feat: added SIMD

src/kernel/archs/x86_64/asm.c

@@ -1,5 +1,21 @@
 #include "asm.h"
 
+void out8(uint16_t port, uint8_t value)
+{
+    asm volatile("outb %0, %1"
+                 :
+                 : "a"(value), "Nd"(port));
+}
+
+uint8_t in8(uint16_t port)
+{
+    uint8_t value;
+    asm volatile("inb %1, %0"
+                 : "=a"(value)
+                 : "Nd"(port));
+    return value;
+}
+
 void hal_disable_interrupts(void)
 {
     asm volatile("cli");
@@ -36,4 +52,45 @@ uint64_t asm_read_msr(uint64_t msr)
     return ((uint64_t)high << 32) | low;
 }
 
+void asm_write_xcr(uint32_t xcr, uint64_t value)
+{
+    uint32_t edx = value >> 32;
+    uint32_t eax = (uint32_t)value;
+    asm volatile("xsetbv"
+                 :
+                 : "a"(eax), "d"(edx), "c"(xcr)
+                 : "memory");
+}
 
+uint64_t asm_read_xcr(uint32_t xcr)
+{
+    uint32_t eax, edx;
+    asm volatile("xgetbv"
+                 : "=a"(eax), "=d"(edx)
+                 : "c"(xcr)
+                 : "memory");
+
+    return eax | ((uint64_t)edx << 32);
+}
+
+void asm_xsave(uint8_t *region)
+{
+    asm volatile("xsave %0" ::"m"(*region), "a"(~(uintptr_t)0), "d"(~(uintptr_t)0)
+                 : "memory");
+}
+
+void asm_xrstor(uint8_t *region)
+{
+    asm volatile("xrstor %0" ::"m"(*region), "a"(~(uintptr_t)0), "d"(~(uintptr_t)0)
+                 : "memory");
+}
+
+void asm_fxsave(void *region)
+{
+    asm volatile("fxsave (%0)" ::"a"(region));
+}
+
+void asm_fxrstor(void *region)
+{
+    asm volatile("fxrstor (%0)" ::"a"(region));
+}

src/kernel/archs/x86_64/asm.h

@@ -2,6 +2,10 @@
 
 #include <stdint.h>
 
+void out8(uint16_t port, uint8_t value);
+
+uint8_t in8(uint16_t port);
+
 #define asm_read_cr(n, reg) asm volatile("mov %%cr" #n ", %0" \
                                          : "=r"(reg))
 
@@ -31,3 +35,15 @@ enum msr_star_reg
 void asm_write_msr(uint64_t msr, uint64_t value);
 
 uint64_t asm_read_msr(uint64_t msr);
+
+void asm_write_xcr(uint32_t xcr, uint64_t value);
+
+uint64_t asm_read_xcr(uint32_t xcr);
+
+void asm_xsave(uint8_t *region);
+
+void asm_xrstor(uint8_t *region);
+
+void asm_fxrstor(void *region);
+
+void asm_fxsave(void *region);

