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

#ifndef _PKEYS_X86_H
#define _PKEYS_X86_H

#ifdef __i386__

#define REG_IP_IDX              REG_EIP
#define si_pkey_offset          0x14

#else

#define REG_IP_IDX              REG_RIP
#define si_pkey_offset          0x20

#endif

#define MCONTEXT_IP(mc)         mc.gregs[REG_IP_IDX]
#define MCONTEXT_TRAPNO(mc)     mc.gregs[REG_TRAPNO]
#define MCONTEXT_FPREGS

#ifndef PKEY_DISABLE_ACCESS
# define PKEY_DISABLE_ACCESS    0x1
#endif

#ifndef PKEY_DISABLE_WRITE
# define PKEY_DISABLE_WRITE     0x2
#endif

#define NR_PKEYS                16
#define NR_RESERVED_PKEYS       2 /* pkey-0 and exec-only-pkey */
#define PKEY_BITS_PER_PKEY      2
#define HPAGE_SIZE              (1UL<<21)
#define PAGE_SIZE               4096
#define MB                      (1<<20)

#define PKEY_REG_ALLOW_NONE     0x55555555

static inline void __page_o_noops(void)
{
        /* 8-bytes of instruction * 512 bytes = 1 page */
        asm(".rept 512 ; nopl 0x7eeeeeee(%eax) ; .endr");
}

static inline u64 __read_pkey_reg(void)
{
        unsigned int eax, edx;
        unsigned int ecx = 0;
        unsigned pkey_reg;

        asm volatile(".byte 0x0f,0x01,0xee\n\t"
                     : "=a" (eax), "=d" (edx)
                     : "c" (ecx));
        pkey_reg = eax;
        return pkey_reg;
}

static inline void __write_pkey_reg(u64 pkey_reg)
{
        unsigned int eax = pkey_reg;
        unsigned int ecx = 0;
        unsigned int edx = 0;

        dprintf4("%s() changing %016llx to %016llx\n", __func__,
                        __read_pkey_reg(), pkey_reg);
        asm volatile(".byte 0x0f,0x01,0xef\n\t"
                     : : "a" (eax), "c" (ecx), "d" (edx));
        assert(pkey_reg == __read_pkey_reg());
}

/* Intel-defined CPU features, CPUID level 0x00000007:0 (ecx) */
#define X86_FEATURE_PKU        (1<<3) /* Protection Keys for Userspace */
#define X86_FEATURE_OSPKE      (1<<4) /* OS Protection Keys Enable */

static inline int cpu_has_pkeys(void)
{
        unsigned int eax;
        unsigned int ebx;
        unsigned int ecx;
        unsigned int edx;

        __cpuid_count(0x7, 0x0, eax, ebx, ecx, edx);

        if (!(ecx & X86_FEATURE_PKU)) {
                dprintf2("cpu does not have PKU\n");
                return 0;
        }
        if (!(ecx & X86_FEATURE_OSPKE)) {
                dprintf2("cpu does not have OSPKE\n");
                return 0;
        }
        return 1;
}

static inline int cpu_max_xsave_size(void)
{
        unsigned long XSTATE_CPUID = 0xd;
        unsigned int eax;
        unsigned int ebx;
        unsigned int ecx;
        unsigned int edx;

        __cpuid_count(XSTATE_CPUID, 0, eax, ebx, ecx, edx);
        return ecx;
}

static inline u32 pkey_bit_position(int pkey)
{
        return pkey * PKEY_BITS_PER_PKEY;
}

#define XSTATE_PKEY_BIT (9)
#define XSTATE_PKEY     0x200
#define XSTATE_BV_OFFSET        512

static inline int pkey_reg_xstate_offset(void)
{
        unsigned int eax;
        unsigned int ebx;
        unsigned int ecx;
        unsigned int edx;
        int xstate_offset;
        int xstate_size = 0;
        unsigned long XSTATE_CPUID = 0xd;
        int leaf;

        /* assume that XSTATE_PKEY is set in XCR0 */
        leaf = XSTATE_PKEY_BIT;
        {
                __cpuid_count(XSTATE_CPUID, leaf, eax, ebx, ecx, edx);

                if (leaf == XSTATE_PKEY_BIT) {
                        xstate_offset = ebx;
                        xstate_size = eax;
                }
        }

        if (xstate_size == 0) {
                printf("could not find size/offset of PKEY in xsave state\n");
                return 0;
        }

        return xstate_offset;
}

static inline int get_arch_reserved_keys(void)
{
        return NR_RESERVED_PKEYS;
}

static inline void expect_fault_on_read_execonly_key(void *p1, int pkey)
{
        int ptr_contents;

        ptr_contents = read_ptr(p1);
        dprintf2("ptr (%p) contents@%d: %x\n", p1, __LINE__, ptr_contents);
        expected_pkey_fault(pkey);
}

static inline void *malloc_pkey_with_mprotect_subpage(long size, int prot, u16 pkey)
{
        return PTR_ERR_ENOTSUP;
}

#endif /* _PKEYS_X86_H */