rename common to src

+ I keep starting to type src and wondering why autocomplete won't work,
  I guess src is just uncounciously a better name

1 files changed, 0 insertions, 587 deletions

diff --git a/common/pmem.c b/common/pmem.c
deleted file mode 100644
index 4da3f4c..0000000
--- a/common/pmem.c
+++ /dev/null
@@ -1,587 +0,0 @@
-/* SPDX-License-Identifier: copyleft-next-0.3.1 */
-/* Copyright 2021 - 2022, Kim Kuparinen < kimi.h.kuparinen@gmail.com > */
-
-/**
- * @file pmem.c
- * Physical memory subsystem. Allocates physical memory pages, with support for
- * different ordered pages, depending on the underlying architecture.
- *
- * Effectively, each page order (4096, 2M, 1G...) has a free list of bitmaps for
- * each page size. When an order runs out of free nodes, it just 'allocates' a
- * node from a higher order list, and gives out those maps. This turned out to
- * be around 50% faster than the previous method, with about half the necessary
- * code. Could still probably be cleaned up a little bit, in particular I don't
- * really care for probe_pmap() vs populate_pmap() but I suppose it's fine for
- * now.
- */
-
-#include <kmi/mem_nodes.h>
-#include <kmi/pmem.h>
-#include <kmi/dmem.h>
-#include <kmi/debug.h>
-#include <kmi/initrd.h>
-#include <kmi/string.h> /* memset */
-#include <kmi/bits.h> /* is_nset etc */
-#include <libfdt.h>
-
-/* \todo add memory page counting?
- * To make sure memory is not overcommited at clone, for example.
- */
-
-/**
- * Loop over orders in reverse, starting with highest, giving the iterator the
- * name \p iter.
- *
- * @param iter Name of iterator.
- */
-#define reverse_foreach_order(iter) \
-	for (enum mm_order iter = max_order(); iter != MM_MIN; --iter)
-
-/** Page bitmap node */
-struct mm_bmap {
-	/** How many bits this node has. This is generally the same as \c bits in
-	 * mm_bucket, but could be used for trailing nodes with some irregular
-	 * number of bits. */
-	size_t size;
-
-	/** How many pages are currently used */
-	size_t used;
-
-	/** Next node in freelist */
-	struct mm_bmap *next;
-
-	/** Previous node in freelist */
-	struct mm_bmap *prev;
-
-	/** Actual bitmap */
-	uint8_t bits[];
-};
-
-/** Bucket of bitmaps for some order of pages */
-struct mm_bucket {
-	/** How many bits per (regular) bitmap, see \c size in mm_bmap */
-	size_t bits;
-
-	/** Size in bytes of a page of this order */
-	size_t page_size;
-
-	/** Current head of freelist */
-	struct mm_bmap *head;
-
-	/** Bitmaps in contiguous array, to make populating easier. */
-	struct mm_bmap bmap[];
-};
-
-/** Physical map. */
-struct mm_pmap {
-	/** Base address of our map. Note that this should be the virtual base
-	 * address of the physical ram. */
-	pm_t base;
-	/** Buckets, one per order up to maximum order. */
-	struct mm_bucket *buckets[MM_NUM];
-};
-
-/** Static physical map address. \note If I support NUMA, this should probably not be
- * static, rather one physical map per NUMA region. */
-static struct mm_pmap *pmap = 0;
-
-/**
- * Zero out memory if \p populate is true.
- * Helper for populate_pmap(), makes it a bit more easy to follow when we're
- * just calculating the size of out physical map versus actually building it.
- *
- * @param populate Whether to write anything.
- * @param cont Where to write.
- * @param size How many bytes to write.
- * @return Address following last written byte.
- */
-static pm_t __zero_if(bool populate, pm_t cont, size_t size)
-{
-	if (populate)
-		memset((void *)cont, 0, size);
-
-	return cont + size;
-}
-
-/**
- * Get size in bytes of (regular) bitmap node in this bucket.
- *
- * @param bucket Bucket.
- * @return Size in bytes of (regular) bitmap node.
