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target-arm: Prepare translation for AArch64 code
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This patch adds all the prerequisites for AArch64 support that didn't
fit into split up patches. It extends important bits in the core cpu
headers to also take AArch64 mode into account.

Add new ARM_TBFLAG_AARCH64_STATE translation buffer flag
indicate an ARMv8 cpu running in aarch64 mode vs aarch32 mode.

Signed-off-by: Alexander Graf <[email protected]>
Signed-off-by: John Rigby <[email protected]>
Signed-off-by: Peter Maydell <[email protected]>
Message-id: [email protected]
Message-id: [email protected]
[PMM:
 * rearranged tbflags so AArch64? is bit 31 and if it is set then
  30..0 are freely available for whatever makes most sense for that mode
 * added version bump since we change VFP migration state
 * added a comment about how VFP/Neon register state works
 * physical address space is 48 bits, not 64
 * added ARM_FEATURE_AARCH64 flag to identify 64-bit capable CPUs
]
Signed-off-by: Peter Maydell <[email protected]>
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@agraf @pm215
agraf authored and pm215 committed Sep 10, 2013
1 parent 15ee776 commit 3926cc8
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Showing 5 changed files with 151 additions and 38 deletions.
8 changes: 8 additions & 0 deletions target-arm/cpu.c
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Original file line number Diff line number Diff line change
Expand Up @@ -84,6 +84,11 @@ static void arm_cpu_reset(CPUState *s)
env->iwmmxt.cregs[ARM_IWMMXT_wCID] = 0x69051000 | 'Q';
}

if (arm_feature(env, ARM_FEATURE_AARCH64)) {
/* 64 bit CPUs always start in 64 bit mode */
env->aarch64 = 1;
}

#if defined(CONFIG_USER_ONLY)
env->uncached_cpsr = ARM_CPU_MODE_USR;
/* For user mode we must enable access to coprocessors */
Expand Down Expand Up @@ -834,6 +839,9 @@ static void arm_any_initfn(Object *obj)
set_feature(&cpu->env, ARM_FEATURE_THUMB2EE);
set_feature(&cpu->env, ARM_FEATURE_ARM_DIV);
set_feature(&cpu->env, ARM_FEATURE_V7MP);
#ifdef TARGET_AARCH64
set_feature(&cpu->env, ARM_FEATURE_AARCH64);
#endif
cpu->midr = 0xffffffff;
}
#endif
Expand Down
134 changes: 109 additions & 25 deletions target-arm/cpu.h
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Original file line number Diff line number Diff line change
Expand Up @@ -19,13 +19,19 @@
#ifndef CPU_ARM_H
#define CPU_ARM_H

#define TARGET_LONG_BITS 32
#include "config.h"

#define ELF_MACHINE EM_ARM
#if defined(TARGET_AARCH64)
/* AArch64 definitions */
# define TARGET_LONG_BITS 64
# define ELF_MACHINE EM_AARCH64
#else
# define TARGET_LONG_BITS 32
# define ELF_MACHINE EM_ARM
#endif

#define CPUArchState struct CPUARMState

#include "config.h"
#include "qemu-common.h"
#include "exec/cpu-defs.h"

Expand Down Expand Up @@ -97,6 +103,20 @@ typedef struct ARMGenericTimer {
typedef struct CPUARMState {
/* Regs for current mode. */
uint32_t regs[16];

/* 32/64 switch only happens when taking and returning from
* exceptions so the overlap semantics are taken care of then
* instead of having a complicated union.
*/
/* Regs for A64 mode. */
uint64_t xregs[32];
uint64_t pc;
/* TODO: pstate doesn't correspond to an architectural register;
* it would be better modelled as the underlying fields.
*/
uint32_t pstate;
uint32_t aarch64; /* 1 if CPU is in aarch64 state; inverse of PSTATE.nRW */

/* Frequently accessed CPSR bits are stored separately for efficiency.
This contains all the other bits. Use cpsr_{read,write} to access
the whole CPSR. */
Expand Down Expand Up @@ -175,6 +195,11 @@ typedef struct CPUARMState {
uint32_t c15_power_control; /* power control */
} cp15;

