From 98ccb3a2d41015b42d46d8b382decc755a003c3f Mon Sep 17 00:00:00 2001
From: Ian Moffett <ian@osmora.org>
Date: Tue, 4 Jun 2024 13:41:11 -0400
Subject: project: Initial commit
Signed-off-by: Ian Moffett <ian@osmora.org>
---
sys/arch/amd64/conf/GENERIC | 1 +
sys/arch/amd64/conf/link.ld | 47 +++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 48 insertions(+)
create mode 100644 sys/arch/amd64/conf/GENERIC
create mode 100644 sys/arch/amd64/conf/link.ld
(limited to 'sys/arch/amd64/conf')
diff --git a/sys/arch/amd64/conf/GENERIC b/sys/arch/amd64/conf/GENERIC
new file mode 100644
index 0000000..70b786d
--- /dev/null
+++ b/sys/arch/amd64/conf/GENERIC
@@ -0,0 +1 @@
+// TODO
diff --git a/sys/arch/amd64/conf/link.ld b/sys/arch/amd64/conf/link.ld
new file mode 100644
index 0000000..b073054
--- /dev/null
+++ b/sys/arch/amd64/conf/link.ld
@@ -0,0 +1,47 @@
+OUTPUT_FORMAT(elf64-x86-64)
+OUTPUT_ARCH(i386:x86-64)
+ENTRY(main)
+
+PHDRS
+{
+ text PT_LOAD FLAGS((1 << 0) | (1 << 2)) ; /* Execute + Read */
+ rodata PT_LOAD FLAGS((1 << 2)) ; /* Read only */
+ data PT_LOAD FLAGS((1 << 1) | (1 << 2)) ; /* Write + Read */
+}
+
+SECTIONS
+{
+ . = 0xFFFFFFFF80000000;
+
+ .text : {
+ *(.text .text.*)
+ } :text
+
+ . += CONSTANT(MAXPAGESIZE);
+
+ .rodata : {
+ *(.rodata .rodata.*)
+ } :rodata
+
+ .drivers : {
+ __drivers_init_start = .;
+ *(.drivers .drivers)
+ __drivers_init_end = .;
+ } :rodata
+
+ . += CONSTANT(MAXPAGESIZE);
+
+ .data : {
+ *(.data .data.*)
+ } :data
+
+ .bss : {
+ *(COMMON)
+ *(.bss .bss.*)
+ } :data
+
+ /DISCARD/ : {
+ *(.eh_frame)
+ *(.note .note.*)
+ }
+}
--
cgit v1.2.3
From 955d6a381f53c234ce1f4d52aa57f183ed9a6e65 Mon Sep 17 00:00:00 2001
From: Ian Moffett <ian@osmora.org>
Date: Tue, 4 Jun 2024 22:13:30 -0400
Subject: kernel/amd64: Support IBRS
Signed-off-by: Ian Moffett <ian@osmora.org>
---
sys/arch/amd64/amd64/machdep.c | 19 +++++++++++++++
sys/arch/amd64/amd64/spectre.S | 53 ++++++++++++++++++++++++++++++++++++++++++
sys/arch/amd64/conf/GENERIC | 3 ++-
sys/include/arch/amd64/msr.h | 2 ++
4 files changed, 76 insertions(+), 1 deletion(-)
create mode 100644 sys/arch/amd64/amd64/spectre.S
(limited to 'sys/arch/amd64/conf')
diff --git a/sys/arch/amd64/amd64/machdep.c b/sys/arch/amd64/amd64/machdep.c
index 19ba28a..275c23e 100644
--- a/sys/arch/amd64/amd64/machdep.c
+++ b/sys/arch/amd64/amd64/machdep.c
@@ -35,6 +35,14 @@
#include <machine/asm.h>
#include <machine/cpuid.h>
+#if defined(__SPECTRE_IBRS)
+#define SPECTRE_IBRS __SPECTRE_IBRS
+#else
+#define SPECTRE_IBRS 0
+#endif
+
+int ibrs_enable(void);
+
static struct cpu_info g_bsp_ci = {0};
static struct gdtr bsp_gdtr = {
.limit = sizeof(struct gdt_entry) * 256 - 1,
@@ -58,6 +66,16 @@ setup_vectors(void)
idt_set_desc(0xE, IDT_TRAP_GATE, ISR(page_fault), 0);
}
+static void
+try_mitigate_spectre(void)
+{
+ if (!SPECTRE_IBRS) {
+ return;
+ }
+
+ ibrs_enable();
+}
+
void
cpu_startup(void)
{
@@ -66,4 +84,5 @@ cpu_startup(void)
setup_vectors();
amd64_write_gs_base((uintptr_t)&g_bsp_ci);
+ try_mitigate_spectre();
}
diff --git a/sys/arch/amd64/amd64/spectre.S b/sys/arch/amd64/amd64/spectre.S
new file mode 100644
index 0000000..6781cbd
--- /dev/null
+++ b/sys/arch/amd64/amd64/spectre.S
@@ -0,0 +1,53 @@
+/*
+ * Copyright (c) 2023-2024 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.
