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

 /*
  * QEMU model of the Xilinx BBRAM Battery Backed RAM
  *
  * Copyright (c) 2014-2021 Xilinx Inc.
  *
  * 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-bbram.h"

 #include "qemu/error-report.h"
 #include "qemu/log.h"
 #include "qapi/error.h"
 #include "sysemu/blockdev.h"
 #include "migration/vmstate.h"
 #include "hw/qdev-properties.h"
 #include "hw/qdev-properties-system.h"
 #include "hw/nvram/xlnx-efuse.h"

 #ifndef XLNX_BBRAM_ERR_DEBUG
 #define XLNX_BBRAM_ERR_DEBUG 0
 #endif

 REG32(BBRAM_STATUS, 0x0)
     FIELD(BBRAM_STATUS, AES_CRC_PASS, 9, 1)
     FIELD(BBRAM_STATUS, AES_CRC_DONE, 8, 1)
     FIELD(BBRAM_STATUS, BBRAM_ZEROIZED, 4, 1)
     FIELD(BBRAM_STATUS, PGM_MODE, 0, 1)
 REG32(BBRAM_CTRL, 0x4)
     FIELD(BBRAM_CTRL, ZEROIZE, 0, 1)
 REG32(PGM_MODE, 0x8)
 REG32(BBRAM_AES_CRC, 0xc)
 REG32(BBRAM_0, 0x10)
 REG32(BBRAM_1, 0x14)
 REG32(BBRAM_2, 0x18)
 REG32(BBRAM_3, 0x1c)
 REG32(BBRAM_4, 0x20)
 REG32(BBRAM_5, 0x24)
 REG32(BBRAM_6, 0x28)
 REG32(BBRAM_7, 0x2c)
 REG32(BBRAM_8, 0x30)
 REG32(BBRAM_SLVERR, 0x34)
     FIELD(BBRAM_SLVERR, ENABLE, 0, 1)
 REG32(BBRAM_ISR, 0x38)
     FIELD(BBRAM_ISR, APB_SLVERR, 0, 1)
 REG32(BBRAM_IMR, 0x3c)
     FIELD(BBRAM_IMR, APB_SLVERR, 0, 1)
 REG32(BBRAM_IER, 0x40)
     FIELD(BBRAM_IER, APB_SLVERR, 0, 1)
 REG32(BBRAM_IDR, 0x44)
     FIELD(BBRAM_IDR, APB_SLVERR, 0, 1)
 REG32(BBRAM_MSW_LOCK, 0x4c)
     FIELD(BBRAM_MSW_LOCK, VAL, 0, 1)

 #define R_MAX (R_BBRAM_MSW_LOCK + 1)

 #define RAM_MAX (A_BBRAM_8 + 4 - A_BBRAM_0)

 #define BBRAM_PGM_MAGIC 0x757bdf0d

 QEMU_BUILD_BUG_ON(R_MAX != ARRAY_SIZE(((XlnxBBRam *)0)->regs));

 static bool bbram_msw_locked(XlnxBBRam *s)
 {
     return ARRAY_FIELD_EX32(s->regs, BBRAM_MSW_LOCK, VAL) != 0;
 }

 static bool bbram_pgm_enabled(XlnxBBRam *s)
 {
     return ARRAY_FIELD_EX32(s->regs, BBRAM_STATUS, PGM_MODE) != 0;
 }

 static void bbram_bdrv_error(XlnxBBRam *s, int rc, gchar *detail)
 {
     Error *errp;

     error_setg_errno(&errp, -rc, "%s: BBRAM backstore %s failed.",
                      blk_name(s->blk), detail);
     error_report("%s", error_get_pretty(errp));
     error_free(errp);

     g_free(detail);
 }

 static void bbram_bdrv_read(XlnxBBRam *s, Error **errp)
 {
     uint32_t *ram = &s->regs[R_BBRAM_0];
     int nr = RAM_MAX;

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

     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 BBRAM backstore.",
                     blk_name(s->blk));
     }

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

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

 static void bbram_bdrv_sync(XlnxBBRam *s, uint64_t hwaddr)
 {
     uint32_t le32;
     unsigned offset;
     int rc;

     assert(A_BBRAM_0 <= hwaddr && hwaddr <= A_BBRAM_8);

     /* Backstore is always in little-endian */
     le32 = cpu_to_le32(s->regs[hwaddr / 4]);

     /* Update zeroized flag */
     if (le32 && (hwaddr != A_BBRAM_8 || s->bbram8_wo)) {
         ARRAY_FIELD_DP32(s->regs, BBRAM_STATUS, BBRAM_ZEROIZED, 0);
     }

