/*
* 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
#include <linux/config.h>
#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/ctype.h>
#include <linux/cache.h>
#include <linux/init.h>
#include <linux/signal.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/system.h>
#include <asm/uaccess.h>
#include <asm/machdep.h>
#include <asm/lmb.h>
#include <asm/abs_addr.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/abs_addr.h>
#include <asm/sections.h>
#ifdef DEBUG
#define DBG(fmt...) udbg_printf(fmt)
#else
#define DBG(fmt...)
#endif
/*
* 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 */
hpte_t *htab_address;
unsigned long htab_hash_mask;
unsigned long _SDR1;
#define KB (1024)
#define MB (1024*KB)
static inline void loop_forever(void)
{
volatile unsigned long x = 1;
for(;x;x|=1)
;
}
static inline void create_pte_mapping(unsigned long start, unsigned long end,
unsigned long mode, int large)
{
unsigned long addr;
unsigned int step;
unsigned long tmp_mode;
unsigned long vflags;
if (large) {
step = 16*MB;
vflags = HPTE_V_BOLTED | HPTE_V_LARGE;
} else {
step = 4*KB;
vflags = HPTE_V_BOLTED;
}
for (addr = start; addr < end; addr += step) {
unsigned long vpn, hash, hpteg;
unsigned long vsid = get_kernel_vsid(addr);
unsigned long va = (vsid << 28) | (addr & 0xfffffff);
int ret = -1;
if (large)
vpn = va >> HPAGE_SHIFT;
else
vpn = va >> PAGE_SHIFT;
tmp_mode = mode;
/* Make non-kernel text non-executable */
if (!in_kernel_text(addr))
tmp_mode = mode | HW_NO_EXEC;
hash = hpt_hash(vpn, large);
hpteg = ((hash & htab_hash_mask) * HPTES_PER_GROUP);
#ifdef CONFIG_PPC_ISERIES
if (systemcfg->platform & PLATFORM_ISERIES_LPAR)
ret = iSeries_hpte_bolt_or_insert(hpteg, va,
virt_to_abs(addr) >> PAGE_SHIFT,
vflags, tmp_mode);
else
#endif
#ifdef CONFIG_PPC_PSERIES
if (systemcfg->platform & PLATFORM_LPAR)
ret = pSeries_lpar_hpte_insert(hpteg, va,
virt_to_abs(addr) >> PAGE_SHIFT,
vflags, tmp_mode);
else
#endif
#ifdef CONFIG_PPC_MULTIPLATFORM
ret = native_hpte_insert(hpteg, va,
virt_to_abs(addr) >> PAGE_SHIFT,
vflags, tmp_mode);
#endif
if (ret == -1) {
ppc64_terminate_msg(0x20, "create_pte_mapping");
loop_forever();
}
}
}
static unsigned long get_hashtable_size(void)
{
unsigned long rnd_mem_size, pteg_count;
/* If hash size wasn't obtained in prom.c, we calculate it now based on
* the total RAM size
*/
if (ppc64_pft_size)
return 1UL << ppc64_pft_size;
/* round mem_size up to next power of 2 */
rnd_mem_size = 1UL << __ilog2(systemcfg->physicalMemorySize);
if (rnd_mem_size < systemcfg->physicalMemorySize)
rnd_mem_size <<= 1;
/* # pages / 2 */
pteg_count = max(rnd_mem_size >> (12 + 1), 1UL << 11);
return pteg_count << 7;
}
void __init htab_initialize(void)
{
unsigned long table, htab_size_bytes;
unsigned long pteg_count;
unsigned long mode_rw;
int i, use_largepages = 0;
unsigned long base = 0, size = 0;
extern unsigned long tce_alloc_start, tce_alloc_end;
DBG(" -> htab_initialize()\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 = get_hashtable_size();
pteg_count = htab_size_bytes >> 7;
htab_hash_mask = pteg_count - 1;
if (systemcfg->platform & PLATFORM_LPAR) {
/* Using a hypervisor which owns the htab */
htab_address = NULL;
_SDR1 = 0;
} else {
/* Find storage for the HPT. Must be contiguous in
* the absolute address space.
