lib: utils: Add detection of Smepmp from ISA string in FDT

- Add function to parse ISA string in FDT.
- Set Smepmp feature bit in extensions if "smepmp" string is found in ISA string.

Signed-off-by: Himanshu Chauhan <hchauhan@ventanamicro.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
This commit is contained in:
Himanshu Chauhan 2023-07-12 10:04:31 +05:30 committed by Anup Patel
parent cbcfc7b10c
commit d72f5f1747
3 changed files with 123 additions and 0 deletions

View file

@ -56,6 +56,9 @@ int fdt_parse_max_enabled_hart_id(void *fdt, u32 *max_hartid);
int fdt_parse_timebase_frequency(void *fdt, unsigned long *freq);
int fdt_parse_isa_extensions(void *fdt, unsigned int hard_id,
unsigned long *extensions);
int fdt_parse_gaisler_uart_node(void *fdt, int nodeoffset,
struct platform_uart_data *uart);

View file

@ -12,6 +12,7 @@
#include <sbi/sbi_hartmask.h>
#include <sbi/sbi_platform.h>
#include <sbi/sbi_scratch.h>
#include <sbi/sbi_hart.h>
#include <sbi_utils/fdt/fdt_helper.h>
#include <sbi_utils/irqchip/aplic.h>
#include <sbi_utils/irqchip/imsic.h>
@ -313,6 +314,116 @@ int fdt_parse_timebase_frequency(void *fdt, unsigned long *freq)
return 0;
}
static int fdt_get_isa_string(void *fdt, unsigned int hartid,
const char **isa_string)
{
int err, cpu_offset, cpus_offset, len;
u32 c_hartid;
const fdt32_t *val;
if (!fdt)
return SBI_EINVAL;
cpus_offset = fdt_path_offset(fdt, "/cpus");
if (cpus_offset < 0)
return cpus_offset;
fdt_for_each_subnode(cpu_offset, fdt, cpus_offset) {
err = fdt_parse_hart_id(fdt, cpu_offset, &c_hartid);
if (err)
continue;
if (!fdt_node_is_enabled(fdt, cpu_offset))
continue;
if (c_hartid == hartid) {
val = fdt_getprop(fdt, cpu_offset, "riscv,isa", &len);
if (val && len > 0) {
*isa_string = (const char *)val;
return 0;
}
}
}
return SBI_EINVAL;
}
#define RISCV_ISA_EXT_NAME_LEN_MAX 32
int fdt_parse_isa_extensions(void *fdt, unsigned int hartid,
unsigned long *extensions)
{
size_t i, j, isa_len;
char mstr[RISCV_ISA_EXT_NAME_LEN_MAX];
const char *isa = NULL;
if (fdt_get_isa_string(fdt, hartid, &isa))
return SBI_EINVAL;
if (!isa)
return SBI_EINVAL;
i = 0;
isa_len = strlen(isa);
if (isa[i] == 'r' || isa[i] == 'R')
i++;
else
return SBI_EINVAL;
if (isa[i] == 'v' || isa[i] == 'V')
i++;
else
return SBI_EINVAL;
if (isa[i] == '3' || isa[i+1] == '2')
i += 2;
else if (isa[i] == '6' || isa[i+1] == '4')
i += 2;
else
return SBI_EINVAL;
/* Skip base ISA extensions */
for (; i < isa_len; i++) {
if (isa[i] == '_')
break;
}
while (i < isa_len) {
if (isa[i] != '_') {
i++;
continue;
}
/* Skip the '_' character */
i++;
/* Extract the multi-letter extension name */
j = 0;
while ((i < isa_len) && (isa[i] != '_') &&
(j < (sizeof(mstr) - 1)))
mstr[j++] = isa[i++];
mstr[j] = '\0';
/* Skip empty multi-letter extension name */
if (!j)
continue;
#define SET_ISA_EXT_MAP(name, bit) \
do { \
if (!strcmp(mstr, name)) { \
__set_bit(bit, extensions); \
continue; \
} \
} while (false) \
SET_ISA_EXT_MAP("smepmp", SBI_HART_EXT_SMEPMP);
#undef SET_ISA_EXT_MAP
}
return 0;
}
static int fdt_parse_uart_node_common(void *fdt, int nodeoffset,
struct platform_uart_data *uart,
unsigned long default_freq,

View file

@ -211,6 +211,15 @@ static void generic_final_exit(void)
static int generic_extensions_init(struct sbi_hart_features *hfeatures)
{
int rc;
/* Parse the ISA string from FDT and enable the listed extensions */
rc = fdt_parse_isa_extensions(fdt_get_address(), current_hartid(),
&hfeatures->extensions);
if (rc)
return rc;
if (generic_plat && generic_plat->extensions_init)
return generic_plat->extensions_init(generic_plat_match,
hfeatures);