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

     offset = hwaddr - A_BBRAM_0;
     rc = blk_pwrite(s->blk, offset, &le32, 4, 0);
     if (rc < 0) {
         bbram_bdrv_error(s, rc, g_strdup_printf("write to offset %u", offset));
     }
 }

 static void bbram_bdrv_zero(XlnxBBRam *s)
 {
     int rc;

     ARRAY_FIELD_DP32(s->regs, BBRAM_STATUS, BBRAM_ZEROIZED, 1);

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

     rc = blk_make_zero(s->blk, 0);
     if (rc < 0) {
         bbram_bdrv_error(s, rc, g_strdup("zeroizing"));
     }

     /* Restore bbram8 if it is non-zero */
     if (s->regs[R_BBRAM_8]) {
         bbram_bdrv_sync(s, A_BBRAM_8);
     }
 }

 static void bbram_zeroize(XlnxBBRam *s)
 {
     int nr = RAM_MAX - (s->bbram8_wo ? 0 : 4); /* only wo bbram8 is cleared */

     memset(&s->regs[R_BBRAM_0], 0, nr);
     bbram_bdrv_zero(s);
 }

 static void bbram_update_irq(XlnxBBRam *s)
 {
     bool pending = s->regs[R_BBRAM_ISR] & ~s->regs[R_BBRAM_IMR];

     qemu_set_irq(s->irq_bbram, pending);
 }

 static void bbram_ctrl_postw(RegisterInfo *reg, uint64_t val64)
 {
     XlnxBBRam *s = XLNX_BBRAM(reg->opaque);
     uint32_t val = val64;

     if (val & R_BBRAM_CTRL_ZEROIZE_MASK) {
         bbram_zeroize(s);
         /* The bit is self clearing */
         s->regs[R_BBRAM_CTRL] &= ~R_BBRAM_CTRL_ZEROIZE_MASK;
     }
 }

 static void bbram_pgm_mode_postw(RegisterInfo *reg, uint64_t val64)
 {
     XlnxBBRam *s = XLNX_BBRAM(reg->opaque);
     uint32_t val = val64;

     if (val == BBRAM_PGM_MAGIC) {
         bbram_zeroize(s);

         /* The status bit is cleared only by POR */
         ARRAY_FIELD_DP32(s->regs, BBRAM_STATUS, PGM_MODE, 1);
     }
 }

 static void bbram_aes_crc_postw(RegisterInfo *reg, uint64_t val64)
 {
     XlnxBBRam *s = XLNX_BBRAM(reg->opaque);
     uint32_t calc_crc;

     if (!bbram_pgm_enabled(s)) {
         /* We are not in programming mode, don't do anything */
         return;
     }

     /* Perform the AES integrity check */
     s->regs[R_BBRAM_STATUS] |= R_BBRAM_STATUS_AES_CRC_DONE_MASK;

     /*
      * Set check status.
      *
      * ZynqMP BBRAM check has a zero-u32 prepended; see:
      *  https://github.com/Xilinx/embeddedsw/blob/release-2019.2/lib/sw_services/xilskey/src/xilskey_bbramps_zynqmp.c#L311
      */
     calc_crc = xlnx_efuse_calc_crc(&s->regs[R_BBRAM_0],
                                    (R_BBRAM_8 - R_BBRAM_0), s->crc_zpads);

     ARRAY_FIELD_DP32(s->regs, BBRAM_STATUS, AES_CRC_PASS,
                      (s->regs[R_BBRAM_AES_CRC] == calc_crc));
 }

 static uint64_t bbram_key_prew(RegisterInfo *reg, uint64_t val64)
 {
     XlnxBBRam *s = XLNX_BBRAM(reg->opaque);
     uint32_t original_data = *(uint32_t *) reg->data;

     if (bbram_pgm_enabled(s)) {
         return val64;
     } else {
         /* We are not in programming mode, don't do anything */
         qemu_log_mask(LOG_GUEST_ERROR,
                       "Not in programming mode, dropping the write\n");
         return original_data;
     }
 }

 static void bbram_key_postw(RegisterInfo *reg, uint64_t val64)
 {
     XlnxBBRam *s = XLNX_BBRAM(reg->opaque);

     bbram_bdrv_sync(s, reg->access->addr);
 }

 static uint64_t bbram_wo_postr(RegisterInfo *reg, uint64_t val)
 {
     return 0;
 }

 static uint64_t bbram_r8_postr(RegisterInfo *reg, uint64_t val)
 {
     XlnxBBRam *s = XLNX_BBRAM(reg->opaque);

