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b4f501916c
linux_dsm_epyc7002/arch/tile/mm/init.c
Christoph Lameter b4f501916c tile: Replace __get_cpu_var uses 
__get_cpu_var() is used for multiple purposes in the kernel source. One of
them is address calculation via the form &__get_cpu_var(x).  This calculates
the address for the instance of the percpu variable of the current processor
based on an offset.

Other use cases are for storing and retrieving data from the current
processors percpu area.  __get_cpu_var() can be used as an lvalue when
writing data or on the right side of an assignment.

__get_cpu_var() is defined as :

#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))

__get_cpu_var() always only does an address determination. However, store
and retrieve operations could use a segment prefix (or global register on
other platforms) to avoid the address calculation.

this_cpu_write() and this_cpu_read() can directly take an offset into a
percpu area and use optimized assembly code to read and write per cpu
variables.

This patch converts __get_cpu_var into either an explicit address
calculation using this_cpu_ptr() or into a use of this_cpu operations that
use the offset.  Thereby address calculations are avoided and less registers
are used when code is generated.

At the end of the patch set all uses of __get_cpu_var have been removed so
the macro is removed too.

The patch set includes passes over all arches as well. Once these operations
are used throughout then specialized macros can be defined in non -x86
arches as well in order to optimize per cpu access by f.e.  using a global
register that may be set to the per cpu base.

Transformations done to __get_cpu_var()

1. Determine the address of the percpu instance of the current processor.

	DEFINE_PER_CPU(int, y);
	int *x = &__get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(&y);

2. Same as #1 but this time an array structure is involved.

	DEFINE_PER_CPU(int, y[20]);
	int *x = __get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(y);

3. Retrieve the content of the current processors instance of a per cpu
variable.

	DEFINE_PER_CPU(int, y);
	int x = __get_cpu_var(y)

   Converts to

	int x = __this_cpu_read(y);

4. Retrieve the content of a percpu struct

	DEFINE_PER_CPU(struct mystruct, y);
	struct mystruct x = __get_cpu_var(y);

   Converts to

	memcpy(&x, this_cpu_ptr(&y), sizeof(x));

5. Assignment to a per cpu variable

	DEFINE_PER_CPU(int, y)
	__get_cpu_var(y) = x;

   Converts to

	__this_cpu_write(y, x);

6. Increment/Decrement etc of a per cpu variable

	DEFINE_PER_CPU(int, y);
	__get_cpu_var(y)++

   Converts to

	__this_cpu_inc(y)

Acked-by: Chris Metcalf <cmetcalf@tilera.com>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2014-08-26 13:45:54 -04:00

