libsel4utils/src/slab.c - 3p/sel4/sel4_libs - Git at Google

 /*
  * Copyright 2017, Data61, CSIRO (ABN 41 687 119 230)
  *
  * SPDX-License-Identifier: BSD-2-Clause
  */

 #include <sel4utils/slab.h>
 #include <vka/capops.h>
 #include <vka/object.h>
 #include <utils/attribute.h>

 typedef struct {
     /* number of objects in the slab */
     seL4_CPtr n;
     /* next free object in the slab */
     seL4_CPtr next;
     /* list of objects in the slab */
     vka_object_t *objects;
 } slab_t;

 typedef struct {
     /* allocator to delegate further allocations to */
     vka_t *delegate;
     /* allocation slab of each type */
     slab_t slabs[seL4_ObjectTypeCount];
     /* untyped to allocate from */
     vka_object_t untyped;
 } slab_data_t;

 typedef struct {
     ssize_t size_bits;
     seL4_Word type;
 } object_desc_t;

 static int compare_object_descs(const void *a, const void *b)
 {
     const object_desc_t *obj_a = a;
     const object_desc_t *obj_b = b;
     /* order by biggest first */
     return obj_b->size_bits - obj_a->size_bits;
 }

 static int delegate_cspace_alloc(void *data, seL4_CPtr *res)
 {
     slab_data_t *sdata = data;
     assert(data != NULL);
     assert(sdata->delegate != NULL);
     return vka_cspace_alloc(sdata->delegate, res);
 }

 static void delegate_cspace_make_path(void *data, seL4_CPtr slot, cspacepath_t *res)
 {
     slab_data_t *sdata = data;
     vka_cspace_make_path(sdata->delegate, slot, res);
 }

 static void delegate_cspace_free(void *data, seL4_CPtr slot)
 {
     slab_data_t *sdata = data;
     vka_cspace_free(sdata->delegate, slot);
 }

 static int slab_utspace_alloc(void *data, const cspacepath_t *dest, seL4_Word type,
         seL4_Word size_bits, seL4_Word *res)
 {
     slab_data_t *sdata = data;

     if (type >= seL4_ObjectTypeCount) {
         return -1;
     }

     slab_t *slab = &sdata->slabs[type];
     if (slab->next == slab->n) {
         ZF_LOGW("Slab of type %lu expired, using delegate allocator", type);
         return vka_utspace_alloc(sdata->delegate, dest, type, size_bits, res);
     }

     cspacepath_t src;
     vka_cspace_make_path(sdata->delegate, slab->objects[slab->next].cptr, &src);
     if (vka_cnode_move(dest, &src) != seL4_NoError) {
         ZF_LOGW("Dest invalid\n");
         return -1;
     }

     slab->next++;
     return 0;
 }

 static int slab_utspace_alloc_maybe_device(void *data, const cspacepath_t *dest, seL4_Word type,
                                            seL4_Word size_bits, bool can_use_dev, seL4_Word *res)
 {
     return slab_utspace_alloc(data, dest, type, size_bits, res);
 }

 static int delegate_utspace_alloc_at(void *data, const cspacepath_t *dest, seL4_Word type, seL4_Word size_bits,
                                      uintptr_t paddr, seL4_Word *res)
 {
     slab_data_t *sdata = data;
     return vka_utspace_alloc_at(sdata->delegate, dest, type, size_bits, paddr, res);
 }

 static void
 slab_utspace_free(void *data, seL4_Word type, seL4_Word size_bits, seL4_Word target)
 {
     //TODO this should be possible - swap the object in at next, but do we need it?
     ZF_LOGW("slab_utspace_free not implemented");
 }

 static size_t calculate_total_size(size_t object_freq[seL4_ObjectTypeCount]) {
     size_t total_size = 0;
     for (int i = 0; i < seL4_ObjectTypeCount; i++) {
         if (object_freq[i] > 0) {
             size_t object_size = vka_get_object_size(i, 0);
             if (object_size == 0 || object_size == -1) {
                 ZF_LOGE("Object of undetermined size passed to slab allocator");
                 return 0;
             }
             total_size += (BIT(object_size)) * object_freq[i];
         }
     }
     return total_size;
 }

