hw/nvram: Introduce Xilinx eFuse QOM

This introduces the QOM for Xilinx eFuse, an one-time
field-programmable storage bit array.

The actual mmio interface to the array varies by device
families and will be provided in different change-sets.

Co-authored-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Co-authored-by: Sai Pavan Boddu <sai.pavan.boddu@xilinx.com>

Signed-off-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Signed-off-by: Sai Pavan Boddu <sai.pavan.boddu@xilinx.com>
Signed-off-by: Tong Ho <tong.ho@xilinx.com>
Message-id: 20210917052400.1249094-2-tong.ho@xilinx.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

include/hw/nvram/xlnx-efuse.h

@@ -0,0 +1,132 @@
+/*
+ * QEMU model of the Xilinx eFuse core
+ *
+ * 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.
+ */
+
+#ifndef XLNX_EFUSE_H
+#define XLNX_EFUSE_H
+
+#include "sysemu/block-backend.h"
+#include "hw/qdev-core.h"
+
+#define TYPE_XLNX_EFUSE "xlnx,efuse"
+OBJECT_DECLARE_SIMPLE_TYPE(XlnxEFuse, XLNX_EFUSE);
+
+struct XlnxEFuse {
+    DeviceState parent_obj;
+    BlockBackend *blk;
+    bool blk_ro;
+    uint32_t *fuse32;
+
+    DeviceState *dev;
+
+    bool init_tbits;
+
+    uint8_t efuse_nr;
+    uint32_t efuse_size;
+
+    uint32_t *ro_bits;
+    uint32_t ro_bits_cnt;
+};
+
+/**
+ * xlnx_efuse_calc_crc:
+ * @data: an array of 32-bit words for which the CRC should be computed
+ * @u32_cnt: the array size in number of 32-bit words
+ * @zpads: the number of 32-bit zeros prepended to @data before computation
+ *
+ * This function is used to compute the CRC for an array of 32-bit words,
+ * using a Xilinx-specific data padding.
+ *
+ * Returns: the computed 32-bit CRC
+ */
+uint32_t xlnx_efuse_calc_crc(const uint32_t *data, unsigned u32_cnt,
+                             unsigned zpads);
+
+/**
+ * xlnx_efuse_get_bit:
+ * @s: the efuse object
+ * @bit: the efuse bit-address to read the data
+ *
+ * Returns: the bit, 0 or 1, at @bit of object @s
+ */
+bool xlnx_efuse_get_bit(XlnxEFuse *s, unsigned int bit);
+
+/**
+ * xlnx_efuse_set_bit:
+ * @s: the efuse object
+ * @bit: the efuse bit-address to be written a value of 1
+ *
+ * Returns: true on success, false on failure
+ */
+bool xlnx_efuse_set_bit(XlnxEFuse *s, unsigned int bit);
+
+/**
+ * xlnx_efuse_k256_check:
+ * @s: the efuse object
+ * @crc: the 32-bit CRC to be compared with
+ * @start: the efuse bit-address (which must be multiple of 32) of the
+ *         start of a 256-bit array
+ *
+ * This function computes the CRC of a 256-bit array starting at @start
+ * then compares to the given @crc
+ *
+ * Returns: true of @crc == computed, false otherwise
+ */
+bool xlnx_efuse_k256_check(XlnxEFuse *s, uint32_t crc, unsigned start);
+
+/**
+ * xlnx_efuse_tbits_check:
+ * @s: the efuse object
+ *
+ * This function inspects a number of efuse bits at specific addresses
+ * to see if they match a validation pattern. Each pattern is a group
+ * of 4 bits, and there are 3 groups.
+ *
+ * Returns: a 3-bit mask, where a bit of '1' means the corresponding
+ * group has a valid pattern.
+ */
+uint32_t xlnx_efuse_tbits_check(XlnxEFuse *s);
+
+/**
+ * xlnx_efuse_get_row:
+ * @s: the efuse object
+ * @bit: the efuse bit address for which a 32-bit value is read
+ *
+ * Returns: the entire 32 bits of the efuse, starting at a bit
+ * address that is multiple of 32 and contains the bit at @bit
+ */
+static inline uint32_t xlnx_efuse_get_row(XlnxEFuse *s, unsigned int bit)
+{
+    if (!(s->fuse32)) {
+        return 0;
+    } else {
+        unsigned int row_idx = bit / 32;
+
+        assert(row_idx < (s->efuse_size * s->efuse_nr / 32));
+        return s->fuse32[row_idx];
+    }
+}
+
+#endif