diff options
| -rw-r--r-- | hw/core/Makefile.objs | 1 | ||||
| -rw-r--r-- | hw/core/register.c | 160 | ||||
| -rw-r--r-- | include/hw/register.h | 112 |
3 files changed, 273 insertions, 0 deletions
diff --git a/hw/core/Makefile.objs b/hw/core/Makefile.objs index 82a9ef84f8..cfd4840397 100644 --- a/hw/core/Makefile.objs +++ b/hw/core/Makefile.objs @@ -15,4 +15,5 @@ common-obj-$(CONFIG_SOFTMMU) += machine.o common-obj-$(CONFIG_SOFTMMU) += null-machine.o common-obj-$(CONFIG_SOFTMMU) += loader.o common-obj-$(CONFIG_SOFTMMU) += qdev-properties-system.o +common-obj-$(CONFIG_SOFTMMU) += register.o common-obj-$(CONFIG_PLATFORM_BUS) += platform-bus.o diff --git a/hw/core/register.c b/hw/core/register.c new file mode 100644 index 0000000000..033b03c438 --- /dev/null +++ b/hw/core/register.c @@ -0,0 +1,160 @@ +/* + * Register Definition API + * + * Copyright (c) 2016 Xilinx Inc. + * Copyright (c) 2013 Peter Crosthwaite <peter.crosthwaite@xilinx.com> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * for more details. + */ + +#include "qemu/osdep.h" +#include "hw/register.h" +#include "hw/qdev.h" +#include "qemu/log.h" + +static inline void register_write_val(RegisterInfo *reg, uint64_t val) +{ + g_assert(reg->data); + + switch (reg->data_size) { + case 1: + *(uint8_t *)reg->data = val; + break; + case 2: + *(uint16_t *)reg->data = val; + break; + case 4: + *(uint32_t *)reg->data = val; + break; + case 8: + *(uint64_t *)reg->data = val; + break; + default: + g_assert_not_reached(); + } +} + +static inline uint64_t register_read_val(RegisterInfo *reg) +{ + switch (reg->data_size) { + case 1: + return *(uint8_t *)reg->data; + case 2: + return *(uint16_t *)reg->data; + case 4: + return *(uint32_t *)reg->data; + case 8: + return *(uint64_t *)reg->data; + default: + g_assert_not_reached(); + } + return 0; /* unreachable */ +} + +void register_write(RegisterInfo *reg, uint64_t val, uint64_t we, + const char *prefix, bool debug) +{ + uint64_t old_val, new_val, test, no_w_mask; + const RegisterAccessInfo *ac; + + assert(reg); + + ac = reg->access; + + if (!ac || !ac->name) { + qemu_log_mask(LOG_GUEST_ERROR, "%s: write to undefined device state " + "(written value: %#" PRIx64 ")\n", prefix, val); + return; + } + + old_val = reg->data ? register_read_val(reg) : ac->reset; + + test = (old_val ^ val) & ac->rsvd; + if (test) { + qemu_log_mask(LOG_GUEST_ERROR, "%s: change of value in reserved bit" + "fields: %#" PRIx64 ")\n", prefix, test); + } + + test = val & ac->unimp; + if (test) { + qemu_log_mask(LOG_UNIMP, + "%s:%s writing %#" PRIx64 " to unimplemented bits:" \ + " %#" PRIx64 "", + prefix, reg->access->name, val, ac->unimp); + } + + /* Create the no write mask based on the read only, write to clear and + * reserved bit masks. + */ + no_w_mask = ac->ro | ac->w1c | ac->rsvd | ~we; + new_val = (val & ~no_w_mask) | (old_val & no_w_mask); + new_val &= ~(val & ac->w1c); + + if (ac->pre_write) { + new_val = ac->pre_write(reg, new_val); + } + + if (debug) { + qemu_log("%s:%s: write of value %#" PRIx64 "\n", prefix, ac->name, + new_val); + } + + register_write_val(reg, new_val); + + if (ac->post_write) { + ac->post_write(reg, new_val); + } +} + +uint64_t register_read(RegisterInfo *reg, uint64_t re, const char* prefix, + bool debug) +{ + uint64_t ret; + const RegisterAccessInfo *ac; + + assert(reg); + + ac = reg->access; + if (!ac || !ac->name) { + qemu_log_mask(LOG_GUEST_ERROR, "%s: read from undefined device state\n", + prefix); + return 0; + } + + ret = reg->data ? register_read_val(reg) : ac->reset; + + register_write_val(reg, ret & ~(ac->cor & re)); + + /* Mask based on the read enable size */ + ret &= re; + + if (ac->post_read) { + ret = ac->post_read(reg, ret); + } + + if (debug) { + qemu_log("%s:%s: read of value %#" PRIx64 "\n", prefix, + ac->name, ret); + } + + return ret; +} + +void register_reset(RegisterInfo *reg) +{ + g_assert(reg); + + if (!reg->data || !reg->access) { + return; + } + + register_write_val(reg, reg->access->reset); +} diff --git a/include/hw/register.h b/include/hw/register.h new file mode 100644 index 0000000000..6a2bc756d1 --- /dev/null +++ b/include/hw/register.h @@ -0,0 +1,112 @@ +/* + * Register Definition API + * + * Copyright (c) 2016 Xilinx Inc. + * Copyright (c) 2013 Peter Crosthwaite <peter.crosthwaite@xilinx.com> + * + * This work is licensed under the terms of the GNU GPL, version 2. See + * the COPYING file in the top-level directory. + */ + +#ifndef REGISTER_H +#define REGISTER_H + +#include "exec/memory.h" + +typedef struct RegisterInfo RegisterInfo; +typedef struct RegisterAccessInfo RegisterAccessInfo; + +/** + * Access description for a register that is part of guest accessible device + * state. + * + * @name: String name of the register + * @ro: whether or not the bit is read-only + * @w1c: bits with the common write 1 to clear semantic. + * @reset: reset value. + * @cor: Bits that are clear on read + * @rsvd: Bits that are reserved and should not be changed + * + * @pre_write: Pre write callback. Passed the value that's to be written, + * immediately before the actual write. The returned value is what is written, + * giving the handler a chance to modify the written value. + * @post_write: Post write callback. Passed the written value. Most write side + * effects should be implemented here. + * + * @post_read: Post read callback. Passes the value that is about to be returned + * for a read. The return value from this function is what is ultimately read, + * allowing this function to modify the value before return to the client. + */ + +struct RegisterAccessInfo { + const char *name; + uint64_t ro; + uint64_t w1c; + uint64_t reset; + uint64_t cor; + uint64_t rsvd; + uint64_t unimp; + + uint64_t (*pre_write)(RegisterInfo *reg, uint64_t val); + void (*post_write)(RegisterInfo *reg, uint64_t val); + + uint64_t (*post_read)(RegisterInfo *reg, uint64_t val); +}; + +/** + * A register that is part of guest accessible state + * @data: pointer to the register data. Will be cast + * to the relevant uint type depending on data_size. + * @data_size: Size of the register in bytes. Must be + * 1, 2, 4 or 8 + * + * @access: Access description of this register + * + * @debug: Whether or not verbose debug is enabled + * @prefix: String prefix for log and debug messages + * + * @opaque: Opaque data for the register + */ + +struct RegisterInfo { + /* <public> */ + void *data; + int data_size; + + const RegisterAccessInfo *access; + + void *opaque; +}; + +/** + * write a value to a register, subject to its restrictions + * @reg: register to write to + * @val: value to write + * @we: write enable mask + * @prefix: The device prefix that should be printed before the register name + * @debug: Should the write operation debug information be printed? + */ + +void register_write(RegisterInfo *reg, uint64_t val, uint64_t we, + const char *prefix, bool debug); + +/** + * read a value from a register, subject to its restrictions + * @reg: register to read from + * @re: read enable mask + * @prefix: The device prefix that should be printed before the register name + * @debug: Should the read operation debug information be printed? + * returns: value read + */ + +uint64_t register_read(RegisterInfo *reg, uint64_t re, const char* prefix, + bool debug); + +/** + * reset a register + * @reg: register to reset + */ + +void register_reset(RegisterInfo *reg); + +#endif |