src/kernel/archs/x86_64/cpu.h

@@ -0,0 +1,84 @@
+#pragma once
+
+#include <stdint.h>
+
+enum CRO : uint64_t
+{
+    CR0_PROTECTED_MODE = 1 << 0,
+    CR0_MONITOR_COPROCESSOR = 1 << 1,
+    CR0_EMULATION = 1 << 2,
+    CR0_TASK_SWITCHED = 1 << 3,
+    CR0_EXTENSION_TYPE = 1 << 4,
+    CR0_NUMERIC_ERROR = 1 << 5,
+    CR0_WRITE_PROTECT = 1 << 16,
+    CR0_ALIGNMENT_MASK = 1 << 18,
+    CR0_NOT_WRITE_THROUGH = 1 << 29,
+    CR0_CACHE_DISABLE = 1 << 30,
+    CR0_PAGING = 1 << 31,
+};
+
+enum CR4 : uint64_t
+{
+    CR4_VIRTUAL_MODE = 1 << 0,
+    CR4_PROTECTED_MODE_VIRTUAL_INTERRUPTS = 1 << 1,
+    CR4_TIME_STAMP_DISABLE = 1 << 2,
+    CR4_DEBUGGING_EXTENSIONS = 1 << 3,
+    CR4_PAGE_SIZE_EXTENSIONS = 1 << 4,
+    CR4_PHYSICAL_ADDRESS_EXTENSION = 1 << 5,
+    CR4_MACHINE_CHECK_ENABLE = 1 << 6,
+    CR4_PAGE_GLOBAL_ENABLE = 1 << 7,
+    CR4_PERFORMANCE_MONITORING_COUNTER_ENABLE = 1 << 8,
+    CR4_OSFXSR = 1 << 9,
+    CR4_OSXMMEXCPT_ENABLE = 1 << 10,
+    CR4_USER_MODE_INSTRUCTION_PREVENTION = 1 << 11,
+    CR4_VIRTUAL_MACHINE_EXTENSIONS = 1 << 13,
+    CR4_SAFER_MODE_EXTENSIONS = 1 << 14,
+    CR4_FGSBASE_ENABLED = 1 << 16,
+    CR4_PCIDE_ENABLE = 1 << 17,
+    CR4_OSXSAVE_ENABLE = 1 << 18,
+    CR4_SMEP_ENABLE = 1 << 20,
+    CR4_SMAP_ENABLE = 1 << 21,
+    CR4_PROTECTION_KEY_ENABLE = 1 << 22,
+    CR4_CONTROL_FLOW_ENFORCEMENT = 1 << 23,
+    CR4_PROTECTION_KEY_SUPERVISOR_PAGE = 1 << 24,
+};
+
+enum XCR0 : uint64_t
+{
+    XCR0_x87 = 1 << 0,
+    XCR0_SSE = 1 << 1,
+    XCR0_AVX = 1 << 2,
+    XCR0_BNDREGS = 1 << 3,
+    XCR0_BNDCSR = 1 << 4,
+    XCR0_OPMASK = 1 << 5,
+    XCR0_ZMM_Hi256 = 1 << 6,
+    XCR0_Hi16_ZMM = 1 << 7,
+    XCR0_PKRU = 1 << 9,
+};
+
+enum RFlags : uint64_t
+{
+    RFLAGS_CARRY = 1 << 0,
+    RFLAGS_RESERVED1 = 1 << 1,
+    RFLAGS_PARITY = 1 << 2,
+    RFLAGS_RESERVED2 = 1 << 3,
+    RFLAGS_AUXILIARY_CARRY = 1 << 4,
+    RFLAGS_RESERVED3 = 1 << 5,
+    RFLAGS_ZERO = 1 << 6,
+    RFLAGS_SIGN = 1 << 7,
+    RFLAGS_TRAP = 1 << 8,
+    RFLAGS_INTERRUPT_ENABLE = 1 << 9,
+    RFLAGS_DIRECTION = 1 << 10,
+    RFLAGS_OVERFLOW = 1 << 11,
+    RFLAGS_IO_PRIVILEGE_LEVEL = 1 << 12,
+    RFLAGS_NESTED_TASK = 1 << 14,
+    RFLAGS_RESERVED4 = 1 << 15,
+    RFLAGS_RESUME = 1 << 16,
+    RFLAGS_VIRTUAL_8086_MODE = 1 << 17,
+    RFLAGS_ALIGNMENT_CHECK = 1 << 18,
+    RFLAGS_VIRTUAL_INTERRUPT = 1 << 19,
+    RFLAGS_VIRTUAL_INTERRUPT_PENDING = 1 << 20,
+    RFLAGS_ID = 1 << 21,
+    RFLAGS_RESERVED5 = 1 << 22,
+};
+

src/kernel/archs/x86_64/cpuid.c

@@ -1,6 +1,6 @@
 #include "cpuid.h"
 
-CpuidResult cpuid(uint32_t leaf, uint32_t subleaf)
+static CpuidResult cpuid(uint32_t leaf, uint32_t subleaf)
 {
     uint32_t cpuid_max;
     CpuidResult result;
@@ -35,4 +35,45 @@ bool cpuid_has_1gb_pages(void)
     }
 
     return result.edx & CPUID_EXFEATURE_PDPE1GB;
+}
+
+bool cpuid_has_xsave(void)
+{
+    CpuidResult result = cpuid(CPUID_FEATURE_IDENTIFIER, 0);
+
+    if (!result.success)
+    {
+        return false;
+    }
+
+    return result.ecx & CPUID_XSAVE_SUPPORT;
+}
+
+bool cpuid_has_avx(void)
+{
+    CpuidResult result = cpuid(CPUID_FEATURE_IDENTIFIER, 0);
+
+    if (!result.success)
+    {
+        return false;
+    }
+
+    return result.ecx & CPUID_AVX_SUPPORT;
+}
+
+bool cpuid_has_avx512(void)
+{
+    CpuidResult result = cpuid(CPUID_EXTENDED_FEATURE_IDENTIFIER, 0);
+
+    if (!result.success)
+    {
+        return false;
+    }
+
+    return result.ebx & CPUID_AVX512_SUPPORT;
+}
+
+size_t cpuid_xsave_size(void)
+{
+    return cpuid(CPUID_PROC_EXTENDED_STATE_ENUMERATION, 0).ecx;
 }

