From 1de29aef17a7d70dbc04a7fe51e18942e3ebe313 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Tue, 5 May 2015 09:18:23 +0200 Subject: [PATCH] softmmu: support up to 12 MMU modes At 8k per TLB (for 64-bit host or target), 8 or more modes make the TLBs bigger than 64k, and some RISC TCG backends do not like that. On the affected hosts, cut the TLB size in half---there is still a measurable speedup on PPC with the next patch. Signed-off-by: Paolo Bonzini Message-Id: <1424436345-37924-3-git-send-email-pbonzini@redhat.com> Reviewed-by: Richard Henderson Signed-off-by: Alexander Graf --- include/exec/cpu-defs.h | 35 +++++++++++++- include/exec/cpu_ldst.h | 104 +++++++++++++++++++++++++++++++++++++--- 2 files changed, 131 insertions(+), 8 deletions(-) diff --git a/include/exec/cpu-defs.h b/include/exec/cpu-defs.h index 3f56546066..d5aecaf49e 100644 --- a/include/exec/cpu-defs.h +++ b/include/exec/cpu-defs.h @@ -27,6 +27,7 @@ #include #include "qemu/osdep.h" #include "qemu/queue.h" +#include "tcg-target.h" #ifndef CONFIG_USER_ONLY #include "exec/hwaddr.h" #endif @@ -70,8 +71,6 @@ typedef uint64_t target_ulong; #define TB_JMP_PAGE_MASK (TB_JMP_CACHE_SIZE - TB_JMP_PAGE_SIZE) #if !defined(CONFIG_USER_ONLY) -#define CPU_TLB_BITS 8 -#define CPU_TLB_SIZE (1 << CPU_TLB_BITS) /* use a fully associative victim tlb of 8 entries */ #define CPU_VTLB_SIZE 8 @@ -81,6 +80,38 @@ typedef uint64_t target_ulong; #define CPU_TLB_ENTRY_BITS 5 #endif +/* TCG_TARGET_TLB_DISPLACEMENT_BITS is used in CPU_TLB_BITS to ensure that + * the TLB is not unnecessarily small, but still small enough for the + * TLB lookup instruction sequence used by the TCG target. + * + * TCG will have to generate an operand as large as the distance between + * env and the tlb_table[NB_MMU_MODES - 1][0].addend. For simplicity, + * the TCG targets just round everything up to the next power of two, and + * count bits. This works because: 1) the size of each TLB is a largish + * power of two, 2) and because the limit of the displacement is really close + * to a power of two, 3) the offset of tlb_table[0][0] inside env is smaller + * than the size of a TLB. + * + * For example, the maximum displacement 0xFFF0 on PPC and MIPS, but TCG + * just says "the displacement is 16 bits". TCG_TARGET_TLB_DISPLACEMENT_BITS + * then ensures that tlb_table at least 0x8000 bytes large ("not unnecessarily + * small": 2^15). The operand then will come up smaller than 0xFFF0 without + * any particular care, because the TLB for a single MMU mode is larger than + * 0x10000-0xFFF0=16 bytes. In the end, the maximum value of the operand + * could be something like 0xC000 (the offset of the last TLB table) plus + * 0x18 (the offset of the addend field in each TLB entry) plus the offset + * of tlb_table inside env (which is non-trivial but not huge). + */ +#define CPU_TLB_BITS \ + MIN(8, \ + TCG_TARGET_TLB_DISPLACEMENT_BITS - CPU_TLB_ENTRY_BITS - \ + (NB_MMU_MODES <= 1 ? 0 : \ + NB_MMU_MODES <= 2 ? 1 : \ + NB_MMU_MODES <= 4 ? 2 : \ + NB_MMU_MODES <= 8 ? 