Port liballoc to userspace

libmsl/alloc/.gitignore

@@ -0,0 +1 @@
+*.o

libmsl/alloc/liballoc.c

@@ -0,0 +1,406 @@
+/* liballoc breaks when optimized too aggressively, for eg. clang's -Oz */
+#pragma clang optimize off
+
+#include <alloc/liballoc.h>
+#include <m/proc.h>
+
+static int liballoc_mutex;
+static uintptr_t liballoc_map_base = PROC_MAP_BASE;
+static int mem_rid_base = 10000;
+
+void liballoc_init (void) { liballoc_mutex = proc_create_resource_mutex (100, RV_PRIVATE); }
+
+int liballoc_lock (void) {
+  proc_mutex_lock (liballoc_mutex);
+  return 0;
+}
+
+int liballoc_unlock (void) {
+  proc_mutex_unlock (liballoc_mutex);
+  return 0;
+}
+
+void* liballoc_alloc (int pages) {
+  uintptr_t current_base = liballoc_map_base;
+  uintptr_t out_paddr;
+
+  int mem_rid = proc_create_resource_mem (mem_rid_base++, pages, RV_PRIVATE, &out_paddr);
+  if (mem_rid < 0)
+    return NULL;
+
+  proc_map (out_paddr, current_base, pages, PM_PRESENT | PM_RW | PM_USER);
+
+  uintptr_t old_base = current_base;
+  current_base += pages * PAGE_SIZE;
+
+  return (void*)old_base;
+}
+
+int liballoc_free (void* ptr, int pages) { return 0; }
+
+/**  Durand's Ridiculously Amazing Super Duper Memory functions.  */
+
+// #define DEBUG
+
+#define LIBALLOC_MAGIC 0xc001c0de
+#define MAXCOMPLETE    5
+#define MAXEXP         32
+#define MINEXP         8
+
+#define MODE_BEST    0
+#define MODE_INSTANT 1
+
+#define MODE MODE_BEST
+
+struct boundary_tag* l_freePages[MAXEXP]; //< Allowing for 2^MAXEXP blocks
+int l_completePages[MAXEXP];              //< Allowing for 2^MAXEXP blocks
+
+static int l_initialized = 0;      //< Flag to indicate initialization.
+static int l_pageSize = PAGE_SIZE; //< Individual page size
+static int l_pageCount = 16;       //< Minimum number of pages to allocate.
+
+// ***********   HELPER FUNCTIONS  *******************************
+
+/** Returns the exponent required to manage 'size' amount of memory.
+ *
+ *  Returns n where  2^n <= size < 2^(n+1)
+ */
+static inline int getexp (unsigned int size) {
+  if (size < (1 << MINEXP)) {
+    return -1; // Smaller than the quantum.
+  }
+
+  int shift = MINEXP;
+
+  while (shift < MAXEXP) {
+    if ((1 << shift) > size)
+      break;
+    shift += 1;
+  }
+
+  return shift - 1;
+}
+
+static void* liballoc_memset (void* s, int c, size_t n) {
+  size_t i;
+  for (i = 0; i < n; i++)
+    ((char*)s)[i] = c;
+
+  return s;
+}
+
+static void* liballoc_memcpy (void* s1, const void* s2, size_t n) {
+  char* cdest;
+  char* csrc;
+  unsigned int* ldest = (unsigned int*)s1;
+  unsigned int* lsrc = (unsigned int*)s2;
+
+  while (n >= sizeof (unsigned int)) {
+    *ldest++ = *lsrc++;
+    n -= sizeof (unsigned int);
+  }
+
+  cdest = (char*)ldest;
+  csrc = (char*)lsrc;
+
+  while (n > 0) {
+    *cdest++ = *csrc++;
+    n -= 1;
+  }
+
+  return s1;
+}
+
+static inline void insert_tag (struct boundary_tag* tag, int index) {
+  int realIndex;
+
+  if (index < 0) {
+    realIndex = getexp (tag->real_size - sizeof (struct boundary_tag));
+    if (realIndex < MINEXP)
+      realIndex = MINEXP;
+  } else
+    realIndex = index;
+
+  tag->index = realIndex;
+
+  if (l_freePages[realIndex] != NULL) {
+    l_freePages[realIndex]->prev = tag;
+    tag->next = l_freePages[realIndex];
+  }
+
+  l_freePages[realIndex] = tag;
+}
+
+static inline void remove_tag (struct boundary_tag* tag) {
+  if (l_freePages[tag->index] == tag)
+    l_freePages[tag->index] = tag->next;
+
+  if (tag->prev != NULL)
+    tag->prev->next = tag->next;
+  if (tag->next != NULL)
+    tag->next->prev = tag->prev;
+
+  tag->next = NULL;
+  tag->prev = NULL;
+  tag->index = -1;
+}
+
+static inline struct boundary_tag* melt_left (struct boundary_tag* tag) {
+  struct boundary_tag* left = tag->split_left;
+
+  left->real_size += tag->real_size;
+  left->split_right = tag->split_right;
+
+  if (tag->split_right != NULL)
+    tag->split_right->split_left = left;
+
+  return left;
+}
+
+static inline struct boundary_tag* absorb_right (struct boundary_tag* tag) {
+  struct boundary_tag* right = tag->split_right;
+
+  remove_tag (right); // Remove right from free pages.
+
+  tag->real_size += right->real_size;
+
+  tag->split_right = right->split_right;
+  if (right->split_right != NULL)
+    right->split_right->split_left = tag;
+
+  return tag;
+}
+
+static inline struct boundary_tag* split_tag (struct boundary_tag* tag) {
+  unsigned int remainder = tag->real_size - sizeof (struct boundary_tag) - tag->size;
+
+  struct boundary_tag* new_tag =
+      (struct boundary_tag*)((uintptr_t)tag + sizeof (struct boundary_tag) + tag->size);
+
+  new_tag->magic = LIBALLOC_MAGIC;
+  new_tag->real_size = remainder;
+
+  new_tag->next = NULL;
+  new_tag->prev = NULL;
+
+  new_tag->split_left = tag;
+  new_tag->split_right = tag->split_right;
+
+  if (new_tag->split_right != NULL)
+    new_tag->split_right->split_left = new_tag;