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/*
* Copyright (C) 1995 Linus Torvalds
* Copyright 2010 Tilera Corporation. All Rights Reserved.
*
* 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, version 2.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
* NON INFRINGEMENT. See the GNU General Public License for
* more details.
*/
#include <linux/module.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/ptrace.h>
#include <linux/mman.h>
#include <linux/mm.h>
#include <linux/hugetlb.h>
#include <linux/swap.h>
#include <linux/smp.h>
#include <linux/init.h>
#include <linux/highmem.h>
#include <linux/pagemap.h>
#include <linux/poison.h>
#include <linux/bootmem.h>
#include <linux/slab.h>
#include <linux/proc_fs.h>
#include <linux/efi.h>
#include <linux/memory_hotplug.h>
#include <linux/uaccess.h>
#include <asm/mmu_context.h>
#include <asm/processor.h>
#include <asm/pgtable.h>
#include <asm/pgalloc.h>
#include <asm/dma.h>
#include <asm/fixmap.h>
#include <asm/tlb.h>
#include <asm/tlbflush.h>
#include <asm/sections.h>
#include <asm/setup.h>
#include <asm/homecache.h>
#include <hv/hypervisor.h>
#include <arch/chip.h>
#include "migrate.h"
#define clear_pgd(pmdptr) (*(pmdptr) = hv_pte(0))
#ifndef __tilegx__
unsigned long VMALLOC_RESERVE = CONFIG_VMALLOC_RESERVE;
EXPORT_SYMBOL(VMALLOC_RESERVE);
#endif
/* Create an L2 page table */
static pte_t * __init alloc_pte(void)
{
return __alloc_bootmem(L2_KERNEL_PGTABLE_SIZE, HV_PAGE_TABLE_ALIGN, 0);
}
/*
* L2 page tables per controller. We allocate these all at once from
* the bootmem allocator and store them here. This saves on kernel L2
* page table memory, compared to allocating a full 64K page per L2
* page table, and also means that in cases where we use huge pages,
* we are guaranteed to later be able to shatter those huge pages and
* switch to using these page tables instead, without requiring
* further allocation. Each l2_ptes[] entry points to the first page
* table for the first hugepage-size piece of memory on the
* controller; other page tables are just indexed directly, i.e. the
* L2 page tables are contiguous in memory for each controller.
*/
static pte_t *l2_ptes[MAX_NUMNODES];
static int num_l2_ptes[MAX_NUMNODES];
static void init_prealloc_ptes(int node, int pages)
{
BUG_ON(pages & (PTRS_PER_PTE - 1));
if (pages) {
num_l2_ptes[node] = pages;
l2_ptes[node] = __alloc_bootmem(pages * sizeof(pte_t),
HV_PAGE_TABLE_ALIGN, 0);
}
}
pte_t *get_prealloc_pte(unsigned long pfn)
{
int node = pfn_to_nid(pfn);
pfn &= ~(-1UL << (NR_PA_HIGHBIT_SHIFT - PAGE_SHIFT));
BUG_ON(node >= MAX_NUMNODES);
BUG_ON(pfn >= num_l2_ptes[node]);
return &l2_ptes[node][pfn];
}
/*
* What caching do we expect pages from the heap to have when
* they are allocated during bootup? (Once we've installed the
* "real" swapper_pg_dir.)
*/
static int initial_heap_home(void)
{
if (hash_default)
return PAGE_HOME_HASH;
return smp_processor_id();
}
/*
* Place a pointer to an L2 page table in a middle page
* directory entry.
*/
static void __init assign_pte(pmd_t *pmd, pte_t *page_table)
{
phys_addr_t pa = __pa(page_table);
unsigned long l2_ptfn = pa >> HV_LOG2_PAGE_TABLE_ALIGN;
pte_t pteval = hv_pte_set_ptfn(__pgprot(_PAGE_TABLE), l2_ptfn);
BUG_ON((pa & (HV_PAGE_TABLE_ALIGN-1)) != 0);
pteval = pte_set_home(pteval, initial_heap_home());
*(pte_t *)pmd = pteval;
if (page_table != (pte_t *)pmd_page_vaddr(*pmd))
BUG();
}
#ifdef __tilegx__
static inline pmd_t *alloc_pmd(void)
{
return __alloc_bootmem(L1_KERNEL_PGTABLE_SIZE, HV_PAGE_TABLE_ALIGN, 0);
}
static inline void assign_pmd(pud_t *pud, pmd_t *pmd)
{
assign_pte((pmd_t *)pud, (pte_t *)pmd);
}
#endif /* __tilegx__ */
/* Replace the given pmd with a full PTE table. */
void __init shatter_pmd(pmd_t *pmd)
{
pte_t *pte = get_prealloc_pte(pte_pfn(*(pte_t *)pmd));
