Merge branches 'acpi-processor' and 'acpi-cppc'

* acpi-processor:
  ACPI / sleep: move acpi_processor_sleep to sleep.c
  ACPI / processor : add support for ACPI0010 processor container
  ACPI / processor_idle: replace PREFIX with pr_fmt

* acpi-cppc:
  ACPI / CPPC: use MRTT/MPAR to decide if/when a req can be sent
  ACPI / CPPC: replace writeX/readX to PCC with relaxed version
  mailbox: pcc: optimized pcc_send_data
  ACPI / CPPC: optimized cpc_read and cpc_write
  ACPI / CPPC: Optimize PCC Read Write operations

drivers/acpi/acpi_processor.c

@@ -514,7 +514,24 @@ static struct acpi_scan_handler processor_handler = {
 	},
 };
 
+static int acpi_processor_container_attach(struct acpi_device *dev,
+					   const struct acpi_device_id *id)
+{
+	return 1;
+}
+
+static const struct acpi_device_id processor_container_ids[] = {
+	{ ACPI_PROCESSOR_CONTAINER_HID, },
+	{ }
+};
+
+static struct acpi_scan_handler processor_container_handler = {
+	.ids = processor_container_ids,
+	.attach = acpi_processor_container_attach,
+};
+
 void __init acpi_processor_init(void)
 {
 	acpi_scan_add_handler_with_hotplug(&processor_handler, "processor");
+	acpi_scan_add_handler(&processor_container_handler);
 }

drivers/acpi/cppc_acpi.c

@@ -39,6 +39,7 @@
 
 #include <linux/cpufreq.h>
 #include <linux/delay.h>
+#include <linux/ktime.h>
 
 #include <acpi/cppc_acpi.h>
 /*
@@ -63,58 +64,140 @@ static struct mbox_chan *pcc_channel;
 static void __iomem *pcc_comm_addr;
 static u64 comm_base_addr;
 static int pcc_subspace_idx = -1;
-static u16 pcc_cmd_delay;
 static bool pcc_channel_acquired;
+static ktime_t deadline;
+static unsigned int pcc_mpar, pcc_mrtt;
+
+/* pcc mapped address + header size + offset within PCC subspace */
+#define GET_PCC_VADDR(offs) (pcc_comm_addr + 0x8 + (offs))
 
 /*
  * Arbitrary Retries in case the remote processor is slow to respond
- * to PCC commands.
+ * to PCC commands. Keeping it high enough to cover emulators where
+ * the processors run painfully slow.
  */
 #define NUM_RETRIES 500
 
+static int check_pcc_chan(void)
+{
+	int ret = -EIO;
+	struct acpi_pcct_shared_memory __iomem *generic_comm_base = pcc_comm_addr;
+	ktime_t next_deadline = ktime_add(ktime_get(), deadline);
+
+	/* Retry in case the remote processor was too slow to catch up. */
+	while (!ktime_after(ktime_get(), next_deadline)) {
+		/*
+		 * Per spec, prior to boot the PCC space wil be initialized by
+		 * platform and should have set the command completion bit when
+		 * PCC can be used by OSPM
+		 */
+		if (readw_relaxed(&generic_comm_base->status) & PCC_CMD_COMPLETE) {
+			ret = 0;
+			break;
+		}
+		/*
+		 * Reducing the bus traffic in case this loop takes longer than
+		 * a few retries.
+		 */
+		udelay(3);
+	}
+
+	return ret;
+}
+
 static int send_pcc_cmd(u16 cmd)
 {
-	int retries, result = -EIO;
-	struct acpi_pcct_hw_reduced *pcct_ss = pcc_channel->con_priv;
+	int ret = -EIO;
 	struct acpi_pcct_shared_memory *generic_comm_base =
 		(struct acpi_pcct_shared_memory *) pcc_comm_addr;
-	u32 cmd_latency = pcct_ss->latency;
+	static ktime_t last_cmd_cmpl_time, last_mpar_reset;
+	static int mpar_count;
+	unsigned int time_delta;
+
+	/*
+	 * For CMD_WRITE we know for a fact the caller should have checked
+	 * the channel before writing to PCC space
+	 */
+	if (cmd == CMD_READ) {
+		ret = check_pcc_chan();
+		if (ret)
+			return ret;
+	}
 
