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-rw-r--r--sys/arch/amd64/gdt.c5
-rw-r--r--sys/arch/amd64/machdep.c19
-rw-r--r--sys/arch/amd64/tss.S41
-rw-r--r--sys/arch/amd64/tss.c82
-rw-r--r--sys/include/arch/amd64/cpu.h2
-rw-r--r--sys/include/arch/amd64/gdt.h1
-rw-r--r--sys/include/arch/amd64/tss.h106
7 files changed, 256 insertions, 0 deletions
diff --git a/sys/arch/amd64/gdt.c b/sys/arch/amd64/gdt.c
index 209e2f7..667170a 100644
--- a/sys/arch/amd64/gdt.c
+++ b/sys/arch/amd64/gdt.c
@@ -72,8 +72,13 @@ struct gdt_entry g_gdt[256] = {
.granularity = 0x00,
.base_hi = 0x00
},
+
+ /* TSS segment (0x28) */
+ {0}
};
+struct gdt_entry *g_gdt_tss = &g_gdt[GDT_TSS];
+
struct gdtr g_gdtr = {
.limit = sizeof(struct gdt_entry) * 256 - 1,
.offset = (uintptr_t)&g_gdt[0]
diff --git a/sys/arch/amd64/machdep.c b/sys/arch/amd64/machdep.c
index 3f3feb0..a466d38 100644
--- a/sys/arch/amd64/machdep.c
+++ b/sys/arch/amd64/machdep.c
@@ -34,6 +34,7 @@
#include <machine/gdt.h>
#include <machine/ioapic.h>
#include <machine/lapic.h>
+#include <machine/tss.h>
#include <machine/spectre.h>
#include <machine/cpu.h>
@@ -44,6 +45,16 @@ __KERNEL_META("$Hyra$: machdep.c, Ian Marco Moffett, "
#define ISR(func) ((uintptr_t)func)
#define INIT_FLAG_IOAPIC 0x00000001U
+static inline void
+init_tss(struct cpu_info *cur_cpu)
+{
+ struct tss_desc *desc;
+
+ desc = (struct tss_desc *)g_gdt_tss;
+ write_tss(cur_cpu, desc);
+ tss_load();
+}
+
static void
interrupts_init(void)
{
@@ -73,6 +84,8 @@ processor_init(void)
/* Indicates what doesn't need to be init anymore */
static uint8_t init_flags = 0;
+ struct cpu_info *cur_cpu = NULL;
+
interrupts_init();
gdt_load(&g_gdtr);
@@ -82,6 +95,12 @@ processor_init(void)
}
lapic_init(); /* Per core */
+ cur_cpu = this_cpu();
+
+ CPU_INFO_LOCK(cur_cpu);
+ cur_cpu->tss = NULL;
+ init_tss(cur_cpu);
+ CPU_INFO_UNLOCK(cur_cpu);
/* Enable spectre mitigation if enabled */
if (try_spectre_mitigate != NULL)
diff --git a/sys/arch/amd64/tss.S b/sys/arch/amd64/tss.S
new file mode 100644
index 0000000..be44a04
--- /dev/null
+++ b/sys/arch/amd64/tss.S
@@ -0,0 +1,41 @@
+/*
+ * Copyright (c) 2023 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/cdefs.h>
+
+__KERNEL_META "$Hyra$: tss.S, Ian Marco Moffett, \
+ Low level TSS code"
+
+.globl tss_load
+tss_load:
+ str %ax /* Store task register value into AX */
+ mov $0x28, %ax /* Store TSS GDT selector into AX */
+ or $3, %ax
+ ltr %ax /* Load the task register */
+ retq
diff --git a/sys/arch/amd64/tss.c b/sys/arch/amd64/tss.c
new file mode 100644
index 0000000..3463291
--- /dev/null
+++ b/sys/arch/amd64/tss.c
@@ -0,0 +1,82 @@
+/*
+ * Copyright (c) 2023 Ian Marco Moffett and the Osmora Team.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of Hyra nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <machine/tss.h>
+#include <machine/cpu.h>
+#include <lib/string.h>
+#include <vm/dynalloc.h>
+#include <sys/panic.h>
+
+__MODULE_NAME("TSS");
