opensbi/lib/sbi/sbi_hart.c
Atish Patra 6bb6b61c27 lib: sbi: Add support for smcsrind and smcdeleg
Smcsrind allows generic indirect CSR access mechanism while
Smcdeleg allows delegating hpmcounters in Supervisor mode.

Enable both extensions and set the appropriate bits in mstateen
and menvcfg.

Co-developed-by: Kaiwen Xue <kaiwenxue1@gmail.com>
Signed-off-by: Atish Patra <atishp@rivosinc.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
2024-03-04 10:20:41 +05:30

1060 lines
29 KiB
C

/*
* SPDX-License-Identifier: BSD-2-Clause
*
* Copyright (c) 2019 Western Digital Corporation or its affiliates.
*
* Authors:
* Anup Patel <anup.patel@wdc.com>
*/
#include <sbi/riscv_asm.h>
#include <sbi/riscv_barrier.h>
#include <sbi/riscv_encoding.h>
#include <sbi/riscv_fp.h>
#include <sbi/sbi_bitops.h>
#include <sbi/sbi_console.h>
#include <sbi/sbi_domain.h>
#include <sbi/sbi_csr_detect.h>
#include <sbi/sbi_error.h>
#include <sbi/sbi_hart.h>
#include <sbi/sbi_math.h>
#include <sbi/sbi_platform.h>
#include <sbi/sbi_pmu.h>
#include <sbi/sbi_string.h>
#include <sbi/sbi_trap.h>
#include <sbi/sbi_hfence.h>
extern void __sbi_expected_trap(void);
extern void __sbi_expected_trap_hext(void);
void (*sbi_hart_expected_trap)(void) = &__sbi_expected_trap;
static unsigned long hart_features_offset;
static void mstatus_init(struct sbi_scratch *scratch)
{
int cidx;
unsigned long mstatus_val = 0;
unsigned int mhpm_mask = sbi_hart_mhpm_mask(scratch);
uint64_t mhpmevent_init_val = 0;
uint64_t menvcfg_val, mstateen_val;
/* Enable FPU */
if (misa_extension('D') || misa_extension('F'))
mstatus_val |= MSTATUS_FS;
/* Enable Vector context */
if (misa_extension('V'))
mstatus_val |= MSTATUS_VS;
csr_write(CSR_MSTATUS, mstatus_val);
/* Disable user mode usage of all perf counters except default ones (CY, TM, IR) */
if (misa_extension('S') &&
sbi_hart_priv_version(scratch) >= SBI_HART_PRIV_VER_1_10)
csr_write(CSR_SCOUNTEREN, 7);
/**
* OpenSBI doesn't use any PMU counters in M-mode.
* Supervisor mode usage for all counters are enabled by default
* But counters will not run until mcountinhibit is set.
*/
if (sbi_hart_priv_version(scratch) >= SBI_HART_PRIV_VER_1_10)
csr_write(CSR_MCOUNTEREN, -1);
/* All programmable counters will start running at runtime after S-mode request */
if (sbi_hart_priv_version(scratch) >= SBI_HART_PRIV_VER_1_11)
csr_write(CSR_MCOUNTINHIBIT, 0xFFFFFFF8);
/**
* The mhpmeventn[h] CSR should be initialized with interrupt disabled
* and inhibited running in M-mode during init.
*/
mhpmevent_init_val |= (MHPMEVENT_OF | MHPMEVENT_MINH);
for (cidx = 0; cidx <= 28; cidx++) {
if (!(mhpm_mask & 1 << (cidx + 3)))
continue;
#if __riscv_xlen == 32
csr_write_num(CSR_MHPMEVENT3 + cidx,
mhpmevent_init_val & 0xFFFFFFFF);
if (sbi_hart_has_extension(scratch, SBI_HART_EXT_SSCOFPMF))
csr_write_num(CSR_MHPMEVENT3H + cidx,
mhpmevent_init_val >> BITS_PER_LONG);
#else
csr_write_num(CSR_MHPMEVENT3 + cidx, mhpmevent_init_val);
#endif
}
if (sbi_hart_has_extension(scratch, SBI_HART_EXT_SMSTATEEN)) {
mstateen_val = csr_read(CSR_MSTATEEN0);
#if __riscv_xlen == 32
mstateen_val |= ((uint64_t)csr_read(CSR_MSTATEEN0H)) << 32;
#endif
mstateen_val |= SMSTATEEN_STATEN;
mstateen_val |= SMSTATEEN0_CONTEXT;
mstateen_val |= SMSTATEEN0_HSENVCFG;
if (sbi_hart_has_extension(scratch, SBI_HART_EXT_SMAIA))
mstateen_val |= (SMSTATEEN0_AIA | SMSTATEEN0_IMSIC);
else
mstateen_val &= ~(SMSTATEEN0_AIA | SMSTATEEN0_IMSIC);
if (sbi_hart_has_extension(scratch, SBI_HART_EXT_SMAIA) ||
sbi_hart_has_extension(scratch, SBI_HART_EXT_SMCSRIND))
mstateen_val |= (SMSTATEEN0_SVSLCT);
else
mstateen_val &= ~(SMSTATEEN0_SVSLCT);
csr_write(CSR_MSTATEEN0, mstateen_val);
#if __riscv_xlen == 32
csr_write(CSR_MSTATEEN0H, mstateen_val >> 32);
#endif
}
if (sbi_hart_priv_version(scratch) >= SBI_HART_PRIV_VER_1_12) {
menvcfg_val = csr_read(CSR_MENVCFG);
#if __riscv_xlen == 32
menvcfg_val |= ((uint64_t)csr_read(CSR_MENVCFGH)) << 32;
#endif
#define __set_menvcfg_ext(__ext, __bits) \
if (sbi_hart_has_extension(scratch, __ext)) \
menvcfg_val |= __bits;
/*
* Enable access to extensions if they are present in the
* hardware or in the device tree.
