4k_page(unsigned long addr);
extern int s390_enable_sie(void);
extern int s390_enable_skey(void);
extern void s390_reset_cmma(struct mm_struct *mm);
#define ARCH_LOW_ADDRESS_LIMIT 0x7fffffffUL
extern int memcpy_real(void *, unsigned long, size_t);
-extern void memcpy_absolute(void *, void *, size_t);
-
-#define put_abs_lowcore(member, x) do { \
- unsigned long __abs_address = offsetof(struct lowcore, member); \
- __typeof__(((struct lowcore *)0)->member) __tmp = (x); \
- \
- memcpy_absolute(__va(__abs_address), &__tmp, sizeof(__tmp)); \
-} while (0)
-
-#define get_abs_lowcore(x, member) do { \
- unsigned long __abs_address = offsetof(struct lowcore, member); \
- __typeof__(((struct lowcore *)0)->member) *__ptr = &(x); \
- \
- memcpy_absolute(__ptr, __va(__abs_address), sizeof(*__ptr)); \
-} while (0)
extern int s390_isolate_bp(void);
extern int s390_isolate_bp_guest(void);
obj-y += runtime_instr.o cache.o fpu.o dumpstack.o guarded_storage.o sthyi.o
obj-y += entry.o reipl.o relocate_kernel.o kdebugfs.o alternative.o
obj-y += nospec-branch.o ipl_vmparm.o machine_kexec_reloc.o unwind_bc.o
-obj-y += smp.o text_amode31.o stacktrace.o
+obj-y += smp.o text_amode31.o stacktrace.o abs_lowcore.o
extra-y += head64.o vmlinux.lds
--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/pgtable.h>
+#include <asm/pgtable.h>
+#include <asm/abs_lowcore.h>
+
+#define ABS_LOWCORE_UNMAPPED 1
+#define ABS_LOWCORE_LAP_ON 2
+#define ABS_LOWCORE_IRQS_ON 4
+
+unsigned long __bootdata_preserved(__abs_lowcore);
+bool __ro_after_init abs_lowcore_mapped;
+
+int abs_lowcore_map(int cpu, struct lowcore *lc)
+{
+ unsigned long addr = __abs_lowcore + (cpu * sizeof(struct lowcore));
+ unsigned long phys = __pa(lc);
+ int rc, i;
+
+ for (i = 0; i < LC_PAGES; i++) {
+ rc = vmem_map_4k_page(addr, phys, PAGE_KERNEL);
+ if (rc) {
+ for (--i; i >= 0; i--) {
+ addr -= PAGE_SIZE;
+ vmem_unmap_4k_page(addr);
+ }
+ return rc;
+ }
+ addr += PAGE_SIZE;
+ phys += PAGE_SIZE;
+ }
+ return 0;
+}
+
+void abs_lowcore_unmap(int cpu)
+{
+ unsigned long addr = __abs_lowcore + (cpu * sizeof(struct lowcore));
+ int i;
+
+ for (i = 0; i < LC_PAGES; i++) {
+ vmem_unmap_4k_page(addr);
+ addr += PAGE_SIZE;
+ }
+}
+
+struct lowcore *get_abs_lowcore(unsigned long *flags)
+{
+ unsigned long irq_flags;
+ union ctlreg0 cr0;
+ int cpu;
+
+ *flags = 0;
+ cpu = get_cpu();
+ if (abs_lowcore_mapped) {
+ return ((struct lowcore *)__abs_lowcore) + cpu;
+ } else {
+ if (cpu != 0)
+ panic("Invalid unmapped absolute lowcore access\n");
+ local_irq_save(irq_flags);
+ if (!irqs_disabled_flags(irq_flags))
+ *flags |= ABS_LOWCORE_IRQS_ON;
+ __ctl_store(cr0.val, 0, 0);
+ if (cr0.lap) {
+ *flags |= ABS_LOWCORE_LAP_ON;
+ __ctl_clear_bit(0, 28);
+ }
+ *flags |= ABS_LOWCORE_UNMAPPED;
+ return lowcore_ptr[0];
+ }
+}
+
+void put_abs_lowcore(struct lowcore *lc, unsigned long flags)
+{
+ if (abs_lowcore_mapped) {
+ if (flags)
+ panic("Invalid mapped absolute lowcore release\n");
+ } else {
+ if (smp_processor_id() != 0)
+ panic("Invalid mapped absolute lowcore access\n");
+ if (!(flags & ABS_LOWCORE_UNMAPPED))
+ panic("Invalid unmapped absolute lowcore release\n");
+ if (flags & ABS_LOWCORE_LAP_ON)
+ __ctl_set_bit(0, 28);
