RISC-V: Implement new SBI v0.2 extensions

Few v0.1 SBI calls are being replaced by new SBI calls that follows v0.2
calling convention.

Implement the replacement extensions and few additional new SBI function calls
that makes way for a better SBI interface in future.
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

arch/riscv/include/asm/sbi.h

@@ -96,6 +96,20 @@ void sbi_remote_sfence_vma_asid(const unsigned long *hart_mask,
 				unsigned long start,
 				unsigned long size,
 				unsigned long asid);
+int sbi_remote_hfence_gvma(const unsigned long *hart_mask,
+			   unsigned long start,
+			   unsigned long size);
+int sbi_remote_hfence_gvma_vmid(const unsigned long *hart_mask,
+				unsigned long start,
+				unsigned long size,
+				unsigned long vmid);
+int sbi_remote_hfence_vvma(const unsigned long *hart_mask,
+			   unsigned long start,
+			   unsigned long size);
+int sbi_remote_hfence_vvma_asid(const unsigned long *hart_mask,
+				unsigned long start,
+				unsigned long size,
+				unsigned long asid);
 int sbi_probe_extension(int ext);
 
 /* Check if current SBI specification version is 0.1 or not */

arch/riscv/include/asm/smp.h

@@ -61,5 +61,12 @@ static inline unsigned long cpuid_to_hartid_map(int cpu)
 	return boot_cpu_hartid;
 }
 
+static inline void riscv_cpuid_to_hartid_mask(const struct cpumask *in,
+					      struct cpumask *out)
+{
+	cpumask_clear(out);
+	cpumask_set_cpu(boot_cpu_hartid, out);
+}
+
 #endif /* CONFIG_SMP */
 #endif /* _ASM_RISCV_SMP_H */

arch/riscv/kernel/sbi.c

@@ -8,6 +8,7 @@
 #include <linux/init.h>
 #include <linux/pm.h>
 #include <asm/sbi.h>
+#include <asm/smp.h>
 
 /* default SBI version is 0.1 */
 unsigned long sbi_spec_version = SBI_SPEC_VERSION_DEFAULT;
@@ -191,6 +192,153 @@ static int __sbi_rfence_v01(int fid, const unsigned long *hart_mask,
 }
 #endif /* CONFIG_RISCV_SBI_V01 */
 
