Merge tag 'acpi-pcc-updates-6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux

Merge ACPI PCC changes for v6.7 from Sudeep Holla:

"ACPI: PCC: Mailbox and generic updates for v6.7

 Main updates include:
 1. Addition of support for Type 4 PCC subspace that enables platform
    notification handling (Huisong Li).
 2. Support for the shared interrupt amongst multiple PCC subspaces/
    channels (Huisong Li).
 3. Consolidation of PCC shared memory region command and status
    bitfields definitions that were duplicated and scattered across
    multiple PCC client drivers (Sudeep Holla)."

* tag 'acpi-pcc-updates-6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux:
  soc: kunpeng_hccs: Migrate to use generic PCC shmem related macros
  hwmon: (xgene) Migrate to use generic PCC shmem related macros
  i2c: xgene-slimpro: Migrate to use generic PCC shmem related macros
  ACPI: PCC: Add PCC shared memory region command and status bitfields
  mailbox: pcc: Support shared interrupt for multiple subspaces
  mailbox: pcc: Add support for platform notification handling

Author: rafaeljw

drivers/hwmon/xgene-hwmon.c

@@ -57,12 +57,6 @@
 	(MSG_TYPE_SET(MSG_TYPE_PWRMGMT) | \
 	MSG_SUBTYPE_SET(hndl) | TPC_CMD_SET(cmd) | type)
 
-/* PCC defines */
-#define PCC_SIGNATURE_MASK		0x50424300
-#define PCCC_GENERATE_DB_INT		BIT(15)
-#define PCCS_CMD_COMPLETE		BIT(0)
-#define PCCS_SCI_DOORBEL		BIT(1)
-#define PCCS_PLATFORM_NOTIFICATION	BIT(3)
 /*
  * Arbitrary retries in case the remote processor is slow to respond
  * to PCC commands
@@ -142,15 +136,15 @@ static int xgene_hwmon_pcc_rd(struct xgene_hwmon_dev *ctx, u32 *msg)
 
 	/* Write signature for subspace */
 	WRITE_ONCE(generic_comm_base->signature,
-		   cpu_to_le32(PCC_SIGNATURE_MASK | ctx->mbox_idx));
+		   cpu_to_le32(PCC_SIGNATURE | ctx->mbox_idx));
 
 	/* Write to the shared command region */
 	WRITE_ONCE(generic_comm_base->command,
-		   cpu_to_le16(MSG_TYPE(msg[0]) | PCCC_GENERATE_DB_INT));
+		   cpu_to_le16(MSG_TYPE(msg[0]) | PCC_CMD_GENERATE_DB_INTR));
 
 	/* Flip CMD COMPLETE bit */
 	val = le16_to_cpu(READ_ONCE(generic_comm_base->status));
-	val &= ~PCCS_CMD_COMPLETE;
+	val &= ~PCC_STATUS_CMD_COMPLETE;
 	WRITE_ONCE(generic_comm_base->status, cpu_to_le16(val));
 
 	/* Copy the message to the PCC comm space */
@@ -544,7 +538,7 @@ static void xgene_hwmon_pcc_rx_cb(struct mbox_client *cl, void *msg)
 	msg = generic_comm_base + 1;
 	/* Check if platform sends interrupt */
 	if (!xgene_word_tst_and_clr(&generic_comm_base->status,
-				    PCCS_SCI_DOORBEL))
+				    PCC_STATUS_SCI_DOORBELL))
 		return;
 
 	/*
@@ -566,7 +560,7 @@ static void xgene_hwmon_pcc_rx_cb(struct mbox_client *cl, void *msg)
 	      TPC_CMD(((u32 *)msg)[0]) == TPC_ALARM))) {
 		/* Check if platform completes command */
 		if (xgene_word_tst_and_clr(&generic_comm_base->status,
-					   PCCS_CMD_COMPLETE)) {
+					   PCC_STATUS_CMD_COMPLETE)) {
 			ctx->sync_msg.msg = ((u32 *)msg)[0];
 			ctx->sync_msg.param1 = ((u32 *)msg)[1];
 			ctx->sync_msg.param2 = ((u32 *)msg)[2];