*/
__set_menvcfg_ext(SBI_HART_EXT_ZICBOZ, ENVCFG_CBZE)
__set_menvcfg_ext(SBI_HART_EXT_ZICBOM, ENVCFG_CBCFE)
__set_menvcfg_ext(SBI_HART_EXT_ZICBOM,
ENVCFG_CBIE_INV << ENVCFG_CBIE_SHIFT)
#if __riscv_xlen > 32
__set_menvcfg_ext(SBI_HART_EXT_SVPBMT, ENVCFG_PBMTE)
#endif
__set_menvcfg_ext(SBI_HART_EXT_SSTC, ENVCFG_STCE)
__set_menvcfg_ext(SBI_HART_EXT_SMCDELEG, ENVCFG_CDE);
#undef __set_menvcfg_ext
csr_write(CSR_MENVCFG, menvcfg_val);
#if __riscv_xlen == 32
csr_write(CSR_MENVCFGH, menvcfg_val >> 32);
#endif
/* Enable S-mode access to seed CSR */
if (sbi_hart_has_extension(scratch, SBI_HART_EXT_ZKR)) {
csr_set(CSR_MSECCFG, MSECCFG_SSEED);
csr_clear(CSR_MSECCFG, MSECCFG_USEED);
}
}
/* Disable all interrupts */
csr_write(CSR_MIE, 0);
/* Disable S-mode paging */
if (misa_extension('S'))
csr_write(CSR_SATP, 0);
}
static int fp_init(struct sbi_scratch *scratch)
{
#ifdef __riscv_flen
int i;
#endif
if (!misa_extension('D') && !misa_extension('F'))
return 0;
if (!(csr_read(CSR_MSTATUS) & MSTATUS_FS))
return SBI_EINVAL;
#ifdef __riscv_flen
for (i = 0; i < 32; i++)
init_fp_reg(i);
csr_write(CSR_FCSR, 0);
#endif
return 0;
}
static int delegate_traps(struct sbi_scratch *scratch)
{
const struct sbi_platform *plat = sbi_platform_ptr(scratch);
unsigned long interrupts, exceptions;
if (!misa_extension('S'))
/* No delegation possible as mideleg does not exist */
return 0;
/* Send M-mode interrupts and most exceptions to S-mode */
interrupts = MIP_SSIP | MIP_STIP | MIP_SEIP;
interrupts |= sbi_pmu_irq_bit();
exceptions = (1U << CAUSE_MISALIGNED_FETCH) | (1U << CAUSE_BREAKPOINT) |
(1U << CAUSE_USER_ECALL);
if (sbi_platform_has_mfaults_delegation(plat))
exceptions |= (1U << CAUSE_FETCH_PAGE_FAULT) |
(1U << CAUSE_LOAD_PAGE_FAULT) |
(1U << CAUSE_STORE_PAGE_FAULT);
/*
* If hypervisor extension available then we only handle hypervisor
* calls (i.e. ecalls from HS-mode) in M-mode.
*
* The HS-mode will additionally handle supervisor calls (i.e. ecalls
* from VS-mode), Guest page faults and Virtual interrupts.
