Merge tag 'please-pull-apei' into x86/ras

APEI is currently implemented so that it depends on x86 hardware.
The primary dependency is that GHES uses the x86 NMI for hardware
error notification and MCE for memory error handling. These patches
remove that dependency.

Other APEI features such as error reporting via external IRQ, error
serialization, or error injection, do not require changes to use them
on non-x86 architectures.

The following patch set eliminates the APEI Kconfig x86 dependency
by making these changes:
- treat NMI notification as GHES architecture - HAVE_ACPI_APEI_NMI
- group and wrap around #ifdef CONFIG_HAVE_ACPI_APEI_NMI code which
  is used only for NMI path
- identify architectural boxes and abstract it accordingly (tlb flush and MCE)
- rework ioremap for both IRQ and NMI context

NMI code is kept in ghes.c file since NMI and IRQ context are tightly coupled.

Note, these patches introduce no functional changes for x86. The NMI notification
feature is hard selected for x86. Architectures that want to use this
feature should also provide NMI code infrastructure.

1 files changed, 85 insertions, 79 deletions

diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c
index ad11ba4a412..a66ab658abb 100644
--- a/drivers/acpi/ec.c
+++ b/drivers/acpi/ec.c
@@ -1,11 +1,14 @@
 /*
- *  ec.c - ACPI Embedded Controller Driver (v2.1)
+ *  ec.c - ACPI Embedded Controller Driver (v2.2)
  *
- *  Copyright (C) 2006-2008 Alexey Starikovskiy <astarikovskiy@suse.de>
- *  Copyright (C) 2006 Denis Sadykov <denis.m.sadykov@intel.com>
- *  Copyright (C) 2004 Luming Yu <luming.yu@intel.com>
- *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
- *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
+ *  Copyright (C) 2001-2014 Intel Corporation
+ *    Author: 2014       Lv Zheng <lv.zheng@intel.com>
+ *            2006, 2007 Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>
+ *            2006       Denis Sadykov <denis.m.sadykov@intel.com>
+ *            2004       Luming Yu <luming.yu@intel.com>
+ *            2001, 2002 Andy Grover <andrew.grover@intel.com>
+ *            2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
+ *  Copyright (C) 2008      Alexey Starikovskiy <astarikovskiy@suse.de>
  *
  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  *
@@ -52,6 +55,7 @@
 /* EC status register */
 #define ACPI_EC_FLAG_OBF	0x01	/* Output buffer full */
 #define ACPI_EC_FLAG_IBF	0x02	/* Input buffer full */
+#define ACPI_EC_FLAG_CMD	0x08	/* Input buffer contains a command */
 #define ACPI_EC_FLAG_BURST	0x10	/* burst mode */
 #define ACPI_EC_FLAG_SCI	0x20	/* EC-SCI occurred */
 
@@ -78,6 +82,9 @@ enum {
 	EC_FLAGS_BLOCKED,		/* Transactions are blocked */
 };
 
+#define ACPI_EC_COMMAND_POLL		0x01 /* Available for command byte */
+#define ACPI_EC_COMMAND_COMPLETE	0x02 /* Completed last byte */
+
 /* ec.c is compiled in acpi namespace so this shows up as acpi.ec_delay param */
 static unsigned int ec_delay __read_mostly = ACPI_EC_DELAY;
 module_param(ec_delay, uint, 0644);
@@ -109,7 +116,7 @@ struct transaction {
 	u8 ri;
 	u8 wlen;
 	u8 rlen;
-	bool done;
+	u8 flags;
 };
 
 struct acpi_ec *boot_ec, *first_ec;
@@ -127,83 +134,104 @@ static int EC_FLAGS_CLEAR_ON_RESUME; /* Needs acpi_ec_clear() on boot/resume */
 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
 {
 	u8 x = inb(ec->command_addr);
-	pr_debug("---> status = 0x%2.2x\n", x);
+	pr_debug("EC_SC(R) = 0x%2.2x "
+		 "SCI_EVT=%d BURST=%d CMD=%d IBF=%d OBF=%d\n",
+		 x,
+		 !!(x & ACPI_EC_FLAG_SCI),
+		 !!(x & ACPI_EC_FLAG_BURST),
+		 !!(x & ACPI_EC_FLAG_CMD),
+		 !!(x & ACPI_EC_FLAG_IBF),
+		 !!(x & ACPI_EC_FLAG_OBF));
 	return x;
 }
 
