[PATCH v4 10/14] x86: Secure Launch SMP bringup support

@@ -37,6 +37,9 @@ struct real_mode_header {
 #ifdef CONFIG_X86_64
 	u32	machine_real_restart_seg;
 #endif
+#ifdef CONFIG_SECURE_LAUNCH
+	u32	sl_trampoline_start32;
+#endif
 };
 
 /* This must match data at realmode/rm/trampoline_{32,64}.S */

@@ -57,6 +57,7 @@
 #include <linux/pgtable.h>
 #include <linux/overflow.h>
 #include <linux/syscore_ops.h>
+#include <linux/slaunch.h>
 
 #include <asm/acpi.h>
 #include <asm/desc.h>

@@ -1021,6 +1022,83 @@ int common_cpu_up(unsigned int cpu, struct task_struct *idle)
 	return 0;
 }
 
+#ifdef CONFIG_SECURE_LAUNCH
+
+static atomic_t first_ap_only = {1};
+
+/*
+ * Called to fix the long jump address for the waiting APs to vector to
+ * the correct startup location in the Secure Launch stub in the rmpiggy.
+ */
+static int
+slaunch_fixup_jump_vector(void)
+{
+	struct sl_ap_wake_info *ap_wake_info;
+	u32 *ap_jmp_ptr = NULL;
+
+	if (!atomic_dec_and_test(&first_ap_only))
+		return 0;
+
+	ap_wake_info = slaunch_get_ap_wake_info();
+
+	ap_jmp_ptr = (u32 *)__va(ap_wake_info->ap_wake_block +
+				 ap_wake_info->ap_jmp_offset);
+
+	*ap_jmp_ptr = real_mode_header->sl_trampoline_start32;
+
+	pr_info("TXT AP long jump address updated\n");
+
+	return 0;
+}
+
+/*
+ * TXT AP startup is quite different than normal. The APs cannot have #INIT
+ * asserted on them or receive SIPIs. The early Secure Launch code has parked
+ * the APs in a pause loop waiting to receive an NMI. This will wake the APs
+ * and have them jump to the protected mode code in the rmpiggy where the rest
+ * of the SMP boot of the AP will proceed normally.
+ */
+static int
+slaunch_wakeup_cpu_from_txt(int cpu, int apicid)
+{
+	unsigned long send_status = 0, accept_status = 0;
+
+	/* Only done once */
+	if (slaunch_fixup_jump_vector())
+		return -1;
+
+	/* Send NMI IPI to idling AP and wake it up */
+	apic_icr_write(APIC_DM_NMI, apicid);
+
+	if (init_udelay == 0)
+		udelay(10);
+	else
+		udelay(300);
+
+	send_status = safe_apic_wait_icr_idle();
+
+	if (init_udelay == 0)
+		udelay(10);
+	else
+		udelay(300);
+
+	accept_status = (apic_read(APIC_ESR) & 0xEF);
+
+	if (send_status)
+		pr_err("Secure Launch IPI never delivered???\n");
+	if (accept_status)
+		pr_err("Secure Launch IPI delivery error (%lx)\n",
+			accept_status);
+
+	return (send_status | accept_status);
+}
+
+#else
+
+#define slaunch_wakeup_cpu_from_txt(cpu, apicid)	0
+
+#endif  /* !CONFIG_SECURE_LAUNCH */
+
 /*
  * NOTE - on most systems this is a PHYSICAL apic ID, but on multiquad
  * (ie clustered apic addressing mode), this is a LOGICAL apic ID.

@@ -1075,6 +1153,13 @@ static int do_boot_cpu(int apicid, int cpu, struct task_struct *idle,
 	cpumask_clear_cpu(cpu, cpu_initialized_mask);
 	smp_mb();
 
+	/* With Intel TXT, the AP startup is totally different */
+	if ((slaunch_get_flags() & (SL_FLAG_ACTIVE|SL_FLAG_ARCH_TXT)) ==
+	   (SL_FLAG_ACTIVE|SL_FLAG_ARCH_TXT)) {
+		boot_error = slaunch_wakeup_cpu_from_txt(cpu, apicid);
+		goto txt_wake;
+	}
+
 	/*
 	 * Wake up a CPU in difference cases:
 	 * - Use the method in the APIC driver if it's defined

@@ -1087,6 +1172,7 @@ static int do_boot_cpu(int apicid, int cpu, struct task_struct *idle,
 		boot_error = wakeup_cpu_via_init_nmi(cpu, start_ip, apicid,
 						     cpu0_nmi_registered);
 
+txt_wake:
 	if (!boot_error) {
 		/*
 		 * Wait 10s total for first sign of life from AP

@@ -36,6 +36,9 @@ SYM_DATA_START(real_mode_header)
 #ifdef CONFIG_X86_64
 	.long	__KERNEL32_CS
 #endif
+#ifdef CONFIG_SECURE_LAUNCH
+	.long	pa_sl_trampoline_start32
+#endif
 SYM_DATA_END(real_mode_header)
 
 	/* End signature, used to verify integrity */

@@ -104,6 +104,43 @@ SYM_CODE_END(sev_es_trampoline_start)
 
 	.section ".text32","ax"
 	.code32
+#ifdef CONFIG_SECURE_LAUNCH
+	.balign 4
+SYM_CODE_START(sl_trampoline_start32)
+	/*
+	 * The early secure launch stub AP wakeup code has taken care of all
+	 * the vagaries of launching out of TXT. This bit just mimics what the
+	 * 16b entry code does and jumps off to the real startup_32.
+	 */
+	cli
+	wbinvd
+
+	/*
+	 * The %ebx provided is not terribly useful since it is the physical
+	 * address of tb_trampoline_start and not the base of the image.
+	 * Use pa_real_mode_base, which is fixed up, to get a run time
+	 * base register to use for offsets to location that do not have
+	 * pa_ symbols.
+	 */
+	movl    $pa_real_mode_base, %ebx
+
+	/*
+	 * This may seem a little odd but this is what %esp would have had in
+	 * it on the jmp from real mode because all real mode fixups were done
+	 * via the code segment. The base is added at the 32b entry.
+	 */
+	movl	rm_stack_end, %esp
+
+	lgdt    tr_gdt(%ebx)
+	lidt    tr_idt(%ebx)
+
+	movw	$__KERNEL_DS, %dx	# Data segment descriptor
+
+	/* Jump to where the 16b code would have jumped */
+	ljmpl	$__KERNEL32_CS, $pa_startup_32
+SYM_CODE_END(sl_trampoline_start32)
+#endif
+
 	.balign 4
 SYM_CODE_START(startup_32)
 	movl	%edx, %ss