*/
if (misa_extension('H')) {
exceptions |= (1U << CAUSE_VIRTUAL_SUPERVISOR_ECALL);
exceptions |= (1U << CAUSE_FETCH_GUEST_PAGE_FAULT);
exceptions |= (1U << CAUSE_LOAD_GUEST_PAGE_FAULT);
exceptions |= (1U << CAUSE_VIRTUAL_INST_FAULT);
exceptions |= (1U << CAUSE_STORE_GUEST_PAGE_FAULT);
}
csr_write(CSR_MIDELEG, interrupts);
csr_write(CSR_MEDELEG, exceptions);
return 0;
}
void sbi_hart_delegation_dump(struct sbi_scratch *scratch,
const char *prefix, const char *suffix)
{
if (!misa_extension('S'))
/* No delegation possible as mideleg does not exist*/
return;
sbi_printf("%sMIDELEG%s: 0x%" PRILX "\n",
prefix, suffix, csr_read(CSR_MIDELEG));
sbi_printf("%sMEDELEG%s: 0x%" PRILX "\n",
prefix, suffix, csr_read(CSR_MEDELEG));
}
unsigned int sbi_hart_mhpm_mask(struct sbi_scratch *scratch)
{
struct sbi_hart_features *hfeatures =
sbi_scratch_offset_ptr(scratch, hart_features_offset);
return hfeatures->mhpm_mask;
}
unsigned int sbi_hart_pmp_count(struct sbi_scratch *scratch)
{
struct sbi_hart_features *hfeatures =
sbi_scratch_offset_ptr(scratch, hart_features_offset);
return hfeatures->pmp_count;
}
unsigned int sbi_hart_pmp_log2gran(struct sbi_scratch *scratch)
{
struct sbi_hart_features *hfeatures =
sbi_scratch_offset_ptr(scratch, hart_features_offset);
return hfeatures->pmp_log2gran;
}
unsigned int sbi_hart_pmp_addrbits(struct sbi_scratch *scratch)
{
struct sbi_hart_features *hfeatures =
sbi_scratch_offset_ptr(scratch, hart_features_offset);
return hfeatures->pmp_addr_bits;
}
unsigned int sbi_hart_mhpm_bits(struct sbi_scratch *scratch)
{
struct sbi_hart_features *hfeatures =
sbi_scratch_offset_ptr(scratch, hart_features_offset);
return hfeatures->mhpm_bits;
}
/*
* Returns Smepmp flags for a given domain and region based on permissions.
*/
static unsigned int sbi_hart_get_smepmp_flags(struct sbi_scratch *scratch,
struct sbi_domain *dom,
struct sbi_domain_memregion *reg)
{
unsigned int pmp_flags = 0;
if (SBI_DOMAIN_MEMREGION_IS_SHARED(reg->flags)) {
/* Read only for both M and SU modes */
if (SBI_DOMAIN_MEMREGION_IS_SUR_MR(reg->flags))
pmp_flags = (PMP_L | PMP_R | PMP_W | PMP_X);
/* Execute for SU but Read/Execute for M mode */
else if (SBI_DOMAIN_MEMREGION_IS_SUX_MRX(reg->flags))
/* locked region */
pmp_flags = (PMP_L | PMP_W | PMP_X);
/* Execute only for both M and SU modes */
else if (SBI_DOMAIN_MEMREGION_IS_SUX_MX(reg->flags))
pmp_flags = (PMP_L | PMP_W);
/* Read/Write for both M and SU modes */
else if (SBI_DOMAIN_MEMREGION_IS_SURW_MRW(reg->flags))
pmp_flags = (PMP_W | PMP_X);
/* Read only for SU mode but Read/Write for M mode */
else if (SBI_DOMAIN_MEMREGION_IS_SUR_MRW(reg->flags))
pmp_flags = (PMP_W);
} else if (SBI_DOMAIN_MEMREGION_M_ONLY_ACCESS(reg->flags)) {
/*
* When smepmp is supported and used, M region cannot have RWX
* permissions on any region.
*/
if ((reg->flags & SBI_DOMAIN_MEMREGION_M_ACCESS_MASK)
== SBI_DOMAIN_MEMREGION_M_RWX) {
sbi_printf("%s: M-mode only regions cannot have"
"RWX permissions\n", __func__);
return 0;
}
/* M-mode only access regions are always locked */
pmp_flags |= PMP_L;
if (reg->flags & SBI_DOMAIN_MEMREGION_M_READABLE)
pmp_flags |= PMP_R;
if (reg->flags & SBI_DOMAIN_MEMREGION_M_WRITABLE)
pmp_flags |= PMP_W;
if (reg->flags & SBI_DOMAIN_MEMREGION_M_EXECUTABLE)
pmp_flags |= PMP_X;
} else if (SBI_DOMAIN_MEMREGION_SU_ONLY_ACCESS(reg->flags)) {
if (reg->flags & SBI_DOMAIN_MEMREGION_SU_READABLE)
pmp_flags |= PMP_R;
if (reg->flags & SBI_DOMAIN_MEMREGION_SU_WRITABLE)
pmp_flags |= PMP_W;
if (reg->flags & SBI_DOMAIN_MEMREGION_SU_EXECUTABLE)
pmp_flags |= PMP_X;
}
return pmp_flags;
}
static void sbi_hart_smepmp_set(struct sbi_scratch *scratch,
struct sbi_domain *dom,
struct sbi_domain_memregion *reg,
unsigned int pmp_idx,
unsigned int pmp_flags,
unsigned int pmp_log2gran,
unsigned long pmp_addr_max)
{
unsigned long pmp_addr = reg->base >> PMP_SHIFT;
if (pmp_log2gran <= reg->order && pmp_addr < pmp_addr_max) {
pmp_set(pmp_idx, pmp_flags, reg->base, reg->order);
} else {
sbi_printf("Can not configure pmp for domain %s because"
" memory region address 0x%lx or size 0x%lx "
"is not in range.\n", dom->name, reg->base,
reg->order);
}
}
static int sbi_hart_smepmp_configure(struct sbi_scratch *scratch,
unsigned int pmp_count,
unsigned int pmp_log2gran,
unsigned long pmp_addr_max)
{
struct sbi_domain_memregion *reg;
struct sbi_domain *dom = sbi_domain_thishart_ptr();
unsigned int pmp_idx, pmp_flags;
/*
* Set the RLB so that, we can write to PMP entries without
* enforcement even if some entries are locked.
