riscv: add physical memory protection (PMP) support
These codes are written by me based on the privileged instruction set. I tested it by qemu/riscv-probe. Change-Id: I2e9e0c94e6518f63ade7680a3ce68bacfae219d4 Signed-off-by: Xiang Wang <wxjstz@126.com> Reviewed-on: https://review.coreboot.org/28569 Reviewed-by: Philipp Hug <philipp@hug.cx> Reviewed-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net> Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
This commit is contained in:
Xiang Wang
Patrick Georgi
parent
a08475e9ab
commit
4356e09235
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@ -54,6 +54,7 @@ bootblock-y += mcall.c
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bootblock-y += virtual_memory.c
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bootblock-y += boot.c
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bootblock-y += misc.c
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bootblock-y += pmp.c
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bootblock-y += \
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$(top)/src/lib/memchr.c \
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$(top)/src/lib/memcmp.c \
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@ -82,6 +83,7 @@ ifeq ($(CONFIG_ARCH_ROMSTAGE_RISCV),y)
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romstage-y += boot.c
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romstage-y += stages.c
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romstage-y += misc.c
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romstage-y += pmp.c
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romstage-y += \
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$(top)/src/lib/memchr.c \
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$(top)/src/lib/memcmp.c \
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@ -120,6 +122,7 @@ ramstage-y += misc.c
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ramstage-y += boot.c
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ramstage-y += tables.c
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ramstage-y += payload.S
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ramstage-y += pmp.c
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ramstage-y += \
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$(top)/src/lib/memchr.c \
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$(top)/src/lib/memcmp.c \
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@ -0,0 +1,31 @@
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/*
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* This file is part of the coreboot project.
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*
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* Copyright (C) 2018 HardenedLinux
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; version 2 of the License.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*/
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#ifndef __RISCV_PMP_H__
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#define __RISCV_PMP_H__
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/*
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* this function needs to be implemented by a specific SoC.
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* return number of PMP entries for current hart
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*/
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extern int pmp_entries_num(void);
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/* reset PMP setting */
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void reset_pmp(void);
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/* set up PMP record */
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void setup_pmp(uintptr_t base, uintptr_t size, uintptr_t flags);
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#endif /* __RISCV_PMP_H__ */
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@ -0,0 +1,321 @@
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/*
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* This file is part of the coreboot project.
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*
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* Copyright (C) 2018 HardenedLinux
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; version 2 of the License.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*/
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#include <arch/encoding.h>
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#include <stdint.h>
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#include <arch/pmp.h>
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#include <console/console.h>
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#include <commonlib/helpers.h>
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#define GRANULE (1 << PMP_SHIFT)
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/*
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* This structure is used to temporarily record PMP
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* configuration information.
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*/
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typedef struct {
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/* used to record the value of pmpcfg[i] */
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uintptr_t cfg;
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/*
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* When generating a TOR type configuration,
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* the previous entry needs to record the starting address.
