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[/] [or1k/] [trunk/] [uclinux/] [uClinux-2.0.x/] [arch/] [sparc/] [mm/] [sun4c.c] - Blame information for rev 1765

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/* sun4c.c: Doing in software what should be done in hardware.
 *
 * Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu)
 */
 
#include <linux/kernel.h>
#include <linux/mm.h>
 
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/vaddrs.h>
#include <asm/idprom.h>
#include <asm/machines.h>
#include <asm/memreg.h>
#include <asm/processor.h>
 
extern int num_segmaps, num_contexts;
 
/* Flushing the cache. */
struct sun4c_vac_props sun4c_vacinfo;
static int ctxflushes, segflushes, pageflushes;
 
/* convert a virtual address to a physical address and vice
   versa. Easy on the 4c */
static unsigned long sun4c_v2p(unsigned long vaddr)
{
  return(vaddr - PAGE_OFFSET);
}
 
static unsigned long sun4c_p2v(unsigned long vaddr)
{
  return(vaddr + PAGE_OFFSET);
}
 
 
/* Invalidate every sun4c cache line tag. */
void sun4c_flush_all(void)
{
        unsigned long begin, end;
 
        if(sun4c_vacinfo.on)
                panic("SUN4C: AIEEE, trying to invalidate vac while"
                      " it is on.");
 
        /* Clear 'valid' bit in all cache line tags */
        begin = AC_CACHETAGS;
        end = (AC_CACHETAGS + sun4c_vacinfo.num_bytes);
        while(begin < end) {
                __asm__ __volatile__("sta %%g0, [%0] %1\n\t" : :
                                     "r" (begin), "i" (ASI_CONTROL));
                begin += sun4c_vacinfo.linesize;
        }
}
 
/* Blow the entire current context out of the virtual cache. */
static inline void sun4c_flush_context(void)
{
        unsigned long vaddr;
 
        ctxflushes++;
        if(sun4c_vacinfo.do_hwflushes) {
                for(vaddr=0; vaddr < sun4c_vacinfo.num_bytes; vaddr+=PAGE_SIZE)
                        __asm__ __volatile__("sta %%g0, [%0] %1\n\t" : :
                                             "r" (vaddr), "i" (ASI_HWFLUSHCONTEXT));
        } else {
                int incr = sun4c_vacinfo.linesize;
                for(vaddr=0; vaddr < sun4c_vacinfo.num_bytes; vaddr+=incr)
                        __asm__ __volatile__("sta %%g0, [%0] %1\n\t" : :
                                             "r" (vaddr), "i" (ASI_FLUSHCTX));
        }
}
 
/* Scrape the segment starting at ADDR from the virtual cache. */
static inline void sun4c_flush_segment(unsigned long addr)
{
        unsigned long end;
 
        segflushes++;
        addr &= SUN4C_REAL_PGDIR_MASK;
        end = (addr + sun4c_vacinfo.num_bytes);
        if(sun4c_vacinfo.do_hwflushes) {
                for( ; addr < end; addr += PAGE_SIZE)
                        __asm__ __volatile__("sta %%g0, [%0] %1\n\t" : :
                                             "r" (addr), "i" (ASI_HWFLUSHSEG));
        } else {
                int incr = sun4c_vacinfo.linesize;
                for( ; addr < end; addr += incr)
                        __asm__ __volatile__("sta %%g0, [%0] %1\n\t" : :
                                             "r" (addr), "i" (ASI_FLUSHSEG));
        }
}
 
/* Bolix one page from the virtual cache. */
static inline void sun4c_flush_page(unsigned long addr)
{
        addr &= PAGE_MASK;
 
        pageflushes++;
        if(sun4c_vacinfo.do_hwflushes) {
                __asm__ __volatile__("sta %%g0, [%0] %1\n\t" : :
                                     "r" (addr), "i" (ASI_HWFLUSHPAGE));
        } else {
                unsigned long end = addr + PAGE_SIZE;
                int incr = sun4c_vacinfo.linesize;
 
                for( ; addr < end; addr += incr)
                        __asm__ __volatile__("sta %%g0, [%0] %1\n\t" : :
                                             "r" (addr), "i" (ASI_FLUSHPG));
        }
}
 
/* The sun4c's do have an on chip store buffer.  And the way you
 * clear them out isn't so obvious.  The only way I can think of
 * to accomplish this is to read the current context register,
 * store the same value there, then do a bunch of nops for the
 * pipeline to clear itself completely.  This is only used for
 * dealing with memory errors, so it is not that critical.
 */
void sun4c_complete_all_stores(void)
{
        volatile int _unused;
 
        _unused = sun4c_get_context();
        sun4c_set_context(_unused);
        nop(); nop(); nop(); nop();
        nop(); nop(); nop(); nop();
        /* Is that enough? */
}
 
/* Bootup utility functions. */
static inline void sun4c_init_clean_segmap(unsigned char pseg)
{
        unsigned long vaddr;
 
        sun4c_put_segmap(0, pseg);
        for(vaddr = 0; vaddr < SUN4C_REAL_PGDIR_SIZE; vaddr+=PAGE_SIZE)
                sun4c_put_pte(vaddr, 0);
        sun4c_put_segmap(0, invalid_segment);
}
 
static inline void sun4c_init_clean_mmu(unsigned long kernel_end)
{
        unsigned long vaddr;
        unsigned char savectx, ctx;
 
        savectx = sun4c_get_context();
        kernel_end = SUN4C_REAL_PGDIR_ALIGN(kernel_end);
        for(ctx = 0; ctx < num_contexts; ctx++) {
                sun4c_set_context(ctx);
                for(vaddr = 0; vaddr < 0x20000000; vaddr += SUN4C_REAL_PGDIR_SIZE)
                        sun4c_put_segmap(vaddr, invalid_segment);
                for(vaddr = 0xe0000000; vaddr < KERNBASE; vaddr += SUN4C_REAL_PGDIR_SIZE)
                        sun4c_put_segmap(vaddr, invalid_segment);
                for(vaddr = kernel_end; vaddr < KADB_DEBUGGER_BEGVM; vaddr += SUN4C_REAL_PGDIR_SIZE)
                        sun4c_put_segmap(vaddr, invalid_segment);
                for(vaddr = LINUX_OPPROM_ENDVM; vaddr; vaddr += SUN4C_REAL_PGDIR_SIZE)
                        sun4c_put_segmap(vaddr, invalid_segment);
        }
        sun4c_set_context(ctx);
}
 
void sun4c_probe_vac(void)
{
        int propval;
 
        sun4c_disable_vac();
        sun4c_vacinfo.num_bytes = prom_getintdefault(prom_root_node,
                                                     "vac-size", 65536);
        sun4c_vacinfo.linesize = prom_getintdefault(prom_root_node,
                                                    "vac-linesize", 16);
        sun4c_vacinfo.num_lines =
                (sun4c_vacinfo.num_bytes / sun4c_vacinfo.linesize);
        switch(sun4c_vacinfo.linesize) {
        case 16:
                sun4c_vacinfo.log2lsize = 4;
                break;
        case 32:
                sun4c_vacinfo.log2lsize = 5;
                break;
        default:
                prom_printf("probe_vac: Didn't expect vac-linesize of %d, halting\n",
                            sun4c_vacinfo.linesize);
                prom_halt();
        };
 
        propval = prom_getintdefault(prom_root_node, "vac_hwflush", -1);
        sun4c_vacinfo.do_hwflushes = (propval == -1 ?
                                      prom_getintdefault(prom_root_node,
                                                         "vac-hwflush", 0) :
                                      propval);
 
        if(sun4c_vacinfo.num_bytes != 65536) {
                prom_printf("WEIRD Sun4C VAC cache size, tell davem");
                prom_halt();
        }
 
        sun4c_flush_all();
        sun4c_enable_vac();
}
 
static void sun4c_probe_mmu(void)
{
        num_segmaps = prom_getintdefault(prom_root_node, "mmu-npmg", 128);
        num_contexts = prom_getintdefault(prom_root_node, "mmu-nctx", 0x8);
}
 
static inline void sun4c_init_ss2_cache_bug(void)
{
        extern unsigned long start;
 
        if(idprom->id_machtype == (SM_SUN4C | SM_4C_SS2)) {
                /* Whee.. */
                printk("SS2 cache bug detected, uncaching trap table page\n");
                sun4c_flush_page((unsigned int) &start);
                sun4c_put_pte(((unsigned long) &start),
                        (sun4c_get_pte((unsigned long) &start) | _SUN4C_PAGE_NOCACHE));
        }
}
 
static inline unsigned long sun4c_init_alloc_dvma_pages(unsigned long start_mem)
{
        unsigned long addr, pte;
 
        for(addr = DVMA_VADDR; addr < DVMA_END; addr += PAGE_SIZE) {
                pte = (start_mem - PAGE_OFFSET) >> PAGE_SHIFT;
                pte |= (_SUN4C_PAGE_VALID | _SUN4C_PAGE_WRITE | _SUN4C_PAGE_NOCACHE);
                sun4c_put_pte(addr, pte);
                start_mem += PAGE_SIZE;
        }
        return start_mem;
}
 