     return s->bbram8_wo ? bbram_wo_postr(reg, val) : val;
 }

 static bool bbram_r8_readonly(XlnxBBRam *s)
 {
     return !bbram_pgm_enabled(s) || bbram_msw_locked(s);
 }

 static uint64_t bbram_r8_prew(RegisterInfo *reg, uint64_t val64)
 {
     XlnxBBRam *s = XLNX_BBRAM(reg->opaque);

     if (bbram_r8_readonly(s)) {
         val64 = *(uint32_t *)reg->data;
     }

     return val64;
 }

 static void bbram_r8_postw(RegisterInfo *reg, uint64_t val64)
 {
     XlnxBBRam *s = XLNX_BBRAM(reg->opaque);

     if (!bbram_r8_readonly(s)) {
         bbram_bdrv_sync(s, A_BBRAM_8);
     }
 }

 static uint64_t bbram_msw_lock_prew(RegisterInfo *reg, uint64_t val64)
 {
     XlnxBBRam *s = XLNX_BBRAM(reg->opaque);

     /* Never lock if bbram8 is wo; and, only POR can clear the lock */
     if (s->bbram8_wo) {
         val64 = 0;
     } else {
         val64 |= s->regs[R_BBRAM_MSW_LOCK];
     }

     return val64;
 }

 static void bbram_isr_postw(RegisterInfo *reg, uint64_t val64)
 {
     XlnxBBRam *s = XLNX_BBRAM(reg->opaque);

     bbram_update_irq(s);
 }

 static uint64_t bbram_ier_prew(RegisterInfo *reg, uint64_t val64)
 {
     XlnxBBRam *s = XLNX_BBRAM(reg->opaque);
     uint32_t val = val64;

     s->regs[R_BBRAM_IMR] &= ~val;
     bbram_update_irq(s);
     return 0;
 }

 static uint64_t bbram_idr_prew(RegisterInfo *reg, uint64_t val64)
 {
     XlnxBBRam *s = XLNX_BBRAM(reg->opaque);
     uint32_t val = val64;

     s->regs[R_BBRAM_IMR] |= val;
     bbram_update_irq(s);
     return 0;
 }

 static RegisterAccessInfo bbram_ctrl_regs_info[] = {
     {   .name = "BBRAM_STATUS",  .addr = A_BBRAM_STATUS,
         .rsvd = 0xee,
         .ro = 0x3ff,
     },{ .name = "BBRAM_CTRL",  .addr = A_BBRAM_CTRL,
         .post_write = bbram_ctrl_postw,
     },{ .name = "PGM_MODE",  .addr = A_PGM_MODE,
         .post_write = bbram_pgm_mode_postw,
     },{ .name = "BBRAM_AES_CRC",  .addr = A_BBRAM_AES_CRC,
         .post_write = bbram_aes_crc_postw,
         .post_read = bbram_wo_postr,
     },{ .name = "BBRAM_0",  .addr = A_BBRAM_0,
         .pre_write = bbram_key_prew,
         .post_write = bbram_key_postw,
         .post_read = bbram_wo_postr,
     },{ .name = "BBRAM_1",  .addr = A_BBRAM_1,
         .pre_write = bbram_key_prew,
         .post_write = bbram_key_postw,
         .post_read = bbram_wo_postr,
     },{ .name = "BBRAM_2",  .addr = A_BBRAM_2,
         .pre_write = bbram_key_prew,
         .post_write = bbram_key_postw,
         .post_read = bbram_wo_postr,
     },{ .name = "BBRAM_3",  .addr = A_BBRAM_3,
         .pre_write = bbram_key_prew,
         .post_write = bbram_key_postw,
         .post_read = bbram_wo_postr,
     },{ .name = "BBRAM_4",  .addr = A_BBRAM_4,
         .pre_write = bbram_key_prew,
         .post_write = bbram_key_postw,
         .post_read = bbram_wo_postr,
     },{ .name = "BBRAM_5",  .addr = A_BBRAM_5,
         .pre_write = bbram_key_prew,
         .post_write = bbram_key_postw,
         .post_read = bbram_wo_postr,
     },{ .name = "BBRAM_6",  .addr = A_BBRAM_6,
         .pre_write = bbram_key_prew,
         .post_write = bbram_key_postw,
         .post_read = bbram_wo_postr,
     },{ .name = "BBRAM_7",  .addr = A_BBRAM_7,
         .pre_write = bbram_key_prew,
         .post_write = bbram_key_postw,
         .post_read = bbram_wo_postr,
     },{ .name = "BBRAM_8",  .addr = A_BBRAM_8,
         .pre_write = bbram_r8_prew,
         .post_write = bbram_r8_postw,
         .post_read = bbram_r8_postr,
     },{ .name = "BBRAM_SLVERR",  .addr = A_BBRAM_SLVERR,
         .rsvd = ~1,
     },{ .name = "BBRAM_ISR",  .addr = A_BBRAM_ISR,
         .w1c = 0x1,
         .post_write = bbram_isr_postw,
     },{ .name = "BBRAM_IMR",  .addr = A_BBRAM_IMR,
         .ro = 0x1,
     },{ .name = "BBRAM_IER",  .addr = A_BBRAM_IER,
         .pre_write = bbram_ier_prew,
     },{ .name = "BBRAM_IDR",  .addr = A_BBRAM_IDR,
         .pre_write = bbram_idr_prew,
     },{ .name = "BBRAM_MSW_LOCK",  .addr = A_BBRAM_MSW_LOCK,
         .pre_write = bbram_msw_lock_prew,
         .ro = ~R_BBRAM_MSW_LOCK_VAL_MASK,
     }
 };

