psci-relay.c File Reference

#include <asm/kvm_asm.h>
#include <asm/kvm_hyp.h>
#include <asm/kvm_mmu.h>
#include <linux/arm-smccc.h>
#include <linux/kvm_host.h>
#include <uapi/linux/psci.h>
#include <nvhe/memory.h>
#include <nvhe/trap_handler.h>

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Classes
struct	psci_boot_args

Macros
#define	INVALID_CPU_ID   UINT_MAX
#define	PSCI_BOOT_ARGS_UNLOCKED   0
#define	PSCI_BOOT_ARGS_LOCKED   1
#define	PSCI_BOOT_ARGS_INIT
#define	is_psci_0_1(what, func_id)

Functions
void	kvm_hyp_cpu_entry (unsigned long r0)
void	kvm_hyp_cpu_resume (unsigned long r0)
void __noreturn	__host_enter (struct kvm_cpu_context *host_ctxt)
static	DEFINE_PER_CPU (struct psci_boot_args, cpu_on_args)
static	DEFINE_PER_CPU (struct psci_boot_args, suspend_args)
static bool	is_psci_0_1_call (u64 func_id)
static bool	is_psci_0_2_call (u64 func_id)
static unsigned long	psci_call (unsigned long fn, unsigned long arg0, unsigned long arg1, unsigned long arg2)
static unsigned long	psci_forward (struct kvm_cpu_context *host_ctxt)
static unsigned int	find_cpu_id (u64 mpidr)
static __always_inline bool	try_acquire_boot_args (struct psci_boot_args *args)
static __always_inline void	release_boot_args (struct psci_boot_args *args)
static int	psci_cpu_on (u64 func_id, struct kvm_cpu_context *host_ctxt)
static int	psci_cpu_suspend (u64 func_id, struct kvm_cpu_context *host_ctxt)
static int	psci_system_suspend (u64 func_id, struct kvm_cpu_context *host_ctxt)
asmlinkage void __noreturn	__kvm_host_psci_cpu_entry (bool is_cpu_on)
static unsigned long	psci_0_1_handler (u64 func_id, struct kvm_cpu_context *host_ctxt)
static unsigned long	psci_0_2_handler (u64 func_id, struct kvm_cpu_context *host_ctxt)
static unsigned long	psci_1_0_handler (u64 func_id, struct kvm_cpu_context *host_ctxt)
bool	kvm_host_psci_handler (struct kvm_cpu_context *host_ctxt, u32 func_id)

Variables
struct kvm_host_psci_config __ro_after_init	kvm_host_psci_config

Macro Definition Documentation

INVALID_CPU_ID

#define INVALID_CPU_ID   UINT_MAX

Definition at line 25 of file psci-relay.c.

is_psci_0_1

#define is_psci_0_1	(		what,
			func_id
	)

Value:

    (kvm_host_psci_config.psci_0_1_ ## what ## _implemented &&  \
     (func_id) == kvm_host_psci_config.function_ids_0_1.what)

Definition at line 44 of file psci-relay.c.

PSCI_BOOT_ARGS_INIT

#define PSCI_BOOT_ARGS_INIT

Value:

    ((struct psci_boot_args){               \
        .lock = ATOMIC_INIT(PSCI_BOOT_ARGS_UNLOCKED),   \
    })

Definition at line 36 of file psci-relay.c.

PSCI_BOOT_ARGS_LOCKED

#define PSCI_BOOT_ARGS_LOCKED   1

Definition at line 34 of file psci-relay.c.

PSCI_BOOT_ARGS_UNLOCKED

#define PSCI_BOOT_ARGS_UNLOCKED   0

Definition at line 33 of file psci-relay.c.

Function Documentation

__host_enter()

void __noreturn __host_enter

(

struct kvm_cpu_context *

host_ctxt

)

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__kvm_host_psci_cpu_entry()

asmlinkage void __noreturn __kvm_host_psci_cpu_entry

(

bool

is_cpu_on

)

Definition at line 203 of file psci-relay.c.