+ if (flags & ABS_LOWCORE_IRQS_ON)
+ local_irq_enable();
+ }
+ put_cpu();
+}
#include <asm/sclp.h>
#include <asm/checksum.h>
#include <asm/debug.h>
+#include <asm/abs_lowcore.h>
#include <asm/os_info.h>
#include <asm/sections.h>
#include <asm/boot_data.h>
static void dump_reipl_run(struct shutdown_trigger *trigger)
{
unsigned long ipib = (unsigned long) reipl_block_actual;
+ struct lowcore *abs_lc;
+ unsigned long flags;
unsigned int csum;
csum = (__force unsigned int)
csum_partial(reipl_block_actual, reipl_block_actual->hdr.len, 0);
- put_abs_lowcore(ipib, ipib);
- put_abs_lowcore(ipib_checksum, csum);
+ abs_lc = get_abs_lowcore(&flags);
+ abs_lc->ipib = ipib;
+ abs_lc->ipib_checksum = csum;
+ put_abs_lowcore(abs_lc, flags);
dump_run(trigger);
}
#include <asm/elf.h>
#include <asm/asm-offsets.h>
#include <asm/cacheflush.h>
+#include <asm/abs_lowcore.h>
#include <asm/os_info.h>
#include <asm/set_memory.h>
#include <asm/stacktrace.h>
void arch_crash_save_vmcoreinfo(void)
{
+ struct lowcore *abs_lc;
+ unsigned long flags;
+
VMCOREINFO_SYMBOL(lowcore_ptr);
VMCOREINFO_SYMBOL(high_memory);
VMCOREINFO_LENGTH(lowcore_ptr, NR_CPUS);
vmcoreinfo_append_str("SAMODE31=%lx\n", __samode31);
vmcoreinfo_append_str("EAMODE31=%lx\n", __eamode31);
vmcoreinfo_append_str("KERNELOFFSET=%lx\n", kaslr_offset());
- put_abs_lowcore(vmcore_info, paddr_vmcoreinfo_note());
+ abs_lc = get_abs_lowcore(&flags);
+ abs_lc->vmcore_info = paddr_vmcoreinfo_note();
+ put_abs_lowcore(abs_lc, flags);
}
void machine_shutdown(void)
#include <linux/kernel.h>
#include <linux/slab.h>
#include <asm/checksum.h>
-#include <asm/lowcore.h>
+#include <asm/abs_lowcore.h>
#include <asm/os_info.h>
#include <asm/asm-offsets.h>
*/
void __init os_info_init(void)
{
- void *ptr = &os_info;
+ struct lowcore *abs_lc;
+ unsigned long flags;
os_info.version_major = OS_INFO_VERSION_MAJOR;
os_info.version_minor = OS_INFO_VERSION_MINOR;
os_info.magic = OS_INFO_MAGIC;
os_info.csum = os_info_csum(&os_info);
- put_abs_lowcore(os_info, __pa(ptr));
+ abs_lc = get_abs_lowcore(&flags);
+ abs_lc->os_info = __pa(&os_info);
+ put_abs_lowcore(abs_lc, flags);
}
#ifdef CONFIG_CRASH_DUMP
#include <asm/smp.h>
#include <asm/mmu_context.h>
#include <asm/cpcmd.h>
-#include <asm/lowcore.h>
+#include <asm/abs_lowcore.h>
#include <asm/nmi.h>
#include <asm/irq.h>
#include <asm/page.h>
static void __init setup_lowcore_dat_off(void)
{
unsigned long int_psw_mask = PSW_KERNEL_BITS;
+ struct lowcore *abs_lc, *lc;
unsigned long mcck_stack;
- struct lowcore *lc;
+ unsigned long flags;
if (IS_ENABLED(CONFIG_KASAN))
int_psw_mask |= PSW_MASK_DAT;
lc->restart_data = 0;
lc->restart_source = -1U;
- put_abs_lowcore(restart_stack, lc->restart_stack);
- put_abs_lowcore(restart_fn, lc->restart_fn);
- put_abs_lowcore(restart_data, lc->restart_data);
- put_abs_lowcore(restart_source, lc->restart_source);
- put_abs_lowcore(restart_psw, lc->restart_psw);
+ abs_lc = get_abs_lowcore(&flags);
+ abs_lc->restart_stack = lc->restart_stack;
+ abs_lc->restart_fn = lc->restart_fn;
+ abs_lc->restart_data = lc->restart_data;
+ abs_lc->restart_source = lc->restart_source;
+ abs_lc->restart_psw = lc->restart_psw;
+ put_abs_lowcore(abs_lc, flags);
