1 files changed, 363 insertions, 0 deletions

diff --git a/qemu/target-cris/mmu.c b/qemu/target-cris/mmu.c
new file mode 100644
index 000000000..1c95a415f
--- /dev/null
+++ b/qemu/target-cris/mmu.c
@@ -0,0 +1,363 @@
+/*
+ *  CRIS mmu emulation.
+ *
+ *  Copyright (c) 2007 AXIS Communications AB
+ *  Written by Edgar E. Iglesias.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef CONFIG_USER_ONLY
+
+#include "cpu.h"
+#include "mmu.h"
+
+#ifdef DEBUG
+#define D(x) x
+#define D_LOG(...) qemu_log(__VA_ARGS__)
+#else
+#define D(x) do { } while (0)
+#define D_LOG(...) do { } while (0)
+#endif
+
+void cris_mmu_init(CPUCRISState *env)
+{
+	env->mmu_rand_lfsr = 0xcccc;
+}
+
+#define SR_POLYNOM 0x8805
+static inline unsigned int compute_polynom(unsigned int sr)
+{
+	unsigned int i;
+	unsigned int f;
+
+	f = 0;
+	for (i = 0; i < 16; i++)
+		f += ((SR_POLYNOM >> i) & 1) & ((sr >> i) & 1);
+
+	return f;
+}
+
+static void cris_mmu_update_rand_lfsr(CPUCRISState *env)
+{
+	unsigned int f;
+
+	/* Update lfsr at every fault.  */
+	f = compute_polynom(env->mmu_rand_lfsr);
+	env->mmu_rand_lfsr >>= 1;
+	env->mmu_rand_lfsr |= (f << 15);
+	env->mmu_rand_lfsr &= 0xffff;
+}
+
+static inline int cris_mmu_enabled(uint32_t rw_gc_cfg)
+{
+	return (rw_gc_cfg & 12) != 0;
+}
+
+static inline int cris_mmu_segmented_addr(int seg, uint32_t rw_mm_cfg)
+{
+	return (1 << seg) & rw_mm_cfg;
+}
+
+static uint32_t cris_mmu_translate_seg(CPUCRISState *env, int seg)
+{
+	uint32_t base;
+	int i;
+
+	if (seg < 8)
+		base = env->sregs[SFR_RW_MM_KBASE_LO];
+	else
+		base = env->sregs[SFR_RW_MM_KBASE_HI];
+
+	i = seg & 7;
+	base >>= i * 4;
+	base &= 15;
+
+	base <<= 28;
+	return base;
+}
+/* Used by the tlb decoder.  */
+#define EXTRACT_FIELD(src, start, end) \
+	    (((src) >> start) & ((1 << (end - start + 1)) - 1))
+
+static inline void set_field(uint32_t *dst, unsigned int val, 
+			     unsigned int offset, unsigned int width)
+{
+	uint32_t mask;
+
+	mask = (1 << width) - 1;
+	mask <<= offset;
+	val <<= offset;
+
+	val &= mask;
+	*dst &= ~(mask);
+	*dst |= val;
+}
+
+#ifdef DEBUG
+static void dump_tlb(CPUCRISState *env, int mmu)
+{
+	int set;
+	int idx;
+	uint32_t hi, lo, tlb_vpn, tlb_pfn;
+
+	for (set = 0; set < 4; set++) {
+		for (idx = 0; idx < 16; idx++) {
+			lo = env->tlbsets[mmu][set][idx].lo;
+			hi = env->tlbsets[mmu][set][idx].hi;
+			tlb_vpn = EXTRACT_FIELD(hi, 13, 31);
+			tlb_pfn = EXTRACT_FIELD(lo, 13, 31);
+
+			printf ("TLB: [%d][%d] hi=%x lo=%x v=%x p=%x\n", 
+					set, idx, hi, lo, tlb_vpn, tlb_pfn);
+		}
+	}
+}
+#endif
+
+/* rw 0 = read, 1 = write, 2 = exec.  */
+static int cris_mmu_translate_page(struct cris_mmu_result *res,
+				   CPUCRISState *env, uint32_t vaddr,
+				   int rw, int usermode, int debug)
+{
+	unsigned int vpage;
+	unsigned int idx;
+	uint32_t pid, lo, hi;
+	uint32_t tlb_vpn, tlb_pfn = 0;
+	int tlb_pid, tlb_g, tlb_v, tlb_k, tlb_w, tlb_x;
+	int cfg_v, cfg_k, cfg_w, cfg_x;	
+	int set, match = 0;
+	uint32_t r_cause;
+	uint32_t r_cfg;
+	int rwcause;
+	int mmu = 1; /* Data mmu is default.  */
+	int vect_base;
+
+	r_cause = env->sregs[SFR_R_MM_CAUSE];
+	r_cfg = env->sregs[SFR_RW_MM_CFG];
+	pid = env->pregs[PR_PID] & 0xff;
+
+	switch (rw) {
+		case 2: rwcause = CRIS_MMU_ERR_EXEC; mmu = 0; break;
+		case 1: rwcause = CRIS_MMU_ERR_WRITE; break;
+		default:
+		case 0: rwcause = CRIS_MMU_ERR_READ; break;
+	}
+
+	/* I exception vectors 4 - 7, D 8 - 11.  */
+	vect_base = (mmu + 1) * 4;
+
+	vpage = vaddr >> 13;
+
+	/* We know the index which to check on each set.
