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linux-sg2042/arch/parisc/mm/init.c

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// SPDX-License-Identifier: GPL-2.0
/*
* linux/arch/parisc/mm/init.c
*
* Copyright (C) 1995 Linus Torvalds
* Copyright 1999 SuSE GmbH
* changed by Philipp Rumpf
* Copyright 1999 Philipp Rumpf (prumpf@tux.org)
* Copyright 2004 Randolph Chung (tausq@debian.org)
* Copyright 2006-2007 Helge Deller (deller@gmx.de)
*
*/
#include <linux/module.h>
#include <linux/mm.h>
#include <linux/memblock.h>
#include <linux/gfp.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/initrd.h>
#include <linux/swap.h>
#include <linux/unistd.h>
#include <linux/nodemask.h> /* for node_online_map */
#include <linux/pagemap.h> /* for release_pages */
#include <linux/compat.h>
#include <asm/pgalloc.h>
#include <asm/pgtable.h>
#include <asm/tlb.h>
#include <asm/pdc_chassis.h>
#include <asm/mmzone.h>
#include <asm/sections.h>
#include <asm/msgbuf.h>
#include <asm/sparsemem.h>
extern int data_start;
extern void parisc_kernel_start(void); /* Kernel entry point in head.S */
#if CONFIG_PGTABLE_LEVELS == 3
/* NOTE: This layout exactly conforms to the hybrid L2/L3 page table layout
* with the first pmd adjacent to the pgd and below it. gcc doesn't actually
* guarantee that global objects will be laid out in memory in the same order
* as the order of declaration, so put these in different sections and use
* the linker script to order them. */
pmd_t pmd0[PTRS_PER_PMD] __attribute__ ((__section__ (".data..vm0.pmd"), aligned(PAGE_SIZE)));
#endif
pgd_t swapper_pg_dir[PTRS_PER_PGD] __attribute__ ((__section__ (".data..vm0.pgd"), aligned(PAGE_SIZE)));
pte_t pg0[PT_INITIAL * PTRS_PER_PTE] __attribute__ ((__section__ (".data..vm0.pte"), aligned(PAGE_SIZE)));
static struct resource data_resource = {
.name = "Kernel data",
.flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
};
static struct resource code_resource = {
.name = "Kernel code",
.flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
};
static struct resource pdcdata_resource = {
.name = "PDC data (Page Zero)",
.start = 0,
.end = 0x9ff,
.flags = IORESOURCE_BUSY | IORESOURCE_MEM,
};
static struct resource sysram_resources[MAX_PHYSMEM_RANGES] __ro_after_init;
/* The following array is initialized from the firmware specific
* information retrieved in kernel/inventory.c.
*/
physmem_range_t pmem_ranges[MAX_PHYSMEM_RANGES] __initdata;
int npmem_ranges __initdata;
#ifdef CONFIG_64BIT
#define MAX_MEM (1UL << MAX_PHYSMEM_BITS)
#else /* !CONFIG_64BIT */
#define MAX_MEM (3584U*1024U*1024U)
#endif /* !CONFIG_64BIT */
static unsigned long mem_limit __read_mostly = MAX_MEM;
static void __init mem_limit_func(void)
{
char *cp, *end;
unsigned long limit;
/* We need this before __setup() functions are called */
limit = MAX_MEM;
for (cp = boot_command_line; *cp; ) {
if (memcmp(cp, "mem=", 4) == 0) {
cp += 4;
limit = memparse(cp, &end);
if (end != cp)
break;
cp = end;
} else {
while (*cp != ' ' && *cp)
++cp;
while (*cp == ' ')
++cp;
}
}
if (limit < mem_limit)
mem_limit = limit;
}
#define MAX_GAP (0x40000000UL >> PAGE_SHIFT)
static void __init setup_bootmem(void)
{
unsigned long mem_max;
#ifndef CONFIG_SPARSEMEM
physmem_range_t pmem_holes[MAX_PHYSMEM_RANGES - 1];
int npmem_holes;
#endif
int i, sysram_resource_count;
disable_sr_hashing(); /* Turn off space register hashing */
/*
* Sort the ranges. Since the number of ranges is typically
* small, and performance is not an issue here, just do
* a simple insertion sort.
