diff options
Diffstat (limited to 'isa/rv64mi/pmpaddr.S')
| -rw-r--r-- | isa/rv64mi/pmpaddr.S | 154 |
1 files changed, 154 insertions, 0 deletions
diff --git a/isa/rv64mi/pmpaddr.S b/isa/rv64mi/pmpaddr.S new file mode 100644 index 0000000..29413af --- /dev/null +++ b/isa/rv64mi/pmpaddr.S @@ -0,0 +1,154 @@ +# See LICENSE for license details. + +#***************************************************************************** +# pmpaddr.S +#----------------------------------------------------------------------------- +# +# Test edge cases around the pmpaddr[G-1] bit which sometimes reads as zero +# but is always writable and retains its state. Also test CSRC and CSRS +# modifications to other bits result in a correct read-modify-write. +# +# This test auto-detects G but assumes PMP is available. It supports a +# maximum G of XLEN-1. There's no minimum but if G is 0 then the G-1 bit +# does not exist and this test trivially passes. + +#include "riscv_test.h" +#include "test_macros.h" + +RVTEST_RV64M +RVTEST_CODE_BEGIN + + li TESTNUM, 1 + + # Software may determine the PMP granularity by writing zero to pmpcfg0, + # then writing all ones to pmpaddr0, then reading back pmpaddr0. + # If G is the index of the least-significant bit set, the PMP granularity + # is 2^(G+2) bytes. + csrw pmpcfg0, zero + li t0, -1 + csrw pmpaddr0, t0 + csrr t0, pmpaddr0 + + # Isolate the least significant bit. + + neg t1, t0 + and a7, t0, t1 + + # a7 now contains only the lowest 1 that was set in pmpaddr0. + + # If a7 is 0 then G is >=XLEN which this test does not support. + beqz a7, fail + # Shift so the G-1 bit is set. + srl a7, a7, 1 + # If no bits are set now then G is 0, which trivially passes. + beqz a7, pass + +#define PMPADDR_Gm1_MASK a7 +#define PMPCFG_A_MASK (0x3 << 3) + # Ok now we can begin the main test! + +# Set pmpaddr0[G-1] to `value` (1 or 0). +.macro set_pmpaddr_bit value +.if \value + csrs pmpaddr0, PMPADDR_Gm1_MASK +.else + csrc pmpaddr0, PMPADDR_Gm1_MASK +.endif +.endm + +# Switch pmpcfg0 to OFF mode so pmpaddr0[G-1] reads as 0. +.macro set_mode_off + csrc pmpcfg0, PMPCFG_A_MASK +.endm + +# Switch pmpcfg0 to NAPOT mode so pmpaddr0[G-1] reads normally. +.macro set_mode_napot + csrs pmpcfg0, PMPCFG_A_MASK +.endm + +# Check that pmpaddr9[G] is set or unset depending on expected_value. +.macro check_pmpaddr_bit expected_value + # Note when gas 2.43 is common we can use \+ instead of \@ which + # gives more sensible numbers. \@ still works but it gives 4, 6, + # 8, 10, 15... instead of 0, 1, 2, 3. + li TESTNUM, (2 + \@) + csrr t6, pmpaddr0 + and t6, t6, PMPADDR_Gm1_MASK +.if \expected_value + beqz t6, fail +.else + bnez t6, fail +.endif +.endm + +.macro check_pmpaddr_bit_clear + csrr t6, pmpaddr0 + and t6, t6, PMPADDR_Gm1_MASK + bnez t6, fail +.endm + + # Initialise pmpaddr and pmpcfg. + + # M bit is writable in NAPOT mode. + set_mode_napot + # Clear it, it should read 0. + set_pmpaddr_bit 0 + check_pmpaddr_bit 0 + # Set it, it shouldn't read 0. + set_pmpaddr_bit 1 + check_pmpaddr_bit 1 + # M bit is writable but reads as 0 in OFF mode. + set_mode_off + # Should read as 0. + check_pmpaddr_bit 0 + # Switch back to NAPOT. The 1 should be readable again. + set_mode_napot + check_pmpaddr_bit 1 + + # Test writing the bit while it is read-as-zero. + set_pmpaddr_bit 0 + set_mode_off + set_pmpaddr_bit 1 + set_mode_napot + check_pmpaddr_bit 1 + + # Test modifying a *different* bit while its underlying + # value is 1 but it reads as 0. Since csrs and csrc are + # read-modify-write they reads-as value will be written + # to the underlying value. + set_mode_off + # A csrs or csrc from the zero register does not have + # any side effects. + csrc pmpaddr0, zero + csrs pmpaddr0, zero + set_mode_napot + check_pmpaddr_bit 1 + + set_mode_off + # Set other bits. This should result in M being cleared + # since it currently reads as 0. + not t0, PMPADDR_Gm1_MASK + csrs pmpaddr0, t0 + set_mode_napot + check_pmpaddr_bit 0 + + j pass + + TEST_PASSFAIL + + .align 2 + .global mtvec_handler +mtvec_handler: + # We aren't expecting any exceptions unless PMP is not supported + # in which case this test is also not supported. There's no + # way to probe for PMP support so we can't just pass in this case. + j fail + +RVTEST_CODE_END + + .data +RVTEST_DATA_BEGIN + + TEST_DATA + +RVTEST_DATA_END |