[M] Change in coreboot[master]: [WIP] cpu/x86/smm: Poll for SMI delivery completion

[Kyösti Mälkki (Code Review)]

Kyösti Mälkki has uploaded this change for review. ( https://review.coreboot.org/c/coreboot/+/74741 )

Change subject: [WIP] cpu/x86/smm: Poll for SMI delivery completion
......................................................................

[WIP] cpu/x86/smm: Poll for SMI delivery completion

Change-Id: Ifc3cc23b8ec492291521319f0a2de44a45b39520
Signed-off-by: Kyösti Mälkki 
---
M src/cpu/x86/smi_trigger.c
M src/include/cpu/x86/smm.h
2 files changed, 61 insertions(+), 9 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/41/74741/1

diff --git a/src/cpu/x86/smi_trigger.c b/src/cpu/x86/smi_trigger.c
index 470ecde..cafb121 100644
--- a/src/cpu/x86/smi_trigger.c
+++ b/src/cpu/x86/smi_trigger.c
@@ -5,9 +5,11 @@
 #include <cpu/x86/smm.h>
 #include <stdint.h>

-static void apmc_log(const char *fn, u8 cmd)
+#define TIMEOUT_COUNT	100
+
+static void prepare_smi_entry(const char *fn, const u32 cmd, const u32 params, int *timeout)
 {
-	switch (cmd) {
+	switch (cmd & 0xff) {
    case APM_CNT_ACPI_DISABLE:
    	printk(BIOS_DEBUG, "%s: Disabling ACPI.\n", fn);
    	break;
@@ -18,37 +20,76 @@
    	printk(BIOS_DEBUG, "%s: Finalizing SMM.\n", fn);
    	break;
    case APM_CNT_ELOG_GSMI:
+		*timeout = TIMEOUT_COUNT;
    	break;
    case APM_CNT_SMMSTORE:
+		*timeout = TIMEOUT_COUNT;
    	break;
    case APM_CNT_SMMINFO:
    	break;
    default:
-		printk(BIOS_DEBUG, "%s: Unknown APMC 0x%02x.\n", fn, cmd);
+		printk(BIOS_ERR, "%s: Unknown APMC (eax = 0x%08x, ebx = 0x%08x)\n",
+				    fn, cmd, params);
    	break;
    }
 }

-int apm_control(u8 cmd)
+/* SMI handler is entered with commands in %eax, params in %ebx. */
+int raise_io_smi(u32 cmd, const u32 params)
 {
+	const u16 io_port = APM_CNT;
+	int set_timeout = 0, retries;
+
    /* Never proceed inside SMI handler or without one. */
    if (ENV_SMM || !CONFIG(HAVE_SMI_HANDLER))
    	return -1;

-	apmc_log(__func__, cmd);
+	prepare_smi_entry(__func__, cmd, params, &set_timeout);
+	retries = set_timeout;

/* Now raise the SMI. */
-	outb(cmd, APM_CNT);
+	__asm__ __volatile__ (
+		"	mov 	%0, %%eax\n\t"
+		"	outb 	%%al, %3\n\t"
+		"1:	cmp	%%eax, %0\n\t"
+		"	jne	3f\n\t"
+		"	test	%1, %1\n\t"
+		"	jz	3f\n\t"
+		"2:	pause\n\t"
+		"	dec	%1\n\t"
+		"	jmp	1b\n\t"
+		"3:\n\t"
+		: "+r" (cmd), "+r" (retries)
+		: "b" (params), "d" (io_port)
+		: "%eax", "memory");

-	printk(BIOS_DEBUG, "APMC done.\n");
+	if (!set_timeout) {
+		printk(BIOS_DEBUG, "APMC done.\n");
+		return 0;
+	}
+
+	if (cmd & 0xff) {
+		printk(BIOS_ERR, "APMC timed out (%d latency).\n", set_timeout - retries);
+		return -1;
+	}
+
+	printk(BIOS_DEBUG, "APMC done (%d latency).\n", set_timeout - retries);
    return 0;
 }

+void apm_control(u8 cmd)
+{
+	/* Now raise the SMI. */
+	raise_io_smi(cmd, 0);
+}
+
 u8 apm_get_apmc(void)
 {
+	int timeout_dummy;
+
    /* Emulate B2 register as the FADT / Linux expects it */
    u8 cmd = inb(APM_CNT);

-	apmc_log("SMI#", cmd);
+	prepare_smi_entry("SMI#", cmd, 0, &timeout_dummy);
    return cmd;
 }
diff --git a/src/include/cpu/x86/smm.h b/src/include/cpu/x86/smm.h
index 4c97f21..667b17a 100644
--- a/src/include/cpu/x86/smm.h
+++ b/src/include/cpu/x86/smm.h
@@ -34,7 +34,8 @@
 #define SMM_PCI_RESOURCE_STORE_NUM_RESOURCES 6

/* Send cmd to APM_CNT with HAVE_SMI_HANDLER checking. */
-int apm_control(u8 cmd);
+int raise_io_smi(u32 cmd, const u32 params);
+void apm_control(u8 cmd);
 u8 apm_get_apmc(void);

void io_trap_handler(int smif);