*/
for (i = 1; i < npmem_ranges; i++) {
int j;
for (j = i; j > 0; j--) {
physmem_range_t tmp;
if (pmem_ranges[j-1].start_pfn <
pmem_ranges[j].start_pfn) {
break;
}
tmp = pmem_ranges[j-1];
pmem_ranges[j-1] = pmem_ranges[j];
pmem_ranges[j] = tmp;
}
}
#ifndef CONFIG_SPARSEMEM
/*
* Throw out ranges that are too far apart (controlled by
* MAX_GAP).
*/
for (i = 1; i < npmem_ranges; i++) {
if (pmem_ranges[i].start_pfn -
(pmem_ranges[i-1].start_pfn +
pmem_ranges[i-1].pages) > MAX_GAP) {
npmem_ranges = i;
printk("Large gap in memory detected (%ld pages). "
"Consider turning on CONFIG_SPARSEMEM\n",
pmem_ranges[i].start_pfn -
(pmem_ranges[i-1].start_pfn +
pmem_ranges[i-1].pages));
break;
}
}
#endif
/* Print the memory ranges */
pr_info("Memory Ranges:\n");
for (i = 0; i < npmem_ranges; i++) {
struct resource *res = &sysram_resources[i];
unsigned long start;
unsigned long size;
size = (pmem_ranges[i].pages << PAGE_SHIFT);
start = (pmem_ranges[i].start_pfn << PAGE_SHIFT);
pr_info("%2d) Start 0x%016lx End 0x%016lx Size %6ld MB\n",
i, start, start + (size - 1), size >> 20);
/* request memory resource */
res->name = "System RAM";
res->start = start;
res->end = start + size - 1;
res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
request_resource(&iomem_resource, res);
}
sysram_resource_count = npmem_ranges;
/*
* For 32 bit kernels we limit the amount of memory we can
* support, in order to preserve enough kernel address space
* for other purposes. For 64 bit kernels we don't normally
* limit the memory, but this mechanism can be used to
* artificially limit the amount of memory (and it is written
* to work with multiple memory ranges).
*/
mem_limit_func(); /* check for "mem=" argument */
mem_max = 0;
for (i = 0; i < npmem_ranges; i++) {
unsigned long rsize;
rsize = pmem_ranges[i].pages << PAGE_SHIFT;
if ((mem_max + rsize) > mem_limit) {
printk(KERN_WARNING "Memory truncated to %ld MB\n", mem_limit >> 20);
if (mem_max == mem_limit)
npmem_ranges = i;
else {
pmem_ranges[i].pages = (mem_limit >> PAGE_SHIFT)
- (mem_max >> PAGE_SHIFT);
npmem_ranges = i + 1;
mem_max = mem_limit;
}
break;
}
mem_max += rsize;
}
printk(KERN_INFO "Total Memory: %ld MB\n",mem_max >> 20);
#ifndef CONFIG_SPARSEMEM
/* Merge the ranges, keeping track of the holes */
{
unsigned long end_pfn;
unsigned long hole_pages;
npmem_holes = 0;
end_pfn = pmem_ranges[0].start_pfn + pmem_ranges[0].pages;
for (i = 1; i < npmem_ranges; i++) {
hole_pages = pmem_ranges[i].start_pfn - end_pfn;
if (hole_pages) {
pmem_holes[npmem_holes].start_pfn = end_pfn;
pmem_holes[npmem_holes++].pages = hole_pages;
end_pfn += hole_pages;
}
end_pfn += pmem_ranges[i].pages;
}
pmem_ranges[0].pages = end_pfn - pmem_ranges[0].start_pfn;
npmem_ranges = 1;
}
#endif
/*
* Initialize and free the full range of memory in each range.
*/
max_pfn = 0;
for (i = 0; i < npmem_ranges; i++) {
unsigned long start_pfn;
unsigned long npages;
unsigned long start;
unsigned long size;
start_pfn = pmem_ranges[i].start_pfn;
npages = pmem_ranges[i].pages;
start = start_pfn << PAGE_SHIFT;
size = npages << PAGE_SHIFT;
/* add system RAM memblock */
memblock_add(start, size);
if ((start_pfn + npages) > max_pfn)
max_pfn = start_pfn + npages;
}
/*
* We can't use memblock top-down allocations because we only
* created the initial mapping up to KERNEL_INITIAL_SIZE in
* the assembly bootup code.