+ */
+
+ #include <machine/msr.h>
+
+ .text
+ .globl ibrs_enable
+ .type ibrs_enable, @function
+ibrs_enable:
+ /* See if it is supported */
+ mov $7, %eax
+ xor %ecx, %ecx
+ cpuid
+ bt $26, %edx
+ jnc fail
+
+ /* Now we enable it */
+ mov $IA32_SPEC_CTL, %ecx
+ rdmsr
+ or $1, %eax
+ wrmsr
+ xor %rax, %rax
+ jmp 1f
+fail:
+ mov $1, %rax
+1:
+ retq
diff --git a/sys/arch/amd64/conf/GENERIC b/sys/arch/amd64/conf/GENERIC
index 70b786d..1a48a94 100644
--- a/sys/arch/amd64/conf/GENERIC
+++ b/sys/arch/amd64/conf/GENERIC
@@ -1 +1,2 @@
-// TODO
+// Kernel options
+option SPECTRE_IBRS yes
diff --git a/sys/include/arch/amd64/msr.h b/sys/include/arch/amd64/msr.h
index bc0dbcb..6ad95f1 100644
--- a/sys/include/arch/amd64/msr.h
+++ b/sys/include/arch/amd64/msr.h
@@ -33,6 +33,7 @@
#define IA32_SPEC_CTL 0x00000048
#define IA32_KERNEL_GS_BASE 0xC0000102
+#if !defined(__ASSEMBLER__)
static inline uint64_t
rdmsr(uint32_t msr_addr)
{
@@ -60,4 +61,5 @@ wrmsr(uint32_t msr_addr, uint64_t value)
);
}
+#endif /* !__ASSEMBLER__ */
#endif /* !_MACHINE_MSR_H_ */
--
cgit v1.2.3
From 433d6e282c9f1455fef07333807424f4bd07878e Mon Sep 17 00:00:00 2001
From: Ian Moffett <ian@osmora.org>
Date: Tue, 4 Jun 2024 23:28:15 -0400
Subject: kernel/amd64: spectre: Disable IBRS by default
Signed-off-by: Ian Moffett <ian@osmora.org>
---
sys/arch/amd64/conf/GENERIC | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
(limited to 'sys/arch/amd64/conf')
diff --git a/sys/arch/amd64/conf/GENERIC b/sys/arch/amd64/conf/GENERIC
index 1a48a94..ea6ba76 100644
--- a/sys/arch/amd64/conf/GENERIC
+++ b/sys/arch/amd64/conf/GENERIC
@@ -1,2 +1,2 @@
// Kernel options
-option SPECTRE_IBRS yes
+option SPECTRE_IBRS no
--
cgit v1.2.3
From f8ce8234aa7247c8f3a4317f5671b5fd40ffb8c8 Mon Sep 17 00:00:00 2001
From: Ian Moffett <ian@osmora.org>
Date: Fri, 7 Jun 2024 21:25:10 -0400
Subject: kernel: Add __cacheline_aligned macro
This commit introduces a "__cacheline_aligned" macro which aligns data
by the cache line size (COHERENCY_UNIT bytes). This is useful for
heavily contended locks.