 static void bbram_ctrl_reset(DeviceState *dev)
 {
     XlnxBBRam *s = XLNX_BBRAM(dev);
     unsigned int i;

     for (i = 0; i < ARRAY_SIZE(s->regs_info); ++i) {
         if (i < R_BBRAM_0 || i > R_BBRAM_8) {
             register_reset(&s->regs_info[i]);
         }
     }

     bbram_update_irq(s);
 }

 static const MemoryRegionOps bbram_ctrl_ops = {
     .read = register_read_memory,
     .write = register_write_memory,
     .endianness = DEVICE_LITTLE_ENDIAN,
     .valid = {
         .min_access_size = 4,
         .max_access_size = 4,
     },
 };

 static void bbram_ctrl_realize(DeviceState *dev, Error **errp)
 {
     XlnxBBRam *s = XLNX_BBRAM(dev);

     if (s->crc_zpads) {
         s->bbram8_wo = true;
     }

     bbram_bdrv_read(s, errp);
 }

 static void bbram_ctrl_init(Object *obj)
 {
     XlnxBBRam *s = XLNX_BBRAM(obj);
     SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
     RegisterInfoArray *reg_array;

     reg_array =
         register_init_block32(DEVICE(obj), bbram_ctrl_regs_info,
                               ARRAY_SIZE(bbram_ctrl_regs_info),
                               s->regs_info, s->regs,
                               &bbram_ctrl_ops,
                               XLNX_BBRAM_ERR_DEBUG,
                               R_MAX * 4);

     sysbus_init_mmio(sbd, &reg_array->mem);
     sysbus_init_irq(sbd, &s->irq_bbram);
 }

 static void bbram_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) {
         bbram_bdrv_read(XLNX_BBRAM(obj), errp);
     }
 }

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

 static const PropertyInfo bbram_prop_drive = {
     .name  = "str",
     .description = "Node name or ID of a block device to use as BBRAM backend",
     .realized_set_allowed = true,
     .get = bbram_prop_get_drive,
     .set = bbram_prop_set_drive,
     .release = bbram_prop_release_drive,
 };

 static const VMStateDescription vmstate_bbram_ctrl = {
     .name = TYPE_XLNX_BBRAM,
     .version_id = 1,
     .minimum_version_id = 1,
     .fields = (VMStateField[]) {
         VMSTATE_UINT32_ARRAY(regs, XlnxBBRam, R_MAX),
         VMSTATE_END_OF_LIST(),
     }
 };

 static Property bbram_ctrl_props[] = {
     DEFINE_PROP("drive", XlnxBBRam, blk, bbram_prop_drive, BlockBackend *),
     DEFINE_PROP_UINT32("crc-zpads", XlnxBBRam, crc_zpads, 1),
     DEFINE_PROP_END_OF_LIST(),
 };

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

     dc->reset = bbram_ctrl_reset;
     dc->realize = bbram_ctrl_realize;
     dc->vmsd = &vmstate_bbram_ctrl;
     device_class_set_props(dc, bbram_ctrl_props);
 }

 static const TypeInfo bbram_ctrl_info = {
     .name          = TYPE_XLNX_BBRAM,
     .parent        = TYPE_SYS_BUS_DEVICE,
     .instance_size = sizeof(XlnxBBRam),
     .class_init    = bbram_ctrl_class_init,
     .instance_init = bbram_ctrl_init,
 };

 static void bbram_ctrl_register_types(void)
 {
     type_register_static(&bbram_ctrl_info);
 }

 type_init(bbram_ctrl_register_types)
	/*
	* QEMU model of the Xilinx BBRAM Battery Backed RAM
	*
	* Copyright (c) 2014-2021 Xilinx Inc.
	*
	* 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-bbram.h"