*/
memblock_set_bottom_up(true);
/* IOMMU is always used to access "high mem" on those boxes
* that can support enough mem that a PCI device couldn't
* directly DMA to any physical addresses.
* ISA DMA support will need to revisit this.
*/
max_low_pfn = max_pfn;
/* reserve PAGE0 pdc memory, kernel text/data/bss & bootmap */
#define PDC_CONSOLE_IO_IODC_SIZE 32768
memblock_reserve(0UL, (unsigned long)(PAGE0->mem_free +
PDC_CONSOLE_IO_IODC_SIZE));
memblock_reserve(__pa(KERNEL_BINARY_TEXT_START),
(unsigned long)(_end - KERNEL_BINARY_TEXT_START));
#ifndef CONFIG_SPARSEMEM
/* reserve the holes */
for (i = 0; i < npmem_holes; i++) {
memblock_reserve((pmem_holes[i].start_pfn << PAGE_SHIFT),
(pmem_holes[i].pages << PAGE_SHIFT));
}
#endif
#ifdef CONFIG_BLK_DEV_INITRD
if (initrd_start) {
printk(KERN_INFO "initrd: %08lx-%08lx\n", initrd_start, initrd_end);
if (__pa(initrd_start) < mem_max) {
unsigned long initrd_reserve;
if (__pa(initrd_end) > mem_max) {
initrd_reserve = mem_max - __pa(initrd_start);
} else {
initrd_reserve = initrd_end - initrd_start;
}
initrd_below_start_ok = 1;
printk(KERN_INFO "initrd: reserving %08lx-%08lx (mem_max %08lx)\n", __pa(initrd_start), __pa(initrd_start) + initrd_reserve, mem_max);
memblock_reserve(__pa(initrd_start), initrd_reserve);
}
}
#endif
data_resource.start = virt_to_phys(&data_start);
data_resource.end = virt_to_phys(_end) - 1;
code_resource.start = virt_to_phys(_text);
code_resource.end = virt_to_phys(&data_start)-1;
/* We don't know which region the kernel will be in, so try
* all of them.
*/
for (i = 0; i < sysram_resource_count; i++) {
struct resource *res = &sysram_resources[i];
request_resource(res, &code_resource);
request_resource(res, &data_resource);
}
request_resource(&sysram_resources[0], &pdcdata_resource);
/* Initialize Page Deallocation Table (PDT) and check for bad memory. */
pdc_pdt_init();
memblock_allow_resize();
memblock_dump_all();
}
static bool kernel_set_to_readonly;
static void __init map_pages(unsigned long start_vaddr,
unsigned long start_paddr, unsigned long size,
pgprot_t pgprot, int force)
{
pmd_t *pmd;
pte_t *pg_table;
unsigned long end_paddr;
unsigned long start_pmd;
unsigned long start_pte;
unsigned long tmp1;
unsigned long tmp2;
unsigned long address;
unsigned long vaddr;
unsigned long ro_start;
unsigned long ro_end;
unsigned long kernel_start, kernel_end;
ro_start = __pa((unsigned long)_text);
ro_end = __pa((unsigned long)&data_start);
kernel_start = __pa((unsigned long)&__init_begin);
kernel_end = __pa((unsigned long)&_end);
end_paddr = start_paddr + size;
/* for 2-level configuration PTRS_PER_PMD is 0 so start_pmd will be 0 */
start_pmd = ((start_vaddr >> PMD_SHIFT) & (PTRS_PER_PMD - 1));
start_pte = ((start_vaddr >> PAGE_SHIFT) & (PTRS_PER_PTE - 1));
address = start_paddr;
vaddr = start_vaddr;
while (address < end_paddr) {
pgd_t *pgd = pgd_offset_k(vaddr);
p4d_t *p4d = p4d_offset(pgd, vaddr);
pud_t *pud = pud_offset(p4d, vaddr);
#if CONFIG_PGTABLE_LEVELS == 3
if (pud_none(*pud)) {
pmd = memblock_alloc(PAGE_SIZE << PMD_ORDER,
PAGE_SIZE << PMD_ORDER);
if (!pmd)
panic("pmd allocation failed.\n");
pud_populate(NULL, pud, pmd);
}
#endif
pmd = pmd_offset(pud, vaddr);
for (tmp1 = start_pmd; tmp1 < PTRS_PER_PMD; tmp1++, pmd++) {
if (pmd_none(*pmd)) {
pg_table = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
if (!pg_table)
panic("page table allocation failed\n");
pmd_populate_kernel(NULL, pmd, pg_table);
}
pg_table = pte_offset_kernel(pmd, vaddr);
for (tmp2 = start_pte; tmp2 < PTRS_PER_PTE; tmp2++, pg_table++) {
pte_t pte;
pgprot_t prot;
bool huge = false;
if (force) {
prot = pgprot;
} else if (address < kernel_start || address >= kernel_end) {
/* outside kernel memory */
prot = PAGE_KERNEL;
} else if (!kernel_set_to_readonly) {
/* still initializing, allow writing to RO memory */
prot = PAGE_KERNEL_RWX;
huge = true;
} else if (address >= ro_start) {
/* Code (ro) and Data areas */
prot = (address < ro_end) ?
