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kernel-fxtec-pro1x/arch/powerpc/mm/hash_utils_64.c
Aneesh Kumar K.V 0ac52dd766 powerpc: Make linux pagetable walk safe with THP enabled 
We need to have irqs disabled to handle all the possible parallel update for
linux page table without holding locks.

Events that we are intersted in while walking page tables are
1) Page fault
2) umap
3) THP split
4) THP collapse

A) local_irq_disabled:
------------------------
1) page fault:
A none to valid transition via page fault is not an issue because we
would either see a none or valid. If it is none, we would error out
the page table walk. We may need to use on stack values when checking for
type of page table elements, because if we do

if (!is_hugepd()) {
    if (!pmd_none() {
       if (pmd_bad() {

We could take that bad condition because the pmd got converted to a hugepd
after the !is_hugepd check via a hugetlb fault.

The right way would be to check for pmd_none higher up or use on stack value.

2) A valid to none conversion via unmap:
We can safely walk the upper level table, because we don't remove the the
page table entries until rcu grace period. So even if we followed a
wrong pointer we still have the pointer valid till the grace period.

A PTE pointer returned need to be atomically checked for _PAGE_PRESENT and
 _PAGE_BUSY. A valid pointer returned could becoming none later. To prevent
pte_clear we take _PAGE_BUSY.

3) THP split:
A valid transparent hugepage is converted to nomal page. Before we split we
do pmd_splitting_flush, which sets the hugepage PTE to _PAGE_SPLITTING
So when walking page table we need to check for pmd_trans_splitting and
handle that. The pte returned should also need to be checked for
_PAGE_SPLITTING before setting _PAGE_BUSY similar to _PAGE_PRESENT. We save
the value of PTE on stack and check for the flag in the local pte value.
If we don't have the value set we can safely operate on the local pte value
and we atomicaly set _PAGE_BUSY.

4) THP collapse:
A normal page gets converted to hugepage. In the collapse path, we
mark the pmd none early (pmdp_clear_flush). With irq disabled, if we
are aleady walking page table we would see the pmd_none and won't continue.
If we see a valid PMD, we should still check for _PAGE_PRESENT before
setting _PAGE_BUSY, to make sure we didn't collapse the PTE to a Huge PTE.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-06-21 16:01:56 +10:00

1436 lines
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/*
* PowerPC64 port by Mike Corrigan and Dave Engebretsen
* {mikejc|engebret}@us.ibm.com
*
* Copyright (c) 2000 Mike Corrigan <mikejc@us.ibm.com>
*
* SMP scalability work:
* Copyright (C) 2001 Anton Blanchard <anton@au.ibm.com>, IBM
*
* Module name: htab.c
*
* Description:
* PowerPC Hashed Page Table functions
*
* 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.
*/
#undef DEBUG
#undef DEBUG_LOW
#include <linux/spinlock.h>
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/proc_fs.h>
#include <linux/stat.h>
#include <linux/sysctl.h>
#include <linux/export.h>
#include <linux/ctype.h>
#include <linux/cache.h>
#include <linux/init.h>
#include <linux/signal.h>
#include <linux/memblock.h>
#include <linux/context_tracking.h>
#include <asm/processor.h>
#include <asm/pgtable.h>
#include <asm/mmu.h>
#include <asm/mmu_context.h>
#include <asm/page.h>
#include <asm/types.h>
#include <asm/uaccess.h>
#include <asm/machdep.h>
#include <asm/prom.h>
#include <asm/tlbflush.h>
#include <asm/io.h>
#include <asm/eeh.h>
#include <asm/tlb.h>
#include <asm/cacheflush.h>
#include <asm/cputable.h>
#include <asm/sections.h>
#include <asm/spu.h>
#include <asm/udbg.h>
#include <asm/code-patching.h>
#include <asm/fadump.h>
#include <asm/firmware.h>
#include <asm/tm.h>
#ifdef DEBUG
#define DBG(fmt...) udbg_printf(fmt)
#else
#define DBG(fmt...)
#endif
#ifdef DEBUG_LOW
#define DBG_LOW(fmt...) udbg_printf(fmt)
#else
#define DBG_LOW(fmt...)
#endif
#define KB (1024)
#define MB (1024*KB)
#define GB (1024L*MB)
/*
* Note: pte --> Linux PTE
* HPTE --> PowerPC Hashed Page Table Entry
*
* Execution context:
* htab_initialize is called with the MMU off (of course), but
* the kernel has been copied down to zero so it can directly
* reference global data. At this point it is very difficult
* to print debug info.
*
*/
#ifdef CONFIG_U3_DART
extern unsigned long dart_tablebase;
#endif /* CONFIG_U3_DART */
static unsigned long _SDR1;
struct mmu_psize_def mmu_psize_defs[MMU_PAGE_COUNT];
struct hash_pte *htab_address;
unsigned long htab_size_bytes;
unsigned long htab_hash_mask;
EXPORT_SYMBOL_GPL(htab_hash_mask);
int mmu_linear_psize = MMU_PAGE_4K;
int mmu_virtual_psize = MMU_PAGE_4K;
int mmu_vmalloc_psize = MMU_PAGE_4K;
#ifdef CONFIG_SPARSEMEM_VMEMMAP
int mmu_vmemmap_psize = MMU_PAGE_4K;
#endif
int mmu_io_psize = MMU_PAGE_4K;
int mmu_kernel_ssize = MMU_SEGSIZE_256M;
int mmu_highuser_ssize = MMU_SEGSIZE_256M;
u16 mmu_slb_size = 64;
EXPORT_SYMBOL_GPL(mmu_slb_size);
#ifdef CONFIG_PPC_64K_PAGES
int mmu_ci_restrictions;
#endif
#ifdef CONFIG_DEBUG_PAGEALLOC
static u8 *linear_map_hash_slots;
static unsigned long linear_map_hash_count;
static DEFINE_SPINLOCK(linear_map_hash_lock);
#endif /* CONFIG_DEBUG_PAGEALLOC */
/* There are definitions of page sizes arrays to be used when none
* is provided by the firmware.
