RISC-V: Add sscofpmf extension support

The sscofpmf extension allows counter overflow and filtering for
programmable counters. Enable the perf driver to handle the overflow
interrupt. The overflow interrupt is a hart local interrupt.
Thus, per cpu overflow interrupts are setup as a child under the root
INTC irq domain.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

4 files changed, 11 insertions, 1 deletions

diff --git a/arch/riscv/include/asm/csr.h b/arch/riscv/include/asm/csr.h
index ce493df11177..8b2e48077731 100644
--- a/arch/riscv/include/asm/csr.h
+++ b/arch/riscv/include/asm/csr.h
@@ -65,6 +65,7 @@
 #define IRQ_S_EXT		9
 #define IRQ_VS_EXT		10
 #define IRQ_M_EXT		11
+#define IRQ_PMU_OVF		13
 
 /* Exception causes */
 #define EXC_INST_MISALIGNED	0
@@ -212,6 +213,8 @@
 #define CSR_HPMCOUNTER30H	0xc9e
 #define CSR_HPMCOUNTER31H	0xc9f
 
+#define CSR_SSCOUNTOVF		0xda0
+
 #define CSR_SSTATUS		0x100
 #define CSR_SIE			0x104
 #define CSR_STVEC		0x105
@@ -298,7 +301,10 @@
 # define RV_IRQ_SOFT		IRQ_S_SOFT
 # define RV_IRQ_TIMER	IRQ_S_TIMER
 # define RV_IRQ_EXT		IRQ_S_EXT
-#endif /* CONFIG_RISCV_M_MODE */
+# define RV_IRQ_PMU	IRQ_PMU_OVF
+# define SIP_LCOFIP     (_AC(0x1, UL) << IRQ_PMU_OVF)
+
+#endif /* !CONFIG_RISCV_M_MODE */
 
 /* IE/IP (Supervisor/Machine Interrupt Enable/Pending) flags */
 #define IE_SIE		(_AC(0x1, UL) << RV_IRQ_SOFT)
diff --git a/arch/riscv/include/asm/hwcap.h b/arch/riscv/include/asm/hwcap.h
index 691fc9c8099b..0734e42f74f2 100644
--- a/arch/riscv/include/asm/hwcap.h
+++ b/arch/riscv/include/asm/hwcap.h
@@ -51,6 +51,7 @@ extern unsigned long elf_hwcap;
  * available logical extension id.
  */
 enum riscv_isa_ext_id {
+	RISCV_ISA_EXT_SSCOFPMF = RISCV_ISA_EXT_BASE,
 	RISCV_ISA_EXT_ID_MAX = RISCV_ISA_EXT_MAX,
 };
 
diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c
index fc115e307ef5..c11cb576394d 100644
--- a/arch/riscv/kernel/cpu.c
+++ b/arch/riscv/kernel/cpu.c
@@ -87,6 +87,7 @@ int riscv_of_parent_hartid(struct device_node *node)
  *    extensions by an underscore.
  */
 static struct riscv_isa_ext_data isa_ext_arr[] = {
+	__RISCV_ISA_EXT_DATA(sscofpmf, RISCV_ISA_EXT_SSCOFPMF),
 	__RISCV_ISA_EXT_DATA("", RISCV_ISA_EXT_MAX),
 };
 
diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
index a43c08af5f4b..1b2d42d7f589 100644
--- a/arch/riscv/kernel/cpufeature.c
+++ b/arch/riscv/kernel/cpufeature.c
@@ -190,6 +190,8 @@ void __init riscv_fill_hwcap(void)
 			if (!ext_long) {
 				this_hwcap |= isa2hwcap[(unsigned char)(*ext)];
 				set_bit(*ext - 'a', this_isa);
+			} else {
+				SET_ISA_EXT_MAP("sscofpmf", RISCV_ISA_EXT_SSCOFPMF);
 			}
 #undef SET_ISA_EXT_MAP
 		}