target/mips: Move physical addressing code to sysemu/physaddr.c

Declare get_physical_address() with local scope and move it along
with mips_cpu_get_phys_page_debug() to sysemu/physaddr.c new file.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20210428170410.479308-18-f4bug@amsat.org>

2 files changed, 258 insertions, 0 deletions

diff --git a/target/mips/sysemu/meson.build b/target/mips/sysemu/meson.build
index f2a1ff4..925ceea 100644
--- a/target/mips/sysemu/meson.build
+++ b/target/mips/sysemu/meson.build
@@ -2,4 +2,5 @@ mips_softmmu_ss.add(files(
   'addr.c',
   'cp0_timer.c',
   'machine.c',
+  'physaddr.c',
 ))
diff --git a/target/mips/sysemu/physaddr.c b/target/mips/sysemu/physaddr.c
new file mode 100644
index 0000000..1918633
--- /dev/null
+++ b/target/mips/sysemu/physaddr.c
@@ -0,0 +1,257 @@
+/*
+ * MIPS TLB (Translation lookaside buffer) helpers.
+ *
+ *  Copyright (c) 2004-2005 Jocelyn Mayer
+ *
+ * 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 2.1 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/>.
+ */
+#include "qemu/osdep.h"
+#include "cpu.h"
+#include "exec/exec-all.h"
+#include "../internal.h"
+
+static int is_seg_am_mapped(unsigned int am, bool eu, int mmu_idx)
+{
+    /*
+     * Interpret access control mode and mmu_idx.
+     *           AdE?     TLB?
+     *      AM  K S U E  K S U E
+     * UK    0  0 1 1 0  0 - - 0
+     * MK    1  0 1 1 0  1 - - !eu
+     * MSK   2  0 0 1 0  1 1 - !eu
+     * MUSK  3  0 0 0 0  1 1 1 !eu
+     * MUSUK 4  0 0 0 0  0 1 1 0
+     * USK   5  0 0 1 0  0 0 - 0
+     * -     6  - - - -  - - - -
+     * UUSK  7  0 0 0 0  0 0 0 0
+     */
+    int32_t adetlb_mask;
+
+    switch (mmu_idx) {
+    case 3: /* ERL */
+        /* If EU is set, always unmapped */
+        if (eu) {
+            return 0;
+        }
+        /* fall through */
+    case MIPS_HFLAG_KM:
+        /* Never AdE, TLB mapped if AM={1,2,3} */
+        adetlb_mask = 0x70000000;
+        goto check_tlb;
+
+    case MIPS_HFLAG_SM:
+        /* AdE if AM={0,1}, TLB mapped if AM={2,3,4} */
+        adetlb_mask = 0xc0380000;
+        goto check_ade;
+
+    case MIPS_HFLAG_UM:
+        /* AdE if AM={0,1,2,5}, TLB mapped if AM={3,4} */
+        adetlb_mask = 0xe4180000;
+        /* fall through */
+    check_ade:
+        /* does this AM cause AdE in current execution mode */
+        if ((adetlb_mask << am) < 0) {
+            return TLBRET_BADADDR;
+        }
+        adetlb_mask <<= 8;
+        /* fall through */
+    check_tlb:
+        /* is this AM mapped in current execution mode */
+        return ((adetlb_mask << am) < 0);
+    default:
+        assert(0);
+        return TLBRET_BADADDR;
+    };
+}
+
+static int get_seg_physical_address(CPUMIPSState *env, hwaddr *physical,
+                                    int *prot, target_ulong real_address,
+                                    MMUAccessType access_type, int mmu_idx,
+                                    unsigned int am, bool eu,
+                                    target_ulong segmask,
+                                    hwaddr physical_base)
+{
+    int mapped = is_seg_am_mapped(am, eu, mmu_idx);
+
+    if (mapped < 0) {
+        /* is_seg_am_mapped can report TLBRET_BADADDR */
+        return mapped;
+    } else if (mapped) {
+        /* The segment is TLB mapped */
+        return env->tlb->map_address(env, physical, prot, real_address,
+                                     access_type);
+    } else {
+        /* The segment is unmapped */
+        *physical = physical_base | (real_address & segmask);
+        *prot = PAGE_READ | PAGE_WRITE | PAGE_EXEC;
+        return TLBRET_MATCH;
+    }
+}
+
+static int get_segctl_physical_address(CPUMIPSState *env, hwaddr *physical,
+                                       int *prot, target_ulong real_address,
+                                       MMUAccessType access_type, int mmu_idx,
+                                       uint16_t segctl, target_ulong segmask)
+{
+    unsigned int am = (segctl & CP0SC_AM_MASK) >> CP0SC_AM;
+    bool eu = (segctl >> CP0SC_EU) & 1;
+    hwaddr pa = ((hwaddr)segctl & CP0SC_PA_MASK) << 20;
+
+    return get_seg_physical_address(env, physical, prot, real_address,
+                                    access_type, mmu_idx, am, eu, segmask,
+                                    pa & ~(hwaddr)segmask);
+}
+
+int get_physical_address(CPUMIPSState *env, hwaddr *physical,
+                         int *prot, target_ulong real_address,
+                         MMUAccessType access_type, int mmu_idx)
+{
+    /* User mode can only access useg/xuseg */
+#if defined(TARGET_MIPS64)
+    int user_mode = mmu_idx == MIPS_HFLAG_UM;
+    int supervisor_mode = mmu_idx == MIPS_HFLAG_SM;
+    int kernel_mode = !user_mode && !supervisor_mode;
+    int UX = (env->CP0_Status & (1 << CP0St_UX)) != 0;
+    int SX = (env->CP0_Status & (1 << CP0St_SX)) != 0;
+    int KX = (env->CP0_Status & (1 << CP0St_KX)) != 0;
+#endif
+    int ret = TLBRET_MATCH;
+    /* effective address (modified for KVM T&E kernel segments) */
+    target_ulong address = real_address;
+