 static void slab_destroy(vka_t *slab)
 {
     ZF_LOGW("Slab destroy not implemented");
 }

 static seL4_Error alloc_object(vka_t *delegate, vka_object_t *untyped, size_t size_bits, seL4_Word type,
                                vka_object_t *object)
 {
     /* allocate slot for object */
     object->type = type;
     object->size_bits = size_bits;
     seL4_Error error = vka_cspace_alloc(delegate, &object->cptr);
     if (error != seL4_NoError) {
         ZF_LOGE("Failed to allocate cslot");
         return error;
     }

     /* convert to cspacepath */
     cspacepath_t path;
     vka_cspace_make_path(delegate, object->cptr, &path);

     /* retype object */
     return seL4_Untyped_Retype(untyped->cptr, type, size_bits, path.root, path.dest,
                                         path.destDepth, path.offset, 1);
 }

 static int alloc_object_slab(vka_t *delegate, vka_object_t *untyped, slab_t *slab, size_t n,
                              size_t size_bits, seL4_Word type)
 {
     ZF_LOGI("Preallocating %zu objects of %zu size bits, %lu type\n", n, size_bits, (long) type);

     slab->n = n;
     slab->next = 0;

     if (n > 0) {
         slab->objects = calloc(n, sizeof(vka_object_t));
         if (slab->objects == NULL) {
             ZF_LOGI("Failed to allocate %zu objects of %zu size bits, %lu type", n, size_bits, (long) type);
             return -1;
         }
     }

     for (int i = 0; i < slab->n; i++) {
         if (alloc_object(delegate, untyped, size_bits, type, &slab->objects[i]) != seL4_NoError) {
             return -1;
         }
     }

     /* success */
     return 0;
 }

 int slab_init(vka_t *slab_vka, vka_t *delegate, size_t object_freq[seL4_ObjectTypeCount]) {

     slab_data_t *data = calloc(1, sizeof(slab_data_t));

     if (!data) {
         slab_destroy(slab_vka);
         return -1;
     }

     slab_vka->data = data;
     data->delegate = delegate;

     slab_vka->cspace_alloc = delegate_cspace_alloc;
     slab_vka->cspace_make_path = delegate_cspace_make_path;
     slab_vka->cspace_free = delegate_cspace_free;
     slab_vka->utspace_alloc_at = delegate_utspace_alloc_at;
     slab_vka->utspace_alloc = slab_utspace_alloc;
     slab_vka->utspace_alloc_maybe_device = slab_utspace_alloc_maybe_device;
     slab_vka->utspace_free = slab_utspace_free;

     /* allocate untyped */
     size_t total_size = calculate_total_size(object_freq);
     size_t total_size_bits = seL4_WordBits - CLZL(total_size);
     /* sanity */
     assert(BIT(total_size_bits) >= total_size);
     if (total_size == 0) {
         ZF_LOGW("No objects to allocate\n");
         return 0;
     }

     int error = vka_alloc_untyped(delegate, total_size_bits, &data->untyped);
     if (error != 0) {
         ZF_LOGE("Failed to allocate untyped of size bits %zu\n", total_size_bits);
         slab_destroy(slab_vka);
         return -1;
     }

     /* order object sizes by size */
     object_desc_t object_descs[seL4_ObjectTypeCount];
     for (int i = 0; i < seL4_ObjectTypeCount; i++) {
         object_descs[i].type = i;
         object_descs[i].size_bits = vka_get_object_size(i, 0);
     }

     qsort(object_descs, seL4_ObjectTypeCount, sizeof(object_desc_t), compare_object_descs);

     /* allocate slabs */
     for (int i = 0; i < seL4_ObjectTypeCount && object_descs[i].size_bits != 0; i++) {
         int type = object_descs[i].type;
         error = alloc_object_slab(delegate, &data->untyped, &data->slabs[type],
                                   object_freq[type], object_descs[i].size_bits, type);
         if (error != 0) {
             ZF_LOGE("Failed to create slab\n");
             slab_destroy(slab_vka);
             return -1;
         }
     }

     return 0;
 }
	/*
	* Copyright 2017, Data61, CSIRO (ABN 41 687 119 230)
	*
	* SPDX-License-Identifier: BSD-2-Clause
	*/

