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-rw-r--r--drivers/mailbox/pcc.c758
1 files changed, 758 insertions, 0 deletions
diff --git a/drivers/mailbox/pcc.c b/drivers/mailbox/pcc.c
new file mode 100644
index 000000000..105d46c98
--- /dev/null
+++ b/drivers/mailbox/pcc.c
@@ -0,0 +1,758 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2014 Linaro Ltd.
+ * Author: Ashwin Chaugule <ashwin.chaugule@linaro.org>
+ *
+ * PCC (Platform Communication Channel) is defined in the ACPI 5.0+
+ * specification. It is a mailbox like mechanism to allow clients
+ * such as CPPC (Collaborative Processor Performance Control), RAS
+ * (Reliability, Availability and Serviceability) and MPST (Memory
+ * Node Power State Table) to talk to the platform (e.g. BMC) through
+ * shared memory regions as defined in the PCC table entries. The PCC
+ * specification supports a Doorbell mechanism for the PCC clients
+ * to notify the platform about new data. This Doorbell information
+ * is also specified in each PCC table entry.
+ *
+ * Typical high level flow of operation is:
+ *
+ * PCC Reads:
+ * * Client tries to acquire a channel lock.
+ * * After it is acquired it writes READ cmd in communication region cmd
+ * address.
+ * * Client issues mbox_send_message() which rings the PCC doorbell
+ * for its PCC channel.
+ * * If command completes, then client has control over channel and
+ * it can proceed with its reads.
+ * * Client releases lock.
+ *
+ * PCC Writes:
+ * * Client tries to acquire channel lock.
+ * * Client writes to its communication region after it acquires a
+ * channel lock.
+ * * Client writes WRITE cmd in communication region cmd address.
+ * * Client issues mbox_send_message() which rings the PCC doorbell
+ * for its PCC channel.
+ * * If command completes, then writes have succeeded and it can release
+ * the channel lock.
+ *
+ * There is a Nominal latency defined for each channel which indicates
+ * how long to wait until a command completes. If command is not complete
+ * the client needs to retry or assume failure.
+ *
+ * For more details about PCC, please see the ACPI specification from
+ * http://www.uefi.org/ACPIv5.1 Section 14.
+ *
+ * This file implements PCC as a Mailbox controller and allows for PCC
+ * clients to be implemented as its Mailbox Client Channels.
+ */
+
+#include <linux/acpi.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/list.h>
+#include <linux/log2.h>
+#include <linux/platform_device.h>
+#include <linux/mailbox_controller.h>
+#include <linux/mailbox_client.h>
+#include <linux/io-64-nonatomic-lo-hi.h>
+#include <acpi/pcc.h>
+
+#include "mailbox.h"
+
+#define MBOX_IRQ_NAME "pcc-mbox"
+
+/**
+ * struct pcc_chan_reg - PCC register bundle
+ *
+ * @vaddr: cached virtual address for this register
+ * @gas: pointer to the generic address structure for this register
+ * @preserve_mask: bitmask to preserve when writing to this register
+ * @set_mask: bitmask to set when writing to this register
+ * @status_mask: bitmask to determine and/or update the status for this register
+ */
+struct pcc_chan_reg {
+ void __iomem *vaddr;
+ struct acpi_generic_address *gas;
+ u64 preserve_mask;
+ u64 set_mask;
+ u64 status_mask;
+};
+
+/**
+ * struct pcc_chan_info - PCC channel specific information
+ *
+ * @chan: PCC channel information with Shared Memory Region info
+ * @db: PCC register bundle for the doorbell register
+ * @plat_irq_ack: PCC register bundle for the platform interrupt acknowledge
