1 files changed, 148 insertions, 0 deletions
diff --git a/roms/seabios/src/fw/smp.c b/roms/seabios/src/fw/smp.c
new file mode 100644
index 000000000..38fe383af
--- /dev/null
+++ b/roms/seabios/src/fw/smp.c
@@ -0,0 +1,148 @@
+// CPU count detection
+//
+// Copyright (C) 2008  Kevin O'Connor <kevin@koconnor.net>
+// Copyright (C) 2006 Fabrice Bellard
+//
+// This file may be distributed under the terms of the GNU LGPLv3 license.
+
+#include "config.h" // CONFIG_*
+#include "hw/rtc.h" // CMOS_BIOS_SMP_COUNT
+#include "output.h" // dprintf
+#include "romfile.h" // romfile_loadint
+#include "stacks.h" // yield
+#include "util.h" // smp_setup
+#include "x86.h" // wrmsr
+
+#define APIC_ICR_LOW ((u8*)BUILD_APIC_ADDR + 0x300)
+#define APIC_SVR     ((u8*)BUILD_APIC_ADDR + 0x0F0)
+#define APIC_LINT0   ((u8*)BUILD_APIC_ADDR + 0x350)
+#define APIC_LINT1   ((u8*)BUILD_APIC_ADDR + 0x360)
+
+#define APIC_ENABLED 0x0100
+
+struct { u32 ecx, eax, edx; } smp_mtrr[32] VARFSEG;
+u32 smp_mtrr_count VARFSEG;
+
+void
+wrmsr_smp(u32 index, u64 val)
+{
+    wrmsr(index, val);
+    if (smp_mtrr_count >= ARRAY_SIZE(smp_mtrr)) {
+        warn_noalloc();
+        return;
+    }
+    smp_mtrr[smp_mtrr_count].ecx = index;
+    smp_mtrr[smp_mtrr_count].eax = val;
+    smp_mtrr[smp_mtrr_count].edx = val >> 32;
+    smp_mtrr_count++;
+}
+
+u32 CountCPUs VARFSEG;
+u32 MaxCountCPUs;
+// 256 bits for the found APIC IDs
+u32 FoundAPICIDs[256/32] VARFSEG;
+extern void smp_ap_boot_code(void);
+ASM16(
+    "  .global smp_ap_boot_code\n"
+    "smp_ap_boot_code:\n"
+
+    // Setup data segment
+    "  movw $" __stringify(SEG_BIOS) ", %ax\n"
+    "  movw %ax, %ds\n"
+
+    // MTRR setup
+    "  movl $smp_mtrr, %esi\n"
+    "  movl smp_mtrr_count, %ebx\n"
+    "1:testl %ebx, %ebx\n"
+    "  jz 2f\n"
+    "  movl 0(%esi), %ecx\n"
+    "  movl 4(%esi), %eax\n"
+    "  movl 8(%esi), %edx\n"
+    "  wrmsr\n"
+    "  addl $12, %esi\n"
+    "  decl %ebx\n"
+    "  jmp 1b\n"
+    "2:\n"
+
+    // get apic ID on EBX, set bit on FoundAPICIDs
+    "  movl $1, %eax\n"
+    "  cpuid\n"
+    "  shrl $24, %ebx\n"
+    "  lock btsl %ebx, FoundAPICIDs\n"
+
+    // Increment the cpu counter
+    "  lock incl CountCPUs\n"
+
+    // Halt the processor.
+    "1:hlt\n"
+    "  jmp 1b\n"
+    );
+
+int apic_id_is_present(u8 apic_id)
+{
+    return !!(FoundAPICIDs[apic_id/32] & (1ul << (apic_id % 32)));
+}
+
+// find and initialize the CPUs by launching a SIPI to them
+void
+smp_setup(void)
+{
+    if (!CONFIG_QEMU)
+        return;
+
+    ASSERT32FLAT();
+    u32 eax, ebx, ecx, cpuid_features;
+    cpuid(1, &eax, &ebx, &ecx, &cpuid_features);
+    if (eax < 1 || !(cpuid_features & CPUID_APIC)) {
+        // No apic - only the main cpu is present.
+        dprintf(1, "No apic - only the main cpu is present.\n");
+        CountCPUs= 1;
+        MaxCountCPUs = 1;
+        return;
+    }
+
+    // mark the BSP initial APIC ID as found, too:
+    u8 apic_id = ebx>>24;
+    FoundAPICIDs[apic_id/32] |= (1 << (apic_id % 32));
+
+    // Init the counter.
+    writel(&CountCPUs, 1);
+
+    // Setup jump trampoline to counter code.
+    u64 old = *(u64*)BUILD_AP_BOOT_ADDR;
+    // ljmpw $SEG_BIOS, $(smp_ap_boot_code - BUILD_BIOS_ADDR)
+    u64 new = (0xea | ((u64)SEG_BIOS<<24)
+               | (((u32)smp_ap_boot_code - BUILD_BIOS_ADDR) << 8));
+    *(u64*)BUILD_AP_BOOT_ADDR = new;
+
+    // enable local APIC
+    u32 val = readl(APIC_SVR);
+    writel(APIC_SVR, val | APIC_ENABLED);
+
+    /* Set LINT0 as Ext_INT, level triggered */
+    writel(APIC_LINT0, 0x8700);
+
+    /* Set LINT1 as NMI, level triggered */
+    writel(APIC_LINT1, 0x8400);
+
+    // broadcast SIPI
+    barrier();
+    writel(APIC_ICR_LOW, 0x000C4500);
+    u32 sipi_vector = BUILD_AP_BOOT_ADDR >> 12;
+    writel(APIC_ICR_LOW, 0x000C4600 | sipi_vector);
+
+    // Wait for other CPUs to process the SIPI.
+    u8 cmos_smp_count = rtc_read(CMOS_BIOS_SMP_COUNT);
+    while (cmos_smp_count + 1 != readl(&CountCPUs))
+        yield();
+
+    // Restore memory.
+    *(u64*)BUILD_AP_BOOT_ADDR = old;
+
+    MaxCountCPUs = romfile_loadint("etc/max-cpus", 0);
+    if (!MaxCountCPUs || MaxCountCPUs < CountCPUs)
+        MaxCountCPUs = CountCPUs;
+
+    dprintf(1, "Found %d cpu(s) max supported %d cpu(s)\n", readl(&CountCPUs),
+        MaxCountCPUs);
+}