1  /* SPDX-License-Identifier: GPL-2.0-only */
  2  #ifndef MEMRANGE_H_
  3  #define MEMRANGE_H_
  4  
  5  #include <device/resource.h>
  6  #include <stdbool.h>
  7  #include <stddef.h>
  8  
  9  /* A memranges structure consists of a list of range_entry(s). The structure
 10   * is exposed so that a memranges can be used on the stack if needed. */
 11  struct memranges {
 12  	struct range_entry *entries;
 13  	/* coreboot doesn't have a free() function. Therefore, keep a cache of
 14  	 * free'd entries.  */
 15  	struct range_entry *free_list;
 16  	/* Alignment(log 2) for base and end addresses of the range. */
 17  	unsigned char align;
 18  };
 19  
 20  /* Each region within a memranges structure is represented by a
 21   * range_entry structure. Use the associated range_entry_(base|end|size|tag)
 22   * functions to interrogate its properties. i.e. don't rely on one's own
 23   * interpretation of the fields. */
 24  struct range_entry {
 25  	resource_t begin;
 26  	resource_t end;
 27  	unsigned long tag;
 28  	struct range_entry *next;
 29  };
 30  
 31  /* Initialize a range_entry with inclusive beginning address and exclusive
 32   * end address along with the appropriate tag. */
 33  static inline void range_entry_init(struct range_entry *re,
 34  				resource_t incl_begin, resource_t excl_end,
 35  				unsigned long tag)
 36  {
 37  	re->begin = incl_begin;
 38  	re->end = excl_end - 1;
 39  	re->tag = tag;
 40  	re->next = NULL;
 41  }
 42  
 43  /* Return inclusive base address of memory range. */
 44  static inline resource_t range_entry_base(const struct range_entry *r)
 45  {
 46  	return r->begin;
 47  }
 48  
 49  /* Return exclusive end address of memory range. */
 50  static inline resource_t range_entry_end(const struct range_entry *r)
 51  {
 52  	return r->end + 1;
 53  }
 54  
 55  /* Return size of memory range. */
 56  static inline resource_t range_entry_size(const struct range_entry *r)
 57  {
 58  	return r->end - r->begin + 1;
 59  }
 60  
 61  static inline unsigned long range_entry_tag(const struct range_entry *r)
 62  {
 63  	return r->tag;
 64  }
 65  
 66  static inline void range_entry_update_tag(struct range_entry *r,
 67  					  unsigned long new_tag)
 68  {
 69  	r->tag = new_tag;
 70  }
 71  
 72  static inline bool memranges_is_empty(const struct memranges *ranges)
 73  {
 74  	return ranges->entries == NULL;
 75  }
 76  
 77  /* Iterate over each entry in a memranges structure. Ranges cannot
 78   * be deleted while processing each entry as the list cannot be safely
 79   * traversed after such an operation.
 80   * r - range_entry pointer.
 81   * ranges - memranges pointer */
 82  #define memranges_each_entry(r, ranges) \
 83  	for (r = (ranges)->entries; r != NULL; r = r->next)
 84  
 85  /* Initialize memranges structure providing an optional array of range_entry
 86   * to use as the free list. Additionally, it accepts an align parameter that
 87   * represents the required alignment(log 2) of addresses. */
 88  void memranges_init_empty_with_alignment(struct memranges *ranges,
 89  					 struct range_entry *free,
 90  					 size_t num_free, unsigned char align);
 91  
 92  /* Initialize and fill a memranges structure according to the
 93   * mask and match type for all memory resources. Tag each entry with the
 94   * specified type. Additionally, it accepts an align parameter that
 95   * represents the required alignment(log 2) of addresses. */
 96  void memranges_init_with_alignment(struct memranges *ranges,
 97  		    unsigned long mask, unsigned long match,
 98  		    unsigned long tag, unsigned char align);
 99  
100  /* Initialize memranges structure providing an optional array of range_entry
101   * to use as the free list. Addresses are default aligned to 4KiB(2^12). */
102  #define memranges_init_empty(__ranges, __free, __num_free)	\
103  	memranges_init_empty_with_alignment(__ranges, __free, __num_free, 12)
104  
105  /* Initialize and fill a memranges structure according to the
106   * mask and match type for all memory resources. Tag each entry with the
107   * specified type. Addresses are default aligned to 4KiB(2^12). */
108  #define memranges_init(__ranges, __mask, __match, __tag)	\
109  	memranges_init_with_alignment(__ranges, __mask, __match, __tag, 12)
110  
111  /* Clone a memrange. The new memrange has the same entries as the old one. */
112  void memranges_clone(struct memranges *newranges, struct memranges *oldranges);
113  
114  /* Remove and free all entries within the memranges structure. */
115  void memranges_teardown(struct memranges *ranges);
116  
117  /* Add memory resources that match with the corresponding mask and match.
