linux/arch/powerpc/mm/tlb_nohash.c
Scott Wood 609af38f8f powerpc/booke64: Critical and machine check exception support
Add special state saving for critical and machine check exceptions.

Most of this code could be used to handle debug exceptions taken from
kernel space, but actually doing so is outside the scope of this patch.

The various critical and machine check exceptions now point to their
real handlers, rather than hanging the kernel.

Signed-off-by: Scott Wood <scottwood@freescale.com>
2014-03-19 19:57:27 -05:00

728 lines
18 KiB
C

/*
* This file contains the routines for TLB flushing.
* On machines where the MMU does not use a hash table to store virtual to
* physical translations (ie, SW loaded TLBs or Book3E compilant processors,
* this does -not- include 603 however which shares the implementation with
* hash based processors)
*
* -- BenH
*
* Copyright 2008,2009 Ben Herrenschmidt <benh@kernel.crashing.org>
* IBM Corp.
*
* Derived from arch/ppc/mm/init.c:
* Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
*
* Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
* and Cort Dougan (PReP) (cort@cs.nmt.edu)
* Copyright (C) 1996 Paul Mackerras
*
* Derived from "arch/i386/mm/init.c"
* Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
*
* 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.
*
*/
#include <linux/kernel.h>
#include <linux/export.h>
#include <linux/mm.h>
#include <linux/init.h>
#include <linux/highmem.h>
#include <linux/pagemap.h>
#include <linux/preempt.h>
#include <linux/spinlock.h>
#include <linux/memblock.h>
#include <linux/of_fdt.h>
#include <linux/hugetlb.h>
#include <asm/tlbflush.h>
#include <asm/tlb.h>
#include <asm/code-patching.h>
#include <asm/hugetlb.h>
#include <asm/paca.h>
#include "mmu_decl.h"
/*
* This struct lists the sw-supported page sizes. The hardawre MMU may support
* other sizes not listed here. The .ind field is only used on MMUs that have
* indirect page table entries.
*/
#ifdef CONFIG_PPC_BOOK3E_MMU
#ifdef CONFIG_PPC_FSL_BOOK3E
struct mmu_psize_def mmu_psize_defs[MMU_PAGE_COUNT] = {
[MMU_PAGE_4K] = {
.shift = 12,
.enc = BOOK3E_PAGESZ_4K,
},
[MMU_PAGE_2M] = {
.shift = 21,
.enc = BOOK3E_PAGESZ_2M,
},
[MMU_PAGE_4M] = {
.shift = 22,
.enc = BOOK3E_PAGESZ_4M,
},
[MMU_PAGE_16M] = {
.shift = 24,
.enc = BOOK3E_PAGESZ_16M,
},
[MMU_PAGE_64M] = {
.shift = 26,
.enc = BOOK3E_PAGESZ_64M,
},
[MMU_PAGE_256M] = {
.shift = 28,
.enc = BOOK3E_PAGESZ_256M,
},
[MMU_PAGE_1G] = {
.shift = 30,
.enc = BOOK3E_PAGESZ_1GB,
},
};
#else
struct mmu_psize_def mmu_psize_defs[MMU_PAGE_COUNT] = {
[MMU_PAGE_4K] = {
.shift = 12,
.ind = 20,
.enc = BOOK3E_PAGESZ_4K,
},
[MMU_PAGE_16K] = {
.shift = 14,
.enc = BOOK3E_PAGESZ_16K,
},
[MMU_PAGE_64K] = {
.shift = 16,
.ind = 28,
.enc = BOOK3E_PAGESZ_64K,
},
[MMU_PAGE_1M] = {
.shift = 20,
.enc = BOOK3E_PAGESZ_1M,
},
[MMU_PAGE_16M] = {
.shift = 24,
.ind = 36,
.enc = BOOK3E_PAGESZ_16M,
},
[MMU_PAGE_256M] = {
.shift = 28,
.enc = BOOK3E_PAGESZ_256M,
},
[MMU_PAGE_1G] = {
.shift = 30,
.enc = BOOK3E_PAGESZ_1GB,
},
};
#endif /* CONFIG_FSL_BOOKE */
static inline int mmu_get_tsize(int psize)
{
return mmu_psize_defs[psize].enc;
}
#else
static inline int mmu_get_tsize(int psize)
{
/* This isn't used on !Book3E for now */
return 0;
}
#endif /* CONFIG_PPC_BOOK3E_MMU */
/* The variables below are currently only used on 64-bit Book3E
* though this will probably be made common with other nohash
* implementations at some point
*/
#ifdef CONFIG_PPC64
int mmu_linear_psize; /* Page size used for the linear mapping */
int mmu_pte_psize; /* Page size used for PTE pages */
int mmu_vmemmap_psize; /* Page size used for the virtual mem map */
int book3e_htw_mode; /* HW tablewalk? Value is PPC_HTW_* */
unsigned long linear_map_top; /* Top of linear mapping */
/*
* Number of bytes to add to SPRN_SPRG_TLB_EXFRAME on crit/mcheck/debug
* exceptions. This is used for bolted and e6500 TLB miss handlers which
* do not modify this SPRG in the TLB miss code; for other TLB miss handlers,
* this is set to zero.