+  tag->split_right = new_tag;
+
+  tag->real_size -= new_tag->real_size;
+
+  insert_tag (new_tag, -1);
+
+  return new_tag;
+}
+
+// ***************************************************************
+
+static struct boundary_tag* allocate_new_tag (unsigned int size) {
+  unsigned int pages;
+  unsigned int usage;
+  struct boundary_tag* tag;
+
+  // This is how much space is required.
+  usage = size + sizeof (struct boundary_tag);
+
+  // Perfect amount of space
+  pages = usage / l_pageSize;
+  if ((usage % l_pageSize) != 0)
+    pages += 1;
+
+  // Make sure it's >= the minimum size.
+  if (pages < (unsigned int)l_pageCount)
+    pages = l_pageCount;
+
+  tag = (struct boundary_tag*)liballoc_alloc (pages);
+
+  if (tag == NULL)
+    return NULL; // uh oh, we ran out of memory.
+
+  tag->magic = LIBALLOC_MAGIC;
+  tag->size = size;
+  tag->real_size = pages * l_pageSize;
+  tag->index = -1;
+
+  tag->next = NULL;
+  tag->prev = NULL;
+  tag->split_left = NULL;
+  tag->split_right = NULL;
+
+  return tag;
+}
+
+void* malloc (size_t size) {
+  int index;
+  void* ptr;
+  struct boundary_tag* tag = NULL;
+
+  liballoc_lock ();
+
+  if (l_initialized == 0) {
+    for (index = 0; index < MAXEXP; index++) {
+      l_freePages[index] = NULL;
+      l_completePages[index] = 0;
+    }
+    l_initialized = 1;
+  }
+
+  index = getexp (size) + MODE;
+  if (index < MINEXP)
+    index = MINEXP;
+
+  // Find one big enough.
+  tag = l_freePages[index]; // Start at the front of the list.
+  while (tag != NULL) {
+    // If there's enough space in this tag.
+    if ((tag->real_size - sizeof (struct boundary_tag)) >= (size + sizeof (struct boundary_tag))) {
+      break;
+    }
+
+    tag = tag->next;
+  }
+
+  // No page found. Make one.
+  if (tag == NULL) {
+    if ((tag = allocate_new_tag (size)) == NULL) {
+      liballoc_unlock ();
+      return NULL;
+    }
+
+    index = getexp (tag->real_size - sizeof (struct boundary_tag));
+  } else {
+    remove_tag (tag);
+
+    if ((tag->split_left == NULL) && (tag->split_right == NULL))
+      l_completePages[index] -= 1;
+  }
+
+  // We have a free page.  Remove it from the free pages list.
+
+  tag->size = size;
+
+  // Removed... see if we can re-use the excess space.
+
+  unsigned int remainder =
+      tag->real_size - size - sizeof (struct boundary_tag) * 2; // Support a new tag + remainder
+
+  if (((int)(remainder) > 0) /*&& ( (tag->real_size - remainder) >= (1<<MINEXP))*/) {
+    int childIndex = getexp (remainder);
+
+    if (childIndex >= 0) {
+      struct boundary_tag* new_tag = split_tag (tag);
+
+      (void)new_tag;
+    }
+  }
+
+  ptr = (void*)((uintptr_t)tag + sizeof (struct boundary_tag));
+
+  liballoc_unlock ();
+  return ptr;
+}
+
+void free (void* ptr) {
+  int index;
+  struct boundary_tag* tag;
+
+  if (ptr == NULL)
+    return;
+
+  liballoc_lock ();
+
+  tag = (struct boundary_tag*)((uintptr_t)ptr - sizeof (struct boundary_tag));
+
+  if (tag->magic != LIBALLOC_MAGIC) {
+    liballoc_unlock (); // release the lock
+    return;
+  }
+
+  // MELT LEFT...
+  while ((tag->split_left != NULL) && (tag->split_left->index >= 0)) {
+    tag = melt_left (tag);
+    remove_tag (tag);
+  }
+
+  // MELT RIGHT...
+  while ((tag->split_right != NULL) && (tag->split_right->index >= 0)) {
+    tag = absorb_right (tag);
+  }
+
+  // Where is it going back to?
+  index = getexp (tag->real_size - sizeof (struct boundary_tag));
+  if (index < MINEXP)
+    index = MINEXP;
+
+  // A whole, empty block?
+  if ((tag->split_left == NULL) && (tag->split_right == NULL)) {
+    if (l_completePages[index] == MAXCOMPLETE) {
+      // Too many standing by to keep. Free this one.
+      unsigned int pages = tag->real_size / l_pageSize;
+
+      if ((tag->real_size % l_pageSize) != 0)
+        pages += 1;
+      if (pages < (unsigned int)l_pageCount)
+        pages = l_pageCount;
+
+      liballoc_free (tag, pages);
+
+      liballoc_unlock ();
+      return;
+    }
+
+    l_completePages[index] += 1; // Increase the count of complete pages.
+  }
+
+  // ..........
+
+  insert_tag (tag, index);
+
+  liballoc_unlock ();
+}
+
+void* calloc (size_t nobj, size_t size) {
+  int real_size;
+  void* p;
+
+  real_size = nobj * size;
+
+  p = malloc (real_size);
+
+  liballoc_memset (p, 0, real_size);
+
+  return p;
+}
+
+void* realloc (void* p, size_t size) {
+  void* ptr;
+  struct boundary_tag* tag;
+  int real_size;
+
+  if (size == 0) {
+    free (p);
+    return NULL;
+  }
+  if (p == NULL)
+    return malloc (size);
+
+  if (&liballoc_lock != NULL)
+    liballoc_lock (); // lockit
+  tag = (struct boundary_tag*)((uintptr_t)p - sizeof (struct boundary_tag));
+  real_size = tag->size;
+  if (&liballoc_unlock != NULL)
+    liballoc_unlock ();
+
+  if ((size_t)real_size > size)
+    real_size = size;
+
+  ptr = malloc (size);
+  liballoc_memcpy (ptr, p, real_size);
+  free (p);
+
+  return ptr;
+}