drivers/i2c/busses/i2c-xgene-slimpro.c

@@ -91,14 +91,6 @@
 
 #define SLIMPRO_IIC_MSG_DWORD_COUNT			3
 
-/* PCC related defines */
-#define PCC_SIGNATURE			0x50424300
-#define PCC_STS_CMD_COMPLETE		BIT(0)
-#define PCC_STS_SCI_DOORBELL		BIT(1)
-#define PCC_STS_ERR			BIT(2)
-#define PCC_STS_PLAT_NOTIFY		BIT(3)
-#define PCC_CMD_GENERATE_DB_INT		BIT(15)
-
 struct slimpro_i2c_dev {
 	struct i2c_adapter adapter;
 	struct device *dev;
@@ -160,11 +152,11 @@ static void slimpro_i2c_pcc_rx_cb(struct mbox_client *cl, void *msg)
 
 	/* Check if platform sends interrupt */
 	if (!xgene_word_tst_and_clr(&generic_comm_base->status,
-				    PCC_STS_SCI_DOORBELL))
+				    PCC_STATUS_SCI_DOORBELL))
 		return;
 
 	if (xgene_word_tst_and_clr(&generic_comm_base->status,
-				   PCC_STS_CMD_COMPLETE)) {
+				   PCC_STATUS_CMD_COMPLETE)) {
 		msg = generic_comm_base + 1;
 
 		/* Response message msg[1] contains the return value. */
@@ -186,10 +178,10 @@ static void slimpro_i2c_pcc_tx_prepare(struct slimpro_i2c_dev *ctx, u32 *msg)
 		   cpu_to_le32(PCC_SIGNATURE | ctx->mbox_idx));
 
 	WRITE_ONCE(generic_comm_base->command,
-		   cpu_to_le16(SLIMPRO_MSG_TYPE(msg[0]) | PCC_CMD_GENERATE_DB_INT));
+		   cpu_to_le16(SLIMPRO_MSG_TYPE(msg[0]) | PCC_CMD_GENERATE_DB_INTR));
 
 	status = le16_to_cpu(READ_ONCE(generic_comm_base->status));
-	status &= ~PCC_STS_CMD_COMPLETE;
+	status &= ~PCC_STATUS_CMD_COMPLETE;
 	WRITE_ONCE(generic_comm_base->status, cpu_to_le16(status));
 
 	/* Copy the message to the PCC comm space */

drivers/mailbox/pcc.c

@@ -91,6 +91,14 @@ struct pcc_chan_reg {
  * @cmd_update: PCC register bundle for the command complete update register
  * @error: PCC register bundle for the error status register
  * @plat_irq: platform interrupt
+ * @type: PCC subspace type
+ * @plat_irq_flags: platform interrupt flags
+ * @chan_in_use: this flag is used just to check if the interrupt needs
+ *		handling when it is shared. Since only one transfer can occur
+ *		at a time and mailbox takes care of locking, this flag can be
+ *		accessed without a lock. Note: the type only support the
+ *		communication from OSPM to Platform, like type3, use it, and
+ *		other types completely ignore it.
  */
 struct pcc_chan_info {
 	struct pcc_mbox_chan chan;
@@ -100,12 +108,17 @@ struct pcc_chan_info {
 	struct pcc_chan_reg cmd_update;
 	struct pcc_chan_reg error;
 	int plat_irq;
+	u8 type;
+	unsigned int plat_irq_flags;
+	bool chan_in_use;
 };
 
 #define to_pcc_chan_info(c) container_of(c, struct pcc_chan_info, chan)
 static struct pcc_chan_info *chan_info;
 static int pcc_chan_count;
 
+static int pcc_send_data(struct mbox_chan *chan, void *data);
+
 /*
  * PCC can be used with perf critical drivers such as CPPC
  * So it makes sense to locally cache the virtual address and
@@ -221,6 +234,41 @@ static int pcc_map_interrupt(u32 interrupt, u32 flags)
 	return acpi_register_gsi(NULL, interrupt, trigger, polarity);
 }
 
