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|
/*
* Page table handling routines for radix page table.
*
* Copyright 2015-2016, Aneesh Kumar K.V, IBM Corporation.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#define pr_fmt(fmt) "radix-mmu: " fmt
#include <linux/kernel.h>
#include <linux/sched/mm.h>
#include <linux/memblock.h>
#include <linux/of_fdt.h>
#include <linux/mm.h>
#include <linux/string_helpers.h>
#include <linux/stop_machine.h>
#include <asm/pgtable.h>
#include <asm/pgalloc.h>
#include <asm/mmu_context.h>
#include <asm/dma.h>
#include <asm/machdep.h>
#include <asm/mmu.h>
#include <asm/firmware.h>
#include <asm/powernv.h>
#include <asm/sections.h>
#include <asm/trace.h>
#include <trace/events/thp.h>
unsigned int mmu_pid_bits;
unsigned int mmu_base_pid;
static int native_register_process_table(unsigned long base, unsigned long pg_sz,
unsigned long table_size)
{
unsigned long patb0, patb1;
patb0 = be64_to_cpu(partition_tb[0].patb0);
patb1 = base | table_size | PATB_GR;
mmu_partition_table_set_entry(0, patb0, patb1);
return 0;
}
static __ref void *early_alloc_pgtable(unsigned long size, int nid,
unsigned long region_start, unsigned long region_end)
{
phys_addr_t min_addr = MEMBLOCK_LOW_LIMIT;
phys_addr_t max_addr = MEMBLOCK_ALLOC_ANYWHERE;
void *ptr;
if (region_start)
min_addr = region_start;
if (region_end)
max_addr = region_end;
ptr = memblock_alloc_try_nid(size, size, min_addr, max_addr, nid);
if (!ptr)
panic("%s: Failed to allocate %lu bytes align=0x%lx nid=%d from=%pa max_addr=%pa\n",
__func__, size, size, nid, &min_addr, &max_addr);
return ptr;
}
static int early_map_kernel_page(unsigned long ea, unsigned long pa,
pgprot_t flags,
unsigned int map_page_size,
int nid,
unsigned long region_start, unsigned long region_end)
{
unsigned long pfn = pa >> PAGE_SHIFT;
pgd_t *pgdp;
pud_t *pudp;
pmd_t *pmdp;
pte_t *ptep;
pgdp = pgd_offset_k(ea);
if (pgd_none(*pgdp)) {
pudp = early_alloc_pgtable(PUD_TABLE_SIZE, nid,
region_start, region_end);
pgd_populate(&init_mm, pgdp, pudp);
}
pudp = pud_offset(pgdp, ea);
if (map_page_size == PUD_SIZE) {
ptep = (pte_t *)pudp;
goto set_the_pte;
}
if (pud_none(*pudp)) {
pmdp = early_alloc_pgtable(PMD_TABLE_SIZE, nid,
region_start, region_end);
pud_populate(&init_mm, pudp, pmdp);
}
pmdp = pmd_offset(pudp, ea);
if (map_page_size == PMD_SIZE) {
ptep = pmdp_ptep(pmdp);
goto set_the_pte;
}
if (!pmd_present(*pmdp)) {
ptep = early_alloc_pgtable(PAGE_SIZE, nid,
region_start, region_end);
pmd_populate_kernel(&init_mm, pmdp, ptep);
}
ptep = pte_offset_kernel(pmdp, ea);
set_the_pte:
set_pte_at(&init_mm, ea, ptep, pfn_pte(pfn, flags));
smp_wmb();
return 0;
}
/*
* nid, region_start, and region_end are hints to try to place the page
* table memory in the same node or region.
*/
static int __map_kernel_page(unsigned long ea, unsigned long pa,
pgprot_t flags,
unsigned int map_page_size,
int nid,
unsigned long region_start, unsigned long region_end)
{
unsigned long pfn = pa >> PAGE_SHIFT;
pgd_t *pgdp;
pud_t *pudp;
pmd_t *pmdp;
pte_t *ptep;
/*
* Make sure task size is correct as per the max adddr
*/
BUILD_BUG_ON(TASK_SIZE_USER64 > RADIX_PGTABLE_RANGE);
if (unlikely(!slab_is_available()))
return early_map_kernel_page(ea, pa, flags, map_page_size,
nid, region_start, region_end);
/*
* Should make page table allocation functions be able to take a
* node, so we can place kernel page tables on the right nodes after
* boot.