mcck_stack = (unsigned long)memblock_alloc(THREAD_SIZE, THREAD_SIZE);
if (!mcck_stack)
static void __init setup_lowcore_dat_on(void)
{
- struct lowcore *lc = lowcore_ptr[0];
- int cr;
+ struct lowcore *abs_lc;
+ unsigned long flags;
__ctl_clear_bit(0, 28);
S390_lowcore.external_new_psw.mask |= PSW_MASK_DAT;
S390_lowcore.io_new_psw.mask |= PSW_MASK_DAT;
__ctl_set_bit(0, 28);
__ctl_store(S390_lowcore.cregs_save_area, 0, 15);
- put_abs_lowcore(restart_flags, RESTART_FLAG_CTLREGS);
- put_abs_lowcore(program_new_psw, lc->program_new_psw);
- for (cr = 0; cr < ARRAY_SIZE(lc->cregs_save_area); cr++)
- put_abs_lowcore(cregs_save_area[cr], lc->cregs_save_area[cr]);
+ abs_lc = get_abs_lowcore(&flags);
+ abs_lc->restart_flags = RESTART_FLAG_CTLREGS;
+ abs_lc->program_new_psw = S390_lowcore.program_new_psw;
+ memcpy(abs_lc->cregs_save_area, S390_lowcore.cregs_save_area,
+ sizeof(abs_lc->cregs_save_area));
+ put_abs_lowcore(abs_lc, flags);
+ if (abs_lowcore_map(0, lowcore_ptr[0]))
+ panic("Couldn't setup absolute lowcore");
+ abs_lowcore_mapped = true;
}
static struct resource code_resource = {
#include <asm/irq.h>
#include <asm/tlbflush.h>
#include <asm/vtimer.h>
-#include <asm/lowcore.h>
+#include <asm/abs_lowcore.h>
#include <asm/sclp.h>
#include <asm/debug.h>
#include <asm/os_info.h>
lc->preempt_count = PREEMPT_DISABLED;
if (nmi_alloc_mcesa(&lc->mcesad))
goto out;
+ if (abs_lowcore_map(cpu, lc))
+ goto out_mcesa;
lowcore_ptr[cpu] = lc;
pcpu_sigp_retry(pcpu, SIGP_SET_PREFIX, __pa(lc));
return 0;
+out_mcesa:
+ nmi_free_mcesa(&lc->mcesad);
out:
stack_free(mcck_stack);
stack_free(async_stack);
mcck_stack = lc->mcck_stack - STACK_INIT_OFFSET;
pcpu_sigp_retry(pcpu, SIGP_SET_PREFIX, 0);
lowcore_ptr[cpu] = NULL;
+ abs_lowcore_unmap(cpu);
nmi_free_mcesa(&lc->mcesad);
stack_free(async_stack);
stack_free(mcck_stack);
pcpu_delegate_fn *func,
void *data, unsigned long stack)
{
- struct lowcore *lc = lowcore_ptr[pcpu - pcpu_devices];
- unsigned int source_cpu = stap();
+ struct lowcore *lc, *abs_lc;
+ unsigned int source_cpu;
+ unsigned long flags;
+ lc = lowcore_ptr[pcpu - pcpu_devices];
+ source_cpu = stap();
__load_psw_mask(PSW_KERNEL_BITS | PSW_MASK_DAT);
if (pcpu->address == source_cpu) {
call_on_stack(2, stack, void, __pcpu_delegate,
lc->restart_data = (unsigned long)data;
lc->restart_source = source_cpu;
} else {
- put_abs_lowcore(restart_stack, stack);
- put_abs_lowcore(restart_fn, (unsigned long)func);
- put_abs_lowcore(restart_data, (unsigned long)data);
- put_abs_lowcore(restart_source, source_cpu);
+ abs_lc = get_abs_lowcore(&flags);
+ abs_lc->restart_stack = stack;
+ abs_lc->restart_fn = (unsigned long)func;
+ abs_lc->restart_data = (unsigned long)data;
+ abs_lc->restart_source = source_cpu;
+ put_abs_lowcore(abs_lc, flags);
}
__bpon();
asm volatile(
void smp_ctl_set_clear_bit(int cr, int bit, bool set)
{
struct ec_creg_mask_parms parms = { .cr = cr, };
+ struct lowcore *abs_lc;
+ unsigned long flags;
u64 ctlreg;
if (set) {
parms.andval = ~(1UL << bit);
}
spin_lock(&ctl_lock);
- get_abs_lowcore(ctlreg, cregs_save_area[cr]);
+ abs_lc = get_abs_lowcore(&flags);
+ ctlreg = abs_lc->cregs_save_area[cr];
ctlreg = (ctlreg & parms.andval) | parms.orval;
- put_abs_lowcore(cregs_save_area[cr], ctlreg);
