1 files changed, 442 insertions, 0 deletions
diff --git a/kmod/cachepc.c b/kmod/cachepc.c
new file mode 100755
index 0000000..702cfad
--- /dev/null
+++ b/kmod/cachepc.c
@@ -0,0 +1,442 @@
+#include "cachepc.h"
+
+#include <linux/kernel.h>
+#include <linux/types.h> 
+#include <linux/slab.h>
+#include <linux/delay.h>
+#include <linux/ioctl.h>
+
+static void cl_insert(cacheline *last_cl, cacheline *new_cl);
+static void *remove_cache_set(cache_ctx *ctx, void *ptr);
+static void *remove_cache_group_set(void *ptr);
+
+static cacheline *prepare_cache_set_ds(cache_ctx *ctx, uint32_t *set, uint32_t sets_len);
+static cacheline *build_cache_ds(cache_ctx *ctx, cacheline **cacheline_ptr_arr);
+static void build_randomized_list_for_cache_set(cache_ctx *ctx, cacheline **cacheline_ptr_arr);
+static cacheline **allocate_cache_ds(cache_ctx *ctx);
+static uint16_t get_virt_cache_set(cache_ctx *ctx, void *ptr);
+static void *aligned_alloc(size_t alignment, size_t size);
+
+void
+cachepc_init_counters(void)
+{
+	uint64_t event, event_no, event_mask;
+	uint64_t reg_addr;
+
+	/* SEE: https://developer.amd.com/resources/developer-guides-manuals (PPR 17H 31H, P.166)
+	 *
+	 * performance event selection is done via 0xC001_020X with X = (0..A)[::2]
+	 * performance event reading is done viea 0XC001_020X with X = (1..B)[::2]
+	 *
+	 * 6 slots total
+	 */
+
+	reg_addr = 0xc0010200;
+	event_no = 0x70;
+	event_mask = 0xFF;
+	event = event_no | (event_mask << 8);
+	event |= (1ULL << 17); /* OS (kernel) events only */
+	event |= (1ULL << 22); /* enable performance counter */
+	event |= (1ULL << 40); /* Host events only */
+	printk(KERN_WARNING "CachePC: Initialized event %llu\n", event);
+	asm volatile ("wrmsr" : : "c"(reg_addr), "a"(event), "d"(0x00));
+
+	reg_addr = 0xc0010202;
+	event_no = 0x71;
+	event_mask = 0xFF;
+	event = event_no | (event_mask << 8); 
+	event |= (1ULL << 17); /* OS (kernel) events only */
+	event |= (1ULL << 22); /* enable performance counter */
+	event |= (1ULL << 40); /* Host events only */
+	printk(KERN_WARNING "CachePC: Initialized event %llu\n", event);
+	asm volatile ("wrmsr" : : "c"(reg_addr), "a"(event), "d"(0x00));
+
+	reg_addr = 0xc0010204;
+	event_no = 0x72;
+	event_mask = 0xFF;
+	event = event_no | (event_mask << 8); 
+	event |= (1ULL << 17); /* OS (kernel) events only */
+	event |= (1ULL << 22); /* enable performance counter */
+	event |= (1ULL << 40); /* Host events only */
+	printk(KERN_WARNING "CachePC: Initialized event %llu\n", event);
+	asm volatile ("wrmsr" : : "c"(reg_addr), "a"(event), "d"(0x00));
+
+}
+
+cache_ctx *
+cachepc_get_ctx(cache_level cache_level)
+{
+	cache_ctx *ctx;
+
+	// printk(KERN_WARNING "CachePC: Getting ctx..\n");
+       
+	ctx = kzalloc(sizeof(cache_ctx), GFP_KERNEL);
+	BUG_ON(ctx == NULL);
+
+	BUG_ON(cache_level != L1);
+	if (cache_level == L1) {
+		ctx->addressing = L1_ADDRESSING;
+		ctx->sets = L1_SETS;
+		ctx->associativity = L1_ASSOCIATIVITY;