*/
pgdp = pgd_offset_k(ea);
pudp = pud_alloc(&init_mm, pgdp, ea);
if (!pudp)
return -ENOMEM;
if (map_page_size == PUD_SIZE) {
ptep = (pte_t *)pudp;
goto set_the_pte;
}
pmdp = pmd_alloc(&init_mm, pudp, ea);
if (!pmdp)
return -ENOMEM;
if (map_page_size == PMD_SIZE) {
ptep = pmdp_ptep(pmdp);
goto set_the_pte;
}
ptep = pte_alloc_kernel(pmdp, ea);
if (!ptep)
return -ENOMEM;
set_the_pte:
set_pte_at(&init_mm, ea, ptep, pfn_pte(pfn, flags));
smp_wmb();
return 0;
}
int radix__map_kernel_page(unsigned long ea, unsigned long pa,
pgprot_t flags,
unsigned int map_page_size)
{
return __map_kernel_page(ea, pa, flags, map_page_size, -1, 0, 0);
}
#ifdef CONFIG_STRICT_KERNEL_RWX
void radix__change_memory_range(unsigned long start, unsigned long end,
unsigned long clear)
{
unsigned long idx;
pgd_t *pgdp;
pud_t *pudp;
pmd_t *pmdp;
pte_t *ptep;
start = ALIGN_DOWN(start, PAGE_SIZE);
end = PAGE_ALIGN(end); // aligns up
pr_debug("Changing flags on range %lx-%lx removing 0x%lx\n",
start, end, clear);
for (idx = start; idx < end; idx += PAGE_SIZE) {
pgdp = pgd_offset_k(idx);
pudp = pud_alloc(&init_mm, pgdp, idx);
if (!pudp)
continue;
if (pud_huge(*pudp)) {
ptep = (pte_t *)pudp;
goto update_the_pte;
}
pmdp = pmd_alloc(&init_mm, pudp, idx);
if (!pmdp)
continue;
if (pmd_huge(*pmdp)) {
ptep = pmdp_ptep(pmdp);
goto update_the_pte;
}
ptep = pte_alloc_kernel(pmdp, idx);
if (!ptep)
continue;
update_the_pte:
radix__pte_update(&init_mm, idx, ptep, clear, 0, 0);
}
radix__flush_tlb_kernel_range(start, end);
}
void radix__mark_rodata_ro(void)
{
unsigned long start, end;
start = (unsigned long)_stext;
end = (unsigned long)__init_begin;
radix__change_memory_range(start, end, _PAGE_WRITE);
}
void radix__mark_initmem_nx(void)
{
unsigned long start = (unsigned long)__init_begin;
unsigned long end = (unsigned long)__init_end;
radix__change_memory_range(start, end, _PAGE_EXEC);
}
#endif /* CONFIG_STRICT_KERNEL_RWX */
static inline void __meminit
print_mapping(unsigned long start, unsigned long end, unsigned long size, bool exec)
{
char buf[10];
if (end <= start)
return;
string_get_size(size, 1, STRING_UNITS_2, buf, sizeof(buf));
pr_info("Mapped 0x%016lx-0x%016lx with %s pages%s\n", start, end, buf,
exec ? " (exec)" : "");
}
static unsigned long next_boundary(unsigned long addr, unsigned long end)
{
#ifdef CONFIG_STRICT_KERNEL_RWX
if (addr < __pa_symbol(__init_begin))
return __pa_symbol(__init_begin);
#endif
return end;
}
static int __meminit create_physical_mapping(unsigned long start,
unsigned long end,
int nid)
{
unsigned long vaddr, addr, mapping_size = 0;
bool prev_exec, exec = false;
pgprot_t prot;
int psize;
start = _ALIGN_UP(start, PAGE_SIZE);
for (addr = start; addr < end; addr += mapping_size) {
unsigned long gap, previous_size;
int rc;
gap = next_boundary(addr, end) - addr;
previous_size = mapping_size;
prev_exec = exec;
if (IS_ALIGNED(addr, PUD_SIZE) && gap >= PUD_SIZE &&
mmu_psize_defs[MMU_PAGE_1G].shift) {
mapping_size = PUD_SIZE;
psize = MMU_PAGE_1G;
} else if (IS_ALIGNED(addr, PMD_SIZE) && gap >= PMD_SIZE &&
mmu_psize_defs[MMU_PAGE_2M].shift) {
mapping_size = PMD_SIZE;
psize = MMU_PAGE_2M;
