processor.h

/* SPDX-License-Identifier: GPL-2.0-only */

#ifndef SELFTEST_KVM_PROCESSOR_H
#define SELFTEST_KVM_PROCESSOR_H

#ifndef __ASSEMBLER__
#include "ucall_common.h"

#else
/* general registers */
#define zero				$r0
#define ra				$r1
#define tp				$r2
#define sp				$r3
#define a0				$r4
#define a1				$r5
#define a2				$r6
#define a3				$r7
#define a4				$r8
#define a5				$r9
#define a6				$r10
#define a7				$r11
#define t0				$r12
#define t1				$r13
#define t2				$r14
#define t3				$r15
#define t4				$r16
#define t5				$r17
#define t6				$r18
#define t7				$r19
#define t8				$r20
#define u0				$r21
#define fp				$r22
#define s0				$r23
#define s1				$r24
#define s2				$r25
#define s3				$r26
#define s4				$r27
#define s5				$r28
#define s6				$r29
#define s7				$r30
#define s8				$r31
#endif

/*
 * LoongArch page table entry definition
 * Original header file arch/loongarch/include/asm/loongarch.h
 */
#define _PAGE_VALID_SHIFT		0
#define _PAGE_DIRTY_SHIFT		1
#define _PAGE_PLV_SHIFT			2  /* 2~3, two bits */
#define  PLV_KERN			0
#define  PLV_USER			3
#define  PLV_MASK			0x3
#define _CACHE_SHIFT			4  /* 4~5, two bits */
#define _PAGE_PRESENT_SHIFT		7
#define _PAGE_WRITE_SHIFT		8

#define _PAGE_VALID			BIT_ULL(_PAGE_VALID_SHIFT)
#define _PAGE_PRESENT			BIT_ULL(_PAGE_PRESENT_SHIFT)
#define _PAGE_WRITE			BIT_ULL(_PAGE_WRITE_SHIFT)
#define _PAGE_DIRTY			BIT_ULL(_PAGE_DIRTY_SHIFT)
#define _PAGE_USER			(PLV_USER << _PAGE_PLV_SHIFT)
#define   __READABLE			(_PAGE_VALID)
#define   __WRITEABLE			(_PAGE_DIRTY | _PAGE_WRITE)
/* Coherent Cached */
#define _CACHE_CC			BIT_ULL(_CACHE_SHIFT)
#define PS_4K				0x0000000c
#define PS_16K				0x0000000e
#define PS_64K				0x00000010
#define PS_DEFAULT_SIZE			PS_16K

/* LoongArch Basic CSR registers */
#define LOONGARCH_CSR_CRMD		0x0 /* Current mode info */
#define  CSR_CRMD_PG_SHIFT		4
#define  CSR_CRMD_PG			BIT_ULL(CSR_CRMD_PG_SHIFT)
#define  CSR_CRMD_IE_SHIFT		2
#define  CSR_CRMD_IE			BIT_ULL(CSR_CRMD_IE_SHIFT)
#define  CSR_CRMD_PLV_SHIFT		0
#define  CSR_CRMD_PLV_WIDTH		2
#define  CSR_CRMD_PLV			(0x3UL << CSR_CRMD_PLV_SHIFT)
#define  PLV_MASK			0x3
#define LOONGARCH_CSR_PRMD		0x1
#define LOONGARCH_CSR_EUEN		0x2
#define LOONGARCH_CSR_ECFG		0x4
#define  ECFGB_TIMER			11
#define  ECFGF_TIMER			(BIT_ULL(ECFGB_TIMER))
#define LOONGARCH_CSR_ESTAT		0x5  /* Exception status */
#define  CSR_ESTAT_EXC_SHIFT		16
#define  CSR_ESTAT_EXC_WIDTH		6
#define  CSR_ESTAT_EXC			(0x3f << CSR_ESTAT_EXC_SHIFT)
#define    EXCCODE_INT			0    /* Interrupt */
#define      INT_TI			11   /* Timer interrupt*/
#define LOONGARCH_CSR_ERA		0x6  /* ERA */
#define LOONGARCH_CSR_BADV		0x7  /* Bad virtual address */
#define LOONGARCH_CSR_EENTRY		0xc
#define LOONGARCH_CSR_TLBIDX		0x10 /* TLB Index, EHINV, PageSize */
#define  CSR_TLBIDX_PS_SHIFT		24
#define  CSR_TLBIDX_PS_WIDTH		6
#define  CSR_TLBIDX_PS			(0x3fUL << CSR_TLBIDX_PS_SHIFT)
#define  CSR_TLBIDX_SIZEM		0x3f000000
#define  CSR_TLBIDX_SIZE		CSR_TLBIDX_PS_SHIFT
#define LOONGARCH_CSR_ASID		0x18 /* ASID */
#define LOONGARCH_CSR_PGDL		0x19
#define LOONGARCH_CSR_PGDH		0x1a
/* Page table base */
#define LOONGARCH_CSR_PGD		0x1b
#define LOONGARCH_CSR_PWCTL0		0x1c
#define LOONGARCH_CSR_PWCTL1		0x1d
#define LOONGARCH_CSR_STLBPGSIZE	0x1e
#define LOONGARCH_CSR_CPUID		0x20
#define LOONGARCH_CSR_KS0		0x30
#define LOONGARCH_CSR_KS1		0x31
#define LOONGARCH_CSR_TMID		0x40
#define LOONGARCH_CSR_TCFG		0x41
#define  CSR_TCFG_VAL			(BIT_ULL(48) - BIT_ULL(2))
#define  CSR_TCFG_PERIOD_SHIFT		1
#define  CSR_TCFG_PERIOD		(0x1UL << CSR_TCFG_PERIOD_SHIFT)
#define  CSR_TCFG_EN			(0x1UL)
#define LOONGARCH_CSR_TVAL		0x42
#define LOONGARCH_CSR_TINTCLR		0x44 /* Timer interrupt clear */
#define  CSR_TINTCLR_TI_SHIFT		0
#define  CSR_TINTCLR_TI			(1 << CSR_TINTCLR_TI_SHIFT)
/* TLB refill exception entry */
#define LOONGARCH_CSR_TLBRENTRY		0x88
#define LOONGARCH_CSR_TLBRSAVE		0x8b
#define LOONGARCH_CSR_TLBREHI		0x8e
#define  CSR_TLBREHI_PS_SHIFT		0
#define  CSR_TLBREHI_PS			(0x3fUL << CSR_TLBREHI_PS_SHIFT)