*/
/* Pre-POWER4 CPUs (4k pages only)
*/
static struct mmu_psize_def mmu_psize_defaults_old[] = {
[MMU_PAGE_4K] = {
.shift = 12,
.sllp = 0,
.penc = {[MMU_PAGE_4K] = 0, [1 ... MMU_PAGE_COUNT - 1] = -1},
.avpnm = 0,
.tlbiel = 0,
},
};
/* POWER4, GPUL, POWER5
*
* Support for 16Mb large pages
*/
static struct mmu_psize_def mmu_psize_defaults_gp[] = {
[MMU_PAGE_4K] = {
.shift = 12,
.sllp = 0,
.penc = {[MMU_PAGE_4K] = 0, [1 ... MMU_PAGE_COUNT - 1] = -1},
.avpnm = 0,
.tlbiel = 1,
},
[MMU_PAGE_16M] = {
.shift = 24,
.sllp = SLB_VSID_L,
.penc = {[0 ... MMU_PAGE_16M - 1] = -1, [MMU_PAGE_16M] = 0,
[MMU_PAGE_16M + 1 ... MMU_PAGE_COUNT - 1] = -1 },
.avpnm = 0x1UL,
.tlbiel = 0,
},
};
static unsigned long htab_convert_pte_flags(unsigned long pteflags)
{
unsigned long rflags = pteflags & 0x1fa;
/* _PAGE_EXEC -> NOEXEC */
if ((pteflags & _PAGE_EXEC) == 0)
rflags |= HPTE_R_N;
/* PP bits. PAGE_USER is already PP bit 0x2, so we only
* need to add in 0x1 if it's a read-only user page
*/
if ((pteflags & _PAGE_USER) && !((pteflags & _PAGE_RW) &&
(pteflags & _PAGE_DIRTY)))
rflags |= 1;
/* Always add C */
return rflags | HPTE_R_C;
}
int htab_bolt_mapping(unsigned long vstart, unsigned long vend,
unsigned long pstart, unsigned long prot,
int psize, int ssize)
{
unsigned long vaddr, paddr;
unsigned int step, shift;
int ret = 0;
shift = mmu_psize_defs[psize].shift;
step = 1 << shift;
prot = htab_convert_pte_flags(prot);
DBG("htab_bolt_mapping(%lx..%lx -> %lx (%lx,%d,%d)\n",
vstart, vend, pstart, prot, psize, ssize);
for (vaddr = vstart, paddr = pstart; vaddr < vend;
vaddr += step, paddr += step) {
unsigned long hash, hpteg;
unsigned long vsid = get_kernel_vsid(vaddr, ssize);
unsigned long vpn = hpt_vpn(vaddr, vsid, ssize);
unsigned long tprot = prot;
/*
* If we hit a bad address return error.
*/
if (!vsid)
return -1;
/* Make kernel text executable */
if (overlaps_kernel_text(vaddr, vaddr + step))
tprot &= ~HPTE_R_N;
hash = hpt_hash(vpn, shift, ssize);
hpteg = ((hash & htab_hash_mask) * HPTES_PER_GROUP);
BUG_ON(!ppc_md.hpte_insert);
ret = ppc_md.hpte_insert(hpteg, vpn, paddr, tprot,
HPTE_V_BOLTED, psize, psize, ssize);
if (ret < 0)
break;
#ifdef CONFIG_DEBUG_PAGEALLOC
if ((paddr >> PAGE_SHIFT) < linear_map_hash_count)
linear_map_hash_slots[paddr >> PAGE_SHIFT] = ret | 0x80;
#endif /* CONFIG_DEBUG_PAGEALLOC */
}
return ret < 0 ? ret : 0;
}
#ifdef CONFIG_MEMORY_HOTPLUG
static int htab_remove_mapping(unsigned long vstart, unsigned long vend,
int psize, int ssize)
{
unsigned long vaddr;
unsigned int step, shift;
shift = mmu_psize_defs[psize].shift;
step = 1 << shift;
if (!ppc_md.hpte_removebolted) {
printk(KERN_WARNING "Platform doesn't implement "
"hpte_removebolted\n");
return -EINVAL;
}
for (vaddr = vstart; vaddr < vend; vaddr += step)
ppc_md.hpte_removebolted(vaddr, psize, ssize);
return 0;
}
#endif /* CONFIG_MEMORY_HOTPLUG */
static int __init htab_dt_scan_seg_sizes(unsigned long node,
const char *uname, int depth,
void *data)
{
char *type = of_get_flat_dt_prop(node, "device_type", NULL);
u32 *prop;
unsigned long size = 0;
/* We are scanning "cpu" nodes only */
if (type == NULL || strcmp(type, "cpu") != 0)
return 0;
prop = (u32 *)of_get_flat_dt_prop(node, "ibm,processor-segment-sizes",
&size);
if (prop == NULL)
return 0;
for (; size >= 4; size -= 4, ++prop) {
if (prop[0] == 40) {
DBG("1T segment support detected\n");
cur_cpu_spec->mmu_features |= MMU_FTR_1T_SEGMENT;
return 1;
}
}
cur_cpu_spec->mmu_features &= ~MMU_FTR_NO_SLBIE_B;
return 0;
}
static void __init htab_init_seg_sizes(void)
{
of_scan_flat_dt(htab_dt_scan_seg_sizes, NULL);
}
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 0x14:
idx = MMU_PAGE_1M;
break;
case 0x18:
idx = MMU_PAGE_16M;
break;
case 0x22:
idx = MMU_PAGE_16G;
break;
}
return idx;
}
static int __init htab_dt_scan_page_sizes(unsigned long node,
const char *uname, int depth,
void *data)
{
char *type = of_get_flat_dt_prop(node, "device_type", NULL);
u32 *prop;
unsigned long size = 0;
/* We are scanning "cpu" nodes only */
if (type == NULL || strcmp(type, "cpu") != 0)
return 0;
prop = (u32 *)of_get_flat_dt_prop(node,
"ibm,segment-page-sizes", &size);
if (prop != NULL) {
pr_info("Page sizes from device-tree:\n");
size /= 4;
cur_cpu_spec->mmu_features &= ~(MMU_FTR_16M_PAGE);
while(size > 0) {
unsigned int base_shift = prop[0];
unsigned int slbenc = prop[1];
unsigned int lpnum = prop[2];
struct mmu_psize_def *def;
int idx, base_idx;
size -= 3; prop += 3;
base_idx = get_idx_from_shift(base_shift);
if (base_idx < 0) {
/*
* skip the pte encoding also
*/
prop += lpnum * 2; size -= lpnum * 2;
continue;
}
def = &mmu_psize_defs[base_idx];
if (base_idx == MMU_PAGE_16M)
cur_cpu_spec->mmu_features |= MMU_FTR_16M_PAGE;
def->shift = base_shift;
if (base_shift <= 23)
def->avpnm = 0;
else
def->avpnm = (1 << (base_shift - 23)) - 1;
def->sllp = slbenc;
/*
* We don't know for sure what's up with tlbiel, so
* for now we only set it for 4K and 64K pages
*/
if (base_idx == MMU_PAGE_4K || base_idx == MMU_PAGE_64K)
def->tlbiel = 1;
else
def->tlbiel = 0;
while (size > 0 && lpnum) {
unsigned int shift = prop[0];
int penc = prop[1];
prop += 2; size -= 2;
lpnum--;
idx = get_idx_from_shift(shift);
if (idx < 0)
continue;
if (penc == -1)
pr_err("Invalid penc for base_shift=%d "
"shift=%d\n", base_shift, shift);
def->penc[idx] = penc;
pr_info("base_shift=%d: shift=%d, sllp=0x%04lx,"
" avpnm=0x%08lx, tlbiel=%d, penc=%d\n",
base_shift, shift, def->sllp,
def->avpnm, def->tlbiel, def->penc[idx]);
}
}
return 1;
}
return 0;
}
#ifdef CONFIG_HUGETLB_PAGE
/* Scan for 16G memory blocks that have been set aside for huge pages
* and reserve those blocks for 16G huge pages.