 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
 {
 	u8 x = inb(ec->data_addr);
-	pr_debug("---> data = 0x%2.2x\n", x);
+	pr_debug("EC_DATA(R) = 0x%2.2x\n", x);
 	return x;
 }
 
 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
 {
-	pr_debug("<--- command = 0x%2.2x\n", command);
+	pr_debug("EC_SC(W) = 0x%2.2x\n", command);
 	outb(command, ec->command_addr);
 }
 
 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
 {
-	pr_debug("<--- data = 0x%2.2x\n", data);
+	pr_debug("EC_DATA(W) = 0x%2.2x\n", data);
 	outb(data, ec->data_addr);
 }
 
-static int ec_transaction_done(struct acpi_ec *ec)
+static int ec_transaction_completed(struct acpi_ec *ec)
 {
 	unsigned long flags;
 	int ret = 0;
 	spin_lock_irqsave(&ec->lock, flags);
-	if (!ec->curr || ec->curr->done)
+	if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_COMPLETE))
 		ret = 1;
 	spin_unlock_irqrestore(&ec->lock, flags);
 	return ret;
 }
 
-static void start_transaction(struct acpi_ec *ec)
+static bool advance_transaction(struct acpi_ec *ec)
 {
-	ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
-	ec->curr->done = false;
-	acpi_ec_write_cmd(ec, ec->curr->command);
-}
-
-static void advance_transaction(struct acpi_ec *ec, u8 status)
-{
-	unsigned long flags;
 	struct transaction *t;
+	u8 status;
+	bool wakeup = false;
 
-	spin_lock_irqsave(&ec->lock, flags);
+	pr_debug("===== %s =====\n", in_interrupt() ? "IRQ" : "TASK");
+	status = acpi_ec_read_status(ec);
 	t = ec->curr;
 	if (!t)
-		goto unlock;
-	if (t->wlen > t->wi) {
-		if ((status & ACPI_EC_FLAG_IBF) == 0)
-			acpi_ec_write_data(ec,
-				t->wdata[t->wi++]);
-		else
-			goto err;
-	} else if (t->rlen > t->ri) {
-		if ((status & ACPI_EC_FLAG_OBF) == 1) {
-			t->rdata[t->ri++] = acpi_ec_read_data(ec);
-			if (t->rlen == t->ri)
-				t->done = true;
+		goto err;
+	if (t->flags & ACPI_EC_COMMAND_POLL) {
+		if (t->wlen > t->wi) {
+			if ((status & ACPI_EC_FLAG_IBF) == 0)
+				acpi_ec_write_data(ec, t->wdata[t->wi++]);
+			else
+				goto err;
+		} else if (t->rlen > t->ri) {
+			if ((status & ACPI_EC_FLAG_OBF) == 1) {
+				t->rdata[t->ri++] = acpi_ec_read_data(ec);
+				if (t->rlen == t->ri) {
+					t->flags |= ACPI_EC_COMMAND_COMPLETE;
+					wakeup = true;
+				}
+			} else
+				goto err;
+		} else if (t->wlen == t->wi &&
+			   (status & ACPI_EC_FLAG_IBF) == 0) {
+			t->flags |= ACPI_EC_COMMAND_COMPLETE;
+			wakeup = true;
+		}
+		return wakeup;
+	} else {
+		if ((status & ACPI_EC_FLAG_IBF) == 0) {
+			acpi_ec_write_cmd(ec, t->command);
+			t->flags |= ACPI_EC_COMMAND_POLL;
 		} else
 			goto err;
-	} else if (t->wlen == t->wi &&
-		   (status & ACPI_EC_FLAG_IBF) == 0)
-		t->done = true;
-	goto unlock;
+		return wakeup;
+	}
 err:
 	/*
 	 * If SCI bit is set, then don't think it's a false IRQ
 	 * otherwise will take a not handled IRQ as a false one.
 	 */
-	if (in_interrupt() && !(status & ACPI_EC_FLAG_SCI))
-		++t->irq_count;
+	if (!(status & ACPI_EC_FLAG_SCI)) {
+		if (in_interrupt() && t)
+			++t->irq_count;
+	}
+	return wakeup;
+}
 
