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Linux-2.6.12-rc2

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Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
This commit is contained in:
Linus Torvalds
2005-04-16 15:20:36 -07:00
commit 1da177e4c3
17291 changed files with 6718755 additions and 0 deletions
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6
arch/cris/mm/Makefile Normal file
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#
# Makefile for the linux cris-specific parts of the memory manager.
#
obj-y := init.o fault.o tlb.o ioremap.o

387
arch/cris/mm/fault.c Normal file
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/*
* linux/arch/cris/mm/fault.c
*
* Copyright (C) 2000, 2001 Axis Communications AB
*
* Authors: Bjorn Wesen
*
* $Log: fault.c,v $
* Revision 1.11 2004/05/14 07:58:05 starvik
* Merge of changes from 2.4
*
* Revision 1.10 2003/10/27 14:51:24 starvik
* Removed debugcode
*
* Revision 1.9 2003/10/27 14:50:42 starvik
* Changed do_page_fault signature
*
* Revision 1.8 2003/07/04 13:02:48 tobiasa
* Moved code snippet from arch/cris/mm/fault.c that searches for fixup code
* to seperate function in arch-specific files.
*
* Revision 1.7 2003/01/22 06:48:38 starvik
* Fixed warnings issued by GCC 3.2.1
*
* Revision 1.6 2003/01/09 14:42:52 starvik
* Merge of Linux 2.5.55
*
* Revision 1.5 2002/12/11 14:44:48 starvik
* Extracted v10 (ETRAX 100LX) specific stuff to arch/cris/arch-v10/mm
*
* Revision 1.4 2002/11/13 15:10:28 starvik
* pte_offset has been renamed to pte_offset_kernel
*
* Revision 1.3 2002/11/05 06:45:13 starvik
* Merge of Linux 2.5.45
*
* Revision 1.2 2001/12/18 13:35:22 bjornw
* Applied the 2.4.13->2.4.16 CRIS patch to 2.5.1 (is a copy of 2.4.15).
*
* Revision 1.20 2001/11/22 13:34:06 bjornw
* * Bug workaround (LX TR89): force a rerun of the whole of an interrupted
* unaligned write, because the second half of the write will be corrupted
* otherwise. Affected unaligned writes spanning not-yet mapped pages.
* * Optimization: use the wr_rd bit in R_MMU_CAUSE to know whether a miss
* was due to a read or a write (before we didn't know this until the next
* restart of the interrupted instruction, thus wasting one fault-irq)
*
* Revision 1.19 2001/11/12 19:02:10 pkj
* Fixed compiler warnings.
*
* Revision 1.18 2001/07/18 22:14:32 bjornw
* Enable interrupts in the bulk of do_page_fault
*
* Revision 1.17 2001/07/18 13:07:23 bjornw
* * Detect non-existant PTE's in vmalloc pmd synchronization
* * Remove comment about fast-paths for VMALLOC_START etc, because all that
* was totally bogus anyway it turned out :)
* * Fix detection of vmalloc-area synchronization
* * Add some comments
*
* Revision 1.16 2001/06/13 00:06:08 bjornw
* current_pgd should be volatile
*
* Revision 1.15 2001/06/13 00:02:23 bjornw
* Use a separate variable to store the current pgd to avoid races in schedule
*
* Revision 1.14 2001/05/16 17:41:07 hp
* Last comment tweak further tweaked.
*
* Revision 1.13 2001/05/15 00:58:44 hp
* Expand a bit on the comment why we compare address >= TASK_SIZE rather
* than >= VMALLOC_START.
