[RFC patch 2/4] riscv: Get CPU manufacturer information

[Vincent Chen]

Issue 3 SBI calls to get the vendor ID, architecture ID and implementation
ID early in boot so we only need to take the SBI call overhead once.

Signed-off-by: Vincent Chen <vincent.chen at sifive.com>
---
 arch/riscv/include/asm/csr.h       |  3 +++
 arch/riscv/include/asm/hwcap.h     |  6 ++++++
 arch/riscv/include/asm/processor.h |  2 ++
 arch/riscv/include/asm/soc.h       |  1 +
 arch/riscv/kernel/cpufeature.c     | 17 +++++++++++++++++
 arch/riscv/kernel/setup.c          |  2 ++
 arch/riscv/kernel/soc.c            |  1 +
 7 files changed, 32 insertions(+)

diff --git a/arch/riscv/include/asm/csr.h b/arch/riscv/include/asm/csr.h
index caadfc1d7487..87ac65696871 100644
--- a/arch/riscv/include/asm/csr.h
+++ b/arch/riscv/include/asm/csr.h
@@ -115,6 +115,9 @@
 #define CSR_MIP			0x344
 #define CSR_PMPCFG0		0x3a0
 #define CSR_PMPADDR0		0x3b0
+#define CSR_MVENDORID		0xf11
+#define CSR_MARCHID		0xf12
+#define CSR_MIMPID		0xf13
 #define CSR_MHARTID		0xf14
 
 #ifdef CONFIG_RISCV_M_MODE
diff --git a/arch/riscv/include/asm/hwcap.h b/arch/riscv/include/asm/hwcap.h
index 5ce50468aff1..b7409487c9d2 100644
--- a/arch/riscv/include/asm/hwcap.h
+++ b/arch/riscv/include/asm/hwcap.h
@@ -44,6 +44,12 @@ bool __riscv_isa_extension_available(const unsigned long *isa_bitmap, int bit);
 #define riscv_isa_extension_available(isa_bitmap, ext)	\
 	__riscv_isa_extension_available(isa_bitmap, RISCV_ISA_EXT_##ext)
 
+struct cpu_manufacturer_info_t {
+	unsigned long vendor_id;
+	unsigned long arch_id;
+	unsigned long imp_id;
+};
+
 #endif
 
 #endif /* _ASM_RISCV_HWCAP_H */
diff --git a/arch/riscv/include/asm/processor.h b/arch/riscv/include/asm/processor.h
index 3a240037bde2..4e11a9621d14 100644
--- a/arch/riscv/include/asm/processor.h
+++ b/arch/riscv/include/asm/processor.h
@@ -72,6 +72,8 @@ int riscv_of_parent_hartid(struct device_node *node);
 
 extern void riscv_fill_hwcap(void);
 
+void riscv_fill_cpu_manufacturer_info(void);
+
 #endif /* __ASSEMBLY__ */
 
 #endif /* _ASM_RISCV_PROCESSOR_H */
diff --git a/arch/riscv/include/asm/soc.h b/arch/riscv/include/asm/soc.h
index f494066051a2..03dee6db404c 100644
--- a/arch/riscv/include/asm/soc.h
+++ b/arch/riscv/include/asm/soc.h
@@ -10,6 +10,7 @@
 #include <linux/of.h>
 #include <linux/linkage.h>
 #include <linux/types.h>
+#include <asm/hwcap.h>
 
 #define SOC_EARLY_INIT_DECLARE(name, compat, fn)			\
 	static const struct of_device_id __soc_early_init__##name	\
diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
index ac202f44a670..389162ee19ea 100644
--- a/arch/riscv/kernel/cpufeature.c
+++ b/arch/riscv/kernel/cpufeature.c
@@ -12,6 +12,8 @@
 #include <asm/hwcap.h>
 #include <asm/smp.h>
 #include <asm/switch_to.h>
+#include <asm/sbi.h>
+#include <asm/csr.h>
 
 unsigned long elf_hwcap __read_mostly;
 
@@ -22,6 +24,8 @@ static DECLARE_BITMAP(riscv_isa, RISCV_ISA_EXT_MAX) __read_mostly;
 bool has_fpu __read_mostly;
 #endif
 
+struct cpu_manufacturer_info_t cpu_mfr_info;
+
 /**
  * riscv_isa_extension_base() - Get base extension word
  *
@@ -149,3 +153,16 @@ void riscv_fill_hwcap(void)
 		has_fpu = true;
 #endif
 }
+
+void riscv_fill_cpu_manufacturer_info(void)
+{
+#ifndef CONFIG_RISCV_M_MODE
+	cpu_mfr_info.vendor_id = sbi_get_vendorid();
+	cpu_mfr_info.arch_id = sbi_get_archid();
+	cpu_mfr_info.imp_id = sbi_get_impid();
+#else
+	cpu_mfr_info.vendor_id = csr_read(CSR_MVENDORID);
+	cpu_mfr_info.arch_id = csr_read(CSR_MARCHID);
+	cpu_mfr_info.imp_id = csr_read(CSR_MIMPID);
+#endif
+}
diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c
index e85bacff1b50..03621ce9092c 100644
--- a/arch/riscv/kernel/setup.c
+++ b/arch/riscv/kernel/setup.c
@@ -278,6 +278,8 @@ void __init setup_arch(char **cmdline_p)
 #endif
 
 	riscv_fill_hwcap();
+
+	riscv_fill_cpu_manufacturer_info();
 }
 
 static int __init topology_init(void)
diff --git a/arch/riscv/kernel/soc.c b/arch/riscv/kernel/soc.c
index a0516172a33c..58f6fd91743a 100644
--- a/arch/riscv/kernel/soc.c
+++ b/arch/riscv/kernel/soc.c
@@ -6,6 +6,7 @@
 #include <linux/libfdt.h>
 #include <linux/pgtable.h>
 #include <asm/soc.h>
+#include <asm/hwcap.h>
 
 /*
  * This is called extremly early, before parse_dtb(), to allow initializing
-- 
2.7.4