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Diffstat (limited to 'src/sys/include/arch/amd64/tss.h')
| -rw-r--r-- | src/sys/include/arch/amd64/tss.h | 149 |
1 files changed, 149 insertions, 0 deletions
diff --git a/src/sys/include/arch/amd64/tss.h b/src/sys/include/arch/amd64/tss.h new file mode 100644 index 0000000..da2059c --- /dev/null +++ b/src/sys/include/arch/amd64/tss.h @@ -0,0 +1,149 @@ +/* + * Copyright (c) 2025 Ian Marco Moffett and L5 engineers + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of the project nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + */ + +#ifndef _MACHINE_TSS_H_ +#define _MACHINE_TSS_H_ 1 + +#include <sys/types.h> +#include <sys/cdefs.h> + +#define IST_SCHED 1U + +struct pcore; + +/* + * A TSS entry (64-bit) + * + * See Intel SDM Section 8.2.1 - Task-State Segment (TSS) + */ +struct __packed tss_entry { + uint32_t reserved1; + uint32_t rsp0_lo; + uint32_t rsp0_hi; + uint32_t rsp1_lo; + uint32_t rsp1_hi; + uint32_t rsp2_lo; + uint32_t rsp2_hi; + uint64_t reserved2; + uint32_t ist1_lo; + uint32_t ist1_hi; + uint32_t ist2_lo; + uint32_t ist2_hi; + uint32_t ist3_lo; + uint32_t ist3_hi; + uint32_t ist4_lo; + uint32_t ist4_hi; + uint32_t ist5_lo; + uint32_t ist5_hi; + uint32_t ist6_lo; + uint32_t ist6_hi; + uint32_t ist7_lo; + uint32_t ist7_hi; + uint64_t reserved3; + uint16_t reserved4; + uint16_t io_base; + uint8_t iomap[8192]; +}; + +/* + * TSS descriptor (64-bit) + * + * The TSS descriptor describes the location + * of the TSS segments among other things... + * + * See Intel SDM Section 8.2.3 - TSS Descriptor in 64-bit mode + */ +struct __packed tss_desc { + uint16_t seglimit; + uint16_t base_lo16; + uint8_t base_mid8; + uint8_t type : 4; + uint8_t zero : 1; + uint8_t dpl : 2; + uint8_t p : 1; + uint8_t seglimit_hi : 4; + uint8_t avl : 1; + uint8_t unused : 2; + uint8_t g : 1; + uint8_t base_hi_mid8; + uint32_t base_hi32; + uint32_t reserved; +}; + +/* + * Holds the address of the address pointing + * to the top of an interrupt stack. + */ +union tss_stack { + struct { + uint32_t top_lo; + uint32_t top_hi; + }; + uint64_t top; +}; + +__always_inline static inline void +tss_load(void) +{ + __ASMV("str %ax\n" + "mov $0x2B, %ax\n" + "ltr %ax" + ); +} + +/* + * Allocates TSS stack. + * + * @entry_out: Result is written here + * @size: Size of new stack + * + * Returns 0 on success. + */ +int tss_alloc_stack(union tss_stack *entry_out, size_t size); + +/* + * Update interrupt stack table entry `istno' with `stack' + * + * @pcore: Current processor + * @stack: Interrupt stack. + * @istno: IST number, must be 1-based. + * + * Returns 0 on success. + */ +int tss_update_ist(struct pcore *pcore, union tss_stack stack, uint8_t istno); + +/* + * Write the TSS with a known state + * + * @pcore: Current processor + * @desc: Descriptor to initialize + */ +void write_tss(struct pcore *pcore, struct tss_desc *desc); + +#endif /* !_MACHINE_TSS_H_ */ |