+static bool pcc_chan_plat_irq_can_be_shared(struct pcc_chan_info *pchan)
+{
+	return (pchan->plat_irq_flags & ACPI_PCCT_INTERRUPT_MODE) ==
+		ACPI_LEVEL_SENSITIVE;
+}
+
+static bool pcc_mbox_cmd_complete_check(struct pcc_chan_info *pchan)
+{
+	u64 val;
+	int ret;
+
+	ret = pcc_chan_reg_read(&pchan->cmd_complete, &val);
+	if (ret)
+		return false;
+
+	if (!pchan->cmd_complete.gas)
+		return true;
+
+	/*
+	 * Judge if the channel respond the interrupt based on the value of
+	 * command complete.
+	 */
+	val &= pchan->cmd_complete.status_mask;
+
+	/*
+	 * If this is PCC slave subspace channel, and the command complete
+	 * bit 0 indicates that Platform is sending a notification and OSPM
+	 * needs to respond this interrupt to process this command.
+	 */
+	if (pchan->type == ACPI_PCCT_TYPE_EXT_PCC_SLAVE_SUBSPACE)
+		return !val;
+
+	return !!val;
+}
+
 /**
  * pcc_mbox_irq - PCC mailbox interrupt handler
  * @irq:	interrupt number
@@ -236,16 +284,12 @@ static irqreturn_t pcc_mbox_irq(int irq, void *p)
 	int ret;
 
 	pchan = chan->con_priv;
-
-	ret = pcc_chan_reg_read(&pchan->cmd_complete, &val);
-	if (ret)
+	if (pchan->type == ACPI_PCCT_TYPE_EXT_PCC_MASTER_SUBSPACE &&
+	    !pchan->chan_in_use)
 		return IRQ_NONE;
 
-	if (val) { /* Ensure GAS exists and value is non-zero */
-		val &= pchan->cmd_complete.status_mask;
-		if (!val)
-			return IRQ_NONE;
-	}
+	if (!pcc_mbox_cmd_complete_check(pchan))
+		return IRQ_NONE;
 
 	ret = pcc_chan_reg_read(&pchan->error, &val);
 	if (ret)
@@ -262,6 +306,16 @@ static irqreturn_t pcc_mbox_irq(int irq, void *p)
 
 	mbox_chan_received_data(chan, NULL);
 
+	/*
+	 * The PCC slave subspace channel needs to set the command complete bit
+	 * and ring doorbell after processing message.
+	 *
+	 * The PCC master subspace channel clears chan_in_use to free channel.
+	 */
+	if (pchan->type == ACPI_PCCT_TYPE_EXT_PCC_SLAVE_SUBSPACE)
+		pcc_send_data(chan, NULL);
+	pchan->chan_in_use = false;
+
 	return IRQ_HANDLED;
 }
 
@@ -340,7 +394,11 @@ static int pcc_send_data(struct mbox_chan *chan, void *data)
 	if (ret)
 		return ret;
 
-	return pcc_chan_reg_read_modify_write(&pchan->db);
+	ret = pcc_chan_reg_read_modify_write(&pchan->db);
+	if (!ret && pchan->plat_irq > 0)
+		pchan->chan_in_use = true;
+
+	return ret;
 }
 
 /**
@@ -353,11 +411,14 @@ static int pcc_send_data(struct mbox_chan *chan, void *data)
 static int pcc_startup(struct mbox_chan *chan)
 {
 	struct pcc_chan_info *pchan = chan->con_priv;
+	unsigned long irqflags;
 	int rc;
 
 	if (pchan->plat_irq > 0) {
-		rc = devm_request_irq(chan->mbox->dev, pchan->plat_irq, pcc_mbox_irq, 0,
-				      MBOX_IRQ_NAME, chan);
+		irqflags = pcc_chan_plat_irq_can_be_shared(pchan) ?
+						IRQF_SHARED | IRQF_ONESHOT : 0;
+		rc = devm_request_irq(chan->mbox->dev, pchan->plat_irq, pcc_mbox_irq,
+				      irqflags, MBOX_IRQ_NAME, chan);
 		if (unlikely(rc)) {
 			dev_err(chan->mbox->dev, "failed to register PCC interrupt %d\n",
 				pchan->plat_irq);
@@ -463,6 +524,7 @@ static int pcc_parse_subspace_irq(struct pcc_chan_info *pchan,
 		       pcct_ss->platform_interrupt);
 		return -EINVAL;
 	}
+	pchan->plat_irq_flags = pcct_ss->flags;
 
