linux-stable/arch/powerpc/mm/hash_utils_64.c
Benjamin Herrenschmidt 3c726f8dee [PATCH] ppc64: support 64k pages
Adds a new CONFIG_PPC_64K_PAGES which, when enabled, changes the kernel
base page size to 64K.  The resulting kernel still boots on any
hardware.  On current machines with 4K pages support only, the kernel
will maintain 16 "subpages" for each 64K page transparently.

Note that while real 64K capable HW has been tested, the current patch
will not enable it yet as such hardware is not released yet, and I'm
still verifying with the firmware architects the proper to get the
information from the newer hypervisors.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-06 16:56:47 -08:00

757 lines
19 KiB
C

/*
* 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/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/ppcdebug.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
#ifdef DEBUG_LOW
#define DBG_LOW(fmt...) udbg_printf(fmt)
#else
#define DBG_LOW(fmt...)
#endif
#define KB (1024)
#define MB (1024*KB)
/*
* 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;
struct mmu_psize_def mmu_psize_defs[MMU_PAGE_COUNT];
int mmu_linear_psize = MMU_PAGE_4K;
int mmu_virtual_psize = MMU_PAGE_4K;
#ifdef CONFIG_HUGETLB_PAGE
int mmu_huge_psize = MMU_PAGE_16M;
unsigned int HPAGE_SHIFT;
#endif
/* There are definitions of page sizes arrays to be used when none
* is provided by the firmware.
*/
/* Pre-POWER4 CPUs (4k pages only)
*/
struct mmu_psize_def mmu_psize_defaults_old[] = {
[MMU_PAGE_4K] = {
.shift = 12,
.sllp = 0,
.penc = 0,
.avpnm = 0,
.tlbiel = 0,
},
};
/* POWER4, GPUL, POWER5
*
* Support for 16Mb large pages
*/
struct mmu_psize_def mmu_psize_defaults_gp[] = {
[MMU_PAGE_4K] = {
.shift = 12,
.sllp = 0,
.penc = 0,
.avpnm = 0,
.tlbiel = 1,
},
[MMU_PAGE_16M] = {
.shift = 24,
.sllp = SLB_VSID_L,
.penc = 0,
.avpnm = 0x1UL,
.tlbiel = 0,
},
};
int htab_bolt_mapping(unsigned long vstart, unsigned long vend,
unsigned long pstart, unsigned long mode, int psize)
{
unsigned long vaddr, paddr;
unsigned int step, shift;
unsigned long tmp_mode;
int ret = 0;
shift = mmu_psize_defs[psize].shift;
step = 1 << shift;
for (vaddr = vstart, paddr = pstart; vaddr < vend;
vaddr += step, paddr += step) {
unsigned long vpn, hash, hpteg;
unsigned long vsid = get_kernel_vsid(vaddr);
unsigned long va = (vsid << 28) | (vaddr & 0x0fffffff);
vpn = va >> shift;
tmp_mode = mode;
/* Make non-kernel text non-executable */
if (!in_kernel_text(vaddr))
tmp_mode = mode | HPTE_R_N;
hash = hpt_hash(va, shift);
hpteg = ((hash & htab_hash_mask) * HPTES_PER_GROUP);
/* The crap below can be cleaned once ppd_md.probe() can
* set up the hash callbacks, thus we can just used the
* normal insert callback here.