- */
-static size_t __get_set_size(struct mm_bucket *bucket)
-{
-	return sizeof(bucket->bmap[0]) + bucket->bits / 8;
-}
-
-/**
- * Get pointer to bitmap node at index \p set.
- *
- * @param bucket Bucket.
- * @param set Index of bitmap node to get.
- * @return Pointer to bitmap node.
- */
-static struct mm_bmap *__get_set(struct mm_bucket *bucket, size_t set)
-{
-	uintptr_t bmap = (uintptr_t)bucket->bmap;
-	return (struct mm_bmap *)(bmap + __get_set_size(bucket) * set);
-}
-
-/**
- * Get index from pointer to \p bmap within \p bucket.
- *
- * @param bucket Bucket.
- * @param bmap Bitmap node.
- * @return Index of \p bmap within \p bucket.
- */
-static size_t __get_set_index(struct mm_bucket *bucket, struct mm_bmap *bmap)
-{
-	size_t s = (uintptr_t)bmap - (uintptr_t)bucket->bmap;
-	return s / __get_set_size(bucket);
-}
-
-/**
- * Attach bitmap \p bmap to freelist within \p bucket.
- *
- * @param bucket Bucket.
- * @param bmap Bitmap node.
- */
-static void __attach_set(struct mm_bucket *bucket, struct mm_bmap *bmap)
-{
-	/* already attached */
-	if (bmap->next)
-		return;
-
-	bmap->next = bucket->head;
-	bucket->head = bmap;
-	if (bmap->next)
-		bmap->next->prev = bmap;
-}
-
-/**
- * Remove bitmap \p bmap from freelist within \p bucket.
- *
- * @param bucket Bucket.
- * @param bmap Bitmap node.
- */
-static void __detach_set(struct mm_bucket *bucket, struct mm_bmap *bmap)
-{
-	if (bucket->head == bmap)
-		bucket->head = bmap->next;
-
-	if (bmap->next)
-		bmap->next->prev = bmap->prev;
-
-	if (bmap->prev)
-		bmap->prev->next = bmap->next;
-}
-
-/**
- * Calculate address of page within bucket.
- *
- * @param bucket Bucket.
- * @param s Index of bitmap node.
- * @param b Bit within bitmap.
- * @return Address of corresponding page.
- */
-static pm_t __page_addr(struct mm_bucket *bucket, size_t s, size_t b)
-{
-	return pmap->base
-	       + s * bucket->page_size * bucket->bits
-	       + b * bucket->page_size;
-}
-
-/**
- * Calculate which bitmap node index and bit within bitmap an address
- * corresponds to.
- *
- * @param bucket Bucket.
- * @param a Address.
- * @param s Corresponding bitmap node index.
- * @param b Bitmap node bit index.
- */
-static void __get_bit(struct mm_bucket *bucket, pm_t a, size_t *s, size_t *b)
-{
-	a -= pmap->base;
-	size_t p = a / bucket->page_size;
-	*s = p / bucket->bits;
-	*b = p % bucket->bits;
-}
-
-void free_page(enum mm_order order, pm_t addr)
-{
-	struct mm_bucket *bucket = pmap->buckets[order];
-	if (!bucket)
-		return;
-
-	size_t set = 0, bit = 0;
-	__get_bit(bucket, addr, &set, &bit);
-
-	struct mm_bmap *bmap = __get_set(bucket, set);
-	bmap->used--;
-
-	bitmap_clear(bmap->bits, bit);
-	__attach_set(bucket, bmap);
-
-	if (bmap->used == 0) {
-		__detach_set(bucket, bmap);
-
-		if (bmap->size == order_width(order + 1))
-			free_page(order + 1, __page_addr(bucket, set, bit));
-	}
-}
-
-pm_t alloc_page(enum mm_order order)
-{
-	struct mm_bucket *bucket = pmap->buckets[order];
-	if (!bucket)
-		return 0;
-
-	struct mm_bmap *bmap = bucket->head;
-	if (!bmap) {
-		pm_t a = alloc_page(order + 1);
-		if (!a)
-			return 0;
-
-		size_t set = 0, bit = 0;
-		__get_bit(bucket, a, &set, &bit);
-
-		bmap = __get_set(bucket, set);
-		bmap->used = 0;
-		bitmap_clear_all(bmap->bits, bmap->size);
-		__attach_set(bucket, bmap);