	#include "qemu/error-report.h"
	#include "qemu/log.h"
	#include "qapi/error.h"
	#include "sysemu/blockdev.h"
	#include "migration/vmstate.h"
	#include "hw/qdev-properties.h"
	#include "hw/qdev-properties-system.h"
	#include "hw/nvram/xlnx-efuse.h"

	#ifndef XLNX_BBRAM_ERR_DEBUG
	#define XLNX_BBRAM_ERR_DEBUG 0
	#endif

	REG32(BBRAM_STATUS, 0x0)
	FIELD(BBRAM_STATUS, AES_CRC_PASS, 9, 1)
	FIELD(BBRAM_STATUS, AES_CRC_DONE, 8, 1)
	FIELD(BBRAM_STATUS, BBRAM_ZEROIZED, 4, 1)
	FIELD(BBRAM_STATUS, PGM_MODE, 0, 1)
	REG32(BBRAM_CTRL, 0x4)
	FIELD(BBRAM_CTRL, ZEROIZE, 0, 1)
	REG32(PGM_MODE, 0x8)
	REG32(BBRAM_AES_CRC, 0xc)
	REG32(BBRAM_0, 0x10)
	REG32(BBRAM_1, 0x14)
	REG32(BBRAM_2, 0x18)
	REG32(BBRAM_3, 0x1c)
	REG32(BBRAM_4, 0x20)
	REG32(BBRAM_5, 0x24)
	REG32(BBRAM_6, 0x28)
	REG32(BBRAM_7, 0x2c)
	REG32(BBRAM_8, 0x30)
	REG32(BBRAM_SLVERR, 0x34)
	FIELD(BBRAM_SLVERR, ENABLE, 0, 1)
	REG32(BBRAM_ISR, 0x38)
	FIELD(BBRAM_ISR, APB_SLVERR, 0, 1)
	REG32(BBRAM_IMR, 0x3c)
	FIELD(BBRAM_IMR, APB_SLVERR, 0, 1)
	REG32(BBRAM_IER, 0x40)
	FIELD(BBRAM_IER, APB_SLVERR, 0, 1)
	REG32(BBRAM_IDR, 0x44)
	FIELD(BBRAM_IDR, APB_SLVERR, 0, 1)
	REG32(BBRAM_MSW_LOCK, 0x4c)
	FIELD(BBRAM_MSW_LOCK, VAL, 0, 1)

	#define R_MAX (R_BBRAM_MSW_LOCK + 1)

	#define RAM_MAX (A_BBRAM_8 + 4 - A_BBRAM_0)

	#define BBRAM_PGM_MAGIC 0x757bdf0d

	QEMU_BUILD_BUG_ON(R_MAX != ARRAY_SIZE(((XlnxBBRam *)0)->regs));

	static bool bbram_msw_locked(XlnxBBRam *s)
	{
	return ARRAY_FIELD_EX32(s->regs, BBRAM_MSW_LOCK, VAL) != 0;
	}

	static bool bbram_pgm_enabled(XlnxBBRam *s)
	{
	return ARRAY_FIELD_EX32(s->regs, BBRAM_STATUS, PGM_MODE) != 0;
	}

	static void bbram_bdrv_error(XlnxBBRam s, int rc, gchar detail)
	{
	Error *errp;

	error_setg_errno(&errp, -rc, "%s: BBRAM backstore %s failed.",
	blk_name(s->blk), detail);
	error_report("%s", error_get_pretty(errp));
	error_free(errp);

	g_free(detail);
	}

	static void bbram_bdrv_read(XlnxBBRam s, Error *errp)
	{
	uint32_t *ram = &s->regs[R_BBRAM_0];
	int nr = RAM_MAX;

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

	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 BBRAM backstore.",
	blk_name(s->blk));
	}

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

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

	static void bbram_bdrv_sync(XlnxBBRam *s, uint64_t hwaddr)
	{
	uint32_t le32;
	unsigned offset;
	int rc;

	assert(A_BBRAM_0 <= hwaddr && hwaddr <= A_BBRAM_8);

	/* Backstore is always in little-endian */
	le32 = cpu_to_le32(s->regs[hwaddr / 4]);