+ * register
+ * @cmd_complete: PCC register bundle for the command complete check register
+ * @cmd_update: PCC register bundle for the command complete update register
+ * @error: PCC register bundle for the error status register
+ * @plat_irq: platform interrupt
+ */
+struct pcc_chan_info {
+ struct pcc_mbox_chan chan;
+ struct pcc_chan_reg db;
+ struct pcc_chan_reg plat_irq_ack;
+ struct pcc_chan_reg cmd_complete;
+ struct pcc_chan_reg cmd_update;
+ struct pcc_chan_reg error;
+ int plat_irq;
+};
+
+#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;
+
+/*
+ * 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 void read_register(void __iomem *vaddr, u64 *val, unsigned int bit_width)
+{
+ 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;
+ }
+}
+
+static void write_register(void __iomem *vaddr, u64 val, unsigned int bit_width)
+{
+ 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;
+ }
+}
+
+static int pcc_chan_reg_read(struct pcc_chan_reg *reg, u64 *val)
+{
+ int ret = 0;
+
+ if (!reg->gas) {
+ *val = 0;
+ return 0;
+ }
+
+ if (reg->vaddr)
+ read_register(reg->vaddr, val, reg->gas->bit_width);
+ else
+ ret = acpi_read(val, reg->gas);
+
+ return ret;
+}
+
+static int pcc_chan_reg_write(struct pcc_chan_reg *reg, u64 val)
+{
+ int ret = 0;
+
+ if (!reg->gas)
+ return 0;
+
+ if (reg->vaddr)
+ write_register(reg->vaddr, val, reg->gas->bit_width);
+ else
+ ret = acpi_write(val, reg->gas);
+
+ return ret;
+}
+
+static int pcc_chan_reg_read_modify_write(struct pcc_chan_reg *reg)
+{
+ int ret = 0;
+ u64 val;
+
+ ret = pcc_chan_reg_read(reg, &val);
+ if (ret)
+ return ret;
+
+ val &= reg->preserve_mask;
+ val |= reg->set_mask;
+
+ return pcc_chan_reg_write(reg, val);
+}
+
+/**
+ * pcc_map_interrupt - Map a PCC subspace GSI to a linux IRQ number
+ * @interrupt: GSI number.
+ * @flags: interrupt flags
+ *
+ * Returns: a valid linux IRQ number on success
+ * 0 or -EINVAL on failure
+ */
+static int pcc_map_interrupt(u32 interrupt, u32 flags)
+{
+ int trigger, polarity;
+
+ if (!interrupt)
+ return 0;
+
+ trigger = (flags & ACPI_PCCT_INTERRUPT_MODE) ? ACPI_EDGE_SENSITIVE
+ : ACPI_LEVEL_SENSITIVE;
+
+ polarity = (flags & ACPI_PCCT_INTERRUPT_POLARITY) ? ACPI_ACTIVE_LOW
+ : ACPI_ACTIVE_HIGH;
+
+ return acpi_register_gsi(NULL, interrupt, trigger, polarity);
+}
+
+/**
+ * pcc_mbox_irq - PCC mailbox interrupt handler
+ * @irq: interrupt number
+ * @p: data/cookie passed from the caller to identify the channel
+ *
+ * Returns: IRQ_HANDLED if interrupt is handled or IRQ_NONE if not
+ */
+static irqreturn_t pcc_mbox_irq(int irq, void *p)
+{
+ struct pcc_chan_info *pchan;
+ struct mbox_chan *chan = p;
+ u64 val;
+ int ret;
+
+ pchan = chan->con_priv;
+
+ ret = pcc_chan_reg_read(&pchan->cmd_complete, &val);
+ if (ret)
+ return IRQ_NONE;
+
+ if (val) { /* Ensure GAS exists and value is non-zero */
+ val &= pchan->cmd_complete.status_mask;
+ if (!val)
+ return IRQ_NONE;
+ }
+
+ ret = pcc_chan_reg_read(&pchan->error, &val);
+ if (ret)
+ return IRQ_NONE;
+ val &= pchan->error.status_mask;
+ if (val) {
+ val &= ~pchan->error.status_mask;
+ pcc_chan_reg_write(&pchan->error, val);
+ return IRQ_NONE;
+ }
+
+ if (pcc_chan_reg_read_modify_write(&pchan->plat_irq_ack))
+ return IRQ_NONE;
+
+ mbox_chan_received_data(chan, NULL);
+
+ return IRQ_HANDLED;
+}
+
+/**
+ * pcc_mbox_request_channel - PCC clients call this function to
+ * request a pointer to their PCC subspace, from which they
+ * can get the details of communicating with the remote.