/* TLB management. */
struct sun4c_mmu_entry {
        struct sun4c_mmu_entry *next;
        struct sun4c_mmu_entry *prev;
        unsigned long vaddr;
        unsigned char pseg;
        unsigned char locked;
};
static struct sun4c_mmu_entry mmu_entry_pool[256];
 
static void sun4c_init_mmu_entry_pool(void)
{
        int i;
 
        for(i=0; i < 256; i++) {
                mmu_entry_pool[i].pseg = i;
                mmu_entry_pool[i].next = 0;
                mmu_entry_pool[i].prev = 0;
                mmu_entry_pool[i].vaddr = 0;
                mmu_entry_pool[i].locked = 0;
        }
        mmu_entry_pool[invalid_segment].locked = 1;
}
 
static inline void fix_permissions(unsigned long vaddr, unsigned long bits_on,
                                   unsigned long bits_off)
{
        unsigned long start, end;
 
        end = vaddr + SUN4C_REAL_PGDIR_SIZE;
        for(start = vaddr; start < end; start += PAGE_SIZE)
                if(sun4c_get_pte(start) & _SUN4C_PAGE_VALID)
                        sun4c_put_pte(start, (sun4c_get_pte(start) | bits_on) &
                                      ~bits_off);
}
 
static inline void sun4c_init_map_kernelprom(unsigned long kernel_end)
{
        unsigned long vaddr;
        unsigned char pseg, ctx;
 
        for(vaddr = KADB_DEBUGGER_BEGVM;
            vaddr < LINUX_OPPROM_ENDVM;
            vaddr += SUN4C_REAL_PGDIR_SIZE) {
                pseg = sun4c_get_segmap(vaddr);
                if(pseg != invalid_segment) {
                        mmu_entry_pool[pseg].locked = 1;
                        for(ctx = 0; ctx < num_contexts; ctx++)
                                prom_putsegment(ctx, vaddr, pseg);
                        fix_permissions(vaddr, _SUN4C_PAGE_PRIV, 0);
                }
        }
        for(vaddr = KERNBASE; vaddr < kernel_end; vaddr += SUN4C_REAL_PGDIR_SIZE) {
                pseg = sun4c_get_segmap(vaddr);
                mmu_entry_pool[pseg].locked = 1;
                for(ctx = 0; ctx < num_contexts; ctx++)
                        prom_putsegment(ctx, vaddr, pseg);
                fix_permissions(vaddr, _SUN4C_PAGE_PRIV, _SUN4C_PAGE_NOCACHE);
        }
}
 
static void sun4c_init_lock_area(unsigned long start, unsigned long end)
{
        int i, ctx;
 
        while(start < end) {
                for(i=0; i < invalid_segment; i++)
                        if(!mmu_entry_pool[i].locked)
                                break;
                mmu_entry_pool[i].locked = 1;
                sun4c_init_clean_segmap(i);
                for(ctx = 0; ctx < num_contexts; ctx++)
                        prom_putsegment(ctx, start, mmu_entry_pool[i].pseg);
                start += SUN4C_REAL_PGDIR_SIZE;
        }
}
 
struct sun4c_mmu_ring {
        struct sun4c_mmu_entry ringhd;
        int num_entries;
};
static struct sun4c_mmu_ring sun4c_context_ring[16]; /* used user entries */
static struct sun4c_mmu_ring sun4c_ufree_ring;       /* free user entries */
static struct sun4c_mmu_ring sun4c_kernel_ring;      /* used kernel entries */
static struct sun4c_mmu_ring sun4c_kfree_ring;       /* free kernel entries */
 
static inline void sun4c_init_rings(void)
{
        int i;
        for(i=0; i<16; i++) {
                sun4c_context_ring[i].ringhd.next =
                        sun4c_context_ring[i].ringhd.prev =
                        &sun4c_context_ring[i].ringhd;
                sun4c_context_ring[i].num_entries = 0;
        }
        sun4c_ufree_ring.ringhd.next = sun4c_ufree_ring.ringhd.prev =
                &sun4c_ufree_ring.ringhd;
        sun4c_kernel_ring.ringhd.next = sun4c_kernel_ring.ringhd.prev =
                &sun4c_kernel_ring.ringhd;
        sun4c_kfree_ring.ringhd.next = sun4c_kfree_ring.ringhd.prev =
                &sun4c_kfree_ring.ringhd;
        sun4c_ufree_ring.num_entries = sun4c_kernel_ring.num_entries =
                sun4c_kfree_ring.num_entries = 0;
}
 
static inline void add_ring(struct sun4c_mmu_ring *ring, struct sun4c_mmu_entry *entry)
{
        struct sun4c_mmu_entry *head = &ring->ringhd;
 
        entry->prev = head;
        (entry->next = head->next)->prev = entry;
        head->next = entry;
        ring->num_entries++;
}
 
static inline void remove_ring(struct sun4c_mmu_ring *ring, struct sun4c_mmu_entry *entry)
{
        struct sun4c_mmu_entry *next = entry->next;
 
        (next->prev = entry->prev)->next = next;
        ring->num_entries--;
}
 
static inline void recycle_ring(struct sun4c_mmu_ring *ring, struct sun4c_mmu_entry *entry)
{
        struct sun4c_mmu_entry *head = &ring->ringhd;
        struct sun4c_mmu_entry *next = entry->next;
 
        (next->prev = entry->prev)->next = next;
        entry->prev = head; (entry->next = head->next)->prev = entry;
        head->next = entry;
        /* num_entries stays the same */
}
 
static inline void free_user_entry(int ctx, struct sun4c_mmu_entry *entry)
{
        remove_ring(sun4c_context_ring+ctx, entry);
        add_ring(&sun4c_ufree_ring, entry);
}
 
static inline void assign_user_entry(int ctx, struct sun4c_mmu_entry *entry)
{
        remove_ring(&sun4c_ufree_ring, entry);
        add_ring(sun4c_context_ring+ctx, entry);
}
 
static inline void free_kernel_entry(struct sun4c_mmu_entry *entry, struct sun4c_mmu_ring *ring)
{
        remove_ring(ring, entry);
        add_ring(&sun4c_kfree_ring, entry);
}
 
static inline void assign_kernel_entry(struct sun4c_mmu_entry *entry, struct sun4c_mmu_ring *ring)
{
        remove_ring(ring, entry);
        add_ring(&sun4c_kernel_ring, entry);
}
 
static inline void reassign_kernel_entry(struct sun4c_mmu_entry *entry)
{
        recycle_ring(&sun4c_kernel_ring, entry);
}
 
static void sun4c_init_fill_kernel_ring(int howmany)
{
        int i;
 
        while(howmany) {
                for(i=0; i < invalid_segment; i++)
                        if(!mmu_entry_pool[i].locked)
                                break;
                mmu_entry_pool[i].locked = 1;
                sun4c_init_clean_segmap(i);
                add_ring(&sun4c_kfree_ring, &mmu_entry_pool[i]);
                howmany--;
        }
}
 
static void sun4c_init_fill_user_ring(void)
{
        int i;
 
        for(i=0; i < invalid_segment; i++) {
                if(mmu_entry_pool[i].locked)
                        continue;
                sun4c_init_clean_segmap(i);
                add_ring(&sun4c_ufree_ring, &mmu_entry_pool[i]);
        }
}
 
static inline void sun4c_kernel_unmap(struct sun4c_mmu_entry *kentry)
{
        int savectx, ctx;
 
        savectx = sun4c_get_context();
        flush_user_windows();
        sun4c_flush_segment(kentry->vaddr);
        for(ctx = 0; ctx < num_contexts; ctx++) {
                sun4c_set_context(ctx);
                sun4c_put_segmap(kentry->vaddr, invalid_segment);
        }
        sun4c_set_context(savectx);
}
 