-	/* Min time OS should wait before sending next command. */
-	udelay(pcc_cmd_delay);
+	/*
+	 * Handle the Minimum Request Turnaround Time(MRTT)
+	 * "The minimum amount of time that OSPM must wait after the completion
+	 * of a command before issuing the next command, in microseconds"
+	 */
+	if (pcc_mrtt) {
+		time_delta = ktime_us_delta(ktime_get(), last_cmd_cmpl_time);
+		if (pcc_mrtt > time_delta)
+			udelay(pcc_mrtt - time_delta);
+	}
+
+	/*
+	 * Handle the non-zero Maximum Periodic Access Rate(MPAR)
+	 * "The maximum number of periodic requests that the subspace channel can
+	 * support, reported in commands per minute. 0 indicates no limitation."
+	 *
+	 * This parameter should be ideally zero or large enough so that it can
+	 * handle maximum number of requests that all the cores in the system can
+	 * collectively generate. If it is not, we will follow the spec and just
+	 * not send the request to the platform after hitting the MPAR limit in
+	 * any 60s window
+	 */
+	if (pcc_mpar) {
+		if (mpar_count == 0) {
+			time_delta = ktime_ms_delta(ktime_get(), last_mpar_reset);
+			if (time_delta < 60 * MSEC_PER_SEC) {
+				pr_debug("PCC cmd not sent due to MPAR limit");
+				return -EIO;
+			}
+			last_mpar_reset = ktime_get();
+			mpar_count = pcc_mpar;
+		}
+		mpar_count--;
+	}
 
 	/* Write to the shared comm region. */
-	writew(cmd, &generic_comm_base->command);
+	writew_relaxed(cmd, &generic_comm_base->command);
 
 	/* Flip CMD COMPLETE bit */
-	writew(0, &generic_comm_base->status);
+	writew_relaxed(0, &generic_comm_base->status);
 
 	/* Ring doorbell */
-	result = mbox_send_message(pcc_channel, &cmd);
-	if (result < 0) {
+	ret = mbox_send_message(pcc_channel, &cmd);
+	if (ret < 0) {
 		pr_err("Err sending PCC mbox message. cmd:%d, ret:%d\n",
-				cmd, result);
-		return result;
+				cmd, ret);
+		return ret;
 	}
 
-	/* Wait for a nominal time to let platform process command. */
-	udelay(cmd_latency);
-
-	/* Retry in case the remote processor was too slow to catch up. */
-	for (retries = NUM_RETRIES; retries > 0; retries--) {
-		if (readw_relaxed(&generic_comm_base->status) & PCC_CMD_COMPLETE) {
-			result = 0;
-			break;
-		}
+	/*
+	 * For READs we need to ensure the cmd completed to ensure
+	 * the ensuing read()s can proceed. For WRITEs we dont care
+	 * because the actual write()s are done before coming here
+	 * and the next READ or WRITE will check if the channel
+	 * is busy/free at the entry of this call.
+	 *
+	 * If Minimum Request Turnaround Time is non-zero, we need
+	 * to record the completion time of both READ and WRITE
+	 * command for proper handling of MRTT, so we need to check
+	 * for pcc_mrtt in addition to CMD_READ
+	 */
+	if (cmd == CMD_READ || pcc_mrtt) {
+		ret = check_pcc_chan();
+		if (pcc_mrtt)
+			last_cmd_cmpl_time = ktime_get();
 	}
 