+ * @cl: Pointer to Mailbox client, so we know where to bind the
+ * Channel.
+ * @subspace_id: The PCC Subspace index as parsed in the PCC client
+ * ACPI package. This is used to lookup the array of PCC
+ * subspaces as parsed by the PCC Mailbox controller.
+ *
+ * Return: Pointer to the PCC Mailbox Channel if successful or ERR_PTR.
+ */
+struct pcc_mbox_chan *
+pcc_mbox_request_channel(struct mbox_client *cl, int subspace_id)
+{
+ struct pcc_chan_info *pchan;
+ struct mbox_chan *chan;
+ struct device *dev;
+ unsigned long flags;
+
+ if (subspace_id < 0 || subspace_id >= pcc_chan_count)
+ return ERR_PTR(-ENOENT);
+
+ pchan = chan_info + subspace_id;
+ chan = pchan->chan.mchan;
+ if (IS_ERR(chan) || chan->cl) {
+ pr_err("Channel not found for idx: %d\n", subspace_id);
+ return ERR_PTR(-EBUSY);
+ }
+ dev = chan->mbox->dev;
+
+ spin_lock_irqsave(&chan->lock, flags);
+ chan->msg_free = 0;
+ chan->msg_count = 0;
+ chan->active_req = NULL;
+ chan->cl = cl;
+ init_completion(&chan->tx_complete);
+
+ if (chan->txdone_method == TXDONE_BY_POLL && cl->knows_txdone)
+ chan->txdone_method = TXDONE_BY_ACK;
+
+ spin_unlock_irqrestore(&chan->lock, flags);
+
+ if (pchan->plat_irq > 0) {
+ int rc;
+
+ rc = devm_request_irq(dev, pchan->plat_irq, pcc_mbox_irq, 0,
+ MBOX_IRQ_NAME, chan);
+ if (unlikely(rc)) {
+ dev_err(dev, "failed to register PCC interrupt %d\n",
+ pchan->plat_irq);
+ pcc_mbox_free_channel(&pchan->chan);
+ return ERR_PTR(rc);
+ }
+ }
+
+ return &pchan->chan;
+}
+EXPORT_SYMBOL_GPL(pcc_mbox_request_channel);
+
+/**
+ * pcc_mbox_free_channel - Clients call this to free their Channel.
+ *
+ * @pchan: Pointer to the PCC mailbox channel as returned by
+ * pcc_mbox_request_channel()
+ */
+void pcc_mbox_free_channel(struct pcc_mbox_chan *pchan)
+{
+ struct pcc_chan_info *pchan_info = to_pcc_chan_info(pchan);
+ struct mbox_chan *chan = pchan->mchan;
+ unsigned long flags;
+
+ if (!chan || !chan->cl)
+ return;
+
+ if (pchan_info->plat_irq > 0)
+ devm_free_irq(chan->mbox->dev, pchan_info->plat_irq, chan);
+
+ spin_lock_irqsave(&chan->lock, flags);
+ chan->cl = NULL;
+ chan->active_req = NULL;
+ if (chan->txdone_method == TXDONE_BY_ACK)
+ chan->txdone_method = TXDONE_BY_POLL;
+
+ spin_unlock_irqrestore(&chan->lock, flags);
+}
+EXPORT_SYMBOL_GPL(pcc_mbox_free_channel);
+
+/**
+ * pcc_send_data - Called from Mailbox Controller code. Used
+ * here only to ring the channel doorbell. The PCC client
+ * specific read/write is done in the client driver in
+ * order to maintain atomicity over PCC channel once
+ * OS has control over it. See above for flow of operations.