+		ctx->access_time = L1_ACCESS_TIME;
+	} else if (cache_level == L2) {
+		ctx->addressing = L2_ADDRESSING;
+		ctx->sets = L2_SETS;
+		ctx->associativity = L2_ASSOCIATIVITY;
+		ctx->access_time = L2_ACCESS_TIME;
+	} else {
+		return NULL;
+	}
+
+	ctx->cache_level = cache_level;
+	ctx->nr_of_cachelines = ctx->sets * ctx->associativity;
+	ctx->set_size = CACHELINE_SIZE * ctx->associativity;
+	ctx->cache_size = ctx->sets * ctx->set_size;
+
+	// printk(KERN_WARNING "CachePC: Getting ctx done\n");
+
+	return ctx;
+}
+
+void
+cachepc_release_ctx(cache_ctx *ctx)
+{
+	kfree(ctx);
+}
+
+
+/*
+ * Initialises the complete cache data structure for the given context
+ */
+cacheline *
+cachepc_prepare_ds(cache_ctx *ctx)
+{
+	cacheline **cacheline_ptr_arr;
+	cacheline *cache_ds;
+
+	//printk(KERN_WARNING "CachePC: Preparing ds..\n");
+	
+       	cacheline_ptr_arr = allocate_cache_ds(ctx);
+	cache_ds = build_cache_ds(ctx, cacheline_ptr_arr);
+	kfree(cacheline_ptr_arr);
+
+	// printk(KERN_WARNING "CachePC: Preparing ds done\n");
+
+	return cache_ds;
+}
+
+void
+cachepc_release_ds(cache_ctx *ctx, cacheline *ds)
+{
+	kfree(remove_cache_set(ctx, ds));
+}
+
+cacheline *
+cachepc_prepare_victim(cache_ctx *ctx, uint32_t set)
+{
+	cacheline *victim_set, *victim_cl;
+	cacheline *curr_cl, *next_cl;
+
+	victim_set = prepare_cache_set_ds(ctx, &set, 1);
+	victim_cl = victim_set;
+
+	// Free the other lines in the same set that are not used.
+	if (ctx->addressing == PHYSICAL) {
+		curr_cl = victim_cl->next;
+		do {
+			next_cl = curr_cl->next;
+			// Here, it is ok to free them directly, as every line in the same
+			// set is from a different page anyway.
+			kfree(remove_cache_group_set(curr_cl));
+			curr_cl = next_cl;
+		} while(curr_cl != victim_cl);
+	}
+
+	return victim_cl;
+}
+
+void
+cachepc_release_victim(cache_ctx *ctx, cacheline *victim)
+{
+	kfree(remove_cache_set(ctx, victim));
+}
+
+void
+cachepc_save_msrmts(cacheline *head)
+{
+	cacheline *curr_cl;
+
+	printk(KERN_WARNING "CachePC: Updating /proc/cachepc\n");
+
+	curr_cl = head;
+	do {
+		if (IS_FIRST(curr_cl->flags)) {
+			BUG_ON(curr_cl->cache_set >= cachepc_msrmts_count);
+			cachepc_msrmts[curr_cl->cache_set] = curr_cl->count;
+		}
+
+		curr_cl = curr_cl->prev;
+	} while (curr_cl != head);
+}
+
+void
+cachepc_print_msrmts(cacheline *head)
+{
+	cacheline *curr_cl;
+
+	curr_cl = head;
+	do {
+		if (IS_FIRST(curr_cl->flags)) {
+			printk(KERN_WARNING "CachePC: Count for cache set %i: %llu\n",
+				curr_cl->cache_set, curr_cl->count);
+		}
+
+		curr_cl = curr_cl->prev;
+	} while (curr_cl != head);
+}
+
+
+cacheline *
+prepare_cache_set_ds(cache_ctx *ctx, uint32_t *sets, uint32_t sets_len)
+{
+	cacheline *cache_ds, **first_cl_in_sets, **last_cl_in_sets;
+	cacheline *to_del_cls, *curr_cl, *next_cl, *cache_set_ds;
+	uint32_t i, cache_groups_len, cache_groups_max_len;
+	uint32_t *cache_groups;
+       
+	cache_ds = cachepc_prepare_ds(ctx);