-	mbox_client_txdone(pcc_channel, result);
-	return result;
+	mbox_client_txdone(pcc_channel, ret);
+	return ret;
 }
 
 static void cppc_chan_tx_done(struct mbox_client *cl, void *msg, int ret)
 {
-	if (ret)
+	if (ret < 0)
 		pr_debug("TX did not complete: CMD sent:%x, ret:%d\n",
 				*(u16 *)msg, ret);
 	else
@@ -306,6 +389,7 @@ static int register_pcc_channel(int pcc_subspace_idx)
 {
 	struct acpi_pcct_hw_reduced *cppc_ss;
 	unsigned int len;
+	u64 usecs_lat;
 
 	if (pcc_subspace_idx >= 0) {
 		pcc_channel = pcc_mbox_request_channel(&cppc_mbox_cl,
@@ -335,7 +419,16 @@ static int register_pcc_channel(int pcc_subspace_idx)
 		 */
 		comm_base_addr = cppc_ss->base_address;
 		len = cppc_ss->length;
-		pcc_cmd_delay = cppc_ss->min_turnaround_time;
+
+		/*
+		 * cppc_ss->latency is just a Nominal value. In reality
+		 * the remote processor could be much slower to reply.
+		 * So add an arbitrary amount of wait on top of Nominal.
+		 */
+		usecs_lat = NUM_RETRIES * cppc_ss->latency;
+		deadline = ns_to_ktime(usecs_lat * NSEC_PER_USEC);
+		pcc_mrtt = cppc_ss->min_turnaround_time;
+		pcc_mpar = cppc_ss->max_access_rate;
 
 		pcc_comm_addr = acpi_os_ioremap(comm_base_addr, len);
 		if (!pcc_comm_addr) {
@@ -546,29 +639,74 @@ void acpi_cppc_processor_exit(struct acpi_processor *pr)
 }
 EXPORT_SYMBOL_GPL(acpi_cppc_processor_exit);
 
-static u64 get_phys_addr(struct cpc_reg *reg)
-{
-	/* PCC communication addr space begins at byte offset 0x8. */
-	if (reg->space_id == ACPI_ADR_SPACE_PLATFORM_COMM)
-		return (u64)comm_base_addr + 0x8 + reg->address;
-	else
-		return reg->address;
-}
+/*
+ * Since cpc_read and cpc_write are called while holding pcc_lock, it should be
+ * as fast as possible. We have already mapped the PCC subspace during init, so
+ * we can directly write to it.
+ */
 
-static void cpc_read(struct cpc_reg *reg, u64 *val)
+static int cpc_read(struct cpc_reg *reg, u64 *val)
 {
-	u64 addr = get_phys_addr(reg);
+	int ret_val = 0;
 
-	acpi_os_read_memory((acpi_physical_address)addr,
+	*val = 0;
+	if (reg->space_id == ACPI_ADR_SPACE_PLATFORM_COMM) {
+		void __iomem *vaddr = GET_PCC_VADDR(reg->address);
+
+		switch (reg->bit_width) {
+		case 8:
+			*val = readb_relaxed(vaddr);
+			break;
+		case 16:
+			*val = readw_relaxed(vaddr);
+			break;
+		case 32:
+			*val = readl_relaxed(vaddr);
+			break;
+		case 64:
+			*val = readq_relaxed(vaddr);
+			break;
+		default:
+			pr_debug("Error: Cannot read %u bit width from PCC\n",
+				reg->bit_width);
+			ret_val = -EFAULT;
+		}
+	} else
+		ret_val = acpi_os_read_memory((acpi_physical_address)reg->address,
 					val, reg->bit_width);
+	return ret_val;
 }
 
-static void cpc_write(struct cpc_reg *reg, u64 val)
+static int cpc_write(struct cpc_reg *reg, u64 val)
 {
-	u64 addr = get_phys_addr(reg);
+	int ret_val = 0;
+
+	if (reg->space_id == ACPI_ADR_SPACE_PLATFORM_COMM) {
+		void __iomem *vaddr = GET_PCC_VADDR(reg->address);
 
-	acpi_os_write_memory((acpi_physical_address)addr,
+		switch (reg->bit_width) {
+		case 8:
+			writeb_relaxed(val, vaddr);
+			break;
+		case 16:
+			writew_relaxed(val, vaddr);
+			break;
+		case 32:
+			writel_relaxed(val, vaddr);
+			break;
+		case 64:
+			writeq_relaxed(val, vaddr);
+			break;
+		default:
+			pr_debug("Error: Cannot write %u bit width to PCC\n",
+				reg->bit_width);
+			ret_val = -EFAULT;
+			break;
+		}
+	} else
+		ret_val = acpi_os_write_memory((acpi_physical_address)reg->address,
 				val, reg->bit_width);
+	return ret_val;
 }
 