assign_pte(pmd, pte);
}
#ifdef __tilegx__
static pmd_t *__init get_pmd(pgd_t pgtables[], unsigned long va)
{
pud_t *pud = pud_offset(&pgtables[pgd_index(va)], va);
if (pud_none(*pud))
assign_pmd(pud, alloc_pmd());
return pmd_offset(pud, va);
}
#else
static pmd_t *__init get_pmd(pgd_t pgtables[], unsigned long va)
{
return pmd_offset(pud_offset(&pgtables[pgd_index(va)], va), va);
}
#endif
/*
* This function initializes a certain range of kernel virtual memory
* with new bootmem page tables, everywhere page tables are missing in
* the given range.
*/
/*
* NOTE: The pagetables are allocated contiguous on the physical space
* so we can cache the place of the first one and move around without
* checking the pgd every time.
*/
static void __init page_table_range_init(unsigned long start,
unsigned long end, pgd_t *pgd)
{
unsigned long vaddr;
start = round_down(start, PMD_SIZE);
end = round_up(end, PMD_SIZE);
for (vaddr = start; vaddr < end; vaddr += PMD_SIZE) {
pmd_t *pmd = get_pmd(pgd, vaddr);
if (pmd_none(*pmd))
assign_pte(pmd, alloc_pte());
}
}
static int __initdata ktext_hash = 1; /* .text pages */
static int __initdata kdata_hash = 1; /* .data and .bss pages */
int __write_once hash_default = 1; /* kernel allocator pages */
EXPORT_SYMBOL(hash_default);
int __write_once kstack_hash = 1; /* if no homecaching, use h4h */
/*
* CPUs to use to for striping the pages of kernel data. If hash-for-home
* is available, this is only relevant if kcache_hash sets up the
* .data and .bss to be page-homed, and we don't want the default mode
* of using the full set of kernel cpus for the striping.
*/
static __initdata struct cpumask kdata_mask;
static __initdata int kdata_arg_seen;
int __write_once kdata_huge; /* if no homecaching, small pages */
/* Combine a generic pgprot_t with cache home to get a cache-aware pgprot. */
static pgprot_t __init construct_pgprot(pgprot_t prot, int home)
{
prot = pte_set_home(prot, home);
if (home == PAGE_HOME_IMMUTABLE) {
if (ktext_hash)
prot = hv_pte_set_mode(prot, HV_PTE_MODE_CACHE_HASH_L3);
else
prot = hv_pte_set_mode(prot, HV_PTE_MODE_CACHE_NO_L3);
}
return prot;
}
/*
* For a given kernel data VA, how should it be cached?
* We return the complete pgprot_t with caching bits set.
*/
static pgprot_t __init init_pgprot(ulong address)
{
int cpu;
unsigned long page;
enum { CODE_DELTA = MEM_SV_START - PAGE_OFFSET };
/* For kdata=huge, everything is just hash-for-home. */
if (kdata_huge)
return construct_pgprot(PAGE_KERNEL, PAGE_HOME_HASH);
/* We map the aliased pages of permanent text inaccessible. */
if (address < (ulong) _sinittext - CODE_DELTA)
return PAGE_NONE;
/* We map read-only data non-coherent for performance. */
if ((address >= (ulong) __start_rodata &&
address < (ulong) __end_rodata) ||
address == (ulong) empty_zero_page) {
return construct_pgprot(PAGE_KERNEL_RO, PAGE_HOME_IMMUTABLE);
}
#ifndef __tilegx__
/* Force the atomic_locks[] array page to be hash-for-home. */
if (address == (ulong) atomic_locks)
return construct_pgprot(PAGE_KERNEL, PAGE_HOME_HASH);
#endif
/*
* Everything else that isn't data or bss is heap, so mark it
* with the initial heap home (hash-for-home, or this cpu). This
* includes any addresses after the loaded image and any address before
* _einitdata, since we already captured the case of text before
* _sinittext, and __pa(einittext) is approximately __pa(sinitdata).
*
* All the LOWMEM pages that we mark this way will get their
* struct page homecache properly marked later, in set_page_homes().
* The HIGHMEM pages we leave with a default zero for their
* homes, but with a zero free_time we don't have to actually
* do a flush action the first time we use them, either.
*/
if (address >= (ulong) _end || address < (ulong) _einitdata)
return construct_pgprot(PAGE_KERNEL, initial_heap_home());
