hw/nvram/xlnx-efuse.c - qemu - Git at Google

 /*
  * QEMU model of the EFUSE eFuse
  *
  * Copyright (c) 2015 Xilinx Inc.
  *
  * Written by Edgar E. Iglesias <edgari@xilinx.com>
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
  * in the Software without restriction, including without limitation the rights
  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  * copies of the Software, and to permit persons to whom the Software is
  * furnished to do so, subject to the following conditions:
  *
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
  *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */

 #include "qemu/osdep.h"
 #include "hw/nvram/xlnx-efuse.h"

 #include "qemu/error-report.h"
 #include "qemu/log.h"
 #include "qapi/error.h"
 #include "sysemu/blockdev.h"
 #include "hw/qdev-properties.h"
 #include "hw/qdev-properties-system.h"

 #define TBIT0_OFFSET     28
 #define TBIT1_OFFSET     29
 #define TBIT2_OFFSET     30
 #define TBIT3_OFFSET     31
 #define TBITS_PATTERN    (0x0AU << TBIT0_OFFSET)
 #define TBITS_MASK       (0x0FU << TBIT0_OFFSET)

 bool xlnx_efuse_get_bit(XlnxEFuse *s, unsigned int bit)
 {
     bool b = s->fuse32[bit / 32] & (1 << (bit % 32));
     return b;
 }

 static int efuse_bytes(XlnxEFuse *s)
 {
     return ROUND_UP((s->efuse_nr * s->efuse_size) / 8, 4);
 }

 static int efuse_bdrv_read(XlnxEFuse *s, Error **errp)
 {
     uint32_t *ram = s->fuse32;
     int nr = efuse_bytes(s);

     if (!s->blk) {
         return 0;
     }

     s->blk_ro = !blk_supports_write_perm(s->blk);
     if (!s->blk_ro) {
         int rc;

         rc = blk_set_perm(s->blk,
                           (BLK_PERM_CONSISTENT_READ | BLK_PERM_WRITE),
                           BLK_PERM_ALL, NULL);
         if (rc) {
             s->blk_ro = true;
         }
     }
     if (s->blk_ro) {
         warn_report("%s: Skip saving updates to read-only eFUSE backstore.",
                     blk_name(s->blk));
     }

     if (blk_pread(s->blk, 0, nr, ram, 0) < 0) {
         error_setg(errp, "%s: Failed to read %u bytes from eFUSE backstore.",
                    blk_name(s->blk), nr);
         return -1;
     }

     /* Convert from little-endian backstore for each 32-bit row */
     nr /= 4;
     while (nr--) {
         ram[nr] = le32_to_cpu(ram[nr]);
     }

     return 0;
 }

 static void efuse_bdrv_sync(XlnxEFuse *s, unsigned int bit)
 {
     unsigned int row_offset;
     uint32_t le32;

     if (!s->blk || s->blk_ro) {
         return;  /* Silent on read-only backend to avoid message flood */
     }

     /* Backstore is always in little-endian */
     le32 = cpu_to_le32(xlnx_efuse_get_row(s, bit));

     row_offset = (bit / 32) * 4;
     if (blk_pwrite(s->blk, row_offset, 4, &le32, 0) < 0) {
         error_report("%s: Failed to write offset %u of eFUSE backstore.",
                      blk_name(s->blk), row_offset);
     }
 }

 static int efuse_ro_bits_cmp(const void *a, const void *b)
 {
     uint32_t i = *(const uint32_t *)a;
     uint32_t j = *(const uint32_t *)b;

     return (i > j) - (i < j);
 }

 static void efuse_ro_bits_sort(XlnxEFuse *s)
 {
     uint32_t *ary = s->ro_bits;
     const uint32_t cnt = s->ro_bits_cnt;

     if (ary && cnt > 1) {
         qsort(ary, cnt, sizeof(ary[0]), efuse_ro_bits_cmp);
     }
 }

 static bool efuse_ro_bits_find(XlnxEFuse *s, uint32_t k)
 {
     const uint32_t *ary = s->ro_bits;
     const uint32_t cnt = s->ro_bits_cnt;

     if (!ary || !cnt) {
         return false;
     }

     return bsearch(&k, ary, cnt, sizeof(ary[0]), efuse_ro_bits_cmp) != NULL;
 }

 bool xlnx_efuse_set_bit(XlnxEFuse *s, unsigned int bit)
 {
     uint32_t set, *row;

     if (efuse_ro_bits_find(s, bit)) {
         g_autofree char *path = object_get_canonical_path(OBJECT(s));

         qemu_log_mask(LOG_GUEST_ERROR, "%s: WARN: "
                       "Ignored setting of readonly efuse bit<%u,%u>!\n",
                       path, (bit / 32), (bit % 32));
         return false;
     }