} else {
mapping_size = PAGE_SIZE;
psize = mmu_virtual_psize;
}
vaddr = (unsigned long)__va(addr);
if (overlaps_kernel_text(vaddr, vaddr + mapping_size) ||
overlaps_interrupt_vector_text(vaddr, vaddr + mapping_size)) {
prot = PAGE_KERNEL_X;
exec = true;
} else {
prot = PAGE_KERNEL;
exec = false;
}
if (mapping_size != previous_size || exec != prev_exec) {
print_mapping(start, addr, previous_size, prev_exec);
start = addr;
}
rc = __map_kernel_page(vaddr, addr, prot, mapping_size, nid, start, end);
if (rc)
return rc;
update_page_count(psize, 1);
}
print_mapping(start, addr, mapping_size, exec);
return 0;
}
void __init radix_init_pgtable(void)
{
unsigned long rts_field;
struct memblock_region *reg;
/* We don't support slb for radix */
mmu_slb_size = 0;
/*
* Create the linear mapping, using standard page size for now
*/
for_each_memblock(memory, reg) {
/*
* The memblock allocator is up at this point, so the
* page tables will be allocated within the range. No
* need or a node (which we don't have yet).
*/
WARN_ON(create_physical_mapping(reg->base,
reg->base + reg->size,
-1));
}
/* Find out how many PID bits are supported */
if (cpu_has_feature(CPU_FTR_HVMODE)) {
if (!mmu_pid_bits)
mmu_pid_bits = 20;
#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
/*
* When KVM is possible, we only use the top half of the
* PID space to avoid collisions between host and guest PIDs
* which can cause problems due to prefetch when exiting the
* guest with AIL=3
*/
mmu_base_pid = 1 << (mmu_pid_bits - 1);
#else
mmu_base_pid = 1;
#endif
} else {
/* The guest uses the bottom half of the PID space */
if (!mmu_pid_bits)
mmu_pid_bits = 19;
mmu_base_pid = 1;
}
/*
* Allocate Partition table and process table for the
* host.
*/
BUG_ON(PRTB_SIZE_SHIFT > 36);
process_tb = early_alloc_pgtable(1UL << PRTB_SIZE_SHIFT, -1, 0, 0);
/*
* Fill in the process table.
*/
rts_field = radix__get_tree_size();
process_tb->prtb0 = cpu_to_be64(rts_field | __pa(init_mm.pgd) | RADIX_PGD_INDEX_SIZE);
/*
* Fill in the partition table. We are suppose to use effective address
* of process table here. But our linear mapping also enable us to use
* physical address here.
*/
register_process_table(__pa(process_tb), 0, PRTB_SIZE_SHIFT - 12);
pr_info("Process table %p and radix root for kernel: %p\n", process_tb, init_mm.pgd);
asm volatile("ptesync" : : : "memory");
asm volatile(PPC_TLBIE_5(%0,%1,2,1,1) : :
"r" (TLBIEL_INVAL_SET_LPID), "r" (0));
asm volatile("eieio; tlbsync; ptesync" : : : "memory");
trace_tlbie(0, 0, TLBIEL_INVAL_SET_LPID, 0, 2, 1, 1);
/*
* The init_mm context is given the first available (non-zero) PID,
* which is the "guard PID" and contains no page table. PIDR should
* never be set to zero because that duplicates the kernel address
* space at the 0x0... offset (quadrant 0)!
*
* An arbitrary PID that may later be allocated by the PID allocator
* for userspace processes must not be used either, because that
* would cause stale user mappings for that PID on CPUs outside of
* the TLB invalidation scheme (because it won't be in mm_cpumask).
*
* So permanently carve out one PID for the purpose of a guard PID.