*/
int extlb_level_exc;
#endif /* CONFIG_PPC64 */
#ifdef CONFIG_PPC_FSL_BOOK3E
/* next_tlbcam_idx is used to round-robin tlbcam entry assignment */
DEFINE_PER_CPU(int, next_tlbcam_idx);
EXPORT_PER_CPU_SYMBOL(next_tlbcam_idx);
#endif
/*
* Base TLB flushing operations:
*
* - flush_tlb_mm(mm) flushes the specified mm context TLB's
* - flush_tlb_page(vma, vmaddr) flushes one page
* - flush_tlb_range(vma, start, end) flushes a range of pages
* - flush_tlb_kernel_range(start, end) flushes kernel pages
*
* - local_* variants of page and mm only apply to the current
* processor
*/
/*
* These are the base non-SMP variants of page and mm flushing
*/
void local_flush_tlb_mm(struct mm_struct *mm)
{
unsigned int pid;
preempt_disable();
pid = mm->context.id;
if (pid != MMU_NO_CONTEXT)
_tlbil_pid(pid);
preempt_enable();
}
EXPORT_SYMBOL(local_flush_tlb_mm);
void __local_flush_tlb_page(struct mm_struct *mm, unsigned long vmaddr,
int tsize, int ind)
{
unsigned int pid;
preempt_disable();
pid = mm ? mm->context.id : 0;
if (pid != MMU_NO_CONTEXT)
_tlbil_va(vmaddr, pid, tsize, ind);
preempt_enable();
}
void local_flush_tlb_page(struct vm_area_struct *vma, unsigned long vmaddr)
{
__local_flush_tlb_page(vma ? vma->vm_mm : NULL, vmaddr,
mmu_get_tsize(mmu_virtual_psize), 0);
}
EXPORT_SYMBOL(local_flush_tlb_page);
/*
* And here are the SMP non-local implementations
*/
#ifdef CONFIG_SMP
static DEFINE_RAW_SPINLOCK(tlbivax_lock);
static int mm_is_core_local(struct mm_struct *mm)
{
return cpumask_subset(mm_cpumask(mm),
topology_thread_cpumask(smp_processor_id()));
}
struct tlb_flush_param {
unsigned long addr;
unsigned int pid;
unsigned int tsize;
unsigned int ind;
};
static void do_flush_tlb_mm_ipi(void *param)
{
struct tlb_flush_param *p = param;
_tlbil_pid(p ? p->pid : 0);
}
static void do_flush_tlb_page_ipi(void *param)
{
struct tlb_flush_param *p = param;
_tlbil_va(p->addr, p->pid, p->tsize, p->ind);
}
/* Note on invalidations and PID:
*
* We snapshot the PID with preempt disabled. At this point, it can still
* change either because:
* - our context is being stolen (PID -> NO_CONTEXT) on another CPU
* - we are invaliating some target that isn't currently running here
* and is concurrently acquiring a new PID on another CPU
* - some other CPU is re-acquiring a lost PID for this mm
* etc...