	/* Update zeroized flag */
	if (le32 && (hwaddr != A_BBRAM_8 \|\| s->bbram8_wo)) {
	ARRAY_FIELD_DP32(s->regs, BBRAM_STATUS, BBRAM_ZEROIZED, 0);
	}

	if (!s->blk \|\| s->blk_ro) {
	return;
	}

	offset = hwaddr - A_BBRAM_0;
	rc = blk_pwrite(s->blk, offset, &le32, 4, 0);
	if (rc < 0) {
	bbram_bdrv_error(s, rc, g_strdup_printf("write to offset %u", offset));
	}
	}

	static void bbram_bdrv_zero(XlnxBBRam *s)
	{
	int rc;

	ARRAY_FIELD_DP32(s->regs, BBRAM_STATUS, BBRAM_ZEROIZED, 1);

	if (!s->blk \|\| s->blk_ro) {
	return;
	}

	rc = blk_make_zero(s->blk, 0);
	if (rc < 0) {
	bbram_bdrv_error(s, rc, g_strdup("zeroizing"));
	}

	/* Restore bbram8 if it is non-zero */
	if (s->regs[R_BBRAM_8]) {
	bbram_bdrv_sync(s, A_BBRAM_8);
	}
	}

	static void bbram_zeroize(XlnxBBRam *s)
	{
	int nr = RAM_MAX - (s->bbram8_wo ? 0 : 4); /* only wo bbram8 is cleared */

	memset(&s->regs[R_BBRAM_0], 0, nr);
	bbram_bdrv_zero(s);
	}

	static void bbram_update_irq(XlnxBBRam *s)
	{
	bool pending = s->regs[R_BBRAM_ISR] & ~s->regs[R_BBRAM_IMR];

	qemu_set_irq(s->irq_bbram, pending);
	}

	static void bbram_ctrl_postw(RegisterInfo *reg, uint64_t val64)
	{
	XlnxBBRam *s = XLNX_BBRAM(reg->opaque);
	uint32_t val = val64;

	if (val & R_BBRAM_CTRL_ZEROIZE_MASK) {
	bbram_zeroize(s);
	/* The bit is self clearing */
	s->regs[R_BBRAM_CTRL] &= ~R_BBRAM_CTRL_ZEROIZE_MASK;
	}
	}

	static void bbram_pgm_mode_postw(RegisterInfo *reg, uint64_t val64)
	{
	XlnxBBRam *s = XLNX_BBRAM(reg->opaque);
	uint32_t val = val64;

	if (val == BBRAM_PGM_MAGIC) {
	bbram_zeroize(s);

	/* The status bit is cleared only by POR */
	ARRAY_FIELD_DP32(s->regs, BBRAM_STATUS, PGM_MODE, 1);
	}
	}

	static void bbram_aes_crc_postw(RegisterInfo *reg, uint64_t val64)
	{
	XlnxBBRam *s = XLNX_BBRAM(reg->opaque);
	uint32_t calc_crc;

	if (!bbram_pgm_enabled(s)) {
	/* We are not in programming mode, don't do anything */
	return;
	}

	/* Perform the AES integrity check */
	s->regs[R_BBRAM_STATUS] \|= R_BBRAM_STATUS_AES_CRC_DONE_MASK;

	/*
	* Set check status.
	*
	* ZynqMP BBRAM check has a zero-u32 prepended; see:
	* https://github.com/Xilinx/embeddedsw/blob/release-2019.2/lib/sw_services/xilskey/src/xilskey_bbramps_zynqmp.c#L311
	*/
	calc_crc = xlnx_efuse_calc_crc(&s->regs[R_BBRAM_0],
	(R_BBRAM_8 - R_BBRAM_0), s->crc_zpads);

	ARRAY_FIELD_DP32(s->regs, BBRAM_STATUS, AES_CRC_PASS,
	(s->regs[R_BBRAM_AES_CRC] == calc_crc));
	}

	static uint64_t bbram_key_prew(RegisterInfo *reg, uint64_t val64)
	{
	XlnxBBRam *s = XLNX_BBRAM(reg->opaque);
	uint32_t original_data = (uint32_t ) reg->data;

	if (bbram_pgm_enabled(s)) {
	return val64;
	} else {
	/* We are not in programming mode, don't do anything */
	qemu_log_mask(LOG_GUEST_ERROR,
	"Not in programming mode, dropping the write\n");
	return original_data;
	}
	}

	static void bbram_key_postw(RegisterInfo *reg, uint64_t val64)
	{
	XlnxBBRam *s = XLNX_BBRAM(reg->opaque);

	bbram_bdrv_sync(s, reg->access->addr);
	}

	static uint64_t bbram_wo_postr(RegisterInfo *reg, uint64_t val)
	{
	return 0;
	}

	static uint64_t bbram_r8_postr(RegisterInfo *reg, uint64_t val)
	{
	XlnxBBRam *s = XLNX_BBRAM(reg->opaque);

