/*
* ARM TLB (Translation lookaside buffer) helpers.
*
* This code is licensed under the GNU GPL v2 or later.
*
* SPDX-License-Identifier: GPL-2.0-or-later
*/
#include "qemu/osdep.h"
#include "cpu.h"
#include "internals.h"
#include "exec/exec-all.h"
#include "exec/helper-proto.h"
/* Return true if the translation regime is using LPAE format page tables */
bool regime_using_lpae_format(CPUARMState *env, ARMMMUIdx mmu_idx)
{
int el = regime_el(env, mmu_idx);
if (el == 2 || arm_el_is_aa64(env, el)) {
return true;
}
if (arm_feature(env, ARM_FEATURE_LPAE)
&& (regime_tcr(env, mmu_idx) & TTBCR_EAE)) {
return true;
}
return false;
}
/*
* Returns true if the stage 1 translation regime is using LPAE format page
* tables. Used when raising alignment exceptions, whose FSR changes depending
* on whether the long or short descriptor format is in use.
*/
bool arm_s1_regime_using_lpae_format(CPUARMState *env, ARMMMUIdx mmu_idx)
{
mmu_idx = stage_1_mmu_idx(mmu_idx);
return regime_using_lpae_format(env, mmu_idx);
}
static inline uint32_t merge_syn_data_abort(uint32_t template_syn,
unsigned int target_el,
bool same_el, bool ea,
bool s1ptw, bool is_write,
int fsc)
{
uint32_t syn;
/*
* ISV is only set for data aborts routed to EL2 and
* never for stage-1 page table walks faulting on stage 2.
*
* Furthermore, ISV is only set for certain kinds of load/stores.
* If the template syndrome does not have ISV set, we should leave
* it cleared.
*
* See ARMv8 specs, D7-1974:
* ISS encoding for an exception from a Data Abort, the
* ISV field.
*/
if (!(template_syn & ARM_EL_ISV) || target_el != 2 || s1ptw) {
syn = syn_data_abort_no_iss(same_el, 0,
ea, 0, s1ptw, is_write, fsc);
} else {
/*
* Fields: IL, ISV, SAS, SSE, SRT, SF and AR come from the template
* syndrome created at translation time.
* Now we create the runtime syndrome with the remaining fields.
*/
syn = syn_data_abort_with_iss(same_el,
0, 0, 0, 0, 0,
ea, 0, s1ptw, is_write, fsc,
true);
/* Merge the runtime syndrome with the template syndrome. */
syn |= template_syn;
}
return syn;
}
static uint32_t compute_fsr_fsc(CPUARMState *env, ARMMMUFaultInfo *fi,
int target_el, int mmu_idx, uint32_t *ret_fsc)
{
ARMMMUIdx arm_mmu_idx = core_to_arm_mmu_idx(env, mmu_idx);
uint32_t fsr, fsc;
if (target_el == 2 || arm_el_is_aa64(env, target_el) ||
arm_s1_regime_using_lpae_format(env, arm_mmu_idx)) {
/*
* LPAE format fault status register : bottom 6 bits are
* status code in the same form as needed for syndrome
*/
fsr = arm_fi_to_lfsc(fi);
fsc = extract32(fsr, 0, 6);
} else {
fsr = arm_fi_to_sfsc(fi);
/*
* Short format FSR : this fault will never actually be reported
* to an EL that uses a syndrome register. Use a (currently)
* reserved FSR code in case the constructed syndrome does leak
* into the guest somehow.
*/
fsc = 0x3f;
}
*ret_fsc = fsc;
return fsr;
}
static G_NORETURN
void arm_deliver_fault(ARMCPU *cpu, vaddr addr,
MMUAccessType access_type,
int mmu_idx, ARMMMUFaultInfo *fi)
{
CPUARMState *env = &cpu->env;
int target_el;
bool same_el;
uint32_t syn, exc, fsr, fsc;
target_el = exception_target_el(env);
if (fi->stage2) {
target_el = 2;
env->cp15.hpfar_el2 = extract64(fi->s2addr, 12, 47) << 4;
if (arm_is_secure_below_el3(env) && fi->s1ns) {
env->cp15.hpfar_el2 |= HPFAR_NS;
}
}
same_el = (arm_current_el(env) == target_el);
fsr = compute_fsr_fsc(env, fi, target_el, mmu_idx, &fsc);
if (access_type == MMU_INST_FETCH) {
syn = syn_insn_abort(same_el, fi->ea, fi->s1ptw, fsc);
exc = EXCP_PREFETCH_ABORT;
} else {
syn = merge_syn_data_abort(env->exception.syndrome, target_el,
same_el, fi->ea, fi->s1ptw,
access_type == MMU_DATA_STORE,
fsc);
if (access_type == MMU_DATA_STORE
&& arm_feature(env, ARM_FEATURE_V6)) {
fsr |= (1 << 11);
}
exc = EXCP_DATA_ABORT;
}
env->exception.vaddress = addr;
env->exception.fsr = fsr;
raise_exception(env, exc, syn, target_el);
}
/* Raise a data fault alignment exception for the specified virtual address */
void arm_cpu_do_unaligned_access(CPUState *cs, vaddr vaddr,
MMUAccessType access_type,
int mmu_idx, uintptr_t retaddr)
{
ARMCPU *cpu = ARM_CPU(cs);
ARMMMUFaultInfo fi = {};
/* now we have a real cpu fault */
cpu_restore_state(cs, retaddr, true);
fi.type = ARMFault_Alignment;
arm_deliver_fault(cpu, vaddr, access_type, mmu_idx, &fi);
}
void helper_exception_pc_alignment(CPUARMState *env, target_ulong pc)
{
ARMMMUFaultInfo fi = { .type = ARMFault_Alignment };
int target_el = exception_target_el(env);
int mmu_idx = cpu_mmu_index(env, true);
uint32_t fsc;
env->exception.vaddress = pc;
/*
* Note that the fsc is not applicable to this exception,
* since any syndrome is pcalignment not insn_abort.