+	   Scan both I and D.  */
+#if 0
+	for (set = 0; set < 4; set++) {
+		for (idx = 0; idx < 16; idx++) {
+			lo = env->tlbsets[mmu][set][idx].lo;
+			hi = env->tlbsets[mmu][set][idx].hi;
+			tlb_vpn = EXTRACT_FIELD(hi, 13, 31);
+			tlb_pfn = EXTRACT_FIELD(lo, 13, 31);
+
+			printf ("TLB: [%d][%d] hi=%x lo=%x v=%x p=%x\n", 
+					set, idx, hi, lo, tlb_vpn, tlb_pfn);
+		}
+	}
+#endif
+
+	idx = vpage & 15;
+	for (set = 0; set < 4; set++)
+	{
+		lo = env->tlbsets[mmu][set][idx].lo;
+		hi = env->tlbsets[mmu][set][idx].hi;
+
+		tlb_vpn = hi >> 13;
+		tlb_pid = EXTRACT_FIELD(hi, 0, 7);
+		tlb_g  = EXTRACT_FIELD(lo, 4, 4);
+
+		D_LOG("TLB[%d][%d][%d] v=%x vpage=%x lo=%x hi=%x\n", 
+			 mmu, set, idx, tlb_vpn, vpage, lo, hi);
+		if ((tlb_g || (tlb_pid == pid))
+		    && tlb_vpn == vpage) {
+			match = 1;
+			break;
+		}
+	}
+
+	res->bf_vec = vect_base;
+	if (match) {
+		cfg_w  = EXTRACT_FIELD(r_cfg, 19, 19);
+		cfg_k  = EXTRACT_FIELD(r_cfg, 18, 18);
+		cfg_x  = EXTRACT_FIELD(r_cfg, 17, 17);
+		cfg_v  = EXTRACT_FIELD(r_cfg, 16, 16);
+
+		tlb_pfn = EXTRACT_FIELD(lo, 13, 31);
+		tlb_v = EXTRACT_FIELD(lo, 3, 3);
+		tlb_k = EXTRACT_FIELD(lo, 2, 2);
+		tlb_w = EXTRACT_FIELD(lo, 1, 1);
+		tlb_x = EXTRACT_FIELD(lo, 0, 0);
+
+		/*
+		set_exception_vector(0x04, i_mmu_refill);
+		set_exception_vector(0x05, i_mmu_invalid);
+		set_exception_vector(0x06, i_mmu_access);
+		set_exception_vector(0x07, i_mmu_execute);
+		set_exception_vector(0x08, d_mmu_refill);
+		set_exception_vector(0x09, d_mmu_invalid);
+		set_exception_vector(0x0a, d_mmu_access);
+		set_exception_vector(0x0b, d_mmu_write);
+		*/
+		if (cfg_k && tlb_k && usermode) {
+			D(printf ("tlb: kernel protected %x lo=%x pc=%x\n", 
+				  vaddr, lo, env->pc));
+			match = 0;
+			res->bf_vec = vect_base + 2;
+		} else if (rw == 1 && cfg_w && !tlb_w) {
+			D(printf ("tlb: write protected %x lo=%x pc=%x\n", 
+				  vaddr, lo, env->pc));
+			match = 0;
+			/* write accesses never go through the I mmu.  */
+			res->bf_vec = vect_base + 3;
+		} else if (rw == 2 && cfg_x && !tlb_x) {
+			D(printf ("tlb: exec protected %x lo=%x pc=%x\n", 
+				 vaddr, lo, env->pc));
+			match = 0;
+			res->bf_vec = vect_base + 3;
+		} else if (cfg_v && !tlb_v) {
+			D(printf ("tlb: invalid %x\n", vaddr));
+			match = 0;
+			res->bf_vec = vect_base + 1;
+		}
+
+		res->prot = 0;
+		if (match) {
+			res->prot |= PAGE_READ;
+			if (tlb_w)
+				res->prot |= PAGE_WRITE;
+			if (mmu == 0 && (cfg_x || tlb_x))
+				res->prot |= PAGE_EXEC;
+		}
+		else
+			D(dump_tlb(env, mmu));
+	} else {
+		/* If refill, provide a randomized set.  */
+		set = env->mmu_rand_lfsr & 3;
+	}
+
+	if (!match && !debug) {