*
* Revision 1.12 2001/04/04 10:51:14 bjornw
* mmap_sem is grabbed for reading
*
* Revision 1.11 2001/03/23 07:36:07 starvik
* Corrected according to review remarks
*
* Revision 1.10 2001/03/21 16:10:11 bjornw
* CRIS_FRAME_FIXUP not needed anymore, use FRAME_NORMAL
*
* Revision 1.9 2001/03/05 13:22:20 bjornw
* Spell-fix and fix in vmalloc_fault handling
*
* Revision 1.8 2000/11/22 14:45:31 bjornw
* * 2.4.0-test10 removed the set_pgdir instantaneous kernel global mapping
* into all processes. Instead we fill in the missing PTE entries on demand.
*
* Revision 1.7 2000/11/21 16:39:09 bjornw
* fixup switches frametype
*
* Revision 1.6 2000/11/17 16:54:08 bjornw
* More detailed siginfo reporting
*
*
*/
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <asm/uaccess.h>
extern int find_fixup_code(struct pt_regs *);
extern void die_if_kernel(const char *, struct pt_regs *, long);
/* debug of low-level TLB reload */
#undef DEBUG
#ifdef DEBUG
#define D(x) x
#else
#define D(x)
#endif
/* debug of higher-level faults */
#define DPG(x)
/* current active page directory */
volatile pgd_t *current_pgd;
/*
* This routine handles page faults. It determines the address,
* and the problem, and then passes it off to one of the appropriate
* routines.
*
* Notice that the address we're given is aligned to the page the fault
* occurred in, since we only get the PFN in R_MMU_CAUSE not the complete
* address.
*
* error_code:
* bit 0 == 0 means no page found, 1 means protection fault
* bit 1 == 0 means read, 1 means write
*
* If this routine detects a bad access, it returns 1, otherwise it
* returns 0.
*/
asmlinkage void
do_page_fault(unsigned long address, struct pt_regs *regs,
int protection, int writeaccess)
{
struct task_struct *tsk;
struct mm_struct *mm;
struct vm_area_struct * vma;
siginfo_t info;
D(printk("Page fault for %X at %X, prot %d write %d\n",
address, regs->erp, protection, writeaccess));
tsk = current;
/*
* We fault-in kernel-space virtual memory on-demand. The
* 'reference' page table is init_mm.pgd.
*
* NOTE! We MUST NOT take any locks for this case. We may
* be in an interrupt or a critical region, and should
* only copy the information from the master page table,
* nothing more.
*
* NOTE2: This is done so that, when updating the vmalloc
* mappings we don't have to walk all processes pgdirs and
* add the high mappings all at once. Instead we do it as they
* are used. However vmalloc'ed page entries have the PAGE_GLOBAL
* bit set so sometimes the TLB can use a lingering entry.
*
* This verifies that the fault happens in kernel space
* and that the fault was not a protection error (error_code & 1).
*/
if (address >= VMALLOC_START &&
!protection &&
!user_mode(regs))
goto vmalloc_fault;
/* we can and should enable interrupts at this point */
sti();
mm = tsk->mm;
info.si_code = SEGV_MAPERR;
/*
* If we're in an interrupt or have no user
* context, we must not take the fault..
*/
if (in_interrupt() || !mm)
goto no_context;
down_read(&mm->mmap_sem);
vma = find_vma(mm, address);
if (!vma)
goto bad_area;
if (vma->vm_start <= address)
goto good_area;
if (!(vma->vm_flags & VM_GROWSDOWN))
goto bad_area;
if (user_mode(regs)) {
/*
* accessing the stack below usp is always a bug.
* we get page-aligned addresses so we can only check
* if we're within a page from usp, but that might be
* enough to catch brutal errors at least.
*/
if (address + PAGE_SIZE < rdusp())
goto bad_area;
}
if (expand_stack(vma, address))
goto bad_area;
/*
* Ok, we have a good vm_area for this memory access, so
* we can handle it..
*/
good_area:
info.si_code = SEGV_ACCERR;
/* first do some preliminary protection checks */
if (writeaccess) {
if (!(vma->vm_flags & VM_WRITE))
goto bad_area;
} else {
if (!(vma->vm_flags & (VM_READ | VM_EXEC)))
goto bad_area;
}
/*
* If for any reason at all we couldn't handle the fault,
* make sure we exit gracefully rather than endlessly redo
* the fault.