/* System registers (AArch64) */
struct {
uint64_t tpidr_el0;
} sr;

struct {
uint32_t other_sp;
uint32_t vecbase;
Expand All @@ -191,7 +216,22 @@ typedef struct CPUARMState {

/* VFP coprocessor state. */
struct {
float64 regs[32];
/* VFP/Neon register state. Note that the mapping between S, D and Q
* views of the register bank differs between AArch64 and AArch32:
* In AArch32:
* Qn = regs[2n+1]:regs[2n]
* Dn = regs[n]
* Sn = regs[n/2] bits 31..0 for even n, and bits 63..32 for odd n
* (and regs[32] to regs[63] are inaccessible)
* In AArch64:
* Qn = regs[2n+1]:regs[2n]
* Dn = regs[2n]
* Sn = regs[2n] bits 31..0
* This corresponds to the architecturally defined mapping between
* the two execution states, and means we do not need to explicitly
* map these registers when changing states.
*/
float64 regs[64];

uint32_t xregs[16];
/* We store these fpcsr fields separately for convenience. */
Expand Down Expand Up @@ -261,6 +301,20 @@ int bank_number(int mode);
void switch_mode(CPUARMState *, int);
uint32_t do_arm_semihosting(CPUARMState *env);

static inline bool is_a64(CPUARMState *env)
{
return env->aarch64;
}

#define PSTATE_N_SHIFT 3
#define PSTATE_N (1 << PSTATE_N_SHIFT)
#define PSTATE_Z_SHIFT 2
#define PSTATE_Z (1 << PSTATE_Z_SHIFT)
#define PSTATE_C_SHIFT 1
#define PSTATE_C (1 << PSTATE_C_SHIFT)
#define PSTATE_V_SHIFT 0
#define PSTATE_V (1 << PSTATE_V_SHIFT)

/* you can call this signal handler from your SIGBUS and SIGSEGV
signal handlers to inform the virtual CPU of exceptions. non zero
is returned if the signal was handled by the virtual CPU. */
Expand Down Expand Up @@ -409,6 +463,7 @@ enum arm_features {
ARM_FEATURE_PXN, /* has Privileged Execute Never bit */
ARM_FEATURE_LPAE, /* has Large Physical Address Extension */
ARM_FEATURE_V8,
ARM_FEATURE_AARCH64, /* supports 64 bit mode */
};

static inline int arm_feature(CPUARMState *env, int feature)
Expand Down Expand Up @@ -729,8 +784,13 @@ bool write_cpustate_to_list(ARMCPU *cpu);
#define TARGET_PAGE_BITS 10
#endif

#define TARGET_PHYS_ADDR_SPACE_BITS 40
#define TARGET_VIRT_ADDR_SPACE_BITS 32
#if defined(TARGET_AARCH64)
# define TARGET_PHYS_ADDR_SPACE_BITS 48
# define TARGET_VIRT_ADDR_SPACE_BITS 64
#else
# define TARGET_PHYS_ADDR_SPACE_BITS 40
# define TARGET_VIRT_ADDR_SPACE_BITS 32
#endif

static inline CPUARMState *cpu_init(const char *cpu_model)
{
Expand All @@ -757,7 +817,13 @@ static inline int cpu_mmu_index (CPUARMState *env)

#include "exec/cpu-all.h"

/* Bit usage in the TB flags field: */
/* Bit usage in the TB flags field: bit 31 indicates whether we are
* in 32 or 64 bit mode. The meaning of the other bits depends on that.
*/
#define ARM_TBFLAG_AARCH64_STATE_SHIFT 31
#define ARM_TBFLAG_AARCH64_STATE_MASK (1U << ARM_TBFLAG_AARCH64_STATE_SHIFT)

/* Bit usage when in AArch32 state: */
#define ARM_TBFLAG_THUMB_SHIFT 0
#define ARM_TBFLAG_THUMB_MASK (1 << ARM_TBFLAG_THUMB_SHIFT)
#define ARM_TBFLAG_VECLEN_SHIFT 1
Expand All @@ -772,9 +838,12 @@ static inline int cpu_mmu_index (CPUARMState *env)
#define ARM_TBFLAG_CONDEXEC_MASK (0xff << ARM_TBFLAG_CONDEXEC_SHIFT)
#define ARM_TBFLAG_BSWAP_CODE_SHIFT 16
#define ARM_TBFLAG_BSWAP_CODE_MASK (1 << ARM_TBFLAG_BSWAP_CODE_SHIFT)
/* Bits 31..17 are currently unused. */