-		return alloc_page(order);
-	}
-
-	bmap->used++;
-
-	size_t set = __get_set_index(bucket, bmap);
-	size_t bit = bitmap_find_first_unset(bmap->bits, bmap->size);
-	bitmap_set(bmap->bits, bit);
-
-	if (bmap->used == bmap->size)
-		__detach_set(bucket, bmap);
-
-	return __page_addr(bucket, set, bit);
-}
-
-void mark_used(enum mm_order order, pm_t addr)
-{
-	struct mm_bucket *bucket = pmap->buckets[order];
-	if (!bucket)
-		return;
-
-	size_t set = 0, bit = 0;
-	__get_bit(bucket, addr, &set, &bit);
-
-	struct mm_bmap *bmap = __get_set(bucket, set);
-	if (bmap->used == 0) {
-		bitmap_clear_all(bmap->bits, bmap->size);
-		__attach_set(bucket, bmap);
-		mark_used(order + 1, addr);
-	}
-
-	/* a page already in use can just be left alone. This MIGHT hide some
-	 * bugs in case two separate things overlap in memory during
-	 * initialization, but that scenario should probably be handled outside
-	 * of this function anyway. */
-	if (bitmap_is_set(bmap->bits, bit))
-		return;
-
-	bmap->used++;
-	bitmap_set(bmap->bits, bit);
-
-	if (bmap->used == bmap->size)
-		__detach_set(bucket, bmap);
-}
-
-/**
- * Helper for probing/populating a bucket.
- *
- * @param n How many pages in total to account for.
- * @todo currently may cut off some pages if \p n is larger than but not a multiple of order
- * width.
- * @param cont Where to place bucket.
- * @param order Order of bucket to populate.
- * @param first First bucket being populated. Top bucket, owns all pages to
- * start with.
- * @param populate Whether to actually write bucket to memory.
- * @return Address right after where last byte of bycket would be.
- */
-static pm_t __maybe_populate_bucket(size_t n, pm_t cont, enum mm_order order,
-                                    bool first, bool populate)
-{
-	struct mm_bucket *bucket = (struct mm_bucket *)cont;
-	/* todo max order? */
-	size_t bits = order_width(order + 1);
-	if (bits == 0)
-		bits = n;
-
-	if (populate) {
-		bucket->bits = bits;
-		bucket->page_size = order_size(order);
-		bucket->head = NULL;
-	}
-
-	size_t set_size = sizeof(struct mm_bmap) + bits / 8;
-
-	cont += sizeof(struct mm_bucket);
-
-	size_t sets = n / bits;
-	for (size_t i = 0; i < sets; ++i) {
-		struct mm_bmap *bmap = (struct mm_bmap *)cont;
-		if (populate) {
-			memset(bmap, 0, set_size);
-			bmap->size = bits;
-		}
-
-		if (first && populate)
-			__attach_set(bucket, bmap);
-
-		n -= bits;
-		cont += set_size;
-	}
-
-	if (n) {
-		struct mm_bmap *bmap = (struct mm_bmap *)cont;
-		if (populate)
-			bmap->size = n;
-
-		if (first && populate)
-			__attach_set(bucket, bmap);
-
-		cont += set_size;
-	}
-
-	return cont;
-}
-
-/**
- * Probe how many bytes the physical map would take up, optionally populate
- * empty physical map if \p populate is given.
- *
- * I realize it sounds like two
- * different functions, and that it might be a good idea to split in twine,
- * but my thinking was that using the same algorithm with a
- * flag to enable writing to memory would decrease chances that I would
- * calculate the size differently from what is actually needed. We need an
- * accurate estimate of the pmap size to know whether we can place it somewhere
- * and not overwrite something else.
- *
- * @param ram_base Address in kernel space where the physical RAM starts.
- * @param ram_size Size of RAM in bytes.