     /* Avoid back-end write unless there is a real update */
     row = &s->fuse32[bit / 32];
     set = 1 << (bit % 32);
     if (!(set & *row)) {
         *row |= set;
         efuse_bdrv_sync(s, bit);
     }
     return true;
 }

 bool xlnx_efuse_k256_check(XlnxEFuse *s, uint32_t crc, unsigned start)
 {
     uint32_t calc;

     /* A key always occupies multiple of whole rows */
     assert((start % 32) == 0);

     calc = xlnx_efuse_calc_crc(&s->fuse32[start / 32], (256 / 32), 0);
     return calc == crc;
 }

 uint32_t xlnx_efuse_tbits_check(XlnxEFuse *s)
 {
     int nr;
     uint32_t check = 0;

     for (nr = s->efuse_nr; nr-- > 0; ) {
         int efuse_start_row_num = (s->efuse_size * nr) / 32;
         uint32_t data = s->fuse32[efuse_start_row_num];

         /*
          * If the option is on, auto-init blank T-bits.
          * (non-blank will still be reported as '0' in the check, e.g.,
          *  for error-injection tests)
          */
         if ((data & TBITS_MASK) == 0 && s->init_tbits) {
             data |= TBITS_PATTERN;

             s->fuse32[efuse_start_row_num] = data;
             efuse_bdrv_sync(s, (efuse_start_row_num * 32 + TBIT0_OFFSET));
         }

         check = (check << 1) | ((data & TBITS_MASK) == TBITS_PATTERN);
     }

     return check;
 }

 static void efuse_realize(DeviceState *dev, Error **errp)
 {
     XlnxEFuse *s = XLNX_EFUSE(dev);

     /* Sort readonly-list for bsearch lookup */
     efuse_ro_bits_sort(s);

     if ((s->efuse_size % 32) != 0) {
         g_autofree char *path = object_get_canonical_path(OBJECT(s));

         error_setg(errp,
                    "%s.efuse-size: %u: property value not multiple of 32.",
                    path, s->efuse_size);
         return;
     }

     s->fuse32 = g_malloc0(efuse_bytes(s));
     if (efuse_bdrv_read(s, errp)) {
         g_free(s->fuse32);
     }
 }

 static void efuse_finalize(Object *obj)
 {
     XlnxEFuse *s = XLNX_EFUSE(obj);

     g_free(s->ro_bits);
 }

 static void efuse_prop_set_drive(Object *obj, Visitor *v, const char *name,
                                  void *opaque, Error **errp)
 {
     DeviceState *dev = DEVICE(obj);

     qdev_prop_drive.set(obj, v, name, opaque, errp);

     /* Fill initial data if backend is attached after realized */
     if (dev->realized) {
         efuse_bdrv_read(XLNX_EFUSE(obj), errp);
     }
 }

 static void efuse_prop_get_drive(Object *obj, Visitor *v, const char *name,
                                  void *opaque, Error **errp)
 {
     qdev_prop_drive.get(obj, v, name, opaque, errp);
 }

 static void efuse_prop_release_drive(Object *obj, const char *name,
                                      void *opaque)
 {
     qdev_prop_drive.release(obj, name, opaque);
 }

 static const PropertyInfo efuse_prop_drive = {
     .name  = "str",
     .description = "Node name or ID of a block device to use as eFUSE backend",
     .realized_set_allowed = true,
     .get = efuse_prop_get_drive,
     .set = efuse_prop_set_drive,
     .release = efuse_prop_release_drive,
 };

 static Property efuse_properties[] = {
     DEFINE_PROP("drive", XlnxEFuse, blk, efuse_prop_drive, BlockBackend *),
     DEFINE_PROP_UINT8("efuse-nr", XlnxEFuse, efuse_nr, 3),
     DEFINE_PROP_UINT32("efuse-size", XlnxEFuse, efuse_size, 64 * 32),
     DEFINE_PROP_BOOL("init-factory-tbits", XlnxEFuse, init_tbits, true),
     DEFINE_PROP_ARRAY("read-only", XlnxEFuse, ro_bits_cnt, ro_bits,
                       qdev_prop_uint32, uint32_t),
     DEFINE_PROP_END_OF_LIST(),
 };

 static void efuse_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);

     dc->realize = efuse_realize;
     device_class_set_props(dc, efuse_properties);
 }

 static const TypeInfo efuse_info = {
     .name          = TYPE_XLNX_EFUSE,
     .parent        = TYPE_DEVICE,
     .instance_size = sizeof(XlnxEFuse),
     .instance_finalize = efuse_finalize,
     .class_init    = efuse_class_init,
 };

 static void efuse_register_types(void)
 {
     type_register_static(&efuse_info);
 }
 type_init(efuse_register_types)
	/*
	* QEMU model of the EFUSE eFuse
	*
	* Copyright (c) 2015 Xilinx Inc.
	*
	* Written by Edgar E. Iglesias <edgari@xilinx.com>
	*
	* Permission is hereby granted, free of charge, to any person obtaining a copy
	* of this software and associated documentation files (the "Software"), to deal
	* in the Software without restriction, including without limitation the rights
	* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	* copies of the Software, and to permit persons to whom the Software is
	* furnished to do so, subject to the following conditions:
	*
	* The above copyright notice and this permission notice shall be included in
	* all copies or substantial portions of the Software.
	*
	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
	* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
	* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
	* THE SOFTWARE.
	*/

