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qemu-e2k/target/arm/cpregs.h

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/*
* QEMU ARM CP Register access and descriptions
*
* Copyright (c) 2022 Linaro Ltd
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see
* <http://www.gnu.org/licenses/gpl-2.0.html>
*/
#ifndef TARGET_ARM_CPREGS_H
#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.
*/
#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
/*
* Valid values for ARMCPRegInfo state field, indicating which of
* the AArch32 and AArch64 execution states this register is visible in.
* If the reginfo doesn't explicitly specify then it is AArch32 only.
* If the reginfo is declared to be visible in both states then a second
* reginfo is synthesised for the AArch32 view of the AArch64 register,
* such that the AArch32 view is the lower 32 bits of the AArch64 one.
* Note that we rely on the values of these enums as we iterate through
* the various states in some places.
*/
enum {
ARM_CP_STATE_AA32 = 0,
ARM_CP_STATE_AA64 = 1,
ARM_CP_STATE_BOTH = 2,
};
/*
* ARM CP register secure state flags. These flags identify security state
* attributes for a given CP register entry.
* The existence of both or neither secure and non-secure flags indicates that
* the register has both a secure and non-secure hash entry. A single one of
* these flags causes the register to only be hashed for the specified
* security state.
* Although definitions may have any combination of the S/NS bits, each
* registered entry will only have one to identify whether the entry is secure
* or non-secure.
*/
enum {
ARM_CP_SECSTATE_S = (1 << 0), /* bit[0]: Secure state register */
ARM_CP_SECSTATE_NS = (1 << 1), /* bit[1]: Non-secure state register */
};
/*
* Access rights:
* We define bits for Read and Write access for what rev C of the v7-AR ARM ARM
* defines as PL0 (user), PL1 (fiq/irq/svc/abt/und/sys, ie privileged), and
* PL2 (hyp). The other level which has Read and Write bits is Secure PL1
* (ie any of the privileged modes in Secure state, or Monitor mode).
* If a register is accessible in one privilege level it's always accessible
* in higher privilege levels too. Since "Secure PL1" also follows this rule
* (ie anything visible in PL2 is visible in S-PL1, some things are only
* visible in S-PL1) but "Secure PL1" is a bit of a mouthful, we bend the
* terminology a little and call this PL3.
* In AArch64 things are somewhat simpler as the PLx bits line up exactly
* with the ELx exception levels.
*
* If access permissions for a register are more complex than can be
* described with these bits, then use a laxer set of restrictions, and
* do the more restrictive/complex check inside a helper function.
*/
#define PL3_R 0x80
#define PL3_W 0x40
#define PL2_R (0x20 | PL3_R)
#define PL2_W (0x10 | PL3_W)
#define PL1_R (0x08 | PL2_R)
#define PL1_W (0x04 | PL2_W)
#define PL0_R (0x02 | PL1_R)
#define PL0_W (0x01 | PL1_W)
/*
* For user-mode some registers are accessible to EL0 via a kernel
* trap-and-emulate ABI. In this case we define the read permissions
* as actually being PL0_R. However some bits of any given register
* may still be masked.
*/
#ifdef CONFIG_USER_ONLY
#define PL0U_R PL0_R
#else
#define PL0U_R PL1_R
#endif
#define PL3_RW (PL3_R | PL3_W)
#define PL2_RW (PL2_R | PL2_W)
#define PL1_RW (PL1_R | PL1_W)
#define PL0_RW (PL0_R | PL0_W)
typedef enum CPAccessResult {
/* Access is permitted */
CP_ACCESS_OK = 0,
/*
* Combined with one of the following, the low 2 bits indicate the
* target exception level. If 0, the exception is taken to the usual
* target EL (EL1 or PL1 if in EL0, otherwise to the current EL).
*/
CP_ACCESS_EL_MASK = 3,
/*
* Access fails due to a configurable trap or enable which would
* result in a categorized exception syndrome giving information about
* the failing instruction (ie syndrome category 0x3, 0x4, 0x5, 0x6,
* 0xc or 0x18).
*/
CP_ACCESS_TRAP = (1 << 2),
CP_ACCESS_TRAP_EL2 = CP_ACCESS_TRAP | 2,
CP_ACCESS_TRAP_EL3 = CP_ACCESS_TRAP | 3,
/*
* Access fails and results in an exception syndrome 0x0 ("uncategorized").
* Note that this is not a catch-all case -- the set of cases which may
* result in this failure is specifically defined by the architecture.
