Re: [PATCH v2 24/28] target/ppc/mmu_common.c: Remove BookE handling from get_physical_address_wtlb()

[BALATON Zoltan]

On Tue, 7 May 2024, Nicholas Piggin wrote:
On Thu May 2, 2024 at 9:43 AM AEST, BALATON Zoltan wrote:
This function is no longer called for BookE MMU model so remove parts
related to it. This has uncovered a few may be used uninitialised
warnings that are also fixed.
Signed-off-by: BALATON Zoltan <bala...@eik.bme.hu>
---
 target/ppc/mmu_common.c | 25 +++++--------------------
 1 file changed, 5 insertions(+), 20 deletions(-)

diff --git a/target/ppc/mmu_common.c b/target/ppc/mmu_common.c
index a1f98f8de4..d61c41d8c9 100644
--- a/target/ppc/mmu_common.c
+++ b/target/ppc/mmu_common.c
@@ -684,12 +684,10 @@ static int mmubooke_get_physical_address(CPUPPCState 
*env, mmu_ctx_t *ctx,
         ret = mmubooke_check_tlb(env, tlb, &raddr, &ctx->prot, address,
                                  access_type, i);
         if (ret != -1) {
-            if (ret >= 0) {
-                ctx->raddr = raddr;
-            }
             break;
         }
     }
+    ctx->raddr = raddr;
     qemu_log_mask(CPU_LOG_MMU,
                   "%s: access %s " TARGET_FMT_lx " => " HWADDR_FMT_plx
                   " %d %d\n", __func__, ret < 0 ? "refused" : "granted",
@@ -897,9 +895,6 @@ static int mmubooke206_get_physical_address(CPUPPCState 
*env, mmu_ctx_t *ctx,
             ret = mmubooke206_check_tlb(env, tlb, &raddr, &ctx->prot, address,
                                         access_type, mmu_idx);
             if (ret != -1) {
-                if (ret >= 0) {
-                    ctx->raddr = raddr;
-                }
                 goto found_tlb;
             }
         }
@@ -907,6 +902,7 @@ static int mmubooke206_get_physical_address(CPUPPCState 
*env, mmu_ctx_t *ctx,

 found_tlb:

+    ctx->raddr = raddr;

Not sure about the uninitialized warnings here either, caller probably
should not be using ctx->raddr unless we returned 0...

     qemu_log_mask(CPU_LOG_MMU, "%s: access %s " TARGET_FMT_lx " => "
                   HWADDR_FMT_plx " %d %d\n", __func__,
                   ret < 0 ? "refused" : "granted", address, raddr,
@@ -1163,20 +1159,9 @@ static int get_physical_address_wtlb(CPUPPCState *env, 
mmu_ctx_t *ctx,
                                      MMUAccessType access_type, int type,
                                      int mmu_idx)
 {
-    bool real_mode;
-
-    if (env->mmu_model == POWERPC_MMU_BOOKE) {
-        return mmubooke_get_physical_address(env, ctx, eaddr, access_type);
-    } else if (env->mmu_model == POWERPC_MMU_BOOKE206) {
-        return mmubooke206_get_physical_address(env, ctx, eaddr, access_type,
-                                                mmu_idx);
-    }

This could just go in the previous patch when you split booke xlate?

Removing this uncovers the warnings so I keep it here to separate it from 
the previous change. I gave up on trying to resolve these warnings and 
untangle the embedded functions from mmu_ctx_t which would be needed to 
move these booke functions out from this file. The other problem is that 
these booke get_physical_address functions and mmu40x_get_physical_address 
all use ppcemb_tlb_check which then needs to be in the same file and 
static to be inlined and not run too slow but 40x is still in jumbo_xlate 
so I just leave it for now and may return to it later or let somebody else 
continue from here. I think this series moves forward enough for now and I 
don't have more time now.

-
-    real_mode = (type == ACCESS_CODE) ? !FIELD_EX64(env->msr, MSR, IR)
-                                      : !FIELD_EX64(env->msr, MSR, DR);
-    if (real_mode && (env->mmu_model == POWERPC_MMU_SOFT_6xx ||
-                      env->mmu_model == POWERPC_MMU_SOFT_4xx ||
-                      env->mmu_model == POWERPC_MMU_REAL)) {
+    bool real_mode = (type == ACCESS_CODE) ? !FIELD_EX64(env->msr, MSR, IR)
+                                           : !FIELD_EX64(env->msr, MSR, DR);
+    if (real_mode) {
         memset(ctx, 0, sizeof(*ctx));
         ctx->raddr = eaddr;
         ctx->prot = PAGE_READ | PAGE_WRITE | PAGE_EXEC;

This still changes beahviour of MPC8xx MMU doesn't it? It's supposed
to abort always.

I don't think it can get here because there's still an abort case in 
ppc_tlb_invalidate_all() which is called from ppc_cpu_reset_hold() so it 
will likely crash before it could call anything here. But if you think 
it's necessary I could add a case for it in ppc_xlate() maybe.

Regards,
BALATON Zoltan