*/
csr_set(CSR_MSECCFG, MSECCFG_RLB);
/* Disable the reserved entry */
pmp_disable(SBI_SMEPMP_RESV_ENTRY);
/* Program M-only regions when MML is not set. */
pmp_idx = 0;
sbi_domain_for_each_memregion(dom, reg) {
/* Skip reserved entry */
if (pmp_idx == SBI_SMEPMP_RESV_ENTRY)
pmp_idx++;
if (pmp_count <= pmp_idx)
break;
/* Skip shared and SU-only regions */
if (!SBI_DOMAIN_MEMREGION_M_ONLY_ACCESS(reg->flags)) {
pmp_idx++;
continue;
}
pmp_flags = sbi_hart_get_smepmp_flags(scratch, dom, reg);
if (!pmp_flags)
return 0;
sbi_hart_smepmp_set(scratch, dom, reg, pmp_idx++, pmp_flags,
pmp_log2gran, pmp_addr_max);
}
/* Set the MML to enforce new encoding */
csr_set(CSR_MSECCFG, MSECCFG_MML);
/* Program shared and SU-only regions */
pmp_idx = 0;
sbi_domain_for_each_memregion(dom, reg) {
/* Skip reserved entry */
if (pmp_idx == SBI_SMEPMP_RESV_ENTRY)
pmp_idx++;
if (pmp_count <= pmp_idx)
break;
/* Skip M-only regions */
if (SBI_DOMAIN_MEMREGION_M_ONLY_ACCESS(reg->flags)) {
pmp_idx++;
continue;
}
pmp_flags = sbi_hart_get_smepmp_flags(scratch, dom, reg);
if (!pmp_flags)
return 0;
sbi_hart_smepmp_set(scratch, dom, reg, pmp_idx++, pmp_flags,
pmp_log2gran, pmp_addr_max);
}
/*
* All entries are programmed.
* Keep the RLB bit so that dynamic mappings can be done.
*/
return 0;
}
static int sbi_hart_oldpmp_configure(struct sbi_scratch *scratch,
unsigned int pmp_count,
unsigned int pmp_log2gran,
unsigned long pmp_addr_max)
{
struct sbi_domain_memregion *reg;
struct sbi_domain *dom = sbi_domain_thishart_ptr();
unsigned int pmp_idx = 0;
unsigned int pmp_flags;
unsigned long pmp_addr;
sbi_domain_for_each_memregion(dom, reg) {
if (pmp_count <= pmp_idx)
break;
pmp_flags = 0;
/*
* If permissions are to be enforced for all modes on
* this region, the lock bit should be set.
*/
if (reg->flags & SBI_DOMAIN_MEMREGION_ENF_PERMISSIONS)
pmp_flags |= PMP_L;
if (reg->flags & SBI_DOMAIN_MEMREGION_SU_READABLE)
pmp_flags |= PMP_R;
if (reg->flags & SBI_DOMAIN_MEMREGION_SU_WRITABLE)
pmp_flags |= PMP_W;
if (reg->flags & SBI_DOMAIN_MEMREGION_SU_EXECUTABLE)
pmp_flags |= PMP_X;
pmp_addr = reg->base >> PMP_SHIFT;
if (pmp_log2gran <= reg->order && pmp_addr < pmp_addr_max) {
pmp_set(pmp_idx++, pmp_flags, reg->base, reg->order);
} else {
sbi_printf("Can not configure pmp for domain %s because"
" memory region address 0x%lx or size 0x%lx "
"is not in range.\n", dom->name, reg->base,
reg->order);
}
}
return 0;
}
int sbi_hart_map_saddr(unsigned long addr, unsigned long size)
{
/* shared R/W access for M and S/U mode */
unsigned int pmp_flags = (PMP_W | PMP_X);
unsigned long order, base = 0;
struct sbi_scratch *scratch = sbi_scratch_thishart_ptr();
/* If Smepmp is not supported no special mapping is required */
if (!sbi_hart_has_extension(scratch, SBI_HART_EXT_SMEPMP))
return SBI_OK;
if (is_pmp_entry_mapped(SBI_SMEPMP_RESV_ENTRY))
return SBI_ENOSPC;
for (order = MAX(sbi_hart_pmp_log2gran(scratch), log2roundup(size));
order <= __riscv_xlen; order++) {
if (order < __riscv_xlen) {
base = addr & ~((1UL << order) - 1UL);
if ((base <= addr) &&
(addr < (base + (1UL << order))) &&
(base <= (addr + size - 1UL)) &&
((addr + size - 1UL) < (base + (1UL << order))))
break;
} else {
return SBI_EFAIL;
}
}
pmp_set(SBI_SMEPMP_RESV_ENTRY, pmp_flags, base, order);
return SBI_OK;
}
int sbi_hart_unmap_saddr(void)
{
struct sbi_scratch *scratch = sbi_scratch_thishart_ptr();
if (!sbi_hart_has_extension(scratch, SBI_HART_EXT_SMEPMP))
return SBI_OK;
return pmp_disable(SBI_SMEPMP_RESV_ENTRY);
}
int sbi_hart_pmp_configure(struct sbi_scratch *scratch)
{
int rc;
unsigned int pmp_bits, pmp_log2gran;
unsigned int pmp_count = sbi_hart_pmp_count(scratch);
unsigned long pmp_addr_max;
if (!pmp_count)
return 0;
pmp_log2gran = sbi_hart_pmp_log2gran(scratch);
pmp_bits = sbi_hart_pmp_addrbits(scratch) - 1;
pmp_addr_max = (1UL << pmp_bits) | ((1UL << pmp_bits) - 1);
if (sbi_hart_has_extension(scratch, SBI_HART_EXT_SMEPMP))
rc = sbi_hart_smepmp_configure(scratch, pmp_count,
pmp_log2gran, pmp_addr_max);
else
rc = sbi_hart_oldpmp_configure(scratch, pmp_count,
pmp_log2gran, pmp_addr_max);
/*
* As per section 3.7.2 of privileged specification v1.12,
* virtual address translations can be speculatively performed
* (even before actual access). These, along with PMP traslations,
* can be cached. This can pose a problem with CPU hotplug
* and non-retentive suspend scenario because PMP states are
* not preserved.