*/
CP_ACCESS_TRAP_UNCATEGORIZED = (2 << 2),
CP_ACCESS_TRAP_UNCATEGORIZED_EL2 = CP_ACCESS_TRAP_UNCATEGORIZED | 2,
CP_ACCESS_TRAP_UNCATEGORIZED_EL3 = CP_ACCESS_TRAP_UNCATEGORIZED | 3,
} CPAccessResult;
typedef struct ARMCPRegInfo ARMCPRegInfo;
/*
* Access functions for coprocessor registers. These cannot fail and
* may not raise exceptions.
*/
typedef uint64_t CPReadFn(CPUARMState *env, const ARMCPRegInfo *opaque);
typedef void CPWriteFn(CPUARMState *env, const ARMCPRegInfo *opaque,
uint64_t value);
/* Access permission check functions for coprocessor registers. */
typedef CPAccessResult CPAccessFn(CPUARMState *env,
const ARMCPRegInfo *opaque,
bool isread);
/* Hook function for register reset */
typedef void CPResetFn(CPUARMState *env, const ARMCPRegInfo *opaque);
#define CP_ANY 0xff
/* Definition of an ARM coprocessor register */
struct ARMCPRegInfo {
/* Name of register (useful mainly for debugging, need not be unique) */
const char *name;
/*
* Location of register: coprocessor number and (crn,crm,opc1,opc2)
* tuple. Any of crm, opc1 and opc2 may be CP_ANY to indicate a
* 'wildcard' field -- any value of that field in the MRC/MCR insn
* will be decoded to this register. The register read and write
* callbacks will be passed an ARMCPRegInfo with the crn/crm/opc1/opc2
* used by the program, so it is possible to register a wildcard and
* then behave differently on read/write if necessary.
* For 64 bit registers, only crm and opc1 are relevant; crn and opc2
* must both be zero.
* For AArch64-visible registers, opc0 is also used.
* Since there are no "coprocessors" in AArch64, cp is purely used as a
* way to distinguish (for KVM's benefit) guest-visible system registers
* from demuxed ones provided to preserve the "no side effects on
* KVM register read/write from QEMU" semantics. cp==0x13 is guest
* visible (to match KVM's encoding); cp==0 will be converted to
* cp==0x13 when the ARMCPRegInfo is registered, for convenience.
*/
uint8_t cp;
uint8_t crn;
uint8_t crm;
uint8_t opc0;
uint8_t opc1;
uint8_t opc2;
/* Execution state in which this register is visible: ARM_CP_STATE_* */
int state;
/* Register type: ARM_CP_* bits/values */
int type;
/* Access rights: PL*_[RW] */
int access;
/* Security state: ARM_CP_SECSTATE_* bits/values */
int secure;
/*
* The opaque pointer passed to define_arm_cp_regs_with_opaque() when
* this register was defined: can be used to hand data through to the
* register read/write functions, since they are passed the ARMCPRegInfo*.
*/
void *opaque;
/*
* Value of this register, if it is ARM_CP_CONST. Otherwise, if
* fieldoffset is non-zero, the reset value of the register.
*/
uint64_t resetvalue;
/*
* Offset of the field in CPUARMState for this register.
* This is not needed if either:
* 1. type is ARM_CP_CONST or one of the ARM_CP_SPECIALs
* 2. both readfn and writefn are specified
*/
ptrdiff_t fieldoffset; /* offsetof(CPUARMState, field) */
/*
* Offsets of the secure and non-secure fields in CPUARMState for the
* register if it is banked. These fields are only used during the static
* registration of a register. During hashing the bank associated
* with a given security state is copied to fieldoffset which is used from
* there on out.
*
* It is expected that register definitions use either fieldoffset or
* bank_fieldoffsets in the definition but not both. It is also expected
* that both bank offsets are set when defining a banked register. This
* use indicates that a register is banked.
*/
ptrdiff_t bank_fieldoffsets[2];
/*
* Function for making any access checks for this register in addition to
* those specified by the 'access' permissions bits. If NULL, no extra
* checks required. The access check is performed at runtime, not at
* translate time.
*/
CPAccessFn *accessfn;
/*
* Function for handling reads of this register. If NULL, then reads
* will be done by loading from the offset into CPUARMState specified
* by fieldoffset.
*/
CPReadFn *readfn;
/*
* Function for handling writes of this register. If NULL, then writes
* will be done by writing to the offset into CPUARMState specified
* by fieldoffset.
*/
CPWriteFn *writefn;
/*
* Function for doing a "raw" read; used when we need to copy
* coprocessor state to the kernel for KVM or out for
* migration. This only needs to be provided if there is also a
* readfn and it has side effects (for instance clear-on-read bits).
*/
CPReadFn *raw_readfn;
/*
* Function for doing a "raw" write; used when we need to copy KVM
* kernel coprocessor state into userspace, or for inbound
* migration. This only needs to be provided if there is also a
* writefn and it masks out "unwritable" bits or has write-one-to-clear
* or similar behaviour.