/* Use hash-for-home if requested for data/bss. */
if (kdata_hash)
return construct_pgprot(PAGE_KERNEL, PAGE_HOME_HASH);
/*
* Otherwise we just hand out consecutive cpus. To avoid
* requiring this function to hold state, we just walk forward from
* __end_rodata by PAGE_SIZE, skipping the readonly and init data, to
* reach the requested address, while walking cpu home around
* kdata_mask. This is typically no more than a dozen or so iterations.
*/
page = (((ulong)__end_rodata) + PAGE_SIZE - 1) & PAGE_MASK;
BUG_ON(address < page || address >= (ulong)_end);
cpu = cpumask_first(&kdata_mask);
for (; page < address; page += PAGE_SIZE) {
if (page >= (ulong)&init_thread_union &&
page < (ulong)&init_thread_union + THREAD_SIZE)
continue;
if (page == (ulong)empty_zero_page)
continue;
#ifndef __tilegx__
if (page == (ulong)atomic_locks)
continue;
#endif
cpu = cpumask_next(cpu, &kdata_mask);
if (cpu == NR_CPUS)
cpu = cpumask_first(&kdata_mask);
}
return construct_pgprot(PAGE_KERNEL, cpu);
}
/*
* This function sets up how we cache the kernel text. If we have
* hash-for-home support, normally that is used instead (see the
* kcache_hash boot flag for more information). But if we end up
* using a page-based caching technique, this option sets up the
* details of that. In addition, the "ktext=nocache" option may
* always be used to disable local caching of text pages, if desired.
*/
static int __initdata ktext_arg_seen;
static int __initdata ktext_small;
static int __initdata ktext_local;
static int __initdata ktext_all;
static int __initdata ktext_nondataplane;
static int __initdata ktext_nocache;
static struct cpumask __initdata ktext_mask;
static int __init setup_ktext(char *str)
{
if (str == NULL)
return -EINVAL;
/* If you have a leading "nocache", turn off ktext caching */
if (strncmp(str, "nocache", 7) == 0) {
ktext_nocache = 1;
pr_info("ktext: disabling local caching of kernel text\n");
str += 7;
if (*str == ',')
++str;
if (*str == '\0')
return 0;
}
ktext_arg_seen = 1;
/* Default setting: use a huge page */
if (strcmp(str, "huge") == 0)
pr_info("ktext: using one huge locally cached page\n");
/* Pay TLB cost but get no cache benefit: cache small pages locally */
else if (strcmp(str, "local") == 0) {
ktext_small = 1;
ktext_local = 1;
pr_info("ktext: using small pages with local caching\n");
}
/* Neighborhood cache ktext pages on all cpus. */
else if (strcmp(str, "all") == 0) {
ktext_small = 1;
ktext_all = 1;
pr_info("ktext: using maximal caching neighborhood\n");
}
/* Neighborhood ktext pages on specified mask */
else if (cpulist_parse(str, &ktext_mask) == 0) {
char buf[NR_CPUS * 5];
cpulist_scnprintf(buf, sizeof(buf), &ktext_mask);
if (cpumask_weight(&ktext_mask) > 1) {
ktext_small = 1;
pr_info("ktext: using caching neighborhood %s "
"with small pages\n", buf);
} else {
pr_info("ktext: caching on cpu %s with one huge page\n",
buf);
}
}
else if (*str)
return -EINVAL;
return 0;
}
early_param("ktext", setup_ktext);
static inline pgprot_t ktext_set_nocache(pgprot_t prot)
{
if (!ktext_nocache)
prot = hv_pte_set_nc(prot);
else
prot = hv_pte_set_no_alloc_l2(prot);
return prot;
}
/* Temporary page table we use for staging. */
static pgd_t pgtables[PTRS_PER_PGD]
__attribute__((aligned(HV_PAGE_TABLE_ALIGN)));
/*
* This maps the physical memory to kernel virtual address space, a total
* of max_low_pfn pages, by creating page tables starting from address
* PAGE_OFFSET.
*
* This routine transitions us from using a set of compiled-in large
* pages to using some more precise caching, including removing access
* to code pages mapped at PAGE_OFFSET (executed only at MEM_SV_START)
* marking read-only data as locally cacheable, striping the remaining
* .data and .bss across all the available tiles, and removing access