 /**
@@ -604,7 +742,7 @@ int cppc_get_perf_caps(int cpunum, struct cppc_perf_caps *perf_caps)
 			(ref_perf->cpc_entry.reg.space_id == ACPI_ADR_SPACE_PLATFORM_COMM) ||
 			(nom_perf->cpc_entry.reg.space_id == ACPI_ADR_SPACE_PLATFORM_COMM)) {
 		/* Ring doorbell once to update PCC subspace */
-		if (send_pcc_cmd(CMD_READ)) {
+		if (send_pcc_cmd(CMD_READ) < 0) {
 			ret = -EIO;
 			goto out_err;
 		}
@@ -662,7 +800,7 @@ int cppc_get_perf_ctrs(int cpunum, struct cppc_perf_fb_ctrs *perf_fb_ctrs)
 	if ((delivered_reg->cpc_entry.reg.space_id == ACPI_ADR_SPACE_PLATFORM_COMM) ||
 			(reference_reg->cpc_entry.reg.space_id == ACPI_ADR_SPACE_PLATFORM_COMM)) {
 		/* Ring doorbell once to update PCC subspace */
-		if (send_pcc_cmd(CMD_READ)) {
+		if (send_pcc_cmd(CMD_READ) < 0) {
 			ret = -EIO;
 			goto out_err;
 		}
@@ -713,6 +851,13 @@ int cppc_set_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls)
 
 	spin_lock(&pcc_lock);
 
+	/* If this is PCC reg, check if channel is free before writing */
+	if (desired_reg->cpc_entry.reg.space_id == ACPI_ADR_SPACE_PLATFORM_COMM) {
+		ret = check_pcc_chan();
+		if (ret)
+			goto busy_channel;
+	}
+
 	/*
 	 * Skip writing MIN/MAX until Linux knows how to come up with
 	 * useful values.
@@ -722,10 +867,10 @@ int cppc_set_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls)
 	/* Is this a PCC reg ?*/
 	if (desired_reg->cpc_entry.reg.space_id == ACPI_ADR_SPACE_PLATFORM_COMM) {
 		/* Ring doorbell so Remote can get our perf request. */
-		if (send_pcc_cmd(CMD_WRITE))
+		if (send_pcc_cmd(CMD_WRITE) < 0)
 			ret = -EIO;
 	}
-
+busy_channel:
 	spin_unlock(&pcc_lock);
 
 	return ret;

drivers/acpi/processor_driver.c

@@ -314,7 +314,6 @@ static int __init acpi_processor_driver_init(void)
 	if (result < 0)
 		return result;
 
-	acpi_processor_syscore_init();
 	register_hotcpu_notifier(&acpi_cpu_notifier);
 	acpi_thermal_cpufreq_init();
 	acpi_processor_ppc_init();
@@ -330,7 +329,6 @@ static void __exit acpi_processor_driver_exit(void)
 	acpi_processor_ppc_exit();
 	acpi_thermal_cpufreq_exit();
 	unregister_hotcpu_notifier(&acpi_cpu_notifier);
-	acpi_processor_syscore_exit();
 	driver_unregister(&acpi_processor_driver);
 }
 

drivers/acpi/processor_idle.c

@@ -23,6 +23,7 @@
  *
  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  */
+#define pr_fmt(fmt) "ACPI: " fmt
 
 #include <linux/module.h>
 #include <linux/acpi.h>
@@ -30,7 +31,6 @@
 #include <linux/sched.h>       /* need_resched() */
 #include <linux/tick.h>
 #include <linux/cpuidle.h>
-#include <linux/syscore_ops.h>
 #include <acpi/processor.h>
 
 /*
@@ -43,8 +43,6 @@
 #include <asm/apic.h>
 #endif
 
-#define PREFIX "ACPI: "
-
 #define ACPI_PROCESSOR_CLASS            "processor"
 #define _COMPONENT              ACPI_PROCESSOR_COMPONENT
 ACPI_MODULE_NAME("processor_idle");
@@ -81,7 +79,7 @@ static int set_max_cstate(const struct dmi_system_id *id)
 	if (max_cstate > ACPI_PROCESSOR_MAX_POWER)
 		return 0;
 