-unlock:
-	spin_unlock_irqrestore(&ec->lock, flags);
+static void start_transaction(struct acpi_ec *ec)
+{
+	ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
+	ec->curr->flags = 0;
+	(void)advance_transaction(ec);
 }
 
 static int acpi_ec_sync_query(struct acpi_ec *ec, u8 *data);
@@ -228,15 +256,17 @@ static int ec_poll(struct acpi_ec *ec)
 			/* don't sleep with disabled interrupts */
 			if (EC_FLAGS_MSI || irqs_disabled()) {
 				udelay(ACPI_EC_MSI_UDELAY);
-				if (ec_transaction_done(ec))
+				if (ec_transaction_completed(ec))
 					return 0;
 			} else {
 				if (wait_event_timeout(ec->wait,
-						ec_transaction_done(ec),
+						ec_transaction_completed(ec),
 						msecs_to_jiffies(1)))
 					return 0;
 			}
-			advance_transaction(ec, acpi_ec_read_status(ec));
+			spin_lock_irqsave(&ec->lock, flags);
+			(void)advance_transaction(ec);
+			spin_unlock_irqrestore(&ec->lock, flags);
 		} while (time_before(jiffies, delay));
 		pr_debug("controller reset, restart transaction\n");
 		spin_lock_irqsave(&ec->lock, flags);
@@ -268,23 +298,6 @@ static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
 	return ret;
 }
 
-static int ec_check_ibf0(struct acpi_ec *ec)
-{
-	u8 status = acpi_ec_read_status(ec);
-	return (status & ACPI_EC_FLAG_IBF) == 0;
-}
-
-static int ec_wait_ibf0(struct acpi_ec *ec)
-{
-	unsigned long delay = jiffies + msecs_to_jiffies(ec_delay);
-	/* interrupt wait manually if GPE mode is not active */
-	while (time_before(jiffies, delay))
-		if (wait_event_timeout(ec->wait, ec_check_ibf0(ec),
-					msecs_to_jiffies(1)))
-			return 0;
-	return -ETIME;
-}
-
 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
 {
 	int status;
@@ -305,12 +318,6 @@ static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
 			goto unlock;
 		}
 	}
-	if (ec_wait_ibf0(ec)) {
-		pr_err("input buffer is not empty, "
-				"aborting transaction\n");
-		status = -ETIME;
-		goto end;
-	}
 	pr_debug("transaction start (cmd=0x%02x, addr=0x%02x)\n",
 			t->command, t->wdata ? t->wdata[0] : 0);
 	/* disable GPE during transaction if storm is detected */
@@ -334,7 +341,6 @@ static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
 		set_bit(EC_FLAGS_GPE_STORM, &ec->flags);
 	}
 	pr_debug("transaction end\n");
-end:
 	if (ec->global_lock)
 		acpi_release_global_lock(glk);
 unlock:
@@ -634,17 +640,14 @@ static int ec_check_sci(struct acpi_ec *ec, u8 state)
 static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
 	u32 gpe_number, void *data)
 {
+	unsigned long flags;
 	struct acpi_ec *ec = data;
-	u8 status = acpi_ec_read_status(ec);
 
-	pr_debug("~~~> interrupt, status:0x%02x\n", status);
-
-	advance_transaction(ec, status);
-	if (ec_transaction_done(ec) &&
-	    (acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF) == 0) {
+	spin_lock_irqsave(&ec->lock, flags);
+	if (advance_transaction(ec))
 		wake_up(&ec->wait);
-		ec_check_sci(ec, acpi_ec_read_status(ec));
-	}
+	spin_unlock_irqrestore(&ec->lock, flags);
+	ec_check_sci(ec, acpi_ec_read_status(ec));
 	return ACPI_INTERRUPT_HANDLED | ACPI_REENABLE_GPE;
 }
 
@@ -1066,8 +1069,10 @@ int __init acpi_ec_ecdt_probe(void)
 	/* fall through */
 	}
 
-	if (EC_FLAGS_SKIP_DSDT_SCAN)
+	if (EC_FLAGS_SKIP_DSDT_SCAN) {
+		kfree(saved_ec);
 		return -ENODEV;
+	}
 
 	/* This workaround is needed only on some broken machines,
 	 * which require early EC, but fail to provide ECDT */
@@ -1105,6 +1110,7 @@ install:
 	}
 error:
 	kfree(boot_ec);
+	kfree(saved_ec);
 	boot_ec = NULL;
 	return -ENODEV;
 }