	#include <sel4utils/slab.h>
	#include <vka/capops.h>
	#include <vka/object.h>
	#include <utils/attribute.h>

	typedef struct {
	/* number of objects in the slab */
	seL4_CPtr n;
	/* next free object in the slab */
	seL4_CPtr next;
	/* list of objects in the slab */
	vka_object_t *objects;
	} slab_t;

	typedef struct {
	/* allocator to delegate further allocations to */
	vka_t *delegate;
	/* allocation slab of each type */
	slab_t slabs[seL4_ObjectTypeCount];
	/* untyped to allocate from */
	vka_object_t untyped;
	} slab_data_t;

	typedef struct {
	ssize_t size_bits;
	seL4_Word type;
	} object_desc_t;

	static int compare_object_descs(const void a, const void b)
	{
	const object_desc_t *obj_a = a;
	const object_desc_t *obj_b = b;
	/* order by biggest first */
	return obj_b->size_bits - obj_a->size_bits;
	}

	static int delegate_cspace_alloc(void data, seL4_CPtr res)
	{
	slab_data_t *sdata = data;
	assert(data != NULL);
	assert(sdata->delegate != NULL);
	return vka_cspace_alloc(sdata->delegate, res);
	}

	static void delegate_cspace_make_path(void data, seL4_CPtr slot, cspacepath_t res)
	{
	slab_data_t *sdata = data;
	vka_cspace_make_path(sdata->delegate, slot, res);
	}

	static void delegate_cspace_free(void *data, seL4_CPtr slot)
	{
	slab_data_t *sdata = data;
	vka_cspace_free(sdata->delegate, slot);
	}

	static int slab_utspace_alloc(void data, const cspacepath_t dest, seL4_Word type,
	seL4_Word size_bits, seL4_Word *res)
	{
	slab_data_t *sdata = data;

	if (type >= seL4_ObjectTypeCount) {
	return -1;
	}

	slab_t *slab = &sdata->slabs[type];
	if (slab->next == slab->n) {
	ZF_LOGW("Slab of type %lu expired, using delegate allocator", type);
	return vka_utspace_alloc(sdata->delegate, dest, type, size_bits, res);
	}

	cspacepath_t src;
	vka_cspace_make_path(sdata->delegate, slab->objects[slab->next].cptr, &src);
	if (vka_cnode_move(dest, &src) != seL4_NoError) {
	ZF_LOGW("Dest invalid\n");
	return -1;
	}

	slab->next++;
	return 0;
	}

	static int slab_utspace_alloc_maybe_device(void data, const cspacepath_t dest, seL4_Word type,
	seL4_Word size_bits, bool can_use_dev, seL4_Word *res)
	{
	return slab_utspace_alloc(data, dest, type, size_bits, res);
	}

	static int delegate_utspace_alloc_at(void data, const cspacepath_t dest, seL4_Word type, seL4_Word size_bits,
	uintptr_t paddr, seL4_Word *res)
	{
	slab_data_t *sdata = data;
	return vka_utspace_alloc_at(sdata->delegate, dest, type, size_bits, paddr, res);
	}

	static void
	slab_utspace_free(void *data, seL4_Word type, seL4_Word size_bits, seL4_Word target)
	{
	//TODO this should be possible - swap the object in at next, but do we need it?
	ZF_LOGW("slab_utspace_free not implemented");
	}

	static size_t calculate_total_size(size_t object_freq[seL4_ObjectTypeCount]) {
	size_t total_size = 0;
	for (int i = 0; i < seL4_ObjectTypeCount; i++) {
	if (object_freq[i] > 0) {
	size_t object_size = vka_get_object_size(i, 0);
	if (object_size == 0 \|\| object_size == -1) {
	ZF_LOGE("Object of undetermined size passed to slab allocator");
	return 0;
	}
	total_size += (BIT(object_size)) * object_freq[i];
	}
	}
	return total_size;
	}

	static void slab_destroy(vka_t *slab)
	{
	ZF_LOGW("Slab destroy not implemented");
	}

	static seL4_Error alloc_object(vka_t delegate, vka_object_t untyped, size_t size_bits, seL4_Word type,
	vka_object_t *object)
	{
	/* allocate slot for object */
	object->type = type;
	object->size_bits = size_bits;
	seL4_Error error = vka_cspace_alloc(delegate, &object->cptr);
	if (error != seL4_NoError) {
	ZF_LOGE("Failed to allocate cslot");
	return error;
	}

