| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Hoan Tran | 894 | 45.71% | 3 | 15.00% |
| Ashwin Chaugule | 700 | 35.79% | 3 | 15.00% |
| Prashanth Prakash | 215 | 10.99% | 1 | 5.00% |
| Al Stone | 105 | 5.37% | 1 | 5.00% |
| David Arcari | 13 | 0.66% | 1 | 5.00% |
| Wei Yongjun | 7 | 0.36% | 1 | 5.00% |
| David E. Box | 5 | 0.26% | 1 | 5.00% |
| Kees Cook | 3 | 0.15% | 1 | 5.00% |
| Sudip Mukherjee | 3 | 0.15% | 1 | 5.00% |
| Alexey Klimov | 2 | 0.10% | 1 | 5.00% |
| Thomas Gleixner | 2 | 0.10% | 1 | 5.00% |
| Rafael J. Wysocki | 2 | 0.10% | 1 | 5.00% |
| Keith Busch | 2 | 0.10% | 1 | 5.00% |
| Andrew Bresticker | 1 | 0.05% | 1 | 5.00% |
| Lv Zheng | 1 | 0.05% | 1 | 5.00% |
| Sudeep Holla | 1 | 0.05% | 1 | 5.00% |
| Total | 1956 | 20 |
// 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 succeded 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/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" static struct mbox_chan *pcc_mbox_channels; /* Array of cached virtual address for doorbell registers */ static void __iomem **pcc_doorbell_vaddr; /* Array of cached virtual address for doorbell ack registers */ static void __iomem **pcc_doorbell_ack_vaddr; /* Array of doorbell interrupts */ static int *pcc_doorbell_irq; static struct mbox_controller pcc_mbox_ctrl = {}; /** * get_pcc_channel - Given a PCC subspace idx, get * the respective mbox_channel. * @id: PCC subspace index. * * Return: ERR_PTR(errno) if error, else pointer * to mbox channel. */ static struct mbox_chan *get_pcc_channel(int id) { if (id < 0 || id >= pcc_mbox_ctrl.num_chans) return ERR_PTR(-ENOENT); return &pcc_mbox_channels[id]; } /* * 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_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 */ static irqreturn_t pcc_mbox_irq(int irq, void *p) { struct acpi_generic_address *doorbell_ack; struct acpi_pcct_hw_reduced *pcct_ss; struct mbox_chan *chan = p; u64 doorbell_ack_preserve; u64 doorbell_ack_write; u64 doorbell_ack_val; int ret; pcct_ss = chan->con_priv; mbox_chan_received_data(chan, NULL); if (pcct_ss->header.type == ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE_TYPE2) { struct acpi_pcct_hw_reduced_type2 *pcct2_ss = chan->con_priv; u32 id = chan - pcc_mbox_channels; doorbell_ack = &pcct2_ss->platform_ack_register; doorbell_ack_preserve = pcct2_ss->ack_preserve_mask; doorbell_ack_write = pcct2_ss->ack_write_mask; ret = read_register(pcc_doorbell_ack_vaddr[id], &doorbell_ack_val, doorbell_ack->bit_width); if (ret) return IRQ_NONE; ret = write_register(pcc_doorbell_ack_vaddr[id], (doorbell_ack_val & doorbell_ack_preserve) | doorbell_ack_write, doorbell_ack->bit_width); if (ret) return IRQ_NONE; } 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 Mailbox Channel if successful or * ERR_PTR. */ struct mbox_chan *pcc_mbox_request_channel(struct mbox_client *cl, int subspace_id) { struct device *dev = pcc_mbox_ctrl.dev; struct mbox_chan *chan; unsigned long flags; /* * Each PCC Subspace is a Mailbox Channel. * The PCC Clients get their PCC Subspace ID * from their own tables and pass it here. * This returns a pointer to the PCC subspace * for the Client to operate on. */ chan = get_pcc_channel(subspace_id); if (IS_ERR(chan) || chan->cl) { dev_err(dev, "Channel not found for idx: %d\n", subspace_id); return ERR_PTR(-EBUSY); } 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 (pcc_doorbell_irq[subspace_id] > 0) { int rc; rc = devm_request_irq(dev, pcc_doorbell_irq[subspace_id], pcc_mbox_irq, 0, MBOX_IRQ_NAME, chan); if (unlikely(rc)) { dev_err(dev, "failed to register PCC interrupt %d\n", pcc_doorbell_irq[subspace_id]); pcc_mbox_free_channel(chan); chan = ERR_PTR(rc); } } return chan; } EXPORT_SYMBOL_GPL(pcc_mbox_request_channel); /** * pcc_mbox_free_channel - Clients call this to free their Channel. * * @chan: Pointer to the mailbox channel as returned by * pcc_mbox_request_channel() */ void pcc_mbox_free_channel(struct mbox_chan *chan) { u32 id = chan - pcc_mbox_channels; unsigned long flags; if (!chan || !chan->cl) return; if (id >= pcc_mbox_ctrl.num_chans) { pr_debug("pcc_mbox_free_channel: Invalid mbox_chan passed\n"); return; } if (pcc_doorbell_irq[id] > 0) devm_free_irq(chan->mbox->dev, pcc_doorbell_irq[id], 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) { struct acpi_pcct_hw_reduced *pcct_ss = chan->con_priv; struct acpi_generic_address *doorbell; u64 doorbell_preserve; u64 doorbell_val; u64 doorbell_write; u32 id = chan - pcc_mbox_channels; int ret = 0; 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. */ 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 = { .send_data = pcc_send_data, }; /** * parse_pcc_subspaces -- 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; } /** * pcc_parse_subspace_irq - Parse the PCC IRQ and PCC ACK register * There should be one entry per PCC client. * @id: PCC subspace index. * @pcct_ss: Pointer to the ACPI subtable header under the PCCT. * * Return: 0 for Success, else errno. * * This gets called for each entry in the PCC table. */ static int pcc_parse_subspace_irq(int id, struct acpi_pcct_hw_reduced *pcct_ss) { pcc_doorbell_irq[id] = pcc_map_interrupt(pcct_ss->platform_interrupt, (u32)pcct_ss->flags); if (pcc_doorbell_irq[id] <= 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; pcc_doorbell_ack_vaddr[id] = acpi_os_ioremap( pcct2_ss->platform_ack_register.address, pcct2_ss->platform_ack_register.bit_width / 8); if (!pcc_doorbell_ack_vaddr[id]) { pr_err("Failed to ioremap PCC ACK register\n"); return -ENOMEM; } } return 0; } /** * acpi_pcc_probe - Parse the ACPI tree for the PCCT. * * Return: 0 for Success, else errno. */ static int __init acpi_pcc_probe(void) { struct acpi_table_header *pcct_tbl; struct acpi_subtable_header *pcct_entry; struct acpi_table_pcct *acpi_pcct_tbl; struct acpi_subtable_proc proc[ACPI_PCCT_TYPE_RESERVED]; int count, i, rc; acpi_status status = AE_OK; /* Search for PCCT */ 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); return -EINVAL; } pcc_mbox_channels = kcalloc(count, sizeof(struct mbox_chan), GFP_KERNEL); if (!pcc_mbox_channels) { pr_err("Could not allocate space for PCC mbox channels\n"); return -ENOMEM; } pcc_doorbell_vaddr = kcalloc(count, sizeof(void *), GFP_KERNEL); if (!pcc_doorbell_vaddr) { rc = -ENOMEM; goto err_free_mbox; } pcc_doorbell_ack_vaddr = kcalloc(count, sizeof(void *), GFP_KERNEL); if (!pcc_doorbell_ack_vaddr) { rc = -ENOMEM; goto err_free_db_vaddr; } pcc_doorbell_irq = kcalloc(count, sizeof(int), GFP_KERNEL); if (!pcc_doorbell_irq) { rc = -ENOMEM; goto err_free_db_ack_vaddr; } /* 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 acpi_generic_address *db_reg; struct acpi_pcct_subspace *pcct_ss; pcc_mbox_channels[i].con_priv = pcct_entry; if (pcct_entry->type == ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE || pcct_entry->type == ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE_TYPE2) { struct acpi_pcct_hw_reduced *pcct_hrss; pcct_hrss = (struct acpi_pcct_hw_reduced *) pcct_entry; if (pcc_mbox_ctrl.txdone_irq) { rc = pcc_parse_subspace_irq(i, pcct_hrss); if (rc < 0) goto err; } } pcct_ss = (struct acpi_pcct_subspace *) pcct_entry; /* If doorbell is in system memory cache the virt address */ 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); 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); return 0; err: kfree(pcc_doorbell_irq); err_free_db_ack_vaddr: kfree(pcc_doorbell_ack_vaddr); err_free_db_vaddr: kfree(pcc_doorbell_vaddr); err_free_mbox: kfree(pcc_mbox_channels); 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) { int ret = 0; pcc_mbox_ctrl.chans = pcc_mbox_channels; pcc_mbox_ctrl.ops = &pcc_chan_ops; pcc_mbox_ctrl.dev = &pdev->dev; pr_info("Registering PCC driver as Mailbox controller\n"); ret = mbox_controller_register(&pcc_mbox_ctrl); if (ret) { pr_err("Err registering PCC as Mailbox controller: %d\n", ret); ret = -ENODEV; } return ret; } struct platform_driver pcc_mbox_driver = { .probe = pcc_mbox_probe, .driver = { .name = "PCCT", .owner = THIS_MODULE, }, }; 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);
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