*/
switch (handle_mm_fault(mm, vma, address, writeaccess)) {
case 1:
tsk->min_flt++;
break;
case 2:
tsk->maj_flt++;
break;
case 0:
goto do_sigbus;
default:
goto out_of_memory;
}
up_read(&mm->mmap_sem);
return;
/*
* Something tried to access memory that isn't in our memory map..
* Fix it, but check if it's kernel or user first..
*/
bad_area:
up_read(&mm->mmap_sem);
bad_area_nosemaphore:
DPG(show_registers(regs));
/* User mode accesses just cause a SIGSEGV */
if (user_mode(regs)) {
info.si_signo = SIGSEGV;
info.si_errno = 0;
/* info.si_code has been set above */
info.si_addr = (void *)address;
force_sig_info(SIGSEGV, &info, tsk);
return;
}
no_context:
/* Are we prepared to handle this kernel fault?
*
* (The kernel has valid exception-points in the source
* when it acesses user-memory. When it fails in one
* of those points, we find it in a table and do a jump
* to some fixup code that loads an appropriate error
* code)
*/
if (find_fixup_code(regs))
return;
/*
* Oops. The kernel tried to access some bad page. We'll have to
* terminate things with extreme prejudice.
*/
if ((unsigned long) (address) < PAGE_SIZE)
printk(KERN_ALERT "Unable to handle kernel NULL pointer dereference");
else
printk(KERN_ALERT "Unable to handle kernel access");
printk(" at virtual address %08lx\n",address);
die_if_kernel("Oops", regs, (writeaccess << 1) | protection);
do_exit(SIGKILL);
/*
* We ran out of memory, or some other thing happened to us that made
* us unable to handle the page fault gracefully.
*/
out_of_memory:
up_read(&mm->mmap_sem);
printk("VM: killing process %s\n", tsk->comm);
if (user_mode(regs))
do_exit(SIGKILL);
goto no_context;
do_sigbus:
up_read(&mm->mmap_sem);
/*
* Send a sigbus, regardless of whether we were in kernel
* or user mode.
*/
info.si_signo = SIGBUS;
info.si_errno = 0;
info.si_code = BUS_ADRERR;
info.si_addr = (void *)address;
force_sig_info(SIGBUS, &info, tsk);
/* Kernel mode? Handle exceptions or die */
if (!user_mode(regs))
goto no_context;
return;
vmalloc_fault:
{
/*
* Synchronize this task's top level page-table
* with the 'reference' page table.
*
* Use current_pgd instead of tsk->active_mm->pgd
* since the latter might be unavailable if this
* code is executed in a misfortunately run irq
* (like inside schedule() between switch_mm and
* switch_to...).
*/
int offset = pgd_index(address);
pgd_t *pgd, *pgd_k;
pmd_t *pmd, *pmd_k;
pte_t *pte_k;
pgd = (pgd_t *)current_pgd + offset;
pgd_k = init_mm.pgd + offset;
/* Since we're two-level, we don't need to do both
* set_pgd and set_pmd (they do the same thing). If
* we go three-level at some point, do the right thing
* with pgd_present and set_pgd here.
*
* Also, since the vmalloc area is global, we don't
* need to copy individual PTE's, it is enough to
* copy the pgd pointer into the pte page of the
* root task. If that is there, we'll find our pte if
* it exists.
*/
pmd = pmd_offset(pgd, address);
pmd_k = pmd_offset(pgd_k, address);
if (!pmd_present(*pmd_k))
goto bad_area_nosemaphore;
set_pmd(pmd, *pmd_k);
/* Make sure the actual PTE exists as well to
* catch kernel vmalloc-area accesses to non-mapped
* addresses. If we don't do this, this will just
* silently loop forever.