*/
#ifdef CONFIG_PPC_ISERIES
if (systemcfg->platform == PLATFORM_ISERIES_LPAR)
ret = iSeries_hpte_insert(hpteg, va,
virt_to_abs(paddr),
tmp_mode,
HPTE_V_BOLTED,
psize);
else
#endif
#ifdef CONFIG_PPC_PSERIES
if (systemcfg->platform & PLATFORM_LPAR)
ret = pSeries_lpar_hpte_insert(hpteg, va,
virt_to_abs(paddr),
tmp_mode,
HPTE_V_BOLTED,
psize);
else
#endif
#ifdef CONFIG_PPC_MULTIPLATFORM
ret = native_hpte_insert(hpteg, va,
virt_to_abs(paddr),
tmp_mode, HPTE_V_BOLTED,
psize);
#endif
if (ret < 0)
break;
}
return ret < 0 ? ret : 0;
}
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) {
DBG("Page sizes from device-tree:\n");
size /= 4;
cur_cpu_spec->cpu_features &= ~(CPU_FTR_16M_PAGE);
while(size > 0) {
unsigned int shift = prop[0];
unsigned int slbenc = prop[1];
unsigned int lpnum = prop[2];
unsigned int lpenc = 0;
struct mmu_psize_def *def;
int idx = -1;
size -= 3; prop += 3;
while(size > 0 && lpnum) {
if (prop[0] == shift)
lpenc = prop[1];
prop += 2; size -= 2;
lpnum--;
}
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;
cur_cpu_spec->cpu_features |= CPU_FTR_16M_PAGE;
break;
case 0x22:
idx = MMU_PAGE_16G;
break;
}
if (idx < 0)
continue;
def = &mmu_psize_defs[idx];
def->shift = shift;
if (shift <= 23)
def->avpnm = 0;
else
def->avpnm = (1 << (shift - 23)) - 1;
def->sllp = slbenc;
def->penc = lpenc;
/* We don't know for sure what's up with tlbiel, so
* for now we only set it for 4K and 64K pages
*/
if (idx == MMU_PAGE_4K || idx == MMU_PAGE_64K)
def->tlbiel = 1;
else
def->tlbiel = 0;
DBG(" %d: shift=%02x, sllp=%04x, avpnm=%08x, "
"tlbiel=%d, penc=%d\n",
idx, shift, def->sllp, def->avpnm, def->tlbiel,
def->penc);
}
return 1;
}
return 0;
}
static void __init htab_init_page_sizes(void)
{
int rc;
/* 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 ((systemcfg->platform != PLATFORM_ISERIES_LPAR) &&
cpu_has_feature(CPU_FTR_16M_PAGE))
memcpy(mmu_psize_defs, mmu_psize_defaults_gp,
sizeof(mmu_psize_defaults_gp));
found:
/*
* 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;
/*
* Pick a size for the ordinary pages. Default is 4K, we support
* 64K if cache inhibited large pages are supported by the
* processor
*/
#ifdef CONFIG_PPC_64K_PAGES
if (mmu_psize_defs[MMU_PAGE_64K].shift &&
cpu_has_feature(CPU_FTR_CI_LARGE_PAGE))
mmu_virtual_psize = MMU_PAGE_64K;
#endif
printk(KERN_INFO "Page orders: linear mapping = %d, others = %d\n",
mmu_psize_defs[mmu_linear_psize].shift,
mmu_psize_defs[mmu_virtual_psize].shift);
#ifdef CONFIG_HUGETLB_PAGE
/* Init large page size. Currently, we pick 16M or 1M depending
* on what is available
*/
if (mmu_psize_defs[MMU_PAGE_16M].shift)
mmu_huge_psize = MMU_PAGE_16M;
else if (mmu_psize_defs[MMU_PAGE_1M].shift)
mmu_huge_psize = MMU_PAGE_1M;
/* Calculate HPAGE_SHIFT and sanity check it */
if (mmu_psize_defs[mmu_huge_psize].shift > 16 &&
mmu_psize_defs[mmu_huge_psize].shift < 28)
HPAGE_SHIFT = mmu_psize_defs[mmu_huge_psize].shift;
else
HPAGE_SHIFT = 0; /* No huge pages dude ! */
#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 rnd_mem_size, pteg_count;
/* If hash size isn't already provided by the platform, we try to
* retreive 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 */
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;
unsigned long base = 0, size = 0;
int i;
extern unsigned long tce_alloc_start, tce_alloc_end;
DBG(" -> htab_initialize()\n");
/* Initialize page sizes */
htab_init_page_sizes();
/*
* 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;
/* For debug, make the HTAB 1/8 as big as it normally would be. */
ifppcdebug(PPCDBG_HTABSIZE) {
pteg_count >>= 3;
htab_size_bytes = pteg_count << 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);
BUG_ON(table == 0);
DBG("Hash table allocated at %lx, size: %lx\n", table,
htab_size_bytes);
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
*/
/* 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)
BUG_ON(htab_bolt_mapping(base, dart_tablebase,
base, mode_rw,
mmu_linear_psize));
if ((base + size) > (dart_tablebase + 16*MB))
BUG_ON(htab_bolt_mapping(dart_tablebase+16*MB,
base + size,
