lib: sbi_scratch: Add sbi_hart_count() and for_each_hartindex()

There is currently no helper for iterating through the harts in a
system, and code must choose between sbi_scratch_last_hartindex() and
sbi_platform_hart_count() for the loop condition.

sbi_scratch_last_hartindex() has unusual semantics, leading to the
likelihood of off-by-one errors, and sbi_platform_hart_count() is
provided by the platform and so may not be properly bounded.

Add a new helper which definitively reports the number of harts managed
by this OpenSBI instance, i.e. the number of valid hart indexes, and a
convenient iterator macro.

Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
This commit is contained in:
Samuel Holland
2025-02-20 10:42:29 -08:00
committed by Anup Patel
parent 6b97950cf5
commit 757f7acafd
2 changed files with 16 additions and 13 deletions

View File

@@ -14,7 +14,7 @@
#include <sbi/sbi_scratch.h>
#include <sbi/sbi_string.h>
u32 last_hartindex_having_scratch = 0;
u32 sbi_scratch_hart_count;
u32 hartindex_to_hartid_table[SBI_HARTMASK_MAX_BITS] = { [0 ... SBI_HARTMASK_MAX_BITS-1] = -1U };
struct sbi_scratch *hartindex_to_scratch_table[SBI_HARTMASK_MAX_BITS];
@@ -23,9 +23,7 @@ static unsigned long extra_offset = SBI_SCRATCH_EXTRA_SPACE_OFFSET;
u32 sbi_hartid_to_hartindex(u32 hartid)
{
u32 i;
for (i = 0; i <= last_hartindex_having_scratch; i++)
sbi_for_each_hartindex(i)
if (hartindex_to_hartid_table[i] == hartid)
return i;
@@ -36,22 +34,21 @@ typedef struct sbi_scratch *(*hartid2scratch)(ulong hartid, ulong hartindex);
int sbi_scratch_init(struct sbi_scratch *scratch)
{
u32 i, h, hart_count;
u32 h, hart_count;
const struct sbi_platform *plat = sbi_platform_ptr(scratch);
hart_count = plat->hart_count;
if (hart_count > SBI_HARTMASK_MAX_BITS)
hart_count = SBI_HARTMASK_MAX_BITS;
sbi_scratch_hart_count = hart_count;
for (i = 0; i < hart_count; i++) {
sbi_for_each_hartindex(i) {
h = (plat->hart_index2id) ? plat->hart_index2id[i] : i;
hartindex_to_hartid_table[i] = h;
hartindex_to_scratch_table[i] =
((hartid2scratch)scratch->hartid_to_scratch)(h, i);
}
last_hartindex_having_scratch = hart_count - 1;
return 0;
}