*/
static int __init htab_dt_scan_hugepage_blocks(unsigned long node,
const char *uname, int depth,
void *data) {
char *type = of_get_flat_dt_prop(node, "device_type", NULL);
unsigned long *addr_prop;
u32 *page_count_prop;
unsigned int expected_pages;
long unsigned int phys_addr;
long unsigned int block_size;
/* We are scanning "memory" nodes only */
if (type == NULL || strcmp(type, "memory") != 0)
return 0;
/* This property is the log base 2 of the number of virtual pages that
* will represent this memory block. */
page_count_prop = of_get_flat_dt_prop(node, "ibm,expected#pages", NULL);
if (page_count_prop == NULL)
return 0;
expected_pages = (1 << page_count_prop[0]);
addr_prop = of_get_flat_dt_prop(node, "reg", NULL);
if (addr_prop == NULL)
return 0;
phys_addr = addr_prop[0];
block_size = addr_prop[1];
if (block_size != (16 * GB))
return 0;
printk(KERN_INFO "Huge page(16GB) memory: "
"addr = 0x%lX size = 0x%lX pages = %d\n",
phys_addr, block_size, expected_pages);
if (phys_addr + (16 * GB) <= memblock_end_of_DRAM()) {
memblock_reserve(phys_addr, block_size * expected_pages);
add_gpage(phys_addr, block_size, expected_pages);
}
return 0;
}
#endif /* CONFIG_HUGETLB_PAGE */
static void mmu_psize_set_default_penc(void)
{
int bpsize, apsize;
for (bpsize = 0; bpsize < MMU_PAGE_COUNT; bpsize++)
for (apsize = 0; apsize < MMU_PAGE_COUNT; apsize++)
mmu_psize_defs[bpsize].penc[apsize] = -1;
}
static void __init htab_init_page_sizes(void)
{
int rc;
/* se the invalid penc to -1 */
mmu_psize_set_default_penc();
/* Default to 4K pages only */
memcpy(mmu_psize_defs, mmu_psize_defaults_old,
sizeof(mmu_psize_defaults_old));
/*
* Try to find the available page sizes in the device-tree
*/
rc = of_scan_flat_dt(htab_dt_scan_page_sizes, NULL);
if (rc != 0) /* Found */
goto found;
/*
* Not in the device-tree, let's fallback on known size
* list for 16M capable GP & GR
*/
if (mmu_has_feature(MMU_FTR_16M_PAGE))
memcpy(mmu_psize_defs, mmu_psize_defaults_gp,
sizeof(mmu_psize_defaults_gp));
found:
#ifndef CONFIG_DEBUG_PAGEALLOC
/*
* Pick a size for the linear mapping. Currently, we only support
* 16M, 1M and 4K which is the default
*/
if (mmu_psize_defs[MMU_PAGE_16M].shift)
mmu_linear_psize = MMU_PAGE_16M;
else if (mmu_psize_defs[MMU_PAGE_1M].shift)
mmu_linear_psize = MMU_PAGE_1M;
#endif /* CONFIG_DEBUG_PAGEALLOC */
#ifdef CONFIG_PPC_64K_PAGES
/*
* Pick a size for the ordinary pages. Default is 4K, we support
* 64K for user mappings and vmalloc if supported by the processor.
* We only use 64k for ioremap if the processor
* (and firmware) support cache-inhibited large pages.
* If not, we use 4k and set mmu_ci_restrictions so that
* hash_page knows to switch processes that use cache-inhibited
* mappings to 4k pages.
*/
if (mmu_psize_defs[MMU_PAGE_64K].shift) {
mmu_virtual_psize = MMU_PAGE_64K;
mmu_vmalloc_psize = MMU_PAGE_64K;
if (mmu_linear_psize == MMU_PAGE_4K)
mmu_linear_psize = MMU_PAGE_64K;
if (mmu_has_feature(MMU_FTR_CI_LARGE_PAGE)) {
/*
* Don't use 64k pages for ioremap on pSeries, since
* that would stop us accessing the HEA ethernet.
