[PATCH 3/7] platform: generic/andes: pair non-retentive CSR save/restore with a flag

[Ben Zong-You Xie]

The restore was gated on sbi_init_count() and the current sleep type,
which is only a proxy for "did this hart actually save its CSRs". Track
it explicitly instead, so restore is self-guarding and the call site
needs no conditions.

Signed-off-by: Ben Zong-You Xie <ben717 at andestech.com>
---
 platform/generic/andes/ae350.c         | 18 ++++++++++++------
 platform/generic/include/andes/andes.h |  3 +++
 2 files changed, 15 insertions(+), 6 deletions(-)

diff --git a/platform/generic/andes/ae350.c b/platform/generic/andes/ae350.c
index 4cf7e26def54..4a053f434272 100644
--- a/platform/generic/andes/ae350.c
+++ b/platform/generic/andes/ae350.c
@@ -34,6 +34,8 @@ void ae350_non_ret_save(struct sbi_scratch *scratch)
 	andes_hdata->pmacfg2 = csr_read_num(CSR_PMACFG0 + 2);
 	for (int i = 0; i < 16; i++)
 		andes_hdata->pmaaddrX[i] = csr_read_num(CSR_PMAADDR0 + i);
+
+	andes_hdata->saved = true;
 }
 
 void ae350_non_ret_restore(struct sbi_scratch *scratch)
@@ -41,6 +43,9 @@ void ae350_non_ret_restore(struct sbi_scratch *scratch)
 	struct andes_hart_data *andes_hdata = sbi_scratch_offset_ptr(scratch,
 								     andes_hart_data_offset);
 
+	if (!andes_hdata->saved)
+		return;
+
 	csr_write(CSR_MCACHE_CTL, andes_hdata->mcache_ctl);
 	csr_write(CSR_MMISC_CTL, andes_hdata->mmisc_ctl);
 	csr_write(CSR_MPFT_CTL, andes_hdata->mpft_ctl);
@@ -52,6 +57,8 @@ void ae350_non_ret_restore(struct sbi_scratch *scratch)
 	csr_write_num(CSR_PMACFG0 + 2, andes_hdata->pmacfg2);
 	for (int i = 0; i < 16; i++)
 		csr_write_num(CSR_PMAADDR0 + i, andes_hdata->pmaaddrX[i]);
+
+	andes_hdata->saved = false;
 }
 
 void ae350_enable_coherency_warmboot(void)
@@ -62,18 +69,17 @@ void ae350_enable_coherency_warmboot(void)
 
 static int ae350_early_init(bool cold_boot)
 {
-	u32 hartid = current_hartid();
-	u32 sleep_type = atcsmu_get_sleep_type(hartid);
-
 	if (cold_boot) {
 		andes_hart_data_offset = sbi_scratch_alloc_offset(sizeof(struct andes_hart_data));
 		if (!andes_hart_data_offset)
 			return SBI_ENOMEM;
 	}
 
-	/* Don't restore Andes CSRs during boot or wake up from light sleep */
-	if (sbi_init_count(current_hartindex()) && sleep_type == SBI_SUSP_SLEEP_TYPE_SUSPEND)
-		ae350_non_ret_restore(sbi_scratch_thishart_ptr());
+	/*
+	 * This is a no-op unless this hart actually saved them, so it is safe
+	 * to call on every path.
+	 */
+	ae350_non_ret_restore(sbi_scratch_thishart_ptr());
 
 	return generic_early_init(cold_boot);
 }
diff --git a/platform/generic/include/andes/andes.h b/platform/generic/include/andes/andes.h
index dd2451718d00..dae112ce741f 100644
--- a/platform/generic/include/andes/andes.h
+++ b/platform/generic/include/andes/andes.h
@@ -96,6 +96,9 @@ struct andes_hart_data {
 	unsigned long pmacfg0;
 	unsigned long pmacfg2;
 	unsigned long pmaaddrX[16];
+
+	/* Set when the CSRs above hold a saved copy awaiting restore */
+	bool saved;
 };
 
 void ae350_non_ret_save(struct sbi_scratch *scratch);
-- 
2.34.1