static inline void sun4c_kernel_map(struct sun4c_mmu_entry *kentry)
{
        int savectx, ctx;
 
        savectx = sun4c_get_context();
        flush_user_windows();
        for(ctx = 0; ctx < num_contexts; ctx++) {
                sun4c_set_context(ctx);
                sun4c_put_segmap(kentry->vaddr, kentry->pseg);
        }
        sun4c_set_context(savectx);
}
 
static inline void sun4c_user_unmap(struct sun4c_mmu_entry *uentry)
{
        sun4c_flush_segment(uentry->vaddr);
        sun4c_put_segmap(uentry->vaddr, invalid_segment);
}
 
static inline void sun4c_user_map(struct sun4c_mmu_entry *uentry)
{
        unsigned long start = uentry->vaddr;
        unsigned long end = start + SUN4C_REAL_PGDIR_SIZE;
 
        sun4c_put_segmap(uentry->vaddr, uentry->pseg);
        while(start < end) {
                sun4c_put_pte(start, 0);
                start += PAGE_SIZE;
        }
}
 
static inline void sun4c_demap_context(struct sun4c_mmu_ring *crp, unsigned char ctx)
{
        struct sun4c_mmu_entry *this_entry, *next_entry;
        int savectx = sun4c_get_context();
 
        this_entry = crp->ringhd.next;
        flush_user_windows();
        sun4c_set_context(ctx);
        while(crp->num_entries) {
                next_entry = this_entry->next;
                sun4c_user_unmap(this_entry);
                free_user_entry(ctx, this_entry);
                this_entry = next_entry;
        }
        sun4c_set_context(savectx);
}
 
static inline void sun4c_demap_one(struct sun4c_mmu_ring *crp, unsigned char ctx)
{
        struct sun4c_mmu_entry *entry = crp->ringhd.next;
        int savectx = sun4c_get_context();
 
        flush_user_windows();
        sun4c_set_context(ctx);
        sun4c_user_unmap(entry);
        free_user_entry(ctx, entry);
        sun4c_set_context(savectx);
}
 
/* Using this method to free up mmu entries eliminates a lot of
 * potential races since we have a kernel that incurs tlb
 * replacement faults.  There may be performance penalties.
 */
static inline struct sun4c_mmu_entry *sun4c_user_strategy(void)
{
        struct sun4c_mmu_ring *rp = 0;
        unsigned char mmuhog, i, ctx = 0;
 
        /* If some are free, return first one. */
        if(sun4c_ufree_ring.num_entries)
                return sun4c_ufree_ring.ringhd.next;
 
        /* Else free one up. */
        mmuhog = 0;
        for(i=0; i < num_contexts; i++) {
                if(sun4c_context_ring[i].num_entries > mmuhog) {
                        rp = &sun4c_context_ring[i];
                        mmuhog = rp->num_entries;
                        ctx = i;
                }
        }
        sun4c_demap_one(rp, ctx);
        return sun4c_ufree_ring.ringhd.next;
}
 
static inline struct sun4c_mmu_entry *sun4c_kernel_strategy(void)
{
        struct sun4c_mmu_entry *this_entry;
 
        /* If some are free, return first one. */
        if(sun4c_kfree_ring.num_entries)
                return sun4c_kfree_ring.ringhd.next;
 
        /* Else free one up. */
        this_entry = sun4c_kernel_ring.ringhd.prev;
        sun4c_kernel_unmap(this_entry);
        free_kernel_entry(this_entry, &sun4c_kernel_ring);
        return sun4c_kfree_ring.ringhd.next;
}
 
static inline void alloc_user_segment(unsigned long address, unsigned char ctx)
{
        struct sun4c_mmu_entry *entry;
 
        address &= SUN4C_REAL_PGDIR_MASK;
        entry = sun4c_user_strategy();
        assign_user_entry(ctx, entry);
        entry->vaddr = address;
        sun4c_user_map(entry);
}
 
static inline void alloc_kernel_segment(unsigned long address)
{
        struct sun4c_mmu_entry *entry;
 
        address &= SUN4C_REAL_PGDIR_MASK;
        entry = sun4c_kernel_strategy();
 
        assign_kernel_entry(entry, &sun4c_kfree_ring);
        entry->vaddr = address;
        sun4c_kernel_map(entry);
}
 
/* XXX Just like kernel tlb replacement we'd like to have a low level
 * XXX equivalent for user faults which need not go through the mm
 * XXX subsystem just to load a mmu entry.  But this might not be as
 * XXX feasible since we need to go through the kernel page tables
 * XXX for this process, which we currently don't lock into the mmu
 * XXX so we would fault with traps off... must think about this...
 */
static void sun4c_update_mmu_cache(struct vm_area_struct *vma, unsigned long address, pte_t pte)
{
        unsigned long flags;
 
        save_flags(flags); cli();
        address &= PAGE_MASK;
        if(sun4c_get_segmap(address) == invalid_segment)
                alloc_user_segment(address, sun4c_get_context());
        sun4c_put_pte(address, pte_val(pte));
        restore_flags(flags);
}
 
/* READ THIS:  If you put any diagnostic printing code in any of the kernel
 *             fault handling code you will lose badly.  This is the most
 *             delicate piece of code in the entire kernel, atomicity of
 *             kernel tlb replacement must be guaranteed.  This is why we
 *             have separate user and kernel allocation rings to alleviate
 *             as many bad interactions as possible.
 *
 * XXX Someday make this into a fast in-window trap handler to avoid
 * XXX any and all races.  *High* priority, also for performance.
 */
static void sun4c_quick_kernel_fault(unsigned long address)
{
        unsigned long end, flags;
 
        save_flags(flags); cli();
        address &= SUN4C_REAL_PGDIR_MASK;
        end = address + SUN4C_REAL_PGDIR_SIZE;
        if(sun4c_get_segmap(address) == invalid_segment)
                alloc_kernel_segment(address);
 
        if(address < SUN4C_VMALLOC_START) {
                unsigned long pte;
                pte = (address - PAGE_OFFSET) >> PAGE_SHIFT;
                pte |= pgprot_val(SUN4C_PAGE_KERNEL);
                /* Stupid pte tricks... */
                while(address < end) {
                        sun4c_put_pte(address, pte++);
                        address += PAGE_SIZE;
                }
        } else {
                pte_t *ptep;
 
                ptep = (pte_t *) (PAGE_MASK & pgd_val(swapper_pg_dir[address>>SUN4C_PGDIR_SHIFT]));
                ptep = (ptep + ((address >> PAGE_SHIFT) & (SUN4C_PTRS_PER_PTE - 1)));
                while(address < end) {
                        sun4c_put_pte(address, pte_val(*ptep++));
                        address += PAGE_SIZE;
                }
        }
        restore_flags(flags);
}
 
/*
 * 4 page buckets for task struct and kernel stack allocation.
 *
 * TASK_STACK_BEGIN
 * bucket[0]
 * bucket[1]
 *   [ ... ]
 * bucket[NR_TASKS-1]
 * TASK_STACK_BEGIN + (sizeof(struct task_bucket) * NR_TASKS)
 *
 * Each slot looks like:
 *
 *  page 1   --  task struct
 *  page 2   --  unmapped, for stack redzone (maybe use for pgd)
 *  page 3/4 --  kernel stack
 */
 
struct task_bucket {
        struct task_struct task;
        char _unused1[PAGE_SIZE - sizeof(struct task_struct)];
        char kstack[(PAGE_SIZE*3)];
};
 
struct task_bucket *sun4c_bucket[NR_TASKS];
 