PAGE_KERNEL_EXEC : PAGE_KERNEL;
huge = true;
} else {
prot = PAGE_KERNEL;
}
pte = __mk_pte(address, prot);
if (huge)
pte = pte_mkhuge(pte);
if (address >= end_paddr)
break;
set_pte(pg_table, pte);
address += PAGE_SIZE;
vaddr += PAGE_SIZE;
}
start_pte = 0;
if (address >= end_paddr)
break;
}
start_pmd = 0;
}
}
void __init set_kernel_text_rw(int enable_read_write)
{
unsigned long start = (unsigned long) __init_begin;
unsigned long end = (unsigned long) &data_start;
map_pages(start, __pa(start), end-start,
PAGE_KERNEL_RWX, enable_read_write ? 1:0);
/* force the kernel to see the new page table entries */
flush_cache_all();
flush_tlb_all();
}
void __ref free_initmem(void)
{
unsigned long init_begin = (unsigned long)__init_begin;
unsigned long init_end = (unsigned long)__init_end;
unsigned long kernel_end = (unsigned long)&_end;
/* Remap kernel text and data, but do not touch init section yet. */
kernel_set_to_readonly = true;
map_pages(init_end, __pa(init_end), kernel_end - init_end,
PAGE_KERNEL, 0);
/* The init text pages are marked R-X. We have to
* flush the icache and mark them RW-
*
* This is tricky, because map_pages is in the init section.
* Do a dummy remap of the data section first (the data
* section is already PAGE_KERNEL) to pull in the TLB entries
* for map_kernel */
map_pages(init_begin, __pa(init_begin), init_end - init_begin,
PAGE_KERNEL_RWX, 1);
/* now remap at PAGE_KERNEL since the TLB is pre-primed to execute
* map_pages */
map_pages(init_begin, __pa(init_begin), init_end - init_begin,
PAGE_KERNEL, 1);
/* force the kernel to see the new TLB entries */
__flush_tlb_range(0, init_begin, kernel_end);
/* finally dump all the instructions which were cached, since the
* pages are no-longer executable */
flush_icache_range(init_begin, init_end);
free_initmem_default(POISON_FREE_INITMEM);
/* set up a new led state on systems shipped LED State panel */
pdc_chassis_send_status(PDC_CHASSIS_DIRECT_BCOMPLETE);
}
#ifdef CONFIG_STRICT_KERNEL_RWX
void mark_rodata_ro(void)
{
/* rodata memory was already mapped with KERNEL_RO access rights by
pagetable_init() and map_pages(). No need to do additional stuff here */
unsigned long roai_size = __end_ro_after_init - __start_ro_after_init;
pr_info("Write protected read-only-after-init data: %luk\n", roai_size >> 10);
}
#endif
/*
* Just an arbitrary offset to serve as a "hole" between mapping areas
* (between top of physical memory and a potential pcxl dma mapping
* area, and below the vmalloc mapping area).
*
* The current 32K value just means that there will be a 32K "hole"
* between mapping areas. That means that any out-of-bounds memory
* accesses will hopefully be caught. The vmalloc() routines leaves
* a hole of 4kB between each vmalloced area for the same reason.