Signed-off-by: Ian Moffett <ian@osmora.org>
---
sys/arch/amd64/conf/link.ld | 8 +++++++-
sys/include/sys/cdefs.h | 17 +++++++++++++++++
sys/include/sys/param.h | 5 +++++
3 files changed, 29 insertions(+), 1 deletion(-)
(limited to 'sys/arch/amd64/conf')
diff --git a/sys/arch/amd64/conf/link.ld b/sys/arch/amd64/conf/link.ld
index b073054..9c47a81 100644
--- a/sys/arch/amd64/conf/link.ld
+++ b/sys/arch/amd64/conf/link.ld
@@ -32,7 +32,7 @@ SECTIONS
. += CONSTANT(MAXPAGESIZE);
.data : {
- *(.data .data.*)
+ *(.data)
} :data
.bss : {
@@ -40,6 +40,12 @@ SECTIONS
*(.bss .bss.*)
} :data
+ /* -- Cache line alignment -- */
+ . = ALIGN(64);
+ .data.cacheline_aligned : {
+ *(.data.cacheline_aligned)
+ }
+
/DISCARD/ : {
*(.eh_frame)
*(.note .note.*)
diff --git a/sys/include/sys/cdefs.h b/sys/include/sys/cdefs.h
index fc21750..655a023 100644
--- a/sys/include/sys/cdefs.h
+++ b/sys/include/sys/cdefs.h
@@ -30,10 +30,27 @@
#ifndef _SYS_CDEFS_H_
#define _SYS_CDEFS_H_
+#include <sys/param.h>
+
#define __ASMV __asm__ __volatile__
#define __always_inline __attribute__((__always_inline__))
#define __packed __attribute__((__packed__))
#define __likely(exp) __builtin_expect(((exp) != 0), 1)
#define __unlikely(exp) __builtin_expect(((exp) != 0), 0)
+#if defined(_KERNEL)
+/*
+ * Align data on a cache line boundary. This is
+ * mostly useful for certain locks to ensure they
+ * have their own cache line to reduce contention.
+ *
+ */
+#ifndef __cacheline_aligned
+#define __cacheline_aligned \
+ __attribute__((__aligned__(COHERENCY_UNIT), \
+ __section__(".data.cacheline_aligned")))
+
+#endif /* __cacheline_aligned */
+#endif /* _KERNEL */
+
#endif /* !_SYS_CDEFS_H_ */
diff --git a/sys/include/sys/param.h b/sys/include/sys/param.h
index a35a094..483dc15 100644
--- a/sys/include/sys/param.h
+++ b/sys/include/sys/param.h
@@ -30,6 +30,11 @@
#ifndef _SYS_PARAM_H_
#define _SYS_PARAM_H_
+/* Assumed cache line size */
+#ifndef COHERENCY_UNIT
+#define COHERENCY_UNIT 64
+#endif
+
/* Bit related macros */
#define ISSET(v, f) ((v) & (f))
#define BIT(n) (1 << (n))
--
cgit v1.2.3
From 55845113211400c9b1657ec3ce72b06a05efac4e Mon Sep 17 00:00:00 2001
From: Ian Moffett <ian@osmora.org>
Date: Sat, 8 Jun 2024 18:19:51 -0400
Subject: kernel/amd64: Prepare for scheduler
Signed-off-by: Ian Moffett <ian@osmora.org>
---
sys/arch/amd64/amd64/lapic_intr.S | 2 +
sys/arch/amd64/amd64/mp.c | 93 ++++++++++++++++++++++++++++++++++
sys/arch/amd64/conf/GENERIC | 3 ++
sys/include/arch/amd64/cpu.h | 4 ++
sys/include/sys/proc.h | 48 ++++++++++++++++++
sys/include/sys/sched.h | 39 +++++++++++++++
sys/include/sys/schedvar.h | 63 +++++++++++++++++++++++
sys/kern/init_main.c | 5 ++
sys/kern/kern_sched.c | 102 ++++++++++++++++++++++++++++++++++++++
9 files changed, 359 insertions(+)
create mode 100644 sys/arch/amd64/amd64/mp.c
create mode 100644 sys/include/sys/proc.h
create mode 100644 sys/include/sys/sched.h
create mode 100644 sys/include/sys/schedvar.h
create mode 100644 sys/kern/kern_sched.c
(limited to 'sys/arch/amd64/conf')
diff --git a/sys/arch/amd64/amd64/lapic_intr.S b/sys/arch/amd64/amd64/lapic_intr.S
index 295de2d..a3fa7e4 100644
--- a/sys/arch/amd64/amd64/lapic_intr.S
+++ b/sys/arch/amd64/amd64/lapic_intr.S
@@ -5,5 +5,7 @@
lapic_tmr_isr:
push_trapframe $0
mov %rsp, %rdi
+ call sched_switch
+ call lapic_eoi
pop_trapframe
iretq
diff --git a/sys/arch/amd64/amd64/mp.c b/sys/arch/amd64/amd64/mp.c
new file mode 100644
index 0000000..9512aa6
--- /dev/null
+++ b/sys/arch/amd64/amd64/mp.c
@@ -0,0 +1,93 @@
+/*
+ * Copyright (c) 2023-2024 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.