*/
env->exception.fsr = compute_fsr_fsc(env, &fi, target_el, mmu_idx, &fsc);
raise_exception(env, EXCP_PREFETCH_ABORT, syn_pcalignment(), target_el);
}
#if !defined(CONFIG_USER_ONLY)
/*
* arm_cpu_do_transaction_failed: handle a memory system error response
* (eg "no device/memory present at address") by raising an external abort
* exception
*/
void arm_cpu_do_transaction_failed(CPUState *cs, hwaddr physaddr,
vaddr addr, unsigned size,
MMUAccessType access_type,
int mmu_idx, MemTxAttrs attrs,
MemTxResult response, uintptr_t retaddr)
{
ARMCPU *cpu = ARM_CPU(cs);
ARMMMUFaultInfo fi = {};
/* now we have a real cpu fault */
cpu_restore_state(cs, retaddr, true);
fi.ea = arm_extabort_type(response);
fi.type = ARMFault_SyncExternal;
arm_deliver_fault(cpu, addr, access_type, mmu_idx, &fi);
}
bool arm_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
MMUAccessType access_type, int mmu_idx,
bool probe, uintptr_t retaddr)
{
ARMCPU *cpu = ARM_CPU(cs);
ARMMMUFaultInfo fi = {};
GetPhysAddrResult res = {};
int ret;
/*
* Walk the page table and (if the mapping exists) add the page
* to the TLB. On success, return true. Otherwise, if probing,
* return false. Otherwise populate fsr with ARM DFSR/IFSR fault
* register format, and signal the fault.
*/
ret = get_phys_addr(&cpu->env, address, access_type,
core_to_arm_mmu_idx(&cpu->env, mmu_idx),
&res, &fi);
if (likely(!ret)) {
/*
* Map a single [sub]page. Regions smaller than our declared
* target page size are handled specially, so for those we
* pass in the exact addresses.
*/
if (res.f.lg_page_size >= TARGET_PAGE_BITS) {
res.f.phys_addr &= TARGET_PAGE_MASK;
address &= TARGET_PAGE_MASK;
}
/* Notice and record tagged memory. */
if (cpu_isar_feature(aa64_mte, cpu) && res.cacheattrs.attrs == 0xf0) {
arm_tlb_mte_tagged(&res.f.attrs) = true;
}
tlb_set_page_full(cs, mmu_idx, address, &res.f);
return true;
} else if (probe) {
return false;
} else {
/* now we have a real cpu fault */
cpu_restore_state(cs, retaddr, true);
arm_deliver_fault(cpu, address, access_type, mmu_idx, &fi);
}
}
#else
void arm_cpu_record_sigsegv(CPUState *cs, vaddr addr,
MMUAccessType access_type,
bool maperr, uintptr_t ra)
{
ARMMMUFaultInfo fi = {
.type = maperr ? ARMFault_Translation : ARMFault_Permission,
.level = 3,
};
ARMCPU *cpu = ARM_CPU(cs);
/*
* We report both ESR and FAR to signal handlers.
* For now, it's easiest to deliver the fault normally.
*/
cpu_restore_state(cs, ra, true);
arm_deliver_fault(cpu, addr, access_type, MMU_USER_IDX, &fi);
}
void arm_cpu_record_sigbus(CPUState *cs, vaddr addr,
MMUAccessType access_type, uintptr_t ra)
{
arm_cpu_do_unaligned_access(cs, addr, access_type, MMU_USER_IDX, ra);
}
#endif /* !defined(CONFIG_USER_ONLY) */