+ * @chan: Pointer to Mailbox channel over which to send data.
+ * @data: Client specific data written over channel. Used here
+ * only for debug after PCC transaction completes.
+ *
+ * Return: Err if something failed else 0 for success.
+ */
+static int pcc_send_data(struct mbox_chan *chan, void *data)
+{
+ int ret;
+ struct pcc_chan_info *pchan = chan->con_priv;
+
+ ret = pcc_chan_reg_read_modify_write(&pchan->cmd_update);
+ if (ret)
+ return ret;
+
+ return pcc_chan_reg_read_modify_write(&pchan->db);
+}
+
+static const struct mbox_chan_ops pcc_chan_ops = {
+ .send_data = pcc_send_data,
+};
+
+/**
+ * parse_pcc_subspace - Count PCC subspaces defined
+ * @header: Pointer to the ACPI subtable header under the PCCT.
+ * @end: End of subtable entry.
+ *
+ * Return: If we find a PCC subspace entry of a valid type, return 0.
+ * Otherwise, return -EINVAL.
+ *
+ * This gets called for each entry in the PCC table.
+ */
+static int parse_pcc_subspace(union acpi_subtable_headers *header,
+ const unsigned long end)
+{
+ struct acpi_pcct_subspace *ss = (struct acpi_pcct_subspace *) header;
+
+ if (ss->header.type < ACPI_PCCT_TYPE_RESERVED)
+ return 0;
+
+ return -EINVAL;
+}
+
+static int
+pcc_chan_reg_init(struct pcc_chan_reg *reg, struct acpi_generic_address *gas,
+ u64 preserve_mask, u64 set_mask, u64 status_mask, char *name)
+{
+ if (gas->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) {
+ if (!(gas->bit_width >= 8 && gas->bit_width <= 64 &&
+ is_power_of_2(gas->bit_width))) {
+ pr_err("Error: Cannot access register of %u bit width",
+ gas->bit_width);
+ return -EFAULT;
+ }
+
+ reg->vaddr = acpi_os_ioremap(gas->address, gas->bit_width / 8);
+ if (!reg->vaddr) {
+ pr_err("Failed to ioremap PCC %s register\n", name);
+ return -ENOMEM;
+ }
+ }
+ reg->gas = gas;
+ reg->preserve_mask = preserve_mask;
+ reg->set_mask = set_mask;
+ reg->status_mask = status_mask;
+ return 0;
+}
+
+/**
+ * pcc_parse_subspace_irq - Parse the PCC IRQ and PCC ACK register
+ *
+ * @pchan: Pointer to the PCC channel info structure.
+ * @pcct_entry: Pointer to the ACPI subtable header.
+ *
+ * Return: 0 for Success, else errno.