*/
if (!machine_is(pseries))
mmu_io_psize = MMU_PAGE_64K;
} else
mmu_ci_restrictions = 1;
}
#endif /* CONFIG_PPC_64K_PAGES */
#ifdef CONFIG_SPARSEMEM_VMEMMAP
/* We try to use 16M pages for vmemmap if that is supported
* and we have at least 1G of RAM at boot
*/
if (mmu_psize_defs[MMU_PAGE_16M].shift &&
memblock_phys_mem_size() >= 0x40000000)
mmu_vmemmap_psize = MMU_PAGE_16M;
else if (mmu_psize_defs[MMU_PAGE_64K].shift)
mmu_vmemmap_psize = MMU_PAGE_64K;
else
mmu_vmemmap_psize = MMU_PAGE_4K;
#endif /* CONFIG_SPARSEMEM_VMEMMAP */
printk(KERN_DEBUG "Page orders: linear mapping = %d, "
"virtual = %d, io = %d"
#ifdef CONFIG_SPARSEMEM_VMEMMAP
", vmemmap = %d"
#endif
"\n",
mmu_psize_defs[mmu_linear_psize].shift,
mmu_psize_defs[mmu_virtual_psize].shift,
mmu_psize_defs[mmu_io_psize].shift
#ifdef CONFIG_SPARSEMEM_VMEMMAP
,mmu_psize_defs[mmu_vmemmap_psize].shift
#endif
);
#ifdef CONFIG_HUGETLB_PAGE
/* Reserve 16G huge page memory sections for huge pages */
of_scan_flat_dt(htab_dt_scan_hugepage_blocks, NULL);
#endif /* CONFIG_HUGETLB_PAGE */
}
static int __init htab_dt_scan_pftsize(unsigned long node,
const char *uname, int depth,
void *data)
{
char *type = of_get_flat_dt_prop(node, "device_type", NULL);
u32 *prop;
/* We are scanning "cpu" nodes only */
if (type == NULL || strcmp(type, "cpu") != 0)
return 0;
prop = (u32 *)of_get_flat_dt_prop(node, "ibm,pft-size", NULL);
if (prop != NULL) {
/* pft_size[0] is the NUMA CEC cookie */
ppc64_pft_size = prop[1];
return 1;
}
return 0;
}
static unsigned long __init htab_get_table_size(void)
{
unsigned long mem_size, rnd_mem_size, pteg_count, psize;
/* If hash size isn't already provided by the platform, we try to
* retrieve it from the device-tree. If it's not there neither, we
* calculate it now based on the total RAM size
*/
if (ppc64_pft_size == 0)
of_scan_flat_dt(htab_dt_scan_pftsize, NULL);
if (ppc64_pft_size)
return 1UL << ppc64_pft_size;
/* round mem_size up to next power of 2 */
mem_size = memblock_phys_mem_size();
rnd_mem_size = 1UL << __ilog2(mem_size);
if (rnd_mem_size < mem_size)
rnd_mem_size <<= 1;
/* # pages / 2 */
psize = mmu_psize_defs[mmu_virtual_psize].shift;
pteg_count = max(rnd_mem_size >> (psize + 1), 1UL << 11);
return pteg_count << 7;
}
#ifdef CONFIG_MEMORY_HOTPLUG
int create_section_mapping(unsigned long start, unsigned long end)
{
return htab_bolt_mapping(start, end, __pa(start),
pgprot_val(PAGE_KERNEL), mmu_linear_psize,
mmu_kernel_ssize);
}
int remove_section_mapping(unsigned long start, unsigned long end)
{
return htab_remove_mapping(start, end, mmu_linear_psize,
mmu_kernel_ssize);
}
#endif /* CONFIG_MEMORY_HOTPLUG */
#define FUNCTION_TEXT(A) ((*(unsigned long *)(A)))
static void __init htab_finish_init(void)
{
extern unsigned int *htab_call_hpte_insert1;
extern unsigned int *htab_call_hpte_insert2;
extern unsigned int *htab_call_hpte_remove;
extern unsigned int *htab_call_hpte_updatepp;
#ifdef CONFIG_PPC_HAS_HASH_64K
extern unsigned int *ht64_call_hpte_insert1;
extern unsigned int *ht64_call_hpte_insert2;
extern unsigned int *ht64_call_hpte_remove;
extern unsigned int *ht64_call_hpte_updatepp;
patch_branch(ht64_call_hpte_insert1,
FUNCTION_TEXT(ppc_md.hpte_insert),
BRANCH_SET_LINK);
patch_branch(ht64_call_hpte_insert2,
FUNCTION_TEXT(ppc_md.hpte_insert),
BRANCH_SET_LINK);
patch_branch(ht64_call_hpte_remove,
FUNCTION_TEXT(ppc_md.hpte_remove),
BRANCH_SET_LINK);
patch_branch(ht64_call_hpte_updatepp,
FUNCTION_TEXT(ppc_md.hpte_updatepp),
BRANCH_SET_LINK);
#endif /* CONFIG_PPC_HAS_HASH_64K */
patch_branch(htab_call_hpte_insert1,
FUNCTION_TEXT(ppc_md.hpte_insert),
BRANCH_SET_LINK);
patch_branch(htab_call_hpte_insert2,
FUNCTION_TEXT(ppc_md.hpte_insert),
BRANCH_SET_LINK);
patch_branch(htab_call_hpte_remove,
FUNCTION_TEXT(ppc_md.hpte_remove),
BRANCH_SET_LINK);
patch_branch(htab_call_hpte_updatepp,
FUNCTION_TEXT(ppc_md.hpte_updatepp),
BRANCH_SET_LINK);
}
static void __init htab_initialize(void)
{
unsigned long table;
unsigned long pteg_count;
unsigned long prot;
unsigned long base = 0, size = 0, limit;
struct memblock_region *reg;
DBG(" -> htab_initialize()\n");
/* Initialize segment sizes */
htab_init_seg_sizes();
/* Initialize page sizes */
htab_init_page_sizes();
if (mmu_has_feature(MMU_FTR_1T_SEGMENT)) {
mmu_kernel_ssize = MMU_SEGSIZE_1T;
mmu_highuser_ssize = MMU_SEGSIZE_1T;
printk(KERN_INFO "Using 1TB segments\n");
}
/*
* Calculate the required size of the htab. We want the number of
* PTEGs to equal one half the number of real pages.
*/
htab_size_bytes = htab_get_table_size();
pteg_count = htab_size_bytes >> 7;
htab_hash_mask = pteg_count - 1;
if (firmware_has_feature(FW_FEATURE_LPAR)) {
/* Using a hypervisor which owns the htab */
htab_address = NULL;
_SDR1 = 0;
#ifdef CONFIG_FA_DUMP
/*
* If firmware assisted dump is active firmware preserves
* the contents of htab along with entire partition memory.
* Clear the htab if firmware assisted dump is active so
* that we dont end up using old mappings.
*/
if (is_fadump_active() && ppc_md.hpte_clear_all)
ppc_md.hpte_clear_all();
#endif
} else {
/* Find storage for the HPT. Must be contiguous in
* the absolute address space. On cell we want it to be
* in the first 2 Gig so we can use it for IOMMU hacks.
