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target/arm: Reorg ARMCPRegInfo type field bits

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Instead of defining ARM_CP_FLAG_MASK to remove flags,
define ARM_CP_SPECIAL_MASK to isolate special cases.
Sort the specials to the low bits. Use an enum.

Split the large comment block so as to document each
value separately.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 20220501055028.646596-6-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This commit is contained in:
Richard Henderson 2022-04-30 22:49:47 -07:00 committed by Peter Maydell
parent 10b0220e45
commit 87c3f0f2f7
5 changed files with 92 additions and 58 deletions
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130
target/arm/cpregs.h
View File

@ -22,57 +22,87 @@
#define TARGET_ARM_CPREGS_H
/*
* ARMCPRegInfo type field bits. If the SPECIAL bit is set this is a
* special-behaviour cp reg and bits [11..8] indicate what behaviour
* it has. Otherwise it is a simple cp reg, where CONST indicates that
* TCG can assume the value to be constant (ie load at translate time)
* and 64BIT indicates a 64 bit wide coprocessor register. SUPPRESS_TB_END
* indicates that the TB should not be ended after a write to this register
* (the default is that the TB ends after cp writes). OVERRIDE permits
* a register definition to override a previous definition for the
* same (cp, is64, crn, crm, opc1, opc2) tuple: either the new or the
* old must have the OVERRIDE bit set.
* ALIAS indicates that this register is an alias view of some underlying
* state which is also visible via another register, and that the other
* register is handling migration and reset; registers marked ALIAS will not be
* migrated but may have their state set by syncing of register state from KVM.
* NO_RAW indicates that this register has no underlying state and does not
* support raw access for state saving/loading; it will not be used for either
* migration or KVM state synchronization. (Typically this is for "registers"
* which are actually used as instructions for cache maintenance and so on.)
* IO indicates that this register does I/O and therefore its accesses
* need to be marked with gen_io_start() and also end the TB. In particular,
* registers which implement clocks or timers require this.
* RAISES_EXC is for when the read or write hook might raise an exception;
* the generated code will synchronize the CPU state before calling the hook
* so that it is safe for the hook to call raise_exception().
* NEWEL is for writes to registers that might change the exception
* level - typically on older ARM chips. For those cases we need to
* re-read the new el when recomputing the translation flags.
* ARMCPRegInfo type field bits:
*/
#define ARM_CP_SPECIAL 0x0001
#define ARM_CP_CONST 0x0002
#define ARM_CP_64BIT 0x0004
#define ARM_CP_SUPPRESS_TB_END 0x0008
#define ARM_CP_OVERRIDE 0x0010
#define ARM_CP_ALIAS 0x0020
#define ARM_CP_IO 0x0040
#define ARM_CP_NO_RAW 0x0080
#define ARM_CP_NOP (ARM_CP_SPECIAL | 0x0100)
#define ARM_CP_WFI (ARM_CP_SPECIAL | 0x0200)
#define ARM_CP_NZCV (ARM_CP_SPECIAL | 0x0300)
#define ARM_CP_CURRENTEL (ARM_CP_SPECIAL | 0x0400)
#define ARM_CP_DC_ZVA (ARM_CP_SPECIAL | 0x0500)
#define ARM_CP_DC_GVA (ARM_CP_SPECIAL | 0x0600)
#define ARM_CP_DC_GZVA (ARM_CP_SPECIAL | 0x0700)
#define ARM_LAST_SPECIAL ARM_CP_DC_GZVA
#define ARM_CP_FPU 0x1000
#define ARM_CP_SVE 0x2000
#define ARM_CP_NO_GDB 0x4000
#define ARM_CP_RAISES_EXC 0x8000
#define ARM_CP_NEWEL 0x10000
/* Mask of only the flag bits in a type field */
#define ARM_CP_FLAG_MASK 0x1f0ff
enum {
/*
* Register must be handled specially during translation.
* The method is one of the values below:
*/
ARM_CP_SPECIAL_MASK = 0x000f,
/* Special: no change to PE state: writes ignored, reads ignored. */
ARM_CP_NOP = 0x0001,
/* Special: sysreg is WFI, for v5 and v6. */
ARM_CP_WFI = 0x0002,
/* Special: sysreg is NZCV. */
ARM_CP_NZCV = 0x0003,
/* Special: sysreg is CURRENTEL. */
ARM_CP_CURRENTEL = 0x0004,
/* Special: sysreg is DC ZVA or similar. */
ARM_CP_DC_ZVA = 0x0005,
ARM_CP_DC_GVA = 0x0006,
ARM_CP_DC_GZVA = 0x0007,
/* Flag: reads produce resetvalue; writes ignored. */
ARM_CP_CONST = 1 << 4,
/* Flag: For ARM_CP_STATE_AA32, sysreg is 64-bit. */
ARM_CP_64BIT = 1 << 5,
/*
* Flag: TB should not be ended after a write to this register
* (the default is that the TB ends after cp writes).
*/
ARM_CP_SUPPRESS_TB_END = 1 << 6,
/*
* Flag: Permit a register definition to override a previous definition
* for the same (cp, is64, crn, crm, opc1, opc2) tuple: either the new
* or the old must have the ARM_CP_OVERRIDE bit set.
*/
ARM_CP_OVERRIDE = 1 << 7,
/*
* Flag: Register is an alias view of some underlying state which is also
* visible via another register, and that the other register is handling
* migration and reset; registers marked ARM_CP_ALIAS will not be migrated
* but may have their state set by syncing of register state from KVM.
*/
ARM_CP_ALIAS = 1 << 8,
/*
* Flag: Register does I/O and therefore its accesses need to be marked
* with gen_io_start() and also end the TB. In particular, registers which
* implement clocks or timers require this.
*/
ARM_CP_IO = 1 << 9,
/*
* Flag: Register has no underlying state and does not support raw access
* for state saving/loading; it will not be used for either migration or
* KVM state synchronization. Typically this is for "registers" which are
* actually used as instructions for cache maintenance and so on.
*/
ARM_CP_NO_RAW = 1 << 10,
/*
* Flag: The read or write hook might raise an exception; the generated
* code will synchronize the CPU state before calling the hook so that it
* is safe for the hook to call raise_exception().
*/
ARM_CP_RAISES_EXC = 1 << 11,
/*
* Flag: Writes to the sysreg might change the exception level - typically
* on older ARM chips. For those cases we need to re-read the new el when
* recomputing the translation flags.
*/
ARM_CP_NEWEL = 1 << 12,
/*
* Flag: Access check for this sysreg is identical to accessing FPU state
* from an instruction: use translation fp_access_check().
*/
ARM_CP_FPU = 1 << 13,
/*
* Flag: Access check for this sysreg is identical to accessing SVE state
* from an instruction: use translation sve_access_check().
*/
ARM_CP_SVE = 1 << 14,
/* Flag: Do not expose in gdb sysreg xml. */
ARM_CP_NO_GDB = 1 << 15,
};
/*
* Valid values for ARMCPRegInfo state field, indicating which of