* It is advisable to flush the caching structures under such
* conditions.
*/
if (misa_extension('S')) {
__asm__ __volatile__("sfence.vma");
/*
* If hypervisor mode is supported, flush caching
* structures in guest mode too.
*/
if (misa_extension('H'))
__sbi_hfence_gvma_all();
}
return rc;
}
int sbi_hart_priv_version(struct sbi_scratch *scratch)
{
struct sbi_hart_features *hfeatures =
sbi_scratch_offset_ptr(scratch, hart_features_offset);
return hfeatures->priv_version;
}
void sbi_hart_get_priv_version_str(struct sbi_scratch *scratch,
char *version_str, int nvstr)
{
char *temp;
struct sbi_hart_features *hfeatures =
sbi_scratch_offset_ptr(scratch, hart_features_offset);
switch (hfeatures->priv_version) {
case SBI_HART_PRIV_VER_1_10:
temp = "v1.10";
break;
case SBI_HART_PRIV_VER_1_11:
temp = "v1.11";
break;
case SBI_HART_PRIV_VER_1_12:
temp = "v1.12";
break;
default:
temp = "unknown";
break;
}
sbi_snprintf(version_str, nvstr, "%s", temp);
}
static inline void __sbi_hart_update_extension(
struct sbi_hart_features *hfeatures,
enum sbi_hart_extensions ext,
bool enable)
{
if (enable)
__set_bit(ext, hfeatures->extensions);
else
__clear_bit(ext, hfeatures->extensions);
}
/**
* Enable/Disable a particular hart extension
*
* @param scratch pointer to the HART scratch space
* @param ext the extension number to check
* @param enable new state of hart extension
*/
void sbi_hart_update_extension(struct sbi_scratch *scratch,
enum sbi_hart_extensions ext,
bool enable)
{
struct sbi_hart_features *hfeatures =
sbi_scratch_offset_ptr(scratch, hart_features_offset);
__sbi_hart_update_extension(hfeatures, ext, enable);
}
/**
* Check whether a particular hart extension is available
*
* @param scratch pointer to the HART scratch space
* @param ext the extension number to check
* @returns true (available) or false (not available)
*/
bool sbi_hart_has_extension(struct sbi_scratch *scratch,
enum sbi_hart_extensions ext)
{
struct sbi_hart_features *hfeatures =
sbi_scratch_offset_ptr(scratch, hart_features_offset);
if (__test_bit(ext, hfeatures->extensions))
return true;
else
return false;
}
#define __SBI_HART_EXT_DATA(_name, _id) { \
.name = #_name, \
.id = _id, \
}
const struct sbi_hart_ext_data sbi_hart_ext[] = {
__SBI_HART_EXT_DATA(smaia, SBI_HART_EXT_SMAIA),
__SBI_HART_EXT_DATA(smepmp, SBI_HART_EXT_SMEPMP),
__SBI_HART_EXT_DATA(smstateen, SBI_HART_EXT_SMSTATEEN),
__SBI_HART_EXT_DATA(sscofpmf, SBI_HART_EXT_SSCOFPMF),
__SBI_HART_EXT_DATA(sstc, SBI_HART_EXT_SSTC),
__SBI_HART_EXT_DATA(zicntr, SBI_HART_EXT_ZICNTR),
__SBI_HART_EXT_DATA(zihpm, SBI_HART_EXT_ZIHPM),
__SBI_HART_EXT_DATA(zkr, SBI_HART_EXT_ZKR),
__SBI_HART_EXT_DATA(smcntrpmf, SBI_HART_EXT_SMCNTRPMF),
__SBI_HART_EXT_DATA(xandespmu, SBI_HART_EXT_XANDESPMU),
__SBI_HART_EXT_DATA(zicboz, SBI_HART_EXT_ZICBOZ),
__SBI_HART_EXT_DATA(zicbom, SBI_HART_EXT_ZICBOM),
__SBI_HART_EXT_DATA(svpbmt, SBI_HART_EXT_SVPBMT),
__SBI_HART_EXT_DATA(sdtrig, SBI_HART_EXT_SDTRIG),
__SBI_HART_EXT_DATA(smcsrind, SBI_HART_EXT_SMCSRIND),
__SBI_HART_EXT_DATA(smcdeleg, SBI_HART_EXT_SMCDELEG),
};
/**
* Get the hart extensions in string format
*
* @param scratch pointer to the HART scratch space
* @param extensions_str pointer to a char array where the extensions string
* will be updated
* @param nestr length of the features_str. The feature string will be
* truncated if nestr is not long enough.