+
+	first_cl_in_sets = kzalloc(ctx->sets * sizeof(cacheline *), GFP_KERNEL);
+	BUG_ON(first_cl_in_sets == NULL);
+
+	last_cl_in_sets  = kzalloc(ctx->sets * sizeof(cacheline *), GFP_KERNEL);
+	BUG_ON(last_cl_in_sets == NULL);
+
+	// Find the cache groups that are used, so that we can delete the other ones
+	// later (to avoid memory leaks)
+	cache_groups_max_len = ctx->sets / CACHE_GROUP_SIZE;
+	cache_groups = kmalloc(cache_groups_max_len * sizeof(uint32_t), GFP_KERNEL);
+	BUG_ON(cache_groups == NULL);
+
+	cache_groups_len = 0;
+	for (i = 0; i < sets_len; ++i) {
+		if (!is_in_arr(sets[i] / CACHE_GROUP_SIZE, cache_groups, cache_groups_len)) {
+			cache_groups[cache_groups_len] = sets[i] / CACHE_GROUP_SIZE;
+			++cache_groups_len;
+		}
+	}
+
+	to_del_cls = NULL;
+	curr_cl = cache_ds;
+
+	// Extract the partial data structure for the cache sets and ensure correct freeing
+	do {
+		next_cl = curr_cl->next;
+
+		if (IS_FIRST(curr_cl->flags)) {
+			first_cl_in_sets[curr_cl->cache_set] = curr_cl;
+		}
+		if (IS_LAST(curr_cl->flags)) {
+			last_cl_in_sets[curr_cl->cache_set] = curr_cl;
+		}
+
+		if (ctx->addressing == PHYSICAL && !is_in_arr(
+			curr_cl->cache_set / CACHE_GROUP_SIZE, cache_groups, cache_groups_len))
+		{
+			// Already free all unused blocks of the cache ds for physical
+			// addressing, because we loose their refs
+			cl_insert(to_del_cls, curr_cl);
+			to_del_cls = curr_cl;
+		}
+		curr_cl = next_cl;
+
+	} while(curr_cl != cache_ds);
+
+	// Fix partial cache set ds
+	for (i = 0; i < sets_len; ++i) {
+		last_cl_in_sets[sets[i]]->next = first_cl_in_sets[sets[(i + 1) % sets_len]];
+		first_cl_in_sets[sets[(i + 1) % sets_len]]->prev = last_cl_in_sets[sets[i]];
+	}
+	cache_set_ds = first_cl_in_sets[sets[0]];
+
+	// Free unused cache lines
+	if (ctx->addressing == PHYSICAL) {
+		cachepc_release_ds(ctx, to_del_cls);
+	}
+
+	kfree(first_cl_in_sets);
+	kfree(last_cl_in_sets);
+	kfree(cache_groups);
+
+	return cache_set_ds;
+}
+
+void 
+cl_insert(cacheline *last_cl, cacheline *new_cl)
+{
+    if (last_cl == NULL) {
+        // Adding the first entry is a special case
+        new_cl->next = new_cl;
+        new_cl->prev = new_cl;
+    } else {
+        new_cl->next = last_cl->next;
+        new_cl->prev = last_cl;
+        last_cl->next->prev = new_cl;
+        last_cl->next = new_cl;
+    }
+}
+
+void *
+remove_cache_set(cache_ctx *ctx, void *ptr)
+{
+	return (void *) (((uintptr_t) ptr) & ~SET_MASK(ctx->sets));
+}
+
+void *
+remove_cache_group_set(void *ptr)
+{
+	return (void *) (((uintptr_t) ptr) & ~SET_MASK(CACHE_GROUP_SIZE));
+}
+
+
+/*
+ * Create a randomized doubly linked list with the following structure:
+ * set A <--> set B <--> ... <--> set X <--> set A
+ * where each set is one of the cache sets, in a random order.
+ * The sets are a doubly linked list of cachelines themselves:
+ * set A:
+ *  line[A + x0 * #sets] <--> line[A + x1 * #sets] <--> ...