*/
table = lmb_alloc(htab_size_bytes, htab_size_bytes);
DBG("Hash table allocated at %lx, size: %lx\n", table,
htab_size_bytes);
if ( !table ) {
ppc64_terminate_msg(0x20, "hpt space");
loop_forever();
}
htab_address = abs_to_virt(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);
}
mode_rw = _PAGE_ACCESSED | _PAGE_DIRTY | _PAGE_COHERENT | PP_RWXX;
/* 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
*/
if (cpu_has_feature(CPU_FTR_16M_PAGE))
use_largepages = 1;
/* create bolted the linear mapping in the hash table */
for (i=0; i < lmb.memory.cnt; i++) {
base = lmb.memory.region[i].base + KERNELBASE;
size = lmb.memory.region[i].size;
DBG("creating mapping for region: %lx : %lx\n", base, size);
#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 lmb 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)) {
if (base != dart_tablebase)
create_pte_mapping(base, dart_tablebase, mode_rw,
use_largepages);
if ((base + size) > (dart_tablebase + 16*MB))
create_pte_mapping(dart_tablebase + 16*MB, base + size,
mode_rw, use_largepages);
continue;
}
#endif /* CONFIG_U3_DART */
create_pte_mapping(base, base + size, mode_rw, use_largepages);
}
/*
* 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 += KERNELBASE;
tce_alloc_end += KERNELBASE;
if (base + size >= tce_alloc_start)
tce_alloc_start = base + size + 1;
create_pte_mapping(tce_alloc_start, tce_alloc_end,
mode_rw, use_largepages);
}
DBG(" <- htab_initialize()\n");
}
#undef KB
#undef MB
/*
* 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_address(page));
set_bit(PG_arch_1, &page->flags);
} else
pp |= HW_NO_EXEC;
}
return pp;
}
/* Result code is:
* 0 - handled
* 1 - normal page fault
* -1 - critical hash insertion error
*/
int hash_page(unsigned long ea, unsigned long access, unsigned long trap)
{
void *pgdir;
unsigned long vsid;
struct mm_struct *mm;
pte_t *ptep;
int ret;
int user_region = 0;
int local = 0;
cpumask_t tmp;
if ((ea & ~REGION_MASK) >= PGTABLE_RANGE)
return 1;
switch (REGION_ID(ea)) {
case USER_REGION_ID:
user_region = 1;
mm = current->mm;
if (! mm)
return 1;
vsid = get_vsid(mm->context.id, ea);
break;
case VMALLOC_REGION_ID:
mm = &init_mm;
vsid = get_kernel_vsid(ea);
break;
#if 0
case KERNEL_REGION_ID:
/*
* Should never get here - entire 0xC0... region is bolted.
* Send the problem up to do_page_fault
*/
#endif
default:
/* Not a valid range
* Send the problem up to do_page_fault
*/
return 1;
break;
}
pgdir = mm->pgd;
if (pgdir == NULL)
return 1;
tmp = cpumask_of_cpu(smp_processor_id());
if (user_region && cpus_equal(mm->cpu_vm_mask, tmp))
local = 1;
/* Is this a huge page ? */
if (unlikely(in_hugepage_area(mm->context, ea)))
ret = hash_huge_page(mm, access, ea, vsid, local);
else {
ptep = find_linux_pte(pgdir, ea);
if (ptep == NULL)
return 1;
ret = __hash_page(ea, access, vsid, ptep, trap, local);
}
return ret;
}
void flush_hash_page(unsigned long va, pte_t pte, int local)
{
unsigned long vpn, hash, secondary, slot;
unsigned long huge = pte_huge(pte);
if (huge)
vpn = va >> HPAGE_SHIFT;
else
vpn = va >> PAGE_SHIFT;
hash = hpt_hash(vpn, huge);
secondary = (pte_val(pte) & _PAGE_SECONDARY) >> 15;
if (secondary)
hash = ~hash;
slot = (hash & htab_hash_mask) * HPTES_PER_GROUP;
slot += (pte_val(pte) & _PAGE_GROUP_IX) >> 12;
ppc_md.hpte_invalidate(slot, va, huge, local);
}
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->vaddr[i], batch->pte[i], local);
}
}
static inline void make_bl(unsigned int *insn_addr, void *func)
{
unsigned long funcp = *((unsigned long *)func);
int offset = funcp - (unsigned long)insn_addr;
*insn_addr = (unsigned int)(0x48000001 | (offset & 0x03fffffc));
flush_icache_range((unsigned long)insn_addr, 4+
(unsigned long)insn_addr);
}
/*
* 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)
{
if (user_mode(regs)) {
siginfo_t info;
info.si_signo = SIGBUS;
info.si_errno = 0;
info.si_code = BUS_ADRERR;
info.si_addr = (void __user *)address;
force_sig_info(SIGBUS, &info, current);
return;
}
bad_page_fault(regs, address, SIGBUS);
}
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;
make_bl(htab_call_hpte_insert1, ppc_md.hpte_insert);
make_bl(htab_call_hpte_insert2, ppc_md.hpte_insert);
make_bl(htab_call_hpte_remove, ppc_md.hpte_remove);
make_bl(htab_call_hpte_updatepp, ppc_md.hpte_updatepp);
}