*/
pte_k = pte_offset_kernel(pmd_k, address);
if (!pte_present(*pte_k))
goto no_context;
return;
}
}

225
arch/cris/mm/init.c Normal file
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/*
* linux/arch/cris/mm/init.c
*
* Copyright (C) 1995 Linus Torvalds
* Copyright (C) 2000,2001 Axis Communications AB
*
* Authors: Bjorn Wesen (bjornw@axis.com)
*
* $Log: init.c,v $
* Revision 1.11 2004/05/28 09:28:56 starvik
* Calculation of loops_per_usec moved because initalization order has changed
* in Linux 2.6.
*
* Revision 1.10 2004/05/14 07:58:05 starvik
* Merge of changes from 2.4
*
* Revision 1.9 2003/07/04 08:27:54 starvik
* Merge of Linux 2.5.74
*
* Revision 1.8 2003/04/09 05:20:48 starvik
* Merge of Linux 2.5.67
*
* Revision 1.7 2003/01/22 06:48:38 starvik
* Fixed warnings issued by GCC 3.2.1
*
* Revision 1.6 2002/12/11 14:44:48 starvik
* Extracted v10 (ETRAX 100LX) specific stuff to arch/cris/arch-v10/mm
*
* Revision 1.5 2002/11/18 07:37:37 starvik
* Added cache bug workaround (from Linux 2.4)
*
* Revision 1.4 2002/11/13 15:40:24 starvik
* Removed the page table cache stuff (as done in other archs)
*
* Revision 1.3 2002/11/05 06:45:13 starvik
* Merge of Linux 2.5.45
*
* Revision 1.2 2001/12/18 13:35:22 bjornw
* Applied the 2.4.13->2.4.16 CRIS patch to 2.5.1 (is a copy of 2.4.15).
*
* Revision 1.31 2001/11/13 16:22:00 bjornw
* Skip calculating totalram and sharedram in si_meminfo
*
* Revision 1.30 2001/11/12 19:02:10 pkj
* Fixed compiler warnings.
*
* Revision 1.29 2001/07/25 16:09:50 bjornw
* val->sharedram will stay 0
*
* Revision 1.28 2001/06/28 16:30:17 bjornw
* Oops. This needs to wait until 2.4.6 is merged
*
* Revision 1.27 2001/06/28 14:04:07 bjornw
* Fill in sharedram
*
* Revision 1.26 2001/06/18 06:36:02 hp
* Enable free_initmem of __init-type pages
*
* Revision 1.25 2001/06/13 00:02:23 bjornw
* Use a separate variable to store the current pgd to avoid races in schedule
*
* Revision 1.24 2001/05/15 00:52:20 hp
* Only map segment 0xa as seg if CONFIG_JULIETTE
*
* Revision 1.23 2001/04/04 14:35:40 bjornw
* * Removed get_pte_slow and friends (2.4.3 change)
* * Removed bad_pmd handling (2.4.3 change)
*
* Revision 1.22 2001/04/04 13:38:04 matsfg
* Moved ioremap to a separate function instead
*
* Revision 1.21 2001/03/27 09:28:33 bjornw
* ioremap used too early - lets try it in mem_init instead
*
* Revision 1.20 2001/03/23 07:39:21 starvik
* Corrected according to review remarks
*
* Revision 1.19 2001/03/15 14:25:17 bjornw
* More general shadow registers and ioremaped addresses for external I/O
*
* Revision 1.18 2001/02/23 12:46:44 bjornw
* * 0xc was not CSE1; 0x8 is, same as uncached flash, so we move the uncached
* flash during CRIS_LOW_MAP from 0xe to 0x8 so both the flash and the I/O
* is mapped straight over (for !CRIS_LOW_MAP the uncached flash is still 0xe)
*
* Revision 1.17 2001/02/22 15:05:21 bjornw
* Map 0x9 straight over during LOW_MAP to allow for memory mapped LEDs
*
* Revision 1.16 2001/02/22 15:02:35 bjornw
* Map 0xc straight over during LOW_MAP to allow for memory mapped I/O
*
* Revision 1.15 2001/01/10 21:12:10 bjornw
* loops_per_sec -> loops_per_jiffy
*
* Revision 1.14 2000/11/22 16:23:20 bjornw
* Initialize totalhigh counters to 0 to make /proc/meminfo look nice.
