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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-08-07 13:11:22 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-08-07 13:11:22 +0000
commitb20732900e4636a467c0183a47f7396700f5f743 (patch)
tree42f079ff82e701ebcb76829974b4caca3e5b6798 /drivers/acpi/riscv/cppc.c
parentAdding upstream version 6.8.12. (diff)
downloadlinux-b20732900e4636a467c0183a47f7396700f5f743.tar.xz
linux-b20732900e4636a467c0183a47f7396700f5f743.zip
Adding upstream version 6.9.7.upstream/6.9.7
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/acpi/riscv/cppc.c')
-rw-r--r--drivers/acpi/riscv/cppc.c157
1 files changed, 157 insertions, 0 deletions
diff --git a/drivers/acpi/riscv/cppc.c b/drivers/acpi/riscv/cppc.c
new file mode 100644
index 0000000000..4cdff387de
--- /dev/null
+++ b/drivers/acpi/riscv/cppc.c
@@ -0,0 +1,157 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Implement CPPC FFH helper routines for RISC-V.
+ *
+ * Copyright (C) 2024 Ventana Micro Systems Inc.
+ */
+
+#include <acpi/cppc_acpi.h>
+#include <asm/csr.h>
+#include <asm/sbi.h>
+
+#define SBI_EXT_CPPC 0x43505043
+
+/* CPPC interfaces defined in SBI spec */
+#define SBI_CPPC_PROBE 0x0
+#define SBI_CPPC_READ 0x1
+#define SBI_CPPC_READ_HI 0x2
+#define SBI_CPPC_WRITE 0x3
+
+/* RISC-V FFH definitions from RISC-V FFH spec */
+#define FFH_CPPC_TYPE(r) (((r) & GENMASK_ULL(63, 60)) >> 60)
+#define FFH_CPPC_SBI_REG(r) ((r) & GENMASK(31, 0))
+#define FFH_CPPC_CSR_NUM(r) ((r) & GENMASK(11, 0))
+
+#define FFH_CPPC_SBI 0x1
+#define FFH_CPPC_CSR 0x2
+
+struct sbi_cppc_data {
+ u64 val;
+ u32 reg;
+ struct sbiret ret;
+};
+
+static bool cppc_ext_present;
+
+static int __init sbi_cppc_init(void)
+{
+ if (sbi_spec_version >= sbi_mk_version(2, 0) &&
+ sbi_probe_extension(SBI_EXT_CPPC) > 0) {
+ pr_info("SBI CPPC extension detected\n");
+ cppc_ext_present = true;
+ } else {
+ pr_info("SBI CPPC extension NOT detected!!\n");
+ cppc_ext_present = false;
+ }
+
+ return 0;
+}
+device_initcall(sbi_cppc_init);
+
+static void sbi_cppc_read(void *read_data)
+{
+ struct sbi_cppc_data *data = (struct sbi_cppc_data *)read_data;
+
+ data->ret = sbi_ecall(SBI_EXT_CPPC, SBI_CPPC_READ,
+ data->reg, 0, 0, 0, 0, 0);
+}
+
+static void sbi_cppc_write(void *write_data)
+{
+ struct sbi_cppc_data *data = (struct sbi_cppc_data *)write_data;
+
+ data->ret = sbi_ecall(SBI_EXT_CPPC, SBI_CPPC_WRITE,
+ data->reg, data->val, 0, 0, 0, 0);
+}
+
+static void cppc_ffh_csr_read(void *read_data)
+{
+ struct sbi_cppc_data *data = (struct sbi_cppc_data *)read_data;
+
+ switch (data->reg) {
+ /* Support only TIME CSR for now */
+ case CSR_TIME:
+ data->ret.value = csr_read(CSR_TIME);
+ data->ret.error = 0;
+ break;
+ default:
+ data->ret.error = -EINVAL;
+ break;
+ }
+}
+
+static void cppc_ffh_csr_write(void *write_data)
+{
+ struct sbi_cppc_data *data = (struct sbi_cppc_data *)write_data;
+
+ data->ret.error = -EINVAL;
+}
+
+/*
+ * Refer to drivers/acpi/cppc_acpi.c for the description of the functions
+ * below.
+ */
+bool cpc_ffh_supported(void)
+{
+ return true;
+}
+
+int cpc_read_ffh(int cpu, struct cpc_reg *reg, u64 *val)
+{
+ struct sbi_cppc_data data;
+
+ if (WARN_ON_ONCE(irqs_disabled()))
+ return -EPERM;
+
+ if (FFH_CPPC_TYPE(reg->address) == FFH_CPPC_SBI) {
+ if (!cppc_ext_present)
+ return -EINVAL;
+
+ data.reg = FFH_CPPC_SBI_REG(reg->address);
+
+ smp_call_function_single(cpu, sbi_cppc_read, &data, 1);
+
+ *val = data.ret.value;
+
+ return (data.ret.error) ? sbi_err_map_linux_errno(data.ret.error) : 0;
+ } else if (FFH_CPPC_TYPE(reg->address) == FFH_CPPC_CSR) {
+ data.reg = FFH_CPPC_CSR_NUM(reg->address);
+
+ smp_call_function_single(cpu, cppc_ffh_csr_read, &data, 1);
+
+ *val = data.ret.value;
+
+ return (data.ret.error) ? sbi_err_map_linux_errno(data.ret.error) : 0;
+ }
+
+ return -EINVAL;
+}
+
+int cpc_write_ffh(int cpu, struct cpc_reg *reg, u64 val)
+{
+ struct sbi_cppc_data data;
+
+ if (WARN_ON_ONCE(irqs_disabled()))
+ return -EPERM;
+
+ if (FFH_CPPC_TYPE(reg->address) == FFH_CPPC_SBI) {
+ if (!cppc_ext_present)
+ return -EINVAL;
+
+ data.reg = FFH_CPPC_SBI_REG(reg->address);
+ data.val = val;
+
+ smp_call_function_single(cpu, sbi_cppc_write, &data, 1);
+
+ return (data.ret.error) ? sbi_err_map_linux_errno(data.ret.error) : 0;
+ } else if (FFH_CPPC_TYPE(reg->address) == FFH_CPPC_CSR) {
+ data.reg = FFH_CPPC_CSR_NUM(reg->address);
+ data.val = val;
+
+ smp_call_function_single(cpu, cppc_ffh_csr_write, &data, 1);
+
+ return (data.ret.error) ? sbi_err_map_linux_errno(data.ret.error) : 0;
+ }
+
+ return -EINVAL;
+}