diff options
Diffstat (limited to 'ANDROID_3.4.5/arch/m68k/sun3/mmu_emu.c')
| -rw-r--r-- | ANDROID_3.4.5/arch/m68k/sun3/mmu_emu.c | 425 |
1 files changed, 0 insertions, 425 deletions
diff --git a/ANDROID_3.4.5/arch/m68k/sun3/mmu_emu.c b/ANDROID_3.4.5/arch/m68k/sun3/mmu_emu.c deleted file mode 100644 index 8edc510a..00000000 --- a/ANDROID_3.4.5/arch/m68k/sun3/mmu_emu.c +++ /dev/null @@ -1,425 +0,0 @@ -/* -** Tablewalk MMU emulator -** -** by Toshiyasu Morita -** -** Started 1/16/98 @ 2:22 am -*/ - -#include <linux/mman.h> -#include <linux/mm.h> -#include <linux/kernel.h> -#include <linux/ptrace.h> -#include <linux/delay.h> -#include <linux/bootmem.h> -#include <linux/bitops.h> -#include <linux/module.h> - -#include <asm/setup.h> -#include <asm/traps.h> -#include <asm/uaccess.h> -#include <asm/page.h> -#include <asm/pgtable.h> -#include <asm/sun3mmu.h> -#include <asm/segment.h> -#include <asm/oplib.h> -#include <asm/mmu_context.h> -#include <asm/dvma.h> - - -#undef DEBUG_MMU_EMU -#define DEBUG_PROM_MAPS - -/* -** Defines -*/ - -#define CONTEXTS_NUM 8 -#define SEGMAPS_PER_CONTEXT_NUM 2048 -#define PAGES_PER_SEGMENT 16 -#define PMEGS_NUM 256 -#define PMEG_MASK 0xFF - -/* -** Globals -*/ - -unsigned long m68k_vmalloc_end; -EXPORT_SYMBOL(m68k_vmalloc_end); - -unsigned long pmeg_vaddr[PMEGS_NUM]; -unsigned char pmeg_alloc[PMEGS_NUM]; -unsigned char pmeg_ctx[PMEGS_NUM]; - -/* pointers to the mm structs for each task in each - context. 0xffffffff is a marker for kernel context */ -static struct mm_struct *ctx_alloc[CONTEXTS_NUM] = { - [0] = (struct mm_struct *)0xffffffff -}; - -/* has this context been mmdrop'd? */ -static unsigned char ctx_avail = CONTEXTS_NUM-1; - -/* array of pages to be marked off for the rom when we do mem_init later */ -/* 256 pages lets the rom take up to 2mb of physical ram.. I really - hope it never wants mote than that. */ -unsigned long rom_pages[256]; - -/* Print a PTE value in symbolic form. For debugging. */ -void print_pte (pte_t pte) -{ -#if 0 - /* Verbose version. */ - unsigned long val = pte_val (pte); - printk (" pte=%lx [addr=%lx", - val, (val & SUN3_PAGE_PGNUM_MASK) << PAGE_SHIFT); - if (val & SUN3_PAGE_VALID) printk (" valid"); - if (val & SUN3_PAGE_WRITEABLE) printk (" write"); - if (val & SUN3_PAGE_SYSTEM) printk (" sys"); - if (val & SUN3_PAGE_NOCACHE) printk (" nocache"); - if (val & SUN3_PAGE_ACCESSED) printk (" accessed"); - if (val & SUN3_PAGE_MODIFIED) printk (" modified"); - switch (val & SUN3_PAGE_TYPE_MASK) { - case SUN3_PAGE_TYPE_MEMORY: printk (" memory"); break; - case SUN3_PAGE_TYPE_IO: printk (" io"); break; - case SUN3_PAGE_TYPE_VME16: printk (" vme16"); break; - case SUN3_PAGE_TYPE_VME32: printk (" vme32"); break; - } - printk ("]\n"); -#else - /* Terse version. More likely to fit on a line. */ - unsigned long val = pte_val (pte); - char flags[7], *type; - - flags[0] = (val & SUN3_PAGE_VALID) ? 'v' : '-'; - flags[1] = (val & SUN3_PAGE_WRITEABLE) ? 'w' : '-'; - flags[2] = (val & SUN3_PAGE_SYSTEM) ? 's' : '-'; - flags[3] = (val & SUN3_PAGE_NOCACHE) ? 'x' : '-'; - flags[4] = (val & SUN3_PAGE_ACCESSED) ? 