#define csr_read(csr)				\
({						\
	register unsigned long __v;		\
	__asm__ __volatile__(			\
		"csrrd %[val], %[reg]\n\t"	\
		: [val] "=r" (__v)		\
		: [reg] "i" (csr)		\
		: "memory");			\
	__v;					\
})

#define csr_write(v, csr)			\
({						\
	register unsigned long __v = v;		\
	__asm__ __volatile__ (			\
		"csrwr %[val], %[reg]\n\t"	\
		: [val] "+r" (__v)		\
		: [reg] "i" (csr)		\
		: "memory");			\
	__v;					\
})

#define EXREGS_GPRS			(32)

#ifndef __ASSEMBLER__
void handle_tlb_refill(void);
void handle_exception(void);

struct ex_regs {
	unsigned long regs[EXREGS_GPRS];
	unsigned long pc;
	unsigned long estat;
	unsigned long badv;
	unsigned long prmd;
};

#define PC_OFFSET_EXREGS		offsetof(struct ex_regs, pc)
#define ESTAT_OFFSET_EXREGS		offsetof(struct ex_regs, estat)
#define BADV_OFFSET_EXREGS		offsetof(struct ex_regs, badv)
#define PRMD_OFFSET_EXREGS		offsetof(struct ex_regs, prmd)
#define EXREGS_SIZE			sizeof(struct ex_regs)

#define VECTOR_NUM			64

typedef void(*handler_fn)(struct ex_regs *);

struct handlers {
	handler_fn exception_handlers[VECTOR_NUM];
};

void vm_init_descriptor_tables(struct kvm_vm *vm);
void vm_install_exception_handler(struct kvm_vm *vm, int vector, handler_fn handler);

static inline void cpu_relax(void)
{
	asm volatile("nop" ::: "memory");
}

static inline void local_irq_enable(void)
{
	unsigned int flags = CSR_CRMD_IE;
	register unsigned int mask asm("$t0") = CSR_CRMD_IE;

	__asm__ __volatile__(
		"csrxchg %[val], %[mask], %[reg]\n\t"
		: [val] "+r" (flags)
		: [mask] "r" (mask), [reg] "i" (LOONGARCH_CSR_CRMD)
		: "memory");
}

static inline void local_irq_disable(void)
{
	unsigned int flags = 0;
	register unsigned int mask asm("$t0") = CSR_CRMD_IE;

	__asm__ __volatile__(
		"csrxchg %[val], %[mask], %[reg]\n\t"
		: [val] "+r" (flags)
		: [mask] "r" (mask), [reg] "i" (LOONGARCH_CSR_CRMD)
		: "memory");
}
#else
#define PC_OFFSET_EXREGS		((EXREGS_GPRS + 0) * 8)
#define ESTAT_OFFSET_EXREGS		((EXREGS_GPRS + 1) * 8)
#define BADV_OFFSET_EXREGS		((EXREGS_GPRS + 2) * 8)
#define PRMD_OFFSET_EXREGS		((EXREGS_GPRS + 3) * 8)
#define EXREGS_SIZE			((EXREGS_GPRS + 4) * 8)
#endif

#endif /* SELFTEST_KVM_PROCESSOR_H */