+		cris_mmu_update_rand_lfsr(env);
+
+		/* Compute index.  */
+		idx = vpage & 15;
+
+		/* Update RW_MM_TLB_SEL.  */
+		env->sregs[SFR_RW_MM_TLB_SEL] = 0;
+		set_field(&env->sregs[SFR_RW_MM_TLB_SEL], idx, 0, 4);
+		set_field(&env->sregs[SFR_RW_MM_TLB_SEL], set, 4, 2);
+
+		/* Update RW_MM_CAUSE.  */
+		set_field(&r_cause, rwcause, 8, 2);
+		set_field(&r_cause, vpage, 13, 19);
+		set_field(&r_cause, pid, 0, 8);
+		env->sregs[SFR_R_MM_CAUSE] = r_cause;
+		D(printf("refill vaddr=%x pc=%x\n", vaddr, env->pc));
+	}
+
+	D(printf ("%s rw=%d mtch=%d pc=%x va=%x vpn=%x tlbvpn=%x pfn=%x pid=%x"
+		  " %x cause=%x sel=%x sp=%x %x %x\n",
+		  __func__, rw, match, env->pc,
+		  vaddr, vpage,
+		  tlb_vpn, tlb_pfn, tlb_pid, 
+		  pid,
+		  r_cause,
+		  env->sregs[SFR_RW_MM_TLB_SEL],
+		  env->regs[R_SP], env->pregs[PR_USP], env->ksp));
+
+	res->phy = tlb_pfn << TARGET_PAGE_BITS;
+	return !match;
+}
+
+void cris_mmu_flush_pid(CPUCRISState *env, uint32_t pid)
+{
+    CRISCPU *cpu = cris_env_get_cpu(env);
+	target_ulong vaddr;
+	unsigned int idx;
+	uint32_t lo, hi;
+	uint32_t tlb_vpn;
+	int tlb_pid, tlb_g, tlb_v;
+	unsigned int set;
+	unsigned int mmu;
+
+	pid &= 0xff;
+	for (mmu = 0; mmu < 2; mmu++) {
+		for (set = 0; set < 4; set++)
+		{
+			for (idx = 0; idx < 16; idx++) {
+				lo = env->tlbsets[mmu][set][idx].lo;
+				hi = env->tlbsets[mmu][set][idx].hi;
+				
+				tlb_vpn = EXTRACT_FIELD(hi, 13, 31);
+				tlb_pid = EXTRACT_FIELD(hi, 0, 7);
+				tlb_g  = EXTRACT_FIELD(lo, 4, 4);
+				tlb_v = EXTRACT_FIELD(lo, 3, 3);
+
+				if (tlb_v && !tlb_g && (tlb_pid == pid)) {
+					vaddr = tlb_vpn << TARGET_PAGE_BITS;
+					D_LOG("flush pid=%x vaddr=%x\n", 
+						  pid, vaddr);
+                    tlb_flush_page(CPU(cpu), vaddr);
+				}
+			}
+		}
+	}
+}
+
+int cris_mmu_translate(struct cris_mmu_result *res,
+		       CPUCRISState *env, uint32_t vaddr,
+		       int rw, int mmu_idx, int debug)
+{
+	int seg;
+	int miss = 0;
+	int is_user = mmu_idx == MMU_USER_IDX;
+	uint32_t old_srs;
+
+	old_srs= env->pregs[PR_SRS];
+
+	/* rw == 2 means exec, map the access to the insn mmu.  */
+	env->pregs[PR_SRS] = rw == 2 ? 1 : 2;
+
+	if (!cris_mmu_enabled(env->sregs[SFR_RW_GC_CFG])) {
+		res->phy = vaddr;
+		res->prot = PAGE_BITS;
+		goto done;
+	}
+
+	seg = vaddr >> 28;
+	if (!is_user && cris_mmu_segmented_addr(seg, env->sregs[SFR_RW_MM_CFG]))
+	{
+		uint32_t base;
+
+		miss = 0;
+		base = cris_mmu_translate_seg(env, seg);
+                res->phy = base | (0x0fffffff & vaddr);
+		res->prot = PAGE_BITS;
+	} else {
+		miss = cris_mmu_translate_page(res, env, vaddr, rw,
+					       is_user, debug);
+	}
+  done:
+	env->pregs[PR_SRS] = old_srs;
+	return miss;
+}
+#endif