WebSVN – HelenOS – Diff – /trunk/kernel/arch/ppc32/src/mm/tlb.c

 /*
  * Copyright (C) 2006 Martin Decky
  * All rights reserved.
+ *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
+ *
  * - Redistributions of source code must retain the above copyright
  *   notice, this list of conditions and the following disclaimer.
  * - Redistributions in binary form must reproduce the above copyright
  *   notice, this list of conditions and the following disclaimer in the
  *   documentation and/or other materials provided with the distribution.
  * - The name of the author may not be used to endorse or promote products
  *   derived from this software without specific prior written permission.
+ *
  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
- /** @addtogroup ppc32mm
+/** @addtogroup ppc32mm
  * @{
  */
 /** @file
  */
 #include <mm/tlb.h>
+#include <arch/mm/tlb.h>
+#include <arch/interrupt.h>
+#include <mm/as.h>
+#include <arch.h>
+#include <print.h>
+#include <symtab.h>
-/** Initialize Page Hash Table.
+/** Try to find PTE for faulting address
+ *
- * Setup the Page Hash Table with no entries.
+ * Try to find PTE for faulting address.
+ * The as->lock must be held on entry to this function
+ * if lock is true.
+ *
+ * @param as       Address space.
+ * @param lock     Lock/unlock the address space.
+ * @param badvaddr Faulting virtual address.
+ * @param access   Access mode that caused the fault.
+ * @param istate   Pointer to interrupted state.
+ * @param pfrc     Pointer to variable where as_page_fault() return code will be stored.
+ * @return         PTE on success, NULL otherwise.
+ *
  */
+static pte_t *find_mapping_and_check(as_t *as, bool lock, __address badvaddr, int access, istate_t *istate, int *pfrc)
+{
+    /*
+     * Check if the mapping exists in page tables.
+     */
+    pte_t *pte = page_mapping_find(as, badvaddr);
+    if ((pte) && (pte->p)) {
+        /*
+         * Mapping found in page tables.
+         * Immediately succeed.
+         */
+        return pte;
+    } else {
+        int rc;
+        /*
+         * Mapping not found in page tables.
+         * Resort to higher-level page fault handler.
+         */
+        page_table_unlock(as, lock);
+        switch (rc = as_page_fault(badvaddr, access, istate)) {
+            case AS_PF_OK:
+                /*
+                 * The higher-level page fault handler succeeded,
+                 * The mapping ought to be in place.
+                 */
+                page_table_lock(as, lock);
+                pte = page_mapping_find(as, badvaddr);
+                ASSERT((pte) && (pte->p));
+                return pte;
+            case AS_PF_DEFER:
+                page_table_lock(as, lock);
+                *pfrc = rc;
+                return NULL;
+            case AS_PF_FAULT:
+                page_table_lock(as, lock);
+                printf("Page fault.\n");
+                *pfrc = rc;
+                return NULL;
+            default:
+                panic("unexpected rc (%d)\n", rc);
+        }
+    }
+}
+static void pht_refill_fail(__address badvaddr, istate_t *istate)
+{
+    char *symbol = "";
+    char *sym2 = "";
+    char *s = get_symtab_entry(istate->pc);
+    if (s)
+        symbol = s;
+    s = get_symtab_entry(istate->lr);
+    if (s)
+        sym2 = s;
+    panic("%p: PHT Refill Exception at %p (%s<-%s)\n", badvaddr, istate->pc, symbol, sym2);
+}
+static void pht_insert(const __address vaddr, const pfn_t pfn)
+{
+    __u32 page = (vaddr >> 12) & 0xffff;
+    __u32 api = (vaddr >> 22) & 0x3f;
+    __u32 vsid;
+    asm volatile (
+        "mfsrin %0, %1\n"
+        : "=r" (vsid)
+        : "r" (vaddr)
+    );
+    __u32 sdr1;
+    asm volatile (
+        "mfsdr1 %0\n"
+        : "=r" (sdr1)
+    );
+    phte_t *phte = (phte_t *) PA2KA(sdr1 & 0xffff0000);
+    /* Primary hash (xor) */
+    __u32 h = 0;
+    __u32 hash = vsid ^ page;
+    __u32 base = (hash & 0x3ff) << 3;
+    __u32 i;
+    bool found = false;
+    /* Find unused or colliding
+       PTE in PTEG */
+    for (i = 0; i < 8; i++) {
+        if ((!phte[base + i].v) || ((phte[base + i].vsid == vsid) && (phte[base + i].api == api))) {
+            found = true;
+            break;
+        }
+    }
+    if (!found) {
+        /* Secondary hash (not) */
+        __u32 base2 = (~hash & 0x3ff) << 3;
+        /* Find unused or colliding
+           PTE in PTEG */
+        for (i = 0; i < 8; i++) {
+            if ((!phte[base2 + i].v) || ((phte[base2 + i].vsid == vsid) && (phte[base2 + i].api == api))) {
+                found = true;
+                base = base2;
+                h = 1;
+                break;
+            }
+        }
+        if (!found) {
+            // TODO: A/C precedence groups
+            i = page % 8;
+        }
+    }
+    phte[base + i].v = 1;
+    phte[base + i].vsid = vsid;
+    phte[base + i].h = h;
+    phte[base + i].api = api;
+    phte[base + i].rpn = pfn;
+    phte[base + i].r = 0;