+    if (mips_um_ksegs_enabled()) {
+        /* KVM T&E adds guest kernel segments in useg */
+        if (real_address >= KVM_KSEG0_BASE) {
+            if (real_address < KVM_KSEG2_BASE) {
+                /* kseg0 */
+                address += KSEG0_BASE - KVM_KSEG0_BASE;
+            } else if (real_address <= USEG_LIMIT) {
+                /* kseg2/3 */
+                address += KSEG2_BASE - KVM_KSEG2_BASE;
+            }
+        }
+    }
+
+    if (address <= USEG_LIMIT) {
+        /* useg */
+        uint16_t segctl;
+
+        if (address >= 0x40000000UL) {
+            segctl = env->CP0_SegCtl2;
+        } else {
+            segctl = env->CP0_SegCtl2 >> 16;
+        }
+        ret = get_segctl_physical_address(env, physical, prot,
+                                          real_address, access_type,
+                                          mmu_idx, segctl, 0x3FFFFFFF);
+#if defined(TARGET_MIPS64)
+    } else if (address < 0x4000000000000000ULL) {
+        /* xuseg */
+        if (UX && address <= (0x3FFFFFFFFFFFFFFFULL & env->SEGMask)) {
+            ret = env->tlb->map_address(env, physical, prot,
+                                        real_address, access_type);
+        } else {
+            ret = TLBRET_BADADDR;
+        }
+    } else if (address < 0x8000000000000000ULL) {
+        /* xsseg */
+        if ((supervisor_mode || kernel_mode) &&
+            SX && address <= (0x7FFFFFFFFFFFFFFFULL & env->SEGMask)) {
+            ret = env->tlb->map_address(env, physical, prot,
+                                        real_address, access_type);
+        } else {
+            ret = TLBRET_BADADDR;
+        }
+    } else if (address < 0xC000000000000000ULL) {
+        /* xkphys */
+        if ((address & 0x07FFFFFFFFFFFFFFULL) <= env->PAMask) {
+            /* KX/SX/UX bit to check for each xkphys EVA access mode */
+            static const uint8_t am_ksux[8] = {
+                [CP0SC_AM_UK]    = (1u << CP0St_KX),
+                [CP0SC_AM_MK]    = (1u << CP0St_KX),
+                [CP0SC_AM_MSK]   = (1u << CP0St_SX),
+                [CP0SC_AM_MUSK]  = (1u << CP0St_UX),
+                [CP0SC_AM_MUSUK] = (1u << CP0St_UX),
+                [CP0SC_AM_USK]   = (1u << CP0St_SX),
+                [6]              = (1u << CP0St_KX),
+                [CP0SC_AM_UUSK]  = (1u << CP0St_UX),
+            };
+            unsigned int am = CP0SC_AM_UK;
+            unsigned int xr = (env->CP0_SegCtl2 & CP0SC2_XR_MASK) >> CP0SC2_XR;
+
+            if (xr & (1 << ((address >> 59) & 0x7))) {
+                am = (env->CP0_SegCtl1 & CP0SC1_XAM_MASK) >> CP0SC1_XAM;
+            }
+            /* Does CP0_Status.KX/SX/UX permit the access mode (am) */
+            if (env->CP0_Status & am_ksux[am]) {
+                ret = get_seg_physical_address(env, physical, prot,
+                                               real_address, access_type,
+                                               mmu_idx, am, false, env->PAMask,
+                                               0);
+            } else {
+                ret = TLBRET_BADADDR;
+            }
+        } else {
+            ret = TLBRET_BADADDR;
+        }
+    } else if (address < 0xFFFFFFFF80000000ULL) {
+        /* xkseg */
+        if (kernel_mode && KX &&
+            address <= (0xFFFFFFFF7FFFFFFFULL & env->SEGMask)) {
+            ret = env->tlb->map_address(env, physical, prot,
+                                        real_address, access_type);
+        } else {
+            ret = TLBRET_BADADDR;
+        }
+#endif
+    } else if (address < KSEG1_BASE) {
+        /* kseg0 */
+        ret = get_segctl_physical_address(env, physical, prot, real_address,
+                                          access_type, mmu_idx,
+                                          env->CP0_SegCtl1 >> 16, 0x1FFFFFFF);
+    } else if (address < KSEG2_BASE) {
+        /* kseg1 */
+        ret = get_segctl_physical_address(env, physical, prot, real_address,
+                                          access_type, mmu_idx,
+                                          env->CP0_SegCtl1, 0x1FFFFFFF);
+    } else if (address < KSEG3_BASE) {
+        /* sseg (kseg2) */
+        ret = get_segctl_physical_address(env, physical, prot, real_address,
+                                          access_type, mmu_idx,
+                                          env->CP0_SegCtl0 >> 16, 0x1FFFFFFF);
+    } else {
+        /*
+         * kseg3
+         * XXX: debug segment is not emulated
+         */
+        ret = get_segctl_physical_address(env, physical, prot, real_address,
+                                          access_type, mmu_idx,
+                                          env->CP0_SegCtl0, 0x1FFFFFFF);
+    }
+    return ret;
+}
+
+hwaddr mips_cpu_get_phys_page_debug(CPUState *cs, vaddr addr)
+{
+    MIPSCPU *cpu = MIPS_CPU(cs);
+    CPUMIPSState *env = &cpu->env;
+    hwaddr phys_addr;
+    int prot;
+
+    if (get_physical_address(env, &phys_addr, &prot, addr, MMU_DATA_LOAD,
+                             cpu_mmu_index(env, false)) != 0) {
+        return -1;
+    }
+    return phys_addr;
+}