*/
init_mm.context.id = mmu_base_pid;
mmu_base_pid++;
}
static void __init radix_init_partition_table(void)
{
unsigned long rts_field, dw0;
mmu_partition_table_init();
rts_field = radix__get_tree_size();
dw0 = rts_field | __pa(init_mm.pgd) | RADIX_PGD_INDEX_SIZE | PATB_HR;
mmu_partition_table_set_entry(0, dw0, 0);
pr_info("Initializing Radix MMU\n");
pr_info("Partition table %p\n", partition_tb);
}
void __init radix_init_native(void)
{
register_process_table = native_register_process_table;
}
static int __init get_idx_from_shift(unsigned int shift)
{
int idx = -1;
switch (shift) {
case 0xc:
idx = MMU_PAGE_4K;
break;
case 0x10:
idx = MMU_PAGE_64K;
break;
case 0x15:
idx = MMU_PAGE_2M;
break;
case 0x1e:
idx = MMU_PAGE_1G;
break;
}
return idx;
}
static int __init radix_dt_scan_page_sizes(unsigned long node,
const char *uname, int depth,
void *data)
{
int size = 0;
int shift, idx;
unsigned int ap;
const __be32 *prop;
const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
/* We are scanning "cpu" nodes only */
if (type == NULL || strcmp(type, "cpu") != 0)
return 0;
/* Find MMU PID size */
prop = of_get_flat_dt_prop(node, "ibm,mmu-pid-bits", &size);
if (prop && size == 4)
mmu_pid_bits = be32_to_cpup(prop);
/* Grab page size encodings */
prop = of_get_flat_dt_prop(node, "ibm,processor-radix-AP-encodings", &size);
if (!prop)
return 0;
pr_info("Page sizes from device-tree:\n");
for (; size >= 4; size -= 4, ++prop) {
struct mmu_psize_def *def;
/* top 3 bit is AP encoding */
shift = be32_to_cpu(prop[0]) & ~(0xe << 28);
ap = be32_to_cpu(prop[0]) >> 29;
pr_info("Page size shift = %d AP=0x%x\n", shift, ap);
idx = get_idx_from_shift(shift);
if (idx < 0)
continue;
def = &mmu_psize_defs[idx];
def->shift = shift;
def->ap = ap;
}
/* needed ? */
cur_cpu_spec->mmu_features &= ~MMU_FTR_NO_SLBIE_B;
return 1;
}
void __init radix__early_init_devtree(void)
{
int rc;
/*
* Try to find the available page sizes in the device-tree
*/
rc = of_scan_flat_dt(radix_dt_scan_page_sizes, NULL);
if (rc != 0) /* Found */
goto found;
/*
* let's assume we have page 4k and 64k support
*/
mmu_psize_defs[MMU_PAGE_4K].shift = 12;
mmu_psize_defs[MMU_PAGE_4K].ap = 0x0;
mmu_psize_defs[MMU_PAGE_64K].shift = 16;
mmu_psize_defs[MMU_PAGE_64K].ap = 0x5;
found:
#ifdef CONFIG_SPARSEMEM_VMEMMAP
if (mmu_psize_defs[MMU_PAGE_2M].shift) {
/*
* map vmemmap using 2M if available
*/
mmu_vmemmap_psize = MMU_PAGE_2M;
}
#endif /* CONFIG_SPARSEMEM_VMEMMAP */
return;
}
static void radix_init_amor(void)
{
/*
* In HV mode, we init AMOR (Authority Mask Override Register) so that
* the hypervisor and guest can setup IAMR (Instruction Authority Mask
* Register), enable key 0 and set it to 1.
*
* AMOR = 0b1100 .... 0000 (Mask for key 0 is 11)
*/
mtspr(SPRN_AMOR, (3ul << 62));
}
static void radix_init_iamr(void)
{
/*
* Radix always uses key0 of the IAMR to determine if an access is
* allowed. We set bit 0 (IBM bit 1) of key0, to prevent instruction
* fetch.
