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rvcpp: fix up PMP address mask for all-ones pmpaddr, and raise instruction fault on instruction stradding two PMP regions, like the hardware

This commit is contained in:
Luke Wren 2024-04-27 19:34:17 +01:00
parent 7d370292b0
commit ebe5a44454
3 changed files with 33 additions and 13 deletions
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3
test/sim/rvcpp/include/rv_csr.h
View File

@ -127,5 +127,8 @@ public:
return mcause; return mcause;
} }
// Return region, or -1 for no match
int get_pmp_match(ux_t addr);
uint get_pmp_xwr(ux_t addr); uint get_pmp_xwr(ux_t addr);
}; };

7
test/sim/rvcpp/rv_core.cpp
View File

@ -143,10 +143,15 @@ void RVCore::step(bool trace) {
uint funct3 = instr >> 12 & 0x7; uint funct3 = instr >> 12 & 0x7;
uint funct7 = instr >> 25 & 0x7f; uint funct7 = instr >> 25 & 0x7f;
bool pmp_straddle = false;
if (fetch0 && (*fetch0 & 0x3) == 0x3) {
pmp_straddle = csr.get_pmp_match(pc) != csr.get_pmp_match(pc + 2);
}
std::optional<ux_t> irq_target_pc = csr.trap_check_enter_irq(pc); std::optional<ux_t> irq_target_pc = csr.trap_check_enter_irq(pc);
if (irq_target_pc) { if (irq_target_pc) {
// Replace current instruction with IRQ entry // Replace current instruction with IRQ entry
} else if (!fetch0 || ((*fetch0 & 0x3) == 0x3 && !fetch1)) { } else if (!fetch0 || ((*fetch0 & 0x3) == 0x3 && (!fetch1 || pmp_straddle))) {
exception_cause = XCAUSE_INSTR_FAULT; exception_cause = XCAUSE_INSTR_FAULT;
} else if ((instr & 0x3) == 0x3) { } else if ((instr & 0x3) == 0x3) {
// 32-bit instruction // 32-bit instruction

38
test/sim/rvcpp/rv_csr.cpp
View File

@ -2,6 +2,7 @@
#include "encoding/rv_csr.h" #include "encoding/rv_csr.h"
#include <cassert> #include <cassert>
#include <cstdio>
// Inclusive msb:lsb style, like Verilog (and like the ISA manual) // Inclusive msb:lsb style, like Verilog (and like the ISA manual)
#define BITS_UPTO(msb) (~((-1u << (msb)) << 1)) #define BITS_UPTO(msb) (~((-1u << (msb)) << 1))
@ -251,26 +252,37 @@ ux_t RVCSR::trap_mret() {
return mepc; return mepc;
} }
uint RVCSR::get_pmp_xwr(ux_t addr) { int RVCSR::get_pmp_match(ux_t addr) {
bool match = false;
uint matching_xwr = 0;
uint matching_l = 0;
bool trace_pmp = get_true_priv() == PRV_U && true;
for (int i = 0; i < PMP_REGIONS; ++i) { for (int i = 0; i < PMP_REGIONS; ++i) {
if (pmpcfg_a(i) == 0u) { if (pmpcfg_a(i) == 0u) {
continue; continue;
} }
uint32_t mask = 0xffffffffu; ux_t mask = 0xffffffffu;
if (pmpcfg_a(i) == 2) { if (pmpcfg_a(i) == 3) {
if (pmpaddr[i] == 0xffffffffu) {
mask = 0u;
} else {
mask = 0xfffffffeu << __builtin_ctz(~pmpaddr[i]); mask = 0xfffffffeu << __builtin_ctz(~pmpaddr[i]);
} }
match = ((addr >> 2) & mask) == (pmpaddr[i] & mask);
if (match) {
matching_xwr = pmpcfg_xwr(i);
matching_l = pmpcfg_l(i);
// Lowest-numbered match determines success/failure:
break;
} }
bool match = ((addr >> 2) & mask) == (pmpaddr[i] & mask);
if (match) {
// Lowest-numbered match determines success/failure:
return i;
}
}
return -1;
}
uint RVCSR::get_pmp_xwr(ux_t addr) {
int region = get_pmp_match(addr);
bool match = false;
uint matching_xwr = 0;
uint matching_l = 0;
if (region >= 0) {
match = true;
matching_xwr = pmpcfg_xwr(region);
matching_l = pmpcfg_l(region);
} }
if (match) { if (match) {
// TODO MPRV // TODO MPRV