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-rw-r--r--rv64cpu/rtl/core/pmp_checker.sv181
1 files changed, 0 insertions, 181 deletions
diff --git a/rv64cpu/rtl/core/pmp_checker.sv b/rv64cpu/rtl/core/pmp_checker.sv
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@@ -1,181 +0,0 @@
-// Richard CPU
-// Copyright (C) 2026 Richard Qin
-
-// This program is free software: you can redistribute it and/or modify
-// it under the terms of the GNU General Public License as published by
-// the Free Software Foundation, either version 3 of the License, or
-// (at your option) any later version.
-
-// This program is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-// GNU General Public License for more details.
-
-// You should have received a copy of the GNU General Public License
-// along with this program. If not, see <https://www.gnu.org/licenses/>.
-
-// File path: rtl/core/pmp_checker.sv
-// Description: RISC-V Physical Memory Protection access checker.
-
-module pmp_checker
- import rv64_pkg::*;
- import csr_pkg::*;
-#(
- parameter int PHYS_ADDR_WIDTH = 56
-)(
- input logic req_valid,
- input logic [XLEN-1:0] req_paddr,
- input logic [3:0] req_size,
- input logic req_is_fetch,
- input logic req_is_store,
- input logic [1:0] priv_mode,
- input pmpcfg_entry_t pmpcfg_entries [PMP_ENTRY_COUNT],
- input pmpaddr_entry_t pmpaddr_entries [PMP_ENTRY_COUNT],
- output logic access_fault
-);
-
- localparam logic [1:0] PRIV_MODE_M = 2'b11;
-
- typedef struct packed {
- logic valid;
- logic [XLEN-1:0] lower_bound;
- logic [XLEN-1:0] upper_bound;
- } pmp_region_t;
-
- function automatic logic [XLEN-1:0] pmpaddr_to_paddr(input pmpaddr_entry_t pmpaddr);
- logic [XLEN-1:0] paddr;
- paddr = pmpaddr << 2;
- if (PHYS_ADDR_WIDTH < XLEN) begin
- paddr[XLEN-1:PHYS_ADDR_WIDTH] = '0;
- end
- return paddr;
- endfunction
-
- function automatic int unsigned napot_trailing_ones(input pmpaddr_entry_t pmpaddr);
- int unsigned ones;
- ones = 0;
- for (int bit_idx = 0; bit_idx < (PHYS_ADDR_WIDTH - 2); bit_idx++) begin
- if (pmpaddr[bit_idx]) begin
- ones++;
- end else begin
- break;
- end
- end
- return ones;
- endfunction
-
- function automatic pmp_region_t pmp_region(input int unsigned entry_idx);
- pmp_region_t region;
- logic [1:0] address_matching;
- int unsigned ones;
- logic [XLEN-1:0] napot_mask;
- logic [XLEN-1:0] napot_base;
-
- region.valid = 1'b0;
- region.lower_bound = '0;
- region.upper_bound = '0;
- address_matching = pmpcfg_entries[entry_idx][PMPCFG_A_HI:PMPCFG_A_LO];
-
- unique case (address_matching)
- PMP_MODE_OFF: begin
- region.valid = 1'b0;
- end
- PMP_MODE_TOR: begin
- region.valid = 1'b1;
- region.lower_bound = (entry_idx == 0) ? '0 : pmpaddr_to_paddr(pmpaddr_entries[entry_idx - 1]);
- region.upper_bound = pmpaddr_to_paddr(pmpaddr_entries[entry_idx]);
- if (region.upper_bound <= region.lower_bound) begin
- region.valid = 1'b0;
- end
- end
- PMP_MODE_NA4: begin
- region.valid = 1'b1;
- region.lower_bound = pmpaddr_to_paddr(pmpaddr_entries[entry_idx]);
- region.upper_bound = region.lower_bound + 64'd4;
- end
- PMP_MODE_NAPOT: begin
- region.valid = 1'b1;
- ones = napot_trailing_ones(pmpaddr_entries[entry_idx]);
- napot_mask = (64'd1 << (ones + 1)) - 64'd1;
- napot_base = (pmpaddr_entries[entry_idx] & ~napot_mask) << 2;
- if (PHYS_ADDR_WIDTH < XLEN) begin
- napot_base[XLEN-1:PHYS_ADDR_WIDTH] = '0;
- end
- region.lower_bound = napot_base;
- region.upper_bound = napot_base + (64'd1 << (ones + 3));
- end
- default: begin
- region.valid = 1'b0;
- end
- endcase
-
- return region;
- endfunction
-
- function automatic logic ranges_overlap(
- input logic [XLEN-1:0] access_lower,
- input logic [XLEN-1:0] access_upper,
- input logic [XLEN-1:0] region_lower,
- input logic [XLEN-1:0] region_upper
- );
- return (access_lower < region_upper) && (access_upper > region_lower);
- endfunction
-
- function automatic logic range_contains(
- input logic [XLEN-1:0] access_lower,
- input logic [XLEN-1:0] access_upper,
- input logic [XLEN-1:0] region_lower,
- input logic [XLEN-1:0] region_upper
- );
- return (access_lower >= region_lower) && (access_upper <= region_upper);
- endfunction
-
- function automatic logic permissions_allow(
- input pmpcfg_entry_t cfg,
- input logic is_fetch,
- input logic is_store
- );
- if (is_fetch) begin
- return cfg[PMPCFG_X_BIT];
- end
- if (is_store) begin
- return cfg[PMPCFG_W_BIT];
- end
- return cfg[PMPCFG_R_BIT];
- endfunction
-
- always_comb begin
- logic [XLEN-1:0] access_lower;
- logic [XLEN-1:0] access_upper;
- logic [3:0] normalized_size;
- logic matched;
- pmp_region_t region;
-
- normalized_size = (req_size == 4'd0) ? 4'd1 : req_size;
- access_lower = req_paddr;
- access_upper = req_paddr + {{(XLEN-4){1'b0}}, normalized_size};
- matched = 1'b0;
- region = '0;
- access_fault = 1'b0;
-
- if (req_valid) begin
- for (int unsigned entry_idx = 0; entry_idx < PMP_ENTRY_COUNT; entry_idx++) begin
- region = pmp_region(entry_idx);
- if (!matched && region.valid &&
- ranges_overlap(access_lower, access_upper, region.lower_bound, region.upper_bound)) begin
- matched = 1'b1;
- if (!range_contains(access_lower, access_upper, region.lower_bound, region.upper_bound)) begin
- access_fault = 1'b1;
- end else if ((priv_mode != PRIV_MODE_M) || pmpcfg_entries[entry_idx][PMPCFG_L_BIT]) begin
- access_fault = !permissions_allow(pmpcfg_entries[entry_idx], req_is_fetch, req_is_store);
- end
- end
- end
-
- if (!matched && (priv_mode != PRIV_MODE_M)) begin
- access_fault = 1'b1;
- end
- end
- end
-
-endmodule
generated by cgit v1.2.3 (git 2.46.0) at 2026-11-10 14:53:05 +0000