{
    struct psci_boot_args *boot_args;
    struct kvm_cpu_context *host_ctxt;
 
    host_ctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt;
 
    if (is_cpu_on)
        boot_args = this_cpu_ptr(&cpu_on_args);
    else
        boot_args = this_cpu_ptr(&suspend_args);
 
    cpu_reg(host_ctxt, 0) = boot_args->r0;
    write_sysreg_el2(boot_args->pc, SYS_ELR);
 
    if (is_cpu_on)
        release_boot_args(boot_args);
 
    __host_enter(host_ctxt);
}

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DEFINE_PER_CPU() [1/2]

static DEFINE_PER_CPU ( struct psci_boot_args  , cpu_on_args    )

static

DEFINE_PER_CPU() [2/2]

static DEFINE_PER_CPU ( struct psci_boot_args  , suspend_args    )

static

find_cpu_id()

static unsigned int find_cpu_id ( u64  mpidr )

static

Definition at line 78 of file psci-relay.c.

{
    unsigned int i;
 
    /* Reject invalid MPIDRs */
    if (mpidr & ~MPIDR_HWID_BITMASK)
        return INVALID_CPU_ID;
 
    for (i = 0; i < NR_CPUS; i++) {
        if (cpu_logical_map(i) == mpidr)
            return i;
    }
 
    return INVALID_CPU_ID;
}

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is_psci_0_1_call()

static bool is_psci_0_1_call ( u64  func_id )

static

Definition at line 48 of file psci-relay.c.

{
    return (is_psci_0_1(cpu_suspend, func_id) ||
        is_psci_0_1(cpu_on, func_id) ||
        is_psci_0_1(cpu_off, func_id) ||
        is_psci_0_1(migrate, func_id));
}

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is_psci_0_2_call()

static bool is_psci_0_2_call ( u64  func_id )

static

Definition at line 56 of file psci-relay.c.

{
    /* SMCCC reserves IDs 0x00-1F with the given 32/64-bit base for PSCI. */
    return (PSCI_0_2_FN(0) <= func_id && func_id <= PSCI_0_2_FN(31)) ||
           (PSCI_0_2_FN64(0) <= func_id && func_id <= PSCI_0_2_FN64(31));
}

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kvm_host_psci_handler()

bool kvm_host_psci_handler	(	struct kvm_cpu_context *	host_ctxt,
		u32	func_id
	)

Definition at line 276 of file psci-relay.c.

{
    unsigned long ret;
 
    switch (kvm_host_psci_config.version) {
    case PSCI_VERSION(0, 1):
        if (!is_psci_0_1_call(func_id))
            return false;
        ret = psci_0_1_handler(func_id, host_ctxt);
        break;
    case PSCI_VERSION(0, 2):
        if (!is_psci_0_2_call(func_id))
            return false;
        ret = psci_0_2_handler(func_id, host_ctxt);
        break;
    default:
        if (!is_psci_0_2_call(func_id))
            return false;
        ret = psci_1_0_handler(func_id, host_ctxt);
        break;
    }
 
    cpu_reg(host_ctxt, 0) = ret;
    cpu_reg(host_ctxt, 1) = 0;
    cpu_reg(host_ctxt, 2) = 0;
    cpu_reg(host_ctxt, 3) = 0;
    return true;
}

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kvm_hyp_cpu_entry()

void kvm_hyp_cpu_entry

(

unsigned long

r0

)

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kvm_hyp_cpu_resume()

void kvm_hyp_cpu_resume

(

unsigned long

r0

)

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psci_0_1_handler()

static unsigned long psci_0_1_handler ( u64  func_id, struct kvm_cpu_context *  host_ctxt  )

static

Definition at line 224 of file psci-relay.c.

