src/fdt_handler.c - hafnium - Git at Google

 /*
  * Copyright 2018 Google LLC
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *     https://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 #include "hf/fdt_handler.h"

 #include "hf/boot_params.h"
 #include "hf/dlog.h"
 #include "hf/fdt.h"
 #include "hf/layout.h"
 #include "hf/mm.h"
 #include "hf/std.h"

 static uint64_t convert_number(const char *data, uint32_t size)
 {
 	union {
 		volatile uint64_t v;
 		char a[8];
 	} t;

 	switch (size) {
 	case sizeof(uint32_t):
 		return be32toh(*(uint32_t *)data);
 	case sizeof(uint64_t):
 		memcpy(t.a, data, sizeof(uint64_t));
 		return be64toh(t.v);
 	default:
 		return 0;
 	}
 }

 static bool fdt_read_number(const struct fdt_node *node, const char *name,
 			    uint64_t *value)
 {
 	const char *data;
 	uint32_t size;

 	if (!fdt_read_property(node, name, &data, &size)) {
 		return false;
 	}

 	switch (size) {
 	case sizeof(uint32_t):
 	case sizeof(uint64_t):
 		*value = convert_number(data, size);
 		break;

 	default:
 		return false;
 	}

 	return true;
 }

 static bool fdt_write_number(struct fdt_node *node, const char *name,
 			     uint64_t value)
 {
 	const char *data;
 	uint32_t size;
 	union {
 		volatile uint64_t v;
 		char a[8];
 	} t;

 	if (!fdt_read_property(node, name, &data, &size)) {
 		return false;
 	}

 	switch (size) {
 	case sizeof(uint32_t):
 		*(uint32_t *)data = be32toh(value);
 		break;

 	case sizeof(uint64_t):
 		t.v = be64toh(value);
 		memcpy((void *)data, t.a, sizeof(uint64_t));
 		break;

 	default:
 		return false;
 	}

 	return true;
 }

 /**
  * Finds the memory region where initrd is stored, and updates the fdt node
  * cursor to the node called "chosen".
  */
 bool fdt_find_initrd(struct fdt_node *n, paddr_t *begin, paddr_t *end)
 {
 	uint64_t initrd_begin;
 	uint64_t initrd_end;

 	if (!fdt_find_child(n, "chosen")) {
 		dlog("Unable to find 'chosen'\n");
 		return false;
 	}

 	if (!fdt_read_number(n, "linux,initrd-start", &initrd_begin)) {
 		dlog("Unable to read linux,initrd-start\n");
 		return false;
 	}

 	if (!fdt_read_number(n, "linux,initrd-end", &initrd_end)) {
 		dlog("Unable to read linux,initrd-end\n");
 		return false;
 	}

 	*begin = pa_init(initrd_begin);
 	*end = pa_init(initrd_end);

 	return true;
 }

 void fdt_find_memory_ranges(const struct fdt_node *root, struct boot_params *p)
 {
 	struct fdt_node n = *root;
 	const char *name;
 	uint64_t address_size;
 	uint64_t size_size;
 	uint64_t entry_size;
 	size_t mem_range_index = 0;

 	/* Get the sizes of memory range addresses and sizes. */
 	if (fdt_read_number(&n, "#address-cells", &address_size)) {
 		address_size *= sizeof(uint32_t);
 	} else {
 		address_size = sizeof(uint32_t);
 	}

 	if (fdt_read_number(&n, "#size-cells", &size_size)) {
 		size_size *= sizeof(uint32_t);
 	} else {
 		size_size = sizeof(uint32_t);
 	}

 	entry_size = address_size + size_size;

 	/* Look for nodes with the device_type set to "memory". */
 	if (!fdt_first_child(&n, &name)) {
 		return;
 	}

 	do {
 		const char *data;
 		uint32_t size;

 		if (!fdt_read_property(&n, "device_type", &data, &size) ||
 		    size != sizeof("memory") ||
 		    memcmp(data, "memory", sizeof("memory")) != 0 ||
 		    !fdt_read_property(&n, "reg", &data, &size)) {
 			continue;
 		}

 		/* Traverse all memory ranges within this node. */
 		while (size >= entry_size) {
 			uintpaddr_t addr = convert_number(data, address_size);
 			size_t len =
 				convert_number(data + address_size, size_size);

 			if (mem_range_index < MAX_MEM_RANGES) {
 				p->mem_ranges[mem_range_index].begin =
 					pa_init(addr);
 				p->mem_ranges[mem_range_index].end =
 					pa_init(addr + len);
 				++mem_range_index;
 			} else {
 				dlog("Found memory range %u in FDT but only "
 				     "%u supported, ignoring additional range "
 				     "of size %u.\n",
 				     mem_range_index, MAX_MEM_RANGES, len);
 			}

 			size -= entry_size;
 			data += entry_size;
 		}
 	} while (fdt_next_sibling(&n, &name));
 	p->mem_ranges_count = mem_range_index;