*/
mtspr(SPRN_IAMR, (1ul << 62));
}
void __init radix__early_init_mmu(void)
{
unsigned long lpcr;
#ifdef CONFIG_PPC_64K_PAGES
/* PAGE_SIZE mappings */
mmu_virtual_psize = MMU_PAGE_64K;
#else
mmu_virtual_psize = MMU_PAGE_4K;
#endif
#ifdef CONFIG_SPARSEMEM_VMEMMAP
/* vmemmap mapping */
mmu_vmemmap_psize = mmu_virtual_psize;
#endif
/*
* initialize page table size
*/
__pte_index_size = RADIX_PTE_INDEX_SIZE;
__pmd_index_size = RADIX_PMD_INDEX_SIZE;
__pud_index_size = RADIX_PUD_INDEX_SIZE;
__pgd_index_size = RADIX_PGD_INDEX_SIZE;
__pud_cache_index = RADIX_PUD_INDEX_SIZE;
__pte_table_size = RADIX_PTE_TABLE_SIZE;
__pmd_table_size = RADIX_PMD_TABLE_SIZE;
__pud_table_size = RADIX_PUD_TABLE_SIZE;
__pgd_table_size = RADIX_PGD_TABLE_SIZE;
__pmd_val_bits = RADIX_PMD_VAL_BITS;
__pud_val_bits = RADIX_PUD_VAL_BITS;
__pgd_val_bits = RADIX_PGD_VAL_BITS;
__kernel_virt_start = RADIX_KERN_VIRT_START;
__kernel_virt_size = RADIX_KERN_VIRT_SIZE;
__vmalloc_start = RADIX_VMALLOC_START;
__vmalloc_end = RADIX_VMALLOC_END;
__kernel_io_start = RADIX_KERN_IO_START;
vmemmap = (struct page *)RADIX_VMEMMAP_BASE;
ioremap_bot = IOREMAP_BASE;
#ifdef CONFIG_PCI
pci_io_base = ISA_IO_BASE;
#endif
__pte_frag_nr = RADIX_PTE_FRAG_NR;
__pte_frag_size_shift = RADIX_PTE_FRAG_SIZE_SHIFT;
__pmd_frag_nr = RADIX_PMD_FRAG_NR;
__pmd_frag_size_shift = RADIX_PMD_FRAG_SIZE_SHIFT;
if (!firmware_has_feature(FW_FEATURE_LPAR)) {
radix_init_native();
lpcr = mfspr(SPRN_LPCR);
mtspr(SPRN_LPCR, lpcr | LPCR_UPRT | LPCR_HR);
radix_init_partition_table();
radix_init_amor();
} else {
radix_init_pseries();
}
memblock_set_current_limit(MEMBLOCK_ALLOC_ANYWHERE);
radix_init_iamr();
radix_init_pgtable();
/* Switch to the guard PID before turning on MMU */
radix__switch_mmu_context(NULL, &init_mm);
if (cpu_has_feature(CPU_FTR_HVMODE))
tlbiel_all();
}
void radix__early_init_mmu_secondary(void)
{
unsigned long lpcr;
/*
* update partition table control register and UPRT
*/
if (!firmware_has_feature(FW_FEATURE_LPAR)) {
lpcr = mfspr(SPRN_LPCR);
mtspr(SPRN_LPCR, lpcr | LPCR_UPRT | LPCR_HR);
mtspr(SPRN_PTCR,
__pa(partition_tb) | (PATB_SIZE_SHIFT - 12));
radix_init_amor();
}
radix_init_iamr();
radix__switch_mmu_context(NULL, &init_mm);
if (cpu_has_feature(CPU_FTR_HVMODE))
tlbiel_all();
}
void radix__mmu_cleanup_all(void)
{
unsigned long lpcr;
if (!firmware_has_feature(FW_FEATURE_LPAR)) {
lpcr = mfspr(SPRN_LPCR);
mtspr(SPRN_LPCR, lpcr & ~LPCR_UPRT);
mtspr(SPRN_PTCR, 0);
powernv_set_nmmu_ptcr(0);
radix__flush_tlb_all();
}
}
void radix__setup_initial_memory_limit(phys_addr_t first_memblock_base,
phys_addr_t first_memblock_size)
{
/* We don't currently support the first MEMBLOCK not mapping 0
* physical on those processors
*/
BUG_ON(first_memblock_base != 0);
/*
* Radix mode is not limited by RMA / VRMA addressing.
