[PATCH RFC] platform: generic: How to add custom extensions for sbi_call?

[guoren at kernel.org]

From: Guo Ren <guoren at linux.alibaba.com>

Here is the sample of thead PMU sbi implementation, it could work
with linux perf record:

https://github.com/c-sky/csky-linux/blob/linux-5.10.4/drivers/perf/thead_c900_pmu.c

It support perf record with hardware event.

How to support this in platform/generic?

Thx

Signed-off-by: Guo Ren <guoren at linux.alibaba.com>
Cc: Anup Patel <anup.patel at wdc.com>
---
 platform/generic/platform.c | 159 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 159 insertions(+)

diff --git a/platform/generic/platform.c b/platform/generic/platform.c
index 7581556..52084dd 100644
--- a/platform/generic/platform.c
+++ b/platform/generic/platform.c
@@ -206,7 +206,166 @@ static void generic_system_reset(u32 reset_type, u32 reset_reason)
 	writew(0x5555, (void *)0x100000); // qemu poweroff
 }
 
+#include <sbi/sbi_trap.h>
+#define CSR_MCOUNTERWEN  0x7c9
+static void sbi_thead_pmu_init(void)
+{
+	unsigned long interrupts;
+
+	interrupts = csr_read(CSR_MIDELEG) | (1 << 17);
+	csr_write(CSR_MIDELEG, interrupts);
+
+	/* CSR_MCOUNTEREN has already been set in mstatus_init() */
+	csr_write(CSR_MCOUNTERWEN, 0xffffffff);
+	csr_write(CSR_MHPMEVENT3, 1);
+	csr_write(CSR_MHPMEVENT4, 2);
+	csr_write(CSR_MHPMEVENT5, 3);
+	csr_write(CSR_MHPMEVENT6, 4);
+	csr_write(CSR_MHPMEVENT7, 5);
+	csr_write(CSR_MHPMEVENT8, 6);
+	csr_write(CSR_MHPMEVENT9, 7);
+	csr_write(CSR_MHPMEVENT10, 8);
+	csr_write(CSR_MHPMEVENT11, 9);
+	csr_write(CSR_MHPMEVENT12, 10);
+	csr_write(CSR_MHPMEVENT13, 11);
+	csr_write(CSR_MHPMEVENT14, 12);
+	csr_write(CSR_MHPMEVENT15, 13);
+	csr_write(CSR_MHPMEVENT16, 14);
+	csr_write(CSR_MHPMEVENT17, 15);
+	csr_write(CSR_MHPMEVENT18, 16);
+	csr_write(CSR_MHPMEVENT19, 17);
+	csr_write(CSR_MHPMEVENT20, 18);
+	csr_write(CSR_MHPMEVENT21, 19);
+	csr_write(CSR_MHPMEVENT22, 20);
+	csr_write(CSR_MHPMEVENT23, 21);
+	csr_write(CSR_MHPMEVENT24, 22);
+	csr_write(CSR_MHPMEVENT25, 23);
+	csr_write(CSR_MHPMEVENT26, 24);
+	csr_write(CSR_MHPMEVENT27, 25);
+	csr_write(CSR_MHPMEVENT28, 26);
+}
+
+static void sbi_thead_pmu_map(unsigned long idx, unsigned long event_id)
+{
+	switch (idx) {
+	case 3:
+		csr_write(CSR_MHPMEVENT3, event_id);
+		break;
+	case 4:
+		csr_write(CSR_MHPMEVENT4, event_id);
+		break;
+	case 5:
+		csr_write(CSR_MHPMEVENT5, event_id);
+		break;
+	case 6:
+		csr_write(CSR_MHPMEVENT6, event_id);
+		break;
+	case 7:
+		csr_write(CSR_MHPMEVENT7, event_id);
+		break;
+	case 8:
+		csr_write(CSR_MHPMEVENT8, event_id);
+		break;
+	case 9:
+		csr_write(CSR_MHPMEVENT9, event_id);
+		break;
+	case 10:
+		csr_write(CSR_MHPMEVENT10, event_id);
+		break;
+	case 11:
+		csr_write(CSR_MHPMEVENT11, event_id);
+		break;
+	case 12:
+		csr_write(CSR_MHPMEVENT12, event_id);
+		break;
+	case 13:
+		csr_write(CSR_MHPMEVENT13, event_id);
+		break;
+	case 14:
+		csr_write(CSR_MHPMEVENT14, event_id);
+		break;
+	case 15:
+		csr_write(CSR_MHPMEVENT15, event_id);
+		break;
+	case 16:
+		csr_write(CSR_MHPMEVENT16, event_id);
+		break;
+	case 17:
+		csr_write(CSR_MHPMEVENT17, event_id);
+		break;
+	case 18:
+		csr_write(CSR_MHPMEVENT18, event_id);
+		break;
+	case 19:
+		csr_write(CSR_MHPMEVENT19, event_id);
+		break;
+	case 20:
+		csr_write(CSR_MHPMEVENT20, event_id);
+		break;
+	case 21:
+		csr_write(CSR_MHPMEVENT21, event_id);
+		break;
+	case 22:
+		csr_write(CSR_MHPMEVENT22, event_id);
+		break;
+	case 23:
+		csr_write(CSR_MHPMEVENT23, event_id);
+		break;
+	case 24:
+		csr_write(CSR_MHPMEVENT24, event_id);
+		break;
+	case 25:
+		csr_write(CSR_MHPMEVENT25, event_id);
+		break;
+	case 26:
+		csr_write(CSR_MHPMEVENT26, event_id);
+		break;
+	case 27:
+		csr_write(CSR_MHPMEVENT27, event_id);
+		break;
+	case 28:
+		csr_write(CSR_MHPMEVENT28, event_id);
+		break;
+	case 29:
+		csr_write(CSR_MHPMEVENT29, event_id);
+		break;
+	case 30:
+		csr_write(CSR_MHPMEVENT30, event_id);
+		break;
+	case 31:
+		csr_write(CSR_MHPMEVENT31, event_id);
+		break;
+	}
+}
+
+static void sbi_thead_pmu_set(unsigned long type, unsigned long idx, unsigned long event_id)
+{
+	switch (type) {
+	case 2:
+		sbi_thead_pmu_map(idx, event_id);
+		break;
+	default:
+		sbi_thead_pmu_init();
+		break;
+	}
+}
+
+static int thead_vendor_ext_provider(long extid, long funcid,
+	const struct sbi_trap_regs *regs, unsigned long *out_value,
+	struct sbi_trap_info *out_trap)
+{
+	switch (extid) {
+	case 0x09000001:
+		sbi_thead_pmu_set(regs->a0, regs->a1, regs->a2);
+		break;
+	default:
+		sbi_hart_hang();
+	}
+	return 0;
+}
+
 const struct sbi_platform_operations platform_ops = {
+	.vendor_ext_provider	= thead_vendor_ext_provider,
 	.early_init		= generic_early_init,
 	.final_init		= generic_final_init,
 	.early_exit		= generic_early_exit,
-- 
2.7.4