Revert "s390/smp: rework absolute lowcore access"
This reverts commit 7d06fed77b7d8fc9f6cc41b4e3f2823d32532ad8.
This introduced vmem_mutex locking from vmem_map_4k_page()
function called from smp_reinit_ipl_cpu() with interrupts
disabled. While it is a pre-SMP early initcall no other CPUs
running in parallel nor other code taking vmem_mutex on this
boot stage - it still needs to be fixed.
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
diff --git a/arch/s390/boot/startup.c b/arch/s390/boot/startup.c
index 41b7af7..bc48fe8 100644
--- a/arch/s390/boot/startup.c
+++ b/arch/s390/boot/startup.c
@@ -10,13 +10,11 @@
#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);
@@ -182,8 +180,7 @@
/* force vmalloc and modules below kasan shadow */
vmax = min(vmax, KASAN_SHADOW_START);
#endif
- __abs_lowcore = round_down(vmax - ABS_LOWCORE_MAP_SIZE, sizeof(struct lowcore));
- MODULES_END = round_down(__abs_lowcore, _SEGMENT_SIZE);
+ MODULES_END = vmax;
MODULES_VADDR = MODULES_END - MODULES_LEN;
VMALLOC_END = MODULES_VADDR;
diff --git a/arch/s390/include/asm/abs_lowcore.h b/arch/s390/include/asm/abs_lowcore.h
deleted file mode 100644
index bdef8d2..0000000
--- a/arch/s390/include/asm/abs_lowcore.h
+++ /dev/null
@@ -1,17 +0,0 @@
-/* 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 */
diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h
index 82506eb..a397b07 100644
--- a/arch/s390/include/asm/pgtable.h
+++ b/arch/s390/include/asm/pgtable.h
@@ -1781,8 +1781,6 @@
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);
diff --git a/arch/s390/include/asm/processor.h b/arch/s390/include/asm/processor.h
index 93677ae..bd66f8e 100644
--- a/arch/s390/include/asm/processor.h
+++ b/arch/s390/include/asm/processor.h
@@ -307,6 +307,21 @@
#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);
diff --git a/arch/s390/kernel/Makefile b/arch/s390/kernel/Makefile
index 45e4b2f..3cbfa9f 100644
--- a/arch/s390/kernel/Makefile
+++ b/arch/s390/kernel/Makefile
@@ -40,7 +40,7 @@
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 abs_lowcore.o
+obj-y += smp.o text_amode31.o stacktrace.o
extra-y += head64.o vmlinux.lds
diff --git a/arch/s390/kernel/abs_lowcore.c b/arch/s390/kernel/abs_lowcore.c
deleted file mode 100644
index dc9f0ec..0000000
--- a/arch/s390/kernel/abs_lowcore.c
+++ /dev/null
@@ -1,88 +0,0 @@
-// 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();
-}
diff --git a/arch/s390/kernel/ipl.c b/arch/s390/kernel/ipl.c
index 325cbf6..1cc85b8 100644
--- a/arch/s390/kernel/ipl.c
+++ b/arch/s390/kernel/ipl.c
@@ -29,7 +29,6 @@
#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>
@@ -1643,16 +1642,12 @@
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);
- abs_lc = get_abs_lowcore(&flags);
- abs_lc->ipib = ipib;
- abs_lc->ipib_checksum = csum;
- put_abs_lowcore(abs_lc, flags);
+ put_abs_lowcore(ipib, ipib);
+ put_abs_lowcore(ipib_checksum, csum);
dump_run(trigger);
}
diff --git a/arch/s390/kernel/machine_kexec.c b/arch/s390/kernel/machine_kexec.c
index 4579b42..ab761c0 100644
--- a/arch/s390/kernel/machine_kexec.c
+++ b/arch/s390/kernel/machine_kexec.c
@@ -21,7 +21,6 @@
#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>
@@ -223,18 +222,13 @@
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());
- abs_lc = get_abs_lowcore(&flags);
- abs_lc->vmcore_info = paddr_vmcoreinfo_note();
- put_abs_lowcore(abs_lc, flags);
+ put_abs_lowcore(vmcore_info, paddr_vmcoreinfo_note());
}
void machine_shutdown(void)
diff --git a/arch/s390/kernel/os_info.c b/arch/s390/kernel/os_info.c
index 506ccb7..1acc2e0 100644
--- a/arch/s390/kernel/os_info.c
+++ b/arch/s390/kernel/os_info.c
@@ -13,7 +13,7 @@
#include <linux/kernel.h>
#include <linux/slab.h>
#include <asm/checksum.h>
-#include <asm/abs_lowcore.h>
+#include <asm/lowcore.h>
#include <asm/os_info.h>
#include <asm/asm-offsets.h>
@@ -57,16 +57,13 @@
*/
void __init os_info_init(void)
{
- struct lowcore *abs_lc;
- unsigned long flags;
+ void *ptr = &os_info;
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);
- abs_lc = get_abs_lowcore(&flags);
- abs_lc->os_info = __pa(&os_info);
- put_abs_lowcore(abs_lc, flags);
+ put_abs_lowcore(os_info, __pa(ptr));
}
#ifdef CONFIG_CRASH_DUMP
diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c
index 91139a1..8f48313 100644
--- a/arch/s390/kernel/setup.c
+++ b/arch/s390/kernel/setup.c
@@ -58,7 +58,7 @@
#include <asm/smp.h>