{
    if (is_psci_0_1(cpu_off, func_id) || is_psci_0_1(migrate, func_id))
        return psci_forward(host_ctxt);
    if (is_psci_0_1(cpu_on, func_id))
        return psci_cpu_on(func_id, host_ctxt);
    if (is_psci_0_1(cpu_suspend, func_id))
        return psci_cpu_suspend(func_id, host_ctxt);
 
    return PSCI_RET_NOT_SUPPORTED;
}

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psci_0_2_handler()

static unsigned long psci_0_2_handler ( u64  func_id, struct kvm_cpu_context *  host_ctxt  )

static

Definition at line 236 of file psci-relay.c.

{
    switch (func_id) {
    case PSCI_0_2_FN_PSCI_VERSION:
    case PSCI_0_2_FN_CPU_OFF:
    case PSCI_0_2_FN64_AFFINITY_INFO:
    case PSCI_0_2_FN64_MIGRATE:
    case PSCI_0_2_FN_MIGRATE_INFO_TYPE:
    case PSCI_0_2_FN64_MIGRATE_INFO_UP_CPU:
        return psci_forward(host_ctxt);
    /*
     * SYSTEM_OFF/RESET should not return according to the spec.
     * Allow it so as to stay robust to broken firmware.
     */
    case PSCI_0_2_FN_SYSTEM_OFF:
    case PSCI_0_2_FN_SYSTEM_RESET:
        return psci_forward(host_ctxt);
    case PSCI_0_2_FN64_CPU_SUSPEND:
        return psci_cpu_suspend(func_id, host_ctxt);
    case PSCI_0_2_FN64_CPU_ON:
        return psci_cpu_on(func_id, host_ctxt);
    default:
        return PSCI_RET_NOT_SUPPORTED;
    }
}

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psci_1_0_handler()

static unsigned long psci_1_0_handler ( u64  func_id, struct kvm_cpu_context *  host_ctxt  )

static

Definition at line 262 of file psci-relay.c.

{
    switch (func_id) {
    case PSCI_1_0_FN_PSCI_FEATURES:
    case PSCI_1_0_FN_SET_SUSPEND_MODE:
    case PSCI_1_1_FN64_SYSTEM_RESET2:
        return psci_forward(host_ctxt);
    case PSCI_1_0_FN64_SYSTEM_SUSPEND:
        return psci_system_suspend(func_id, host_ctxt);
    default:
        return psci_0_2_handler(func_id, host_ctxt);
    }
}

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psci_call()

static unsigned long psci_call ( unsigned long  fn, unsigned long  arg0, unsigned long  arg1, unsigned long  arg2  )

static

Definition at line 63 of file psci-relay.c.

{
    struct arm_smccc_res res;
 
    arm_smccc_1_1_smc(fn, arg0, arg1, arg2, &res);
    return res.a0;
}

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psci_cpu_on()

static int psci_cpu_on ( u64  func_id, struct kvm_cpu_context *  host_ctxt  )

static

Definition at line 107 of file psci-relay.c.

{
    DECLARE_REG(u64, mpidr, host_ctxt, 1);
    DECLARE_REG(unsigned long, pc, host_ctxt, 2);
    DECLARE_REG(unsigned long, r0, host_ctxt, 3);
 
    unsigned int cpu_id;
    struct psci_boot_args *boot_args;
    struct kvm_nvhe_init_params *init_params;
    int ret;
 
    /*
     * Find the logical CPU ID for the given MPIDR. The search set is
     * the set of CPUs that were online at the point of KVM initialization.
     * Booting other CPUs is rejected because their cpufeatures were not
     * checked against the finalized capabilities. This could be relaxed
     * by doing the feature checks in hyp.
     */
    cpu_id = find_cpu_id(mpidr);
    if (cpu_id == INVALID_CPU_ID)
        return PSCI_RET_INVALID_PARAMS;
 
    boot_args = per_cpu_ptr(&cpu_on_args, cpu_id);
    init_params = per_cpu_ptr(&kvm_init_params, cpu_id);
 
