batch.h

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/* SPDX-License-Identifier: GPL-2.0-or-later */
 
#ifndef TARGET__RISCV__SCANS_H
#define TARGET__RISCV__SCANS_H
 
#include "target/target.h"
#include "jtag/jtag.h"
#include "riscv.h"
 
enum riscv_scan_type {
    RISCV_SCAN_TYPE_INVALID,
    RISCV_SCAN_TYPE_NOP,
    RISCV_SCAN_TYPE_READ,
    RISCV_SCAN_TYPE_WRITE,
};
 
/* A batch of multiple JTAG scans, which are grouped together to avoid the
 * overhead of some JTAG adapters when sending single commands.  This is
 * designed to support block copies, as that's what we actually need to go
 * fast. */
struct riscv_batch {
    struct target *target;
 
    size_t allocated_scans;
    size_t used_scans;
 
    size_t idle_count;
 
    uint8_t *data_out;
    uint8_t *data_in;
    struct scan_field *fields;
 
    /* If in BSCAN mode, this field will be allocated (one per scan),
       and utilized to tunnel all the scans in the batch.  If not in
       BSCAN mode, this field is unallocated and stays NULL */
    riscv_bscan_tunneled_scan_context_t *bscan_ctxt;
 
    /* In JTAG we scan out the previous value's output when performing a
     * scan.  This is a pain for users, so we just provide them the
     * illusion of not having to do this by eliding all but the last NOP.
     * */
    enum riscv_scan_type last_scan;
 
    /* The read keys. */
    size_t *read_keys;
    size_t read_keys_used;
};
 
/* Allocates (or frees) a new scan set.  "scans" is the maximum number of JTAG
 * scans that can be issued to this object, and idle is the number of JTAG idle
 * cycles between every real scan. */
struct riscv_batch *riscv_batch_alloc(struct target *target, size_t scans, size_t idle);
void riscv_batch_free(struct riscv_batch *batch);
 
/* Checks to see if this batch is full. */
bool riscv_batch_full(struct riscv_batch *batch);
 
/* Executes this scan batch. */
int riscv_batch_run(struct riscv_batch *batch);
 
/* Adds a DMI write to this batch. */
void riscv_batch_add_dmi_write(struct riscv_batch *batch, unsigned address, uint64_t data);
 
/* DMI reads must be handled in two parts: the first one schedules a read and
 * provides a key, the second one actually obtains the result of the read -
 * status (op) and the actual data. */
size_t riscv_batch_add_dmi_read(struct riscv_batch *batch, unsigned address);
unsigned riscv_batch_get_dmi_read_op(struct riscv_batch *batch, size_t key);
uint32_t riscv_batch_get_dmi_read_data(struct riscv_batch *batch, size_t key);
 
/* Scans in a NOP. */
void riscv_batch_add_nop(struct riscv_batch *batch);
 
/* Returns the number of available scans. */
size_t riscv_batch_available_scans(struct riscv_batch *batch);
 
#endif