* to pages above the top of RAM (thus ensuring a page fault from a bad
* virtual address rather than a hypervisor shoot down for accessing
* memory outside the assigned limits).
*/
static void __init kernel_physical_mapping_init(pgd_t *pgd_base)
{
unsigned long long irqmask;
unsigned long address, pfn;
pmd_t *pmd;
pte_t *pte;
int pte_ofs;
const struct cpumask *my_cpu_mask = cpumask_of(smp_processor_id());
struct cpumask kstripe_mask;
int rc, i;
if (ktext_arg_seen && ktext_hash) {
pr_warning("warning: \"ktext\" boot argument ignored"
" if \"kcache_hash\" sets up text hash-for-home\n");
ktext_small = 0;
}
if (kdata_arg_seen && kdata_hash) {
pr_warning("warning: \"kdata\" boot argument ignored"
" if \"kcache_hash\" sets up data hash-for-home\n");
}
if (kdata_huge && !hash_default) {
pr_warning("warning: disabling \"kdata=huge\"; requires"
" kcache_hash=all or =allbutstack\n");
kdata_huge = 0;
}
/*
* Set up a mask for cpus to use for kernel striping.
* This is normally all cpus, but minus dataplane cpus if any.
* If the dataplane covers the whole chip, we stripe over
* the whole chip too.
*/
cpumask_copy(&kstripe_mask, cpu_possible_mask);
if (!kdata_arg_seen)
kdata_mask = kstripe_mask;
/* Allocate and fill in L2 page tables */
for (i = 0; i < MAX_NUMNODES; ++i) {
#ifdef CONFIG_HIGHMEM
unsigned long end_pfn = node_lowmem_end_pfn[i];
#else
unsigned long end_pfn = node_end_pfn[i];
#endif
unsigned long end_huge_pfn = 0;
/* Pre-shatter the last huge page to allow per-cpu pages. */
if (kdata_huge)
end_huge_pfn = end_pfn - (HPAGE_SIZE >> PAGE_SHIFT);
pfn = node_start_pfn[i];
/* Allocate enough memory to hold L2 page tables for node. */
init_prealloc_ptes(i, end_pfn - pfn);
address = (unsigned long) pfn_to_kaddr(pfn);
while (pfn < end_pfn) {
BUG_ON(address & (HPAGE_SIZE-1));
pmd = get_pmd(pgtables, address);
pte = get_prealloc_pte(pfn);
if (pfn < end_huge_pfn) {
pgprot_t prot = init_pgprot(address);
*(pte_t *)pmd = pte_mkhuge(pfn_pte(pfn, prot));
for (pte_ofs = 0; pte_ofs < PTRS_PER_PTE;
pfn++, pte_ofs++, address += PAGE_SIZE)
pte[pte_ofs] = pfn_pte(pfn, prot);
} else {
if (kdata_huge)
printk(KERN_DEBUG "pre-shattered huge"
" page at %#lx\n", address);
for (pte_ofs = 0; pte_ofs < PTRS_PER_PTE;
pfn++, pte_ofs++, address += PAGE_SIZE) {
pgprot_t prot = init_pgprot(address);
pte[pte_ofs] = pfn_pte(pfn, prot);
}
assign_pte(pmd, pte);
}
}
}
/*
* Set or check ktext_map now that we have cpu_possible_mask
* and kstripe_mask to work with.
*/
if (ktext_all)
cpumask_copy(&ktext_mask, cpu_possible_mask);
else if (ktext_nondataplane)
ktext_mask = kstripe_mask;
else if (!cpumask_empty(&ktext_mask)) {
/* Sanity-check any mask that was requested */
struct cpumask bad;
cpumask_andnot(&bad, &ktext_mask, cpu_possible_mask);
cpumask_and(&ktext_mask, &ktext_mask, cpu_possible_mask);
if (!cpumask_empty(&bad)) {
char buf[NR_CPUS * 5];
cpulist_scnprintf(buf, sizeof(buf), &bad);
pr_info("ktext: not using unavailable cpus %s\n", buf);
}
if (cpumask_empty(&ktext_mask)) {
pr_warning("ktext: no valid cpus; caching on %d.\n",
smp_processor_id());
cpumask_copy(&ktext_mask,
cpumask_of(smp_processor_id()));
}
}
address = MEM_SV_START;
pmd = get_pmd(pgtables, address);
pfn = 0; /* code starts at PA 0 */
if (ktext_small) {
/* Allocate an L2 PTE for the kernel text */
int cpu = 0;
pgprot_t prot = construct_pgprot(PAGE_KERNEL_EXEC,
PAGE_HOME_IMMUTABLE);
if (ktext_local) {
if (ktext_nocache)
prot = hv_pte_set_mode(prot,
HV_PTE_MODE_UNCACHED);
else
prot = hv_pte_set_mode(prot,
HV_PTE_MODE_CACHE_NO_L3);
} else {
prot = hv_pte_set_mode(prot,
HV_PTE_MODE_CACHE_TILE_L3);
cpu = cpumask_first(&ktext_mask);
prot = ktext_set_nocache(prot);
}
BUG_ON(address != (unsigned long)_text);
pte = NULL;
for (; address < (unsigned long)_einittext;
pfn++, address += PAGE_SIZE) {
pte_ofs = pte_index(address);
if (pte_ofs == 0) {
