platform: generic: allwinner: add support for c9xx pmu

With the T-HEAD C9XX cores being designed before or during ratification
of the SSCOFPMF extension, they implement a PMU extension that behaves
very similar but not equal to it by providing overflow interrupts though
in a slightly different registers format.

The sun20i-d1 is using this core. So implement the necessary overrides
to allow its pmu to be used via the standard sbi-pmu extension.

For now it's also the only soc using this core, so keep the additional
code in the d1-space for now.

Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Guo Ren <guoren@kernel.org>
Reviewed-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>

2 files changed, 187 insertions, 0 deletions

diff --git a/platform/generic/allwinner/sun20i-d1.c b/platform/generic/allwinner/sun20i-d1.c
index 5b2656c..6a502e5 100644
--- a/platform/generic/allwinner/sun20i-d1.c
+++ b/platform/generic/allwinner/sun20i-d1.c
@@ -5,11 +5,13 @@
  */
 
 #include <platform_override.h>
+#include <thead_c9xx.h>
 #include <sbi/riscv_io.h>
 #include <sbi/sbi_bitops.h>
 #include <sbi/sbi_ecall_interface.h>
 #include <sbi/sbi_error.h>
 #include <sbi/sbi_hsm.h>
+#include <sbi/sbi_pmu.h>
 #include <sbi_utils/fdt/fdt_helper.h>
 #include <sbi_utils/irqchip/fdt_irqchip_plic.h>
 
@@ -199,6 +201,63 @@ static int sun20i_d1_final_init(bool cold_boot, const struct fdt_match *match)
 	return 0;
 }
 