*
* However, this shouldn't be a problem as we only guarantee
* invalidation of TLB entries present prior to this call, so we
* don't care about the PID changing, and invalidating a stale PID
* is generally harmless.
*/
void flush_tlb_mm(struct mm_struct *mm)
{
unsigned int pid;
preempt_disable();
pid = mm->context.id;
if (unlikely(pid == MMU_NO_CONTEXT))
goto no_context;
if (!mm_is_core_local(mm)) {
struct tlb_flush_param p = { .pid = pid };
/* Ignores smp_processor_id() even if set. */
smp_call_function_many(mm_cpumask(mm),
do_flush_tlb_mm_ipi, &p, 1);
}
_tlbil_pid(pid);
no_context:
preempt_enable();
}
EXPORT_SYMBOL(flush_tlb_mm);
void __flush_tlb_page(struct mm_struct *mm, unsigned long vmaddr,
int tsize, int ind)
{
struct cpumask *cpu_mask;
unsigned int pid;
preempt_disable();
pid = mm ? mm->context.id : 0;
if (unlikely(pid == MMU_NO_CONTEXT))
goto bail;
cpu_mask = mm_cpumask(mm);
if (!mm_is_core_local(mm)) {
/* If broadcast tlbivax is supported, use it */
if (mmu_has_feature(MMU_FTR_USE_TLBIVAX_BCAST)) {
int lock = mmu_has_feature(MMU_FTR_LOCK_BCAST_INVAL);
if (lock)
raw_spin_lock(&tlbivax_lock);
_tlbivax_bcast(vmaddr, pid, tsize, ind);
if (lock)
raw_spin_unlock(&tlbivax_lock);
goto bail;
} else {
struct tlb_flush_param p = {
.pid = pid,
.addr = vmaddr,
.tsize = tsize,
.ind = ind,
};
/* Ignores smp_processor_id() even if set in cpu_mask */
smp_call_function_many(cpu_mask,
do_flush_tlb_page_ipi, &p, 1);
}
}
_tlbil_va(vmaddr, pid, tsize, ind);
bail:
preempt_enable();
}
void flush_tlb_page(struct vm_area_struct *vma, unsigned long vmaddr)
{
#ifdef CONFIG_HUGETLB_PAGE
if (vma && is_vm_hugetlb_page(vma))
flush_hugetlb_page(vma, vmaddr);
#endif
__flush_tlb_page(vma ? vma->vm_mm : NULL, vmaddr,
mmu_get_tsize(mmu_virtual_psize), 0);
}
EXPORT_SYMBOL(flush_tlb_page);
#endif /* CONFIG_SMP */
#ifdef CONFIG_PPC_47x
void __init early_init_mmu_47x(void)
{
#ifdef CONFIG_SMP
unsigned long root = of_get_flat_dt_root();
if (of_get_flat_dt_prop(root, "cooperative-partition", NULL))
mmu_clear_feature(MMU_FTR_USE_TLBIVAX_BCAST);
#endif /* CONFIG_SMP */
}
#endif /* CONFIG_PPC_47x */
/*
* Flush kernel TLB entries in the given range
*/
void flush_tlb_kernel_range(unsigned long start, unsigned long end)
{
#ifdef CONFIG_SMP
preempt_disable();
smp_call_function(do_flush_tlb_mm_ipi, NULL, 1);
_tlbil_pid(0);
preempt_enable();
#else
_tlbil_pid(0);
#endif
}
EXPORT_SYMBOL(flush_tlb_kernel_range);
/*
* Currently, for range flushing, we just do a full mm flush. This should
* be optimized based on a threshold on the size of the range, since
* some implementation can stack multiple tlbivax before a tlbsync but
* for now, we keep it that way