#define BUCKET_EMPTY     ((struct task_bucket *) 0)
#define BUCKET_SIZE      (PAGE_SIZE << 2)
#define BUCKET_SHIFT     14        /* log2(sizeof(struct task_bucket)) */
#define BUCKET_NUM(addr) ((((addr) - SUN4C_LOCK_VADDR) >> BUCKET_SHIFT))
#define BUCKET_ADDR(num) (((num) << BUCKET_SHIFT) + SUN4C_LOCK_VADDR)
#define BUCKET_PTE(page)       \
        ((((page) - PAGE_OFFSET) >> PAGE_SHIFT) | pgprot_val(SUN4C_PAGE_KERNEL))
#define BUCKET_PTE_PAGE(pte)   \
        (PAGE_OFFSET + (((pte) & 0xffff) << PAGE_SHIFT))
 
static inline void get_task_segment(unsigned long addr)
{
        struct sun4c_mmu_entry *stolen;
        unsigned long flags;
 
        save_flags(flags); cli();
        addr &= SUN4C_REAL_PGDIR_MASK;
        stolen = sun4c_user_strategy();
        remove_ring(&sun4c_ufree_ring, stolen);
        stolen->vaddr = addr;
        sun4c_kernel_map(stolen);
        restore_flags(flags);
}
 
static inline void free_task_segment(unsigned long addr)
{
        struct sun4c_mmu_entry *entry;
        unsigned long flags;
        unsigned char pseg;
 
        save_flags(flags); cli();
        addr &= SUN4C_REAL_PGDIR_MASK;
        pseg = sun4c_get_segmap(addr);
        entry = &mmu_entry_pool[pseg];
        sun4c_flush_segment(addr);
        sun4c_kernel_unmap(entry);
        add_ring(&sun4c_ufree_ring, entry);
        restore_flags(flags);
}
 
static inline void garbage_collect(int entry)
{
        int start, end;
 
        /* 16 buckets per segment... */
        entry &= ~15;
        start = entry;
        for(end = (start + 16); start < end; start++)
                if(sun4c_bucket[start] != BUCKET_EMPTY)
                        return;
        /* Entire segment empty, release it. */
        free_task_segment(BUCKET_ADDR(entry));
}
 
static struct task_struct *sun4c_alloc_task_struct(void)
{
        unsigned long addr, page;
        int entry;
 
        page = get_free_page(GFP_KERNEL);
        if(!page)
                return (struct task_struct *) 0;
        /* XXX Bahh, linear search too slow, use hash
         * XXX table in final implementation.  Or
         * XXX keep track of first free when we free
         * XXX a bucket... anything but this.
         */
        for(entry = 0; entry < NR_TASKS; entry++)
                if(sun4c_bucket[entry] == BUCKET_EMPTY)
                        break;
        if(entry == NR_TASKS) {
                free_page(page);
                return (struct task_struct *) 0;
        }
        addr = BUCKET_ADDR(entry);
        sun4c_bucket[entry] = (struct task_bucket *) addr;
        if(sun4c_get_segmap(addr) == invalid_segment)
                get_task_segment(addr);
        sun4c_put_pte(addr, BUCKET_PTE(page));
        return (struct task_struct *) addr;
}
 
static unsigned long sun4c_alloc_kernel_stack(struct task_struct *tsk)
{
        unsigned long saddr = (unsigned long) tsk;
        unsigned long page[3];
 
        if(!saddr)
                return 0;
        page[0] = get_free_page(GFP_KERNEL);
        if(!page[0])
                return 0;
        page[1] = get_free_page(GFP_KERNEL);
        if(!page[1]) {
                free_page(page[0]);
                return 0;
        }
        page[2] = get_free_page(GFP_KERNEL);
        if(!page[2]) {
                free_page(page[0]);
                free_page(page[1]);
                return 0;
        }
        saddr += PAGE_SIZE;
        sun4c_put_pte(saddr, BUCKET_PTE(page[0]));
        sun4c_put_pte(saddr + PAGE_SIZE, BUCKET_PTE(page[1]));
        sun4c_put_pte(saddr + (PAGE_SIZE<<1), BUCKET_PTE(page[2]));
        return saddr;
}
 
static void sun4c_free_kernel_stack(unsigned long stack)
{
        unsigned long page[3];
 
        page[0] = BUCKET_PTE_PAGE(sun4c_get_pte(stack));
        page[1] = BUCKET_PTE_PAGE(sun4c_get_pte(stack+PAGE_SIZE));
        page[2] = BUCKET_PTE_PAGE(sun4c_get_pte(stack+(PAGE_SIZE<<1)));
        sun4c_flush_segment(stack & SUN4C_REAL_PGDIR_MASK);
        sun4c_put_pte(stack, 0);
        sun4c_put_pte(stack + PAGE_SIZE, 0);
        sun4c_put_pte(stack + (PAGE_SIZE<<1), 0);
        free_page(page[0]);
        free_page(page[1]);
        free_page(page[2]);
}
 
static void sun4c_free_task_struct(struct task_struct *tsk)
{
        unsigned long tsaddr = (unsigned long) tsk;
        unsigned long page = BUCKET_PTE_PAGE(sun4c_get_pte(tsaddr));
        int entry = BUCKET_NUM(tsaddr);
 
        sun4c_flush_segment(tsaddr & SUN4C_REAL_PGDIR_MASK);
        sun4c_put_pte(tsaddr, 0);
        sun4c_bucket[entry] = BUCKET_EMPTY;
        free_page(page);
        garbage_collect(entry);
}
 
static void sun4c_init_buckets(void)
{
        int entry;
 
        if(sizeof(struct task_bucket) != (PAGE_SIZE << 2)) {
                prom_printf("task bucket not 4 pages!\n");
                prom_halt();
        }
        for(entry = 0; entry < NR_TASKS; entry++)
                sun4c_bucket[entry] = BUCKET_EMPTY;
}
 
static unsigned long sun4c_iobuffer_start;
static unsigned long sun4c_iobuffer_end;
static unsigned long *sun4c_iobuffer_map;
static int iobuffer_map_size;
 
/*
 * Alias our pages so they do not cause a trap.
 * Also one page may be aliased into several I/O areas and we may
 * finish these I/O separately.
 */
static char *sun4c_lockarea(char *vaddr, unsigned long size)
{
        unsigned long base, scan;
        unsigned long npages;
        unsigned long vpage;
        unsigned long pte;
        unsigned long apage;
 
        npages = (((unsigned long)vaddr & ~PAGE_MASK) +
                  size + (PAGE_SIZE-1)) >> PAGE_SHIFT;
 
        scan = 0;
        for (;;) {
                scan = find_next_zero_bit(sun4c_iobuffer_map,
                                          iobuffer_map_size, scan);
                if ((base = scan) + npages > iobuffer_map_size) goto abend;
                for (;;) {
                        if (scan >= base + npages) goto found;
                        if (test_bit(scan, sun4c_iobuffer_map)) break;
                        scan++;
                }
        }
 
found:
        vpage = ((unsigned long) vaddr) & PAGE_MASK;
        for (scan = base; scan < base+npages; scan++) {
                pte = ((vpage-PAGE_OFFSET) >> PAGE_SHIFT);
                pte |= pgprot_val(SUN4C_PAGE_KERNEL);
                pte |= _SUN4C_PAGE_NOCACHE;
                set_bit(scan, sun4c_iobuffer_map);
                apage = (scan << PAGE_SHIFT) + sun4c_iobuffer_start;
                sun4c_flush_page(vpage);
                sun4c_put_pte(apage, pte);
                vpage += PAGE_SIZE;
        }
        return (char *) ((base << PAGE_SHIFT) + sun4c_iobuffer_start +
                         (((unsigned long) vaddr) & ~PAGE_MASK));
 
abend:
        printk("DMA vaddr=0x%p size=%08lx\n", vaddr, size);
        panic("Out of iobuffer table");
        return 0;
}
 
static void sun4c_unlockarea(char *vaddr, unsigned long size)
{
        unsigned long vpage, npages;
 
        vpage = (unsigned long)vaddr & PAGE_MASK;
        npages = (((unsigned long)vaddr & ~PAGE_MASK) +
                  size + (PAGE_SIZE-1)) >> PAGE_SHIFT;
        while (npages != 0) {
                --npages;
                sun4c_put_pte(vpage, 0);
                clear_bit((vpage - sun4c_iobuffer_start) >> PAGE_SHIFT,
                          sun4c_iobuffer_map);
                vpage += PAGE_SIZE;
        }
}
 