/* Bit usage when in AArch64 state: currently no bits defined */

/* some convenience accessor macros */
#define ARM_TBFLAG_AARCH64_STATE(F) \
(((F) & ARM_TBFLAG_AARCH64_STATE_MASK) >> ARM_TBFLAG_AARCH64_STATE_SHIFT)
#define ARM_TBFLAG_THUMB(F) \
(((F) & ARM_TBFLAG_THUMB_MASK) >> ARM_TBFLAG_THUMB_SHIFT)
#define ARM_TBFLAG_VECLEN(F) \
Expand All @@ -793,25 +862,31 @@ static inline int cpu_mmu_index (CPUARMState *env)
static inline void cpu_get_tb_cpu_state(CPUARMState *env, target_ulong *pc,
target_ulong *cs_base, int *flags)
{
int privmode;
*pc = env->regs[15];
*cs_base = 0;
*flags = (env->thumb << ARM_TBFLAG_THUMB_SHIFT)
| (env->vfp.vec_len << ARM_TBFLAG_VECLEN_SHIFT)
| (env->vfp.vec_stride << ARM_TBFLAG_VECSTRIDE_SHIFT)
| (env->condexec_bits << ARM_TBFLAG_CONDEXEC_SHIFT)
| (env->bswap_code << ARM_TBFLAG_BSWAP_CODE_SHIFT);
if (arm_feature(env, ARM_FEATURE_M)) {
privmode = !((env->v7m.exception == 0) && (env->v7m.control & 1));
if (is_a64(env)) {
*pc = env->pc;
*flags = ARM_TBFLAG_AARCH64_STATE_MASK;
} else {
privmode = (env->uncached_cpsr & CPSR_M) != ARM_CPU_MODE_USR;
}
if (privmode) {
*flags |= ARM_TBFLAG_PRIV_MASK;
}
if (env->vfp.xregs[ARM_VFP_FPEXC] & (1 << 30)) {
*flags |= ARM_TBFLAG_VFPEN_MASK;
int privmode;
*pc = env->regs[15];
*flags = (env->thumb << ARM_TBFLAG_THUMB_SHIFT)
| (env->vfp.vec_len << ARM_TBFLAG_VECLEN_SHIFT)
| (env->vfp.vec_stride << ARM_TBFLAG_VECSTRIDE_SHIFT)
| (env->condexec_bits << ARM_TBFLAG_CONDEXEC_SHIFT)
| (env->bswap_code << ARM_TBFLAG_BSWAP_CODE_SHIFT);
if (arm_feature(env, ARM_FEATURE_M)) {
privmode = !((env->v7m.exception == 0) && (env->v7m.control & 1));
} else {
privmode = (env->uncached_cpsr & CPSR_M) != ARM_CPU_MODE_USR;
}
if (privmode) {
*flags |= ARM_TBFLAG_PRIV_MASK;
}
if (env->vfp.xregs[ARM_VFP_FPEXC] & (1 << 30)) {
*flags |= ARM_TBFLAG_VFPEN_MASK;
}
}

*cs_base = 0;
}

static inline bool cpu_has_work(CPUState *cpu)
Expand All @@ -822,6 +897,15 @@ static inline bool cpu_has_work(CPUState *cpu)

#include "exec/exec-all.h"

static inline void cpu_pc_from_tb(CPUARMState *env, TranslationBlock *tb)
{
if (ARM_TBFLAG_AARCH64_STATE(tb->flags)) {
env->pc = tb->pc;
} else {
env->regs[15] = tb->pc;
}
}