'a' : '-'; - flags[5] = (val & SUN3_PAGE_MODIFIED) ? 'm' : '-'; - flags[6] = '\0'; - - switch (val & SUN3_PAGE_TYPE_MASK) { - case SUN3_PAGE_TYPE_MEMORY: type = "memory"; break; - case SUN3_PAGE_TYPE_IO: type = "io" ; break; - case SUN3_PAGE_TYPE_VME16: type = "vme16" ; break; - case SUN3_PAGE_TYPE_VME32: type = "vme32" ; break; - default: type = "unknown?"; break; - } - - printk (" pte=%08lx [%07lx %s %s]\n", - val, (val & SUN3_PAGE_PGNUM_MASK) << PAGE_SHIFT, flags, type); -#endif -} - -/* Print the PTE value for a given virtual address. For debugging. */ -void print_pte_vaddr (unsigned long vaddr) -{ - printk (" vaddr=%lx [%02lx]", vaddr, sun3_get_segmap (vaddr)); - print_pte (__pte (sun3_get_pte (vaddr))); -} - -/* - * Initialise the MMU emulator. - */ -void mmu_emu_init(unsigned long bootmem_end) -{ - unsigned long seg, num; - int i,j; - - memset(rom_pages, 0, sizeof(rom_pages)); - memset(pmeg_vaddr, 0, sizeof(pmeg_vaddr)); - memset(pmeg_alloc, 0, sizeof(pmeg_alloc)); - memset(pmeg_ctx, 0, sizeof(pmeg_ctx)); - - /* pmeg align the end of bootmem, adding another pmeg, - * later bootmem allocations will likely need it */ - bootmem_end = (bootmem_end + (2 * SUN3_PMEG_SIZE)) & ~SUN3_PMEG_MASK; - - /* mark all of the pmegs used thus far as reserved */ - for (i=0; i < __pa(bootmem_end) / SUN3_PMEG_SIZE ; ++i) - pmeg_alloc[i] = 2; - - - /* I'm thinking that most of the top pmeg's are going to be - used for something, and we probably shouldn't risk it */ - for(num = 0xf0; num <= 0xff; num++) - pmeg_alloc[num] = 2; - - /* liberate all existing mappings in the rest of kernel space */ - for(seg = bootmem_end; seg < 0x0f800000; seg += SUN3_PMEG_SIZE) { - i = sun3_get_segmap(seg); - - if(!pmeg_alloc[i]) { -#ifdef DEBUG_MMU_EMU - printk("freed: "); - print_pte_vaddr (seg); -#endif - sun3_put_segmap(seg, SUN3_INVALID_PMEG); - } - } - - j = 0; - for (num=0, seg=0x0F800000; seg<0x10000000; seg+=16*PAGE_SIZE) { - if (sun3_get_segmap (seg) != SUN3_INVALID_PMEG) { -#ifdef DEBUG_PROM_MAPS - for(i = 0; i < 16; i++) { - printk ("mapped:"); - print_pte_vaddr (seg + (i*PAGE_SIZE)); - break; - } -#endif - // the lowest mapping here is the end of our - // vmalloc region - if (!m68k_vmalloc_end) - m68k_vmalloc_end = seg; - - // mark the segmap alloc'd, and reserve any - // of the first 0xbff pages the hardware is - // already using... does any sun3 support > 24mb? - pmeg_alloc[sun3_get_segmap(seg)] = 2; - } - } - - dvma_init(); - - - /* blank everything below the kernel, and we've got the base - mapping to start all the contexts off with... */ - for(seg = 0; seg < PAGE_OFFSET; seg += SUN3_PMEG_SIZE) - sun3_put_segmap(seg, SUN3_INVALID_PMEG); - - set_fs(MAKE_MM_SEG(3)); - for(seg = 0; seg < 0x10000000; seg += SUN3_PMEG_SIZE) { - i = sun3_get_segmap(seg); - for(j = 1; j < CONTEXTS_NUM; j++) - (*(romvec->pv_setctxt))(j, (void *)seg, i); - } - set_fs(KERNEL_DS); - -} - -/* erase the mappings for a dead context. Uses the pg_dir for hints - as the pmeg tables proved somewhat unreliable, and unmapping all of - TASK_SIZE was much slower and no more stable. */ -/* todo: find a better