+ abs_lc->cregs_save_area[cr] = ctlreg;
+ put_abs_lowcore(abs_lc, flags);
spin_unlock(&ctl_lock);
on_each_cpu(smp_ctl_bit_callback, &parms, 1);
}
__ctl_clear_bit(0, 28); /* disable lowcore protection */
S390_lowcore.mcesad = mcesad;
__ctl_load(cr0, 0, 0);
+ if (abs_lowcore_map(0, lc))
+ panic("Couldn't remap absolute lowcore");
lowcore_ptr[0] = lc;
local_mcck_enable();
local_irq_restore(flags);
#include <asm/kfence.h>
#include <asm/ptdump.h>
#include <asm/dma.h>
-#include <asm/lowcore.h>
+#include <asm/abs_lowcore.h>
#include <asm/tlb.h>
#include <asm/tlbflush.h>
#include <asm/sections.h>
#include <asm/asm-extable.h>
#include <asm/ctl_reg.h>
#include <asm/io.h>
+#include <asm/abs_lowcore.h>
#include <asm/stacktrace.h>
static notrace long s390_kernel_write_odd(void *dst, const void *src, size_t size)
}
/*
- * Copy memory in absolute mode (kernel to kernel)
+ * Find CPU that owns swapped prefix page
*/
-void memcpy_absolute(void *dest, void *src, size_t count)
-{
- unsigned long cr0, flags, prefix;
-
- flags = arch_local_irq_save();
- __ctl_store(cr0, 0, 0);
- __ctl_clear_bit(0, 28); /* disable lowcore protection */
- prefix = store_prefix();
- if (prefix) {
- local_mcck_disable();
- set_prefix(0);
- memcpy(dest, src, count);
- set_prefix(prefix);
- local_mcck_enable();
- } else {
- memcpy(dest, src, count);
- }
- __ctl_load(cr0, 0, 0);
- arch_local_irq_restore(flags);
-}
-
-/*
- * Check if physical address is within prefix or zero page
- */
-static int is_swapped(phys_addr_t addr)
+static int get_swapped_owner(phys_addr_t addr)
{
phys_addr_t lc;
int cpu;
- if (addr < sizeof(struct lowcore))
- return 1;
for_each_online_cpu(cpu) {
lc = virt_to_phys(lowcore_ptr[cpu]);
if (addr > lc + sizeof(struct lowcore) - 1 || addr < lc)
continue;
- return 1;
+ return cpu;
}
- return 0;
+ return -1;
}
/*
{
void *ptr = phys_to_virt(addr);
void *bounce = ptr;
+ struct lowcore *abs_lc;
+ unsigned long flags;
unsigned long size;
+ int this_cpu, cpu;
cpus_read_lock();
- preempt_disable();
- if (is_swapped(addr)) {
- size = PAGE_SIZE - (addr & ~PAGE_MASK);
- bounce = (void *) __get_free_page(GFP_ATOMIC);
- if (bounce)
- memcpy_absolute(bounce, ptr, size);
+ this_cpu = get_cpu();
+ if (addr >= sizeof(struct lowcore)) {
+ cpu = get_swapped_owner(addr);
+ if (cpu < 0)
+ goto out;
+ }
+ bounce = (void *)__get_free_page(GFP_ATOMIC);
+ if (!bounce)
+ goto out;
+ size = PAGE_SIZE - (addr & ~PAGE_MASK);
+ if (addr < sizeof(struct lowcore)) {
+ abs_lc = get_abs_lowcore(&flags);
+ ptr = (void *)abs_lc + addr;
+ memcpy(bounce, ptr, size);
+ put_abs_lowcore(abs_lc, flags);
+ } else if (cpu == this_cpu) {
+ ptr = (void *)(addr - virt_to_phys(lowcore_ptr[cpu]));
+ memcpy(bounce, ptr, size);
+ } else {
+ memcpy(bounce, ptr, size);
}
- preempt_enable();
+out:
+ put_cpu();
cpus_read_unlock();
return bounce;
}
return ret;
}
+/*
+ * Allocate new or return existing page-table entry, but do not map it
+ * to any physical address. If missing, allocate segment- and region-
+ * table entries along. Meeting a large segment- or region-table entry
+ * while traversing is an error, since the function is expected to be
+ * called against virtual regions reserverd for 4KB mappings only.