+#include <sbi/sbi_console.h>
+
+static void thead_c9xx_pmu_ctr_enable_irq(uint32_t ctr_idx)
+{
+	unsigned long mip_val;
+
+	if (ctr_idx >= SBI_PMU_HW_CTR_MAX)
+		return;
+
+	mip_val = csr_read(CSR_MIP);
+	/**
+	 * Clear out the OF bit so that next interrupt can be enabled.
+	 * This should be done only when the corresponding overflow interrupt
+	 * bit is cleared. That indicates that software has already handled the
+	 * previous interrupts or the hardware yet to set an overflow interrupt.
+	 * Otherwise, there will be race conditions where we may clear the bit
+	 * the software is yet to handle the interrupt.
+	 */
+	if (!(mip_val & THEAD_C9XX_MIP_MOIP))
+		csr_clear(THEAD_C9XX_CSR_MCOUNTEROF, BIT(ctr_idx));
+
+	/**
+	 * SSCOFPMF uses the OF bit for enabling/disabling the interrupt,
+	 * while the C9XX has designated enable bits.
+	 * So enable per-counter interrupt on C9xx here.
+	 */
+	csr_set(THEAD_C9XX_CSR_MCOUNTERINTEN, BIT(ctr_idx));
+}
+
+static void thead_c9xx_pmu_ctr_disable_irq(uint32_t ctr_idx)
+{
+	csr_clear(THEAD_C9XX_CSR_MCOUNTERINTEN, BIT(ctr_idx));
+}
+
+static int thead_c9xx_pmu_irq_bit(void)
+{
+	return THEAD_C9XX_MIP_MOIP;
+}
+
+const struct sbi_pmu_device thead_c9xx_pmu_device = {
+	.hw_counter_enable_irq = thead_c9xx_pmu_ctr_enable_irq,
+	.hw_counter_disable_irq = thead_c9xx_pmu_ctr_disable_irq,
+	.hw_counter_irq_bit = thead_c9xx_pmu_irq_bit,
+};
+
+static int sun20i_d1_extensions_init(const struct fdt_match *match,
+				     struct sbi_hart_features *hfeatures)
+{
+	sbi_pmu_set_device(&thead_c9xx_pmu_device);
+
+	/* auto-detection doesn't work on t-head c9xx cores */
+	hfeatures->mhpm_count = 29;
+	hfeatures->mhpm_bits = 64;
+
+	return 0;
+}
+
 static const struct fdt_match sun20i_d1_match[] = {
 	{ .compatible = "allwinner,sun20i-d1" },
 	{ },
@@ -207,4 +266,5 @@ static const struct fdt_match sun20i_d1_match[] = {
 const struct platform_override sun20i_d1 = {
 	.match_table	= sun20i_d1_match,
 	.final_init	= sun20i_d1_final_init,
+	.extensions_init = sun20i_d1_extensions_init,
 };
diff --git a/platform/generic/include/thead_c9xx.h b/platform/generic/include/thead_c9xx.h
new file mode 100644
index 0000000..bab0408
--- /dev/null
+++ b/platform/generic/include/thead_c9xx.h
@@ -0,0 +1,127 @@
+#ifndef __RISCV_THEAD_C9XX_H____
+#define __RISCV_THEAD_C9XX_H____
+
+/* T-HEAD C9xx M mode CSR.  */
+#define THEAD_C9XX_CSR_MXSTATUS		0x7c0
+#define THEAD_C9XX_CSR_MHCR		0x7c1
+#define THEAD_C9XX_CSR_MCOR		0x7c2
+#define THEAD_C9XX_CSR_MCCR2		0x7c3
+#define THEAD_C9XX_CSR_MCER2		0x7c4
+#define THEAD_C9XX_CSR_MHINT		0x7c5
+#define THEAD_C9XX_CSR_MRMR		0x7c6
+#define THEAD_C9XX_CSR_MRVBR		0x7c7
+#define THEAD_C9XX_CSR_MCER		0x7c8
+#define THEAD_C9XX_CSR_MCOUNTERWEN	0x7c9
+#define THEAD_C9XX_CSR_MCOUNTERINTEN	0x7ca
+#define THEAD_C9XX_CSR_MCOUNTEROF	0x7cb
+#define THEAD_C9XX_CSR_MHINT2		0x7cc
+#define THEAD_C9XX_CSR_MHINT3		0x7cd
+#define THEAD_C9XX_CSR_MRADDR		0x7e0
+#define THEAD_C9XX_CSR_MEXSTATUS	0x7e1
+#define THEAD_C9XX_CSR_MNMICAUSE	0x7e2
+#define THEAD_C9XX_CSR_MNMIPC		0x7e3
+#define THEAD_C9XX_CSR_MHPMCR		0x7f0
+#define THEAD_C9XX_CSR_MHPMSR		0x7f1
+#define THEAD_C9XX_CSR_MHPMER		0x7f2
+#define THEAD_C9XX_CSR_MSMPR		0x7f3
+#define THEAD_C9XX_CSR_MTEECFG		0x7f4
+#define THEAD_C9XX_CSR_MZONEID		0x7f5
+#define THEAD_C9XX_CSR_ML2CPID		0x7f6
+#define THEAD_C9XX_CSR_ML2WP		0x7f7
+#define THEAD_C9XX_CSR_MDTCMCR		0x7f8
+#define THEAD_C9XX_CSR_USP		0x7d1
+#define THEAD_C9XX_CSR_MCINS		0x7d2
+#define THEAD_C9XX_CSR_MCINDEX		0x7d3