118   * Each entry will be tagged with the provided tag. e.g.  To populate
119   * all cacheable memory resources in the range:
120   * memranges_add_resources(range, IORESOURCE_CACHEABLE,
121   *                            IORESROUCE_CACHEABLE, my_cacheable_tag); */
122  void memranges_add_resources(struct memranges *ranges,
123  			     unsigned long mask, unsigned long match,
124  			     unsigned long tag);
125  
126  /* Add memory resources that match with the corresponding mask and match but
127   * also provide filter as additional check. The filter will return non-zero
128   * to add the resource or zero to not add the resource. Each entry will be
129   * tagged with the provided tag. e.g.  To populate all cacheable memory
130   * resources in the range with a filter:
131   * memranges_add_resources_filter(range, IORESOURCE_CACHEABLE,
132   *                         IORESROUCE_CACHEABLE, my_cacheable_tag, filter); */
133  typedef int (*memrange_filter_t)(struct device *dev, struct resource *res);
134  void memranges_add_resources_filter(struct memranges *ranges,
135  				    unsigned long mask, unsigned long match,
136  				    unsigned long tag,
137  				    memrange_filter_t filter);
138  
139  /* Fill all address ranges up to limit (exclusive) not covered by an entry by
140   * inserting new entries with the provided tag. */
141  void memranges_fill_holes_up_to(struct memranges *ranges,
142  				resource_t limit, unsigned long tag);
143  
144  /* Create a hole in the range by deleting/modifying entries that overlap with
145   * the region specified by base and size. */
146  void memranges_create_hole(struct memranges *ranges,
147  			   resource_t base, resource_t size);
148  
149  /* Insert a resource to the given memranges.  All existing ranges
150   * covered by range specified by base and size will be removed before a
151   * new one is added. */
152  void memranges_insert(struct memranges *ranges,
153  		      resource_t base, resource_t size, unsigned long tag);
154  
155  /* Update all entries with old_tag to new_tag. */
156  void memranges_update_tag(struct memranges *ranges, unsigned long old_tag,
157  			  unsigned long new_tag);
158  
159  /* Returns next entry after the provided entry. NULL if r is last. */
160  struct range_entry *memranges_next_entry(struct memranges *ranges,
161  					 const struct range_entry *r);
162  
163  /* Steals memory from the available list in given ranges as per the constraints:
164   * limit    = Upper bound for the memory range to steal (Inclusive).
165   * size     = Requested size for the stolen memory.
166   * align    = Required alignment(log 2) for the starting address of the stolen memory.
167   * tag      = Use a range that matches the given tag.
168   * from_top = Steal the highest possible range.
169   *
170   * If the constraints can be satisfied, this function creates a hole in the memrange,
171   * writes the base address of that hole to stolen_base and returns true. Otherwise it returns
172   * false. */
173  bool memranges_steal(struct memranges *ranges, resource_t limit, resource_t size,
174  			unsigned char align, unsigned long tag, resource_t *stolen_base,
175  			bool from_top);
176  
177  #endif /* MEMRANGE_H_ */