*
* Revision 1.13 2000/11/21 16:37:51 bjornw
* Temporarily disable initmem freeing
*
* Revision 1.12 2000/11/21 13:55:07 bjornw
* Use CONFIG_CRIS_LOW_MAP for the low VM map instead of explicit CPU type
*
* Revision 1.11 2000/10/06 12:38:22 bjornw
* Cast empty_bad_page correctly (should really be of * type from the start..
*
* Revision 1.10 2000/10/04 16:53:57 bjornw
* Fix memory-map due to LX features
*
* Revision 1.9 2000/09/13 15:47:49 bjornw
* Wrong count in reserved-pages loop
*
* Revision 1.8 2000/09/13 14:35:10 bjornw
* 2.4.0-test8 added a new arg to free_area_init_node
*
* Revision 1.7 2000/08/17 15:35:55 bjornw
* 2.4.0-test6 removed MAP_NR and inserted virt_to_page
*
*
*/
#include <linux/init.h>
#include <linux/bootmem.h>
#include <asm/tlb.h>
DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
unsigned long empty_zero_page;
extern char _stext, _edata, _etext; /* From linkerscript */
extern char __init_begin, __init_end;
void
show_mem(void)
{
int i,free = 0,total = 0,cached = 0, reserved = 0, nonshared = 0;
int shared = 0;
printk("\nMem-info:\n");
show_free_areas();
printk("Free swap: %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10));
i = max_mapnr;
while (i-- > 0) {
total++;
if (PageReserved(mem_map+i))
reserved++;
else if (PageSwapCache(mem_map+i))
cached++;
else if (!page_count(mem_map+i))
free++;
else if (page_count(mem_map+i) == 1)
nonshared++;
else
shared += page_count(mem_map+i) - 1;
}
printk("%d pages of RAM\n",total);
printk("%d free pages\n",free);
printk("%d reserved pages\n",reserved);
printk("%d pages nonshared\n",nonshared);
printk("%d pages shared\n",shared);
printk("%d pages swap cached\n",cached);
}
void __init
mem_init(void)
{
int codesize, reservedpages, datasize, initsize;
unsigned long tmp;
if(!mem_map)
BUG();
/* max/min_low_pfn was set by setup.c
* now we just copy it to some other necessary places...
*
* high_memory was also set in setup.c
*/
max_mapnr = num_physpages = max_low_pfn - min_low_pfn;
/* this will put all memory onto the freelists */
totalram_pages = free_all_bootmem();
reservedpages = 0;
for (tmp = 0; tmp < max_mapnr; tmp++) {
/*
* Only count reserved RAM pages
*/
if (PageReserved(mem_map + tmp))
reservedpages++;
}
codesize = (unsigned long) &_etext - (unsigned long) &_stext;
datasize = (unsigned long) &_edata - (unsigned long) &_etext;
initsize = (unsigned long) &__init_end - (unsigned long) &__init_begin;
printk(KERN_INFO
"Memory: %luk/%luk available (%dk kernel code, %dk reserved, %dk data, "
"%dk init)\n" ,
(unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
max_mapnr << (PAGE_SHIFT-10),
codesize >> 10,
reservedpages << (PAGE_SHIFT-10),
datasize >> 10,
initsize >> 10
);
}
/* free the pages occupied by initialization code */
void
free_initmem(void)
{
unsigned long addr;
addr = (unsigned long)(&__init_begin);
for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) {
ClearPageReserved(virt_to_page(addr));
set_page_count(virt_to_page(addr), 1);
free_page(addr);
totalram_pages++;
}
printk (KERN_INFO "Freeing unused kernel memory: %luk freed\n",
(unsigned long)((&__init_end - &__init_begin) >> 10));
}

146
arch/cris/mm/ioremap.c Normal file
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/*
* arch/cris/mm/ioremap.c
*
* Re-map IO memory to kernel address space so that we can access it.