+#define THEAD_C9XX_CSR_MCDATA0		0x7d4
+#define THEAD_C9XX_CSR_MCDATA1		0x7d5
+#define THEAD_C9XX_CSR_MEICR		0x7d6
+#define THEAD_C9XX_CSR_MEICR2		0x7d7
+#define THEAD_C9XX_CSR_MBEADDR		0x7d8
+#define THEAD_C9XX_CSR_MCPUID		0xfc0
+#define THEAD_C9XX_CSR_MAPBADDR		0xfc1
+#define THEAD_C9XX_CSR_MWMSR		0xfc2
+#define THEAD_C9XX_CSR_MHALTCAUSE	0xfe0
+#define THEAD_C9XX_CSR_MDBGINFO		0xfe1
+#define THEAD_C9XX_CSR_MPCFIFO		0xfe2
+
+/* T-HEAD C9xx S mode CSR.  */
+#define THEAD_C9XX_CSR_SXSTATUS		0x5c0
+#define THEAD_C9XX_CSR_SHCR		0x5c1
+#define THEAD_C9XX_CSR_SCER2		0x5c2
+#define THEAD_C9XX_CSR_SCER		0x5c3
+#define THEAD_C9XX_CSR_SCOUNTERINTEN	0x5c4
+#define THEAD_C9XX_CSR_SCOUNTEROF	0x5c5
+#define THEAD_C9XX_CSR_SHINT		0x5c6
+#define THEAD_C9XX_CSR_SHINT2		0x5c7
+#define THEAD_C9XX_CSR_SHPMINHIBIT	0x5c8
+#define THEAD_C9XX_CSR_SHPMCR		0x5c9
+#define THEAD_C9XX_CSR_SHPMSR		0x5ca
+#define THEAD_C9XX_CSR_SHPMER		0x5cb
+#define THEAD_C9XX_CSR_SL2CPID		0x5cc
+#define THEAD_C9XX_CSR_SL2WP		0x5cd
+#define THEAD_C9XX_CSR_SBEADDR		0x5d0
+#define THEAD_C9XX_CSR_SCYCLE		0x5e0
+#define THEAD_C9XX_CSR_SHPMCOUNTER1	0x5e1
+#define THEAD_C9XX_CSR_SHPMCOUNTER2	0x5e2
+#define THEAD_C9XX_CSR_SHPMCOUNTER3	0x5e3
+#define THEAD_C9XX_CSR_SHPMCOUNTER4	0x5e4
+#define THEAD_C9XX_CSR_SHPMCOUNTER5	0x5e5
+#define THEAD_C9XX_CSR_SHPMCOUNTER6	0x5e6
+#define THEAD_C9XX_CSR_SHPMCOUNTER7	0x5e7
+#define THEAD_C9XX_CSR_SHPMCOUNTER8	0x5e8
+#define THEAD_C9XX_CSR_SHPMCOUNTER9	0x5e9
+#define THEAD_C9XX_CSR_SHPMCOUNTER10	0x5ea
+#define THEAD_C9XX_CSR_SHPMCOUNTER11	0x5eb
+#define THEAD_C9XX_CSR_SHPMCOUNTER12	0x5ec
+#define THEAD_C9XX_CSR_SHPMCOUNTER13	0x5ed
+#define THEAD_C9XX_CSR_SHPMCOUNTER14	0x5ee
+#define THEAD_C9XX_CSR_SHPMCOUNTER15	0x5ef
+#define THEAD_C9XX_CSR_SHPMCOUNTER16	0x5f0
+#define THEAD_C9XX_CSR_SHPMCOUNTER17	0x5f1
+#define THEAD_C9XX_CSR_SHPMCOUNTER18	0x5f2
+#define THEAD_C9XX_CSR_SHPMCOUNTER19	0x5f3
+#define THEAD_C9XX_CSR_SHPMCOUNTER20	0x5f4
+#define THEAD_C9XX_CSR_SHPMCOUNTER21	0x5f5
+#define THEAD_C9XX_CSR_SHPMCOUNTER22	0x5f6
+#define THEAD_C9XX_CSR_SHPMCOUNTER23	0x5f7
+#define THEAD_C9XX_CSR_SHPMCOUNTER24	0x5f8
+#define THEAD_C9XX_CSR_SHPMCOUNTER25	0x5f9
+#define THEAD_C9XX_CSR_SHPMCOUNTER26	0x5fa
+#define THEAD_C9XX_CSR_SHPMCOUNTER27	0x5fb
+#define THEAD_C9XX_CSR_SHPMCOUNTER28	0x5fc
+#define THEAD_C9XX_CSR_SHPMCOUNTER29	0x5fd
+#define THEAD_C9XX_CSR_SHPMCOUNTER30	0x5fe
+#define THEAD_C9XX_CSR_SHPMCOUNTER31	0x5ff
+
+/* T-HEAD C9xx U mode CSR.  */
+#define THEAD_C9XX_CSR_FXCR		0x800
+
+/* T-HEAD C9xx MMU extentions.  */
+#define THEAD_C9XX_CSR_SMIR		0x9c0
+#define THEAD_C9XX_CSR_SMEL		0x9c1
+#define THEAD_C9XX_CSR_SMEH		0x9c2
+#define THEAD_C9XX_CSR_SMCIR		0x9c3
+
+/* T-HEAD C9xx Security CSR(May be droped).  */
+#define THEAD_C9XX_CSR_MEBR		0xbe0
+#define THEAD_C9XX_CSR_NT_MSTATUS	0xbe1
+#define THEAD_C9XX_CSR_NT_MIE		0xbe2
+#define THEAD_C9XX_CSR_NT_MTVEC		0xbe3
+#define THEAD_C9XX_CSR_NT_MTVT		0xbe4
+#define THEAD_C9XX_CSR_NT_MEPC		0xbe5
+#define THEAD_C9XX_CSR_NT_MCAUSE	0xbe6
+#define THEAD_C9XX_CSR_NT_MIP		0xbe7
+#define THEAD_C9XX_CSR_NT_MINTSTATE	0xbe8
+#define THEAD_C9XX_CSR_NT_MXSTATUS	0xbe9
+#define THEAD_C9XX_CSR_NT_MEBR		0xbea
+#define THEAD_C9XX_CSR_NT_MSP		0xbeb
+#define THEAD_C9XX_CSR_T_USP		0xbec
+#define THEAD_C9XX_CSR_T_MDCR		0xbed
+#define THEAD_C9XX_CSR_T_MPCR		0xbee
+#define THEAD_C9XX_CSR_PMPTEECFG	0xbef
+
+/* T-HEAD C9xx MIP CSR extension */
+#define THEAD_C9XX_IRQ_PMU_OVF		17
+#define THEAD_C9XX_MIP_MOIP		(_UL(1) << THEAD_C9XX_IRQ_PMU_OVF)
+
+#endif