[flashrom] [RFC] use linux kernel list datastruct for registered masters list

Antony Pavlov antonynpavlov at gmail.com
Wed Jun 17 09:46:54 CEST 2015


On Mon, 15 Jun 2015 02:05:39 +0300
Antony Pavlov <antonynpavlov at gmail.com> wrote:

Stefan!

This patch make it possible to eliminate MASTERS_MAX limit.

Could you please comment on this patch?

> Signed-off-by: Antony Pavlov <antonynpavlov at gmail.com>
> ---
>  cli_classic.c |  13 +++---
>  flashrom.c    |   1 -
>  list.h        | 130 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
>  programmer.c  |  27 ++++++------
>  programmer.h  |   7 ++--
>  5 files changed, 153 insertions(+), 25 deletions(-)
> 
> diff --git a/cli_classic.c b/cli_classic.c
> index a2c2014..06ae454 100644
> --- a/cli_classic.c
> +++ b/cli_classic.c
> @@ -96,7 +96,7 @@ int main(int argc, char *argv[])
>  	struct flashctx flashes[8] = {{0}};
>  	struct flashctx *fill_flash;
>  	const char *name;
> -	int namelen, opt, i, j;
> +	int namelen, opt, i;
>  	int startchip = -1, chipcount = 0, option_index = 0, force = 0;
>  #if CONFIG_PRINT_WIKI == 1
>  	int list_supported_wiki = 0;
> @@ -134,6 +134,7 @@ int main(int argc, char *argv[])
>  #endif /* !STANDALONE */
>  	char *tempstr = NULL;
>  	char *pparam = NULL;
> +	struct registered_master *master;
>  
>  	print_version();
>  	print_banner();
> @@ -425,10 +426,10 @@ int main(int argc, char *argv[])
>  	msg_pdbg("The following protocols are supported: %s.\n", tempstr);
>  	free(tempstr);
>  
> -	for (j = 0; j < registered_master_count; j++) {
> +	list_for_each_entry(master, &registered_masters, node) {
>  		startchip = 0;
>  		while (chipcount < ARRAY_SIZE(flashes)) {
> -			startchip = probe_flash(&registered_masters[j], startchip, &flashes[chipcount], 0);
> +			startchip = probe_flash(master, startchip, &flashes[chipcount], 0);
>  			if (startchip == -1)
>  				break;
>  			chipcount++;
> @@ -455,8 +456,7 @@ int main(int argc, char *argv[])
>  			int compatible_masters = 0;
>  			msg_cinfo("Force read (-f -r -c) requested, pretending the chip is there:\n");
>  			/* This loop just counts compatible controllers. */
> -			for (j = 0; j < registered_master_count; j++) {
> -				mst = &registered_masters[j];
> +			list_for_each_entry(mst, &registered_masters, node) {
>  				/* chip is still set from the chip_to_probe earlier in this function. */
>  				if (mst->buses_supported & chip->bustype)
>  					compatible_masters++;
> @@ -469,8 +469,7 @@ int main(int argc, char *argv[])
>  			if (compatible_masters > 1)
>  				msg_cinfo("More than one compatible controller found for the requested flash "
>  					  "chip, using the first one.\n");
> -			for (j = 0; j < registered_master_count; j++) {
> -				mst = &registered_masters[j];
> +			list_for_each_entry(mst, &registered_masters, node) {
>  				startchip = probe_flash(mst, 0, &flashes[0], 1);
>  				if (startchip != -1)
>  					break;
> diff --git a/flashrom.c b/flashrom.c
> index a389cb2..bd770c2 100644
> --- a/flashrom.c
> +++ b/flashrom.c
> @@ -494,7 +494,6 @@ int programmer_shutdown(void)
>  	}
>  
>  	programmer_param = NULL;
> -	registered_master_count = 0;
>  
>  	return ret;
>  }
> diff --git a/list.h b/list.h
> new file mode 100644
> index 0000000..7567742
> --- /dev/null
> +++ b/list.h
> @@ -0,0 +1,130 @@
> +#ifndef LIST_H
> +#define LIST_H
> +
> +/*
> + * Copied from include/linux/...
> + */
> +
> +#undef offsetof
> +#define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
> +
> +/**
> + * container_of - cast a member of a structure out to the containing structure
> + * @ptr:        the pointer to the member.
> + * @type:       the type of the container struct this is embedded in.
> + * @member:     the name of the member within the struct.
> + *
> + */
> +#define container_of(ptr, type, member) ({                      \
> +	const typeof( ((type *)0)->member ) *__mptr = (ptr);    \
> +	(type *)( (char *)__mptr - offsetof(type,member) );})
> +
> +
> +struct list_head {
> +	struct list_head *next, *prev;
> +};
> +
> +#define LIST_HEAD_INIT(name) { &(name), &(name) }
> +
> +#define LIST_HEAD(name) \
> +	struct list_head name = LIST_HEAD_INIT(name)
> +
> +/**
> + * list_entry - get the struct for this entry
> + * @ptr:	the &struct list_head pointer.
> + * @type:	the type of the struct this is embedded in.
> + * @member:	the name of the list_head within the struct.
> + */
> +#define list_entry(ptr, type, member) \
> +	container_of(ptr, type, member)
> +
> +/**
> + * list_for_each_entry	-	iterate over list of given type
> + * @pos:	the type * to use as a loop cursor.
> + * @head:	the head for your list.
> + * @member:	the name of the list_head within the struct.
> + */
> +#define list_for_each_entry(pos, head, member)				\
> +	for (pos = list_entry((head)->next, typeof(*pos), member);	\
> +	     &pos->member != (head);	\
> +	     pos = list_entry(pos->member.next, typeof(*pos), member))
> +
> +/**
> + * list_for_each_entry_safe - iterate over list of given type safe against removal of list entry
> + * @pos:	the type * to use as a loop cursor.