-	printk(KERN_NOTICE PREFIX "%s detected - limiting to C%ld max_cstate."
+	pr_notice("%s detected - limiting to C%ld max_cstate."
 		  " Override with \"processor.max_cstate=%d\"\n", id->ident,
 		  (long)id->driver_data, ACPI_PROCESSOR_MAX_POWER + 1);
 
@@ -194,42 +192,6 @@ static void lapic_timer_state_broadcast(struct acpi_processor *pr,
 
 #endif
 
-#ifdef CONFIG_PM_SLEEP
-static u32 saved_bm_rld;
-
-static int acpi_processor_suspend(void)
-{
-	acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_RLD, &saved_bm_rld);
-	return 0;
-}
-
-static void acpi_processor_resume(void)
-{
-	u32 resumed_bm_rld = 0;
-
-	acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_RLD, &resumed_bm_rld);
-	if (resumed_bm_rld == saved_bm_rld)
-		return;
-
-	acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, saved_bm_rld);
-}
-
-static struct syscore_ops acpi_processor_syscore_ops = {
-	.suspend = acpi_processor_suspend,
-	.resume = acpi_processor_resume,
-};
-
-void acpi_processor_syscore_init(void)
-{
-	register_syscore_ops(&acpi_processor_syscore_ops);
-}
-
-void acpi_processor_syscore_exit(void)
-{
-	unregister_syscore_ops(&acpi_processor_syscore_ops);
-}
-#endif /* CONFIG_PM_SLEEP */
-
 #if defined(CONFIG_X86)
 static void tsc_check_state(int state)
 {
@@ -351,7 +313,7 @@ static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
 
 	/* There must be at least 2 elements */
 	if (!cst || (cst->type != ACPI_TYPE_PACKAGE) || cst->package.count < 2) {
-		printk(KERN_ERR PREFIX "not enough elements in _CST\n");
+		pr_err("not enough elements in _CST\n");
 		ret = -EFAULT;
 		goto end;
 	}
@@ -360,7 +322,7 @@ static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
 
 	/* Validate number of power states. */
 	if (count < 1 || count != cst->package.count - 1) {
-		printk(KERN_ERR PREFIX "count given by _CST is not valid\n");
+		pr_err("count given by _CST is not valid\n");
 		ret = -EFAULT;
 		goto end;
 	}
@@ -469,11 +431,9 @@ static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
 		 * (From 1 through ACPI_PROCESSOR_MAX_POWER - 1)
 		 */
 		if (current_count >= (ACPI_PROCESSOR_MAX_POWER - 1)) {
-			printk(KERN_WARNING
-			       "Limiting number of power states to max (%d)\n",
+			pr_warn("Limiting number of power states to max (%d)\n",
 				ACPI_PROCESSOR_MAX_POWER);
-			printk(KERN_WARNING
-			       "Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
+			pr_warn("Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
 			break;
 		}
 	}
@@ -1097,7 +1057,7 @@ int acpi_processor_power_init(struct acpi_processor *pr)
 			retval = cpuidle_register_driver(&acpi_idle_driver);
 			if (retval)
 				return retval;
-			printk(KERN_DEBUG "ACPI: %s registered with cpuidle\n",
+			pr_debug("%s registered with cpuidle\n",
 				 acpi_idle_driver.name);
 		}
 

drivers/acpi/sleep.c

@@ -19,6 +19,7 @@
 #include <linux/reboot.h>
 #include <linux/acpi.h>
 #include <linux/module.h>
+#include <linux/syscore_ops.h>
 #include <asm/io.h>
 #include <trace/events/power.h>
 
@@ -677,6 +678,39 @@ static void acpi_sleep_suspend_setup(void)
 static inline void acpi_sleep_suspend_setup(void) {}
 #endif /* !CONFIG_SUSPEND */
 