*/
ppc64_rma_size = ULONG_MAX;
}
#ifdef CONFIG_MEMORY_HOTPLUG
static void free_pte_table(pte_t *pte_start, pmd_t *pmd)
{
pte_t *pte;
int i;
for (i = 0; i < PTRS_PER_PTE; i++) {
pte = pte_start + i;
if (!pte_none(*pte))
return;
}
pte_free_kernel(&init_mm, pte_start);
pmd_clear(pmd);
}
static void free_pmd_table(pmd_t *pmd_start, pud_t *pud)
{
pmd_t *pmd;
int i;
for (i = 0; i < PTRS_PER_PMD; i++) {
pmd = pmd_start + i;
if (!pmd_none(*pmd))
return;
}
pmd_free(&init_mm, pmd_start);
pud_clear(pud);
}
struct change_mapping_params {
pte_t *pte;
unsigned long start;
unsigned long end;
unsigned long aligned_start;
unsigned long aligned_end;
};
static int __meminit stop_machine_change_mapping(void *data)
{
struct change_mapping_params *params =
(struct change_mapping_params *)data;
if (!data)
return -1;
spin_unlock(&init_mm.page_table_lock);
pte_clear(&init_mm, params->aligned_start, params->pte);
create_physical_mapping(params->aligned_start, params->start, -1);
create_physical_mapping(params->end, params->aligned_end, -1);
spin_lock(&init_mm.page_table_lock);
return 0;
}
static void remove_pte_table(pte_t *pte_start, unsigned long addr,
unsigned long end)
{
unsigned long next;
pte_t *pte;
pte = pte_start + pte_index(addr);
for (; addr < end; addr = next, pte++) {
next = (addr + PAGE_SIZE) & PAGE_MASK;
if (next > end)
next = end;
if (!pte_present(*pte))
continue;
if (!PAGE_ALIGNED(addr) || !PAGE_ALIGNED(next)) {
/*
* The vmemmap_free() and remove_section_mapping()
* codepaths call us with aligned addresses.
*/
WARN_ONCE(1, "%s: unaligned range\n", __func__);
continue;
}
pte_clear(&init_mm, addr, pte);
}
}
/*
* clear the pte and potentially split the mapping helper
*/
static void __meminit split_kernel_mapping(unsigned long addr, unsigned long end,
unsigned long size, pte_t *pte)
{
unsigned long mask = ~(size - 1);
unsigned long aligned_start = addr & mask;
unsigned long aligned_end = addr + size;
struct change_mapping_params params;
bool split_region = false;
if ((end - addr) < size) {
/*
* We're going to clear the PTE, but not flushed
* the mapping, time to remap and flush. The
* effects if visible outside the processor or
* if we are running in code close to the
* mapping we cleared, we are in trouble.
*/
if (overlaps_kernel_text(aligned_start, addr) ||
overlaps_kernel_text(end, aligned_end)) {
/*
* Hack, just return, don't pte_clear
*/
WARN_ONCE(1, "Linear mapping %lx->%lx overlaps kernel "
"text, not splitting\n", addr, end);
return;
}
split_region = true;
}
if (split_region) {
params.pte = pte;
params.start = addr;
params.end = end;
params.aligned_start = addr & ~(size - 1);
params.aligned_end = min_t(unsigned long, aligned_end,
(unsigned long)__va(memblock_end_of_DRAM()));
stop_machine(stop_machine_change_mapping, ¶ms, NULL);
return;
}
pte_clear(&init_mm, addr, pte);
}
static void remove_pmd_table(pmd_t *pmd_start, unsigned long addr,
unsigned long end)
{
unsigned long next;
pte_t *pte_base;
pmd_t *pmd;
pmd = pmd_start + pmd_index(addr);
for (; addr < end; addr = next, pmd++) {
next = pmd_addr_end(addr, end);
if (!pmd_present(*pmd))
continue;
if (pmd_huge(*pmd)) {
split_kernel_mapping(addr, end, PMD_SIZE, (pte_t *)pmd);
continue;
}
pte_base = (pte_t *)pmd_page_vaddr(*pmd);
remove_pte_table(pte_base, addr, next);
free_pte_table(pte_base, pmd);
