[PATCH 4/6] lib: sbi: Add detection of Smepmp from ISA string in FDT
Himanshu Chauhan
hchauhan at ventanamicro.com
Tue Jun 20 07:32:10 PDT 2023
- To enable Smepmp, the ISA string in FDT should have "smepmp" string. This patch
adds support for parsing of Smepmp in ISA string.
- A bit is reserved for Smepmp in extensions member of sbi_hart_features
which is set if Smepmp is detected in FDT.
- A utilty function is added to check if Smepmp is detected and enabled.
- In sbi_boot_print_hart, a print is added to display the state of Smepmp.
Signed-off-by: Himanshu Chauhan <hchauhan at ventanamicro.com>
---
include/sbi/sbi_hart.h | 3 +
include/sbi_utils/fdt/fdt_helper.h | 3 +
lib/sbi/sbi_hart.c | 8 +++
lib/sbi/sbi_init.c | 2 +
lib/utils/fdt/fdt_helper.c | 111 +++++++++++++++++++++++++++++
platform/generic/platform.c | 5 ++
6 files changed, 132 insertions(+)
diff --git a/include/sbi/sbi_hart.h b/include/sbi/sbi_hart.h
index 95b40e7..9582b52 100644
--- a/include/sbi/sbi_hart.h
+++ b/include/sbi/sbi_hart.h
@@ -36,6 +36,8 @@ enum sbi_hart_extensions {
SBI_HART_EXT_SMSTATEEN,
/** HART has Sstc extension */
SBI_HART_EXT_SSTC,
+ /** HART has Smepmp */
+ SBI_HART_EXT_SMEPMP,
/** Maximum index of Hart extension */
SBI_HART_EXT_MAX,
@@ -66,6 +68,7 @@ static inline ulong sbi_hart_expected_trap_addr(void)
unsigned int sbi_hart_mhpm_count(struct sbi_scratch *scratch);
void sbi_hart_delegation_dump(struct sbi_scratch *scratch,
const char *prefix, const char *suffix);
+unsigned int sbi_hart_smepmp_supported(struct sbi_scratch *scratch);
unsigned int sbi_hart_pmp_count(struct sbi_scratch *scratch);
unsigned long sbi_hart_pmp_granularity(struct sbi_scratch *scratch);
unsigned int sbi_hart_pmp_addrbits(struct sbi_scratch *scratch);
diff --git a/include/sbi_utils/fdt/fdt_helper.h b/include/sbi_utils/fdt/fdt_helper.h
index 39d7f3a..5c928ff 100644
--- a/include/sbi_utils/fdt/fdt_helper.h
+++ b/include/sbi_utils/fdt/fdt_helper.h
@@ -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);
diff --git a/lib/sbi/sbi_hart.c b/lib/sbi/sbi_hart.c
index 6e52cbd..c328243 100644
--- a/lib/sbi/sbi_hart.c
+++ b/lib/sbi/sbi_hart.c
@@ -260,6 +260,14 @@ unsigned int sbi_hart_pmp_count(struct sbi_scratch *scratch)
return hfeatures->pmp_count;
}
+unsigned int sbi_hart_smepmp_supported(struct sbi_scratch *scratch)
+{
+ struct sbi_hart_features *hfeatures =
+ sbi_scratch_offset_ptr(scratch, hart_features_offset);
+
+ return !!(hfeatures->extensions & (_UL(1) << SBI_HART_EXT_SMEPMP));
+}
+
unsigned long sbi_hart_pmp_granularity(struct sbi_scratch *scratch)
{
struct sbi_hart_features *hfeatures =
diff --git a/lib/sbi/sbi_init.c b/lib/sbi/sbi_init.c
index 423e6d8..31d2c3e 100644
--- a/lib/sbi/sbi_init.c
+++ b/lib/sbi/sbi_init.c
@@ -173,6 +173,8 @@ static void sbi_boot_print_hart(struct sbi_scratch *scratch, u32 hartid)
misa_string(xlen, str, sizeof(str));
sbi_printf("Boot HART Base ISA : %s\n", str);
sbi_hart_get_extensions_str(scratch, str, sizeof(str));
+ sbi_printf("SMEPMP : %sDetected\n",
+ (sbi_hart_smepmp_supported(scratch) ? "" : "Not "));
sbi_printf("Boot HART ISA Extensions : %s\n", str);
sbi_printf("Boot HART PMP Count : %d\n",
sbi_hart_pmp_count(scratch));
diff --git a/lib/utils/fdt/fdt_helper.c b/lib/utils/fdt/fdt_helper.c
index a88a4ba..db9d4c3 100644
--- a/lib/utils/fdt/fdt_helper.c
+++ b/lib/utils/fdt/fdt_helper.c
@@ -12,6 +12,7 @@
#include <sbi/sbi_hartmask.h>
#include <sbi/sbi_platform.h>
#include <sbi/sbi_scratch.h>
+#include <sbi/sbi_hart.h> /* for hart extension enums */
#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 extentions */
+ 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,
diff --git a/platform/generic/platform.c b/platform/generic/platform.c
index 0c9cd95..24c0fa9 100644
--- a/platform/generic/platform.c
+++ b/platform/generic/platform.c
@@ -215,6 +215,11 @@ static int generic_extensions_init(struct sbi_hart_features *hfeatures)
return generic_plat->extensions_init(generic_plat_match,
hfeatures);
+ /* Parse the ISA string from FDT and enable the listed extensions */
+ if (fdt_parse_isa_extensions(fdt_get_address(), current_hartid(),
+ &hfeatures->extensions))
+ return 0;
+
return 0;
}
--
2.34.1
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