src/kernel/archs/x86_64/cpuid.h

@@ -1,14 +1,16 @@
 #pragma once
 
+#include <stddef.h>
 #include <stdint.h>
 
-#define CPUID_EXTENDED_LEAF      (0x80000001)
+#define CPUID_EXTENDED_LEAF                   (0x80000001)
-#define CPUID_EXFEATURE_PDPE1GB  (1 << 26)
+#define CPUID_EXFEATURE_PDPE1GB               (1 << 26)
-#define CPUID_SSE_SUPPORT        (1 << 25)
+#define CPUID_XSAVE_SUPPORT                   (1 << 26)
-#define CPUID_SSE2_SUPPORT       (1 << 26)
+#define CPUID_AVX_SUPPORT                     (1 << 28)
-#define CPUID_XSAVE_SUPPORT      (1 << 26)
+#define CPUID_AVX512_SUPPORT                  (1 << 16)
-#define CPUID_FEATURE_IDENTIFIER (0x1)
+#define CPUID_FEATURE_IDENTIFIER              (0x1)
-
+#define CPUID_EXTENDED_FEATURE_IDENTIFIER     (0x7)
+#define CPUID_PROC_EXTENDED_STATE_ENUMERATION (0xD)
 typedef struct
 {
     uint32_t eax;
@@ -19,9 +21,8 @@ typedef struct
     bool success;
 } CpuidResult;
 
-CpuidResult cpuid(uint32_t leaf, uint32_t subleaf);
-
 bool cpuid_has_1gb_pages(void);
-bool cpuid_has_sse(void);
+bool cpuid_has_xsave(void);
-bool cpuid_has_sse2(void);
+bool cpuid_has_avx(void);
-bool cpuid_has_xsave(void);
+bool cpuid_has_avx512(void);
+size_t cpuid_xsave_size(void);

src/kernel/archs/x86_64/mod.c

@@ -8,6 +8,7 @@
 #include "paging.h"
 #include "hpet.h"
 #include "apic.h"
+#include "simd.h"
 
 Stream hal_dbg_stream(void)
 {
@@ -24,6 +25,7 @@ Res hal_setup(void)
     acpi_init();
     try$(hpet_init());
     try$(apic_init());
+    simd_init();
 
     return ok$();
 }

src/kernel/archs/x86_64/simd.c

@@ -0,0 +1,108 @@
+#include <dbg/log.h>
+#include <stdint.h>
+#include <string.h>
+
+#include "asm.h"
+#include "cpu.h"
+#include "cpuid.h"
+#include "simd.h"
+
+#include "../../core/pmm.h"
+
+static _Alignas(PMM_PAGE_SIZE) uint8_t simd_initial_context[PMM_PAGE_SIZE] = {};
+
+void simd_init(void)
+{
+    uint64_t cr0;
+    uint64_t cr4;
+
+    uint64_t xcr0 = XCR0_x87 | XCR0_SSE;
+    bool xcr0_compat = true;
+
+    asm_read_cr(0, cr0);
+    cr0 &= ~CR0_EMULATION;
+    cr0 |= CR0_MONITOR_COPROCESSOR;
+    cr0 |= CR0_NUMERIC_ERROR;
+    asm_write_cr(0, cr0);
+
+    asm_read_cr(4, cr4);
+    cr4 |= CR4_OSFXSR;
+    cr4 |= CR4_OSXMMEXCPT_ENABLE;
+
+    if (cpuid_has_xsave())
+    {
+        log$("XSAVE is supported");
+        cr4 |= CR4_OSXSAVE_ENABLE;
+    }
+    else
+    {
+        xcr0_compat = false;
+    }
+
+    asm_write_cr(4, cr4);
+
+    if (cpuid_has_avx())
+    {
+        log$("AVX is supported");
+        xcr0 |= XCR0_AVX;
+    }
+
+    if (cpuid_has_avx512())
+    {
+        log$("AVX512 is supported");
+        xcr0 |= XCR0_OPMASK;
+        xcr0 |= XCR0_ZMM_Hi256;
+        xcr0 |= XCR0_Hi16_ZMM;
+    }
+
+    if (xcr0_compat)
+    {
+        asm_write_xcr(0, xcr0);
+    }
+
+    asm volatile("fninit");
+    simd_context_save(simd_initial_context);
+
+    log$("SIMD initialized");
+}
+
+void simd_context_save(void *ptr)
+{
+    if (cpuid_has_xsave())
+    {
+        asm_xsave(ptr);
+    }
+    else
+    {
+        asm_fxsave(ptr);
+    }
+}
+
+size_t simd_context_size(void)
+{
+    if (cpuid_has_xsave())
+    {
+        return cpuid_xsave_size();
+    }
+    else
+    {
+        return 512;
+    }
+}
+
+void simd_context_load(void *ptr)
+{
+    if (cpuid_has_xsave())
+    {
+        asm_xrstor(ptr);
+    }
+    else
+    {
+        asm_fxrstor(ptr);
+    }
+}
+
+void simd_context_init(void *ptr)
+{
+    memcpy(ptr, simd_initial_context, simd_context_size());
+}

src/kernel/archs/x86_64/simd.h

@@ -0,0 +1,13 @@
+#pragma once
+
+#include <stddef.h>
+
+void simd_init(void);
+
+void simd_context_save(void *ptr);
+
+size_t simd_context_size(void);
+
+void simd_context_init(void *ptr);
+
+void simd_context_load(void *ptr);