platform: generic: Optimize extensions_init() to parse ISA extensions once

Instead of parsing ISA extensions separately for each hart in the
generic_extensions_init() function, it is better to parse ISA extensions
for all available harts in the cold boot path. Also, this allows us
to remove fdt_isa_bitmap from scratch space and directly initialize
"extensions" in struct sbi_hart_features for each hart.

Signed-off-by: Anup Patel <anup.patel@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20260521082625.1520870-3-anup.patel@oss.qualcomm.com
Signed-off-by: Anup Patel <anup@brainfault.org>

include/sbi/sbi_platform.h

@@ -55,7 +55,6 @@
 struct sbi_domain_memregion;
 struct sbi_ecall_return;
 struct sbi_trap_regs;
-struct sbi_hart_features;
 union sbi_ldst_data;
 
 /** Possible feature flags of a platform */
@@ -105,7 +104,7 @@ struct sbi_platform_operations {
 	int (*misa_get_xlen)(void);
 
 	/** Initialize (or populate) HART extensions for the platform */
-	int (*extensions_init)(struct sbi_hart_features *hfeatures);
+	int (*extensions_init)(bool cold_boot);
 
 	/** Initialize (or populate) domains for the platform */
 	int (*domains_init)(void);
@@ -486,10 +485,10 @@ static inline int sbi_platform_misa_xlen(const struct sbi_platform *plat)
  */
 static inline int sbi_platform_extensions_init(
 					const struct sbi_platform *plat,
-					struct sbi_hart_features *hfeatures)
+					bool cold_boot)
 {
 	if (plat && sbi_platform_ops(plat)->extensions_init)
-		return sbi_platform_ops(plat)->extensions_init(hfeatures);
+		return sbi_platform_ops(plat)->extensions_init(cold_boot);
 	return 0;
 }
 

include/sbi_utils/fdt/fdt_helper.h

@@ -54,8 +54,7 @@ int fdt_parse_cbom_block_size(const void *fdt, int cpu_offset, unsigned long  *c
 
 int fdt_parse_timebase_frequency(const void *fdt, unsigned long *freq);
 
-int fdt_parse_isa_extensions(const void *fdt, unsigned int hartid,
-			     unsigned long *extensions);
+int fdt_parse_isa_extensions_all_harts(const void *fdt);
 
 int fdt_parse_gaisler_uart_node(const void *fdt, int nodeoffset,
 				struct platform_uart_data *uart);

lib/sbi/sbi_hart.c

@@ -508,7 +508,7 @@ static int hart_mhpm_get_allowed_bits(void)
 	return num_bits;
 }
 
-static int hart_detect_features(struct sbi_scratch *scratch)
+static int hart_detect_features(struct sbi_scratch *scratch, bool cold_boot)
 {
 	struct sbi_trap_info trap = {0};
 	struct sbi_hart_features *hfeatures =
@@ -525,8 +525,7 @@ static int hart_detect_features(struct sbi_scratch *scratch)
 	 * Needed to detect Smrnmi and install NMI handlers before CSR probes
 	 * that may trigger traps.
 	 */
-	rc = sbi_platform_extensions_init(sbi_platform_thishart_ptr(),
-					  hfeatures);
+	rc = sbi_platform_extensions_init(sbi_platform_ptr(scratch), cold_boot);
 	if (rc)
 		return rc;
 
@@ -764,7 +763,7 @@ int sbi_hart_init(struct sbi_scratch *scratch, bool cold_boot)
 			return SBI_ENOMEM;
 	}
 
-	rc = hart_detect_features(scratch);
+	rc = hart_detect_features(scratch, cold_boot);
 	if (rc)
 		return rc;
 

lib/utils/fdt/fdt_helper.c

@@ -328,8 +328,6 @@ int fdt_parse_timebase_frequency(const void *fdt, unsigned long *freq)
 
 #define RISCV_ISA_EXT_NAME_LEN_MAX	32
 
-static unsigned long fdt_isa_bitmap_offset;
-
 static int fdt_parse_isa_one_hart(const char *isa, unsigned long *extensions)
 {
 	size_t i, j, isa_len;
@@ -409,15 +407,15 @@ static void fdt_parse_isa_extensions_one_hart(const char *isa,
 	}
 }
 
-static int fdt_parse_isa_all_harts(const void *fdt)
+int fdt_parse_isa_extensions_all_harts(const void *fdt)
 {
 	u32 hartid;
 	const fdt32_t *val;
-	unsigned long *hart_exts;
 	struct sbi_scratch *scratch;
+	struct sbi_hart_features *hfeatures;
 	int err, cpu_offset, cpus_offset, len;
 