* Needed for memory-mapped I/O devices mapped outside our normal DRAM
* window (that is, all memory-mapped I/O devices).
*
* (C) Copyright 1995 1996 Linus Torvalds
* CRIS-port by Axis Communications AB
*/
#include <linux/vmalloc.h>
#include <asm/io.h>
#include <asm/pgalloc.h>
#include <asm/cacheflush.h>
#include <asm/tlbflush.h>
extern inline void remap_area_pte(pte_t * pte, unsigned long address, unsigned long size,
unsigned long phys_addr, unsigned long flags)
{
unsigned long end;
address &= ~PMD_MASK;
end = address + size;
if (end > PMD_SIZE)
end = PMD_SIZE;
if (address >= end)
BUG();
do {
if (!pte_none(*pte)) {
printk("remap_area_pte: page already exists\n");
BUG();
}
set_pte(pte, mk_pte_phys(phys_addr, __pgprot(_PAGE_PRESENT | __READABLE |
__WRITEABLE | _PAGE_GLOBAL |
_PAGE_KERNEL | flags)));
address += PAGE_SIZE;
phys_addr += PAGE_SIZE;
pte++;
} while (address && (address < end));
}
static inline int remap_area_pmd(pmd_t * pmd, unsigned long address, unsigned long size,
unsigned long phys_addr, unsigned long flags)
{
unsigned long end;
address &= ~PGDIR_MASK;
end = address + size;
if (end > PGDIR_SIZE)
end = PGDIR_SIZE;
phys_addr -= address;
if (address >= end)
BUG();
do {
pte_t * pte = pte_alloc_kernel(&init_mm, pmd, address);
if (!pte)
return -ENOMEM;
remap_area_pte(pte, address, end - address, address + phys_addr, flags);
address = (address + PMD_SIZE) & PMD_MASK;
pmd++;
} while (address && (address < end));
return 0;
}
static int remap_area_pages(unsigned long address, unsigned long phys_addr,
unsigned long size, unsigned long flags)
{
int error;
pgd_t * dir;
unsigned long end = address + size;
phys_addr -= address;
dir = pgd_offset(&init_mm, address);
flush_cache_all();
if (address >= end)
BUG();
spin_lock(&init_mm.page_table_lock);
do {
pmd_t *pmd;
pmd = pmd_alloc(&init_mm, dir, address);
error = -ENOMEM;
if (!pmd)
break;
if (remap_area_pmd(pmd, address, end - address,
phys_addr + address, flags))
break;
error = 0;
address = (address + PGDIR_SIZE) & PGDIR_MASK;
dir++;
} while (address && (address < end));
spin_unlock(&init_mm.page_table_lock);
flush_tlb_all();
return error;
}
/*
* Generic mapping function (not visible outside):
*/
/*
* Remap an arbitrary physical address space into the kernel virtual
* address space. Needed when the kernel wants to access high addresses
* directly.
*
* NOTE! We need to allow non-page-aligned mappings too: we will obviously
* have to convert them into an offset in a page-aligned mapping, but the
* caller shouldn't need to know that small detail.
*/
void * __ioremap(unsigned long phys_addr, unsigned long size, unsigned long flags)
{
void * addr;
struct vm_struct * area;
unsigned long offset, last_addr;
/* Don't allow wraparound or zero size */
last_addr = phys_addr + size - 1;
if (!size || last_addr < phys_addr)
return NULL;
/*
* Mappings have to be page-aligned
*/
offset = phys_addr & ~PAGE_MASK;
phys_addr &= PAGE_MASK;
size = PAGE_ALIGN(last_addr+1) - phys_addr;
/*
* Ok, go for it..