*/
/* Leave room for gateway page expansion */
#if KERNEL_MAP_START < GATEWAY_PAGE_SIZE
#error KERNEL_MAP_START is in gateway reserved region
#endif
#define MAP_START (KERNEL_MAP_START)
#define VM_MAP_OFFSET (32*1024)
#define SET_MAP_OFFSET(x) ((void *)(((unsigned long)(x) + VM_MAP_OFFSET) \
& ~(VM_MAP_OFFSET-1)))
void *parisc_vmalloc_start __ro_after_init;
EXPORT_SYMBOL(parisc_vmalloc_start);
#ifdef CONFIG_PA11
unsigned long pcxl_dma_start __ro_after_init;
#endif
void __init mem_init(void)
{
/* Do sanity checks on IPC (compat) structures */
BUILD_BUG_ON(sizeof(struct ipc64_perm) != 48);
#ifndef CONFIG_64BIT
BUILD_BUG_ON(sizeof(struct semid64_ds) != 80);
BUILD_BUG_ON(sizeof(struct msqid64_ds) != 104);
BUILD_BUG_ON(sizeof(struct shmid64_ds) != 104);
#endif
#ifdef CONFIG_COMPAT
BUILD_BUG_ON(sizeof(struct compat_ipc64_perm) != sizeof(struct ipc64_perm));
BUILD_BUG_ON(sizeof(struct compat_semid64_ds) != 80);
BUILD_BUG_ON(sizeof(struct compat_msqid64_ds) != 104);
BUILD_BUG_ON(sizeof(struct compat_shmid64_ds) != 104);
#endif
/* Do sanity checks on page table constants */
BUILD_BUG_ON(PTE_ENTRY_SIZE != sizeof(pte_t));
BUILD_BUG_ON(PMD_ENTRY_SIZE != sizeof(pmd_t));
BUILD_BUG_ON(PGD_ENTRY_SIZE != sizeof(pgd_t));
BUILD_BUG_ON(PAGE_SHIFT + BITS_PER_PTE + BITS_PER_PMD + BITS_PER_PGD
> BITS_PER_LONG);
high_memory = __va((max_pfn << PAGE_SHIFT));
set_max_mapnr(page_to_pfn(virt_to_page(high_memory - 1)) + 1);
memblock_free_all();
#ifdef CONFIG_PA11
if (boot_cpu_data.cpu_type == pcxl2 || boot_cpu_data.cpu_type == pcxl) {
pcxl_dma_start = (unsigned long)SET_MAP_OFFSET(MAP_START);
parisc_vmalloc_start = SET_MAP_OFFSET(pcxl_dma_start
+ PCXL_DMA_MAP_SIZE);
} else
#endif
parisc_vmalloc_start = SET_MAP_OFFSET(MAP_START);
mem_init_print_info(NULL);
#if 0
/*
* Do not expose the virtual kernel memory layout to userspace.
* But keep code for debugging purposes.
*/
printk("virtual kernel memory layout:\n"
" vmalloc : 0x%px - 0x%px (%4ld MB)\n"
" fixmap : 0x%px - 0x%px (%4ld kB)\n"
" memory : 0x%px - 0x%px (%4ld MB)\n"
" .init : 0x%px - 0x%px (%4ld kB)\n"
" .data : 0x%px - 0x%px (%4ld kB)\n"
" .text : 0x%px - 0x%px (%4ld kB)\n",
(void*)VMALLOC_START, (void*)VMALLOC_END,
(VMALLOC_END - VMALLOC_START) >> 20,
(void *)FIXMAP_START, (void *)(FIXMAP_START + FIXMAP_SIZE),
(unsigned long)(FIXMAP_SIZE / 1024),
__va(0), high_memory,
((unsigned long)high_memory - (unsigned long)__va(0)) >> 20,
__init_begin, __init_end,
((unsigned long)__init_end - (unsigned long)__init_begin) >> 10,
_etext, _edata,
((unsigned long)_edata - (unsigned long)_etext) >> 10,
_text, _etext,
((unsigned long)_etext - (unsigned long)_text) >> 10);
#endif
}
unsigned long *empty_zero_page __ro_after_init;
EXPORT_SYMBOL(empty_zero_page);
/*
* pagetable_init() sets up the page tables
*
* Note that gateway_init() places the Linux gateway page at page 0.