	#include "qemu/osdep.h"
	#include "hw/nvram/xlnx-efuse.h"

	#include "qemu/error-report.h"
	#include "qemu/log.h"
	#include "qapi/error.h"
	#include "sysemu/blockdev.h"
	#include "hw/qdev-properties.h"
	#include "hw/qdev-properties-system.h"

	#define TBIT0_OFFSET 28
	#define TBIT1_OFFSET 29
	#define TBIT2_OFFSET 30
	#define TBIT3_OFFSET 31
	#define TBITS_PATTERN (0x0AU << TBIT0_OFFSET)
	#define TBITS_MASK (0x0FU << TBIT0_OFFSET)

	bool xlnx_efuse_get_bit(XlnxEFuse *s, unsigned int bit)
	{
	bool b = s->fuse32[bit / 32] & (1 << (bit % 32));
	return b;
	}

	static int efuse_bytes(XlnxEFuse *s)
	{
	return ROUND_UP((s->efuse_nr * s->efuse_size) / 8, 4);
	}

	static int efuse_bdrv_read(XlnxEFuse s, Error *errp)
	{
	uint32_t *ram = s->fuse32;
	int nr = efuse_bytes(s);

	if (!s->blk) {
	return 0;
	}

	s->blk_ro = !blk_supports_write_perm(s->blk);
	if (!s->blk_ro) {
	int rc;

	rc = blk_set_perm(s->blk,
	(BLK_PERM_CONSISTENT_READ \| BLK_PERM_WRITE),
	BLK_PERM_ALL, NULL);
	if (rc) {
	s->blk_ro = true;
	}
	}
	if (s->blk_ro) {
	warn_report("%s: Skip saving updates to read-only eFUSE backstore.",
	blk_name(s->blk));
	}

	if (blk_pread(s->blk, 0, nr, ram, 0) < 0) {
	error_setg(errp, "%s: Failed to read %u bytes from eFUSE backstore.",
	blk_name(s->blk), nr);
	return -1;
	}

	/* Convert from little-endian backstore for each 32-bit row */
	nr /= 4;
	while (nr--) {
	ram[nr] = le32_to_cpu(ram[nr]);
	}

	return 0;
	}

	static void efuse_bdrv_sync(XlnxEFuse *s, unsigned int bit)
	{
	unsigned int row_offset;
	uint32_t le32;

	if (!s->blk \|\| s->blk_ro) {
	return; /* Silent on read-only backend to avoid message flood */
	}

	/* Backstore is always in little-endian */
	le32 = cpu_to_le32(xlnx_efuse_get_row(s, bit));

	row_offset = (bit / 32) * 4;
	if (blk_pwrite(s->blk, row_offset, 4, &le32, 0) < 0) {
	error_report("%s: Failed to write offset %u of eFUSE backstore.",
	blk_name(s->blk), row_offset);
	}
	}

	static int efuse_ro_bits_cmp(const void a, const void b)
	{
	uint32_t i = (const uint32_t )a;
	uint32_t j = (const uint32_t )b;

	return (i > j) - (i < j);
	}

	static void efuse_ro_bits_sort(XlnxEFuse *s)
	{
	uint32_t *ary = s->ro_bits;
	const uint32_t cnt = s->ro_bits_cnt;

	if (ary && cnt > 1) {
	qsort(ary, cnt, sizeof(ary[0]), efuse_ro_bits_cmp);
	}
	}

	static bool efuse_ro_bits_find(XlnxEFuse *s, uint32_t k)
	{
	const uint32_t *ary = s->ro_bits;
	const uint32_t cnt = s->ro_bits_cnt;

	if (!ary \|\| !cnt) {
	return false;
	}

	return bsearch(&k, ary, cnt, sizeof(ary[0]), efuse_ro_bits_cmp) != NULL;
	}

	bool xlnx_efuse_set_bit(XlnxEFuse *s, unsigned int bit)
	{
	uint32_t set, *row;

	if (efuse_ro_bits_find(s, bit)) {
	g_autofree char *path = object_get_canonical_path(OBJECT(s));

	qemu_log_mask(LOG_GUEST_ERROR, "%s: WARN: "
	"Ignored setting of readonly efuse bit<%u,%u>!\n",
	path, (bit / 32), (bit % 32));
	return false;
	}