4
target/arm/cpu.c
View File

@ -117,7 +117,7 @@ static void cp_reg_reset(gpointer key, gpointer value, gpointer opaque)
ARMCPRegInfo *ri = value;
ARMCPU *cpu = opaque;
if (ri->type & (ARM_CP_SPECIAL | ARM_CP_ALIAS)) {
if (ri->type & (ARM_CP_SPECIAL_MASK | ARM_CP_ALIAS)) {
return;
}
@ -153,7 +153,7 @@ static void cp_reg_check_reset(gpointer key, gpointer value, gpointer opaque)
ARMCPU *cpu = opaque;
uint64_t oldvalue, newvalue;
if (ri->type & (ARM_CP_SPECIAL | ARM_CP_ALIAS | ARM_CP_NO_RAW)) {
if (ri->type & (ARM_CP_SPECIAL_MASK | ARM_CP_ALIAS | ARM_CP_NO_RAW)) {
return;
}

4
target/arm/helper.c
View File

@ -8600,7 +8600,7 @@ static void add_cpreg_to_hashtable(ARMCPU *cpu, const ARMCPRegInfo *r,
* multiple times. Special registers (ie NOP/WFI) are
* never migratable and not even raw-accessible.
*/
if ((r->type & ARM_CP_SPECIAL)) {
if (r->type & ARM_CP_SPECIAL_MASK) {
r2->type |= ARM_CP_NO_RAW;
}
if (((r->crm == CP_ANY) && crm != 0) ||
@ -8750,7 +8750,7 @@ void define_one_arm_cp_reg_with_opaque(ARMCPU *cpu,
/* Check that the register definition has enough info to handle
* reads and writes if they are permitted.
*/
if (!(r->type & (ARM_CP_SPECIAL|ARM_CP_CONST))) {
if (!(r->type & (ARM_CP_SPECIAL_MASK | ARM_CP_CONST))) {
if (r->access & PL3_R) {
assert((r->fieldoffset ||
(r->bank_fieldoffsets[0] && r->bank_fieldoffsets[1])) ||

6
target/arm/translate-a64.c
View File

@ -1833,7 +1833,9 @@ static void handle_sys(DisasContext *s, uint32_t insn, bool isread,
}
/* Handle special cases first */
switch (ri->type & ~(ARM_CP_FLAG_MASK & ~ARM_CP_SPECIAL)) {
switch (ri->type & ARM_CP_SPECIAL_MASK) {
case 0:
break;
case ARM_CP_NOP:
return;
case ARM_CP_NZCV:
@ -1908,7 +1910,7 @@ static void handle_sys(DisasContext *s, uint32_t insn, bool isread,
}
return;
default:
break;
g_assert_not_reached();
}
if ((ri->type & ARM_CP_FPU) && !fp_access_check(s)) {
return;

6
target/arm/translate.c
View File

@ -4744,7 +4744,9 @@ static void do_coproc_insn(DisasContext *s, int cpnum, int is64,
}
/* Handle special cases first */
switch (ri->type & ~(ARM_CP_FLAG_MASK & ~ARM_CP_SPECIAL)) {
switch (ri->type & ARM_CP_SPECIAL_MASK) {
case 0:
break;
case ARM_CP_NOP:
return;
case ARM_CP_WFI:
@ -4756,7 +4758,7 @@ static void do_coproc_insn(DisasContext *s, int cpnum, int is64,
s->base.is_jmp = DISAS_WFI;
return;
default:
break;
g_assert_not_reached();
}
if ((tb_cflags(s->base.tb) & CF_USE_ICOUNT) && (ri->type & ARM_CP_IO)) {