diff options
| -rw-r--r-- | sys/arch/amd64/amd64/machdep.c | 19 | ||||
| -rw-r--r-- | sys/arch/amd64/amd64/simd.S | 76 |
2 files changed, 95 insertions, 0 deletions
diff --git a/sys/arch/amd64/amd64/machdep.c b/sys/arch/amd64/amd64/machdep.c index c6fb6c4..a99c4bd 100644 --- a/sys/arch/amd64/amd64/machdep.c +++ b/sys/arch/amd64/amd64/machdep.c @@ -45,6 +45,9 @@ #include <machine/cdefs.h> #include <machine/isa/i8042var.h> +#define pr_trace(fmt, ...) kprintf("cpu: " fmt, ##__VA_ARGS__) +#define pr_error(...) pr_trace(__VA_ARGS__) + #define HALT_VECTOR 0x21 #define TLB_VECTOR 0x22 @@ -55,6 +58,7 @@ #endif int ibrs_enable(void); +int simd_init(void); void syscall_isr(void); void pin_isr_load(void); @@ -155,6 +159,20 @@ backtrace_addr_to_name(uintptr_t addr, off_t *off) return NULL; } +static void +enable_simd(void) +{ + int retval; + + if ((retval = simd_init()) < 0) { + pr_error("SIMD not supported\n"); + } + + if (retval == 1) { + pr_trace("SSE enabled but not AVX\n"); + } +} + void cpu_shootdown_tlb(vaddr_t va) { @@ -290,5 +308,6 @@ cpu_startup(struct cpu_info *ci) init_tss(ci); try_mitigate_spectre(); + enable_simd(); lapic_init(); } diff --git a/sys/arch/amd64/amd64/simd.S b/sys/arch/amd64/amd64/simd.S new file mode 100644 index 0000000..23fe461 --- /dev/null +++ b/sys/arch/amd64/amd64/simd.S @@ -0,0 +1,76 @@ +/* + * Copyright (c) 2023-2025 Ian Marco Moffett and the Osmora Team. + * 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 Hyra 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. + */ + + .text + .globl simd_init +simd_init: + /* + * Enable SIMD, if SSE and AVX is supported, + * a value of zero is returned. If SSE is + * supported yet AVX is not, a value of one + * is returned. However, if none are supported, + * this routine returns -1. + */ + + // Do we support SSE? + mov $1, %eax + cpuid + bt $25, %edx + jnc .sse_not_sup + + mov %cr0, %rax // Old CR0 -> EAX + and $0xFFFB, %ax // Disable co-processor emulation + or $0x02, %ax // Enable co-processor monitoring + mov %rax, %cr0 // Update CR0 with new flags + + mov %cr4, %rax // Old CR4 -> EAX + or $0x200, %ax // Enable FXSAVE/FXRSTOR + or $0x400, %ax // Enable SIMD FP exceptions + mov %rax, %cr4 // Update CR4 with new flags + + mov $1, %eax // LEAF 1 + cpuid // Bit 28 of ECX indicates AVX support + mov $3, %eax // We need to check two bits + shl $27, %eax // Which are ECX.OSXSAVE and ECX.AVX + test %eax, %ecx // Are XSAVE and AVX supported? + jnc .avx_not_sup // Nope, just continue + + // Enable AVX + xor %rcx, %rcx // Select XCR0 + xgetbv // Load extended control register + or $0x07, %eax // Set AVX + SSE bits + xsetbv // Store new flags + xor %rax, %rax // Everything is good + retq // Return back to caller (RETURN) +.sse_not_sup: + mov $-1, %rax + retq +.avx_not_sup: + mov $1, %rax + retq |