#include <asm/mmu_context.h>
#include <asm/cpcmd.h>
-#include <asm/abs_lowcore.h>
+#include <asm/lowcore.h>
#include <asm/nmi.h>
#include <asm/irq.h>
#include <asm/page.h>
@@ -411,9 +411,8 @@
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;
- unsigned long flags;
+ struct lowcore *lc;
if (IS_ENABLED(CONFIG_KASAN))
int_psw_mask |= PSW_MASK_DAT;
@@ -475,13 +474,11 @@
lc->restart_data = 0;
lc->restart_source = -1U;
- 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);
+ 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);
mcck_stack = (unsigned long)memblock_alloc(THREAD_SIZE, THREAD_SIZE);
if (!mcck_stack)
@@ -502,8 +499,8 @@
static void __init setup_lowcore_dat_on(void)
{
- struct lowcore *abs_lc;
- unsigned long flags;
+ struct lowcore *lc = lowcore_ptr[0];
+ int cr;
__ctl_clear_bit(0, 28);
S390_lowcore.external_new_psw.mask |= PSW_MASK_DAT;
@@ -512,15 +509,10 @@
S390_lowcore.io_new_psw.mask |= PSW_MASK_DAT;
__ctl_set_bit(0, 28);
__ctl_store(S390_lowcore.cregs_save_area, 0, 15);
- 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;
+ 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]);
}
static struct resource code_resource = {
diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
index 40876d8..30c91d56 100644
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -45,7 +45,7 @@
#include <asm/irq.h>
#include <asm/tlbflush.h>
#include <asm/vtimer.h>
-#include <asm/abs_lowcore.h>
+#include <asm/lowcore.h>
#include <asm/sclp.h>
#include <asm/debug.h>
#include <asm/os_info.h>
@@ -212,14 +212,10 @@
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);
@@ -241,7 +237,6 @@
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);
@@ -320,12 +315,9 @@
pcpu_delegate_fn *func,
void *data, unsigned long stack)
{
- struct lowcore *lc, *abs_lc;
- unsigned int source_cpu;
- unsigned long flags;
+ struct lowcore *lc = lowcore_ptr[pcpu - pcpu_devices];
+ unsigned int source_cpu = stap();
- 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,
@@ -340,12 +332,10 @@
lc->restart_data = (unsigned long)data;
lc->restart_source = source_cpu;
} else {
- 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);
+ 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);
}
__bpon();
asm volatile(
@@ -591,8 +581,6 @@
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) {
@@ -603,11 +591,9 @@
parms.andval = ~(1UL << bit);
}
spin_lock(&ctl_lock);
- abs_lc = get_abs_lowcore(&flags);
- ctlreg = abs_lc->cregs_save_area[cr];
+ get_abs_lowcore(ctlreg, cregs_save_area[cr]);
ctlreg = (ctlreg & parms.andval) | parms.orval;
- abs_lc->cregs_save_area[cr] = ctlreg;
- put_abs_lowcore(abs_lc, flags);
+ put_abs_lowcore(cregs_save_area[cr], ctlreg);
spin_unlock(&ctl_lock);
on_each_cpu(smp_ctl_bit_callback, &parms, 1);
}
@@ -1295,8 +1281,6 @@
__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);
diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c
index 7b6873ac..6a0ac00 100644
--- a/arch/s390/mm/init.c
+++ b/arch/s390/mm/init.c
@@ -38,7 +38,7 @@
#include <asm/kfence.h>
#include <asm/ptdump.h>
#include <asm/dma.h>
-#include <asm/abs_lowcore.h>
+#include <asm/lowcore.h>
#include <asm/tlb.h>
#include <asm/tlbflush.h>
#include <asm/sections.h>
diff --git a/arch/s390/mm/maccess.c b/arch/s390/mm/maccess.c
index b8451dd..d6d84e0 100644
--- a/arch/s390/mm/maccess.c
+++ b/arch/s390/mm/maccess.c
@@ -15,7 +15,6 @@
#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)
@@ -149,20 +148,46 @@
}
/*
- * Find CPU that owns swapped prefix page
+ * Copy memory in absolute mode (kernel to kernel)
*/
-static int get_swapped_owner(phys_addr_t addr)
+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)
{
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 cpu;
+ return 1;
}
- return -1;
+ return 0;
}
/*
@@ -175,35 +200,17 @@
{
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();
- this_cpu = get_cpu();
- if (addr >= sizeof(struct lowcore)) {
- cpu = get_swapped_owner(addr);
- if (cpu < 0)
- goto out;
+ 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);
}
- 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);
- }
-out:
- put_cpu();
+ preempt_enable();
cpus_read_unlock();
return bounce;
}
diff --git a/arch/s390/mm/vmem.c b/arch/s390/mm/vmem.c
index 203ba2b..c2583f9 100644
--- a/arch/s390/mm/vmem.c
+++ b/arch/s390/mm/vmem.c
@@ -561,91 +561,6 @@
}
/*
- * 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
* additional memory segments.