}
}
static void remove_pud_table(pud_t *pud_start, unsigned long addr,
unsigned long end)
{
unsigned long next;
pmd_t *pmd_base;
pud_t *pud;
pud = pud_start + pud_index(addr);
for (; addr < end; addr = next, pud++) {
next = pud_addr_end(addr, end);
if (!pud_present(*pud))
continue;
if (pud_huge(*pud)) {
split_kernel_mapping(addr, end, PUD_SIZE, (pte_t *)pud);
continue;
}
pmd_base = (pmd_t *)pud_page_vaddr(*pud);
remove_pmd_table(pmd_base, addr, next);
free_pmd_table(pmd_base, pud);
}
}
static void __meminit remove_pagetable(unsigned long start, unsigned long end)
{
unsigned long addr, next;
pud_t *pud_base;
pgd_t *pgd;
spin_lock(&init_mm.page_table_lock);
for (addr = start; addr < end; addr = next) {
next = pgd_addr_end(addr, end);
pgd = pgd_offset_k(addr);
if (!pgd_present(*pgd))
continue;
if (pgd_huge(*pgd)) {
split_kernel_mapping(addr, end, PGDIR_SIZE, (pte_t *)pgd);
continue;
}
pud_base = (pud_t *)pgd_page_vaddr(*pgd);
remove_pud_table(pud_base, addr, next);
}
spin_unlock(&init_mm.page_table_lock);
radix__flush_tlb_kernel_range(start, end);
}
int __meminit radix__create_section_mapping(unsigned long start, unsigned long end, int nid)
{
return create_physical_mapping(start, end, nid);
}
int __meminit radix__remove_section_mapping(unsigned long start, unsigned long end)
{
remove_pagetable(start, end);
return 0;
}
#endif /* CONFIG_MEMORY_HOTPLUG */
#ifdef CONFIG_SPARSEMEM_VMEMMAP
static int __map_kernel_page_nid(unsigned long ea, unsigned long pa,
pgprot_t flags, unsigned int map_page_size,
int nid)
{
return __map_kernel_page(ea, pa, flags, map_page_size, nid, 0, 0);
}
int __meminit radix__vmemmap_create_mapping(unsigned long start,
unsigned long page_size,
unsigned long phys)
{
/* Create a PTE encoding */
unsigned long flags = _PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_KERNEL_RW;
int nid = early_pfn_to_nid(phys >> PAGE_SHIFT);
int ret;
ret = __map_kernel_page_nid(start, phys, __pgprot(flags), page_size, nid);
BUG_ON(ret);
return 0;
}
#ifdef CONFIG_MEMORY_HOTPLUG
void __meminit radix__vmemmap_remove_mapping(unsigned long start, unsigned long page_size)
{
remove_pagetable(start, start + page_size);
}
#endif
#endif
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
unsigned long radix__pmd_hugepage_update(struct mm_struct *mm, unsigned long addr,
pmd_t *pmdp, unsigned long clr,
unsigned long set)
{
unsigned long old;
#ifdef CONFIG_DEBUG_VM
WARN_ON(!radix__pmd_trans_huge(*pmdp) && !pmd_devmap(*pmdp));
assert_spin_locked(pmd_lockptr(mm, pmdp));
#endif
old = radix__pte_update(mm, addr, (pte_t *)pmdp, clr, set, 1);
trace_hugepage_update(addr, old, clr, set);
return old;
}
pmd_t radix__pmdp_collapse_flush(struct vm_area_struct *vma, unsigned long address,
pmd_t *pmdp)
{
pmd_t pmd;
VM_BUG_ON(address & ~HPAGE_PMD_MASK);
VM_BUG_ON(radix__pmd_trans_huge(*pmdp));
VM_BUG_ON(pmd_devmap(*pmdp));
/*
* khugepaged calls this for normal pmd
*/
pmd = *pmdp;
pmd_clear(pmdp);
/*FIXME!! Verify whether we need this kick below */
serialize_against_pte_lookup(vma->vm_mm);
radix__flush_tlb_collapsed_pmd(vma->vm_mm, address);
return pmd;
}
/*
* For us pgtable_t is pte_t *. Inorder to save the deposisted
* page table, we consider the allocated page table as a list
* head. On withdraw we need to make sure we zero out the used
* list_head memory area.
