Changes in kernel/arch/ppc32/src/mm/tlb.c [26aafe8:7e752b2] in mainline

File:

• kernel/arch/ppc32/src/mm/tlb.c (modified) (3 diffs)

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

@@ -44 +44 @@
 #include <symtab.h>
 
-static unsigned int seed = 42;
+static unsigned int seed = 10;
+static unsigned int seed_real
+    __attribute__ ((section("K_UNMAPPED_DATA_START"))) = 42;
 
 /** Try to find PTE for faulting address
@@ -223 +225 @@
                 switch (pfrc) {
                 case AS_PF_FAULT:
-                        page_table_unlock(as, true);
-                        pht_refill_fail(badvaddr, istate);
-                        return;
+                        goto fail;
+                        break;
                 case AS_PF_DEFER:
                         /*
@@ -243 +244 @@
         
         page_table_unlock(as, true);
-}
-
-void tlb_refill(unsigned int n, istate_t *istate)
-{
-        uint32_t tlbmiss;
-        ptehi_t ptehi;
-        ptelo_t ptelo;
-        
-        asm volatile (
-                "mfspr %[tlbmiss], 980\n"
-                "mfspr %[ptehi], 981\n"
-                "mfspr %[ptelo], 982\n"
-                : [tlbmiss] "=r" (tlbmiss),
-                  [ptehi] "=r" (ptehi),
-                  [ptelo] "=r" (ptelo)
-        );
-        
+        return;
+        
+fail:
+        page_table_unlock(as, true);
+        pht_refill_fail(badvaddr, istate);
+}
+
+/** Process Instruction/Data Storage Exception in Real Mode
+ *
+ * @param n      Exception vector number.
+ * @param istate Interrupted register context.
+ *
+ */
+bool pht_refill_real(unsigned int n, istate_t *istate)
+{
+        uintptr_t badvaddr;
+        
+        if (n == VECTOR_DATA_STORAGE)
+                badvaddr = istate->dar;
+        else
+                badvaddr = istate->pc;
+        
+        uint32_t physmem = physmem_top();
+        
+        if ((badvaddr < PA2KA(0)) || (badvaddr >= PA2KA(physmem)))
+                return false;
+        
+        uint32_t page = (badvaddr >> 12) & 0xffff;
+        uint32_t api = (badvaddr >> 22) & 0x3f;
+        
+        uint32_t vsid = sr_get(badvaddr);
+        uint32_t sdr1 = sdr1_get();
+        
+        // FIXME: compute size of PHT exactly
+        phte_t *phte_real = (phte_t *) (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_real[base + i].v)
+                    && (phte_real[base + i].vsid == vsid)
+                    && (phte_real[base + i].api == api)
+                    && (phte_real[base + i].h == 0)) {
+                        found = true;
+                        break;
+                }
+        }
+        
+        if (!found) {
+                /* Find unused PTE in PTEG */
+                for (i = 0; i < 8; i++) {
+                        if (!phte_real[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_real[base2 + i].v)
+                            && (phte_real[base2 + i].vsid == vsid)
+                            && (phte_real[base2 + i].api == api)
+                            && (phte_real[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_real[base2 + i].v) {
+                                        found = true;
+                                        base = base2;
+                                        h = 1;
+                                        break;
+                                }
+                        }
+                }
+                
+                if (!found) {
+                        /* Use secondary hash to avoid collisions
+                           with usual PHT refill handler. */
+                        i = RANDI(seed_real) % 8;
+                        base = base2;
+                        h = 1;
+                }
+        }
+        
+        phte_real[base + i].v = 1;
+        phte_real[base + i].vsid = vsid;
+        phte_real[base + i].h = h;
+        phte_real[base + i].api = api;
+        phte_real[base + i].rpn = KA2PA(badvaddr) >> 12;
+        phte_real[base + i].r = 0;
+        phte_real[base + i].c = 0;
+        phte_real[base + i].wimg = 0;
+        phte_real[base + i].pp = 2; // FIXME
+        
+        return true;
+}
+
+/** Process ITLB/DTLB Miss Exception in Real Mode
+ *
+ *
+ */
+void tlb_refill_real(unsigned int n, uint32_t tlbmiss, ptehi_t ptehi,
+    ptelo_t ptelo, istate_t *istate)
+{
         uint32_t badvaddr = tlbmiss & 0xfffffffc;
         uint32_t physmem = physmem_top();