drm: drm_printer: Add printer for devcoredump (cfc57a18) · Commits · 戴 / test

drivers/gpu/drm/drm_print.c

+74 −0

Original line number	Diff line number	Diff line
		@@ -30,6 +30,80 @@
		#include <drm/drmP.h>
		#include <drm/drm_print.h>

		void __drm_printfn_coredump(struct drm_printer p, struct va_format vaf)
		{
		struct drm_print_iterator *iterator = p->arg;
		ssize_t len;

		if (!iterator->remain)
		return;

		/* Figure out how big the string will be */
		len = snprintf(NULL, 0, "%pV", vaf);

		if (iterator->offset < iterator->start) {
		char *buf;
		ssize_t copy;

		if (iterator->offset + len <= iterator->start) {
		iterator->offset += len;
		return;
		}

		/* Print the string into a temporary buffer */
		buf = kmalloc(len + 1,
		GFP_KERNEL \| __GFP_NOWARN \| __GFP_NORETRY);
		if (!buf)
		return;

		snprintf(buf, len + 1, "%pV", vaf);

		copy = len - (iterator->start - iterator->offset);

		if (copy > iterator->remain)
		copy = iterator->remain;

		/* Copy out the bit of the string that we need */
		memcpy(iterator->data,
		buf + (iterator->start - iterator->offset), copy);

		iterator->offset = iterator->start + copy;
		iterator->remain -= copy;

		kfree(buf);
		} else {
		char *buf;
		ssize_t pos = iterator->offset - iterator->start;

		if (len < iterator->remain) {
		snprintf(((char *) iterator->data) + pos,
		iterator->remain, "%pV", vaf);

		iterator->offset += len;
		iterator->remain -= len;

		return;
		}

		/* Print the string into a temporary buffer */
		buf = kmalloc(len + 1,
		GFP_KERNEL \| __GFP_NOWARN \| __GFP_NORETRY);
		if (!buf)
		return;

		snprintf(buf, len + 1, "%pV", vaf);

		/* Copy out the remaining bits */
		memcpy(iterator->data + pos, buf, iterator->remain);

		iterator->offset += iterator->remain;
		iterator->remain = 0;

		kfree(buf);
		}
		}
		EXPORT_SYMBOL(__drm_printfn_coredump);

		void __drm_printfn_seq_file(struct drm_printer p, struct va_format vaf)
		{
		seq_printf(p->arg, "%pV", vaf);

include/drm/drm_print.h

+65 −0

Original line number	Diff line number	Diff line
		@@ -73,6 +73,7 @@ struct drm_printer {
		const char *prefix;
		};

		void __drm_printfn_coredump(struct drm_printer p, struct va_format vaf);
		void __drm_printfn_seq_file(struct drm_printer p, struct va_format vaf);
		void __drm_printfn_info(struct drm_printer p, struct va_format vaf);
		void __drm_printfn_debug(struct drm_printer p, struct va_format vaf);
		@@ -104,6 +105,70 @@ drm_vprintf(struct drm_printer p, const char fmt, va_list *va)
		#define drm_printf_indent(printer, indent, fmt, ...) \
		drm_printf((printer), "%.*s" fmt, (indent), "\t\t\t\t\tX", ##__VA_ARGS__)

		/**
		* struct drm_print_iterator - local struct used with drm_printer_coredump
		* @data: Pointer to the devcoredump output buffer
		* @start: The offset within the buffer to start writing
		* @remain: The number of bytes to write for this iteration
		*/
		struct drm_print_iterator {
		void *data;
		ssize_t start;
		ssize_t remain;
		/* private: */
		ssize_t offset;
		};

		/**
		* drm_coredump_printer - construct a &drm_printer that can output to a buffer
		* from the read function for devcoredump
		* @iter: A pointer to a struct drm_print_iterator for the read instance
		*
		* This wrapper extends drm_printf() to work with a dev_coredumpm() callback
		* function. The passed in drm_print_iterator struct contains the buffer
		* pointer, size and offset as passed in from devcoredump.
		*
		* For example::
		*
		* void coredump_read(char *buffer, loff_t offset, size_t count,
		* void *data, size_t datalen)
		* {
		* struct drm_print_iterator iter;
		* struct drm_printer p;
		*
		* iter.data = buffer;
		* iter.start = offset;
		* iter.remain = count;
		*
		* p = drm_coredump_printer(&iter);
		*
		* drm_printf(p, "foo=%d\n", foo);
		* }
		*
		* void makecoredump(...)
		* {
		* ...
		* dev_coredumpm(dev, THIS_MODULE, data, 0, GFP_KERNEL,
		* coredump_read, ...)
		* }
		*
		* RETURNS:
		* The &drm_printer object
		*/
		static inline struct drm_printer
		drm_coredump_printer(struct drm_print_iterator *iter)
		{
		struct drm_printer p = {
		.printfn = __drm_printfn_coredump,
		.arg = iter,
		};

		/* Set the internal offset of the iterator to zero */
		iter->offset = 0;

		return p;
		}

		/**
		* drm_seq_file_printer - construct a &drm_printer that outputs to &seq_file
		* @f: the &struct seq_file to output to

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