*/
void sbi_hart_get_extensions_str(struct sbi_scratch *scratch,
char *extensions_str, int nestr)
{
struct sbi_hart_features *hfeatures =
sbi_scratch_offset_ptr(scratch, hart_features_offset);
int offset = 0, ext = 0;
if (!extensions_str || nestr <= 0)
return;
sbi_memset(extensions_str, 0, nestr);
for_each_set_bit(ext, hfeatures->extensions, SBI_HART_EXT_MAX) {
sbi_snprintf(extensions_str + offset,
nestr - offset,
"%s,", sbi_hart_ext[ext].name);
offset = offset + sbi_strlen(sbi_hart_ext[ext].name) + 1;
}
if (offset)
extensions_str[offset - 1] = '\0';
else
sbi_strncpy(extensions_str, "none", nestr);
}
static unsigned long hart_pmp_get_allowed_addr(void)
{
unsigned long val = 0;
struct sbi_trap_info trap = {0};
csr_write_allowed(CSR_PMPCFG0, (ulong)&trap, 0);
if (trap.cause)
return 0;
csr_write_allowed(CSR_PMPADDR0, (ulong)&trap, PMP_ADDR_MASK);
if (!trap.cause) {
val = csr_read_allowed(CSR_PMPADDR0, (ulong)&trap);
if (trap.cause)
val = 0;
}
return val;
}
static int hart_mhpm_get_allowed_bits(void)
{
unsigned long val = ~(0UL);
struct sbi_trap_info trap = {0};
int num_bits = 0;
/**
* It is assumed that platforms will implement same number of bits for
* all the performance counters including mcycle/minstret.
*/
csr_write_allowed(CSR_MHPMCOUNTER3, (ulong)&trap, val);
if (!trap.cause) {
val = csr_read_allowed(CSR_MHPMCOUNTER3, (ulong)&trap);
if (trap.cause)
return 0;
}
num_bits = sbi_fls(val) + 1;
#if __riscv_xlen == 32
csr_write_allowed(CSR_MHPMCOUNTER3H, (ulong)&trap, val);
if (!trap.cause) {
val = csr_read_allowed(CSR_MHPMCOUNTER3H, (ulong)&trap);
if (trap.cause)
return num_bits;
}
num_bits += sbi_fls(val) + 1;
#endif
return num_bits;
}
static int hart_detect_features(struct sbi_scratch *scratch)
{
struct sbi_trap_info trap = {0};
struct sbi_hart_features *hfeatures =
sbi_scratch_offset_ptr(scratch, hart_features_offset);
unsigned long val, oldval;
bool has_zicntr = false;
int rc;
/* If hart features already detected then do nothing */
if (hfeatures->detected)
return 0;
/* Clear hart features */
sbi_memset(hfeatures->extensions, 0, sizeof(hfeatures->extensions));
hfeatures->pmp_count = 0;
hfeatures->mhpm_mask = 0;
hfeatures->priv_version = SBI_HART_PRIV_VER_UNKNOWN;
#define __check_hpm_csr(__csr, __mask) \
oldval = csr_read_allowed(__csr, (ulong)&trap); \
if (!trap.cause) { \
csr_write_allowed(__csr, (ulong)&trap, 1UL); \
if (!trap.cause && csr_swap(__csr, oldval) == 1UL) { \
(hfeatures->__mask) |= 1 << (__csr - CSR_MCYCLE); \
} \
}
#define __check_hpm_csr_2(__csr, __mask) \
__check_hpm_csr(__csr + 0, __mask) \
__check_hpm_csr(__csr + 1, __mask)
#define __check_hpm_csr_4(__csr, __mask) \
__check_hpm_csr_2(__csr + 0, __mask) \
__check_hpm_csr_2(__csr + 2, __mask)
#define __check_hpm_csr_8(__csr, __mask) \
__check_hpm_csr_4(__csr + 0, __mask) \
__check_hpm_csr_4(__csr + 4, __mask)
#define __check_hpm_csr_16(__csr, __mask) \
__check_hpm_csr_8(__csr + 0, __mask) \
__check_hpm_csr_8(__csr + 8, __mask)
#define __check_csr(__csr, __rdonly, __wrval, __field, __skip) \
oldval = csr_read_allowed(__csr, (ulong)&trap); \
if (!trap.cause) { \
if (__rdonly) { \
(hfeatures->__field)++; \
} else { \
csr_write_allowed(__csr, (ulong)&trap, __wrval);\
if (!trap.cause) { \
if (csr_swap(__csr, oldval) == __wrval) \
(hfeatures->__field)++; \
else \
goto __skip; \
} else { \
goto __skip; \
} \
} \
} else { \
goto __skip; \
}
#define __check_csr_2(__csr, __rdonly, __wrval, __field, __skip) \