- * @param start Where to start building pmap.
- * @param populate Whether to actually write anything out to memory.
- * @return Size of pmap in bytes.
- */
-static pm_t __maybe_populate_pmap(pm_t ram_base, size_t ram_size, pm_t start,
-                                  bool populate)
-{
-	pm_t cont = start;
-
-	pmap = (struct mm_pmap *)start;
-	cont = __zero_if(populate, cont, sizeof(*pmap));
-	if (populate)
-		pmap->base = ram_base;
-
-	bool first = true;
-	reverse_foreach_order(iter) {
-		size_t num = ram_size / order_size(iter);
-		if (num == 0)
-			continue;
-
-		if (populate)
-			pmap->buckets[iter] = (struct mm_bucket *)cont;
-
-		cont = __maybe_populate_bucket(num, cont, iter, first,
-		                               populate);
-		first = false;
-	}
-
-	return cont - start;
-}
-
-pm_t populate_pmap(pm_t ram_base, size_t ram_size, pm_t start)
-{
-	return __maybe_populate_pmap(ram_base, ram_size, start, true);
-}
-
-pm_t probe_pmap(pm_t ram_base, size_t ram_size, pm_t start)
-{
-	return __maybe_populate_pmap(ram_base, ram_size, start, false);
-}
-
-/**
- * Helper function for marking area used.
- *
- * @param base Base address of area.
- * @param top Top address of top.
- */
-static void __mark_area_used(pm_t base, pm_t top)
-{
-	if (top < base) {
-		bug("top < base: %lx < %lx\n", top, base);
-		return;
-	}
-
-	size_t area_left = top - base;
-	pm_t runner = base;
-	while (area_left >= BASE_PAGE_SIZE) {
-		mark_used(BASE_PAGE, runner);
-		runner += BASE_PAGE_SIZE;
-		area_left -= BASE_PAGE_SIZE;
-	}
-
-	if (area_left != 0)
-		mark_used(BASE_PAGE, runner);
-}
-
-/**
- * Mark reserved memory region used, to avoid it getting accidentally allocated.
- *
- * @param fdt Global FDT pointer.
- */
-static void __mark_reserved_mem(void *fdt)
-{
-	int rmem_offset = fdt_path_offset(fdt, "/reserved-memory");
-	struct cell_info ci = get_cellinfo(fdt, rmem_offset);
-
-	int node = 0;
-	fdt_for_each_subnode(node, fdt, rmem_offset) {
-		uint8_t *rmem_reg =
-			(uint8_t *)fdt_getprop(fdt, node, "reg", NULL);
-
-		pm_t base = (pm_t)fdt_load_reg_addr(ci, rmem_reg, 0);
-
-		/** @todo make sure the top of a reserved memory area doesn't go
-		 * against our assumptions in FW_MAX_SIZE? */
-		pm_t top = (pm_t)fdt_load_reg_size(ci, rmem_reg, 0) + base;
-		__mark_area_used((pm_t)__va(base), (pm_t)__va(top));
-		info("marked [%lx - %lx] reserved\n",
-		     (pm_t)__va(base), (pm_t)__va(top));
-	}
-}
-
-/**
- * Read top of RAM from FDT.
- *
- * @param fdt Global FDT pointer.
- * @return Physical address of top of RAM.
- */
-static pm_t __get_ramtop(void *fdt)
-{
-	int mem_offset = fdt_path_offset(fdt, "/memory");
-	const void *mem_reg = fdt_getprop(fdt, mem_offset, "reg", NULL);
-
-	/* here we actually want the root offset because /memory itself doesn't
-	 * have children, I guess? */
-	struct cell_info ci = get_cellinfo(fdt, fdt_path_offset(fdt, "/"));
-	pm_t base = (pm_t)fdt_load_reg_addr(ci, mem_reg, 0);
-	return (pm_t)fdt_load_reg_size(ci, mem_reg, 0) + base;
-}
-
-/**
- * Read top of FDT.
- *
- * @param fdt Global FDT pointer.
- * @return Physical address of top of FDT.