/* Load an instruction and return it in the standard little-endian order */
static inline uint32_t arm_ldl_code(CPUARMState *env, target_ulong addr,
bool do_swap)
Expand Down
8 changes: 4 additions & 4 deletions target-arm/machine.c
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Original file line number Diff line number Diff line change
Expand Up @@ -37,11 +37,11 @@ static const VMStateInfo vmstate_fpscr = {

static const VMStateDescription vmstate_vfp = {
.name = "cpu/vfp",
.version_id = 2,
.minimum_version_id = 2,
.minimum_version_id_old = 2,
.version_id = 3,
.minimum_version_id = 3,
.minimum_version_id_old = 3,
.fields = (VMStateField[]) {
VMSTATE_FLOAT64_ARRAY(env.vfp.regs, ARMCPU, 32),
VMSTATE_FLOAT64_ARRAY(env.vfp.regs, ARMCPU, 64),
/* The xregs array is a little awkward because element 1 (FPSCR)
* requires a specific accessor, so we have to split it up in
* the vmstate:
Expand Down
38 changes: 29 additions & 9 deletions target-arm/translate.c
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Original file line number Diff line number Diff line change
Expand Up @@ -10012,16 +10012,32 @@ static inline void gen_intermediate_code_internal(ARMCPU *cpu,
dc->pc = pc_start;
dc->singlestep_enabled = cs->singlestep_enabled;
dc->condjmp = 0;
dc->thumb = ARM_TBFLAG_THUMB(tb->flags);
dc->bswap_code = ARM_TBFLAG_BSWAP_CODE(tb->flags);
dc->condexec_mask = (ARM_TBFLAG_CONDEXEC(tb->flags) & 0xf) << 1;
dc->condexec_cond = ARM_TBFLAG_CONDEXEC(tb->flags) >> 4;

if (ARM_TBFLAG_AARCH64_STATE(tb->flags)) {
dc->aarch64 = 1;
dc->thumb = 0;
dc->bswap_code = 0;
dc->condexec_mask = 0;
dc->condexec_cond = 0;
#if !defined(CONFIG_USER_ONLY)
dc->user = 0;
#endif
dc->vfp_enabled = 0;
dc->vec_len = 0;
dc->vec_stride = 0;
} else {
dc->aarch64 = 0;
dc->thumb = ARM_TBFLAG_THUMB(tb->flags);
dc->bswap_code = ARM_TBFLAG_BSWAP_CODE(tb->flags);
dc->condexec_mask = (ARM_TBFLAG_CONDEXEC(tb->flags) & 0xf) << 1;
dc->condexec_cond = ARM_TBFLAG_CONDEXEC(tb->flags) >> 4;
#if !defined(CONFIG_USER_ONLY)
dc->user = (ARM_TBFLAG_PRIV(tb->flags) == 0);
dc->user = (ARM_TBFLAG_PRIV(tb->flags) == 0);
#endif
dc->vfp_enabled = ARM_TBFLAG_VFPEN(tb->flags);
dc->vec_len = ARM_TBFLAG_VECLEN(tb->flags);
dc->vec_stride = ARM_TBFLAG_VECSTRIDE(tb->flags);
dc->vfp_enabled = ARM_TBFLAG_VFPEN(tb->flags);
dc->vec_len = ARM_TBFLAG_VECLEN(tb->flags);
dc->vec_stride = ARM_TBFLAG_VECSTRIDE(tb->flags);
}
cpu_F0s = tcg_temp_new_i32();
cpu_F1s = tcg_temp_new_i32();
cpu_F0d = tcg_temp_new_i64();
Expand Down Expand Up @@ -10324,6 +10340,10 @@ void arm_cpu_dump_state(CPUState *cs, FILE *f, fprintf_function cpu_fprintf,

void restore_state_to_opc(CPUARMState *env, TranslationBlock *tb, int pc_pos)
{
env->regs[15] = tcg_ctx.gen_opc_pc[pc_pos];
if (is_a64(env)) {
env->pc = tcg_ctx.gen_opc_pc[pc_pos];
} else {
env->regs[15] = tcg_ctx.gen_opc_pc[pc_pos];
}
env->condexec_bits = gen_opc_condexec_bits[pc_pos];
}
1 change: 1 addition & 0 deletions target-arm/translate.h
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Original file line number Diff line number Diff line change
Expand Up @@ -22,6 +22,7 @@ typedef struct DisasContext {
int vfp_enabled;
int vec_len;
int vec_stride;
int aarch64;
} DisasContext;

extern TCGv_ptr cpu_env;
Expand Down

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