+ *
+ * There should be one entry per PCC channel. This gets called for each
+ * entry in the PCC table. This uses PCCY Type1 structure for all applicable
+ * types(Type 1-4) to fetch irq
+ */
+static int pcc_parse_subspace_irq(struct pcc_chan_info *pchan,
+ struct acpi_subtable_header *pcct_entry)
+{
+ int ret = 0;
+ struct acpi_pcct_hw_reduced *pcct_ss;
+
+ if (pcct_entry->type < ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE ||
+ pcct_entry->type > ACPI_PCCT_TYPE_EXT_PCC_SLAVE_SUBSPACE)
+ return 0;
+
+ pcct_ss = (struct acpi_pcct_hw_reduced *)pcct_entry;
+ pchan->plat_irq = pcc_map_interrupt(pcct_ss->platform_interrupt,
+ (u32)pcct_ss->flags);
+ if (pchan->plat_irq <= 0) {
+ pr_err("PCC GSI %d not registered\n",
+ pcct_ss->platform_interrupt);
+ return -EINVAL;
+ }
+
+ if (pcct_ss->header.type == ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE_TYPE2) {
+ struct acpi_pcct_hw_reduced_type2 *pcct2_ss = (void *)pcct_ss;
+
+ ret = pcc_chan_reg_init(&pchan->plat_irq_ack,
+ &pcct2_ss->platform_ack_register,
+ pcct2_ss->ack_preserve_mask,
+ pcct2_ss->ack_write_mask, 0,
+ "PLAT IRQ ACK");
+
+ } else if (pcct_ss->header.type == ACPI_PCCT_TYPE_EXT_PCC_MASTER_SUBSPACE ||
+ pcct_ss->header.type == ACPI_PCCT_TYPE_EXT_PCC_SLAVE_SUBSPACE) {
+ struct acpi_pcct_ext_pcc_master *pcct_ext = (void *)pcct_ss;
+
+ ret = pcc_chan_reg_init(&pchan->plat_irq_ack,
+ &pcct_ext->platform_ack_register,
+ pcct_ext->ack_preserve_mask,
+ pcct_ext->ack_set_mask, 0,
+ "PLAT IRQ ACK");
+ }
+
+ return ret;
+}
+
+/**
+ * pcc_parse_subspace_db_reg - Parse the PCC doorbell register
+ *
+ * @pchan: Pointer to the PCC channel info structure.
+ * @pcct_entry: Pointer to the ACPI subtable header.
+ *
+ * Return: 0 for Success, else errno.
+ */
+static int pcc_parse_subspace_db_reg(struct pcc_chan_info *pchan,
+ struct acpi_subtable_header *pcct_entry)
+{
+ int ret = 0;
+
+ if (pcct_entry->type <= ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE_TYPE2) {
+ struct acpi_pcct_subspace *pcct_ss;
+
+ pcct_ss = (struct acpi_pcct_subspace *)pcct_entry;
+
+ ret = pcc_chan_reg_init(&pchan->db,
+ &pcct_ss->doorbell_register,
+ pcct_ss->preserve_mask,
+ pcct_ss->write_mask, 0, "Doorbell");
+
+ } else {
+ struct acpi_pcct_ext_pcc_master *pcct_ext;
+
+ pcct_ext = (struct acpi_pcct_ext_pcc_master *)pcct_entry;
+
+ ret = pcc_chan_reg_init(&pchan->db,
+ &pcct_ext->doorbell_register,
+ pcct_ext->preserve_mask,
+ pcct_ext->write_mask, 0, "Doorbell");
+ if (ret)
+ return ret;
+
+ ret = pcc_chan_reg_init(&pchan->cmd_complete,
+ &pcct_ext->cmd_complete_register,
+ 0, 0, pcct_ext->cmd_complete_mask,
+ "Command Complete Check");
+ if (ret)
+ return ret;
+
+ ret = pcc_chan_reg_init(&pchan->cmd_update,
+ &pcct_ext->cmd_update_register,
+ pcct_ext->cmd_update_preserve_mask,
+ pcct_ext->cmd_update_set_mask, 0,
+ "Command Complete Update");
+ if (ret)
+ return ret;
+
+ ret = pcc_chan_reg_init(&pchan->error,
+ &pcct_ext->error_status_register,
+ 0, 0, pcct_ext->error_status_mask,
+ "Error Status");
+ }
+ return ret;
+}
+
+/**
+ * pcc_parse_subspace_shmem - Parse the PCC Shared Memory Region information
+ *
+ * @pchan: Pointer to the PCC channel info structure.
+ * @pcct_entry: Pointer to the ACPI subtable header.