	/* convert to cspacepath */
	cspacepath_t path;
	vka_cspace_make_path(delegate, object->cptr, &path);

	/* retype object */
	return seL4_Untyped_Retype(untyped->cptr, type, size_bits, path.root, path.dest,
	path.destDepth, path.offset, 1);
	}

	static int alloc_object_slab(vka_t delegate, vka_object_t untyped, slab_t *slab, size_t n,
	size_t size_bits, seL4_Word type)
	{
	ZF_LOGI("Preallocating %zu objects of %zu size bits, %lu type\n", n, size_bits, (long) type);

	slab->n = n;
	slab->next = 0;

	if (n > 0) {
	slab->objects = calloc(n, sizeof(vka_object_t));
	if (slab->objects == NULL) {
	ZF_LOGI("Failed to allocate %zu objects of %zu size bits, %lu type", n, size_bits, (long) type);
	return -1;
	}
	}

	for (int i = 0; i < slab->n; i++) {
	if (alloc_object(delegate, untyped, size_bits, type, &slab->objects[i]) != seL4_NoError) {
	return -1;
	}
	}

	/* success */
	return 0;
	}

	int slab_init(vka_t slab_vka, vka_t delegate, size_t object_freq[seL4_ObjectTypeCount]) {

	slab_data_t *data = calloc(1, sizeof(slab_data_t));

	if (!data) {
	slab_destroy(slab_vka);
	return -1;
	}

	slab_vka->data = data;
	data->delegate = delegate;

	slab_vka->cspace_alloc = delegate_cspace_alloc;
	slab_vka->cspace_make_path = delegate_cspace_make_path;
	slab_vka->cspace_free = delegate_cspace_free;
	slab_vka->utspace_alloc_at = delegate_utspace_alloc_at;
	slab_vka->utspace_alloc = slab_utspace_alloc;
	slab_vka->utspace_alloc_maybe_device = slab_utspace_alloc_maybe_device;
	slab_vka->utspace_free = slab_utspace_free;

	/* allocate untyped */
	size_t total_size = calculate_total_size(object_freq);
	size_t total_size_bits = seL4_WordBits - CLZL(total_size);
	/* sanity */
	assert(BIT(total_size_bits) >= total_size);
	if (total_size == 0) {
	ZF_LOGW("No objects to allocate\n");
	return 0;
	}

	int error = vka_alloc_untyped(delegate, total_size_bits, &data->untyped);
	if (error != 0) {
	ZF_LOGE("Failed to allocate untyped of size bits %zu\n", total_size_bits);
	slab_destroy(slab_vka);
	return -1;
	}

	/* order object sizes by size */
	object_desc_t object_descs[seL4_ObjectTypeCount];
	for (int i = 0; i < seL4_ObjectTypeCount; i++) {
	object_descs[i].type = i;
	object_descs[i].size_bits = vka_get_object_size(i, 0);
	}

	qsort(object_descs, seL4_ObjectTypeCount, sizeof(object_desc_t), compare_object_descs);

	/* allocate slabs */
	for (int i = 0; i < seL4_ObjectTypeCount && object_descs[i].size_bits != 0; i++) {
	int type = object_descs[i].type;
	error = alloc_object_slab(delegate, &data->untyped, &data->slabs[type],
	object_freq[type], object_descs[i].size_bits, type);
	if (error != 0) {
	ZF_LOGE("Failed to create slab\n");
	slab_destroy(slab_vka);
	return -1;
	}
	}

	return 0;
	}