+__KERNEL_META("$Hyra$: tss.c, Ian Marco Moffett, "
+ "AMD64 Task state segment code");
+
+static void
+alloc_resources(struct cpu_info *cpu)
+{
+ struct tss_entry *tss;
+
+ /*
+ * Allocate TSS entries for this CPU
+ */
+ if (cpu->tss == NULL) {
+ /* Allocate a TSS for this CPU */
+ tss = dynalloc(sizeof(*tss));
+ if (tss == NULL)
+ panic("Failed to alloc %d bytes for TSS\n", sizeof(*tss));
+ memset(tss, 0, sizeof(*tss));
+ cpu->tss = tss;
+ }
+}
+
+void
+write_tss(struct cpu_info *cpu, struct tss_desc *desc)
+{
+ uintptr_t tss_base;
+
+ alloc_resources(cpu);
+
+ tss_base = (uintptr_t)cpu->tss;
+
+ /*
+ * XXX: The AVL (Available for use by system software)
+ * bit is ignored by hardware and it is up to us
+ * to decide how to use it... As of now, it is useless
+ * to us and shall remain 0.
+ */
+ desc->p = 1; /* Must be present to be valid! */
+ desc->g = 0; /* Granularity -> 0 */
+ desc->avl = 0; /* Not used */
+ desc->dpl = 0; /* Descriptor Privilege Level -> 0 */
+ desc->type = 0x9; /* For TSS -> 0x9 (0b1001) */
+
+ desc->base_lo16 = __SHIFTOUT(tss_base, __MASK(16));
+ desc->base_mid24 = __SHIFTOUT(tss_base, __MASK(8) << 24);
+ desc->base_mid32 = __SHIFTOUT(tss_base, __MASK(32) << 32);
+}
diff --git a/sys/include/arch/amd64/cpu.h b/sys/include/arch/amd64/cpu.h
index e93e8a2..9645aac 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/spinlock.h>
+#include <machine/tss.h>
#define this_cpu() amd64_this_cpu()
#define get_bsp() amd64_get_bsp()
@@ -53,6 +54,7 @@ struct cpu_info {
/* AMD64 */
volatile size_t lapic_tmr_freq;
+ volatile struct tss_entry *tss;
};
struct cpu_info *amd64_this_cpu(void);
diff --git a/sys/include/arch/amd64/gdt.h b/sys/include/arch/amd64/gdt.h
index e5a7492..2521627 100644
--- a/sys/include/arch/amd64/gdt.h
+++ b/sys/include/arch/amd64/gdt.h
@@ -73,6 +73,7 @@ gdt_load(struct gdtr *gdtr)
}
extern struct gdt_entry g_gdt[256];
+extern struct gdt_entry *g_gdt_tss;
extern struct gdtr g_gdtr;
#endif /* !AMD64_GDT_H_ */
diff --git a/sys/include/arch/amd64/tss.h b/sys/include/arch/amd64/tss.h
new file mode 100644
index 0000000..502cf9e
--- /dev/null
+++ b/sys/include/arch/amd64/tss.h
@@ -0,0 +1,106 @@
+/*
+ * Copyright (c) 2023 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 _AMD64_TSS_H_
+#define _AMD64_TSS_H_
+
+#include <sys/types.h>
+#include <sys/cdefs.h>
+
+/*
+ * cpu_info is from machine/cpu.h
+ *
+ * XXX: machine/cpu.h includes this header
+ * so we must create this as including
+ * machine/cpu.h will not do anything...
+ */
+struct cpu_info;
+
+/*
+ * 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;
+};
+
+/*
+ * 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_mid24;
+ 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_mid32;
+ uint32_t base_hi32;
+ uint32_t reserved;
+};
+
+void write_tss(struct cpu_info *cpu, struct tss_desc *desc);
+void tss_load(void); /* In tss.S */
+
+#endif /* _!_AMD64_TSS_H_ */
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-23 00:21:14 +0000