+ */
+static pte_t *vmem_get_alloc_pte(unsigned long addr)
+{
+ pte_t *ptep = NULL;
+ pgd_t *pgd;
+ p4d_t *p4d;
+ pud_t *pud;
+ pmd_t *pmd;
+ pte_t *pte;
+
+ pgd = pgd_offset_k(addr);
+ if (pgd_none(*pgd)) {
+ p4d = vmem_crst_alloc(_REGION2_ENTRY_EMPTY);
+ if (!p4d)
+ goto out;
+ pgd_populate(&init_mm, pgd, p4d);
+ }
+ p4d = p4d_offset(pgd, addr);
+ if (p4d_none(*p4d)) {
+ pud = vmem_crst_alloc(_REGION3_ENTRY_EMPTY);
+ if (!pud)
+ goto out;
+ p4d_populate(&init_mm, p4d, pud);
+ }
+ pud = pud_offset(p4d, addr);
+ if (pud_none(*pud)) {
+ pmd = vmem_crst_alloc(_SEGMENT_ENTRY_EMPTY);
+ if (!pmd)
+ goto out;
+ pud_populate(&init_mm, pud, pmd);
+ } else if (WARN_ON_ONCE(pud_large(*pud))) {
+ goto out;
+ }
+ pmd = pmd_offset(pud, addr);
+ if (pmd_none(*pmd)) {
+ pte = vmem_pte_alloc();
+ if (!pte)
+ goto out;
+ pmd_populate(&init_mm, pmd, pte);
+ } else if (WARN_ON_ONCE(pmd_large(*pmd))) {
+ goto out;
+ }
+ ptep = pte_offset_kernel(pmd, addr);
+out:
+ return ptep;
+}
+
+int vmem_map_4k_page(unsigned long addr, unsigned long phys, pgprot_t prot)
+{
+ pte_t *ptep, pte;
+ int rc = 0;
+
+ if (!IS_ALIGNED(addr, PAGE_SIZE))
+ return -EINVAL;
+ mutex_lock(&vmem_mutex);
+ ptep = vmem_get_alloc_pte(addr);
+ if (!ptep) {
+ rc = -ENOMEM;
+ goto out;
+ }
+ __ptep_ipte(addr, ptep, 0, 0, IPTE_GLOBAL);
+ pte = mk_pte_phys(phys, prot);
+ set_pte(ptep, pte);
+out:
+ mutex_unlock(&vmem_mutex);
+ return rc;
+}
+
+void vmem_unmap_4k_page(unsigned long addr)
+{
+ pte_t *ptep;
+
+ mutex_lock(&vmem_mutex);
+ ptep = virt_to_kpte(addr);
+ __ptep_ipte(addr, ptep, 0, 0, IPTE_GLOBAL);
+ pte_clear(&init_mm, addr, ptep);
+ mutex_unlock(&vmem_mutex);
+}
+
/*
* map whole physical memory to virtual memory (identity mapping)
* we reserve enough space in the vmalloc area for vmemmap to hotplug
projects / kernel.git / commitdiff