*/
void flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
unsigned long end)
{
flush_tlb_mm(vma->vm_mm);
}
EXPORT_SYMBOL(flush_tlb_range);
void tlb_flush(struct mmu_gather *tlb)
{
flush_tlb_mm(tlb->mm);
}
/*
* Below are functions specific to the 64-bit variant of Book3E though that
* may change in the future
*/
#ifdef CONFIG_PPC64
/*
* Handling of virtual linear page tables or indirect TLB entries
* flushing when PTE pages are freed
*/
void tlb_flush_pgtable(struct mmu_gather *tlb, unsigned long address)
{
int tsize = mmu_psize_defs[mmu_pte_psize].enc;
if (book3e_htw_mode != PPC_HTW_NONE) {
unsigned long start = address & PMD_MASK;
unsigned long end = address + PMD_SIZE;
unsigned long size = 1UL << mmu_psize_defs[mmu_pte_psize].shift;
/* This isn't the most optimal, ideally we would factor out the
* while preempt & CPU mask mucking around, or even the IPI but
* it will do for now
*/
while (start < end) {
__flush_tlb_page(tlb->mm, start, tsize, 1);
start += size;
}
} else {
unsigned long rmask = 0xf000000000000000ul;
unsigned long rid = (address & rmask) | 0x1000000000000000ul;
unsigned long vpte = address & ~rmask;
#ifdef CONFIG_PPC_64K_PAGES
vpte = (vpte >> (PAGE_SHIFT - 4)) & ~0xfffful;
#else
vpte = (vpte >> (PAGE_SHIFT - 3)) & ~0xffful;
#endif
vpte |= rid;
__flush_tlb_page(tlb->mm, vpte, tsize, 0);
}
}
static void setup_page_sizes(void)
{
unsigned int tlb0cfg;
unsigned int tlb0ps;
unsigned int eptcfg;
int i, psize;
#ifdef CONFIG_PPC_FSL_BOOK3E
unsigned int mmucfg = mfspr(SPRN_MMUCFG);
int fsl_mmu = mmu_has_feature(MMU_FTR_TYPE_FSL_E);
if (fsl_mmu && (mmucfg & MMUCFG_MAVN) == MMUCFG_MAVN_V1) {
unsigned int tlb1cfg = mfspr(SPRN_TLB1CFG);
unsigned int min_pg, max_pg;
min_pg = (tlb1cfg & TLBnCFG_MINSIZE) >> TLBnCFG_MINSIZE_SHIFT;
max_pg = (tlb1cfg & TLBnCFG_MAXSIZE) >> TLBnCFG_MAXSIZE_SHIFT;
for (psize = 0; psize < MMU_PAGE_COUNT; ++psize) {
struct mmu_psize_def *def;
unsigned int shift;
def = &mmu_psize_defs[psize];
shift = def->shift;
if (shift == 0 || shift & 1)
continue;
/* adjust to be in terms of 4^shift Kb */
shift = (shift - 10) >> 1;
if ((shift >= min_pg) && (shift <= max_pg))
def->flags |= MMU_PAGE_SIZE_DIRECT;
}
goto out;
}
if (fsl_mmu && (mmucfg & MMUCFG_MAVN) == MMUCFG_MAVN_V2) {
u32 tlb1cfg, tlb1ps;
tlb0cfg = mfspr(SPRN_TLB0CFG);
tlb1cfg = mfspr(SPRN_TLB1CFG);
tlb1ps = mfspr(SPRN_TLB1PS);
eptcfg = mfspr(SPRN_EPTCFG);
if ((tlb1cfg & TLBnCFG_IND) && (tlb0cfg & TLBnCFG_PT))
book3e_htw_mode = PPC_HTW_E6500;
/*
* We expect 4K subpage size and unrestricted indirect size.
* The lack of a restriction on indirect size is a Freescale
* extension, indicated by PSn = 0 but SPSn != 0.