	return s->bbram8_wo ? bbram_wo_postr(reg, val) : val;
	}

	static bool bbram_r8_readonly(XlnxBBRam *s)
	{
	return !bbram_pgm_enabled(s) \|\| bbram_msw_locked(s);
	}

	static uint64_t bbram_r8_prew(RegisterInfo *reg, uint64_t val64)
	{
	XlnxBBRam *s = XLNX_BBRAM(reg->opaque);

	if (bbram_r8_readonly(s)) {
	val64 = (uint32_t )reg->data;
	}

	return val64;
	}

	static void bbram_r8_postw(RegisterInfo *reg, uint64_t val64)
	{
	XlnxBBRam *s = XLNX_BBRAM(reg->opaque);

	if (!bbram_r8_readonly(s)) {
	bbram_bdrv_sync(s, A_BBRAM_8);
	}
	}

	static uint64_t bbram_msw_lock_prew(RegisterInfo *reg, uint64_t val64)
	{
	XlnxBBRam *s = XLNX_BBRAM(reg->opaque);

	/* Never lock if bbram8 is wo; and, only POR can clear the lock */
	if (s->bbram8_wo) {
	val64 = 0;
	} else {
	val64 \|= s->regs[R_BBRAM_MSW_LOCK];
	}

	return val64;
	}

	static void bbram_isr_postw(RegisterInfo *reg, uint64_t val64)
	{
	XlnxBBRam *s = XLNX_BBRAM(reg->opaque);

	bbram_update_irq(s);
	}

	static uint64_t bbram_ier_prew(RegisterInfo *reg, uint64_t val64)
	{
	XlnxBBRam *s = XLNX_BBRAM(reg->opaque);
	uint32_t val = val64;

	s->regs[R_BBRAM_IMR] &= ~val;
	bbram_update_irq(s);
	return 0;
	}

	static uint64_t bbram_idr_prew(RegisterInfo *reg, uint64_t val64)
	{
	XlnxBBRam *s = XLNX_BBRAM(reg->opaque);
	uint32_t val = val64;

	s->regs[R_BBRAM_IMR] \|= val;
	bbram_update_irq(s);
	return 0;
	}

	static RegisterAccessInfo bbram_ctrl_regs_info[] = {
	{ .name = "BBRAM_STATUS", .addr = A_BBRAM_STATUS,
	.rsvd = 0xee,
	.ro = 0x3ff,
	},{ .name = "BBRAM_CTRL", .addr = A_BBRAM_CTRL,
	.post_write = bbram_ctrl_postw,
	},{ .name = "PGM_MODE", .addr = A_PGM_MODE,
	.post_write = bbram_pgm_mode_postw,
	},{ .name = "BBRAM_AES_CRC", .addr = A_BBRAM_AES_CRC,
	.post_write = bbram_aes_crc_postw,
	.post_read = bbram_wo_postr,
	},{ .name = "BBRAM_0", .addr = A_BBRAM_0,
	.pre_write = bbram_key_prew,
	.post_write = bbram_key_postw,
	.post_read = bbram_wo_postr,
	},{ .name = "BBRAM_1", .addr = A_BBRAM_1,
	.pre_write = bbram_key_prew,
	.post_write = bbram_key_postw,
	.post_read = bbram_wo_postr,
	},{ .name = "BBRAM_2", .addr = A_BBRAM_2,
	.pre_write = bbram_key_prew,
	.post_write = bbram_key_postw,
	.post_read = bbram_wo_postr,
	},{ .name = "BBRAM_3", .addr = A_BBRAM_3,
	.pre_write = bbram_key_prew,
	.post_write = bbram_key_postw,
	.post_read = bbram_wo_postr,
	},{ .name = "BBRAM_4", .addr = A_BBRAM_4,
	.pre_write = bbram_key_prew,
	.post_write = bbram_key_postw,
	.post_read = bbram_wo_postr,
	},{ .name = "BBRAM_5", .addr = A_BBRAM_5,
	.pre_write = bbram_key_prew,
	.post_write = bbram_key_postw,
	.post_read = bbram_wo_postr,
	},{ .name = "BBRAM_6", .addr = A_BBRAM_6,
	.pre_write = bbram_key_prew,
	.post_write = bbram_key_postw,
	.post_read = bbram_wo_postr,
	},{ .name = "BBRAM_7", .addr = A_BBRAM_7,
	.pre_write = bbram_key_prew,
	.post_write = bbram_key_postw,
	.post_read = bbram_wo_postr,
	},{ .name = "BBRAM_8", .addr = A_BBRAM_8,
	.pre_write = bbram_r8_prew,
	.post_write = bbram_r8_postw,
	.post_read = bbram_r8_postr,
	},{ .name = "BBRAM_SLVERR", .addr = A_BBRAM_SLVERR,
	.rsvd = ~1,
	},{ .name = "BBRAM_ISR", .addr = A_BBRAM_ISR,
	.w1c = 0x1,
	.post_write = bbram_isr_postw,
	},{ .name = "BBRAM_IMR", .addr = A_BBRAM_IMR,
	.ro = 0x1,
	},{ .name = "BBRAM_IER", .addr = A_BBRAM_IER,
	.pre_write = bbram_ier_prew,
	},{ .name = "BBRAM_IDR", .addr = A_BBRAM_IDR,
	.pre_write = bbram_idr_prew,
	},{ .name = "BBRAM_MSW_LOCK", .addr = A_BBRAM_MSW_LOCK,
	.pre_write = bbram_msw_lock_prew,
	.ro = ~R_BBRAM_MSW_LOCK_VAL_MASK,
	}
	};

