Initial commit

src/generic/pgalloc.c

@@ -0,0 +1,172 @@
+/*
+ * Simple kernel memory allocator built on top of memcache
+ * implementation.
+ *
+ * Copyright (C) 2007 Bahadir Balban
+ */
+#include <l4/lib/memcache.h>
+#include <l4/lib/list.h>
+#include <l4/generic/space.h>
+#include <l4/generic/kmalloc.h>
+#include <l4/generic/pgalloc.h>
+#include <l4/generic/physmem.h>
+#include INC_GLUE(memory.h)
+
+#define	PGALLOC_PGD_CACHE		0
+#define PGALLOC_PMD_CACHE		1
+#define PGALLOC_PG_CACHE		2
+#define PGALLOC_CACHE_TOTAL		3
+
+/* The initial chunk of physical memory allocated before any pagers. */
+#define PGALLOC_INIT_GRANT		SZ_1MB
+
+/* Covers 3 main types of memory needed by the kernel. */
+struct pgalloc {
+	struct list_head cache_list[3];
+};
+static struct pgalloc pgalloc;
+
+void pgalloc_add_new_cache(struct mem_cache *cache, int cidx)
+{
+	INIT_LIST_HEAD(&cache->list);
+	BUG_ON(cidx >= PGALLOC_CACHE_TOTAL || cidx < 0);
+	list_add(&cache->list, &pgalloc.cache_list[cidx]);
+}
+
+void calc_kmem_usage_per_grant(kmem_usage_per_grant_t *params)
+{
+	/* Pmds, pgds, pages in numbers, per grant */
+	int pmds_per_task_avg = params->task_size_avg / PMD_MAP_SIZE;
+	int pmds_per_kmem_grant = params->tasks_per_kmem_grant * pmds_per_task_avg;
+	int pgds_per_kmem_grant = params->tasks_per_kmem_grant * 1;
+	int pgs_per_kmem_grant =  params->tasks_per_kmem_grant * 1;
+
+	/* Now everything in Kbs */
+	params->pmd_total = pmds_per_kmem_grant * PMD_SIZE;
+	params->pgd_total = pgds_per_kmem_grant * PGD_SIZE;
+	params->pg_total = pgs_per_kmem_grant * PAGE_SIZE;
+	params->extra = params->grant_size -
+	       		(params->pgd_total + params->pmd_total +
+			 params->pg_total);
+}
+
+int pgalloc_add_new_grant(unsigned long pfn, int npages)
+{
+	unsigned long physical = __pfn_to_addr(pfn);
+	void *virtual = (void *)phys_to_virt(physical);
+	struct mem_cache *pgd_cache, *pmd_cache, *pg_cache;
+	kmem_usage_per_grant_t params;
+
+	/* First map the whole grant */
+	add_mapping(physical, phys_to_virt(physical), __pfn_to_addr(npages),
+		    MAP_SVC_RW_FLAGS);
+
+	/* Calculate how to divide buffer into different caches */
+	params.task_size_avg = TASK_AVERAGE_SIZE;
+	params.grant_size = npages * PAGE_SIZE;
+
+	/* Calculate pools for how many tasks from this much grant */
+	params.tasks_per_kmem_grant = (__pfn(SZ_1MB) * TASKS_PER_1MB_GRANT) /
+				      __pfn(params.grant_size);
+	calc_kmem_usage_per_grant(&params);
+
+	/* Create the caches, least alignment-needing, most, then others. */
+	pmd_cache = mem_cache_init(virtual, params.pmd_total, PMD_SIZE, 1);
+	virtual += params.pmd_total;
+	pgd_cache = mem_cache_init(virtual, params.pgd_total, PGD_SIZE, 1);
+	virtual += params.pgd_total;
+	pg_cache = mem_cache_init(virtual, params.pg_total + params.extra,
+				  PAGE_SIZE, 1);
+
+	/* Add the caches */
+	pgalloc_add_new_cache(pgd_cache, PGALLOC_PGD_CACHE);
+	pgalloc_add_new_cache(pmd_cache, PGALLOC_PMD_CACHE);
+	pgalloc_add_new_cache(pg_cache, PGALLOC_PG_CACHE);
+
+	return 0;
+}
+
+void init_pgalloc(void)
+{
+	int initial_grant = PGALLOC_INIT_GRANT;
+
+	for (int i = 0; i < PGALLOC_CACHE_TOTAL; i++)
+		INIT_LIST_HEAD(&pgalloc.cache_list[i]);
+
+	/* Grant ourselves with an initial chunk of physical memory */
+	physmem.free_cur = page_align_up(physmem.free_cur);
+	set_page_map(physmem.free_cur, __pfn(initial_grant), 1);
+	pgalloc_add_new_grant(__pfn(physmem.free_cur), __pfn(initial_grant));
+	physmem.free_cur += initial_grant;
+
+	/* Activate kmalloc */
+	init_kmalloc();
+}
+
+void pgalloc_remove_cache(struct mem_cache *cache)
+{
+	list_del_init(&cache->list);
+}
+
+static inline void *pgalloc_from_cache(int cidx)
+{
+	struct mem_cache *cache, *n;
+
+	list_for_each_entry_safe(cache, n, &pgalloc.cache_list[cidx], list)
+		if (mem_cache_total_empty(cache))
+			return mem_cache_zalloc(cache);
+	return 0;
+}
+
+int kfree_to_cache(int cidx, void *virtual)
+{
+	struct mem_cache *cache, *n;
+
+	list_for_each_entry_safe(cache, n, &pgalloc.cache_list[cidx], list)
+		if (mem_cache_free(cache, virtual) == 0)
+			return 0;
+	return -1;
+}
+
+void *alloc_page(void)
+{
+	return pgalloc_from_cache(PGALLOC_PG_CACHE);
+}
+
+void *alloc_pmd(void)
+{
+	pmd_table_t *pmd;
+
+	if (!(pmd = alloc_boot_pmd()))
+		pmd = pgalloc_from_cache(PGALLOC_PMD_CACHE);
+
+	return pmd;
+}
+
+void *alloc_pgd(void)
+{
+	return pgalloc_from_cache(PGALLOC_PGD_CACHE);
+}
+
+int free_page(void *v)
+{
+	return kfree_to_cache(PGALLOC_PG_CACHE, v);
+}
+
+int free_pmd(void *v)
+{
+	return kfree_to_cache(PGALLOC_PMD_CACHE, v);
+}
+
+int free_pgd(void *v)
+{
+	return kfree_to_cache(PGALLOC_PGD_CACHE, v);
+}
+
+void *zalloc_page(void)
+{
+	void *p = alloc_page();
+	memset(p, 0, PAGE_SIZE);
+	return p;
+}
+