-	if (!fdt || !fdt_isa_bitmap_offset)
+	if (!fdt)
 		return SBI_EINVAL;
 
 	cpus_offset = fdt_path_offset(fdt, "/cpus");
@@ -436,13 +434,14 @@ static int fdt_parse_isa_all_harts(const void *fdt)
 		if (!scratch)
 			return SBI_ENOENT;
 
-		hart_exts = sbi_scratch_offset_ptr(scratch,
-						   fdt_isa_bitmap_offset);
+		hfeatures = sbi_hart_features_ptr(scratch);
+		if (!hfeatures)
+			return SBI_ENOENT;
 
 		val = fdt_getprop(fdt, cpu_offset, "riscv,isa-extensions", &len);
 		if (val && len > 0) {
 			fdt_parse_isa_extensions_one_hart((const char *)val,
-							  hart_exts, len);
+							  hfeatures->extensions, len);
 			continue;
 		}
 
@@ -450,7 +449,7 @@ static int fdt_parse_isa_all_harts(const void *fdt)
 		if (!val || len <= 0)
 			return SBI_ENOENT;
 
-		err = fdt_parse_isa_one_hart((const char *)val, hart_exts);
+		err = fdt_parse_isa_one_hart((const char *)val, hfeatures->extensions);
 		if (err)
 			return err;
 	}
@@ -458,36 +457,6 @@ static int fdt_parse_isa_all_harts(const void *fdt)
 	return 0;
 }
 
-int fdt_parse_isa_extensions(const void *fdt, unsigned int hartid,
-			unsigned long *extensions)
-{
-	int rc, i;
-	unsigned long *hart_exts;
-	struct sbi_scratch *scratch;
-
-	if (!fdt_isa_bitmap_offset) {
-		fdt_isa_bitmap_offset = sbi_scratch_alloc_offset(
-					sizeof(*hart_exts) *
-					BITS_TO_LONGS(SBI_HART_EXT_MAX));
-		if (!fdt_isa_bitmap_offset)
-			return SBI_ENOMEM;
-
-		rc = fdt_parse_isa_all_harts(fdt);
-		if (rc)
-			return rc;
-	}
-
-	scratch = sbi_hartid_to_scratch(hartid);
-	if (!scratch)
-		return SBI_ENOENT;
-
-	hart_exts = sbi_scratch_offset_ptr(scratch, fdt_isa_bitmap_offset);
-
-	for (i = 0; i < BITS_TO_LONGS(SBI_HART_EXT_MAX); i++)
-		extensions[i] |= hart_exts[i];
-	return 0;
-}
-
 static int fdt_parse_uart_node_common(const void *fdt, int nodeoffset,
 				      struct platform_uart_data *uart,
 				      unsigned long default_freq,

platform/generic/allwinner/sun20i-d1.c

@@ -12,6 +12,7 @@
 #include <sbi/sbi_bitops.h>
 #include <sbi/sbi_ecall_interface.h>
 #include <sbi/sbi_error.h>
+#include <sbi/sbi_hart.h>
 #include <sbi/sbi_hsm.h>
 #include <sbi/sbi_platform.h>
 #include <sbi/sbi_pmu.h>
@@ -197,11 +198,12 @@ static int sun20i_d1_final_init(bool cold_boot)
 	return generic_final_init(cold_boot);
 }
 
-static int sun20i_d1_extensions_init(struct sbi_hart_features *hfeatures)
+static int sun20i_d1_extensions_init(bool cold_boot)
 {
+	struct sbi_hart_features *hfeatures;
 	int rc;
 
-	rc = generic_extensions_init(hfeatures);
+	rc = generic_extensions_init(cold_boot);
 	if (rc)
 		return rc;
 
@@ -209,6 +211,7 @@ static int sun20i_d1_extensions_init(struct sbi_hart_features *hfeatures)
 
 	/* auto-detection doesn't work on t-head c9xx cores */
 	/* D1 has 29 mhpmevent csrs, but only 3-9,13-17 have valid value */
+	hfeatures = sbi_hart_features_ptr(sbi_scratch_thishart_ptr());
 	hfeatures->mhpm_mask = 0x0003e3f8;
 	hfeatures->mhpm_bits = 64;
 

platform/generic/andes/andes_pmu.c

@@ -9,6 +9,7 @@
 #include <andes/andes_pmu.h>
 #include <sbi/sbi_bitops.h>
 #include <sbi/sbi_error.h>
+#include <sbi/sbi_hart.h>
 #include <sbi/sbi_pmu.h>
 #include <libfdt.h>
 #include <platform_override.h>
@@ -58,12 +59,12 @@ static struct sbi_pmu_device andes_pmu = {
 	.hw_counter_filter_mode = andes_hw_counter_filter_mode
 };
 
