d5ab7a34f9
This patch - unifies the old sclp early code and the sclp early printk code, so they can use common functions - makes sure all sclp early functions and variables have the same "sclp_early" prefix - converts the sclp early printk code into readable code by using existing data structures instead of hard coded magic arrays - splits the early sclp code into two files: sclp_early.c and sclp_early_core.c. The core file contains everything that is required by the kernel decompressor and may not call functions not contained within the core file. Otherwise the result would be a link error. - changes interrupt handling to be completely synchronous. The old early sclp code had a small window which allowed to receive several interrupts instead of exactly the single expected interrupt. This did hide a subtle potential bug, which is fixed with this large rework. - contains a couple of small cleanups. Reviewed-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
36 lines
785 B
C
36 lines
785 B
C
/*
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* Copyright IBM Corp. 2017
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*/
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#include <linux/console.h>
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <asm/sclp.h>
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static void sclp_early_write(struct console *con, const char *s, unsigned int len)
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{
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__sclp_early_printk(s, len);
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}
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static struct console sclp_early_console = {
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.name = "earlysclp",
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.write = sclp_early_write,
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.flags = CON_PRINTBUFFER | CON_BOOT,
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.index = -1,
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};
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static int __init setup_early_printk(char *buf)
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{
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if (early_console)
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return 0;
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/* Accept only "earlyprintk" and "earlyprintk=sclp" */
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if (buf && strncmp(buf, "sclp", 4))
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return 0;
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if (!sclp.has_linemode && !sclp.has_vt220)
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return 0;
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early_console = &sclp_early_console;
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register_console(early_console);
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return 0;
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}
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early_param("earlyprintk", setup_early_printk);
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