3 : 4)) + +#define CPU_TLB_SIZE (1 << CPU_TLB_BITS) + typedef struct CPUTLBEntry { /* bit TARGET_LONG_BITS to TARGET_PAGE_BITS : virtual address bit TARGET_PAGE_BITS-1..4 : Nonzero for accesses that should not diff --git a/include/exec/cpu_ldst.h b/include/exec/cpu_ldst.h index 1673287189..0ec398c0f8 100644 --- a/include/exec/cpu_ldst.h +++ b/include/exec/cpu_ldst.h @@ -263,12 +263,104 @@ uint64_t helper_ldq_cmmu(CPUArchState *env, target_ulong addr, int mmu_idx); #undef MEMSUFFIX #endif /* (NB_MMU_MODES >= 7) */ -#if (NB_MMU_MODES > 7) -/* Note that supporting NB_MMU_MODES == 9 would require - * changes to at least the ARM TCG backend. - */ -#error "NB_MMU_MODES > 7 is not supported for now" -#endif /* (NB_MMU_MODES > 7) */ +#if (NB_MMU_MODES >= 8) && defined(MMU_MODE7_SUFFIX) + +#define CPU_MMU_INDEX 7 +#define MEMSUFFIX MMU_MODE7_SUFFIX +#define DATA_SIZE 1 +#include "exec/cpu_ldst_template.h" + +#define DATA_SIZE 2 +#include "exec/cpu_ldst_template.h" + +#define DATA_SIZE 4 +#include "exec/cpu_ldst_template.h" + +#define DATA_SIZE 8 +#include "exec/cpu_ldst_template.h" +#undef CPU_MMU_INDEX +#undef MEMSUFFIX +#endif /* (NB_MMU_MODES >= 8) */ + +#if (NB_MMU_MODES >= 9) && defined(MMU_MODE8_SUFFIX) + +#define CPU_MMU_INDEX 8 +#define MEMSUFFIX MMU_MODE8_SUFFIX +#define DATA_SIZE 1 +#include "exec/cpu_ldst_template.h" + +#define DATA_SIZE 2 +#include "exec/cpu_ldst_template.h" + +#define DATA_SIZE 4 +#include "exec/cpu_ldst_template.h" + +#define DATA_SIZE 8 +#include "exec/cpu_ldst_template.h" +#undef CPU_MMU_INDEX +#undef MEMSUFFIX +#endif /* (NB_MMU_MODES >= 9) */ + +#if (NB_MMU_MODES >= 10) && defined(MMU_MODE9_SUFFIX) + +#define CPU_MMU_INDEX 9 +#define MEMSUFFIX MMU_MODE9_SUFFIX +#define DATA_SIZE 1 +#include "exec/cpu_ldst_template.h" + +#define DATA_SIZE 2 +#include "exec/cpu_ldst_template.h" + +#define DATA_SIZE 4 +#include "exec/cpu_ldst_template.h" + +#define DATA_SIZE 8 +#include "exec/cpu_ldst_template.h" +#undef CPU_MMU_INDEX +#undef MEMSUFFIX +#endif /* (NB_MMU_MODES >= 10) */ + +#if (NB_MMU_MODES >= 11) && defined(MMU_MODE10_SUFFIX) + +#define CPU_MMU_INDEX 10 +#define MEMSUFFIX MMU_MODE10_SUFFIX +#define DATA_SIZE 1 +#include "exec/cpu_ldst_template.h" + +#define DATA_SIZE 2 +#include "exec/cpu_ldst_template.h" + +#define DATA_SIZE 4 +#include "exec/cpu_ldst_template.h" + +#define DATA_SIZE 8 +#include "exec/cpu_ldst_template.h" +#undef CPU_MMU_INDEX +#undef MEMSUFFIX +#endif /* (NB_MMU_MODES >= 11) */ + +#if (NB_MMU_MODES >= 12) && defined(MMU_MODE11_SUFFIX) + +#define CPU_MMU_INDEX 11 +#define MEMSUFFIX MMU_MODE11_SUFFIX +#define DATA_SIZE 1 +#include "exec/cpu_ldst_template.h" + +#define DATA_SIZE 2 +#include "exec/cpu_ldst_template.h" + +#define DATA_SIZE 4 +#include "exec/cpu_ldst_template.h" + +#define DATA_SIZE 8 +#include "exec/cpu_ldst_template.h" +#undef CPU_MMU_INDEX +#undef MEMSUFFIX +#endif /* (NB_MMU_MODES >= 12) */ + +#if (NB_MMU_MODES > 12) +#error "NB_MMU_MODES > 12 is not supported for now" +#endif /* (NB_MMU_MODES > 12) */ /* these access are slower, they must be as rare as possible */ #define CPU_MMU_INDEX (cpu_mmu_index(env)) -- GitLab