/* Note the scsi code at init time passes to here buffers
 * which sit on the kernel stack, those are already locked
 * by implication and fool the page locking code above
 * if passed to by mistake.
 */
static char *sun4c_get_scsi_one(char *bufptr, unsigned long len, struct linux_sbus *sbus)
{
        unsigned long page;
 
        page = ((unsigned long) bufptr) & PAGE_MASK;
        if(page > high_memory)
                return bufptr; /* already locked */
        return sun4c_lockarea(bufptr, len);
}
 
static void sun4c_get_scsi_sgl(struct mmu_sglist *sg, int sz, struct linux_sbus *sbus)
{
        while(sz >= 0) {
                sg[sz].alt_addr = sun4c_lockarea(sg[sz].addr, sg[sz].len);
                sz--;
        }
}
 
static void sun4c_release_scsi_one(char *bufptr, unsigned long len, struct linux_sbus *sbus)
{
        unsigned long page = (unsigned long) bufptr;
 
        if(page < sun4c_iobuffer_start)
                return; /* On kernel stack or similar, see above */
        sun4c_unlockarea(bufptr, len);
}
 
static void sun4c_release_scsi_sgl(struct mmu_sglist *sg, int sz, struct linux_sbus *sbus)
{
        while(sz >= 0) {
                sun4c_unlockarea(sg[sz].alt_addr, sg[sz].len);
                sg[sz].alt_addr = 0;
                sz--;
        }
}
 
#define TASK_ENTRY_SIZE    BUCKET_SIZE /* see above */
#define LONG_ALIGN(x) (((x)+(sizeof(long))-1)&~((sizeof(long))-1))
 
struct vm_area_struct sun4c_kstack_vma;
 
static unsigned long sun4c_init_lock_areas(unsigned long start_mem)
{
        unsigned long sun4c_taskstack_start;
        unsigned long sun4c_taskstack_end;
        int bitmap_size;
 
        sun4c_init_buckets();
        sun4c_taskstack_start = SUN4C_LOCK_VADDR;
        sun4c_taskstack_end = (sun4c_taskstack_start +
                               (TASK_ENTRY_SIZE * NR_TASKS));
        if(sun4c_taskstack_end >= SUN4C_LOCK_END) {
                prom_printf("Too many tasks, decrease NR_TASKS please.\n");
                prom_halt();
        }
 
        sun4c_iobuffer_start = SUN4C_REAL_PGDIR_ALIGN(sun4c_taskstack_end);
        sun4c_iobuffer_end = SUN4C_LOCK_END;
        bitmap_size = (sun4c_iobuffer_end - sun4c_iobuffer_start) >> PAGE_SHIFT;
        bitmap_size = (bitmap_size + 7) >> 3;
        bitmap_size = LONG_ALIGN(bitmap_size);
        iobuffer_map_size = bitmap_size << 3;
        sun4c_iobuffer_map = (unsigned long *) start_mem;
        memset((void *) start_mem, 0, bitmap_size);
        start_mem += bitmap_size;
 
        /* Now get us some mmu entries for I/O maps. */
        sun4c_init_lock_area(sun4c_iobuffer_start, sun4c_iobuffer_end);
        sun4c_kstack_vma.vm_mm = init_task.mm;
        sun4c_kstack_vma.vm_start = sun4c_taskstack_start;
        sun4c_kstack_vma.vm_end = sun4c_taskstack_end;
        sun4c_kstack_vma.vm_page_prot = PAGE_SHARED;
        sun4c_kstack_vma.vm_flags = VM_READ | VM_WRITE | VM_EXEC;
        insert_vm_struct(&init_task, &sun4c_kstack_vma);
        return start_mem;
}
 
/* Cache flushing on the sun4c. */
static void sun4c_flush_cache_all(void)
{
        unsigned long start, end;
 
        /* Clear all tags in the sun4c cache.
         * The cache is write through so this is safe.
         */
        start = AC_CACHETAGS;
        end = start + sun4c_vacinfo.num_bytes;
        flush_user_windows();
        while(start < end) {
                __asm__ __volatile__("sta %%g0, [%0] %1\n\t" : :
                                     "r" (start), "i" (ASI_CONTROL));
                start += sun4c_vacinfo.linesize;
        }
}
 
static void sun4c_flush_cache_mm(struct mm_struct *mm)
{
        unsigned long flags;
        int octx;
 
#ifndef __SMP__
        if(mm->context != NO_CONTEXT) {
#endif
                octx = sun4c_get_context();
                save_flags(flags); cli();
                flush_user_windows();
                sun4c_set_context(mm->context);
                sun4c_flush_context();
                sun4c_set_context(octx);
                restore_flags(flags);
#ifndef __SMP__
        }
#endif
}
 
static void sun4c_flush_cache_range(struct mm_struct *mm, unsigned long start, unsigned long end)
{
        unsigned long flags;
        int size, octx;
 
#ifndef __SMP__
        if(mm->context != NO_CONTEXT) {
#endif
                size = start - end;
 
                flush_user_windows();
 
                if(size >= sun4c_vacinfo.num_bytes)
                        goto flush_it_all;
 
                save_flags(flags); cli();
                octx = sun4c_get_context();
                sun4c_set_context(mm->context);
 
                if(size <= (PAGE_SIZE << 1)) {
                        start &= PAGE_MASK;
                        while(start < end) {
                                sun4c_flush_page(start);
                                start += PAGE_SIZE;
                        };
                } else {
                        start &= SUN4C_REAL_PGDIR_MASK;
                        while(start < end) {
                                sun4c_flush_segment(start);
                                start += SUN4C_REAL_PGDIR_SIZE;
                        }
                }
                sun4c_set_context(octx);
                restore_flags(flags);
#ifndef __SMP__
        }
#endif
        return;
 
flush_it_all:
        /* Cache size bounded flushing, thank you. */
        sun4c_flush_cache_all();
}
 
static void sun4c_flush_cache_page(struct vm_area_struct *vma, unsigned long page)
{
        unsigned long flags;
        int octx;
        struct mm_struct *mm = vma->vm_mm;
 
        /* Sun4c has no separate I/D caches so cannot optimize for non
         * text page flushes.
         */
#ifndef __SMP__
        if(mm->context != NO_CONTEXT) {
#endif
                octx = sun4c_get_context();
                save_flags(flags); cli();
                flush_user_windows();
                sun4c_set_context(mm->context);
                sun4c_flush_page(page);
                sun4c_set_context(octx);
                restore_flags(flags);
#ifndef __SMP__
        }
#endif
}
 
/* Sun4c cache is write-through, so no need to validate main memory
 * during a page copy in kernel space.
 */
static void sun4c_flush_page_to_ram(unsigned long page)
{
}
 
/* TLB flushing on the sun4c.  These routines count on the cache
 * flushing code to flush the user register windows so that we need
 * not do so when we get here.
 */
 
static void sun4c_flush_tlb_all(void)
{
        struct sun4c_mmu_entry *this_entry, *next_entry;
        unsigned long flags;
        int savectx, ctx;
 
        save_flags(flags); cli();
        this_entry = sun4c_kernel_ring.ringhd.next;
        savectx = sun4c_get_context();
        while(sun4c_kernel_ring.num_entries) {
                next_entry = this_entry->next;
                for(ctx = 0; ctx < num_contexts; ctx++) {
                        sun4c_set_context(ctx);
                        sun4c_put_segmap(this_entry->vaddr, invalid_segment);
                }
                free_kernel_entry(this_entry, &sun4c_kernel_ring);
                this_entry = next_entry;
        }
        sun4c_set_context(savectx);
        restore_flags(flags);
}
 
static void sun4c_flush_tlb_mm(struct mm_struct *mm)
{
        struct sun4c_mmu_entry *this_entry, *next_entry;
        struct sun4c_mmu_ring *crp;
        int savectx, ctx;
 
#ifndef __SMP__
        if(mm->context != NO_CONTEXT) {
#endif
                crp = &sun4c_context_ring[mm->context];
                savectx = sun4c_get_context();
                ctx = mm->context;
                this_entry = crp->ringhd.next;
                sun4c_set_context(mm->context);
                while(crp->num_entries) {
                        next_entry = this_entry->next;
                        sun4c_user_unmap(this_entry);
                        free_user_entry(ctx, this_entry);
                        this_entry = next_entry;
                }
                sun4c_set_context(savectx);
#ifndef __SMP__
        }
#endif
}
 
static void sun4c_flush_tlb_range(struct mm_struct *mm, unsigned long start, unsigned long end)
{
        struct sun4c_mmu_entry *this_entry;
        unsigned char pseg, savectx;
 