 	/* TODO: Check for "reserved-memory" nodes. */
 }

 struct fdt_header *fdt_map(paddr_t fdt_addr, struct fdt_node *n,
 			   struct mpool *ppool)
 {
 	struct fdt_header *fdt;

 	/* Map the fdt header in. */
 	fdt = mm_identity_map(fdt_addr, pa_add(fdt_addr, fdt_header_size()),
 			      MM_MODE_R, ppool);
 	if (!fdt) {
 		dlog("Unable to map FDT header.\n");
 		return NULL;
 	}

 	if (!fdt_root_node(n, fdt)) {
 		dlog("FDT failed validation.\n");
 		goto fail;
 	}

 	/* Map the rest of the fdt in. */
 	fdt = mm_identity_map(fdt_addr, pa_add(fdt_addr, fdt_total_size(fdt)),
 			      MM_MODE_R, ppool);
 	if (!fdt) {
 		dlog("Unable to map full FDT.\n");
 		goto fail;
 	}

 	return fdt;

 fail:
 	mm_unmap(fdt_addr, pa_add(fdt_addr, fdt_header_size()), ppool);
 	return NULL;
 }

 bool fdt_unmap(struct fdt_header *fdt, struct mpool *ppool)
 {
 	paddr_t fdt_addr = pa_from_va(va_from_ptr(fdt));

 	return mm_unmap(fdt_addr, pa_add(fdt_addr, fdt_total_size(fdt)), ppool);
 }

 bool fdt_patch(paddr_t fdt_addr, struct boot_params_update *p,
 	       struct mpool *ppool)
 {
 	struct fdt_header *fdt;
 	struct fdt_node n;
 	bool ret = false;
 	size_t i;

 	/* Map the fdt header in. */
 	fdt = mm_identity_map(fdt_addr, pa_add(fdt_addr, fdt_header_size()),
 			      MM_MODE_R, ppool);
 	if (!fdt) {
 		dlog("Unable to map FDT header.\n");
 		return false;
 	}

 	if (!fdt_root_node(&n, fdt)) {
 		dlog("FDT failed validation.\n");
 		goto err_unmap_fdt_header;
 	}

 	/* Map the fdt (+ a page) in r/w mode in preparation for updating it. */
 	fdt = mm_identity_map(fdt_addr,
 			      pa_add(fdt_addr, fdt_total_size(fdt) + PAGE_SIZE),
 			      MM_MODE_R | MM_MODE_W, ppool);
 	if (!fdt) {
 		dlog("Unable to map FDT in r/w mode.\n");
 		goto err_unmap_fdt_header;
 	}

 	if (!fdt_find_child(&n, "")) {
 		dlog("Unable to find FDT root node.\n");
 		goto out_unmap_fdt;
 	}

 	if (!fdt_find_child(&n, "chosen")) {
 		dlog("Unable to find 'chosen'\n");
 		goto out_unmap_fdt;
 	}

 	/* Patch FDT to point to new ramdisk. */
 	if (!fdt_write_number(&n, "linux,initrd-start",
 			      pa_addr(p->initrd_begin))) {
 		dlog("Unable to write linux,initrd-start\n");
 		goto out_unmap_fdt;
 	}

 	if (!fdt_write_number(&n, "linux,initrd-end", pa_addr(p->initrd_end))) {
 		dlog("Unable to write linux,initrd-end\n");
 		goto out_unmap_fdt;
 	}

 	/* Patch fdt to reserve primary VM memory. */
 	fdt_add_mem_reservation(fdt, pa_addr(layout_primary_begin()) & ~0xfffff,
 				0x80000);

 	/* Patch fdt to reserve memory for secondary VMs. */
 	for (i = 0; i < p->reserved_ranges_count; ++i) {
 		fdt_add_mem_reservation(
 			fdt, pa_addr(p->reserved_ranges[i].begin),
 			pa_addr(p->reserved_ranges[i].end) -
 				pa_addr(p->reserved_ranges[i].begin));
 	}

 	ret = true;

 out_unmap_fdt:
 	/* Unmap FDT. */
 	if (!mm_unmap(fdt_addr,
 		      pa_add(fdt_addr, fdt_total_size(fdt) + PAGE_SIZE),
 		      ppool)) {
 		dlog("Unable to unmap writable FDT.\n");
 		return false;
 	}
 	return ret;

 err_unmap_fdt_header:
 	mm_unmap(fdt_addr, pa_add(fdt_addr, fdt_header_size()), ppool);
 	return false;
 }
	/*
	* Copyright 2018 Google LLC
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* https://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	#include "hf/fdt_handler.h"