* Since gateway pages cannot be dereferenced this has the desirable
* side effect of trapping those pesky NULL-reference errors in the
* kernel.
*/
static void __init pagetable_init(void)
{
int range;
/* Map each physical memory range to its kernel vaddr */
for (range = 0; range < npmem_ranges; range++) {
unsigned long start_paddr;
unsigned long end_paddr;
unsigned long size;
start_paddr = pmem_ranges[range].start_pfn << PAGE_SHIFT;
size = pmem_ranges[range].pages << PAGE_SHIFT;
end_paddr = start_paddr + size;
map_pages((unsigned long)__va(start_paddr), start_paddr,
size, PAGE_KERNEL, 0);
}
#ifdef CONFIG_BLK_DEV_INITRD
if (initrd_end && initrd_end > mem_limit) {
printk(KERN_INFO "initrd: mapping %08lx-%08lx\n", initrd_start, initrd_end);
map_pages(initrd_start, __pa(initrd_start),
initrd_end - initrd_start, PAGE_KERNEL, 0);
}
#endif
empty_zero_page = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
if (!empty_zero_page)
panic("zero page allocation failed.\n");
}
static void __init gateway_init(void)
{
unsigned long linux_gateway_page_addr;
/* FIXME: This is 'const' in order to trick the compiler
into not treating it as DP-relative data. */
extern void * const linux_gateway_page;
linux_gateway_page_addr = LINUX_GATEWAY_ADDR & PAGE_MASK;
/*
* Setup Linux Gateway page.
*
* The Linux gateway page will reside in kernel space (on virtual
* page 0), so it doesn't need to be aliased into user space.
*/
map_pages(linux_gateway_page_addr, __pa(&linux_gateway_page),
PAGE_SIZE, PAGE_GATEWAY, 1);
}
static void __init parisc_bootmem_free(void)
{
unsigned long zones_size[MAX_NR_ZONES] = { 0, };
unsigned long holes_size[MAX_NR_ZONES] = { 0, };
unsigned long mem_start_pfn = ~0UL, mem_end_pfn = 0, mem_size_pfn = 0;
int i;
for (i = 0; i < npmem_ranges; i++) {
unsigned long start = pmem_ranges[i].start_pfn;
unsigned long size = pmem_ranges[i].pages;
unsigned long end = start + size;
if (mem_start_pfn > start)
mem_start_pfn = start;
if (mem_end_pfn < end)
mem_end_pfn = end;
mem_size_pfn += size;
}
zones_size[0] = mem_end_pfn - mem_start_pfn;
holes_size[0] = zones_size[0] - mem_size_pfn;
free_area_init_node(0, zones_size, mem_start_pfn, holes_size);
}
void __init paging_init(void)
{
setup_bootmem();
pagetable_init();
gateway_init();
flush_cache_all_local(); /* start with known state */
flush_tlb_all_local(NULL);
/*
* Mark all memblocks as present for sparsemem using
* memory_present() and then initialize sparsemem.
*/
memblocks_present();
sparse_init();
parisc_bootmem_free();
}
#ifdef CONFIG_PA20
/*
* Currently, all PA20 chips have 18 bit protection IDs, which is the
* limiting factor (space ids are 32 bits).
*/
#define NR_SPACE_IDS 262144
#else
/*
* Currently we have a one-to-one relationship between space IDs and
* protection IDs. Older parisc chips (PCXS, PCXT, PCXL, PCXL2) only
* support 15 bit protection IDs, so that is the limiting factor.
* PCXT' has 18 bit protection IDs, but only 16 bit spaceids, so it's
* probably not worth the effort for a special case here.