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* used to record the value of pmpaddr[i - 1]
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*/
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uintptr_t previous_address;
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/* used to record the value of pmpaddr[i] */
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uintptr_t address;
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} pmpcfg_t;
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/* This variable is used to record which entries have been used. */
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static uintptr_t pmp_entry_used_mask;
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/* helper function used to read pmpcfg[idx] */
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static uintptr_t read_pmpcfg(int idx)
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{
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#if __riscv_xlen == 32
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int shift = 8 * (idx & 3);
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switch (idx >> 2) {
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case 0:
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return (read_csr(pmpcfg0) >> shift) & 0xff;
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case 1:
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return (read_csr(pmpcfg1) >> shift) & 0xff;
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case 2:
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return (read_csr(pmpcfg2) >> shift) & 0xff;
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case 3:
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return (read_csr(pmpcfg3) >> shift) & 0xff;
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}
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#elif __riscv_xlen == 64
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int shift = 8 * (idx & 7);
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switch (idx >> 3) {
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case 0:
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return (read_csr(pmpcfg0) >> shift) & 0xff;
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case 1:
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return (read_csr(pmpcfg2) >> shift) & 0xff;
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}
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#endif
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return -1;
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}
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/* helper function used to write pmpcfg[idx] */
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static void write_pmpcfg(int idx, uintptr_t cfg)
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{
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uintptr_t old;
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uintptr_t new;
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#if __riscv_xlen == 32
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int shift = 8 * (idx & 3);
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switch (idx >> 2) {
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case 0:
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old = read_csr(pmpcfg0);
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new = (old & ~((uintptr_t)0xff << shift))
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| ((cfg & 0xff) << shift);
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write_csr(pmpcfg0, new);
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break;
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case 1:
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old = read_csr(pmpcfg1);
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new = (old & ~((uintptr_t)0xff << shift))
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| ((cfg & 0xff) << shift);
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write_csr(pmpcfg1, new);
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break;
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case 2:
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old = read_csr(pmpcfg2);
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new = (old & ~((uintptr_t)0xff << shift))
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| ((cfg & 0xff) << shift);
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write_csr(pmpcfg2, new);
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break;
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case 3:
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old = read_csr(pmpcfg3);
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new = (old & ~((uintptr_t)0xff << shift))
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| ((cfg & 0xff) << shift);
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write_csr(pmpcfg3, new);
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break;
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}
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#elif __riscv_xlen == 64
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int shift = 8 * (idx & 7);
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switch (idx >> 3) {
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case 0:
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old = read_csr(pmpcfg0);
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new = (old & ~((uintptr_t)0xff << shift))
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| ((cfg & 0xff) << shift);
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write_csr(pmpcfg0, new);
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break;
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case 1:
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old = read_csr(pmpcfg2);
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new = (old & ~((uintptr_t)0xff << shift))
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| ((cfg & 0xff) << shift);
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write_csr(pmpcfg2, new);
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break;
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}
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#endif
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if (read_pmpcfg(idx) != cfg)
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die("write pmpcfg failure!");
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}
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/* helper function used to read pmpaddr[idx] */
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static uintptr_t read_pmpaddr(int idx)
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{
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switch (idx) {
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case 0:
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return read_csr(pmpaddr0);
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case 1:
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return read_csr(pmpaddr1);
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case 2:
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return read_csr(pmpaddr2);
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case 3:
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return read_csr(pmpaddr3);
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case 4:
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return read_csr(pmpaddr4);
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case 5:
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return read_csr(pmpaddr5);
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case 6:
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return read_csr(pmpaddr6);
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case 7:
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return read_csr(pmpaddr7);
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case 8:
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return read_csr(pmpaddr8);
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case 9:
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return read_csr(pmpaddr9);
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case 10:
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return read_csr(pmpaddr10);
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case 11:
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return read_csr(pmpaddr11);
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case 12:
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return read_csr(pmpaddr12);
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case 13:
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return read_csr(pmpaddr13);
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case 14:
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return read_csr(pmpaddr14);
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case 15:
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return read_csr(pmpaddr15);
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}
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return -1;
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}
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/* helper function used to write pmpaddr[idx] */
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static void write_pmpaddr(int idx, uintptr_t val)
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{
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switch (idx) {
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case 0:
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write_csr(pmpaddr0, val);
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break;
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case 1:
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write_csr(pmpaddr1, val);
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break;
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case 2:
