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printk: Use prb_first_seq() as base for 32bit seq macros
Note: This change only applies to 32bit architectures. On 64bit architectures the macros are NOPs. Currently prb_next_seq() is used as the base for the 32bit seq macros __u64seq_to_ulseq() and __ulseq_to_u64seq(). However, in a follow-up commit, prb_next_seq() will need to make use of the 32bit seq macros. Use prb_first_seq() as the base for the 32bit seq macros instead because it is guaranteed to return 64bit sequence numbers without relying on any 32bit seq macros. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20240207134103.1357162-4-john.ogness@linutronix.de Signed-off-by: Petr Mladek <pmladek@suse.com>
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@ -1832,7 +1832,7 @@ static int prb_read(struct printk_ringbuffer *rb, u64 seq,
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}
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/* Get the sequence number of the tail descriptor. */
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static u64 prb_first_seq(struct printk_ringbuffer *rb)
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u64 prb_first_seq(struct printk_ringbuffer *rb)
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{
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struct prb_desc_ring *desc_ring = &rb->desc_ring;
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enum desc_state d_state;
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@ -378,6 +378,7 @@ bool prb_read_valid(struct printk_ringbuffer *rb, u64 seq,
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bool prb_read_valid_info(struct printk_ringbuffer *rb, u64 seq,
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struct printk_info *info, unsigned int *line_count);
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u64 prb_first_seq(struct printk_ringbuffer *rb);
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u64 prb_first_valid_seq(struct printk_ringbuffer *rb);
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u64 prb_next_seq(struct printk_ringbuffer *rb);
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@ -392,12 +393,12 @@ u64 prb_next_seq(struct printk_ringbuffer *rb);
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static inline u64 __ulseq_to_u64seq(struct printk_ringbuffer *rb, u32 ulseq)
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{
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u64 rb_first_seq = prb_first_seq(rb);
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u64 seq;
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u64 rb_next_seq;
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/*
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* The provided sequence is only the lower 32 bits of the ringbuffer
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* sequence. It needs to be expanded to 64bit. Get the next sequence
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* sequence. It needs to be expanded to 64bit. Get the first sequence
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* number from the ringbuffer and fold it.
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*
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* Having a 32bit representation in the console is sufficient.
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@ -406,8 +407,7 @@ static inline u64 __ulseq_to_u64seq(struct printk_ringbuffer *rb, u32 ulseq)
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*
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* Also the access to the ring buffer is always safe.
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*/
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rb_next_seq = prb_next_seq(rb);
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seq = rb_next_seq - (s32)((u32)rb_next_seq - ulseq);
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seq = rb_first_seq - (s32)((u32)rb_first_seq - ulseq);
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return seq;
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}
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