+#ifdef CONFIG_PM_SLEEP
+static u32 saved_bm_rld;
+
+static int  acpi_save_bm_rld(void)
+{
+	acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_RLD, &saved_bm_rld);
+	return 0;
+}
+
+static void  acpi_restore_bm_rld(void)
+{
+	u32 resumed_bm_rld = 0;
+
+	acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_RLD, &resumed_bm_rld);
+	if (resumed_bm_rld == saved_bm_rld)
+		return;
+
+	acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, saved_bm_rld);
+}
+
+static struct syscore_ops acpi_sleep_syscore_ops = {
+	.suspend = acpi_save_bm_rld,
+	.resume = acpi_restore_bm_rld,
+};
+
+void acpi_sleep_syscore_init(void)
+{
+	register_syscore_ops(&acpi_sleep_syscore_ops);
+}
+#else
+static inline void acpi_sleep_syscore_init(void) {}
+#endif /* CONFIG_PM_SLEEP */
+
 #ifdef CONFIG_HIBERNATION
 static unsigned long s4_hardware_signature;
 static struct acpi_table_facs *facs;
@@ -839,6 +873,7 @@ int __init acpi_sleep_init(void)
 
 	sleep_states[ACPI_STATE_S0] = 1;
 
+	acpi_sleep_syscore_init();
 	acpi_sleep_suspend_setup();
 	acpi_sleep_hibernate_setup();
 

drivers/mailbox/pcc.c

@@ -63,6 +63,7 @@
 #include <linux/platform_device.h>
 #include <linux/mailbox_controller.h>
 #include <linux/mailbox_client.h>
+#include <linux/io-64-nonatomic-lo-hi.h>
 
 #include "mailbox.h"
 
@@ -70,6 +71,9 @@
 
 static struct mbox_chan *pcc_mbox_channels;
 
+/* Array of cached virtual address for doorbell registers */
+static void __iomem **pcc_doorbell_vaddr;
+
 static struct mbox_controller pcc_mbox_ctrl = {};
 /**
  * get_pcc_channel - Given a PCC subspace idx, get
@@ -160,6 +164,66 @@ void pcc_mbox_free_channel(struct mbox_chan *chan)
 }
 EXPORT_SYMBOL_GPL(pcc_mbox_free_channel);
 
+/*
+ * PCC can be used with perf critical drivers such as CPPC
+ * So it makes sense to locally cache the virtual address and
+ * use it to read/write to PCC registers such as doorbell register
+ *
+ * The below read_register and write_registers are used to read and
+ * write from perf critical registers such as PCC doorbell register
+ */
+static int read_register(void __iomem *vaddr, u64 *val, unsigned int bit_width)
+{
+	int ret_val = 0;
+
+	switch (bit_width) {
+	case 8:
+		*val = readb(vaddr);
+		break;
+	case 16:
+		*val = readw(vaddr);
+		break;
+	case 32:
+		*val = readl(vaddr);
+		break;
+	case 64:
+		*val = readq(vaddr);
+		break;
+	default:
+		pr_debug("Error: Cannot read register of %u bit width",
+			bit_width);
+		ret_val = -EFAULT;
+		break;
+	}
+	return ret_val;
+}
+
+static int write_register(void __iomem *vaddr, u64 val, unsigned int bit_width)
+{
+	int ret_val = 0;
+
+	switch (bit_width) {
+	case 8:
+		writeb(val, vaddr);
+		break;
+	case 16:
+		writew(val, vaddr);
+		break;
+	case 32:
+		writel(val, vaddr);
+		break;
+	case 64:
+		writeq(val, vaddr);
+		break;
+	default:
+		pr_debug("Error: Cannot write register of %u bit width",
+			bit_width);
+		ret_val = -EFAULT;
+		break;
+	}
+	return ret_val;
+}
+
 /**
  * pcc_send_data - Called from Mailbox Controller code. Used
  *		here only to ring the channel doorbell. The PCC client
@@ -175,21 +239,39 @@ EXPORT_SYMBOL_GPL(pcc_mbox_free_channel);
 static int pcc_send_data(struct mbox_chan *chan, void *data)
 {
 	struct acpi_pcct_hw_reduced *pcct_ss = chan->con_priv;
-	struct acpi_generic_address doorbell;
+	struct acpi_generic_address *doorbell;
 	u64 doorbell_preserve;
 	u64 doorbell_val;
 	u64 doorbell_write;
+	u32 id = chan - pcc_mbox_channels;
+	int ret = 0;
 