+    phte[base + i].c = 0;
+    phte[base + i].pp = 2; // FIXME
+}
+static void pht_real_insert(const __address vaddr, const pfn_t pfn)
+{
+    __u32 page = (vaddr >> 12) & 0xffff;
+    __u32 api = (vaddr >> 22) & 0x3f;
+    __u32 vsid;
+    asm volatile (
+        "mfsrin %0, %1\n"
+        : "=r" (vsid)
+        : "r" (vaddr)
+    );
+    __u32 sdr1;
+    asm volatile (
+        "mfsdr1 %0\n"
+        : "=r" (sdr1)
+    );
+    phte_t *phte_physical = (phte_t *) (sdr1 & 0xffff0000);
+    /* Primary hash (xor) */
+    __u32 h = 0;
+    __u32 hash = vsid ^ page;
+    __u32 base = (hash & 0x3ff) << 3;
+    __u32 i;
+    bool found = false;
+    /* Find unused or colliding
+       PTE in PTEG */
+    for (i = 0; i < 8; i++) {
+        if ((!phte_physical[base + i].v) || ((phte_physical[base + i].vsid == vsid) && (phte_physical[base + i].api == api))) {
+            found = true;
+            break;
+        }
+    }
+    if (!found) {
+        /* Secondary hash (not) */
+        __u32 base2 = (~hash & 0x3ff) << 3;
+        /* Find unused or colliding
+           PTE in PTEG */
+        for (i = 0; i < 8; i++) {
+            if ((!phte_physical[base2 + i].v) || ((phte_physical[base2 + i].vsid == vsid) && (phte_physical[base2 + i].api == api))) {
+                found = true;
+                base = base2;
+                h = 1;
+                break;
+            }
+        }
+        if (!found) {
+            // TODO: A/C precedence groups
+            i = page % 8;
+        }
+    }
+    phte_physical[base + i].v = 1;
+    phte_physical[base + i].vsid = vsid;
+    phte_physical[base + i].h = h;
+    phte_physical[base + i].api = api;
+    phte_physical[base + i].rpn = pfn;
+    phte_physical[base + i].r = 0;
+    phte_physical[base + i].c = 0;
+    phte_physical[base + i].pp = 2; // FIXME
+}
+/** Process Instruction/Data Storage Interrupt
+ *
+ * @param n Interrupt vector number.
+ * @param istate Interrupted register context.
+ *
+ */
+void pht_refill(int n, istate_t *istate)
+{
+    __address badvaddr;
+    pte_t *pte;
+    int pfrc;
+    as_t *as;
+    bool lock;
+    if (AS == NULL) {
+        as = AS_KERNEL;
+        lock = false;
+    } else {
+        as = AS;
+        lock = true;
+    }
+    if (n == VECTOR_DATA_STORAGE) {
+        asm volatile (
+            "mfdar %0\n"
+            : "=r" (badvaddr)
+        );
+    } else
+        badvaddr = istate->pc;
+    page_table_lock(as, lock);
+    pte = find_mapping_and_check(as, lock, badvaddr, PF_ACCESS_READ /* FIXME */, istate, &pfrc);
+    if (!pte) {
+        switch (pfrc) {
+            case AS_PF_FAULT:
+                goto fail;
+                break;
+            case AS_PF_DEFER:
+                /*
+                 * The page fault came during copy_from_uspace()
+                 * or copy_to_uspace().
+                 */
+                page_table_unlock(as, lock);
+                return;
+            default:
+                panic("Unexpected pfrc (%d)\n", pfrc);
+        }
+    }
+    pte->a = 1; /* Record access to PTE */
+    pht_insert(badvaddr, pte->pfn);
+    page_table_unlock(as, lock);
+    return;
+fail:
+    page_table_unlock(as, lock);
+    pht_refill_fail(badvaddr, istate);
+}
+/** Process Instruction/Data Storage Interrupt in Real Mode
+ *
+ * @param n Interrupt vector number.
+ * @param istate Interrupted register context.
+ *
+ */
+bool pht_real_refill(int n, istate_t *istate)
+{
+    __address badvaddr;
+    if (n == VECTOR_DATA_STORAGE) {
+        asm volatile (
+            "mfdar %0\n"
+            : "=r" (badvaddr)
+        );
+    } else
+        badvaddr = istate->pc;
+    __u32 physmem;
+    asm volatile (
+        "mfsprg3 %0\n"
+        : "=r" (physmem)
+    );
+    if ((badvaddr >= PA2KA(0)) && (badvaddr < PA2KA(physmem))) {
+        pht_real_insert(badvaddr, KA2PA(badvaddr) >> 12);
+        return true;
+    }
+    return false;
+}
 void tlb_arch_init(void)
+{
     tlb_invalidate_all();
+}
 void tlb_invalidate_all(void)
+{
     asm volatile (
         "tlbia\n"
         "tlbsync\n"
     );
+}
-/** Invalidate all entries in TLB that belong to specified address space.
- *
- * @param asid This parameter is ignored as the architecture doesn't support it.
- */
 void tlb_invalidate_asid(asid_t asid)
+{
+    // TODO
     tlb_invalidate_all();
+}
-/** Invalidate TLB entries for specified page range belonging to specified address space.
- *
- * @param asid This parameter is ignored as the architecture doesn't support it.
- * @param page Address of the first page whose entry is to be invalidated.
- * @param cnt Number of entries to invalidate.
- */
 void tlb_invalidate_pages(asid_t asid, __address page, count_t cnt)
+{
+    // TODO
     tlb_invalidate_all();
+}
-/** Print contents of Page Hash Table. */
 void tlb_print(void)
+{
+    // TODO
+}
- /** @}
+/** @}
  */

Subversion Repositories HelenOS

(root)/trunk/kernel/arch/ppc32/src/mm/tlb.c @ 3594 – Rev 1702 → 1730