*/
if (eptcfg != 2)
book3e_htw_mode = PPC_HTW_NONE;
for (psize = 0; psize < MMU_PAGE_COUNT; ++psize) {
struct mmu_psize_def *def = &mmu_psize_defs[psize];
if (tlb1ps & (1U << (def->shift - 10))) {
def->flags |= MMU_PAGE_SIZE_DIRECT;
if (book3e_htw_mode && psize == MMU_PAGE_2M)
def->flags |= MMU_PAGE_SIZE_INDIRECT;
}
}
goto out;
}
#endif
tlb0cfg = mfspr(SPRN_TLB0CFG);
tlb0ps = mfspr(SPRN_TLB0PS);
eptcfg = mfspr(SPRN_EPTCFG);
/* Look for supported direct sizes */
for (psize = 0; psize < MMU_PAGE_COUNT; ++psize) {
struct mmu_psize_def *def = &mmu_psize_defs[psize];
if (tlb0ps & (1U << (def->shift - 10)))
def->flags |= MMU_PAGE_SIZE_DIRECT;
}
/* Indirect page sizes supported ? */
if ((tlb0cfg & TLBnCFG_IND) == 0 ||
(tlb0cfg & TLBnCFG_PT) == 0)
goto out;
book3e_htw_mode = PPC_HTW_IBM;
/* Now, we only deal with one IND page size for each
* direct size. Hopefully all implementations today are
* unambiguous, but we might want to be careful in the
* future.
*/
for (i = 0; i < 3; i++) {
unsigned int ps, sps;
sps = eptcfg & 0x1f;
eptcfg >>= 5;
ps = eptcfg & 0x1f;
eptcfg >>= 5;
if (!ps || !sps)
continue;
for (psize = 0; psize < MMU_PAGE_COUNT; psize++) {
struct mmu_psize_def *def = &mmu_psize_defs[psize];
if (ps == (def->shift - 10))
def->flags |= MMU_PAGE_SIZE_INDIRECT;
if (sps == (def->shift - 10))
def->ind = ps + 10;
}
}
out:
/* Cleanup array and print summary */
pr_info("MMU: Supported page sizes\n");
for (psize = 0; psize < MMU_PAGE_COUNT; ++psize) {
struct mmu_psize_def *def = &mmu_psize_defs[psize];
const char *__page_type_names[] = {
"unsupported",
"direct",
"indirect",
"direct & indirect"
};
if (def->flags == 0) {
def->shift = 0;
continue;
}
pr_info(" %8ld KB as %s\n", 1ul << (def->shift - 10),
__page_type_names[def->flags & 0x3]);
}
}
static void setup_mmu_htw(void)
{
/*
* If we want to use HW tablewalk, enable it by patching the TLB miss
* handlers to branch to the one dedicated to it.
*/
switch (book3e_htw_mode) {
case PPC_HTW_IBM:
patch_exception(0x1c0, exc_data_tlb_miss_htw_book3e);
patch_exception(0x1e0, exc_instruction_tlb_miss_htw_book3e);
break;
#ifdef CONFIG_PPC_FSL_BOOK3E
case PPC_HTW_E6500:
extlb_level_exc = EX_TLB_SIZE;
patch_exception(0x1c0, exc_data_tlb_miss_e6500_book3e);
patch_exception(0x1e0, exc_instruction_tlb_miss_e6500_book3e);
break;
#endif
}
pr_info("MMU: Book3E HW tablewalk %s\n",
book3e_htw_mode != PPC_HTW_NONE ? "enabled" : "not supported");
}
/*
* Early initialization of the MMU TLB code
*/
static void __early_init_mmu(int boot_cpu)
{
unsigned int mas4;
/* XXX This will have to be decided at runtime, but right
* now our boot and TLB miss code hard wires it. Ideally
* we should find out a suitable page size and patch the
* TLB miss code (either that or use the PACA to store
* the value we want)
*/
mmu_linear_psize = MMU_PAGE_1G;
/* XXX This should be decided at runtime based on supported
* page sizes in the TLB, but for now let's assume 16M is
* always there and a good fit (which it probably is)
*/
mmu_vmemmap_psize = MMU_PAGE_16M;
/* XXX This code only checks for TLB 0 capabilities and doesn't
* check what page size combos are supported by the HW. It
* also doesn't handle the case where a separate array holds
* the IND entries from the array loaded by the PT.
