[PATCH] lib: utils: fdt_helper: simplify fdt_parse_isa_extensions() helper

[Yu-Chien Peter Lin]

The fdt_isa_bitmap was previously used as a temporary array
to store ISA extensions when parsing device-tree.
To reduce scratch space consumption, set the ISA bitmap
directly in hfeature->extensions, allows us to remove the
fdt_parse_isa_all_harts() as fdt_parse_isa_extensions() can
now handle the task directly.

This change makes the helper function more versatile, even
before scratch space is initialized.

Signed-off-by: Yu-Chien Peter Lin <peter.lin at sifive.com>
---
 include/sbi_utils/fdt/fdt_helper.h |  3 +-
 lib/utils/fdt/fdt_helper.c         | 45 ++----------------------------
 platform/generic/platform.c        |  2 +-
 3 files changed, 4 insertions(+), 46 deletions(-)

diff --git a/include/sbi_utils/fdt/fdt_helper.h b/include/sbi_utils/fdt/fdt_helper.h
index 04c850cc..24ad1a94 100644
--- a/include/sbi_utils/fdt/fdt_helper.h
+++ b/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(const void *fdt, unsigned long *hart_exts);
 
 int fdt_parse_gaisler_uart_node(const void *fdt, int nodeoffset,
 				struct platform_uart_data *uart);
diff --git a/lib/utils/fdt/fdt_helper.c b/lib/utils/fdt/fdt_helper.c
index 0f4859c1..61a5962c 100644
--- a/lib/utils/fdt/fdt_helper.c
+++ b/lib/utils/fdt/fdt_helper.c
@@ -324,8 +324,6 @@ 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;
@@ -405,15 +403,13 @@ 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(const void *fdt, unsigned long *hart_exts)
 {
 	u32 hartid;
 	const fdt32_t *val;
-	unsigned long *hart_exts;
-	struct sbi_scratch *scratch;
 	int err, cpu_offset, cpus_offset, len;
 
-	if (!fdt || !fdt_isa_bitmap_offset)
+	if (!fdt || !hart_exts)
 		return SBI_EINVAL;
 
 	cpus_offset = fdt_path_offset(fdt, "/cpus");
@@ -428,13 +424,6 @@ static int fdt_parse_isa_all_harts(const void *fdt)
 		if (!fdt_node_is_enabled(fdt, cpu_offset))
 			continue;
 
-		scratch = sbi_hartid_to_scratch(hartid);
-		if (!scratch)
-			return SBI_ENOENT;
-
-		hart_exts = sbi_scratch_offset_ptr(scratch,
-						   fdt_isa_bitmap_offset);
-
 		val = fdt_getprop(fdt, cpu_offset, "riscv,isa-extensions", &len);
 		if (val && len > 0) {
 			fdt_parse_isa_extensions_one_hart((const char *)val,
@@ -454,36 +443,6 @@ 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,
diff --git a/platform/generic/platform.c b/platform/generic/platform.c
index 47e771ad..2e8c6051 100644
--- a/platform/generic/platform.c
+++ b/platform/generic/platform.c
@@ -251,7 +251,7 @@ int generic_final_init(bool cold_boot)
 int generic_extensions_init(struct sbi_hart_features *hfeatures)
 {
 	/* Parse the ISA string from FDT and enable the listed extensions */
-	return fdt_parse_isa_extensions(fdt_get_address(), current_hartid(),
+	return fdt_parse_isa_extensions(fdt_get_address(),
 					hfeatures->extensions);
 }
 
-- 
2.48.0