+ *
+ */
+static void pcc_parse_subspace_shmem(struct pcc_chan_info *pchan,
+ struct acpi_subtable_header *pcct_entry)
+{
+ if (pcct_entry->type <= ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE_TYPE2) {
+ struct acpi_pcct_subspace *pcct_ss =
+ (struct acpi_pcct_subspace *)pcct_entry;
+
+ pchan->chan.shmem_base_addr = pcct_ss->base_address;
+ pchan->chan.shmem_size = pcct_ss->length;
+ pchan->chan.latency = pcct_ss->latency;
+ pchan->chan.max_access_rate = pcct_ss->max_access_rate;
+ pchan->chan.min_turnaround_time = pcct_ss->min_turnaround_time;
+ } else {
+ struct acpi_pcct_ext_pcc_master *pcct_ext =
+ (struct acpi_pcct_ext_pcc_master *)pcct_entry;
+
+ pchan->chan.shmem_base_addr = pcct_ext->base_address;
+ pchan->chan.shmem_size = pcct_ext->length;
+ pchan->chan.latency = pcct_ext->latency;
+ pchan->chan.max_access_rate = pcct_ext->max_access_rate;
+ pchan->chan.min_turnaround_time = pcct_ext->min_turnaround_time;
+ }
+}
+
+/**
+ * acpi_pcc_probe - Parse the ACPI tree for the PCCT.
+ *
+ * Return: 0 for Success, else errno.
+ */
+static int __init acpi_pcc_probe(void)
+{
+ int count, i, rc = 0;
+ acpi_status status;
+ struct acpi_table_header *pcct_tbl;
+ struct acpi_subtable_proc proc[ACPI_PCCT_TYPE_RESERVED];
+
+ status = acpi_get_table(ACPI_SIG_PCCT, 0, &pcct_tbl);
+ if (ACPI_FAILURE(status) || !pcct_tbl)
+ return -ENODEV;
+
+ /* Set up the subtable handlers */
+ for (i = ACPI_PCCT_TYPE_GENERIC_SUBSPACE;
+ i < ACPI_PCCT_TYPE_RESERVED; i++) {
+ proc[i].id = i;
+ proc[i].count = 0;
+ proc[i].handler = parse_pcc_subspace;
+ }
+
+ count = acpi_table_parse_entries_array(ACPI_SIG_PCCT,
+ sizeof(struct acpi_table_pcct), proc,
+ ACPI_PCCT_TYPE_RESERVED, MAX_PCC_SUBSPACES);
+ if (count <= 0 || count > MAX_PCC_SUBSPACES) {
+ if (count < 0)
+ pr_warn("Error parsing PCC subspaces from PCCT\n");
+ else
+ pr_warn("Invalid PCCT: %d PCC subspaces\n", count);
+
+ rc = -EINVAL;
+ } else {
+ pcc_chan_count = count;
+ }
+
+ acpi_put_table(pcct_tbl);
+
+ return rc;
+}
+
+/**
+ * pcc_mbox_probe - Called when we find a match for the
+ * PCCT platform device. This is purely used to represent
+ * the PCCT as a virtual device for registering with the
+ * generic Mailbox framework.
+ *
+ * @pdev: Pointer to platform device returned when a match
+ * is found.
+ *
+ * Return: 0 for Success, else errno.