	/* Avoid back-end write unless there is a real update */
	row = &s->fuse32[bit / 32];
	set = 1 << (bit % 32);
	if (!(set & *row)) {
	*row \|= set;
	efuse_bdrv_sync(s, bit);
	}
	return true;
	}

	bool xlnx_efuse_k256_check(XlnxEFuse *s, uint32_t crc, unsigned start)
	{
	uint32_t calc;

	/* A key always occupies multiple of whole rows */
	assert((start % 32) == 0);

	calc = xlnx_efuse_calc_crc(&s->fuse32[start / 32], (256 / 32), 0);
	return calc == crc;
	}

	uint32_t xlnx_efuse_tbits_check(XlnxEFuse *s)
	{
	int nr;
	uint32_t check = 0;

	for (nr = s->efuse_nr; nr-- > 0; ) {
	int efuse_start_row_num = (s->efuse_size * nr) / 32;
	uint32_t data = s->fuse32[efuse_start_row_num];

	/*
	* If the option is on, auto-init blank T-bits.
	* (non-blank will still be reported as '0' in the check, e.g.,
	* for error-injection tests)
	*/
	if ((data & TBITS_MASK) == 0 && s->init_tbits) {
	data \|= TBITS_PATTERN;

	s->fuse32[efuse_start_row_num] = data;
	efuse_bdrv_sync(s, (efuse_start_row_num * 32 + TBIT0_OFFSET));
	}

	check = (check << 1) \| ((data & TBITS_MASK) == TBITS_PATTERN);
	}

	return check;
	}

	static void efuse_realize(DeviceState dev, Error *errp)
	{
	XlnxEFuse *s = XLNX_EFUSE(dev);

	/* Sort readonly-list for bsearch lookup */
	efuse_ro_bits_sort(s);

	if ((s->efuse_size % 32) != 0) {
	g_autofree char *path = object_get_canonical_path(OBJECT(s));

	error_setg(errp,
	"%s.efuse-size: %u: property value not multiple of 32.",
	path, s->efuse_size);
	return;
	}

	s->fuse32 = g_malloc0(efuse_bytes(s));
	if (efuse_bdrv_read(s, errp)) {
	g_free(s->fuse32);
	}
	}

	static void efuse_finalize(Object *obj)
	{
	XlnxEFuse *s = XLNX_EFUSE(obj);

	g_free(s->ro_bits);
	}

	static void efuse_prop_set_drive(Object obj, Visitor v, const char *name,
	void opaque, Error *errp)
	{
	DeviceState *dev = DEVICE(obj);

	qdev_prop_drive.set(obj, v, name, opaque, errp);

	/* Fill initial data if backend is attached after realized */
	if (dev->realized) {
	efuse_bdrv_read(XLNX_EFUSE(obj), errp);
	}
	}

	static void efuse_prop_get_drive(Object obj, Visitor v, const char *name,
	void opaque, Error *errp)
	{
	qdev_prop_drive.get(obj, v, name, opaque, errp);
	}

	static void efuse_prop_release_drive(Object obj, const char name,
	void *opaque)
	{
	qdev_prop_drive.release(obj, name, opaque);
	}

	static const PropertyInfo efuse_prop_drive = {
	.name = "str",
	.description = "Node name or ID of a block device to use as eFUSE backend",
	.realized_set_allowed = true,
	.get = efuse_prop_get_drive,
	.set = efuse_prop_set_drive,
	.release = efuse_prop_release_drive,
	};

	static Property efuse_properties[] = {
	DEFINE_PROP("drive", XlnxEFuse, blk, efuse_prop_drive, BlockBackend *),
	DEFINE_PROP_UINT8("efuse-nr", XlnxEFuse, efuse_nr, 3),
	DEFINE_PROP_UINT32("efuse-size", XlnxEFuse, efuse_size, 64 * 32),
	DEFINE_PROP_BOOL("init-factory-tbits", XlnxEFuse, init_tbits, true),
	DEFINE_PROP_ARRAY("read-only", XlnxEFuse, ro_bits_cnt, ro_bits,
	qdev_prop_uint32, uint32_t),
	DEFINE_PROP_END_OF_LIST(),
	};

	static void efuse_class_init(ObjectClass klass, void data)
	{
	DeviceClass *dc = DEVICE_CLASS(klass);

	dc->realize = efuse_realize;
	device_class_set_props(dc, efuse_properties);
	}

	static const TypeInfo efuse_info = {
	.name = TYPE_XLNX_EFUSE,
	.parent = TYPE_DEVICE,
	.instance_size = sizeof(XlnxEFuse),
	.instance_finalize = efuse_finalize,
	.class_init = efuse_class_init,
	};

	static void efuse_register_types(void)
	{
	type_register_static(&efuse_info);
	}
	type_init(efuse_register_types)