if (pte)
assign_pte(pmd++, pte);
pte = alloc_pte();
}
if (!ktext_local) {
prot = set_remote_cache_cpu(prot, cpu);
cpu = cpumask_next(cpu, &ktext_mask);
if (cpu == NR_CPUS)
cpu = cpumask_first(&ktext_mask);
}
pte[pte_ofs] = pfn_pte(pfn, prot);
}
if (pte)
assign_pte(pmd, pte);
} else {
pte_t pteval = pfn_pte(0, PAGE_KERNEL_EXEC);
pteval = pte_mkhuge(pteval);
if (ktext_hash) {
pteval = hv_pte_set_mode(pteval,
HV_PTE_MODE_CACHE_HASH_L3);
pteval = ktext_set_nocache(pteval);
} else
if (cpumask_weight(&ktext_mask) == 1) {
pteval = set_remote_cache_cpu(pteval,
cpumask_first(&ktext_mask));
pteval = hv_pte_set_mode(pteval,
HV_PTE_MODE_CACHE_TILE_L3);
pteval = ktext_set_nocache(pteval);
} else if (ktext_nocache)
pteval = hv_pte_set_mode(pteval,
HV_PTE_MODE_UNCACHED);
else
pteval = hv_pte_set_mode(pteval,
HV_PTE_MODE_CACHE_NO_L3);
for (; address < (unsigned long)_einittext;
pfn += PFN_DOWN(HPAGE_SIZE), address += HPAGE_SIZE)
*(pte_t *)(pmd++) = pfn_pte(pfn, pteval);
}
/* Set swapper_pgprot here so it is flushed to memory right away. */
swapper_pgprot = init_pgprot((unsigned long)swapper_pg_dir);
/*
* Since we may be changing the caching of the stack and page
* table itself, we invoke an assembly helper to do the
* following steps:
*
* - flush the cache so we start with an empty slate
* - install pgtables[] as the real page table
* - flush the TLB so the new page table takes effect
*/
irqmask = interrupt_mask_save_mask();
interrupt_mask_set_mask(-1ULL);
rc = flush_and_install_context(__pa(pgtables),
init_pgprot((unsigned long)pgtables),
__this_cpu_read(current_asid),
cpumask_bits(my_cpu_mask));
interrupt_mask_restore_mask(irqmask);
BUG_ON(rc != 0);
/* Copy the page table back to the normal swapper_pg_dir. */
memcpy(pgd_base, pgtables, sizeof(pgtables));
__install_page_table(pgd_base, __this_cpu_read(current_asid),
swapper_pgprot);
/*
* We just read swapper_pgprot and thus brought it into the cache,
* with its new home & caching mode. When we start the other CPUs,
* they're going to reference swapper_pgprot via their initial fake
* VA-is-PA mappings, which cache everything locally. At that
* time, if it's in our cache with a conflicting home, the
* simulator's coherence checker will complain. So, flush it out
* of our cache; we're not going to ever use it again anyway.
*/
__insn_finv(&swapper_pgprot);
}
/*
* devmem_is_allowed() checks to see if /dev/mem access to a certain address
* is valid. The argument is a physical page number.
*
* On Tile, the only valid things for which we can just hand out unchecked
* PTEs are the kernel code and data. Anything else might change its
* homing with time, and we wouldn't know to adjust the /dev/mem PTEs.
* Note that init_thread_union is released to heap soon after boot,
* so we include it in the init data.
*
* For TILE-Gx, we might want to consider allowing access to PA
* regions corresponding to PCI space, etc.
*/
int devmem_is_allowed(unsigned long pagenr)
{
return pagenr < kaddr_to_pfn(_end) &&
!(pagenr >= kaddr_to_pfn(&init_thread_union) ||
pagenr < kaddr_to_pfn(_einitdata)) &&
!(pagenr >= kaddr_to_pfn(_sinittext) ||
pagenr <= kaddr_to_pfn(_einittext-1));
}
#ifdef CONFIG_HIGHMEM
static void __init permanent_kmaps_init(pgd_t *pgd_base)
{
pgd_t *pgd;
pud_t *pud;
pmd_t *pmd;
pte_t *pte;
unsigned long vaddr;
vaddr = PKMAP_BASE;
page_table_range_init(vaddr, vaddr + PAGE_SIZE*LAST_PKMAP, pgd_base);
pgd = swapper_pg_dir + pgd_index(vaddr);
pud = pud_offset(pgd, vaddr);
pmd = pmd_offset(pud, vaddr);
pte = pte_offset_kernel(pmd, vaddr);
pkmap_page_table = pte;
}
#endif /* CONFIG_HIGHMEM */
#ifndef CONFIG_64BIT
static void __init init_free_pfn_range(unsigned long start, unsigned long end)
{
unsigned long pfn;
struct page *page = pfn_to_page(start);
for (pfn = start; pfn < end; ) {
/* Optimize by freeing pages in large batches */