+ */
+static int pcc_mbox_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct mbox_controller *pcc_mbox_ctrl;
+ struct mbox_chan *pcc_mbox_channels;
+ struct acpi_table_header *pcct_tbl;
+ struct acpi_subtable_header *pcct_entry;
+ struct acpi_table_pcct *acpi_pcct_tbl;
+ acpi_status status = AE_OK;
+ int i, rc, count = pcc_chan_count;
+
+ /* Search for PCCT */
+ status = acpi_get_table(ACPI_SIG_PCCT, 0, &pcct_tbl);
+
+ if (ACPI_FAILURE(status) || !pcct_tbl)
+ return -ENODEV;
+
+ pcc_mbox_channels = devm_kcalloc(dev, count, sizeof(*pcc_mbox_channels),
+ GFP_KERNEL);
+ if (!pcc_mbox_channels) {
+ rc = -ENOMEM;
+ goto err;
+ }
+
+ chan_info = devm_kcalloc(dev, count, sizeof(*chan_info), GFP_KERNEL);
+ if (!chan_info) {
+ rc = -ENOMEM;
+ goto err;
+ }
+
+ pcc_mbox_ctrl = devm_kzalloc(dev, sizeof(*pcc_mbox_ctrl), GFP_KERNEL);
+ if (!pcc_mbox_ctrl) {
+ rc = -ENOMEM;
+ goto err;
+ }
+
+ /* Point to the first PCC subspace entry */
+ pcct_entry = (struct acpi_subtable_header *) (
+ (unsigned long) pcct_tbl + sizeof(struct acpi_table_pcct));
+
+ acpi_pcct_tbl = (struct acpi_table_pcct *) pcct_tbl;
+ if (acpi_pcct_tbl->flags & ACPI_PCCT_DOORBELL)
+ pcc_mbox_ctrl->txdone_irq = true;
+
+ for (i = 0; i < count; i++) {
+ struct pcc_chan_info *pchan = chan_info + i;
+
+ pcc_mbox_channels[i].con_priv = pchan;
+ pchan->chan.mchan = &pcc_mbox_channels[i];
+
+ if (pcct_entry->type == ACPI_PCCT_TYPE_EXT_PCC_SLAVE_SUBSPACE &&
+ !pcc_mbox_ctrl->txdone_irq) {
+ pr_err("Platform Interrupt flag must be set to 1");
+ rc = -EINVAL;
+ goto err;
+ }
+
+ if (pcc_mbox_ctrl->txdone_irq) {
+ rc = pcc_parse_subspace_irq(pchan, pcct_entry);
+ if (rc < 0)
+ goto err;
+ }
+ rc = pcc_parse_subspace_db_reg(pchan, pcct_entry);
+ if (rc < 0)
+ goto err;
+
+ pcc_parse_subspace_shmem(pchan, pcct_entry);
+
+ pcct_entry = (struct acpi_subtable_header *)
+ ((unsigned long) pcct_entry + pcct_entry->length);
+ }
+
+ pcc_mbox_ctrl->num_chans = count;
+
+ pr_info("Detected %d PCC Subspaces\n", pcc_mbox_ctrl->num_chans);
+
+ pcc_mbox_ctrl->chans = pcc_mbox_channels;
+ pcc_mbox_ctrl->ops = &pcc_chan_ops;
+ pcc_mbox_ctrl->dev = dev;
+
+ pr_info("Registering PCC driver as Mailbox controller\n");
+ rc = mbox_controller_register(pcc_mbox_ctrl);
+ if (rc)
+ pr_err("Err registering PCC as Mailbox controller: %d\n", rc);
+ else
+ return 0;
+err:
+ acpi_put_table(pcct_tbl);
+ return rc;
+}
+
+static struct platform_driver pcc_mbox_driver = {
+ .probe = pcc_mbox_probe,
+ .driver = {
+ .name = "PCCT",
+ },
+};
+
+static int __init pcc_init(void)
+{
+ int ret;
+ struct platform_device *pcc_pdev;
+
+ if (acpi_disabled)
+ return -ENODEV;
+
+ /* Check if PCC support is available. */
+ ret = acpi_pcc_probe();
+
+ if (ret) {
+ pr_debug("ACPI PCC probe failed.\n");
+ return -ENODEV;
+ }
+
+ pcc_pdev = platform_create_bundle(&pcc_mbox_driver,
+ pcc_mbox_probe, NULL, 0, NULL, 0);
+
+ if (IS_ERR(pcc_pdev)) {
+ pr_debug("Err creating PCC platform bundle\n");
+ pcc_chan_count = 0;
+ return PTR_ERR(pcc_pdev);
+ }
+
+ return 0;
+}
+
+/*
+ * Make PCC init postcore so that users of this mailbox
+ * such as the ACPI Processor driver have it available
+ * at their init.
+ */
+postcore_initcall(pcc_init);
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-13 07:59:03 +0000