| // 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"); |
| 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); |