[Stable-9.2.4 07/34] target/mips: Simplify and fix update_pagemask

[Michael Tokarev]

From: Richard Henderson <richard.hender...@linaro.org>

When update_pagemask was split from helper_mtc0_pagemask,
we failed to actually write to the new parameter but continue
to write to env->CP0_PageMask.  Thus the use within
page_table_walk_refill modifies cpu state and not the local
variable as expected.

Simplify by renaming to compute_pagemask and returning the
value directly.  No need for either env or pointer return.

Fixes: 074cfcb4dae ("target/mips: Implement hardware page table walker for 
MIPS32")
Signed-off-by: Richard Henderson <richard.hender...@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <phi...@linaro.org>
Message-ID: <20250328175526.368121-4-richard.hender...@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <phi...@linaro.org>
Cc: qemu-sta...@nongnu.org
(cherry picked from commit 256ba7715b109c080c0c77a3923df9e69736ba17)
Signed-off-by: Michael Tokarev <m...@tls.msk.ru>

diff --git a/target/mips/tcg/sysemu/cp0_helper.c 
b/target/mips/tcg/sysemu/cp0_helper.c
index 4796638126..3bfb6edbd0 100644
--- a/target/mips/tcg/sysemu/cp0_helper.c
+++ b/target/mips/tcg/sysemu/cp0_helper.c
@@ -864,24 +864,24 @@ void helper_mtc0_memorymapid(CPUMIPSState *env, 
target_ulong arg1)
     }
 }
 
-void update_pagemask(CPUMIPSState *env, target_ulong arg1, int32_t *pagemask)
+uint32_t compute_pagemask(uint32_t val)
 {
     /* Don't care MASKX as we don't support 1KB page */
-    uint32_t mask = extract32((uint32_t)arg1, CP0PM_MASK, 16);
+    uint32_t mask = extract32(val, CP0PM_MASK, 16);
     int maskbits = cto32(mask);
 
     /* Ensure no more set bit after first zero, and maskbits even. */
     if ((mask >> maskbits) == 0 && maskbits % 2 == 0) {
-        env->CP0_PageMask = mask << CP0PM_MASK;
+        return mask << CP0PM_MASK;
     } else {
         /* When invalid, set to default target page size. */
-        env->CP0_PageMask = 0;
+        return 0;
     }
 }
 
 void helper_mtc0_pagemask(CPUMIPSState *env, target_ulong arg1)
 {
-    update_pagemask(env, arg1, &env->CP0_PageMask);
+    env->CP0_PageMask = compute_pagemask(arg1);
 }
 
 void helper_mtc0_pagegrain(CPUMIPSState *env, target_ulong arg1)
diff --git a/target/mips/tcg/sysemu/tlb_helper.c 
b/target/mips/tcg/sysemu/tlb_helper.c
index 62a3a86d80..56b1e8a36e 100644
--- a/target/mips/tcg/sysemu/tlb_helper.c
+++ b/target/mips/tcg/sysemu/tlb_helper.c
@@ -875,7 +875,7 @@ refill:
         }
     }
     pw_pagemask = m >> TARGET_PAGE_BITS;
-    update_pagemask(env, pw_pagemask << CP0PM_MASK, &pw_pagemask);
+    pw_pagemask = compute_pagemask(pw_pagemask << CP0PM_MASK);
     pw_entryhi = (address & ~0x1fff) | (env->CP0_EntryHi & 0xFF);
     {
         target_ulong tmp_entryhi = env->CP0_EntryHi;
diff --git a/target/mips/tcg/tcg-internal.h b/target/mips/tcg/tcg-internal.h
index aef032c48d..be398665e6 100644
--- a/target/mips/tcg/tcg-internal.h
+++ b/target/mips/tcg/tcg-internal.h
@@ -45,7 +45,7 @@ bool mips_cpu_exec_interrupt(CPUState *cpu, int int_req);
 
 void mmu_init(CPUMIPSState *env, const mips_def_t *def);
 
-void update_pagemask(CPUMIPSState *env, target_ulong arg1, int32_t *pagemask);
+uint32_t compute_pagemask(uint32_t val);
 
 void r4k_invalidate_tlb(CPUMIPSState *env, int idx, int use_extra);
 uint32_t cpu_mips_get_random(CPUMIPSState *env);
-- 
2.39.5