+ * where x0, x1, ..., xD is a random permutation of 1, 2, ..., D
+ * and D = Associativity = | cache set |
+ */
+cacheline *build_cache_ds(cache_ctx *ctx, cacheline **cl_ptr_arr) {
+	cacheline **cl_ptr_arr_sorted;
+	cacheline *curr_cl, *next_cl;
+	cacheline *cache_ds;
+	uint32_t *idx_per_set;
+	uint32_t idx_curr_set, set_offset;
+	uint32_t i, j, set, set_len;
+	uint32_t *idx_map;
+
+ 	idx_per_set = kzalloc(ctx->sets * sizeof(uint32_t), GFP_KERNEL);
+	BUG_ON(idx_per_set == NULL);
+
+	cl_ptr_arr_sorted = kzalloc(ctx->nr_of_cachelines * sizeof(cacheline *), GFP_KERNEL);
+	BUG_ON(cl_ptr_arr_sorted == NULL);
+
+	set_len = ctx->associativity;
+	for (i = 0; i < ctx->nr_of_cachelines; ++i) {
+		set_offset = cl_ptr_arr[i]->cache_set * set_len;
+		idx_curr_set = idx_per_set[cl_ptr_arr[i]->cache_set];
+
+		cl_ptr_arr_sorted[set_offset + idx_curr_set] = cl_ptr_arr[i];
+		idx_per_set[cl_ptr_arr[i]->cache_set] += 1;
+	}
+
+	// Build doubly linked list for every set
+	for (set = 0; set < ctx->sets; ++set) {
+		set_offset = set * set_len;
+		build_randomized_list_for_cache_set(ctx, cl_ptr_arr_sorted + set_offset);
+	}
+
+	// Relink the sets among each other
+	idx_map = kzalloc(ctx->sets * sizeof(uint32_t), GFP_KERNEL);
+	BUG_ON(idx_map == NULL);
+
+	gen_random_indices(idx_map, ctx->sets);
+
+	curr_cl = cl_ptr_arr_sorted[idx_map[0] * set_len]->prev;
+	for (j = 0; j < ctx->sets; ++j) {
+		curr_cl->next = cl_ptr_arr_sorted[idx_map[(j + 1) % ctx->sets] * set_len];
+		next_cl = curr_cl->next->prev;
+		curr_cl->next->prev = curr_cl;
+		curr_cl = next_cl;
+	}
+
+	cache_ds = cl_ptr_arr_sorted[idx_map[0] * set_len];
+
+	kfree(cl_ptr_arr_sorted);
+	kfree(idx_per_set);
+	kfree(idx_map);
+
+	return cache_ds;
+}
+
+/*
+ * Helper function to build a randomised list of cacheline structs for a set
+ */
+void build_randomized_list_for_cache_set(cache_ctx *ctx, cacheline **cacheline_ptr_arr)
+{
+	cacheline *curr_cl;
+	uint32_t len, *idx_map;
+	uint16_t i;
+
+	len = ctx->associativity;
+	idx_map = kzalloc(len * sizeof(uint32_t), GFP_KERNEL);
+	BUG_ON(idx_map == NULL);
+
+	gen_random_indices(idx_map, len);
+
+	for (i = 0; i < len; ++i) {
+		curr_cl = cacheline_ptr_arr[idx_map[i]];
+		curr_cl->next = cacheline_ptr_arr[idx_map[(i + 1) % len]];
+		curr_cl->prev = cacheline_ptr_arr[idx_map[(len - 1 + i) % len]];
+		curr_cl->count = 0;
+
+		if (idx_map[i] == 0) {
+			curr_cl->flags = SET_FIRST(DEFAULT_FLAGS);
+			curr_cl->prev->flags = SET_LAST(DEFAULT_FLAGS);
+		} else {
+			curr_cl->flags = curr_cl->flags | DEFAULT_FLAGS;
+		}
+	}
+
+	kfree(idx_map);
+}
+
+/*
+ * Allocate a data structure that fills the complete cache, i.e. consisting
+ * of `associativity` many cache lines for each cache set.
+ */
+cacheline **
+allocate_cache_ds(cache_ctx *ctx)
+{
+	cacheline **cl_ptr_arr, *cl_arr;
+	uint32_t i;
+
+	cl_ptr_arr = kzalloc(ctx->nr_of_cachelines * sizeof(cacheline *), GFP_KERNEL);
+	BUG_ON(cl_ptr_arr == NULL);
+
+	BUG_ON(ctx->addressing != VIRTUAL);
+
+	// For virtual addressing, allocating a consecutive chunk of memory is enough
+	cl_arr = aligned_alloc(PAGE_SIZE, ctx->cache_size);
+	BUG_ON(cl_arr == NULL);
+
+	for (i = 0; i < ctx->nr_of_cachelines; ++i) {
+		cl_ptr_arr[i] = cl_arr + i;
+		cl_ptr_arr[i]->cache_set = get_virt_cache_set(ctx, cl_ptr_arr[i]);
+	}
+
+	return cl_ptr_arr;
+}
+
+uint16_t
+get_virt_cache_set(cache_ctx *ctx, void *ptr)
+{
+	return (uint16_t) ((((uintptr_t) ptr) & SET_MASK(ctx->sets)) / CACHELINE_SIZE);
+}
+
+void *
+aligned_alloc(size_t alignment, size_t size)
+{
+	void *p;
+
+	if (size % alignment != 0)
+		size = size - (size % alignment) + alignment;
+	p = kzalloc(size, GFP_KERNEL);
+	BUG_ON(((uintptr_t) p) % alignment != 0);
+
+	return p;
+}
+