From a7767265f4046828b588cfc5eeada1b69105efea Mon Sep 17 00:00:00 2001 From: Luke Kenneth Casson Leighton Date: Sun, 14 Apr 2019 07:24:26 +0100 Subject: [PATCH] experimental conversion of ptw.sv --- TLB/src/ariane/ptw.py | 63 ++++++++++++++++++++++--------------------- 1 file changed, 32 insertions(+), 31 deletions(-) diff --git a/TLB/src/ariane/ptw.py b/TLB/src/ariane/ptw.py index 0564b6e1..8faea2ed 100644 --- a/TLB/src/ariane/ptw.py +++ b/TLB/src/ariane/ptw.py @@ -316,42 +316,43 @@ class PTW: # check if the ppn is correctly aligned: # 6. If i > 0 and pa.ppn[i − 1 : 0] != 0, this is a misaligned superpage; stop and raise a page-fault # exception. - if (ptw_lvl_q == LVL1 && pte.ppn[17:0] != '0) begin - state_d = PROPAGATE_ERROR; - dtlb_update_o.valid = 1'b0; - itlb_update_o.valid = 1'b0; - end else if (ptw_lvl_q == LVL2 && pte.ppn[8:0] != '0) begin - state_d = PROPAGATE_ERROR; - dtlb_update_o.valid = 1'b0; - itlb_update_o.valid = 1'b0; - end + l1err = Signal() + l2err = Signal() + m.d.comb += [l2err.eq((ptw_lvl_q == LVL2) & \ + pte.ppn[0:9] != Const(0, 9)), + l1err.eq((ptw_lvl_q == LVL1) & \ + pte.ppn[0:18] != Const(0, 18)) + ] + with m.If(l1err | l2err): + m.next = "PROPAGATE_ERROR" + m.d.comb += [dtlb_update_o.valid.eq(0), + itlb_update_o.valid.eq(0)] + # this is a pointer to the next TLB level - end else begin + with m.Else(): # pointer to next level of page table - if (ptw_lvl_q == LVL1) begin + with m.If (ptw_lvl_q == LVL1): # we are in the second level now - ptw_lvl_n = LVL2; - ptw_pptr_n = {pte.ppn, vaddr_q[29:21], 3'b0}; - end - - if (ptw_lvl_q == LVL2) begin + pptr = Cat(Const(0, 3), dtlb_vaddr_i[21:30], + pte.ppn) + m.d.comb += [ptw_lvl_n.eq(LVL2), + ptw_pptr_n.eq(pptr) + ] + with m.If(ptw_lvl_q == LVL2): # here we received a pointer to the third level - ptw_lvl_n = LVL3; - ptw_pptr_n = {pte.ppn, vaddr_q[20:12], 3'b0}; - end - - state_d = WAIT_GRANT; - - if (ptw_lvl_q == LVL3) begin - # Should already be the last level page table => Error - ptw_lvl_n = LVL3; - state_d = PROPAGATE_ERROR; - end - end - end - end + pptr = Cat(Const(0, 3), dtlb_vaddr_i[12:21], + pte.ppn) + m.d.comb += [ptw_lvl_n.eq(LVL3), + ptw_pptr_n.eq(pptr) + ] + m.next = "WAIT_GRANT" + + with m.If (ptw_lvl_q == LVL3): + # Should already be the last level page table => Error + m.d.comb += [ptw_lvl_n.eq(LVL3), + m.next = "PROPAGATE_ERROR" # we've got a data WAIT_GRANT so tell the cache that the tag is valid - end + # Propagate error to MMU/LSU PROPAGATE_ERROR: begin state_d = IDLE; -- 2.30.2