+ */
+
+#include <sys/types.h>
+#include <sys/limine.h>
+#include <sys/syslog.h>
+#include <sys/spinlock.h>
+#include <sys/sched.h>
+#include <machine/cpu.h>
+#include <vm/dynalloc.h>
+#include <assert.h>
+#include <string.h>
+
+#define pr_trace(fmt, ...) kprintf("cpu_mp: " fmt, ##__VA_ARGS__)
+
+static volatile struct limine_smp_request g_smp_req = {
+ .id = LIMINE_SMP_REQUEST,
+ .revision = 0
+};
+
+static void
+ap_trampoline(struct limine_smp_info *si)
+{
+ struct spinlock lock = {0};
+ struct cpu_info *ci;
+
+ spinlock_acquire(&lock);
+ ci = dynalloc(sizeof(*ci));
+ __assert(ci != NULL);
+
+ memset(ci, 0, sizeof(*ci));
+ cpu_startup(ci);
+
+ spinlock_release(&lock);
+ sched_enter();
+
+ while (1);
+}
+
+void
+mp_bootstrap_aps(struct cpu_info *ci)
+{
+ struct limine_smp_response *resp = g_smp_req.response;
+ struct limine_smp_info **cpus;
+ size_t cpu_init_counter;
+
+ /* Should not happen */
+ __assert(resp != NULL);
+
+ cpus = resp->cpus;
+ cpu_init_counter = resp->cpu_count - 1;
+
+ if (resp->cpu_count == 1) {
+ pr_trace("CPU has 1 core, no APs to bootstrap...\n");
+ return;
+ }
+
+ pr_trace("Bootstrapping %d cores...\n", cpu_init_counter);
+ for (size_t i = 0; i < resp->cpu_count; ++i) {
+ if (ci->apicid == cpus[i]->lapic_id) {
+ pr_trace("Skip %d (BSP)... continue\n", ci->apicid);
+ continue;
+ }
+
+ cpus[i]->goto_address = ap_trampoline;
+ }
+}
diff --git a/sys/arch/amd64/conf/GENERIC b/sys/arch/amd64/conf/GENERIC
index ea6ba76..a7bbc81 100644
--- a/sys/arch/amd64/conf/GENERIC
+++ b/sys/arch/amd64/conf/GENERIC
@@ -1,2 +1,5 @@
// Kernel options
option SPECTRE_IBRS no
+
+// Kernel constants
+setval SCHED_NQUEUE 4
diff --git a/sys/include/arch/amd64/cpu.h b/sys/include/arch/amd64/cpu.h
index 84391ba..b5420a6 100644
--- a/sys/include/arch/amd64/cpu.h
+++ b/sys/include/arch/amd64/cpu.h
@@ -32,6 +32,7 @@
#include <sys/types.h>
#include <sys/cdefs.h>
+#include <sys/proc.h>
#include <machine/tss.h>
struct cpu_info {
@@ -39,10 +40,13 @@ struct cpu_info {
uint8_t has_x2apic : 1;
size_t lapic_tmr_freq;
struct tss_entry *tss;
+ struct proc *curtd;
};
void cpu_startup(struct cpu_info *ci);
struct cpu_info *this_cpu(void);
+void mp_bootstrap_aps(struct cpu_info *ci);
+
extern struct cpu_info g_bsp_ci;
#endif /* !_MACHINE_CPU_H_ */
diff --git a/sys/include/sys/proc.h b/sys/include/sys/proc.h
new file mode 100644
index 0000000..ba47a5c
--- /dev/null
+++ b/sys/include/sys/proc.h
@@ -0,0 +1,48 @@
+/*
+ * Copyright (c) 2023-2024 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.
+ */
+
+#ifndef _SYS_PROC_H_
+#define _SYS_PROC_H_
+
+#include <sys/types.h>
+#include <sys/spinlock.h>
+#if defined(_KERNEL)
+#include <machine/cpu.h>
+#include <machine/frame.h>
+#endif /* _KERNEL */
+
+#if defined(_KERNEL)
+
+struct proc {
+ pid_t pid;
+ struct cpu_info *cpu;
+};
+
+#endif /* _KERNEL */
+#endif /* !_SYS_PROC_H_ */
diff --git a/sys/include/sys/sched.h b/sys/include/sys/sched.h
new file mode 100644
index 0000000..33d546d
--- /dev/null
+++ b/sys/include/sys/sched.h
@@ -0,0 +1,39 @@
+/*
+ * Copyright (c) 2023-2024 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.
+ */
+
+#ifndef _SYS_SCHED_H_
+#define _SYS_SCHED_H_
+
+#if defined(_KERNEL)
+
+void sched_init(void);
+void sched_enter(void);
+
+#endif /* _KERNEL */
+#endif /* !_SYS_SCHED_H_ */
diff --git a/sys/include/sys/schedvar.h b/sys/include/sys/schedvar.h
new file mode 100644
index 0000000..00caeb4
--- /dev/null
+++ b/sys/include/sys/schedvar.h
@@ -0,0 +1,63 @@
+/*
+ * Copyright (c) 2023-2024 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.