	#include "hf/boot_params.h"
	#include "hf/dlog.h"
	#include "hf/fdt.h"
	#include "hf/layout.h"
	#include "hf/mm.h"
	#include "hf/std.h"

	static uint64_t convert_number(const char *data, uint32_t size)
	{
	union {
	volatile uint64_t v;
	char a[8];
	} t;

	switch (size) {
	case sizeof(uint32_t):
	return be32toh((uint32_t )data);
	case sizeof(uint64_t):
	memcpy(t.a, data, sizeof(uint64_t));
	return be64toh(t.v);
	default:
	return 0;
	}
	}

	static bool fdt_read_number(const struct fdt_node node, const char name,
	uint64_t *value)
	{
	const char *data;
	uint32_t size;

	if (!fdt_read_property(node, name, &data, &size)) {
	return false;
	}

	switch (size) {
	case sizeof(uint32_t):
	case sizeof(uint64_t):
	*value = convert_number(data, size);
	break;

	default:
	return false;
	}

	return true;
	}

	static bool fdt_write_number(struct fdt_node node, const char name,
	uint64_t value)
	{
	const char *data;
	uint32_t size;
	union {
	volatile uint64_t v;
	char a[8];
	} t;

	if (!fdt_read_property(node, name, &data, &size)) {
	return false;
	}

	switch (size) {
	case sizeof(uint32_t):
	(uint32_t )data = be32toh(value);
	break;

	case sizeof(uint64_t):
	t.v = be64toh(value);
	memcpy((void *)data, t.a, sizeof(uint64_t));
	break;

	default:
	return false;
	}

	return true;
	}

	/**
	* Finds the memory region where initrd is stored, and updates the fdt node
	* cursor to the node called "chosen".
	*/
	bool fdt_find_initrd(struct fdt_node n, paddr_t begin, paddr_t *end)
	{
	uint64_t initrd_begin;
	uint64_t initrd_end;

	if (!fdt_find_child(n, "chosen")) {
	dlog("Unable to find 'chosen'\n");
	return false;
	}

	if (!fdt_read_number(n, "linux,initrd-start", &initrd_begin)) {
	dlog("Unable to read linux,initrd-start\n");
	return false;
	}

	if (!fdt_read_number(n, "linux,initrd-end", &initrd_end)) {
	dlog("Unable to read linux,initrd-end\n");
	return false;
	}

	*begin = pa_init(initrd_begin);
	*end = pa_init(initrd_end);

	return true;
	}

	void fdt_find_memory_ranges(const struct fdt_node root, struct boot_params p)
	{
	struct fdt_node n = *root;
	const char *name;
	uint64_t address_size;
	uint64_t size_size;
	uint64_t entry_size;
	size_t mem_range_index = 0;

	/* Get the sizes of memory range addresses and sizes. */
	if (fdt_read_number(&n, "#address-cells", &address_size)) {
	address_size *= sizeof(uint32_t);
	} else {
	address_size = sizeof(uint32_t);
	}

	if (fdt_read_number(&n, "#size-cells", &size_size)) {
	size_size *= sizeof(uint32_t);
	} else {
	size_size = sizeof(uint32_t);
	}

	entry_size = address_size + size_size;

	/* Look for nodes with the device_type set to "memory". */
	if (!fdt_first_child(&n, &name)) {
	return;
	}

	do {
	const char *data;
	uint32_t size;

	if (!fdt_read_property(&n, "device_type", &data, &size) \|\|
	size != sizeof("memory") \|\|
	memcmp(data, "memory", sizeof("memory")) != 0 \|\|
	!fdt_read_property(&n, "reg", &data, &size)) {
	continue;
	}

	/* Traverse all memory ranges within this node. */
	while (size >= entry_size) {
	uintpaddr_t addr = convert_number(data, address_size);
	size_t len =
	convert_number(data + address_size, size_size);

	if (mem_range_index < MAX_MEM_RANGES) {
	p->mem_ranges[mem_range_index].begin =
	pa_init(addr);
	p->mem_ranges[mem_range_index].end =
	pa_init(addr + len);
	++mem_range_index;
	} else {
	dlog("Found memory range %u in FDT but only "
	"%u supported, ignoring additional range "
	"of size %u.\n",
	mem_range_index, MAX_MEM_RANGES, len);
	}

	size -= entry_size;
	data += entry_size;
	}
	} while (fdt_next_sibling(&n, &name));
	p->mem_ranges_count = mem_range_index;