*/
if (machine_is(cell))
limit = 0x80000000;
else
limit = MEMBLOCK_ALLOC_ANYWHERE;
table = memblock_alloc_base(htab_size_bytes, htab_size_bytes, limit);
DBG("Hash table allocated at %lx, size: %lx\n", table,
htab_size_bytes);
htab_address = __va(table);
/* htab absolute addr + encoded htabsize */
_SDR1 = table + __ilog2(pteg_count) - 11;
/* Initialize the HPT with no entries */
memset((void *)table, 0, htab_size_bytes);
/* Set SDR1 */
mtspr(SPRN_SDR1, _SDR1);
}
prot = pgprot_val(PAGE_KERNEL);
#ifdef CONFIG_DEBUG_PAGEALLOC
linear_map_hash_count = memblock_end_of_DRAM() >> PAGE_SHIFT;
linear_map_hash_slots = __va(memblock_alloc_base(linear_map_hash_count,
1, ppc64_rma_size));
memset(linear_map_hash_slots, 0, linear_map_hash_count);
#endif /* CONFIG_DEBUG_PAGEALLOC */
/* On U3 based machines, we need to reserve the DART area and
* _NOT_ map it to avoid cache paradoxes as it's remapped non
* cacheable later on
*/
/* create bolted the linear mapping in the hash table */
for_each_memblock(memory, reg) {
base = (unsigned long)__va(reg->base);
size = reg->size;
DBG("creating mapping for region: %lx..%lx (prot: %lx)\n",
base, size, prot);
#ifdef CONFIG_U3_DART
/* Do not map the DART space. Fortunately, it will be aligned
* in such a way that it will not cross two memblock regions and
* will fit within a single 16Mb page.
* The DART space is assumed to be a full 16Mb region even if
* we only use 2Mb of that space. We will use more of it later
* for AGP GART. We have to use a full 16Mb large page.
*/
DBG("DART base: %lx\n", dart_tablebase);
if (dart_tablebase != 0 && dart_tablebase >= base
&& dart_tablebase < (base + size)) {
unsigned long dart_table_end = dart_tablebase + 16 * MB;
if (base != dart_tablebase)
BUG_ON(htab_bolt_mapping(base, dart_tablebase,
__pa(base), prot,
mmu_linear_psize,
mmu_kernel_ssize));
if ((base + size) > dart_table_end)
BUG_ON(htab_bolt_mapping(dart_tablebase+16*MB,
base + size,
__pa(dart_table_end),
prot,
mmu_linear_psize,
mmu_kernel_ssize));
continue;
}
#endif /* CONFIG_U3_DART */
BUG_ON(htab_bolt_mapping(base, base + size, __pa(base),
prot, mmu_linear_psize, mmu_kernel_ssize));
}
memblock_set_current_limit(MEMBLOCK_ALLOC_ANYWHERE);
/*
* If we have a memory_limit and we've allocated TCEs then we need to
* explicitly map the TCE area at the top of RAM. We also cope with the
* case that the TCEs start below memory_limit.
* tce_alloc_start/end are 16MB aligned so the mapping should work
* for either 4K or 16MB pages.
*/
if (tce_alloc_start) {
tce_alloc_start = (unsigned long)__va(tce_alloc_start);
tce_alloc_end = (unsigned long)__va(tce_alloc_end);
if (base + size >= tce_alloc_start)
tce_alloc_start = base + size + 1;
BUG_ON(htab_bolt_mapping(tce_alloc_start, tce_alloc_end,
__pa(tce_alloc_start), prot,
mmu_linear_psize, mmu_kernel_ssize));
}
htab_finish_init();
DBG(" <- htab_initialize()\n");
}
#undef KB
#undef MB
void __init early_init_mmu(void)
{
/* Setup initial STAB address in the PACA */
get_paca()->stab_real = __pa((u64)&initial_stab);
get_paca()->stab_addr = (u64)&initial_stab;
/* Initialize the MMU Hash table and create the linear mapping
* of memory. Has to be done before stab/slb initialization as
* this is currently where the page size encoding is obtained
*/
htab_initialize();
/* Initialize stab / SLB management */
if (mmu_has_feature(MMU_FTR_SLB))
slb_initialize();
else
stab_initialize(get_paca()->stab_real);
}
#ifdef CONFIG_SMP
void __cpuinit early_init_mmu_secondary(void)
{
/* Initialize hash table for that CPU */
if (!firmware_has_feature(FW_FEATURE_LPAR))
mtspr(SPRN_SDR1, _SDR1);
/* Initialize STAB/SLB. We use a virtual address as it works
* in real mode on pSeries.
*/
if (mmu_has_feature(MMU_FTR_SLB))
slb_initialize();
else
stab_initialize(get_paca()->stab_addr);
}
#endif /* CONFIG_SMP */
/*
* Called by asm hashtable.S for doing lazy icache flush
*/
unsigned int hash_page_do_lazy_icache(unsigned int pp, pte_t pte, int trap)
{
struct page *page;
if (!pfn_valid(pte_pfn(pte)))
return pp;
page = pte_page(pte);
/* page is dirty */
if (!test_bit(PG_arch_1, &page->flags) && !PageReserved(page)) {
if (trap == 0x400) {
flush_dcache_icache_page(page);
set_bit(PG_arch_1, &page->flags);
} else
pp |= HPTE_R_N;
}
return pp;
}
#ifdef CONFIG_PPC_MM_SLICES
unsigned int get_paca_psize(unsigned long addr)
{
u64 lpsizes;
unsigned char *hpsizes;
unsigned long index, mask_index;
if (addr < SLICE_LOW_TOP) {
lpsizes = get_paca()->context.low_slices_psize;
index = GET_LOW_SLICE_INDEX(addr);
return (lpsizes >> (index * 4)) & 0xF;
}
hpsizes = get_paca()->context.high_slices_psize;
index = GET_HIGH_SLICE_INDEX(addr);
mask_index = index & 0x1;
return (hpsizes[index >> 1] >> (mask_index * 4)) & 0xF;
}
#else
unsigned int get_paca_psize(unsigned long addr)
{
return get_paca()->context.user_psize;
}
#endif
/*
* Demote a segment to using 4k pages.
* For now this makes the whole process use 4k pages.