__check_csr(__csr + 0, __rdonly, __wrval, __field, __skip) \
__check_csr(__csr + 1, __rdonly, __wrval, __field, __skip)
#define __check_csr_4(__csr, __rdonly, __wrval, __field, __skip) \
__check_csr_2(__csr + 0, __rdonly, __wrval, __field, __skip) \
__check_csr_2(__csr + 2, __rdonly, __wrval, __field, __skip)
#define __check_csr_8(__csr, __rdonly, __wrval, __field, __skip) \
__check_csr_4(__csr + 0, __rdonly, __wrval, __field, __skip) \
__check_csr_4(__csr + 4, __rdonly, __wrval, __field, __skip)
#define __check_csr_16(__csr, __rdonly, __wrval, __field, __skip) \
__check_csr_8(__csr + 0, __rdonly, __wrval, __field, __skip) \
__check_csr_8(__csr + 8, __rdonly, __wrval, __field, __skip)
#define __check_csr_32(__csr, __rdonly, __wrval, __field, __skip) \
__check_csr_16(__csr + 0, __rdonly, __wrval, __field, __skip) \
__check_csr_16(__csr + 16, __rdonly, __wrval, __field, __skip)
#define __check_csr_64(__csr, __rdonly, __wrval, __field, __skip) \
__check_csr_32(__csr + 0, __rdonly, __wrval, __field, __skip) \
__check_csr_32(__csr + 32, __rdonly, __wrval, __field, __skip)
/**
* Detect the allowed address bits & granularity. At least PMPADDR0
* should be implemented.
*/
val = hart_pmp_get_allowed_addr();
if (val) {
hfeatures->pmp_log2gran = sbi_ffs(val) + 2;
hfeatures->pmp_addr_bits = sbi_fls(val) + 1;
/* Detect number of PMP regions. At least PMPADDR0 should be implemented*/
__check_csr_64(CSR_PMPADDR0, 0, val, pmp_count, __pmp_skip);
}
__pmp_skip:
/* Detect number of MHPM counters */
__check_hpm_csr(CSR_MHPMCOUNTER3, mhpm_mask);
hfeatures->mhpm_bits = hart_mhpm_get_allowed_bits();
__check_hpm_csr_4(CSR_MHPMCOUNTER4, mhpm_mask);
__check_hpm_csr_8(CSR_MHPMCOUNTER8, mhpm_mask);
__check_hpm_csr_16(CSR_MHPMCOUNTER16, mhpm_mask);
/**
* No need to check for MHPMCOUNTERH for RV32 as they are expected to be
* implemented if MHPMCOUNTER is implemented.
*/
#undef __check_csr_64
#undef __check_csr_32
#undef __check_csr_16
#undef __check_csr_8
#undef __check_csr_4
#undef __check_csr_2
#undef __check_csr
#define __check_priv(__csr, __base_priv, __priv) \
val = csr_read_allowed(__csr, (ulong)&trap); \
if (!trap.cause && (hfeatures->priv_version >= __base_priv)) { \
hfeatures->priv_version = __priv; \
}
/* Detect if hart supports Priv v1.10 */
__check_priv(CSR_MCOUNTEREN,
SBI_HART_PRIV_VER_UNKNOWN, SBI_HART_PRIV_VER_1_10);
/* Detect if hart supports Priv v1.11 */
__check_priv(CSR_MCOUNTINHIBIT,
SBI_HART_PRIV_VER_1_10, SBI_HART_PRIV_VER_1_11);
/* Detect if hart supports Priv v1.12 */
__check_priv(CSR_MENVCFG,
SBI_HART_PRIV_VER_1_11, SBI_HART_PRIV_VER_1_12);
#undef __check_priv_csr
#define __check_ext_csr(__base_priv, __csr, __ext) \
if (hfeatures->priv_version >= __base_priv) { \
csr_read_allowed(__csr, (ulong)&trap); \
if (!trap.cause) \
__sbi_hart_update_extension(hfeatures, \
__ext, true); \
}
/* Counter overflow/filtering is not useful without mcounter/inhibit */
/* Detect if hart supports sscofpmf */
__check_ext_csr(SBI_HART_PRIV_VER_1_11,
CSR_SCOUNTOVF, SBI_HART_EXT_SSCOFPMF);
/* Detect if hart supports time CSR */
__check_ext_csr(SBI_HART_PRIV_VER_UNKNOWN,
CSR_TIME, SBI_HART_EXT_ZICNTR);
/* Detect if hart has AIA local interrupt CSRs */
__check_ext_csr(SBI_HART_PRIV_VER_UNKNOWN,
CSR_MTOPI, SBI_HART_EXT_SMAIA);
/* Detect if hart supports stimecmp CSR(Sstc extension) */
__check_ext_csr(SBI_HART_PRIV_VER_1_12,
CSR_STIMECMP, SBI_HART_EXT_SSTC);