int order = __ffs(pfn);
int count, i;
struct page *p;
if (order >= MAX_ORDER)
order = MAX_ORDER-1;
count = 1 << order;
while (pfn + count > end) {
count >>= 1;
--order;
}
for (p = page, i = 0; i < count; ++i, ++p) {
__ClearPageReserved(p);
/*
* Hacky direct set to avoid unnecessary
* lock take/release for EVERY page here.
*/
p->_count.counter = 0;
p->_mapcount.counter = -1;
}
init_page_count(page);
__free_pages(page, order);
adjust_managed_page_count(page, count);
page += count;
pfn += count;
}
}
static void __init set_non_bootmem_pages_init(void)
{
struct zone *z;
for_each_zone(z) {
unsigned long start, end;
int nid = z->zone_pgdat->node_id;
#ifdef CONFIG_HIGHMEM
int idx = zone_idx(z);
#endif
start = z->zone_start_pfn;
end = start + z->spanned_pages;
start = max(start, node_free_pfn[nid]);
start = max(start, max_low_pfn);
#ifdef CONFIG_HIGHMEM
if (idx == ZONE_HIGHMEM)
totalhigh_pages += z->spanned_pages;
#endif
if (kdata_huge) {
unsigned long percpu_pfn = node_percpu_pfn[nid];
if (start < percpu_pfn && end > percpu_pfn)
end = percpu_pfn;
}
#ifdef CONFIG_PCI
if (start <= pci_reserve_start_pfn &&
end > pci_reserve_start_pfn) {
if (end > pci_reserve_end_pfn)
init_free_pfn_range(pci_reserve_end_pfn, end);
end = pci_reserve_start_pfn;
}
#endif
init_free_pfn_range(start, end);
}
}
#endif
/*
* paging_init() sets up the page tables - note that all of lowmem is
* already mapped by head.S.
*/
void __init paging_init(void)
{
#ifdef __tilegx__
pud_t *pud;
#endif
pgd_t *pgd_base = swapper_pg_dir;
kernel_physical_mapping_init(pgd_base);
/* Fixed mappings, only the page table structure has to be created. */
page_table_range_init(fix_to_virt(__end_of_fixed_addresses - 1),
FIXADDR_TOP, pgd_base);
#ifdef CONFIG_HIGHMEM
permanent_kmaps_init(pgd_base);
#endif
#ifdef __tilegx__
/*
* Since GX allocates just one pmd_t array worth of vmalloc space,
* we go ahead and allocate it statically here, then share it
* globally. As a result we don't have to worry about any task
* changing init_mm once we get up and running, and there's no
* need for e.g. vmalloc_sync_all().
*/
BUILD_BUG_ON(pgd_index(VMALLOC_START) != pgd_index(VMALLOC_END - 1));
pud = pud_offset(pgd_base + pgd_index(VMALLOC_START), VMALLOC_START);
assign_pmd(pud, alloc_pmd());
#endif
}
/*
* Walk the kernel page tables and derive the page_home() from
* the PTEs, so that set_pte() can properly validate the caching
* of all PTEs it sees.
*/
void __init set_page_homes(void)
{
}
static void __init set_max_mapnr_init(void)
{
#ifdef CONFIG_FLATMEM
max_mapnr = max_low_pfn;
#endif
}
void __init mem_init(void)
{
int i;
#ifndef __tilegx__
void *last;
#endif
#ifdef CONFIG_FLATMEM
BUG_ON(!mem_map);
#endif
#ifdef CONFIG_HIGHMEM
/* check that fixmap and pkmap do not overlap */
if (PKMAP_ADDR(LAST_PKMAP-1) >= FIXADDR_START) {
pr_err("fixmap and kmap areas overlap"
" - this will crash\n");
pr_err("pkstart: %lxh pkend: %lxh fixstart %lxh\n",
PKMAP_BASE, PKMAP_ADDR(LAST_PKMAP-1),
FIXADDR_START);
BUG();
}
#endif
set_max_mapnr_init();
/* this will put all bootmem onto the freelists */
free_all_bootmem();
#ifndef CONFIG_64BIT
/* count all remaining LOWMEM and give all HIGHMEM to page allocator */
set_non_bootmem_pages_init();
#endif
mem_init_print_info(NULL);
/*
* In debug mode, dump some interesting memory mappings.
*/
#ifdef CONFIG_HIGHMEM
printk(KERN_DEBUG " KMAP %#lx - %#lx\n",
FIXADDR_START, FIXADDR_TOP + PAGE_SIZE - 1);
printk(KERN_DEBUG " PKMAP %#lx - %#lx\n",
PKMAP_BASE, PKMAP_ADDR(LAST_PKMAP) - 1);
#endif
printk(KERN_DEBUG " VMALLOC %#lx - %#lx\n",
_VMALLOC_START, _VMALLOC_END - 1);
#ifdef __tilegx__
for (i = MAX_NUMNODES-1; i >= 0; --i) {
struct pglist_data *node = &node_data[i];
if (node->node_present_pages) {
unsigned long start = (unsigned long)
pfn_to_kaddr(node->node_start_pfn);