#ifndef __SMP__
        if(mm->context == NO_CONTEXT)
                return;
#endif
        flush_user_windows();
        savectx = sun4c_get_context();
        sun4c_set_context(mm->context);
        start &= SUN4C_REAL_PGDIR_MASK;
        while(start < end) {
                pseg = sun4c_get_segmap(start);
                if(pseg == invalid_segment)
                        goto next_one;
                this_entry = &mmu_entry_pool[pseg];
                sun4c_put_segmap(this_entry->vaddr, invalid_segment);
                free_user_entry(mm->context, this_entry);
        next_one:
                start += SUN4C_REAL_PGDIR_SIZE;
        }
        sun4c_set_context(savectx);
}
 
static void sun4c_flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
{
        struct mm_struct *mm = vma->vm_mm;
        int savectx;
 
#ifndef __SMP__
        if(mm->context != NO_CONTEXT) {
#endif
                savectx = sun4c_get_context();
                sun4c_set_context(mm->context);
                page &= PAGE_MASK;
                if(sun4c_get_pte(page) & _SUN4C_PAGE_VALID)
                        sun4c_put_pte(page, 0);
                sun4c_set_context(savectx);
#ifndef __SMP__
        }
#endif
}
 
/* Sun4c mmu hardware doesn't update the dirty bit in the pte's
 * for us, so we do it in software.
 */
static void sun4c_set_pte(pte_t *ptep, pte_t pte)
{
 
        if((pte_val(pte) & (_SUN4C_PAGE_WRITE|_SUN4C_PAGE_DIRTY)) ==
           _SUN4C_PAGE_WRITE)
                pte_val(pte) |= _SUN4C_PAGE_DIRTY;
 
        *ptep = pte;
}
 
/* static */ void sun4c_mapioaddr(unsigned long physaddr, unsigned long virt_addr,
                     int bus_type, int rdonly)
{
        unsigned long page_entry;
 
        page_entry = ((physaddr >> PAGE_SHIFT) & 0xffff);
        page_entry |= (_SUN4C_PAGE_VALID | _SUN4C_PAGE_WRITE |
                       _SUN4C_PAGE_NOCACHE | _SUN4C_PAGE_IO);
        if(rdonly)
                page_entry &= (~_SUN4C_PAGE_WRITE);
        sun4c_flush_page(virt_addr);
        sun4c_put_pte(virt_addr, page_entry);
}
 
static inline void sun4c_alloc_context(struct mm_struct *mm)
{
        struct ctx_list *ctxp;
 
        ctxp = ctx_free.next;
        if(ctxp != &ctx_free) {
                remove_from_ctx_list(ctxp);
                add_to_used_ctxlist(ctxp);
                mm->context = ctxp->ctx_number;
                ctxp->ctx_mm = mm;
                return;
        }
        ctxp = ctx_used.next;
        if(ctxp->ctx_mm == current->mm)
                ctxp = ctxp->next;
        if(ctxp == &ctx_used)
                panic("out of mmu contexts");
        remove_from_ctx_list(ctxp);
        add_to_used_ctxlist(ctxp);
        ctxp->ctx_mm->context = NO_CONTEXT;
        ctxp->ctx_mm = mm;
        mm->context = ctxp->ctx_number;
        sun4c_demap_context(&sun4c_context_ring[ctxp->ctx_number], ctxp->ctx_number);
}
 
#if some_day_soon /* We need some tweaking to start using this */
extern void force_user_fault(unsigned long, int);
 
void sun4c_switch_heuristic(struct pt_regs *regs)
{
        unsigned long sp = regs->u_regs[UREG_FP];
        unsigned long sp2 = sp + REGWIN_SZ - 0x8;
 
        force_user_fault(regs->pc, 0);
        force_user_fault(sp, 0);
        if((sp&PAGE_MASK) != (sp2&PAGE_MASK))
                force_user_fault(sp2, 0);
}
#endif
 
static void sun4c_switch_to_context(struct task_struct *tsk)
{
        /* Kernel threads can execute in any context and so can tasks
         * sleeping in the middle of exiting. If this task has already
         * been allocated a piece of the mmu realestate, just jump to
         * it.
         */
        if((tsk->tss.flags & SPARC_FLAG_KTHREAD) ||
           (tsk->flags & PF_EXITING))
                return;
        if(tsk->mm->context == NO_CONTEXT)
                sun4c_alloc_context(tsk->mm);
 
        sun4c_set_context(tsk->mm->context);
}
 
static void sun4c_flush_hook(void)
{
        if(current->tss.flags & SPARC_FLAG_KTHREAD) {
                sun4c_alloc_context(current->mm);
                sun4c_set_context(current->mm->context);
        }
}
 
static void sun4c_exit_hook(void)
{
        struct ctx_list *ctx_old;
        struct mm_struct *mm = current->mm;
 
        if(mm->context != NO_CONTEXT) {
                sun4c_demap_context(&sun4c_context_ring[mm->context], mm->context);
                ctx_old = ctx_list_pool + mm->context;
                remove_from_ctx_list(ctx_old);
                add_to_free_ctxlist(ctx_old);
                mm->context = NO_CONTEXT;
        }
}
 
static char s4cinfo[512];
 
static char *sun4c_mmu_info(void)
{
        int used_user_entries, i;
 
        used_user_entries = 0;
        for(i=0; i < num_contexts; i++)
                used_user_entries += sun4c_context_ring[i].num_entries;
 
        sprintf(s4cinfo, "vacsize\t\t: %d bytes\n"
                "vachwflush\t: %s\n"
                "vaclinesize\t: %d bytes\n"
                "mmuctxs\t\t: %d\n"
                "mmupsegs\t: %d\n"
                "usedpsegs\t: %d\n"
                "ufreepsegs\t: %d\n"
                "context\t\t: %d flushes\n"
                "segment\t\t: %d flushes\n"
                "page\t\t: %d flushes\n",
                sun4c_vacinfo.num_bytes,
                (sun4c_vacinfo.do_hwflushes ? "yes" : "no"),
                sun4c_vacinfo.linesize,
                num_contexts,
                (invalid_segment + 1),
                used_user_entries,
                sun4c_ufree_ring.num_entries,
                ctxflushes, segflushes, pageflushes);
 
        return s4cinfo;
}
 
/* Nothing below here should touch the mmu hardware nor the mmu_entry
 * data structures.
 */
 
static unsigned int sun4c_pmd_align(unsigned int addr) { return SUN4C_PMD_ALIGN(addr); }
static unsigned int sun4c_pgdir_align(unsigned int addr) { return SUN4C_PGDIR_ALIGN(addr); }
 
/* First the functions which the mid-level code uses to directly
 * manipulate the software page tables.  Some defines since we are
 * emulating the i386 page directory layout.
 */
#define PGD_PRESENT  0x001
#define PGD_RW       0x002
#define PGD_USER     0x004
#define PGD_ACCESSED 0x020
#define PGD_DIRTY    0x040
#define PGD_TABLE    (PGD_PRESENT | PGD_RW | PGD_USER | PGD_ACCESSED | PGD_DIRTY)
 
static unsigned long sun4c_vmalloc_start(void)
{
        return SUN4C_VMALLOC_START;
}
 
static int sun4c_pte_none(pte_t pte)            { return !pte_val(pte); }
static int sun4c_pte_present(pte_t pte)         { return pte_val(pte) & _SUN4C_PAGE_VALID; }
static void sun4c_pte_clear(pte_t *ptep)        { pte_val(*ptep) = 0; }
 
static int sun4c_pmd_none(pmd_t pmd)            { return !pmd_val(pmd); }
static int sun4c_pmd_bad(pmd_t pmd)
{
        return (pmd_val(pmd) & ~PAGE_MASK) != PGD_TABLE || pmd_val(pmd) > high_memory;
}
 
static int sun4c_pmd_present(pmd_t pmd)         { return pmd_val(pmd) & PGD_PRESENT; }
static void sun4c_pmd_clear(pmd_t *pmdp)        { pmd_val(*pmdp) = 0; }
 
static int sun4c_pgd_none(pgd_t pgd)            { return 0; }
static int sun4c_pgd_bad(pgd_t pgd)             { return 0; }
static int sun4c_pgd_present(pgd_t pgd)         { return 1; }
static void sun4c_pgd_clear(pgd_t * pgdp)       { }
 