/* Detect if hart supports mstateen CSRs */
__check_ext_csr(SBI_HART_PRIV_VER_1_12,
CSR_MSTATEEN0, SBI_HART_EXT_SMSTATEEN);
/* Detect if hart supports smcntrpmf */
__check_ext_csr(SBI_HART_PRIV_VER_1_12,
CSR_MCYCLECFG, SBI_HART_EXT_SMCNTRPMF);
/* Detect if hart support sdtrig (debug triggers) */
__check_ext_csr(SBI_HART_PRIV_VER_UNKNOWN,
CSR_TSELECT, SBI_HART_EXT_SDTRIG);
#undef __check_ext_csr
/* Save trap based detection of Zicntr */
has_zicntr = sbi_hart_has_extension(scratch, SBI_HART_EXT_ZICNTR);
/* Let platform populate extensions */
rc = sbi_platform_extensions_init(sbi_platform_thishart_ptr(),
hfeatures);
if (rc)
return rc;
/* Zicntr should only be detected using traps */
__sbi_hart_update_extension(hfeatures, SBI_HART_EXT_ZICNTR,
has_zicntr);
/* Extensions implied by other extensions and features */
if (hfeatures->mhpm_mask)
__sbi_hart_update_extension(hfeatures,
SBI_HART_EXT_ZIHPM, true);
/* Mark hart feature detection done */
hfeatures->detected = true;
/*
* On platforms with Smepmp, the previous booting stage must
* enter OpenSBI with mseccfg.MML == 0. This allows OpenSBI
* to configure it's own M-mode only regions without depending
* on the previous booting stage.
*/
if (sbi_hart_has_extension(scratch, SBI_HART_EXT_SMEPMP) &&
(csr_read(CSR_MSECCFG) & MSECCFG_MML))
return SBI_EILL;
return 0;
}
int sbi_hart_reinit(struct sbi_scratch *scratch)
{
int rc;
mstatus_init(scratch);
rc = fp_init(scratch);
if (rc)
return rc;
rc = delegate_traps(scratch);
if (rc)
return rc;
return 0;
}
int sbi_hart_init(struct sbi_scratch *scratch, bool cold_boot)
{
int rc;
/*
* Clear mip CSR before proceeding with init to avoid any spurious
* external interrupts in S-mode.
*/
csr_write(CSR_MIP, 0);
if (cold_boot) {
if (misa_extension('H'))
sbi_hart_expected_trap = &__sbi_expected_trap_hext;
hart_features_offset = sbi_scratch_alloc_offset(
sizeof(struct sbi_hart_features));
if (!hart_features_offset)
return SBI_ENOMEM;
}
rc = hart_detect_features(scratch);
if (rc)
return rc;
return sbi_hart_reinit(scratch);
}
void __attribute__((noreturn)) sbi_hart_hang(void)
{
while (1)
wfi();
__builtin_unreachable();
}
void __attribute__((noreturn))
sbi_hart_switch_mode(unsigned long arg0, unsigned long arg1,
unsigned long next_addr, unsigned long next_mode,
bool next_virt)
{
#if __riscv_xlen == 32
unsigned long val, valH;
#else
unsigned long val;
#endif
switch (next_mode) {
case PRV_M:
break;
case PRV_S:
if (!misa_extension('S'))
sbi_hart_hang();
break;
case PRV_U:
if (!misa_extension('U'))
sbi_hart_hang();
break;
default:
sbi_hart_hang();
}
val = csr_read(CSR_MSTATUS);
val = INSERT_FIELD(val, MSTATUS_MPP, next_mode);
val = INSERT_FIELD(val, MSTATUS_MPIE, 0);
#if __riscv_xlen == 32
if (misa_extension('H')) {
valH = csr_read(CSR_MSTATUSH);
valH = INSERT_FIELD(valH, MSTATUSH_MPV, next_virt);
csr_write(CSR_MSTATUSH, valH);
}
#else
if (misa_extension('H'))
val = INSERT_FIELD(val, MSTATUS_MPV, next_virt);
#endif
csr_write(CSR_MSTATUS, val);
csr_write(CSR_MEPC, next_addr);
if (next_mode == PRV_S) {
csr_write(CSR_STVEC, next_addr);
csr_write(CSR_SSCRATCH, 0);
csr_write(CSR_SIE, 0);
csr_write(CSR_SATP, 0);
} else if (next_mode == PRV_U) {
if (misa_extension('N')) {
csr_write(CSR_UTVEC, next_addr);
csr_write(CSR_USCRATCH, 0);
csr_write(CSR_UIE, 0);
}
}
register unsigned long a0 asm("a0") = arg0;
register unsigned long a1 asm("a1") = arg1;
__asm__ __volatile__("mret" : : "r"(a0), "r"(a1));
__builtin_unreachable();
}