*/
#ifdef CONFIG_PPC_64K_PAGES
void demote_segment_4k(struct mm_struct *mm, unsigned long addr)
{
if (get_slice_psize(mm, addr) == MMU_PAGE_4K)
return;
slice_set_range_psize(mm, addr, 1, MMU_PAGE_4K);
#ifdef CONFIG_SPU_BASE
spu_flush_all_slbs(mm);
#endif
if (get_paca_psize(addr) != MMU_PAGE_4K) {
get_paca()->context = mm->context;
slb_flush_and_rebolt();
}
}
#endif /* CONFIG_PPC_64K_PAGES */
#ifdef CONFIG_PPC_SUBPAGE_PROT
/*
* This looks up a 2-bit protection code for a 4k subpage of a 64k page.
* Userspace sets the subpage permissions using the subpage_prot system call.
*
* Result is 0: full permissions, _PAGE_RW: read-only,
* _PAGE_USER or _PAGE_USER|_PAGE_RW: no access.
*/
static int subpage_protection(struct mm_struct *mm, unsigned long ea)
{
struct subpage_prot_table *spt = &mm->context.spt;
u32 spp = 0;
u32 **sbpm, *sbpp;
if (ea >= spt->maxaddr)
return 0;
if (ea < 0x100000000) {
/* addresses below 4GB use spt->low_prot */
sbpm = spt->low_prot;
} else {
sbpm = spt->protptrs[ea >> SBP_L3_SHIFT];
if (!sbpm)
return 0;
}
sbpp = sbpm[(ea >> SBP_L2_SHIFT) & (SBP_L2_COUNT - 1)];
if (!sbpp)
return 0;
spp = sbpp[(ea >> PAGE_SHIFT) & (SBP_L1_COUNT - 1)];
/* extract 2-bit bitfield for this 4k subpage */
spp >>= 30 - 2 * ((ea >> 12) & 0xf);
/* turn 0,1,2,3 into combination of _PAGE_USER and _PAGE_RW */
spp = ((spp & 2) ? _PAGE_USER : 0) | ((spp & 1) ? _PAGE_RW : 0);
return spp;
}
#else /* CONFIG_PPC_SUBPAGE_PROT */
static inline int subpage_protection(struct mm_struct *mm, unsigned long ea)
{
return 0;
}
#endif
void hash_failure_debug(unsigned long ea, unsigned long access,
unsigned long vsid, unsigned long trap,
int ssize, int psize, int lpsize, unsigned long pte)
{
if (!printk_ratelimit())
return;
pr_info("mm: Hashing failure ! EA=0x%lx access=0x%lx current=%s\n",
ea, access, current->comm);
pr_info(" trap=0x%lx vsid=0x%lx ssize=%d base psize=%d psize %d pte=0x%lx\n",
trap, vsid, ssize, psize, lpsize, pte);
}
/* Result code is:
* 0 - handled
* 1 - normal page fault
* -1 - critical hash insertion error
* -2 - access not permitted by subpage protection mechanism
*/
int hash_page(unsigned long ea, unsigned long access, unsigned long trap)
{
enum ctx_state prev_state = exception_enter();
pgd_t *pgdir;
unsigned long vsid;
struct mm_struct *mm;
pte_t *ptep;
unsigned hugeshift;
const struct cpumask *tmp;
int rc, user_region = 0, local = 0;
int psize, ssize;
DBG_LOW("hash_page(ea=%016lx, access=%lx, trap=%lx\n",
ea, access, trap);
/* Get region & vsid */
switch (REGION_ID(ea)) {
case USER_REGION_ID:
user_region = 1;
mm = current->mm;
if (! mm) {
DBG_LOW(" user region with no mm !\n");
rc = 1;
goto bail;
}
psize = get_slice_psize(mm, ea);
ssize = user_segment_size(ea);
vsid = get_vsid(mm->context.id, ea, ssize);
break;
case VMALLOC_REGION_ID:
mm = &init_mm;
vsid = get_kernel_vsid(ea, mmu_kernel_ssize);
if (ea < VMALLOC_END)
psize = mmu_vmalloc_psize;
else
psize = mmu_io_psize;
ssize = mmu_kernel_ssize;
break;
default:
/* Not a valid range
* Send the problem up to do_page_fault
*/
rc = 1;
goto bail;
}
DBG_LOW(" mm=%p, mm->pgdir=%p, vsid=%016lx\n", mm, mm->pgd, vsid);
/* Bad address. */
if (!vsid) {
DBG_LOW("Bad address!\n");
rc = 1;
goto bail;
}
/* Get pgdir */
pgdir = mm->pgd;
if (pgdir == NULL) {
rc = 1;
goto bail;
}
/* Check CPU locality */
tmp = cpumask_of(smp_processor_id());
if (user_region && cpumask_equal(mm_cpumask(mm), tmp))
local = 1;
#ifndef CONFIG_PPC_64K_PAGES
/* If we use 4K pages and our psize is not 4K, then we might
* be hitting a special driver mapping, and need to align the
* address before we fetch the PTE.
*
* It could also be a hugepage mapping, in which case this is
* not necessary, but it's not harmful, either.
*/
if (psize != MMU_PAGE_4K)
ea &= ~((1ul << mmu_psize_defs[psize].shift) - 1);
#endif /* CONFIG_PPC_64K_PAGES */
/* Get PTE and page size from page tables */
ptep = find_linux_pte_or_hugepte(pgdir, ea, &hugeshift);
if (ptep == NULL || !pte_present(*ptep)) {
DBG_LOW(" no PTE !\n");
rc = 1;
goto bail;
}
/* Add _PAGE_PRESENT to the required access perm */
access |= _PAGE_PRESENT;
/* Pre-check access permissions (will be re-checked atomically
* in __hash_page_XX but this pre-check is a fast path
*/
if (access & ~pte_val(*ptep)) {
DBG_LOW(" no access !\n");
rc = 1;
goto bail;
}
if (hugeshift) {
if (pmd_trans_huge(*(pmd_t *)ptep))
rc = __hash_page_thp(ea, access, vsid, (pmd_t *)ptep,
trap, local, ssize, psize);
#ifdef CONFIG_HUGETLB_PAGE
else
rc = __hash_page_huge(ea, access, vsid, ptep, trap,
local, ssize, hugeshift, psize);
#else
else {
/*
* if we have hugeshift, and is not transhuge with
* hugetlb disabled, something is really wrong.