	/* TODO: Check for "reserved-memory" nodes. */
	}

	struct fdt_header fdt_map(paddr_t fdt_addr, struct fdt_node n,
	struct mpool *ppool)
	{
	struct fdt_header *fdt;

	/* Map the fdt header in. */
	fdt = mm_identity_map(fdt_addr, pa_add(fdt_addr, fdt_header_size()),
	MM_MODE_R, ppool);
	if (!fdt) {
	dlog("Unable to map FDT header.\n");
	return NULL;
	}

	if (!fdt_root_node(n, fdt)) {
	dlog("FDT failed validation.\n");
	goto fail;
	}

	/* Map the rest of the fdt in. */
	fdt = mm_identity_map(fdt_addr, pa_add(fdt_addr, fdt_total_size(fdt)),
	MM_MODE_R, ppool);
	if (!fdt) {
	dlog("Unable to map full FDT.\n");
	goto fail;
	}

	return fdt;

	fail:
	mm_unmap(fdt_addr, pa_add(fdt_addr, fdt_header_size()), ppool);
	return NULL;
	}

	bool fdt_unmap(struct fdt_header fdt, struct mpool ppool)
	{
	paddr_t fdt_addr = pa_from_va(va_from_ptr(fdt));

	return mm_unmap(fdt_addr, pa_add(fdt_addr, fdt_total_size(fdt)), ppool);
	}

	bool fdt_patch(paddr_t fdt_addr, struct boot_params_update *p,
	struct mpool *ppool)
	{
	struct fdt_header *fdt;
	struct fdt_node n;
	bool ret = false;
	size_t i;

	/* Map the fdt header in. */
	fdt = mm_identity_map(fdt_addr, pa_add(fdt_addr, fdt_header_size()),
	MM_MODE_R, ppool);
	if (!fdt) {
	dlog("Unable to map FDT header.\n");
	return false;
	}

	if (!fdt_root_node(&n, fdt)) {
	dlog("FDT failed validation.\n");
	goto err_unmap_fdt_header;
	}

	/* Map the fdt (+ a page) in r/w mode in preparation for updating it. */
	fdt = mm_identity_map(fdt_addr,
	pa_add(fdt_addr, fdt_total_size(fdt) + PAGE_SIZE),
	MM_MODE_R \| MM_MODE_W, ppool);
	if (!fdt) {
	dlog("Unable to map FDT in r/w mode.\n");
	goto err_unmap_fdt_header;
	}

	if (!fdt_find_child(&n, "")) {
	dlog("Unable to find FDT root node.\n");
	goto out_unmap_fdt;
	}

	if (!fdt_find_child(&n, "chosen")) {
	dlog("Unable to find 'chosen'\n");
	goto out_unmap_fdt;
	}

	/* Patch FDT to point to new ramdisk. */
	if (!fdt_write_number(&n, "linux,initrd-start",
	pa_addr(p->initrd_begin))) {
	dlog("Unable to write linux,initrd-start\n");
	goto out_unmap_fdt;
	}

	if (!fdt_write_number(&n, "linux,initrd-end", pa_addr(p->initrd_end))) {
	dlog("Unable to write linux,initrd-end\n");
	goto out_unmap_fdt;
	}

	/* Patch fdt to reserve primary VM memory. */
	fdt_add_mem_reservation(fdt, pa_addr(layout_primary_begin()) & ~0xfffff,
	0x80000);

	/* Patch fdt to reserve memory for secondary VMs. */
	for (i = 0; i < p->reserved_ranges_count; ++i) {
	fdt_add_mem_reservation(
	fdt, pa_addr(p->reserved_ranges[i].begin),
	pa_addr(p->reserved_ranges[i].end) -
	pa_addr(p->reserved_ranges[i].begin));
	}

	ret = true;

	out_unmap_fdt:
	/* Unmap FDT. */
	if (!mm_unmap(fdt_addr,
	pa_add(fdt_addr, fdt_total_size(fdt) + PAGE_SIZE),
	ppool)) {
	dlog("Unable to unmap writable FDT.\n");
	return false;
	}
	return ret;

	err_unmap_fdt_header:
	mm_unmap(fdt_addr, pa_add(fdt_addr, fdt_header_size()), ppool);
	return false;
	}