+static void __sbi_set_timer_v02(uint64_t stime_value)
+{
+#if __riscv_xlen == 32
+	sbi_ecall(SBI_EXT_TIME, SBI_EXT_TIME_SET_TIMER, stime_value,
+		  stime_value >> 32, 0, 0, 0, 0);
+#else
+	sbi_ecall(SBI_EXT_TIME, SBI_EXT_TIME_SET_TIMER, stime_value, 0,
+		  0, 0, 0, 0);
+#endif
+}
+
+static int __sbi_send_ipi_v02(const unsigned long *hart_mask)
+{
+	unsigned long hartid, hmask_val, hbase;
+	struct cpumask tmask;
+	struct sbiret ret = {0};
+	int result;
+
+	if (!hart_mask || !(*hart_mask)) {
+		riscv_cpuid_to_hartid_mask(cpu_online_mask, &tmask);
+		hart_mask = cpumask_bits(&tmask);
+	}
+
+	hmask_val = 0;
+	hbase = 0;
+	for_each_set_bit(hartid, hart_mask, NR_CPUS) {
+		if (hmask_val && ((hbase + BITS_PER_LONG) <= hartid)) {
+			ret = sbi_ecall(SBI_EXT_IPI, SBI_EXT_IPI_SEND_IPI,
+					hmask_val, hbase, 0, 0, 0, 0);
+			if (ret.error)
+				goto ecall_failed;
+			hmask_val = 0;
+			hbase = 0;
+		}
+		if (!hmask_val)
+			hbase = hartid;
+		hmask_val |= 1UL << (hartid - hbase);
+	}
+
+	if (hmask_val) {
+		ret = sbi_ecall(SBI_EXT_IPI, SBI_EXT_IPI_SEND_IPI,
+				hmask_val, hbase, 0, 0, 0, 0);
+		if (ret.error)
+			goto ecall_failed;
+	}
+
+	return 0;
+
+ecall_failed:
+	result = sbi_err_map_linux_errno(ret.error);
+	pr_err("%s: hbase = [%lu] hmask = [0x%lx] failed (error [%d])\n",
+	       __func__, hbase, hmask_val, result);
+	return result;
+}
+
+static int __sbi_rfence_v02_call(unsigned long fid, unsigned long hmask_val,
+				 unsigned long hbase, unsigned long start,
+				 unsigned long size, unsigned long arg4,
+				 unsigned long arg5)
+{
+	struct sbiret ret = {0};
+	int ext = SBI_EXT_RFENCE;
+	int result = 0;
+
+	switch (fid) {
+	case SBI_EXT_RFENCE_REMOTE_FENCE_I:
+		ret = sbi_ecall(ext, fid, hmask_val, hbase, 0, 0, 0, 0);
+		break;
+	case SBI_EXT_RFENCE_REMOTE_SFENCE_VMA:
+		ret = sbi_ecall(ext, fid, hmask_val, hbase, start,
+				size, 0, 0);
+		break;
+	case SBI_EXT_RFENCE_REMOTE_SFENCE_VMA_ASID:
+		ret = sbi_ecall(ext, fid, hmask_val, hbase, start,
+				size, arg4, 0);
+		break;
+
+	case SBI_EXT_RFENCE_REMOTE_HFENCE_GVMA:
+		ret = sbi_ecall(ext, fid, hmask_val, hbase, start,
+				size, 0, 0);
+		break;
+	case SBI_EXT_RFENCE_REMOTE_HFENCE_GVMA_VMID:
+		ret = sbi_ecall(ext, fid, hmask_val, hbase, start,
+				size, arg4, 0);
+		break;
+	case SBI_EXT_RFENCE_REMOTE_HFENCE_VVMA:
+		ret = sbi_ecall(ext, fid, hmask_val, hbase, start,
+				size, 0, 0);
+		break;
+	case SBI_EXT_RFENCE_REMOTE_HFENCE_VVMA_ASID:
+		ret = sbi_ecall(ext, fid, hmask_val, hbase, start,
+				size, arg4, 0);
+		break;
+	default:
+		pr_err("unknown function ID [%lu] for SBI extension [%d]\n",
+		       fid, ext);
+		result = -EINVAL;
+	}
+
+	if (ret.error) {
+		result = sbi_err_map_linux_errno(ret.error);
+		pr_err("%s: hbase = [%lu] hmask = [0x%lx] failed (error [%d])\n",
+		       __func__, hbase, hmask_val, result);
+	}
+
+	return result;
+}
+
+static int __sbi_rfence_v02(int fid, const unsigned long *hart_mask,
+			    unsigned long start, unsigned long size,
+			    unsigned long arg4, unsigned long arg5)
+{
+	unsigned long hmask_val, hartid, hbase;
+	struct cpumask tmask;
+	int result;
+
+	if (!hart_mask || !(*hart_mask)) {
+		riscv_cpuid_to_hartid_mask(cpu_online_mask, &tmask);
+		hart_mask = cpumask_bits(&tmask);
+	}
+
+	hmask_val = 0;
+	hbase = 0;
+	for_each_set_bit(hartid, hart_mask, NR_CPUS) {
+		if (hmask_val && ((hbase + BITS_PER_LONG) <= hartid)) {
+			result = __sbi_rfence_v02_call(fid, hmask_val, hbase,
+						       start, size, arg4, arg5);
+			if (result)
+				return result;
+			hmask_val = 0;
+			hbase = 0;
+		}
+		if (!hmask_val)
+			hbase = hartid;
+		hmask_val |= 1UL << (hartid - hbase);
+	}
+
+	if (hmask_val) {
+		result = __sbi_rfence_v02_call(fid, hmask_val, hbase,
+					       start, size, arg4, arg5);
+		if (result)
+			return result;
+	}
+
+	return 0;
+}
+
 /**
  * sbi_set_timer() - Program the timer for next timer event.
  * @stime_value: The value after which next timer event should fire.
@@ -266,6 +414,85 @@ void sbi_remote_sfence_vma_asid(const unsigned long *hart_mask,
 }
 EXPORT_SYMBOL(sbi_remote_sfence_vma_asid);
 
