There is an overflow with the current code where a pmpaddr value of
0x1fffffff is decoded as sa=0 and ea=0 whereas it should be sa=0 and
ea=0xffffffff.
Fix that by simplifying the computation. There is in fact no need for
ctz64() nor special case for -1 to achieve proper results.
Signed-off-by: Nicolas Pitre <nico@fluxnic.net>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <rq81o86n-17ps-92no-p65o-79o88476266@syhkavp.arg>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
0111...1111 2^(XLEN+2)-byte NAPOT range
1111...1111 Reserved
*/
- if (a == -1) {
- *sa = 0u;
- *ea = -1;
- return;
- } else {
- target_ulong t1 = ctz64(~a);
- target_ulong base = (a & ~(((target_ulong)1 << t1) - 1)) << 2;
- target_ulong range = ((target_ulong)1 << (t1 + 3)) - 1;
- *sa = base;
- *ea = base + range;
- }
+ a = (a << 2) | 0x3;
+ *sa = a & (a + 1);
+ *ea = a | (a + 1);
}
void pmp_update_rule_addr(CPURISCVState *env, uint32_t pmp_index)