unsigned long end = start +
(node->node_present_pages << PAGE_SHIFT);
printk(KERN_DEBUG " MEM%d %#lx - %#lx\n",
i, start, end - 1);
}
}
#else
last = high_memory;
for (i = MAX_NUMNODES-1; i >= 0; --i) {
if ((unsigned long)vbase_map[i] != -1UL) {
printk(KERN_DEBUG " LOWMEM%d %#lx - %#lx\n",
i, (unsigned long) (vbase_map[i]),
(unsigned long) (last-1));
last = vbase_map[i];
}
}
#endif
#ifndef __tilegx__
/*
* Convert from using one lock for all atomic operations to
* one per cpu.
*/
__init_atomic_per_cpu();
#endif
}
/*
* this is for the non-NUMA, single node SMP system case.
* Specifically, in the case of x86, we will always add
* memory to the highmem for now.
*/
#ifndef CONFIG_NEED_MULTIPLE_NODES
int arch_add_memory(u64 start, u64 size)
{
struct pglist_data *pgdata = &contig_page_data;
struct zone *zone = pgdata->node_zones + MAX_NR_ZONES-1;
unsigned long start_pfn = start >> PAGE_SHIFT;
unsigned long nr_pages = size >> PAGE_SHIFT;
return __add_pages(zone, start_pfn, nr_pages);
}
int remove_memory(u64 start, u64 size)
{
return -EINVAL;
}
#ifdef CONFIG_MEMORY_HOTREMOVE
int arch_remove_memory(u64 start, u64 size)
{
/* TODO */
return -EBUSY;
}
#endif
#endif
struct kmem_cache *pgd_cache;
void __init pgtable_cache_init(void)
{
pgd_cache = kmem_cache_create("pgd", SIZEOF_PGD, SIZEOF_PGD, 0, NULL);
if (!pgd_cache)
panic("pgtable_cache_init(): Cannot create pgd cache");
}
#ifdef CONFIG_DEBUG_PAGEALLOC
static long __write_once initfree;
#else
static long __write_once initfree = 1;
#endif
/* Select whether to free (1) or mark unusable (0) the __init pages. */
static int __init set_initfree(char *str)
{
long val;
if (kstrtol(str, 0, &val) == 0) {
initfree = val;
pr_info("initfree: %s free init pages\n",
initfree ? "will" : "won't");
}
return 1;
}
__setup("initfree=", set_initfree);
static void free_init_pages(char *what, unsigned long begin, unsigned long end)
{
unsigned long addr = (unsigned long) begin;
if (kdata_huge && !initfree) {
pr_warning("Warning: ignoring initfree=0:"
" incompatible with kdata=huge\n");
initfree = 1;
}
end = (end + PAGE_SIZE - 1) & PAGE_MASK;
local_flush_tlb_pages(NULL, begin, PAGE_SIZE, end - begin);
for (addr = begin; addr < end; addr += PAGE_SIZE) {
/*
* Note we just reset the home here directly in the
* page table. We know this is safe because our caller
* just flushed the caches on all the other cpus,
* and they won't be touching any of these pages.
*/
int pfn = kaddr_to_pfn((void *)addr);
struct page *page = pfn_to_page(pfn);
pte_t *ptep = virt_to_kpte(addr);
if (!initfree) {
/*
* If debugging page accesses then do not free
* this memory but mark them not present - any
* buggy init-section access will create a
* kernel page fault:
*/
pte_clear(&init_mm, addr, ptep);
continue;
}
if (pte_huge(*ptep))
BUG_ON(!kdata_huge);
else
set_pte_at(&init_mm, addr, ptep,
pfn_pte(pfn, PAGE_KERNEL));
memset((void *)addr, POISON_FREE_INITMEM, PAGE_SIZE);
free_reserved_page(page);
}
pr_info("Freeing %s: %ldk freed\n", what, (end - begin) >> 10);
}
void free_initmem(void)
{
const unsigned long text_delta = MEM_SV_START - PAGE_OFFSET;
/*
* Evict the cache on all cores to avoid incoherence.
* We are guaranteed that no one will touch the init pages any more.
*/
homecache_evict(&cpu_cacheable_map);
/* Free the data pages that we won't use again after init. */
free_init_pages("unused kernel data",
(unsigned long)_sinitdata,
(unsigned long)_einitdata);
/*
* Free the pages mapped from 0xc0000000 that correspond to code
* pages from MEM_SV_START that we won't use again after init.
*/
free_init_pages("unused kernel text",
(unsigned long)_sinittext - text_delta,
(unsigned long)_einittext - text_delta);
/* Do a global TLB flush so everyone sees the changes. */
flush_tlb_all();
}
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