way to keep track of the pmegs used by a - context for when they're cleared */ -void clear_context(unsigned long context) -{ - unsigned char oldctx; - unsigned long i; - - if(context) { - if(!ctx_alloc[context]) - panic("clear_context: context not allocated\n"); - - ctx_alloc[context]->context = SUN3_INVALID_CONTEXT; - ctx_alloc[context] = (struct mm_struct *)0; - ctx_avail++; - } - - oldctx = sun3_get_context(); - - sun3_put_context(context); - - for(i = 0; i < SUN3_INVALID_PMEG; i++) { - if((pmeg_ctx[i] == context) && (pmeg_alloc[i] == 1)) { - sun3_put_segmap(pmeg_vaddr[i], SUN3_INVALID_PMEG); - pmeg_ctx[i] = 0; - pmeg_alloc[i] = 0; - pmeg_vaddr[i] = 0; - } - } - - sun3_put_context(oldctx); -} - -/* gets an empty context. if full, kills the next context listed to - die first */ -/* This context invalidation scheme is, well, totally arbitrary, I'm - sure it could be much more intelligent... but it gets the job done - for now without much overhead in making it's decision. */ -/* todo: come up with optimized scheme for flushing contexts */ -unsigned long get_free_context(struct mm_struct *mm) -{ - unsigned long new = 1; - static unsigned char next_to_die = 1; - - if(!ctx_avail) { - /* kill someone to get our context */ - new = next_to_die; - clear_context(new); - next_to_die = (next_to_die + 1) & 0x7; - if(!next_to_die) - next_to_die++; - } else { - while(new < CONTEXTS_NUM) { - if(ctx_alloc[new]) - new++; - else - break; - } - // check to make sure one was really free... - if(new == CONTEXTS_NUM) - panic("get_free_context: failed to find free context"); - } - - ctx_alloc[new] = mm; - ctx_avail--; - - return new; -} - -/* - * Dynamically select a `spare' PMEG and use it to map virtual `vaddr' in - * `context'. Maintain internal PMEG management structures. This doesn't - * actually map the physical address, but does clear the old mappings. - */ -//todo: better allocation scheme? but is extra complexity worthwhile? -//todo: only clear old entries if necessary? how to tell? - -inline void mmu_emu_map_pmeg (int context, int vaddr) -{ - static unsigned char curr_pmeg = 128; - int i; - - /* Round address to PMEG boundary. */ - vaddr &= ~SUN3_PMEG_MASK; - - /* Find a spare one. */ - while (pmeg_alloc[curr_pmeg] == 2) - ++curr_pmeg; - - -#ifdef DEBUG_MMU_EMU -printk("mmu_emu_map_pmeg: pmeg %x to context %d vaddr %x\n", - curr_pmeg, context, vaddr); -#endif - - /* Invalidate old mapping for the pmeg, if any */ - if (pmeg_alloc[curr_pmeg] == 1) { - sun3_put_context(pmeg_ctx[curr_pmeg]); - sun3_put_segmap (pmeg_vaddr[curr_pmeg], SUN3_INVALID_PMEG); - sun3_put_context(context); - } - - /* Update PMEG management structures. */ - // don't take pmeg's away from the kernel... - if(vaddr >= PAGE_OFFSET) { - /* map kernel pmegs into all contexts */ - unsigned char i; - - for(i = 0; i < CONTEXTS_NUM; i++) { - sun3_put_context(i); - sun3_put_segmap (vaddr, curr_pmeg); - } - sun3_put_context(context); - pmeg_alloc[curr_pmeg] = 2; - pmeg_ctx[curr_pmeg] = 0; - - } - else { - pmeg_alloc[curr_pmeg] = 1; - pmeg_ctx[curr_pmeg] = context; - sun3_put_segmap (vaddr, curr_pmeg); - - } - pmeg_vaddr[curr_pmeg] = vaddr; - - /* Set hardware mapping and clear the old PTE entries. */ - for (i=0; i<SUN3_PMEG_SIZE; i+=SUN3_PTE_SIZE) - sun3_put_pte (vaddr + i, SUN3_PAGE_SYSTEM); - - /* Consider a different one next time. */ - ++curr_pmeg; -} - -/* - * Handle a pagefault at virtual address `vaddr'; check if there should be a - * page there (specifically, whether the software pagetables indicate that - * there is). This is necessary due to the limited size of the second-level - * Sun3 hardware pagetables (256 groups of 16 pages). If there should be a - * mapping present, we select a `spare' PMEG and use it to create a mapping. - * `read_flag' is nonzero for a read fault; zero for a write. Returns nonzero - * if we successfully handled the fault. - */ -//todo: should we bump minor pagefault counter? if so, here or in caller? -//todo: possibly inline this into bus_error030 in <asm/buserror.h> ? - -// kernel_fault is set when a kernel page couldn't be demand mapped, -// and forces another try using the kernel page table. basically a -// hack so that vmalloc would work correctly. - -int mmu_emu_handle_fault (unsigned long vaddr, int read_flag, int kernel_fault) -{ - unsigned long segment, offset; - unsigned char context; - pte_t *pte; - pgd_t * crp; - - if(current->mm == NULL) { - crp = swapper_pg_dir; - context = 0; - } else { - context = current->mm->context; - if(kernel_fault) - crp = swapper_pg_dir; - else - crp = current->mm->pgd; - } - -#ifdef DEBUG_MMU_EMU - printk ("mmu_emu_handle_fault: vaddr=%lx type=%s crp=%p\n", - vaddr, read_flag ? "read" : "write", crp); -#endif - - segment = (vaddr >> SUN3_PMEG_SIZE_BITS) & 0x7FF; - offset = (vaddr >> SUN3_PTE_SIZE_BITS) & 0xF; - -#ifdef DEBUG_MMU_EMU - printk ("mmu_emu_handle_fault: segment=%lx offset=%lx\n", segment, offset); -#endif - - pte = (pte_t *) pgd_val (*(crp + segment)); - -//todo: next line should check for valid pmd properly. - if (!pte) { -// printk ("mmu_emu_handle_fault: invalid pmd\n"); - return 0; - } - - pte = (pte_t *) __va ((unsigned long)(pte + offset)); - - /* Make sure this is a valid page */ - if (!(pte_val (*pte) & SUN3_PAGE_VALID)) - return 0; - - /* Make sure there's a pmeg allocated for the page */ - if (sun3_get_segmap (vaddr&~SUN3_PMEG_MASK) == SUN3_INVALID_PMEG) - mmu_emu_map_pmeg (context, vaddr); - - /* Write the pte value to hardware MMU */ - sun3_put_pte (vaddr&PAGE_MASK, pte_val (*pte)); - - /* Update software copy of the pte value */ -// I'm not sure this is necessary. If this is required, we ought to simply -// copy this out when we reuse the PMEG or at some other convenient time. -// Doing it here is fairly meaningless, anyway, as we only know about the -// first access to a given page. --m - if (!read_flag) { - if (pte_val (*pte) & SUN3_PAGE_WRITEABLE) - pte_val (*pte) |= (SUN3_PAGE_ACCESSED - | SUN3_PAGE_MODIFIED); - else - return 0; /* Write-protect error. */ - } else - pte_val (*pte) |= SUN3_PAGE_ACCESSED; - -#ifdef DEBUG_MMU_EMU - printk ("seg:%d crp:%p ->", get_fs().seg, crp); - print_pte_vaddr (vaddr); - printk ("\n"); -#endif - - return 1; -} |