*/
#define NR_SPACE_IDS 32768
#endif /* !CONFIG_PA20 */
#define RECYCLE_THRESHOLD (NR_SPACE_IDS / 2)
#define SID_ARRAY_SIZE (NR_SPACE_IDS / (8 * sizeof(long)))
static unsigned long space_id[SID_ARRAY_SIZE] = { 1 }; /* disallow space 0 */
static unsigned long dirty_space_id[SID_ARRAY_SIZE];
static unsigned long space_id_index;
static unsigned long free_space_ids = NR_SPACE_IDS - 1;
static unsigned long dirty_space_ids = 0;
static DEFINE_SPINLOCK(sid_lock);
unsigned long alloc_sid(void)
{
unsigned long index;
spin_lock(&sid_lock);
if (free_space_ids == 0) {
if (dirty_space_ids != 0) {
spin_unlock(&sid_lock);
flush_tlb_all(); /* flush_tlb_all() calls recycle_sids() */
spin_lock(&sid_lock);
}
BUG_ON(free_space_ids == 0);
}
free_space_ids--;
index = find_next_zero_bit(space_id, NR_SPACE_IDS, space_id_index);
space_id[index >> SHIFT_PER_LONG] |= (1L << (index & (BITS_PER_LONG - 1)));
space_id_index = index;
spin_unlock(&sid_lock);
return index << SPACEID_SHIFT;
}
void free_sid(unsigned long spaceid)
{
unsigned long index = spaceid >> SPACEID_SHIFT;
unsigned long *dirty_space_offset;
dirty_space_offset = dirty_space_id + (index >> SHIFT_PER_LONG);
index &= (BITS_PER_LONG - 1);
spin_lock(&sid_lock);
BUG_ON(*dirty_space_offset & (1L << index)); /* attempt to free space id twice */
*dirty_space_offset |= (1L << index);
dirty_space_ids++;
spin_unlock(&sid_lock);
}
#ifdef CONFIG_SMP
static void get_dirty_sids(unsigned long *ndirtyptr,unsigned long *dirty_array)
{
int i;
/* NOTE: sid_lock must be held upon entry */
*ndirtyptr = dirty_space_ids;
if (dirty_space_ids != 0) {
for (i = 0; i < SID_ARRAY_SIZE; i++) {
dirty_array[i] = dirty_space_id[i];
dirty_space_id[i] = 0;
}
dirty_space_ids = 0;
}
return;
}
static void recycle_sids(unsigned long ndirty,unsigned long *dirty_array)
{
int i;
/* NOTE: sid_lock must be held upon entry */
if (ndirty != 0) {
for (i = 0; i < SID_ARRAY_SIZE; i++) {
space_id[i] ^= dirty_array[i];
}
free_space_ids += ndirty;
space_id_index = 0;
}
}
#else /* CONFIG_SMP */
static void recycle_sids(void)
{
int i;
/* NOTE: sid_lock must be held upon entry */
if (dirty_space_ids != 0) {
for (i = 0; i < SID_ARRAY_SIZE; i++) {
space_id[i] ^= dirty_space_id[i];
dirty_space_id[i] = 0;
}
free_space_ids += dirty_space_ids;
dirty_space_ids = 0;
space_id_index = 0;
}
}
#endif
/*
* flush_tlb_all() calls recycle_sids(), since whenever the entire tlb is
* purged, we can safely reuse the space ids that were released but
* not flushed from the tlb.
*/
#ifdef CONFIG_SMP
static unsigned long recycle_ndirty;
static unsigned long recycle_dirty_array[SID_ARRAY_SIZE];
static unsigned int recycle_inuse;
void flush_tlb_all(void)
{
int do_recycle;
__inc_irq_stat(irq_tlb_count);
do_recycle = 0;
spin_lock(&sid_lock);
if (dirty_space_ids > RECYCLE_THRESHOLD) {
BUG_ON(recycle_inuse); /* FIXME: Use a semaphore/wait queue here */
get_dirty_sids(&recycle_ndirty,recycle_dirty_array);
recycle_inuse++;
do_recycle++;
}
spin_unlock(&sid_lock);
on_each_cpu(flush_tlb_all_local, NULL, 1);
if (do_recycle) {
spin_lock(&sid_lock);
recycle_sids(recycle_ndirty,recycle_dirty_array);
recycle_inuse = 0;
spin_unlock(&sid_lock);
}
}
#else
void flush_tlb_all(void)
{
__inc_irq_stat(irq_tlb_count);
spin_lock(&sid_lock);
flush_tlb_all_local(NULL);
recycle_sids();
spin_unlock(&sid_lock);
}
#endif
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