*/
void radix__pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp,
pgtable_t pgtable)
{
struct list_head *lh = (struct list_head *) pgtable;
assert_spin_locked(pmd_lockptr(mm, pmdp));
/* FIFO */
if (!pmd_huge_pte(mm, pmdp))
INIT_LIST_HEAD(lh);
else
list_add(lh, (struct list_head *) pmd_huge_pte(mm, pmdp));
pmd_huge_pte(mm, pmdp) = pgtable;
}
pgtable_t radix__pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp)
{
pte_t *ptep;
pgtable_t pgtable;
struct list_head *lh;
assert_spin_locked(pmd_lockptr(mm, pmdp));
/* FIFO */
pgtable = pmd_huge_pte(mm, pmdp);
lh = (struct list_head *) pgtable;
if (list_empty(lh))
pmd_huge_pte(mm, pmdp) = NULL;
else {
pmd_huge_pte(mm, pmdp) = (pgtable_t) lh->next;
list_del(lh);
}
ptep = (pte_t *) pgtable;
*ptep = __pte(0);
ptep++;
*ptep = __pte(0);
return pgtable;
}
pmd_t radix__pmdp_huge_get_and_clear(struct mm_struct *mm,
unsigned long addr, pmd_t *pmdp)
{
pmd_t old_pmd;
unsigned long old;
old = radix__pmd_hugepage_update(mm, addr, pmdp, ~0UL, 0);
old_pmd = __pmd(old);
/*
* Serialize against find_current_mm_pte which does lock-less
* lookup in page tables with local interrupts disabled. For huge pages
* it casts pmd_t to pte_t. Since format of pte_t is different from
* pmd_t we want to prevent transit from pmd pointing to page table
* to pmd pointing to huge page (and back) while interrupts are disabled.
* We clear pmd to possibly replace it with page table pointer in
* different code paths. So make sure we wait for the parallel
* find_current_mm_pte to finish.
*/
serialize_against_pte_lookup(mm);
return old_pmd;
}
int radix__has_transparent_hugepage(void)
{
/* For radix 2M at PMD level means thp */
if (mmu_psize_defs[MMU_PAGE_2M].shift == PMD_SHIFT)
return 1;
return 0;
}
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
void radix__ptep_set_access_flags(struct vm_area_struct *vma, pte_t *ptep,
pte_t entry, unsigned long address, int psize)
{
struct mm_struct *mm = vma->vm_mm;
unsigned long set = pte_val(entry) & (_PAGE_DIRTY | _PAGE_ACCESSED |
_PAGE_RW | _PAGE_EXEC);
unsigned long change = pte_val(entry) ^ pte_val(*ptep);
/*
* To avoid NMMU hang while relaxing access, we need mark
* the pte invalid in between.
*/
if ((change & _PAGE_RW) && atomic_read(&mm->context.copros) > 0) {
unsigned long old_pte, new_pte;
old_pte = __radix_pte_update(ptep, _PAGE_PRESENT, _PAGE_INVALID);
/*
* new value of pte
*/
new_pte = old_pte | set;
radix__flush_tlb_page_psize(mm, address, psize);
__radix_pte_update(ptep, _PAGE_INVALID, new_pte);
} else {
__radix_pte_update(ptep, 0, set);
/*
* Book3S does not require a TLB flush when relaxing access
* restrictions when the address space is not attached to a
* NMMU, because the core MMU will reload the pte after taking
* an access fault, which is defined by the architectue.
*/
}
/* See ptesync comment in radix__set_pte_at */
}
void radix__ptep_modify_prot_commit(struct vm_area_struct *vma,
unsigned long addr, pte_t *ptep,
pte_t old_pte, pte_t pte)
{
struct mm_struct *mm = vma->vm_mm;
/*
* To avoid NMMU hang while relaxing access we need to flush the tlb before
* we set the new value. We need to do this only for radix, because hash
* translation does flush when updating the linux pte.
*/
if (is_pte_rw_upgrade(pte_val(old_pte), pte_val(pte)) &&
(atomic_read(&mm->context.copros) > 0))
radix__flush_tlb_page(vma, addr);
set_pte_at(mm, addr, ptep, pte);
}
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