riscv: sbi: Add support for sbi_cache_flush and sbi_cache_invalidate

This patch introduces the support for GMAC drivers to perform flush
and invalidate of L2 Cache:
* sbi_cache_invalidate(): Invalidate L2 cache for data passed from GMAC
to CPU
* sbi_cache_flush(): Flush L2 cache for data passed from CPU to GMAC

Signed-off-by: Genevieve Chan <genevieve.chan@starfivetech.com>

2 files changed, 38 insertions, 0 deletions

diff --git a/arch/riscv/include/asm/sbi.h b/arch/riscv/include/asm/sbi.h
index 9baddaee5623..043a56cc90c0 100644
--- a/arch/riscv/include/asm/sbi.h
+++ b/arch/riscv/include/asm/sbi.h
@@ -37,6 +37,7 @@ enum sbi_ext_id {
 
 	/* Vendor extensions must lie within this range */
 	SBI_EXT_VENDOR_START = 0x09000000,
+	SBI_EXT_CACHE = 0x09057485,
 	SBI_EXT_VENDOR_END = 0x09FFFFFF,
 };
 
@@ -137,6 +138,12 @@ union sbi_pmu_ctr_info {
 };
 
 #define RISCV_PMU_RAW_EVENT_MASK GENMASK_ULL(47, 0)
+
+enum sbi_ext_cache_fid {
+	SBI_EXT_BASE_L2_FLUSH = 0,
+	SBI_EXT_BASE_L2_INVALIDATE,
+};
+
 #define RISCV_PMU_RAW_EVENT_IDX 0x20000
 
 /** General pmu event codes specified in SBI PMU extension */
@@ -294,6 +301,8 @@ int sbi_remote_hfence_vvma_asid(const struct cpumask *cpu_mask,
 				unsigned long size,
 				unsigned long asid);
 long sbi_probe_extension(int ext);
+int sbi_cache_invalidate(unsigned long start, unsigned long len);
+int sbi_cache_flush(unsigned long start, unsigned long len);
 
 /* Check if current SBI specification version is 0.1 or not */
 static inline int sbi_spec_is_0_1(void)
diff --git a/arch/riscv/kernel/sbi.c b/arch/riscv/kernel/sbi.c
index ef4af31ed2e8..e7b14f0f7032 100644
--- a/arch/riscv/kernel/sbi.c
+++ b/arch/riscv/kernel/sbi.c
@@ -649,6 +649,35 @@ static const struct riscv_ipi_ops sbi_ipi_ops = {
 	.ipi_inject = sbi_send_cpumask_ipi
 };
 
+int sbi_cache_flush(unsigned long start, unsigned long len)
+{
+	struct sbiret ret;
+
+	ret = sbi_ecall(SBI_EXT_CACHE, SBI_EXT_BASE_L2_FLUSH,
+		start, len, 0, 0, 0, 0);
+	if (!ret.error)
+		if (ret.value)
+			return ret.value;
+
+	return -ENOTSUPP;
+}
+EXPORT_SYMBOL(sbi_cache_flush);
+
+int sbi_cache_invalidate(unsigned long start, unsigned long len)
+{
+
+	struct sbiret ret;
+
+	ret = sbi_ecall(SBI_EXT_CACHE, SBI_EXT_BASE_L2_INVALIDATE,
+		start, len, 0, 0, 0, 0);
+	if (!ret.error)
+		if (ret.value)
+			return ret.value;
+
+	return -ENOTSUPP;
+}
+EXPORT_SYMBOL(sbi_cache_invalidate);
+
 void __init sbi_init(void)
 {
 	int ret;