- */
-static pm_t __get_fdttop(void *fdt)
-{
-	const char *b = (const char *)fdt;
-	return (pm_t)(b + fdt_totalsize(fdt));
-}
-
-/**
- * Return base of FDT.
- *
- * Technically pretty useless, but here mainly for cohesion.
- *
- * @param fdt Global FDT pointer.
- * @return \c fdt.
- */
-static pm_t __get_fdtbase(void *fdt)
-{
-	/* lol */
-	return (pm_t)fdt;
-}
-
-void init_pmem(void *fdt)
-{
-	/** @todo should I keep the info outputs? I suppose it's nice to see
-	 * if any assumption is being broken in the serial log, but in that case
-	 * I should really try adding more of them to other parts of the
-	 * codebase as well, the pmem subsystem isn't really especially complex.
-	 */
-	info("initializing pmem\n");
-
-	size_t max_order = 0;
-	size_t base_bits = 0;
-	size_t bits[NUM_ORDERS] = { 0 };
-	stat_pmem_conf(fdt, &max_order, &base_bits, bits);
-	init_mem(max_order, bits, base_bits);
-
-	pm_t ram_size = __get_ramtop(fdt) - get_ram_base();
-	pm_t ram_base = (pm_t)__va(get_ram_base());
-
-	info("using ram range [%lx - %lx]\n",
-	     ram_base, ram_base + ram_size);
-
-	/** @todo could probably improve error messages on failing to get fdt
-	 * values */
-	pm_t initrd_base = get_initrdbase(fdt);
-	pm_t initrd_top = get_initrdtop(fdt);
-	info("found initrd at [%lx - %lx]\n", initrd_base, initrd_top);
-
-	pm_t fdt_top = __get_fdttop(fdt);
-	pm_t fdt_base = __get_fdtbase(fdt);
-	info("found fdt at [%lx - %lx]\n", fdt_base, fdt_top);
-
-	/* find probably most suitable contiguous region of ram for our physical
-	 * ram map  */
-	/** @todo this really should check that there's enough space in RAM
-	 * instead of just forcing the pmap to be populated */
-	pm_t pmap_base = align_up(MAX(initrd_top, fdt_top), BASE_PAGE_SIZE);
-	info("choosing to place pmem map at %lx\n", pmap_base);
-
-	size_t probe_size = probe_pmap(ram_base, ram_size, pmap_base);
-	info("pmem map probe size returned %lu\n", probe_size);
-
-	size_t actual_size = populate_pmap(ram_base, ram_size, pmap_base);
-	info("pmem map actual size %lu\n", actual_size);
-
-	if (probe_size != actual_size) {
-		bug("probe_size (%#lx) != actual_size (%#lx)\n", probe_size,
-		    actual_size);
-	}
-
-	/* mark init stack, this should be unmapped once we get to executing
-	 * processes */
-	__mark_area_used(VM_STACK_BASE, VM_STACK_TOP);
-	info("marked stack [%lx - %lx] used\n", VM_STACK_BASE, VM_STACK_TOP);
-
-	/* mark kernel */
-	/* this could be made more explicit, I suppose. */
-	__mark_area_used(VM_KERN, VM_KERN + PM_KERN_SIZE);
-	info("marked kernel [%lx - %lx] used\n", VM_KERN,
-	     VM_KERN + PM_KERN_SIZE);
-
-	/* mark fdt and initrd */
-	__mark_area_used(initrd_base, initrd_top);
-	info("marked initrd [%lx - %lx] used\n", initrd_base, initrd_top);
-
-	__mark_area_used(fdt_base, fdt_top);
-	info("marked fdt [%lx - %lx] used\n", fdt_base, fdt_top);
-
-	/* mark pmap */
-	__mark_area_used(pmap_base, pmap_base + actual_size);
-	info("marked pmap [%lx - %lx] used\n", pmap_base,
-	     pmap_base + actual_size);
-
-	/* mark reserved mem */
-	__mark_reserved_mem(fdt);
-
-	init_mem_nodes();
-
-	init_devmem((pm_t)__pa(ram_base), (pm_t)__pa(ram_base + ram_size));
-}