*/
rc = 1;
WARN_ON(1);
}
#endif
goto bail;
}
#ifndef CONFIG_PPC_64K_PAGES
DBG_LOW(" i-pte: %016lx\n", pte_val(*ptep));
#else
DBG_LOW(" i-pte: %016lx %016lx\n", pte_val(*ptep),
pte_val(*(ptep + PTRS_PER_PTE)));
#endif
/* Do actual hashing */
#ifdef CONFIG_PPC_64K_PAGES
/* If _PAGE_4K_PFN is set, make sure this is a 4k segment */
if ((pte_val(*ptep) & _PAGE_4K_PFN) && psize == MMU_PAGE_64K) {
demote_segment_4k(mm, ea);
psize = MMU_PAGE_4K;
}
/* If this PTE is non-cacheable and we have restrictions on
* using non cacheable large pages, then we switch to 4k
*/
if (mmu_ci_restrictions && psize == MMU_PAGE_64K &&
(pte_val(*ptep) & _PAGE_NO_CACHE)) {
if (user_region) {
demote_segment_4k(mm, ea);
psize = MMU_PAGE_4K;
} else if (ea < VMALLOC_END) {
/*
* some driver did a non-cacheable mapping
* in vmalloc space, so switch vmalloc
* to 4k pages
*/
printk(KERN_ALERT "Reducing vmalloc segment "
"to 4kB pages because of "
"non-cacheable mapping\n");
psize = mmu_vmalloc_psize = MMU_PAGE_4K;
#ifdef CONFIG_SPU_BASE
spu_flush_all_slbs(mm);
#endif
}
}
if (user_region) {
if (psize != get_paca_psize(ea)) {
get_paca()->context = mm->context;
slb_flush_and_rebolt();
}
} else if (get_paca()->vmalloc_sllp !=
mmu_psize_defs[mmu_vmalloc_psize].sllp) {
get_paca()->vmalloc_sllp =
mmu_psize_defs[mmu_vmalloc_psize].sllp;
slb_vmalloc_update();
}
#endif /* CONFIG_PPC_64K_PAGES */
#ifdef CONFIG_PPC_HAS_HASH_64K
if (psize == MMU_PAGE_64K)
rc = __hash_page_64K(ea, access, vsid, ptep, trap, local, ssize);
else
#endif /* CONFIG_PPC_HAS_HASH_64K */
{
int spp = subpage_protection(mm, ea);
if (access & spp)
rc = -2;
else
rc = __hash_page_4K(ea, access, vsid, ptep, trap,
local, ssize, spp);
}
/* Dump some info in case of hash insertion failure, they should
* never happen so it is really useful to know if/when they do
*/
if (rc == -1)
hash_failure_debug(ea, access, vsid, trap, ssize, psize,
psize, pte_val(*ptep));
#ifndef CONFIG_PPC_64K_PAGES
DBG_LOW(" o-pte: %016lx\n", pte_val(*ptep));
#else
DBG_LOW(" o-pte: %016lx %016lx\n", pte_val(*ptep),
pte_val(*(ptep + PTRS_PER_PTE)));
#endif
DBG_LOW(" -> rc=%d\n", rc);
bail:
exception_exit(prev_state);
return rc;
}
EXPORT_SYMBOL_GPL(hash_page);
void hash_preload(struct mm_struct *mm, unsigned long ea,
unsigned long access, unsigned long trap)
{
int hugepage_shift;
unsigned long vsid;
pgd_t *pgdir;
pte_t *ptep;
unsigned long flags;
int rc, ssize, local = 0;
BUG_ON(REGION_ID(ea) != USER_REGION_ID);
#ifdef CONFIG_PPC_MM_SLICES
/* We only prefault standard pages for now */
if (unlikely(get_slice_psize(mm, ea) != mm->context.user_psize))
return;
#endif
DBG_LOW("hash_preload(mm=%p, mm->pgdir=%p, ea=%016lx, access=%lx,"
" trap=%lx\n", mm, mm->pgd, ea, access, trap);
/* Get Linux PTE if available */
pgdir = mm->pgd;
if (pgdir == NULL)
return;
/* Get VSID */
ssize = user_segment_size(ea);
vsid = get_vsid(mm->context.id, ea, ssize);
if (!vsid)
return;
/*
* Hash doesn't like irqs. Walking linux page table with irq disabled
* saves us from holding multiple locks.
*/
local_irq_save(flags);
/*
* THP pages use update_mmu_cache_pmd. We don't do
* hash preload there. Hence can ignore THP here
*/
ptep = find_linux_pte_or_hugepte(pgdir, ea, &hugepage_shift);
if (!ptep)
goto out_exit;
WARN_ON(hugepage_shift);
#ifdef CONFIG_PPC_64K_PAGES
/* If either _PAGE_4K_PFN or _PAGE_NO_CACHE is set (and we are on
* a 64K kernel), then we don't preload, hash_page() will take
* care of it once we actually try to access the page.
* That way we don't have to duplicate all of the logic for segment
* page size demotion here
*/
if (pte_val(*ptep) & (_PAGE_4K_PFN | _PAGE_NO_CACHE))
goto out_exit;
#endif /* CONFIG_PPC_64K_PAGES */
/* Is that local to this CPU ? */
if (cpumask_equal(mm_cpumask(mm), cpumask_of(smp_processor_id())))
local = 1;
/* Hash it in */
#ifdef CONFIG_PPC_HAS_HASH_64K
if (mm->context.user_psize == MMU_PAGE_64K)
rc = __hash_page_64K(ea, access, vsid, ptep, trap, local, ssize);
else
#endif /* CONFIG_PPC_HAS_HASH_64K */
rc = __hash_page_4K(ea, access, vsid, ptep, trap, local, ssize,
subpage_protection(mm, ea));
/* Dump some info in case of hash insertion failure, they should
* never happen so it is really useful to know if/when they do
*/
if (rc == -1)
hash_failure_debug(ea, access, vsid, trap, ssize,
mm->context.user_psize,
mm->context.user_psize,
pte_val(*ptep));
out_exit:
local_irq_restore(flags);
}
/* WARNING: This is called from hash_low_64.S, if you change this prototype,
* do not forget to update the assembly call site !
*/
void flush_hash_page(unsigned long vpn, real_pte_t pte, int psize, int ssize,
int local)
{
unsigned long hash, index, shift, hidx, slot;
DBG_LOW("flush_hash_page(vpn=%016lx)\n", vpn);
pte_iterate_hashed_subpages(pte, psize, vpn, index, shift) {
hash = hpt_hash(vpn, shift, ssize);
hidx = __rpte_to_hidx(pte, index);
if (hidx & _PTEIDX_SECONDARY)
hash = ~hash;
slot = (hash & htab_hash_mask) * HPTES_PER_GROUP;
slot += hidx & _PTEIDX_GROUP_IX;
DBG_LOW(" sub %ld: hash=%lx, hidx=%lx\n", index, slot, hidx);
/*
* We use same base page size and actual psize, because we don't
* use these functions for hugepage
*/
ppc_md.hpte_invalidate(slot, vpn, psize, psize, ssize, local);
} pte_iterate_hashed_end();
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
/* Transactions are not aborted by tlbiel, only tlbie.