    /* Check if the target CPU is already being booted. */
    if (!try_acquire_boot_args(boot_args))
        return PSCI_RET_ALREADY_ON;
 
    boot_args->pc = pc;
    boot_args->r0 = r0;
    wmb();
 
    ret = psci_call(func_id, mpidr,
            __hyp_pa(&kvm_hyp_cpu_entry),
            __hyp_pa(init_params));
 
    /* If successful, the lock will be released by the target CPU. */
    if (ret != PSCI_RET_SUCCESS)
        release_boot_args(boot_args);
 
    return ret;
}

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psci_cpu_suspend()

static int psci_cpu_suspend ( u64  func_id, struct kvm_cpu_context *  host_ctxt  )

static

Definition at line 151 of file psci-relay.c.

{
    DECLARE_REG(u64, power_state, host_ctxt, 1);
    DECLARE_REG(unsigned long, pc, host_ctxt, 2);
    DECLARE_REG(unsigned long, r0, host_ctxt, 3);
 
    struct psci_boot_args *boot_args;
    struct kvm_nvhe_init_params *init_params;
 
    boot_args = this_cpu_ptr(&suspend_args);
    init_params = this_cpu_ptr(&kvm_init_params);
 
    /*
     * No need to acquire a lock before writing to boot_args because a core
     * can only suspend itself. Racy CPU_ON calls use a separate struct.
     */
    boot_args->pc = pc;
    boot_args->r0 = r0;
 
    /*
     * Will either return if shallow sleep state, or wake up into the entry
     * point if it is a deep sleep state.
     */
    return psci_call(func_id, power_state,
             __hyp_pa(&kvm_hyp_cpu_resume),
             __hyp_pa(init_params));
}

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psci_forward()

static unsigned long psci_forward ( struct kvm_cpu_context *  host_ctxt )

static

Definition at line 72 of file psci-relay.c.

{
    return psci_call(cpu_reg(host_ctxt, 0), cpu_reg(host_ctxt, 1),
             cpu_reg(host_ctxt, 2), cpu_reg(host_ctxt, 3));
}

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psci_system_suspend()

static int psci_system_suspend ( u64  func_id, struct kvm_cpu_context *  host_ctxt  )

static

Definition at line 179 of file psci-relay.c.

{
    DECLARE_REG(unsigned long, pc, host_ctxt, 1);
    DECLARE_REG(unsigned long, r0, host_ctxt, 2);
 
    struct psci_boot_args *boot_args;
    struct kvm_nvhe_init_params *init_params;
 
    boot_args = this_cpu_ptr(&suspend_args);
    init_params = this_cpu_ptr(&kvm_init_params);
 
    /*
     * No need to acquire a lock before writing to boot_args because a core
     * can only suspend itself. Racy CPU_ON calls use a separate struct.
     */
    boot_args->pc = pc;
    boot_args->r0 = r0;
 
    /* Will only return on error. */
    return psci_call(func_id,
             __hyp_pa(&kvm_hyp_cpu_resume),
             __hyp_pa(init_params), 0);
}

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release_boot_args()

static __always_inline void release_boot_args ( struct psci_boot_args *  args )

static

Definition at line 102 of file psci-relay.c.

{
    atomic_set_release(&args->lock, PSCI_BOOT_ARGS_UNLOCKED);
}

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try_acquire_boot_args()

static __always_inline bool try_acquire_boot_args ( struct psci_boot_args *  args )

static

Definition at line 94 of file psci-relay.c.

{
    return atomic_cmpxchg_acquire(&args->lock,
                      PSCI_BOOT_ARGS_UNLOCKED,
                      PSCI_BOOT_ARGS_LOCKED) ==
        PSCI_BOOT_ARGS_UNLOCKED;
}

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Variable Documentation

kvm_host_psci_config

struct kvm_host_psci_config __ro_after_init kvm_host_psci_config

Definition at line 20 of file psci-relay.c.