MIPS: tlbex: Remove cpu_has_local_ebase
authorPaul Burton <paul.burton@mips.com>
Sat, 31 Aug 2019 15:40:46 +0000 (15:40 +0000)
committerPaul Burton <paul.burton@mips.com>
Tue, 3 Sep 2019 13:20:54 +0000 (14:20 +0100)
The cpu_has_local_ebase macro is, confusingly, not used to indicate
whether the EBase register is local to a CPU or not. Instead it
indicates whether we want to generate the TLB refill exception vector
each time a CPU is brought online. Doing this makes little sense on any
system, since we always use the same value for EBase & thus we cannot
have different TLB refill exception handlers per CPU.

Regenerating the code is not only pointless but also can be actively
harmful, as commit 8759934e2b6b ("MIPS: Build uasm-generated code only
once to avoid CPU Hotplug problem") described. That commit introduced
cpu_has_local_ebase to disable the handler regeneration for Loongson
machines, but this is by no means a Loongson-specific problem.

Remove cpu_has_local_ebase & simply generate the TLB refill handler once
during boot, just like the rest of the TLB exception handlers.

Signed-off-by: Paul Burton <paul.burton@mips.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Cc: linux-mips@vger.kernel.org
arch/mips/include/asm/cpu-features.h
arch/mips/include/asm/mach-dec/cpu-feature-overrides.h
arch/mips/include/asm/mach-loongson64/cpu-feature-overrides.h
arch/mips/mm/tlbex.c

index 4e2bea8875f5f4acc427f5df307e9dd86edd5bb6..983a6a7f43a111a3d2de88a36e6747301f23b8c2 100644 (file)
 #ifndef cpu_has_pindexed_dcache
 #define cpu_has_pindexed_dcache        (cpu_data[0].dcache.flags & MIPS_CACHE_PINDEX)
 #endif
-#ifndef cpu_has_local_ebase
-#define cpu_has_local_ebase    1
-#endif
 
 /*
  * I-Cache snoops remote store.         This only matters on SMP.  Some multiprocessors
index 1c11310bc8ad0878cf5343a7d641fff8c57e803a..00beb69bfab9829e6f4b68ed93797e48eb4c0160 100644 (file)
@@ -32,7 +32,6 @@
 #define cpu_has_vtag_icache            0
 #define cpu_has_ic_fills_f_dc          0
 #define cpu_has_pindexed_dcache                0
-#define cpu_has_local_ebase            0
 #define cpu_icache_snoops_remote_store 1
 #define cpu_has_mips_4                 0
 #define cpu_has_mips_5                 0
index 581915ce231c7c522d7080d2c3afcb86c1c67b73..4aca25f2ff06c4aeb0d7f78ecdca3c864b0a88d3 100644 (file)
@@ -43,7 +43,6 @@
 #define cpu_has_vint           0
 #define cpu_has_vtag_icache    0
 #define cpu_has_watch          1
-#define cpu_has_local_ebase    0
 
 #ifdef CONFIG_CPU_LOONGSON3
 #define cpu_has_wsbh           1
index 6e3ca9cc52493d250b721a3a53bcd4f24dbeed3b..e01cb33bfa1a78a67638d5b27fb8fc7e43df3e09 100644 (file)
@@ -2609,12 +2609,9 @@ void build_tlb_refill_handler(void)
 
        if (cpu_has_3kex) {
 #ifndef CONFIG_MIPS_PGD_C0_CONTEXT
-               if (cpu_has_local_ebase)
-                       build_r3000_tlb_refill_handler();
                if (!run_once) {
-                       if (!cpu_has_local_ebase)
-                               build_r3000_tlb_refill_handler();
                        build_setup_pgd();
+                       build_r3000_tlb_refill_handler();
                        build_r3000_tlb_load_handler();
                        build_r3000_tlb_store_handler();
                        build_r3000_tlb_modify_handler();
@@ -2638,13 +2635,11 @@ void build_tlb_refill_handler(void)
                build_r4000_tlb_modify_handler();
                if (cpu_has_ldpte)
                        build_loongson3_tlb_refill_handler();
-               else if (!cpu_has_local_ebase)
+               else
                        build_r4000_tlb_refill_handler();
                flush_tlb_handlers();
                run_once++;
        }
-       if (cpu_has_local_ebase)
-               build_r4000_tlb_refill_handler();
        if (cpu_has_xpa)
                config_xpa_params();
        if (cpu_has_htw)