libmsl/alloc/liballoc.h

@@ -0,0 +1,93 @@
+#ifndef _LIBALLOC_H
+#define _LIBALLOC_H
+
+#include <stddef.h>
+#include <stdint.h>
+
+#define _ALLOC_SKIP_DEFINE
+
+// If we are told to not define our own size_t, then we
+// skip the define.
+#ifndef _ALLOC_SKIP_DEFINE
+
+#ifndef _HAVE_SIZE_T
+#define _HAVE_SIZE_T
+typedef unsigned int size_t;
+#endif
+
+#ifndef NULL
+#define NULL 0
+#endif
+
+#endif
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/** This is a boundary tag which is prepended to the
+ * page or section of a page which we have allocated. It is
+ * used to identify valid memory blocks that the
+ * application is trying to free.
+ */
+struct boundary_tag {
+  unsigned int magic;     //< It's a kind of ...
+  unsigned int size;      //< Requested size.
+  unsigned int real_size; //< Actual size.
+  int index;              //< Location in the page table.
+
+  struct boundary_tag* split_left;  //< Linked-list info for broken pages.
+  struct boundary_tag* split_right; //< The same.
+
+  struct boundary_tag* next; //< Linked list info.
+  struct boundary_tag* prev; //< Linked list info.
+};
+
+/** This function is supposed to lock the memory data structures. It
+ * could be as simple as disabling interrupts or acquiring a spinlock.
+ * It's up to you to decide.
+ *
+ * \return 0 if the lock was acquired successfully. Anything else is
+ * failure.
+ */
+extern int liballoc_lock (void);
+
+/** This function unlocks what was previously locked by the liballoc_lock
+ * function.  If it disabled interrupts, it enables interrupts. If it
+ * had acquiried a spinlock, it releases the spinlock. etc.
+ *
+ * \return 0 if the lock was successfully released.
+ */
+extern int liballoc_unlock (void);
+
+/** This is the hook into the local system which allocates pages. It
+ * accepts an integer parameter which is the number of pages
+ * required.  The page size was set up in the liballoc_init function.
+ *
+ * \return NULL if the pages were not allocated.
+ * \return A pointer to the allocated memory.
+ */
+extern void* liballoc_alloc (int);
+
+/** This frees previously allocated memory. The void* parameter passed
+ * to the function is the exact same value returned from a previous
+ * liballoc_alloc call.
+ *
+ * The integer value is the number of pages to free.
+ *
+ * \return 0 if the memory was successfully freed.
+ */
+extern int liballoc_free (void*, int);
+
+void* malloc (size_t);         //< The standard function.
+void* realloc (void*, size_t); //< The standard function.
+void* calloc (size_t, size_t); //< The standard function.
+void free (void*);             //< The standard function.
+
+void liballoc_init (void);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif

libmsl/alloc/src.mk

@@ -0,0 +1,3 @@
+c += alloc/liballoc.c
+
+o += alloc/liballoc.o