/*
 * The following only work if pte_present() is true.
 * Undefined behaviour if not..
 */
static int sun4c_pte_write(pte_t pte)           { return pte_val(pte) & _SUN4C_PAGE_WRITE; }
static int sun4c_pte_dirty(pte_t pte)           { return pte_val(pte) & _SUN4C_PAGE_DIRTY; }
static int sun4c_pte_young(pte_t pte)           { return pte_val(pte) & _SUN4C_PAGE_REF; }
 
static pte_t sun4c_pte_wrprotect(pte_t pte)     { pte_val(pte) &= ~_SUN4C_PAGE_WRITE; return pte; }
static pte_t sun4c_pte_mkclean(pte_t pte)       { pte_val(pte) &= ~_SUN4C_PAGE_DIRTY; return pte; }
static pte_t sun4c_pte_mkold(pte_t pte)         { pte_val(pte) &= ~_SUN4C_PAGE_REF; return pte; }
static pte_t sun4c_pte_mkwrite(pte_t pte)       { pte_val(pte) |= _SUN4C_PAGE_WRITE; return pte; }
static pte_t sun4c_pte_mkdirty(pte_t pte)       { pte_val(pte) |= _SUN4C_PAGE_DIRTY; return pte; }
static pte_t sun4c_pte_mkyoung(pte_t pte)       { pte_val(pte) |= _SUN4C_PAGE_REF; return pte; }
 
/*
 * Conversion functions: convert a page and protection to a page entry,
 * and a page entry and page directory to the page they refer to.
 */
static pte_t sun4c_mk_pte(unsigned long page, pgprot_t pgprot)
{
        return __pte(((page - PAGE_OFFSET) >> PAGE_SHIFT) | pgprot_val(pgprot));
}
 
static pte_t sun4c_mk_pte_io(unsigned long page, pgprot_t pgprot, int space)
{
        return __pte(((page - PAGE_OFFSET) >> PAGE_SHIFT) | pgprot_val(pgprot));
}
 
static pte_t sun4c_pte_modify(pte_t pte, pgprot_t newprot)
{
        return __pte((pte_val(pte) & _SUN4C_PAGE_CHG_MASK) | pgprot_val(newprot));
}
 
static unsigned long sun4c_pte_page(pte_t pte)
{
        return (PAGE_OFFSET + ((pte_val(pte) & 0xffff) << (PAGE_SHIFT)));
}
 
static unsigned long sun4c_pmd_page(pmd_t pmd)
{
        return (pmd_val(pmd) & PAGE_MASK);
}
 
/* to find an entry in a page-table-directory */
static pgd_t *sun4c_pgd_offset(struct mm_struct * mm, unsigned long address)
{
        return mm->pgd + (address >> SUN4C_PGDIR_SHIFT);
}
 
/* Find an entry in the second-level page table.. */
static pmd_t *sun4c_pmd_offset(pgd_t * dir, unsigned long address)
{
        return (pmd_t *) dir;
}
 
/* Find an entry in the third-level page table.. */
static pte_t *sun4c_pte_offset(pmd_t * dir, unsigned long address)
{
        return (pte_t *) sun4c_pmd_page(*dir) + ((address >> PAGE_SHIFT) & (SUN4C_PTRS_PER_PTE - 1));
}
 
/* Update the root mmu directory. */
static void sun4c_update_rootmmu_dir(struct task_struct *tsk, pgd_t *pgdir)
{
}
 
/* Allocate and free page tables. The xxx_kernel() versions are
 * used to allocate a kernel page table - this turns on ASN bits
 * if any, and marks the page tables reserved.
 */
static void sun4c_pte_free_kernel(pte_t *pte)
{
        free_page((unsigned long) pte);
}
 
static pte_t *sun4c_pte_alloc_kernel(pmd_t *pmd, unsigned long address)
{
        address = (address >> PAGE_SHIFT) & (SUN4C_PTRS_PER_PTE - 1);
        if (sun4c_pmd_none(*pmd)) {
                pte_t *page = (pte_t *) get_free_page(GFP_KERNEL);
                if (sun4c_pmd_none(*pmd)) {
                        if (page) {
                                pmd_val(*pmd) = PGD_TABLE | (unsigned long) page;
                                return page + address;
                        }
                        pmd_val(*pmd) = PGD_TABLE | (unsigned long) BAD_PAGETABLE;
                        return NULL;
                }
                free_page((unsigned long) page);
        }
        if (sun4c_pmd_bad(*pmd)) {
                printk("Bad pmd in pte_alloc_kernel: %08lx\n", pmd_val(*pmd));
                pmd_val(*pmd) = PGD_TABLE | (unsigned long) BAD_PAGETABLE;
                return NULL;
        }
        return (pte_t *) sun4c_pmd_page(*pmd) + address;
}
 
/*
 * allocating and freeing a pmd is trivial: the 1-entry pmd is
 * inside the pgd, so has no extra memory associated with it.
 */
static void sun4c_pmd_free_kernel(pmd_t *pmd)
{
        pmd_val(*pmd) = 0;
}
 
static pmd_t *sun4c_pmd_alloc_kernel(pgd_t *pgd, unsigned long address)
{
        return (pmd_t *) pgd;
}
 
static void sun4c_pte_free(pte_t *pte)
{
        free_page((unsigned long) pte);
}
 
static pte_t *sun4c_pte_alloc(pmd_t * pmd, unsigned long address)
{
        address = (address >> PAGE_SHIFT) & (SUN4C_PTRS_PER_PTE - 1);
        if (sun4c_pmd_none(*pmd)) {
                pte_t *page = (pte_t *) get_free_page(GFP_KERNEL);
                if (sun4c_pmd_none(*pmd)) {
                        if (page) {
                                pmd_val(*pmd) = PGD_TABLE | (unsigned long) page;
                                return page + address;
                        }
                        pmd_val(*pmd) = PGD_TABLE | (unsigned long) BAD_PAGETABLE;
                        return NULL;
                }
                free_page((unsigned long) page);
        }
        if (sun4c_pmd_bad(*pmd)) {
                printk("Bad pmd in pte_alloc: %08lx\n", pmd_val(*pmd));
                pmd_val(*pmd) = PGD_TABLE | (unsigned long) BAD_PAGETABLE;
                return NULL;
        }
        return (pte_t *) sun4c_pmd_page(*pmd) + address;
}
 
/*
 * allocating and freeing a pmd is trivial: the 1-entry pmd is
 * inside the pgd, so has no extra memory associated with it.
 */
static void sun4c_pmd_free(pmd_t * pmd)
{
        pmd_val(*pmd) = 0;
}
 
static pmd_t *sun4c_pmd_alloc(pgd_t * pgd, unsigned long address)
{
        return (pmd_t *) pgd;
}
 
static void sun4c_pgd_free(pgd_t *pgd)
{
        free_page((unsigned long) pgd);
}
 
static pgd_t *sun4c_pgd_alloc(void)
{
        return (pgd_t *) get_free_page(GFP_KERNEL);
}
 
#define SUN4C_KERNEL_BUCKETS   16
extern unsigned long free_area_init(unsigned long, unsigned long);
extern unsigned long sparc_context_init(unsigned long, int);
extern unsigned long end;
 
unsigned long sun4c_paging_init(unsigned long start_mem, unsigned long end_mem)
{
        int i, cnt;
        unsigned long kernel_end;
 
        kernel_end = (unsigned long) &end;
        kernel_end += (SUN4C_REAL_PGDIR_SIZE * 3);
        kernel_end = SUN4C_REAL_PGDIR_ALIGN(kernel_end);
        sun4c_probe_mmu();
        invalid_segment = (num_segmaps - 1);
        sun4c_init_mmu_entry_pool();
        sun4c_init_rings();
        sun4c_init_map_kernelprom(kernel_end);
        sun4c_init_clean_mmu(kernel_end);
        sun4c_init_fill_kernel_ring(SUN4C_KERNEL_BUCKETS);
        sun4c_init_lock_area(IOBASE_VADDR, IOBASE_END);
        sun4c_init_lock_area(DVMA_VADDR, DVMA_END);
        start_mem = sun4c_init_lock_areas(start_mem);
        sun4c_init_fill_user_ring();
 
        sun4c_set_context(0);
        memset(swapper_pg_dir, 0, PAGE_SIZE);
        memset(pg0, 0, PAGE_SIZE);
        /* Save work later. */
        pgd_val(swapper_pg_dir[SUN4C_VMALLOC_START>>SUN4C_PGDIR_SHIFT]) =
                PGD_TABLE | (unsigned long) pg0;
        sun4c_init_ss2_cache_bug();
        start_mem = PAGE_ALIGN(start_mem);
        start_mem = sun4c_init_alloc_dvma_pages(start_mem);
        start_mem = sparc_context_init(start_mem, num_contexts);
        start_mem = free_area_init(start_mem, end_mem);
        cnt = 0;
        for(i = 0; i < num_segmaps; i++)
                if(mmu_entry_pool[i].locked)
                        cnt++;
        printk("SUN4C: %d mmu entries for the kernel\n", cnt);
        return start_mem;
}
 
