Changes in kernel/arch/ppc32/src/mm/tlb.c [655f70b:c99693a] in mainline

File:

• kernel/arch/ppc32/src/mm/tlb.c (modified) (4 diffs)

kernel/arch/ppc32/src/mm/tlb.c

@@ -33 +33 @@
  */
 
+#include <mm/tlb.h>
 #include <arch/mm/tlb.h>
+#include <arch/interrupt.h>
 #include <interrupt.h>
-#include <typedefs.h>
+#include <mm/as.h>
+#include <mm/page.h>
+#include <arch.h>
+#include <print.h>
+#include <macros.h>
+#include <symtab.h>
+
+static unsigned int seed = 42;
+
+/** Try to find PTE for faulting address
+ *
+ * @param as       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, uintptr_t badvaddr, int access,
+    istate_t *istate, int *pfrc)
+{
+        /*
+         * Check if the mapping exists in page tables.
+         */
+        pte_t *pte = page_mapping_find(as, badvaddr, true);
+        if ((pte) && (pte->present)) {
+                /*
+                 * Mapping found in page tables.
+                 * Immediately succeed.
+                 */
+                return pte;
+        } else {
+                /*
+                 * Mapping not found in page tables.
+                 * Resort to higher-level page fault handler.
+                 */
+                int rc = as_page_fault(badvaddr, access, istate);
+                switch (rc) {
+                case AS_PF_OK:
+                        /*
+                         * The higher-level page fault handler succeeded,
+                         * The mapping ought to be in place.
+                         */
+                        pte = page_mapping_find(as, badvaddr, true);
+                        ASSERT((pte) && (pte->present));
+                        *pfrc = 0;
+                        return pte;
+                case AS_PF_DEFER:
+                        *pfrc = rc;
+                        return NULL;
+                case AS_PF_FAULT:
+                        *pfrc = rc;
+                        return NULL;
+                default:
+                        panic("Unexpected rc (%d).", rc);
+                }
+        }
+}
+
+static void pht_refill_fail(uintptr_t badvaddr, istate_t *istate)
+{
+        fault_if_from_uspace(istate, "PHT Refill Exception on %p.",
+            (void *) badvaddr);
+        panic_memtrap(istate, PF_ACCESS_UNKNOWN, badvaddr,
+            "PHT Refill Exception.");
+}
+
+static void pht_insert(const uintptr_t vaddr, const pte_t *pte)
+{
+        uint32_t page = (vaddr >> 12) & 0xffff;
+        uint32_t api = (vaddr >> 22) & 0x3f;
+        
+        uint32_t vsid = sr_get(vaddr);
+        uint32_t sdr1 = sdr1_get();
+        
+        // FIXME: compute size of PHT exactly
+        phte_t *phte = (phte_t *) PA2KA(sdr1 & 0xffff0000);
+        
+        /* Primary hash (xor) */
+        uint32_t h = 0;
+        uint32_t hash = vsid ^ page;
+        uint32_t base = (hash & 0x3ff) << 3;
+        uint32_t i;
+        bool found = false;
+        
+        /* Find 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)
+                    && (phte[base + i].h == 0)) {
+                        found = true;
+                        break;
+                }
+        }
+        
+        if (!found) {
+                /* Find unused PTE in PTEG */
+                for (i = 0; i < 8; i++) {
+                        if (!phte[base + i].v) {
+                                found = true;
+                                break;
+                        }
+                }
+        }
+        
+        if (!found) {
+                /* Secondary hash (not) */
+                uint32_t base2 = (~hash & 0x3ff) << 3;
+                
+                /* Find 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)
+                            && (phte[base2 + i].h == 1)) {
+                                found = true;
+                                base = base2;
+                                h = 1;
+                                break;
+                        }
+                }
+                
+                if (!found) {
+                        /* Find unused PTE in PTEG */
+                        for (i = 0; i < 8; i++) {
+                                if (!phte[base2 + i].v) {
+                                        found = true;
+                                        base = base2;
+                                        h = 1;
+                                        break;
+                                }
+                        }
+                }
+                
+                if (!found)
+                        i = RANDI(seed) % 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 = pte->pfn;
+        phte[base + i].r = 0;
+        phte[base + i].c = 0;
+        phte[base + i].wimg = (pte->page_cache_disable ? WIMG_NO_CACHE : 0);
+        phte[base + i].pp = 2; // FIXME
+}
+
+/** Process Instruction/Data Storage Exception
+ *
+ * @param n      Exception vector number.
+ * @param istate Interrupted register context.
+ *
+ */
+void pht_refill(unsigned int n, istate_t *istate)
+{
+        as_t *as = (AS == NULL) ? AS_KERNEL : AS;
+        uintptr_t badvaddr;
+        
+        if (n == VECTOR_DATA_STORAGE)
+                badvaddr = istate->dar;
+        else
+                badvaddr = istate->pc;
+        
+        int pfrc;
+        pte_t *pte = find_mapping_and_check(as, badvaddr,
+            PF_ACCESS_READ /* FIXME */, istate, &pfrc);
+        
+        if (!pte) {
+                switch (pfrc) {
+                case AS_PF_FAULT:
+                        pht_refill_fail(badvaddr, istate);
+                        return;
+                case AS_PF_DEFER:
+                        /*
+                         * The page fault came during copy_from_uspace()
+                         * or copy_to_uspace().
+                         */
+                        return;
+                default:
+                        panic("Unexpected pfrc (%d).", pfrc);
+                }
+        }
+        
+        /* Record access to PTE */
+        pte->accessed = 1;
+        pht_insert(badvaddr, pte);
+}
 
 void tlb_refill(unsigned int n, istate_t *istate)
@@ -81 +275 @@
 void tlb_invalidate_all(void)
 {
+        uint32_t index;
+        
         asm volatile (
+                "li %[index], 0\n"
                 "sync\n"
-        );
-        
-        for (unsigned int i = 0; i < 0x00040000; i += 0x00001000) {
-                asm volatile (
-                        "tlbie %[i]\n"
-                        :: [i] "r" (i)
-                );
-        }
-        
-        asm volatile (
+                
+                ".rept 64\n"
+                "       tlbie %[index]\n"
+                "       addi %[index], %[index], 0x1000\n"
+                ".endr\n"
+                
                 "eieio\n"
                 "tlbsync\n"
                 "sync\n"
+                : [index] "=r" (index)
         );
 }
@@ -101 +295 @@
 void tlb_invalidate_asid(asid_t asid)
 {
+        uint32_t sdr1 = sdr1_get();
+        
+        // FIXME: compute size of PHT exactly
+        phte_t *phte = (phte_t *) PA2KA(sdr1 & 0xffff0000);
+        
+        size_t i;
+        for (i = 0; i < 8192; i++) {
+                if ((phte[i].v) && (phte[i].vsid >= (asid << 4)) &&
+                    (phte[i].vsid < ((asid << 4) + 16)))
+                        phte[i].v = 0;
+        }
+        
         tlb_invalidate_all();
 }
@@ -106 +312 @@
 void tlb_invalidate_pages(asid_t asid, uintptr_t page, size_t cnt)
 {
+        // TODO
         tlb_invalidate_all();
 }