target/riscv: add support for svnapot extension

- add PTE_N bit
- add PTE_N bit check for inner PTE
- update address translation to support 64KiB continuous region (napot_bits = 4)

Signed-off-by: Weiwei Li <liweiwei@iscas.ac.cn>
Signed-off-by: Junqiang Wang <wangjunqiang@iscas.ac.cn>
Reviewed-by: Anup Patel <anup@brainfault.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20220204022658.18097-4-liweiwei@iscas.ac.cn>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
This commit is contained in:
Weiwei Li 2022-02-04 10:26:56 +08:00 committed by Alistair Francis
parent b6ecc63c56
commit 2bacb22446
3 changed files with 18 additions and 3 deletions

View File

@ -774,6 +774,8 @@ static Property riscv_cpu_properties[] = {
DEFINE_PROP_UINT16("vlen", RISCVCPU, cfg.vlen, 128),
DEFINE_PROP_UINT16("elen", RISCVCPU, cfg.elen, 64),
DEFINE_PROP_BOOL("svnapot", RISCVCPU, cfg.ext_svnapot, false),
DEFINE_PROP_BOOL("zba", RISCVCPU, cfg.ext_zba, true),
DEFINE_PROP_BOOL("zbb", RISCVCPU, cfg.ext_zbb, true),
DEFINE_PROP_BOOL("zbc", RISCVCPU, cfg.ext_zbc, true),

View File

@ -561,6 +561,7 @@ typedef enum {
#define PTE_A 0x040 /* Accessed */
#define PTE_D 0x080 /* Dirty */
#define PTE_SOFT 0x300 /* Reserved for Software */
#define PTE_N 0x8000000000000000ULL /* NAPOT translation */
/* Page table PPN shift amount */
#define PTE_PPN_SHIFT 10

View File

@ -753,6 +753,8 @@ static int get_physical_address(CPURISCVState *env, hwaddr *physical,
bool use_background = false;
hwaddr ppn;
RISCVCPU *cpu = env_archcpu(env);
int napot_bits = 0;
target_ulong napot_mask;
/*
* Check if we should use the background registers for the two
@ -937,7 +939,7 @@ restart:
return TRANSLATE_FAIL;
} else if (!(pte & (PTE_R | PTE_W | PTE_X))) {
/* Inner PTE, continue walking */
if (pte & (PTE_D | PTE_A | PTE_U)) {
if (pte & (PTE_D | PTE_A | PTE_U | PTE_N)) {
return TRANSLATE_FAIL;
}
base = ppn << PGSHIFT;
@ -1013,8 +1015,18 @@ restart:
/* for superpage mappings, make a fake leaf PTE for the TLB's
benefit. */
target_ulong vpn = addr >> PGSHIFT;
*physical = ((ppn | (vpn & ((1L << ptshift) - 1))) << PGSHIFT) |
(addr & ~TARGET_PAGE_MASK);
if (cpu->cfg.ext_svnapot && (pte & PTE_N)) {
napot_bits = ctzl(ppn) + 1;
if ((i != (levels - 1)) || (napot_bits != 4)) {
return TRANSLATE_FAIL;
}
}
napot_mask = (1 << napot_bits) - 1;
*physical = (((ppn & ~napot_mask) | (vpn & napot_mask) |
(vpn & (((target_ulong)1 << ptshift) - 1))
) << PGSHIFT) | (addr & ~TARGET_PAGE_MASK);
/* set permissions on the TLB entry */
if ((pte & PTE_R) || ((pte & PTE_X) && mxr)) {