*/
area = get_vm_area(size, VM_IOREMAP);
if (!area)
return NULL;
addr = area->addr;
if (remap_area_pages((unsigned long) addr, phys_addr, size, flags)) {
vfree(addr);
return NULL;
}
return (void *) (offset + (char *)addr);
}
void iounmap(void *addr)
{
if (addr > high_memory)
return vfree((void *) (PAGE_MASK & (unsigned long) addr));
}

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arch/cris/mm/tlb.c Normal file
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/*
* linux/arch/cris/mm/tlb.c
*
* Copyright (C) 2000, 2001 Axis Communications AB
*
* Authors: Bjorn Wesen (bjornw@axis.com)
*
*/
#include <linux/init.h>
#include <asm/tlb.h>
#define D(x)
/* The TLB can host up to 64 different mm contexts at the same time.
* The running context is R_MMU_CONTEXT, and each TLB entry contains a
* page_id that has to match to give a hit. In page_id_map, we keep track
* of which mm's we have assigned which page_id's, so that we know when
* to invalidate TLB entries.
*
* The last page_id is never running - it is used as an invalid page_id
* so we can make TLB entries that will never match.
*
* Notice that we need to make the flushes atomic, otherwise an interrupt
* handler that uses vmalloced memory might cause a TLB load in the middle
* of a flush causing.
*/
struct mm_struct *page_id_map[NUM_PAGEID];
static int map_replace_ptr = 1; /* which page_id_map entry to replace next */
/*
* Initialize the context related info for a new mm_struct
* instance.
*/
int
init_new_context(struct task_struct *tsk, struct mm_struct *mm)
{
mm->context = NO_CONTEXT;
return 0;
}
/* the following functions are similar to those used in the PPC port */
static inline void
alloc_context(struct mm_struct *mm)
{
struct mm_struct *old_mm;
D(printk("tlb: alloc context %d (%p)\n", map_replace_ptr, mm));
/* did we replace an mm ? */
old_mm = page_id_map[map_replace_ptr];
if(old_mm) {
/* throw out any TLB entries belonging to the mm we replace
* in the map
*/
flush_tlb_mm(old_mm);
old_mm->context = NO_CONTEXT;
}
/* insert it into the page_id_map */
mm->context = map_replace_ptr;
page_id_map[map_replace_ptr] = mm;
map_replace_ptr++;
if(map_replace_ptr == INVALID_PAGEID)
map_replace_ptr = 0; /* wrap around */
}
/*
* if needed, get a new MMU context for the mm. otherwise nothing is done.
*/
void
get_mmu_context(struct mm_struct *mm)
{
if(mm->context == NO_CONTEXT)
alloc_context(mm);
}
/* called by __exit_mm to destroy the used MMU context if any before
* destroying the mm itself. this is only called when the last user of the mm
* drops it.
*
* the only thing we really need to do here is mark the used PID slot
* as empty.
*/
void
destroy_context(struct mm_struct *mm)
{
if(mm->context != NO_CONTEXT) {
D(printk("destroy_context %d (%p)\n", mm->context, mm));
flush_tlb_mm(mm); /* TODO this might be redundant ? */
page_id_map[mm->context] = NULL;
/* mm->context = NO_CONTEXT; redundant.. mm will be freed */
}
}
/* called once during VM initialization, from init.c */
void __init
tlb_init(void)
{
int i;
/* clear the page_id map */
for (i = 1; i < sizeof (page_id_map) / sizeof (page_id_map[0]); i++)
page_id_map[i] = NULL;
/* invalidate the entire TLB */
flush_tlb_all();
/* the init_mm has context 0 from the boot */
page_id_map[0] = &init_mm;
}