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    Subject[PATCH printk v5 1/6] printk: ringbuffer: relocate get_data()
    Date
    Move the internal get_data() function as-is above prb_reserve() so
    that a later change can make use of the static function.

    Signed-off-by: John Ogness <john.ogness@linutronix.de>
    Reviewed-by: Petr Mladek <pmladek@suse.com>
    ---
    kernel/printk/printk_ringbuffer.c | 116 +++++++++++++++---------------
    1 file changed, 58 insertions(+), 58 deletions(-)

    diff --git a/kernel/printk/printk_ringbuffer.c b/kernel/printk/printk_ringbuffer.c
    index 0659b50872b5..aa6e31a27601 100644
    --- a/kernel/printk/printk_ringbuffer.c
    +++ b/kernel/printk/printk_ringbuffer.c
    @@ -1038,6 +1038,64 @@ static unsigned int space_used(struct prb_data_ring *data_ring,
    DATA_SIZE(data_ring) - DATA_INDEX(data_ring, blk_lpos->begin));
    }

    +/*
    + * Given @blk_lpos, return a pointer to the writer data from the data block
    + * and calculate the size of the data part. A NULL pointer is returned if
    + * @blk_lpos specifies values that could never be legal.
    + *
    + * This function (used by readers) performs strict validation on the lpos
    + * values to possibly detect bugs in the writer code. A WARN_ON_ONCE() is
    + * triggered if an internal error is detected.
    + */
    +static const char *get_data(struct prb_data_ring *data_ring,
    + struct prb_data_blk_lpos *blk_lpos,
    + unsigned int *data_size)
    +{
    + struct prb_data_block *db;
    +
    + /* Data-less data block description. */
    + if (LPOS_DATALESS(blk_lpos->begin) && LPOS_DATALESS(blk_lpos->next)) {
    + if (blk_lpos->begin == NO_LPOS && blk_lpos->next == NO_LPOS) {
    + *data_size = 0;
    + return "";
    + }
    + return NULL;
    + }
    +
    + /* Regular data block: @begin less than @next and in same wrap. */
    + if (DATA_WRAPS(data_ring, blk_lpos->begin) == DATA_WRAPS(data_ring, blk_lpos->next) &&
    + blk_lpos->begin < blk_lpos->next) {
    + db = to_block(data_ring, blk_lpos->begin);
    + *data_size = blk_lpos->next - blk_lpos->begin;
    +
    + /* Wrapping data block: @begin is one wrap behind @next. */
    + } else if (DATA_WRAPS(data_ring, blk_lpos->begin + DATA_SIZE(data_ring)) ==
    + DATA_WRAPS(data_ring, blk_lpos->next)) {
    + db = to_block(data_ring, 0);
    + *data_size = DATA_INDEX(data_ring, blk_lpos->next);
    +
    + /* Illegal block description. */
    + } else {
    + WARN_ON_ONCE(1);
    + return NULL;
    + }
    +
    + /* A valid data block will always be aligned to the ID size. */
    + if (WARN_ON_ONCE(blk_lpos->begin != ALIGN(blk_lpos->begin, sizeof(db->id))) ||
    + WARN_ON_ONCE(blk_lpos->next != ALIGN(blk_lpos->next, sizeof(db->id)))) {
    + return NULL;
    + }
    +
    + /* A valid data block will always have at least an ID. */
    + if (WARN_ON_ONCE(*data_size < sizeof(db->id)))
    + return NULL;
    +
    + /* Subtract block ID space from size to reflect data size. */
    + *data_size -= sizeof(db->id);
    +
    + return &db->data[0];
    +}
    +
    /**
    * prb_reserve() - Reserve space in the ringbuffer.
    *
    @@ -1192,64 +1250,6 @@ void prb_commit(struct prb_reserved_entry *e)
    local_irq_restore(e->irqflags);
    }

    -/*
    - * Given @blk_lpos, return a pointer to the writer data from the data block
    - * and calculate the size of the data part. A NULL pointer is returned if
    - * @blk_lpos specifies values that could never be legal.
    - *
    - * This function (used by readers) performs strict validation on the lpos
    - * values to possibly detect bugs in the writer code. A WARN_ON_ONCE() is
    - * triggered if an internal error is detected.
    - */
    -static const char *get_data(struct prb_data_ring *data_ring,
    - struct prb_data_blk_lpos *blk_lpos,
    - unsigned int *data_size)
    -{
    - struct prb_data_block *db;
    -
    - /* Data-less data block description. */
    - if (LPOS_DATALESS(blk_lpos->begin) && LPOS_DATALESS(blk_lpos->next)) {
    - if (blk_lpos->begin == NO_LPOS && blk_lpos->next == NO_LPOS) {
    - *data_size = 0;
    - return "";
    - }
    - return NULL;
    - }
    -
    - /* Regular data block: @begin less than @next and in same wrap. */
    - if (DATA_WRAPS(data_ring, blk_lpos->begin) == DATA_WRAPS(data_ring, blk_lpos->next) &&
    - blk_lpos->begin < blk_lpos->next) {
    - db = to_block(data_ring, blk_lpos->begin);
    - *data_size = blk_lpos->next - blk_lpos->begin;
    -
    - /* Wrapping data block: @begin is one wrap behind @next. */
    - } else if (DATA_WRAPS(data_ring, blk_lpos->begin + DATA_SIZE(data_ring)) ==
    - DATA_WRAPS(data_ring, blk_lpos->next)) {
    - db = to_block(data_ring, 0);
    - *data_size = DATA_INDEX(data_ring, blk_lpos->next);
    -
    - /* Illegal block description. */
    - } else {
    - WARN_ON_ONCE(1);
    - return NULL;
    - }
    -
    - /* A valid data block will always be aligned to the ID size. */
    - if (WARN_ON_ONCE(blk_lpos->begin != ALIGN(blk_lpos->begin, sizeof(db->id))) ||
    - WARN_ON_ONCE(blk_lpos->next != ALIGN(blk_lpos->next, sizeof(db->id)))) {
    - return NULL;
    - }
    -
    - /* A valid data block will always have at least an ID. */
    - if (WARN_ON_ONCE(*data_size < sizeof(db->id)))
    - return NULL;
    -
    - /* Subtract block ID space from size to reflect data size. */
    - *data_size -= sizeof(db->id);
    -
    - return &db->data[0];
    -}
    -
    /*
    * Count the number of lines in provided text. All text has at least 1 line
    * (even if @text_size is 0). Each '\n' processed is counted as an additional
    --
    2.20.1
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