* Without, syncing a page back to a block device w/ PIO could pick up
* transactional data (bad!) so we force an abort here. Before the
* sync the page will be made read-only, which will flush_hash_page.
* BIG ISSUE here: if the kernel uses a page from userspace without
* unmapping it first, it may see the speculated version.
*/
if (local && cpu_has_feature(CPU_FTR_TM) &&
current->thread.regs &&
MSR_TM_ACTIVE(current->thread.regs->msr)) {
tm_enable();
tm_abort(TM_CAUSE_TLBI);
}
#endif
}
void flush_hash_range(unsigned long number, int local)
{
if (ppc_md.flush_hash_range)
ppc_md.flush_hash_range(number, local);
else {
int i;
struct ppc64_tlb_batch *batch =
&__get_cpu_var(ppc64_tlb_batch);
for (i = 0; i < number; i++)
flush_hash_page(batch->vpn[i], batch->pte[i],
batch->psize, batch->ssize, local);
}
}
/*
* low_hash_fault is called when we the low level hash code failed
* to instert a PTE due to an hypervisor error
*/
void low_hash_fault(struct pt_regs *regs, unsigned long address, int rc)
{
enum ctx_state prev_state = exception_enter();
if (user_mode(regs)) {
#ifdef CONFIG_PPC_SUBPAGE_PROT
if (rc == -2)
_exception(SIGSEGV, regs, SEGV_ACCERR, address);
else
#endif
_exception(SIGBUS, regs, BUS_ADRERR, address);
} else
bad_page_fault(regs, address, SIGBUS);
exception_exit(prev_state);
}
long hpte_insert_repeating(unsigned long hash, unsigned long vpn,
unsigned long pa, unsigned long rflags,
unsigned long vflags, int psize, int ssize)
{
unsigned long hpte_group;
long slot;
repeat:
hpte_group = ((hash & htab_hash_mask) *
HPTES_PER_GROUP) & ~0x7UL;
/* Insert into the hash table, primary slot */
slot = ppc_md.hpte_insert(hpte_group, vpn, pa, rflags, vflags,
psize, psize, ssize);
/* Primary is full, try the secondary */
if (unlikely(slot == -1)) {
hpte_group = ((~hash & htab_hash_mask) *
HPTES_PER_GROUP) & ~0x7UL;
slot = ppc_md.hpte_insert(hpte_group, vpn, pa, rflags,
vflags | HPTE_V_SECONDARY,
psize, psize, ssize);
if (slot == -1) {
if (mftb() & 0x1)
hpte_group = ((hash & htab_hash_mask) *
HPTES_PER_GROUP)&~0x7UL;
ppc_md.hpte_remove(hpte_group);
goto repeat;
}
}
return slot;
}
#ifdef CONFIG_DEBUG_PAGEALLOC
static void kernel_map_linear_page(unsigned long vaddr, unsigned long lmi)
{
unsigned long hash;
unsigned long vsid = get_kernel_vsid(vaddr, mmu_kernel_ssize);
unsigned long vpn = hpt_vpn(vaddr, vsid, mmu_kernel_ssize);
unsigned long mode = htab_convert_pte_flags(PAGE_KERNEL);
long ret;
hash = hpt_hash(vpn, PAGE_SHIFT, mmu_kernel_ssize);
/* Don't create HPTE entries for bad address */
if (!vsid)
return;
ret = hpte_insert_repeating(hash, vpn, __pa(vaddr), mode,
HPTE_V_BOLTED,
mmu_linear_psize, mmu_kernel_ssize);
BUG_ON (ret < 0);
spin_lock(&linear_map_hash_lock);
BUG_ON(linear_map_hash_slots[lmi] & 0x80);
linear_map_hash_slots[lmi] = ret | 0x80;
spin_unlock(&linear_map_hash_lock);
}
static void kernel_unmap_linear_page(unsigned long vaddr, unsigned long lmi)
{
unsigned long hash, hidx, slot;
unsigned long vsid = get_kernel_vsid(vaddr, mmu_kernel_ssize);
unsigned long vpn = hpt_vpn(vaddr, vsid, mmu_kernel_ssize);
hash = hpt_hash(vpn, PAGE_SHIFT, mmu_kernel_ssize);
spin_lock(&linear_map_hash_lock);
BUG_ON(!(linear_map_hash_slots[lmi] & 0x80));
hidx = linear_map_hash_slots[lmi] & 0x7f;
linear_map_hash_slots[lmi] = 0;
spin_unlock(&linear_map_hash_lock);
if (hidx & _PTEIDX_SECONDARY)
hash = ~hash;
slot = (hash & htab_hash_mask) * HPTES_PER_GROUP;
slot += hidx & _PTEIDX_GROUP_IX;
ppc_md.hpte_invalidate(slot, vpn, mmu_linear_psize, mmu_linear_psize,
mmu_kernel_ssize, 0);
}
void kernel_map_pages(struct page *page, int numpages, int enable)
{
unsigned long flags, vaddr, lmi;
int i;
local_irq_save(flags);
for (i = 0; i < numpages; i++, page++) {
vaddr = (unsigned long)page_address(page);
lmi = __pa(vaddr) >> PAGE_SHIFT;
if (lmi >= linear_map_hash_count)
continue;
if (enable)
kernel_map_linear_page(vaddr, lmi);
else
kernel_unmap_linear_page(vaddr, lmi);
}
local_irq_restore(flags);
}
#endif /* CONFIG_DEBUG_PAGEALLOC */
void 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);
/* On LPAR systems, the first entry is our RMA region,
* non-LPAR 64-bit hash MMU systems don't have a limitation
* on real mode access, but using the first entry works well
* enough. We also clamp it to 1G to avoid some funky things
* such as RTAS bugs etc...
*/
ppc64_rma_size = min_t(u64, first_memblock_size, 0x40000000);
/* Finally limit subsequent allocations */
memblock_set_current_limit(ppc64_rma_size);
}
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