trng.c File Reference

#include <linux/arm-smccc.h>
#include <linux/kvm_host.h>
#include <asm/kvm_emulate.h>
#include <kvm/arm_hypercalls.h>

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Macros
#define	ARM_SMCCC_TRNG_VERSION_1_0   0x10000UL
#define	TRNG_SUCCESS   0UL
#define	TRNG_NOT_SUPPORTED   ((unsigned long)-1)
#define	TRNG_INVALID_PARAMETER   ((unsigned long)-2)
#define	TRNG_NO_ENTROPY   ((unsigned long)-3)
#define	TRNG_MAX_BITS64   192

Functions
static const uuid_t arm_smc_trng_uuid	__aligned (4)
static int	kvm_trng_do_rnd (struct kvm_vcpu *vcpu, int size)
int	kvm_trng_call (struct kvm_vcpu *vcpu)

Macro Definition Documentation

ARM_SMCCC_TRNG_VERSION_1_0

#define ARM_SMCCC_TRNG_VERSION_1_0   0x10000UL

Definition at line 11 of file trng.c.

TRNG_INVALID_PARAMETER

#define TRNG_INVALID_PARAMETER   ((unsigned long)-2)

Definition at line 16 of file trng.c.

TRNG_MAX_BITS64

#define TRNG_MAX_BITS64   192

Definition at line 19 of file trng.c.

TRNG_NO_ENTROPY

#define TRNG_NO_ENTROPY   ((unsigned long)-3)

Definition at line 17 of file trng.c.

TRNG_NOT_SUPPORTED

#define TRNG_NOT_SUPPORTED   ((unsigned long)-1)

Definition at line 15 of file trng.c.

TRNG_SUCCESS

#define TRNG_SUCCESS   0UL

Definition at line 14 of file trng.c.

Function Documentation

__aligned()

static const uuid_t arm_smc_trng_uuid __aligned ( 4  )

static

kvm_trng_call()

int kvm_trng_call

(

struct kvm_vcpu *

vcpu

)

Definition at line 51 of file trng.c.

{
    const __le32 *u = (__le32 *)arm_smc_trng_uuid.b;
    u32 func_id = smccc_get_function(vcpu);
    unsigned long val = TRNG_NOT_SUPPORTED;
    int size = 64;
 
    switch (func_id) {
    case ARM_SMCCC_TRNG_VERSION:
        val = ARM_SMCCC_TRNG_VERSION_1_0;
        break;
    case ARM_SMCCC_TRNG_FEATURES:
        switch (smccc_get_arg1(vcpu)) {
        case ARM_SMCCC_TRNG_VERSION:
        case ARM_SMCCC_TRNG_FEATURES:
        case ARM_SMCCC_TRNG_GET_UUID:
        case ARM_SMCCC_TRNG_RND32:
        case ARM_SMCCC_TRNG_RND64:
            val = TRNG_SUCCESS;
        }
        break;
    case ARM_SMCCC_TRNG_GET_UUID:
        smccc_set_retval(vcpu, le32_to_cpu(u[0]), le32_to_cpu(u[1]),
                 le32_to_cpu(u[2]), le32_to_cpu(u[3]));
        return 1;
    case ARM_SMCCC_TRNG_RND32:
        size = 32;
        fallthrough;
    case ARM_SMCCC_TRNG_RND64:
        return kvm_trng_do_rnd(vcpu, size);
    }
 
    smccc_set_retval(vcpu, val, 0, 0, 0);
    return 1;
}

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kvm_trng_do_rnd()

static int kvm_trng_do_rnd ( struct kvm_vcpu *  vcpu, int  size  )

static

Definition at line 24 of file trng.c.

{
    DECLARE_BITMAP(bits, TRNG_MAX_BITS64);
    u32 num_bits = smccc_get_arg1(vcpu);
    int i;
 
    if (num_bits > 3 * size) {
        smccc_set_retval(vcpu, TRNG_INVALID_PARAMETER, 0, 0, 0);
        return 1;
    }
 
    /* get as many bits as we need to fulfil the request */
    for (i = 0; i < DIV_ROUND_UP(num_bits, BITS_PER_LONG); i++)
        bits[i] = get_random_long();
 
    bitmap_clear(bits, num_bits, TRNG_MAX_BITS64 - num_bits);
 
    if (size == 32)
        smccc_set_retval(vcpu, TRNG_SUCCESS, lower_32_bits(bits[1]),
                 upper_32_bits(bits[0]), lower_32_bits(bits[0]));
    else
        smccc_set_retval(vcpu, TRNG_SUCCESS, bits[2], bits[1], bits[0]);
 
    memzero_explicit(bits, sizeof(bits));
    return 1;
}

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