/* Load up routines and constants for sun4c mmu */
void ld_mmu_sun4c(void)
{
        printk("Loading sun4c MMU routines\n");
 
        /* First the constants */
        pmd_shift = SUN4C_PMD_SHIFT;
        pmd_size = SUN4C_PMD_SIZE;
        pmd_mask = SUN4C_PMD_MASK;
        pgdir_shift = SUN4C_PGDIR_SHIFT;
        pgdir_size = SUN4C_PGDIR_SIZE;
        pgdir_mask = SUN4C_PGDIR_MASK;
 
        ptrs_per_pte = SUN4C_PTRS_PER_PTE;
        ptrs_per_pmd = SUN4C_PTRS_PER_PMD;
        ptrs_per_pgd = SUN4C_PTRS_PER_PGD;
 
        page_none = SUN4C_PAGE_NONE;
        page_shared = SUN4C_PAGE_SHARED;
        page_copy = SUN4C_PAGE_COPY;
        page_readonly = SUN4C_PAGE_READONLY;
        page_kernel = SUN4C_PAGE_KERNEL;
        pg_iobits = _SUN4C_PAGE_NOCACHE | _SUN4C_PAGE_IO | _SUN4C_PAGE_VALID
            | _SUN4C_PAGE_WRITE | _SUN4C_PAGE_DIRTY;
 
        /* Functions */
#ifndef __SMP__
        flush_cache_all = sun4c_flush_cache_all;
        flush_cache_mm = sun4c_flush_cache_mm;
        flush_cache_range = sun4c_flush_cache_range;
        flush_cache_page = sun4c_flush_cache_page;
 
        flush_tlb_all = sun4c_flush_tlb_all;
        flush_tlb_mm = sun4c_flush_tlb_mm;
        flush_tlb_range = sun4c_flush_tlb_range;
        flush_tlb_page = sun4c_flush_tlb_page;
#else
        local_flush_cache_all = sun4c_flush_cache_all;
        local_flush_cache_mm = sun4c_flush_cache_mm;
        local_flush_cache_range = sun4c_flush_cache_range;
        local_flush_cache_page = sun4c_flush_cache_page;
 
        local_flush_tlb_all = sun4c_flush_tlb_all;
        local_flush_tlb_mm = sun4c_flush_tlb_mm;
        local_flush_tlb_range = sun4c_flush_tlb_range;
        local_flush_tlb_page = sun4c_flush_tlb_page;
 
        flush_cache_all = smp_flush_cache_all;
        flush_cache_mm = smp_flush_cache_mm;
        flush_cache_range = smp_flush_cache_range;
        flush_cache_page = smp_flush_cache_page;
 
        flush_tlb_all = smp_flush_tlb_all;
        flush_tlb_mm = smp_flush_tlb_mm;
        flush_tlb_range = smp_flush_tlb_range;
        flush_tlb_page = smp_flush_tlb_page;
#endif
 
        flush_page_to_ram = sun4c_flush_page_to_ram;
 
        set_pte = sun4c_set_pte;
        switch_to_context = sun4c_switch_to_context;
        pmd_align = sun4c_pmd_align;
        pgdir_align = sun4c_pgdir_align;
        vmalloc_start = sun4c_vmalloc_start;
 
        pte_page = sun4c_pte_page;
        pmd_page = sun4c_pmd_page;
 
        sparc_update_rootmmu_dir = sun4c_update_rootmmu_dir;
 
        pte_none = sun4c_pte_none;
        pte_present = sun4c_pte_present;
        pte_clear = sun4c_pte_clear;
 
        pmd_none = sun4c_pmd_none;
        pmd_bad = sun4c_pmd_bad;
        pmd_present = sun4c_pmd_present;
        pmd_clear = sun4c_pmd_clear;
 
        pgd_none = sun4c_pgd_none;
        pgd_bad = sun4c_pgd_bad;
        pgd_present = sun4c_pgd_present;
        pgd_clear = sun4c_pgd_clear;
 
        mk_pte = sun4c_mk_pte;
        mk_pte_io = sun4c_mk_pte_io;
        pte_modify = sun4c_pte_modify;
        pgd_offset = sun4c_pgd_offset;
        pmd_offset = sun4c_pmd_offset;
        pte_offset = sun4c_pte_offset;
        pte_free_kernel = sun4c_pte_free_kernel;
        pmd_free_kernel = sun4c_pmd_free_kernel;
        pte_alloc_kernel = sun4c_pte_alloc_kernel;
        pmd_alloc_kernel = sun4c_pmd_alloc_kernel;
        pte_free = sun4c_pte_free;
        pte_alloc = sun4c_pte_alloc;
        pmd_free = sun4c_pmd_free;
        pmd_alloc = sun4c_pmd_alloc;
        pgd_free = sun4c_pgd_free;
        pgd_alloc = sun4c_pgd_alloc;
 
        pte_write = sun4c_pte_write;
        pte_dirty = sun4c_pte_dirty;
        pte_young = sun4c_pte_young;
        pte_wrprotect = sun4c_pte_wrprotect;
        pte_mkclean = sun4c_pte_mkclean;
        pte_mkold = sun4c_pte_mkold;
        pte_mkwrite = sun4c_pte_mkwrite;
        pte_mkdirty = sun4c_pte_mkdirty;
        pte_mkyoung = sun4c_pte_mkyoung;
        update_mmu_cache = sun4c_update_mmu_cache;
        mmu_exit_hook = sun4c_exit_hook;
        mmu_flush_hook = sun4c_flush_hook;
        mmu_lockarea = sun4c_lockarea;
        mmu_unlockarea = sun4c_unlockarea;
 
        mmu_get_scsi_one = sun4c_get_scsi_one;
        mmu_get_scsi_sgl = sun4c_get_scsi_sgl;
        mmu_release_scsi_one = sun4c_release_scsi_one;
        mmu_release_scsi_sgl = sun4c_release_scsi_sgl;
 
        mmu_v2p = sun4c_v2p;
        mmu_p2v = sun4c_p2v;
 
        /* Task struct and kernel stack allocating/freeing. */
        alloc_kernel_stack = sun4c_alloc_kernel_stack;
        alloc_task_struct = sun4c_alloc_task_struct;
        free_kernel_stack = sun4c_free_kernel_stack;
        free_task_struct = sun4c_free_task_struct;
 
        quick_kernel_fault = sun4c_quick_kernel_fault;
        mmu_info = sun4c_mmu_info;
 
        /* These should _never_ get called with two level tables. */
        pgd_set = 0;
        pgd_page = 0;
}
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[/] [or1k/] [trunk/] [uclinux/] [uClinux-2.0.x/] [arch/] [sparc/] [mm/] [sun4c.c] - Blame information for rev 1765

Line No.	Rev	Author	Line
1	199	simons	`/* sun4c.c: Doing in software what should be done in hardware.`
2			`*`
3			`* Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu)`
4			`*/`
5
6			`#include <linux/kernel.h>`
7			`#include <linux/mm.h>`
8
9			`#include <asm/page.h>`
10			`#include <asm/pgtable.h>`
11			`#include <asm/vaddrs.h>`
12			`#include <asm/idprom.h>`
13			`#include <asm/machines.h>`
14			`#include <asm/memreg.h>`
15			`#include <asm/processor.h>`
16
17			`extern int num_segmaps, num_contexts;`
18
19			`/* Flushing the cache. */`
20			`struct sun4c_vac_props sun4c_vacinfo;`
21			`static int ctxflushes, segflushes, pageflushes;`
22
23			`/* convert a virtual address to a physical address and vice`
24			`versa. Easy on the 4c */`
25			`static unsigned long sun4c_v2p(unsigned long vaddr)`
26			`{`
27			`return(vaddr - PAGE_OFFSET);`
28			`}`
29
30			`static unsigned long sun4c_p2v(unsigned long vaddr)`
31			`{`
32			`return(vaddr + PAGE_OFFSET);`
33			`}`
34
35
36			`/* Invalidate every sun4c cache line tag. */`
37			`void sun4c_flush_all(void)`
38			`{`
39			`unsigned long begin, end;`
40