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write_csr(pmpaddr2, val);
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break;
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case 3:
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write_csr(pmpaddr3, val);
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break;
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case 4:
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write_csr(pmpaddr4, val);
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break;
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case 5:
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write_csr(pmpaddr5, val);
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break;
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case 6:
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write_csr(pmpaddr6, val);
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break;
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case 7:
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write_csr(pmpaddr7, val);
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break;
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case 8:
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write_csr(pmpaddr8, val);
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break;
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case 9:
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write_csr(pmpaddr9, val);
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break;
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case 10:
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write_csr(pmpaddr10, val);
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break;
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case 11:
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write_csr(pmpaddr11, val);
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break;
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case 12:
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write_csr(pmpaddr12, val);
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break;
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case 13:
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write_csr(pmpaddr13, val);
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break;
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case 14:
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write_csr(pmpaddr14, val);
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break;
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case 15:
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write_csr(pmpaddr15, val);
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break;
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}
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if (read_pmpaddr(idx) != val)
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die("write pmpaddr failure");
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}
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/* Generate a PMP configuration of type NA4/NAPOT */
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static pmpcfg_t generate_pmp_napot(
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uintptr_t base, uintptr_t size, uintptr_t flags)
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{
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pmpcfg_t p;
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flags = flags & (PMP_R | PMP_W | PMP_X | PMP_L);
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p.cfg = flags | (size > GRANULE ? PMP_NAPOT : PMP_NA4);
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p.previous_address = 0;
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p.address = (base + (size / 2 - 1)) >> PMP_SHIFT;
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return p;
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}
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/* Generate a PMP configuration of type TOR */
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static pmpcfg_t generate_pmp_range(
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uintptr_t base, uintptr_t size, uintptr_t flags)
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{
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pmpcfg_t p;
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flags = flags & (PMP_R | PMP_W | PMP_X | PMP_L);
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p.cfg = flags | PMP_TOR;
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p.previous_address = base >> PMP_SHIFT;
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p.address = (base + size) >> PMP_SHIFT;
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return p;
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}
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/* Generate a PMP configuration */
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static pmpcfg_t generate_pmp(uintptr_t base, uintptr_t size, uintptr_t flags)
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{
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if (IS_POWER_OF_2(size) && (size >= 4) && ((base & (size - 1)) == 0))
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return generate_pmp_napot(base, size, flags);
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else
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return generate_pmp_range(base, size, flags);
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}
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/*
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* find empty PMP entry by type
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* TOR type configuration requires two consecutive PMP entries,
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* others requires one.
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*/
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static int find_empty_pmp_entry(int is_range)
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{
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int free_entries = 0;
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for (int i = 0; i < pmp_entries_num(); i++) {
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if (pmp_entry_used_mask & (1 << i))
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free_entries = 0;
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else
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free_entries++;
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if (is_range && (free_entries == 2))
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return i;
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if (!is_range && (free_entries == 1))
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return i;
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}
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die("Too many PMP configurations, no free entries can be used!");
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return -1;
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}
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/*
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* mark PMP entry has be used
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* this function need be used with find_entry_pmp_entry
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*
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* n = find_empty_pmp_entry(is_range)
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* ... // PMP set operate
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* mask_pmp_entry_used(n);
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*/
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static void mask_pmp_entry_used(int idx)
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{
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pmp_entry_used_mask |= 1 << idx;
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}
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/* reset PMP setting */
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void reset_pmp(void)
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{
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for (int i = 0; i < pmp_entries_num(); i++) {
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if (read_pmpcfg(i) & PMP_L)
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die("Some PMP configurations are locked "
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"and cannot be reset!");
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write_pmpcfg(i, 0);
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write_pmpaddr(i, 0);
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}
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}
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/* set up PMP record */
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void setup_pmp(uintptr_t base, uintptr_t size, uintptr_t flags)
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{
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pmpcfg_t p;
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int is_range, n;
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p = generate_pmp(base, size, flags);
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is_range = ((p.cfg & PMP_A) == PMP_TOR);
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n = find_empty_pmp_entry(is_range);
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write_pmpaddr(n, p.address);
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if (is_range)
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write_pmpaddr(n - 1, p.previous_address);
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write_pmpcfg(n, p.cfg);
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mask_pmp_entry_used(n);
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if (is_range)
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mask_pmp_entry_used(n - 1);
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}
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