root/src/runtime/qurt_hvx.cpp

DEFINITIONS

1. halide_qurt_hvx_lock
2. halide_qurt_hvx_unlock
3. halide_qurt_hvx_unlock_as_destructor
4. _halide_prefetch_2d
5. _halide_prefetch
6. _halide_hexagon_buffer_get_host
7. _halide_hexagon_buffer_get_device

#include "runtime_internal.h"
#include "HalideRuntimeQurt.h"
#include "printer.h"
#include "mini_qurt.h"

using namespace Halide::Runtime::Internal::Qurt;

extern "C" {

enum qurt_hvx_mode_t {
    QURT_HVX_MODE_64B = 0,
    QURT_HVX_MODE_128B = 1,
};

extern int qurt_hvx_lock(qurt_hvx_mode_t);
extern int qurt_hvx_unlock();

WEAK int halide_qurt_hvx_lock(void *user_context, int size) {
    qurt_hvx_mode_t mode;
    switch (size) {
    case 64: mode = QURT_HVX_MODE_64B; break;
    case 128: mode = QURT_HVX_MODE_128B; break;
    default:
        error(user_context) << "HVX lock size must be 64 or 128.\n";
        return -1;
    }

    debug(user_context) << "QuRT: qurt_hvx_lock(" << mode << ") ->\n";
    int result = qurt_hvx_lock(mode);
    debug(user_context) << "        " << result << "\n";
    if (result != QURT_EOK) {
        error(user_context) << "qurt_hvx_lock failed\n";
        return -1;
    }

    return 0;
}

WEAK int halide_qurt_hvx_unlock(void *user_context) {
    debug(user_context) << "QuRT: qurt_hvx_unlock ->\n";
    int result = qurt_hvx_unlock();
    debug(user_context) << "        " << result << "\n";
    if (result != QURT_EOK) {
        error(user_context) << "qurt_hvx_unlock failed\n";
        return -1;
    }

    return 0;
}

WEAK void halide_qurt_hvx_unlock_as_destructor(void *user_context, void * /*obj*/) {
    halide_qurt_hvx_unlock(user_context);
}

// These need to inline, otherwise the extern call with the ptr
// parameter breaks a lot of optimizations.
__attribute__((always_inline))
WEAK int _halide_prefetch_2d(const void *ptr, int width_bytes, int height, int stride_bytes) {
    // Notes:
    //  - Prefetches can be queued up to 3 deep (MAX_PREFETCH)
    //  - If 3 are already pending, the oldest request is dropped
    //  - USR:PFA status bit is set to indicate that prefetches are in progress
    //  - A l2fetch with any subfield set to zero cancels all pending prefetches
    //  - The l2fetch starting address must be in mapped memory but the range
    //    prefetched can go into unmapped memory without raising an exception
    const int dir = 1;
    uint64_t desc =
        (static_cast<uint64_t>(dir) << 48) |
        (static_cast<uint64_t>(stride_bytes) << 32) |
        (static_cast<uint64_t>(width_bytes) << 16) |
        (static_cast<uint64_t>(height) << 0);
    __asm__ __volatile__ ("l2fetch(%0,%1)" : : "r"(ptr), "r"(desc));
    return 0;
}

__attribute__((always_inline))
WEAK int _halide_prefetch(const void *ptr, int size) {
    _halide_prefetch_2d(ptr, size, 1, 1);
    return 0;
}

struct hexagon_buffer_t_arg {
    uint64_t device;
    uint8_t* host;
};

__attribute__((always_inline))
WEAK uint8_t *_halide_hexagon_buffer_get_host(const hexagon_buffer_t_arg *buf) {
    return buf->host;
}

__attribute__((always_inline))
WEAK uint64_t _halide_hexagon_buffer_get_device(const hexagon_buffer_t_arg *buf) {
    return buf->device;
}

}