From: Thomas Huth Date: Fri, 24 Oct 2025 06:57:25 +0000 (+0200) Subject: target/ppc/cpu_init: Simplify the setup of the TLBxCFG SPR registers X-Git-Tag: v10.2.0-rc1~31^2~7 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=14e4390a3210d13cfc340dc3289350bac59ea2e9;p=thirdparty%2Fqemu.git target/ppc/cpu_init: Simplify the setup of the TLBxCFG SPR registers The next commit is going to remove init_proc_e200(), which is one of the two calling sites of register_BookE206_sprs(). This causes recent versions of GCC to inline the register_BookE206_sprs() function into the other only remaining calling site, init_proc_e500(), which in turn causes some false-positives compiler warnings: In file included from ../../devel/qemu/target/ppc/cpu_init.c:46: In function ‘register_BookE206_sprs’, inlined from ‘init_proc_e500’ at ../../devel/qemu/target/ppc/cpu_init.c:2910:5: ../../devel/qemu/target/ppc/cpu_init.c:897:29: error: array subscript 3 is outside array bounds of ‘uint32_t[2]’ {aka ‘unsigned int[2]’} [-Werror=array-bounds=] 897 | tlbncfg[3]); | ~~~~~~~^~~ ../../devel/qemu/target/ppc/spr_common.h:61:39: note: in definition of macro ‘spr_register_kvm_hv’ 61 | KVM_ARG(one_reg_id) initial_value) | ^~~~~~~~~~~~~ ../../devel/qemu/target/ppc/spr_common.h:77:5: note: in expansion of macro ‘spr_register_kvm’ 77 | spr_register_kvm(env, num, name, uea_read, uea_write, \ | ^~~~~~~~~~~~~~~~ ../../devel/qemu/target/ppc/cpu_init.c:894:9: note: in expansion of macro ‘spr_register’ 894 | spr_register(env, SPR_BOOKE_TLB3CFG, "TLB3CFG", | ^~~~~~~~~~~~ ../../devel/qemu/target/ppc/cpu_init.c: In function ‘init_proc_e500’: ../../devel/qemu/target/ppc/cpu_init.c:2809:14: note: at offset 12 into object ‘tlbncfg’ of size 8 2809 | uint32_t tlbncfg[2]; | ^~~~~~~ cc1: all warnings being treated as errors init_proc_e500() only defines "uint32_t tlbncfg[2];", but it is OK since it also sets "env->nb_ways = 2", so the code that GCC warns about in register_BookE206_sprs() is never reached. Unfortunately, GCC is not smart enough to see this, so it emits these warnings. To fix it, let's simplify the code in register_BookE206_sprs() a little bit to set up the SPRs in a loop, so we don't reference the tlbncfg[3] entry directly anymore. Signed-off-by: Thomas Huth Reviewed-by: Chinmay Rath Signed-off-by: Harsh Prateek Bora Link: https://lore.kernel.org/r/20251024065726.738005-2-thuth@redhat.com Message-ID: <20251024065726.738005-2-thuth@redhat.com> --- diff --git a/target/ppc/cpu_init.c b/target/ppc/cpu_init.c index 3aa3aefc13..12c645699e 100644 --- a/target/ppc/cpu_init.c +++ b/target/ppc/cpu_init.c @@ -850,6 +850,13 @@ static void register_BookE206_sprs(CPUPPCState *env, uint32_t mas_mask, SPR_BOOKE_MAS0, SPR_BOOKE_MAS1, SPR_BOOKE_MAS2, SPR_BOOKE_MAS3, SPR_BOOKE_MAS4, SPR_BOOKE_MAS5, SPR_BOOKE_MAS6, SPR_BOOKE_MAS7, }; + const char *tlbcfg_names[4] = { + "TLB0CFG", "TLB1CFG", "TLB2CFG", "TLB3CFG", + }; + const int tlbcfg_sprn[4] = { + SPR_BOOKE_TLB0CFG, SPR_BOOKE_TLB1CFG, + SPR_BOOKE_TLB2CFG, SPR_BOOKE_TLB3CFG, + }; int i; /* TLB assist registers */ @@ -889,34 +896,13 @@ static void register_BookE206_sprs(CPUPPCState *env, uint32_t mas_mask, SPR_NOACCESS, SPR_NOACCESS, &spr_read_generic, SPR_NOACCESS, mmucfg); - switch (env->nb_ways) { - case 4: - spr_register(env, SPR_BOOKE_TLB3CFG, "TLB3CFG", - SPR_NOACCESS, SPR_NOACCESS, - &spr_read_generic, SPR_NOACCESS, - tlbncfg[3]); - /* Fallthru */ - case 3: - spr_register(env, SPR_BOOKE_TLB2CFG, "TLB2CFG", - SPR_NOACCESS, SPR_NOACCESS, - &spr_read_generic, SPR_NOACCESS, - tlbncfg[2]); - /* Fallthru */ - case 2: - spr_register(env, SPR_BOOKE_TLB1CFG, "TLB1CFG", - SPR_NOACCESS, SPR_NOACCESS, - &spr_read_generic, SPR_NOACCESS, - tlbncfg[1]); - /* Fallthru */ - case 1: - spr_register(env, SPR_BOOKE_TLB0CFG, "TLB0CFG", + + assert(env->nb_ways <= ARRAY_SIZE(tlbcfg_names)); + for (i = 0; i < env->nb_ways; i++) { + spr_register(env, tlbcfg_sprn[i], tlbcfg_names[i], SPR_NOACCESS, SPR_NOACCESS, &spr_read_generic, SPR_NOACCESS, - tlbncfg[0]); - /* Fallthru */ - case 0: - default: - break; + tlbncfg[i]); } #endif }