	static void bbram_ctrl_reset(DeviceState *dev)
	{
	XlnxBBRam *s = XLNX_BBRAM(dev);
	unsigned int i;

	for (i = 0; i < ARRAY_SIZE(s->regs_info); ++i) {
	if (i < R_BBRAM_0 \|\| i > R_BBRAM_8) {
	register_reset(&s->regs_info[i]);
	}
	}

	bbram_update_irq(s);
	}

	static const MemoryRegionOps bbram_ctrl_ops = {
	.read = register_read_memory,
	.write = register_write_memory,
	.endianness = DEVICE_LITTLE_ENDIAN,
	.valid = {
	.min_access_size = 4,
	.max_access_size = 4,
	},
	};

	static void bbram_ctrl_realize(DeviceState dev, Error *errp)
	{
	XlnxBBRam *s = XLNX_BBRAM(dev);

	if (s->crc_zpads) {
	s->bbram8_wo = true;
	}

	bbram_bdrv_read(s, errp);
	}

	static void bbram_ctrl_init(Object *obj)
	{
	XlnxBBRam *s = XLNX_BBRAM(obj);
	SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
	RegisterInfoArray *reg_array;

	reg_array =
	register_init_block32(DEVICE(obj), bbram_ctrl_regs_info,
	ARRAY_SIZE(bbram_ctrl_regs_info),
	s->regs_info, s->regs,
	&bbram_ctrl_ops,
	XLNX_BBRAM_ERR_DEBUG,
	R_MAX * 4);

	sysbus_init_mmio(sbd, &reg_array->mem);
	sysbus_init_irq(sbd, &s->irq_bbram);
	}

	static void bbram_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) {
	bbram_bdrv_read(XLNX_BBRAM(obj), errp);
	}
	}

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

	static const PropertyInfo bbram_prop_drive = {
	.name = "str",
	.description = "Node name or ID of a block device to use as BBRAM backend",
	.realized_set_allowed = true,
	.get = bbram_prop_get_drive,
	.set = bbram_prop_set_drive,
	.release = bbram_prop_release_drive,
	};

	static const VMStateDescription vmstate_bbram_ctrl = {
	.name = TYPE_XLNX_BBRAM,
	.version_id = 1,
	.minimum_version_id = 1,
	.fields = (VMStateField[]) {
	VMSTATE_UINT32_ARRAY(regs, XlnxBBRam, R_MAX),
	VMSTATE_END_OF_LIST(),
	}
	};

	static Property bbram_ctrl_props[] = {
	DEFINE_PROP("drive", XlnxBBRam, blk, bbram_prop_drive, BlockBackend *),
	DEFINE_PROP_UINT32("crc-zpads", XlnxBBRam, crc_zpads, 1),
	DEFINE_PROP_END_OF_LIST(),
	};

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

	dc->reset = bbram_ctrl_reset;
	dc->realize = bbram_ctrl_realize;
	dc->vmsd = &vmstate_bbram_ctrl;
	device_class_set_props(dc, bbram_ctrl_props);
	}

	static const TypeInfo bbram_ctrl_info = {
	.name = TYPE_XLNX_BBRAM,
	.parent = TYPE_SYS_BUS_DEVICE,
	.instance_size = sizeof(XlnxBBRam),
	.class_init = bbram_ctrl_class_init,
	.instance_init = bbram_ctrl_init,
	};

	static void bbram_ctrl_register_types(void)
	{
	type_register_static(&bbram_ctrl_info);
	}

	type_init(bbram_ctrl_register_types)