-	doorbell = pcct_ss->doorbell_register;
+	if (id >= pcc_mbox_ctrl.num_chans) {
+		pr_debug("pcc_send_data: Invalid mbox_chan passed\n");
+		return -ENOENT;
+	}
+
+	doorbell = &pcct_ss->doorbell_register;
 	doorbell_preserve = pcct_ss->preserve_mask;
 	doorbell_write = pcct_ss->write_mask;
 
 	/* Sync notification from OS to Platform. */
-	acpi_read(&doorbell_val, &doorbell);
-	acpi_write((doorbell_val & doorbell_preserve) | doorbell_write,
-			&doorbell);
-
-	return 0;
+	if (pcc_doorbell_vaddr[id]) {
+		ret = read_register(pcc_doorbell_vaddr[id], &doorbell_val,
+			doorbell->bit_width);
+		if (ret)
+			return ret;
+		ret = write_register(pcc_doorbell_vaddr[id],
+			(doorbell_val & doorbell_preserve) | doorbell_write,
+			doorbell->bit_width);
+	} else {
+		ret = acpi_read(&doorbell_val, doorbell);
+		if (ret)
+			return ret;
+		ret = acpi_write((doorbell_val & doorbell_preserve) | doorbell_write,
+			doorbell);
+	}
+	return ret;
 }
 
 static const struct mbox_chan_ops pcc_chan_ops = {
@@ -265,14 +347,29 @@ static int __init acpi_pcc_probe(void)
 		return -ENOMEM;
 	}
 
+	pcc_doorbell_vaddr = kcalloc(count, sizeof(void *), GFP_KERNEL);
+	if (!pcc_doorbell_vaddr) {
+		kfree(pcc_mbox_channels);
+		return -ENOMEM;
+	}
+
 	/* Point to the first PCC subspace entry */
 	pcct_entry = (struct acpi_subtable_header *) (
 		(unsigned long) pcct_tbl + sizeof(struct acpi_table_pcct));
 
 	for (i = 0; i < count; i++) {
+		struct acpi_generic_address *db_reg;
+		struct acpi_pcct_hw_reduced *pcct_ss;
 		pcc_mbox_channels[i].con_priv = pcct_entry;
 		pcct_entry = (struct acpi_subtable_header *)
 			((unsigned long) pcct_entry + pcct_entry->length);
+
+		/* If doorbell is in system memory cache the virt address */
+		pcct_ss = (struct acpi_pcct_hw_reduced *)pcct_entry;
+		db_reg = &pcct_ss->doorbell_register;
+		if (db_reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY)
+			pcc_doorbell_vaddr[i] = acpi_os_ioremap(db_reg->address,
+							db_reg->bit_width/8);
 	}
 
 	pcc_mbox_ctrl.num_chans = count;

include/acpi/processor.h

@@ -9,6 +9,7 @@
 #define ACPI_PROCESSOR_CLASS		"processor"
 #define ACPI_PROCESSOR_DEVICE_NAME	"Processor"
 #define ACPI_PROCESSOR_DEVICE_HID	"ACPI0007"
+#define ACPI_PROCESSOR_CONTAINER_HID	"ACPI0010"
 
 #define ACPI_PROCESSOR_BUSY_METRIC	10
 
@@ -394,14 +395,6 @@ static inline int acpi_processor_hotplug(struct acpi_processor *pr)
 }
 #endif /* CONFIG_ACPI_PROCESSOR_IDLE */
 
-#if defined(CONFIG_PM_SLEEP) & defined(CONFIG_ACPI_PROCESSOR_IDLE)
-void acpi_processor_syscore_init(void);
-void acpi_processor_syscore_exit(void);
-#else
-static inline void acpi_processor_syscore_init(void) {}
-static inline void acpi_processor_syscore_exit(void) {}
-#endif
-
 /* in processor_thermal.c */
 int acpi_processor_get_limit_info(struct acpi_processor *pr);
 extern const struct thermal_cooling_device_ops processor_cooling_ops;