-int andes_pmu_extensions_init(struct sbi_hart_features *hfeatures)
+int andes_pmu_extensions_init(bool cold_boot)
 {
 	struct sbi_scratch *scratch = sbi_scratch_thishart_ptr();
 	int rc;
 
-	rc = generic_extensions_init(hfeatures);
+	rc = generic_extensions_init(cold_boot);
 	if (rc)
 		return rc;
 

platform/generic/eswin/eic770x.c

@@ -10,6 +10,7 @@
 #include <sbi/sbi_console.h>
 #include <sbi/sbi_system.h>
 #include <sbi/sbi_math.h>
+#include <sbi/sbi_hart.h>
 #include <sbi/sbi_hart_pmp.h>
 #include <sbi/sbi_hart_protection.h>
 #include <eswin/eic770x.h>

platform/generic/include/andes/andes_pmu.h

@@ -7,9 +7,9 @@
 #ifndef _RISCV_ANDES_PMU_H
 #define _RISCV_ANDES_PMU_H
 
-#include <sbi/sbi_hart.h>
+#include <sbi/sbi_types.h>
 
 int andes_pmu_init(void);
-int andes_pmu_extensions_init(struct sbi_hart_features *hfeatures);
+int andes_pmu_extensions_init(bool cold_boot);
 
 #endif /* _RISCV_ANDES_PMU_H */

platform/generic/include/platform_override.h

@@ -10,7 +10,6 @@
 #ifndef __PLATFORM_OVERRIDE_H__
 #define __PLATFORM_OVERRIDE_H__
 
-#include <sbi/sbi_hart.h>
 #include <sbi/sbi_platform.h>
 #include <sbi/sbi_types.h>
 #include <sbi_utils/fdt/fdt_driver.h>
@@ -19,7 +18,7 @@ bool generic_cold_boot_allowed(u32 hartid);
 int generic_nascent_init(void);
 int generic_early_init(bool cold_boot);
 int generic_final_init(bool cold_boot);
-int generic_extensions_init(struct sbi_hart_features *hfeatures);
+int generic_extensions_init(bool cold_boot);
 int generic_domains_init(void);
 int generic_pmu_init(void);
 uint64_t generic_pmu_xlate_to_mhpmevent(uint32_t event_idx, uint64_t data);

platform/generic/platform.c

@@ -253,11 +253,13 @@ int generic_final_init(bool cold_boot)
 	return 0;
 }
 
-int generic_extensions_init(struct sbi_hart_features *hfeatures)
+int generic_extensions_init(bool cold_boot)
 {
+	if (!cold_boot)
+		return 0;
+
 	/* Parse the ISA string from FDT and enable the listed extensions */
-	return fdt_parse_isa_extensions(fdt_get_address(), current_hartid(),
-					hfeatures->extensions);
+	return fdt_parse_isa_extensions_all_harts(fdt_get_address());
 }
 
 int generic_domains_init(void)

platform/generic/sophgo/sg2042.c

@@ -49,11 +49,11 @@ static int sophgo_sg2042_early_init(bool cold_boot)
 	return 0;
 }
 
-static int sophgo_sg2042_extensions_init(struct sbi_hart_features *hfeatures)
+static int sophgo_sg2042_extensions_init(bool cold_boot)
 {
 	int rc;
 
-	rc = generic_extensions_init(hfeatures);
+	rc = generic_extensions_init(cold_boot);
 	if (rc)
 		return rc;
 

platform/generic/starfive/jh7110.c

@@ -12,6 +12,7 @@
 #include <platform_override.h>
 #include <sbi/sbi_error.h>
 #include <sbi/sbi_bitops.h>
+#include <sbi/sbi_hart.h>
 #include <sbi/sbi_system.h>
 #include <sbi/sbi_console.h>
 #include <sbi/sbi_timer.h>

platform/generic/thead/thead-generic.c

@@ -26,11 +26,11 @@ static int thead_tlb_flush_early_init(bool cold_boot)
 	return generic_early_init(cold_boot);
 }
 
-static int thead_pmu_extensions_init(struct sbi_hart_features *hfeatures)
+static int thead_pmu_extensions_init(bool cold_boot)
 {
 	int rc;
 
-	rc = generic_extensions_init(hfeatures);
+	rc = generic_extensions_init(cold_boot);
 	if (rc)
 		return rc;