+/**
+ * sbi_remote_hfence_gvma() - Execute HFENCE.GVMA instructions on given remote
+ *			   harts for the specified guest physical address range.
+ * @hart_mask: A cpu mask containing all the target harts.
+ * @start: Start of the guest physical address
+ * @size: Total size of the guest physical address range.
+ *
+ * Return: None
+ */
+int sbi_remote_hfence_gvma(const unsigned long *hart_mask,
+			   unsigned long start,
+			   unsigned long size)
+{
+	return __sbi_rfence(SBI_EXT_RFENCE_REMOTE_HFENCE_GVMA,
+			    hart_mask, start, size, 0, 0);
+}
+EXPORT_SYMBOL_GPL(sbi_remote_hfence_gvma);
+
+/**
+ * sbi_remote_hfence_gvma_vmid() - Execute HFENCE.GVMA instructions on given
+ * remote harts for a guest physical address range belonging to a specific VMID.
+ *
+ * @hart_mask: A cpu mask containing all the target harts.
+ * @start: Start of the guest physical address
+ * @size: Total size of the guest physical address range.
+ * @vmid: The value of guest ID (VMID).
+ *
+ * Return: 0 if success, Error otherwise.
+ */
+int sbi_remote_hfence_gvma_vmid(const unsigned long *hart_mask,
+				unsigned long start,
+				unsigned long size,
+				unsigned long vmid)
+{
+	return __sbi_rfence(SBI_EXT_RFENCE_REMOTE_HFENCE_GVMA_VMID,
+			    hart_mask, start, size, vmid, 0);
+}
+EXPORT_SYMBOL(sbi_remote_hfence_gvma_vmid);
+
+/**
+ * sbi_remote_hfence_vvma() - Execute HFENCE.VVMA instructions on given remote
+ *			     harts for the current guest virtual address range.
+ * @hart_mask: A cpu mask containing all the target harts.
+ * @start: Start of the current guest virtual address
+ * @size: Total size of the current guest virtual address range.
+ *
+ * Return: None
+ */
+int sbi_remote_hfence_vvma(const unsigned long *hart_mask,
+			   unsigned long start,
+			   unsigned long size)
+{
+	return __sbi_rfence(SBI_EXT_RFENCE_REMOTE_HFENCE_VVMA,
+			    hart_mask, start, size, 0, 0);
+}
+EXPORT_SYMBOL(sbi_remote_hfence_vvma);
+
+/**
+ * sbi_remote_hfence_vvma_asid() - Execute HFENCE.VVMA instructions on given
+ * remote harts for current guest virtual address range belonging to a specific
+ * ASID.
+ *
+ * @hart_mask: A cpu mask containing all the target harts.
+ * @start: Start of the current guest virtual address
+ * @size: Total size of the current guest virtual address range.
+ * @asid: The value of address space identifier (ASID).
+ *
+ * Return: None
+ */
+int sbi_remote_hfence_vvma_asid(const unsigned long *hart_mask,
+				unsigned long start,
+				unsigned long size,
+				unsigned long asid)
+{
+	return __sbi_rfence(SBI_EXT_RFENCE_REMOTE_HFENCE_VVMA_ASID,
+			    hart_mask, start, size, asid, 0);
+}
+EXPORT_SYMBOL(sbi_remote_hfence_vvma_asid);
+
 /**
  * sbi_probe_extension() - Check if an SBI extension ID is supported or not.
  * @extid: The extension ID to be probed.
@@ -332,11 +559,29 @@ int __init sbi_init(void)
 	if (!sbi_spec_is_0_1()) {
 		pr_info("SBI implementation ID=0x%lx Version=0x%lx\n",
 			sbi_get_firmware_id(), sbi_get_firmware_version());
+		if (sbi_probe_extension(SBI_EXT_TIME) > 0) {
+			__sbi_set_timer = __sbi_set_timer_v02;
+			pr_info("SBI v0.2 TIME extension detected\n");
+		} else {
+			__sbi_set_timer = __sbi_set_timer_v01;
+		}
+		if (sbi_probe_extension(SBI_EXT_IPI) > 0) {
+			__sbi_send_ipi	= __sbi_send_ipi_v02;
+			pr_info("SBI v0.2 IPI extension detected\n");
+		} else {
+			__sbi_send_ipi	= __sbi_send_ipi_v01;
+		}
+		if (sbi_probe_extension(SBI_EXT_RFENCE) > 0) {
+			__sbi_rfence	= __sbi_rfence_v02;
+			pr_info("SBI v0.2 RFENCE extension detected\n");
+		} else {
+			__sbi_rfence	= __sbi_rfence_v01;
+		}
+	} else {
+		__sbi_set_timer = __sbi_set_timer_v01;
+		__sbi_send_ipi	= __sbi_send_ipi_v01;
+		__sbi_rfence	= __sbi_rfence_v01;
 	}
 
-	__sbi_set_timer = __sbi_set_timer_v01;
-	__sbi_send_ipi	= __sbi_send_ipi_v01;
-	__sbi_rfence	= __sbi_rfence_v01;
-
 	return 0;
 }