+ */
+
+#ifndef _SYS_SCHEDVAR_H_
+#define _SYS_SCHEDVAR_H_
+
+#include <sys/cdefs.h>
+#include <sys/queue.h>
+#include <sys/proc.h>
+
+#if defined(_KERNEL)
+#define DEFAULT_TIMESLICE_USEC 1050
+#define SHORT_TIMESLICE_USEC 10
+
+#define SCHED_POLICY_MLFQ 0x00U /* Multilevel feedback queue */
+#define SCHED_POLICY_RR 0x01U /* Round robin */
+
+typedef uint8_t sched_policy_t;
+
+/* Might be set by kconf(1) */
+#if defined(__SCHED_NQUEUE)
+#define SCHED_NQUEUE __SCHED_NQUEUE
+#else
+#define SCHED_NQUEUE 4
+#endif /* __SCHED_NQUEUE */
+
+/* Ensure SCHED_NQUEUE is an acceptable value */
+__static_assert(SCHED_NQUEUE <= 8, "SCHED_NQUEUE exceeds max");
+__static_assert(SCHED_NQUEUE > 0, "SCHED_NQUEUE cannot be zero");
+
+struct sched_queue {
+ TAILQ_HEAD(, proc) q;
+ size_t nthread;
+};
+
+#endif /* _KERNEL */
+#endif /* !_SYS_SCHEDVAR_H_ */
diff --git a/sys/kern/init_main.c b/sys/kern/init_main.c
index 94fa8c0..6018dfe 100644
--- a/sys/kern/init_main.c
+++ b/sys/kern/init_main.c
@@ -29,6 +29,7 @@
#include <sys/reboot.h>
#include <sys/syslog.h>
+#include <sys/sched.h>
#include <dev/cons/cons.h>
#include <dev/acpi/acpi.h>
#include <machine/cpu.h>
@@ -51,6 +52,10 @@ main(void)
/* Startup the BSP */
cpu_startup(&g_bsp_ci);
+ /* Start scheduler and bootstrap APs */
+ sched_init();
+ mp_bootstrap_aps(&g_bsp_ci);
+
/* Nothing left to do... halt */
cpu_reboot(REBOOT_HALT);
__builtin_unreachable();
diff --git a/sys/kern/kern_sched.c b/sys/kern/kern_sched.c
new file mode 100644
index 0000000..b79d682
--- /dev/null
+++ b/sys/kern/kern_sched.c
@@ -0,0 +1,102 @@
+/*
+ * Copyright (c) 2023-2024 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.
+ */
+
+#include <sys/types.h>
+#include <sys/sched.h>
+#include <sys/schedvar.h>
+#include <sys/cdefs.h>
+#include <sys/syslog.h>
+#include <machine/frame.h>
+#include <dev/timer.h>
+#include <assert.h>
+
+#define pr_trace(fmt, ...) kprintf("ksched: " fmt, ##__VA_ARGS__)
+
+void sched_switch(struct trapframe *tf);
+
+static sched_policy_t policy = SCHED_POLICY_RR;
+
+/*
+ * Thread ready queues - all threads ready to be
+ * scheduled should be added to the toplevel queue.
+ */
+static struct sched_queue qlist[SCHED_NQUEUE];
+
+/*
+ * Perform timer oneshot
+ */
+static inline void
+sched_oneshot(bool now)
+{
+ struct timer timer;
+ size_t usec = now ? SHORT_TIMESLICE_USEC : DEFAULT_TIMESLICE_USEC;
+ tmrr_status_t tmr_status;
+
+ tmr_status = req_timer(TIMER_SCHED, &timer);
+ __assert(tmr_status == TMRR_SUCCESS);
+
+ timer.oneshot_us(usec);
+}
+
+/*
+ * Perform a context switch.
+ *
+ * TODO
+ */
+void
+sched_switch(struct trapframe *tf)
+{
+ static struct spinlock lock = {0};
+
+ spinlock_acquire(&lock);
+ spinlock_release(&lock);
+ sched_oneshot(false);
+}
+
+/*
+ * Main scheduler loop
+ */
+void
+sched_enter(void)
+{
+ sched_oneshot(false);
+ for (;;);
+}
+
+void
+sched_init(void)
+{
+ /* Setup the queues */
+ for (int i = 0; i < SCHED_NQUEUE; ++i) {
+ TAILQ_INIT(&qlist[i].q);
+ }
+
+ pr_trace("Prepared %d queues (policy=0x%x)\n",
+ SCHED_NQUEUE, policy);
+}
--
cgit v1.2.3