dart_tablebase+16*MB,
mode_rw,
mmu_linear_psize));
continue;
}
#endif /* CONFIG_U3_DART */
BUG_ON(htab_bolt_mapping(base, base + size, base,
mode_rw, mmu_linear_psize));
}
/*
* 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;
BUG_ON(htab_bolt_mapping(tce_alloc_start, tce_alloc_end,
tce_alloc_start, mode_rw,
mmu_linear_psize));
}
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;
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 |= HPTE_R_N;
}
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;
cpumask_t tmp;
int rc, user_region = 0, local = 0;
DBG_LOW("hash_page(ea=%016lx, access=%lx, trap=%lx\n",
ea, access, trap);
if ((ea & ~REGION_MASK) >= PGTABLE_RANGE) {
DBG_LOW(" out of pgtable range !\n");
return 1;
}
/* 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");
return 1;
}
vsid = get_vsid(mm->context.id, ea);
break;
case VMALLOC_REGION_ID:
mm = &init_mm;
vsid = get_kernel_vsid(ea);
break;
default:
/* Not a valid range
* Send the problem up to do_page_fault
*/
return 1;
}
DBG_LOW(" mm=%p, mm->pgdir=%p, vsid=%016lx\n", mm, mm->pgd, vsid);
/* Get pgdir */
pgdir = mm->pgd;
if (pgdir == NULL)
return 1;
/* Check CPU locality */
tmp = cpumask_of_cpu(smp_processor_id());
if (user_region && cpus_equal(mm->cpu_vm_mask, tmp))
local = 1;
/* Handle hugepage regions */
if (unlikely(in_hugepage_area(mm->context, ea))) {
DBG_LOW(" -> huge page !\n");
return hash_huge_page(mm, access, ea, vsid, local);
}
/* Get PTE and page size from page tables */
ptep = find_linux_pte(pgdir, ea);
if (ptep == NULL || !pte_present(*ptep)) {
DBG_LOW(" no PTE !\n");
return 1;
}
#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
/* 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");
return 1;
}
/* Do actual hashing */
#ifndef CONFIG_PPC_64K_PAGES
rc = __hash_page_4K(ea, access, vsid, ptep, trap, local);
#else
if (mmu_virtual_psize == MMU_PAGE_64K)
rc = __hash_page_64K(ea, access, vsid, ptep, trap, local);
else
rc = __hash_page_4K(ea, access, vsid, ptep, trap, local);
#endif /* CONFIG_PPC_64K_PAGES */
#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);
return rc;
}
void hash_preload(struct mm_struct *mm, unsigned long ea,
unsigned long access, unsigned long trap)
{
unsigned long vsid;
void *pgdir;
pte_t *ptep;
cpumask_t mask;
unsigned long flags;
int local = 0;
/* We don't want huge pages prefaulted for now
*/
if (unlikely(in_hugepage_area(mm->context, ea)))
return;
DBG_LOW("hash_preload(mm=%p, mm->pgdir=%p, ea=%016lx, access=%lx,"
" trap=%lx\n", mm, mm->pgd, ea, access, trap);
/* Get PTE, VSID, access mask */
pgdir = mm->pgd;
if (pgdir == NULL)
return;
ptep = find_linux_pte(pgdir, ea);
if (!ptep)
return;
vsid = get_vsid(mm->context.id, ea);
/* Hash it in */
local_irq_save(flags);
mask = cpumask_of_cpu(smp_processor_id());
if (cpus_equal(mm->cpu_vm_mask, mask))
local = 1;
#ifndef CONFIG_PPC_64K_PAGES
__hash_page_4K(ea, access, vsid, ptep, trap, local);
#else
if (mmu_virtual_psize == MMU_PAGE_64K)
__hash_page_64K(ea, access, vsid, ptep, trap, local);
else
__hash_page_4K(ea, access, vsid, ptep, trap, local);
#endif /* CONFIG_PPC_64K_PAGES */
local_irq_restore(flags);
}
void flush_hash_page(unsigned long va, real_pte_t pte, int psize, int local)
{
unsigned long hash, index, shift, hidx, slot;
DBG_LOW("flush_hash_page(va=%016x)\n", va);
pte_iterate_hashed_subpages(pte, psize, va, index, shift) {
hash = hpt_hash(va, shift);
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 %d: hash=%x, hidx=%x\n", index, slot, hidx);
ppc_md.hpte_invalidate(slot, va, psize, local);
} pte_iterate_hashed_end();
}
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],
batch->psize, 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;
#ifdef CONFIG_PPC_64K_PAGES
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;
make_bl(ht64_call_hpte_insert1, ppc_md.hpte_insert);
make_bl(ht64_call_hpte_insert2, ppc_md.hpte_insert);
make_bl(ht64_call_hpte_remove, ppc_md.hpte_remove);
make_bl(ht64_call_hpte_updatepp, ppc_md.hpte_updatepp);
#endif /* CONFIG_PPC_64K_PAGES */
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);
}