*/
if (boot_cpu) {
/* Look for supported page sizes */
setup_page_sizes();
/* Look for HW tablewalk support */
setup_mmu_htw();
}
/* Set MAS4 based on page table setting */
mas4 = 0x4 << MAS4_WIMGED_SHIFT;
switch (book3e_htw_mode) {
case PPC_HTW_E6500:
mas4 |= MAS4_INDD;
mas4 |= BOOK3E_PAGESZ_2M << MAS4_TSIZED_SHIFT;
mas4 |= MAS4_TLBSELD(1);
mmu_pte_psize = MMU_PAGE_2M;
break;
case PPC_HTW_IBM:
mas4 |= MAS4_INDD;
#ifdef CONFIG_PPC_64K_PAGES
mas4 |= BOOK3E_PAGESZ_256M << MAS4_TSIZED_SHIFT;
mmu_pte_psize = MMU_PAGE_256M;
#else
mas4 |= BOOK3E_PAGESZ_1M << MAS4_TSIZED_SHIFT;
mmu_pte_psize = MMU_PAGE_1M;
#endif
break;
case PPC_HTW_NONE:
#ifdef CONFIG_PPC_64K_PAGES
mas4 |= BOOK3E_PAGESZ_64K << MAS4_TSIZED_SHIFT;
#else
mas4 |= BOOK3E_PAGESZ_4K << MAS4_TSIZED_SHIFT;
#endif
mmu_pte_psize = mmu_virtual_psize;
break;
}
mtspr(SPRN_MAS4, mas4);
/* Set the global containing the top of the linear mapping
* for use by the TLB miss code
*/
linear_map_top = memblock_end_of_DRAM();
#ifdef CONFIG_PPC_FSL_BOOK3E
if (mmu_has_feature(MMU_FTR_TYPE_FSL_E)) {
unsigned int num_cams;
/* use a quarter of the TLBCAM for bolted linear map */
num_cams = (mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY) / 4;
linear_map_top = map_mem_in_cams(linear_map_top, num_cams);
/* limit memory so we dont have linear faults */
memblock_enforce_memory_limit(linear_map_top);
if (book3e_htw_mode == PPC_HTW_NONE) {
extlb_level_exc = EX_TLB_SIZE;
patch_exception(0x1c0, exc_data_tlb_miss_bolted_book3e);
patch_exception(0x1e0,
exc_instruction_tlb_miss_bolted_book3e);
}
}
#endif
/* A sync won't hurt us after mucking around with
* the MMU configuration
*/
mb();
memblock_set_current_limit(linear_map_top);
}
void __init early_init_mmu(void)
{
__early_init_mmu(1);
}
void early_init_mmu_secondary(void)
{
__early_init_mmu(0);
}
void setup_initial_memory_limit(phys_addr_t first_memblock_base,
phys_addr_t first_memblock_size)
{
/* On non-FSL Embedded 64-bit, we adjust the RMA size to match
* the bolted TLB entry. We know for now that only 1G
* entries are supported though that may eventually
* change.
*
* on FSL Embedded 64-bit, we adjust the RMA size to match the
* first bolted TLB entry size. We still limit max to 1G even if
* the TLB could cover more. This is due to what the early init
* code is setup to do.
*
* We crop it to the size of the first MEMBLOCK to
* avoid going over total available memory just in case...
*/
#ifdef CONFIG_PPC_FSL_BOOK3E
if (mmu_has_feature(MMU_FTR_TYPE_FSL_E)) {
unsigned long linear_sz;
linear_sz = calc_cam_sz(first_memblock_size, PAGE_OFFSET,
first_memblock_base);
ppc64_rma_size = min_t(u64, linear_sz, 0x40000000);
} else
#endif
ppc64_rma_size = min_t(u64, first_memblock_size, 0x40000000);
/* Finally limit subsequent allocations */
memblock_set_current_limit(first_memblock_base + ppc64_rma_size);
}
#else /* ! CONFIG_PPC64 */
void __init early_init_mmu(void)
{
#ifdef CONFIG_PPC_47x
early_init_mmu_47x();
#endif
}
#endif /* CONFIG_PPC64 */