> + * @n:		another type * to use as temporary storage
> + * @head:	the head for your list.
> + * @member:	the name of the list_head within the struct.
> + */
> +#define list_for_each_entry_safe(pos, n, head, member)			\
> +	for (pos = list_entry((head)->next, typeof(*pos), member),	\
> +		n = list_entry(pos->member.next, typeof(*pos), member);	\
> +	     &pos->member != (head);					\
> +	     pos = n, n = list_entry(n->member.next, typeof(*n), member))
> +
> +/**
> + * list_empty - tests whether a list is empty
> + * @head: the list to test.
> + */
> +static inline int list_empty(const struct list_head *head)
> +{
> +	return head->next == head;
> +}
> +
> +/*
> + * Insert a new entry between two known consecutive entries.
> + *
> + * This is only for internal list manipulation where we know
> + * the prev/next entries already!
> + */
> +static inline void __list_add(struct list_head *_new,
> +			      struct list_head *prev,
> +			      struct list_head *next)
> +{
> +	next->prev = _new;
> +	_new->next = next;
> +	_new->prev = prev;
> +	prev->next = _new;
> +}
> +
> +/**
> + * list_add_tail - add a new entry
> + * @new: new entry to be added
> + * @head: list head to add it before
> + *
> + * Insert a new entry before the specified head.
> + * This is useful for implementing queues.
> + */
> +static inline void list_add_tail(struct list_head *_new, struct list_head *head)
> +{
> +	__list_add(_new, head->prev, head);
> +}
> +
> +/*
> + * Delete a list entry by making the prev/next entries
> + * point to each other.
> + *
> + * This is only for internal list manipulation where we know
> + * the prev/next entries already!
> + */
> +static inline void __list_del(struct list_head *prev, struct list_head *next)
> +{
> +	next->prev = prev;
> +	prev->next = next;
> +}
> +
> +#define LIST_POISON1  ((void *) 0x00100100)
> +#define LIST_POISON2  ((void *) 0x00200200)
> +/**
> + * list_del - deletes entry from list.
> + * @entry: the element to delete from the list.
> + * Note: list_empty() on entry does not return true after this, the entry is
> + * in an undefined state.
> + */
> +static inline void list_del(struct list_head *entry)
> +{
> +	__list_del(entry->prev, entry->next);
> +	entry->next = (struct list_head*)LIST_POISON1;
> +	entry->prev = (struct list_head*)LIST_POISON2;
> +}
> +#endif
> diff --git a/programmer.c b/programmer.c
> index 1b27c3c..2a5df92 100644
> --- a/programmer.c
> +++ b/programmer.c
> @@ -18,6 +18,8 @@
>   * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
>   */
>  
> +#include <malloc.h>
> +#include <string.h>
>  #include "flash.h"
>  #include "programmer.h"
>  
> @@ -114,31 +116,28 @@ int register_par_master(const struct par_master *mst,
>  }
>  
>  /* The limit of 4 is totally arbitrary. */
> -#define MASTERS_MAX 4
> -struct registered_master registered_masters[MASTERS_MAX];
> -int registered_master_count = 0;
> +LIST_HEAD(registered_masters);
>  
>  /* This function copies the struct registered_master parameter. */
> -int register_master(const struct registered_master *mst)
> +int register_master(struct registered_master *mst)
>  {
> -	if (registered_master_count >= MASTERS_MAX) {
> -		msg_perr("Tried to register more than %i master "
> -			 "interfaces.\n", MASTERS_MAX);
> -		return ERROR_FLASHROM_LIMIT;
> -	}
> -	registered_masters[registered_master_count] = *mst;
> -	registered_master_count++;
> +	struct registered_master *t;
> +
> +	t = malloc(sizeof(struct registered_master));
> +	memcpy(t, mst, sizeof(struct registered_master));
> +	list_add_tail(&t->node, &registered_masters);
>  
>  	return 0;
>  }
>  
>  enum chipbustype get_buses_supported(void)
>  {
> -	int i;
> +	struct registered_master *mst;
>  	enum chipbustype ret = BUS_NONE;
>  
> -	for (i = 0; i < registered_master_count; i++)
> -		ret |= registered_masters[i].buses_supported;
> +	list_for_each_entry(mst, &registered_masters, node) {
> +		ret |= mst->buses_supported;
> +	}
>  
>  	return ret;
>  }
> diff --git a/programmer.h b/programmer.h
> index 913522b..54d5634 100644
> --- a/programmer.h
> +++ b/programmer.h
> @@ -25,6 +25,7 @@
>  #define __PROGRAMMER_H__ 1
>  
>  #include "flash.h"	/* for chipaddr and flashctx */
> +#include "list.h"
>  
>  enum programmer {
>  #if CONFIG_INTERNAL == 1
> @@ -691,6 +692,7 @@ struct par_master {
>  };
>  int register_par_master(const struct par_master *mst, const enum chipbustype buses);
>  struct registered_master {
> +	struct list_head node;
>  	enum chipbustype buses_supported;
>  	union {
>  		struct par_master par;
> @@ -698,9 +700,8 @@ struct registered_master {
>  		struct opaque_master opaque;
>  	};
>  };
> -extern struct registered_master registered_masters[];
> -extern int registered_master_count;
> -int register_master(const struct registered_master *mst);
> +extern struct list_head registered_masters;
> +int register_master(struct registered_master *mst);
>  
>  /* serprog.c */
>  #if CONFIG_SERPROG == 1
> -- 
> 2.1.4
> 


-- 
-- 
Best regards,
  Antony Pavlov




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