*/
CPWriteFn *raw_writefn;
/*
* Function for resetting the register. If NULL, then reset will be done
* by writing resetvalue to the field specified in fieldoffset. If
* fieldoffset is 0 then no reset will be done.
*/
CPResetFn *resetfn;
/*
* "Original" writefn and readfn.
* For ARMv8.1-VHE register aliases, we overwrite the read/write
* accessor functions of various EL1/EL0 to perform the runtime
* check for which sysreg should actually be modified, and then
* forwards the operation. Before overwriting the accessors,
* the original function is copied here, so that accesses that
* really do go to the EL1/EL0 version proceed normally.
* (The corresponding EL2 register is linked via opaque.)
*/
CPReadFn *orig_readfn;
CPWriteFn *orig_writefn;
};
/*
* Macros which are lvalues for the field in CPUARMState for the
* ARMCPRegInfo *ri.
*/
#define CPREG_FIELD32(env, ri) \
(*(uint32_t *)((char *)(env) + (ri)->fieldoffset))
#define CPREG_FIELD64(env, ri) \
(*(uint64_t *)((char *)(env) + (ri)->fieldoffset))
void define_one_arm_cp_reg_with_opaque(ARMCPU *cpu, const ARMCPRegInfo *reg,
void *opaque);
static inline void define_one_arm_cp_reg(ARMCPU *cpu, const ARMCPRegInfo *regs)
{
define_one_arm_cp_reg_with_opaque(cpu, regs, NULL);
}
void define_arm_cp_regs_with_opaque_len(ARMCPU *cpu, const ARMCPRegInfo *regs,
void *opaque, size_t len);
#define define_arm_cp_regs_with_opaque(CPU, REGS, OPAQUE) \
do { \
QEMU_BUILD_BUG_ON(ARRAY_SIZE(REGS) == 0); \
define_arm_cp_regs_with_opaque_len(CPU, REGS, OPAQUE, \
ARRAY_SIZE(REGS)); \
} while (0)
#define define_arm_cp_regs(CPU, REGS) \
define_arm_cp_regs_with_opaque(CPU, REGS, NULL)
const ARMCPRegInfo *get_arm_cp_reginfo(GHashTable *cpregs, uint32_t encoded_cp);
/*
* Definition of an ARM co-processor register as viewed from
* userspace. This is used for presenting sanitised versions of
* registers to userspace when emulating the Linux AArch64 CPU
* ID/feature ABI (advertised as HWCAP_CPUID).
*/
typedef struct ARMCPRegUserSpaceInfo {
/* Name of register */
const char *name;
/* Is the name actually a glob pattern */
bool is_glob;
/* Only some bits are exported to user space */
uint64_t exported_bits;
/* Fixed bits are applied after the mask */
uint64_t fixed_bits;
} ARMCPRegUserSpaceInfo;
void modify_arm_cp_regs_with_len(ARMCPRegInfo *regs, size_t regs_len,
const ARMCPRegUserSpaceInfo *mods,
size_t mods_len);
#define modify_arm_cp_regs(REGS, MODS) \
do { \
QEMU_BUILD_BUG_ON(ARRAY_SIZE(REGS) == 0); \
QEMU_BUILD_BUG_ON(ARRAY_SIZE(MODS) == 0); \
modify_arm_cp_regs_with_len(REGS, ARRAY_SIZE(REGS), \
MODS, ARRAY_SIZE(MODS)); \
} while (0)
/* CPWriteFn that can be used to implement writes-ignored behaviour */
void arm_cp_write_ignore(CPUARMState *env, const ARMCPRegInfo *ri,
uint64_t value);
/* CPReadFn that can be used for read-as-zero behaviour */
uint64_t arm_cp_read_zero(CPUARMState *env, const ARMCPRegInfo *ri);
/*
* CPResetFn that does nothing, for use if no reset is required even
* if fieldoffset is non zero.
*/
void arm_cp_reset_ignore(CPUARMState *env, const ARMCPRegInfo *opaque);
/*
* Return true if this reginfo struct's field in the cpu state struct
* is 64 bits wide.
*/
static inline bool cpreg_field_is_64bit(const ARMCPRegInfo *ri)
{
return (ri->state == ARM_CP_STATE_AA64) || (ri->type & ARM_CP_64BIT);
}
static inline bool cp_access_ok(int current_el,
const ARMCPRegInfo *ri, int isread)
{
return (ri->access >> ((current_el * 2) + isread)) & 1;
}
/* Raw read of a coprocessor register (as needed for migration, etc) */
uint64_t read_raw_cp_reg(CPUARMState *env, const ARMCPRegInfo *ri);
#endif /* TARGET_ARM_CPREGS_H */
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