 	if (pcct_ss->header.type == ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE_TYPE2) {
 		struct acpi_pcct_hw_reduced_type2 *pcct2_ss = (void *)pcct_ss;
@@ -484,6 +546,12 @@ static int pcc_parse_subspace_irq(struct pcc_chan_info *pchan,
 					"PLAT IRQ ACK");
 	}
 
+	if (pcc_chan_plat_irq_can_be_shared(pchan) &&
+	    !pchan->plat_irq_ack.gas) {
+		pr_err("PCC subspace has level IRQ with no ACK register\n");
+		return -EINVAL;
+	}
+
 	return ret;
 }
 
@@ -698,6 +766,7 @@ static int pcc_mbox_probe(struct platform_device *pdev)
 
 		pcc_parse_subspace_shmem(pchan, pcct_entry);
 
+		pchan->type = pcct_entry->type;
 		pcct_entry = (struct acpi_subtable_header *)
 			((unsigned long) pcct_entry + pcct_entry->length);
 	}

drivers/soc/hisilicon/kunpeng_hccs.c

@@ -31,10 +31,6 @@
 
 #include "kunpeng_hccs.h"
 
-/* PCC defines */
-#define HCCS_PCC_SIGNATURE_MASK		0x50434300
-#define HCCS_PCC_STATUS_CMD_COMPLETE	BIT(0)
-
 /*
  * Arbitrary retries in case the remote processor is slow to respond
  * to PCC commands
@@ -187,7 +183,7 @@ static int hccs_check_chan_cmd_complete(struct hccs_dev *hdev)
 	 * deadline_us(timeout_us) until PCC command complete bit is set(cond)
 	 */
 	ret = readw_poll_timeout(&comm_base->status, status,
-				 status & HCCS_PCC_STATUS_CMD_COMPLETE,
+				 status & PCC_STATUS_CMD_COMPLETE,
 				 HCCS_POLL_STATUS_TIME_INTERVAL_US,
 				 cl_info->deadline_us);
 	if (unlikely(ret))
@@ -208,7 +204,7 @@ static int hccs_pcc_cmd_send(struct hccs_dev *hdev, u8 cmd,
 	int ret;
 
 	/* Write signature for this subspace */
-	tmp.signature = HCCS_PCC_SIGNATURE_MASK | hdev->chan_id;
+	tmp.signature = PCC_SIGNATURE | hdev->chan_id;
 	/* Write to the shared command region */
 	tmp.command = cmd;
 	/* Clear cmd complete bit */

include/acpi/pcc.h

@@ -18,7 +18,20 @@ struct pcc_mbox_chan {
 	u16 min_turnaround_time;
 };
 
+/* Generic Communications Channel Shared Memory Region */
+#define PCC_SIGNATURE			0x50434300
+/* Generic Communications Channel Command Field */
+#define PCC_CMD_GENERATE_DB_INTR	BIT(15)
+/* Generic Communications Channel Status Field */
+#define PCC_STATUS_CMD_COMPLETE		BIT(0)
+#define PCC_STATUS_SCI_DOORBELL		BIT(1)
+#define PCC_STATUS_ERROR		BIT(2)
+#define PCC_STATUS_PLATFORM_NOTIFY	BIT(3)
+/* Initiator Responder Communications Channel Flags */
+#define PCC_CMD_COMPLETION_NOTIFY	BIT(0)
+
 #define MAX_PCC_SUBSPACES	256
+
 #ifdef CONFIG_PCC
 extern struct pcc_mbox_chan *
 pcc_mbox_request_channel(struct mbox_client *cl, int subspace_id);