From: hotran <hotran@xxxxxxx> ACPI 6.1 has a PCC HW-Reduced Communication Subspace Type 2 intended for use on HW-Reduce ACPI Platform, which requires read-modify-write sequence to acknowledge doorbell interrupt. This patch provides the implementation for the Communication Subspace Type 2. This patch depends on patch [1] which supports PCC subspace type 2 header [1] https://lkml.org/lkml/2016/5/5/14 - [PATCH v2 03/13] ACPICA: ACPI 6.1: Support for new PCCT subtable v2 * Remove changes inside "actbl3.h". This file is taken care by ACPICA. * Parse both subspace type 1 and subspace type 2 * Remove unnecessary variable initialization * ISR returns IRQ_NONE in case of error v1 * Initial Signed-off-by: Hoan Tran <hotran@xxxxxxx> --- drivers/mailbox/pcc.c | 395 +++++++++++++++++++++++++++++++++++++------------- 1 file changed, 296 insertions(+), 99 deletions(-) diff --git a/drivers/mailbox/pcc.c b/drivers/mailbox/pcc.c index 043828d..58c9a67 100644 --- a/drivers/mailbox/pcc.c +++ b/drivers/mailbox/pcc.c @@ -59,6 +59,7 @@ #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> @@ -68,27 +69,179 @@ #include "mailbox.h" #define MAX_PCC_SUBSPACES 256 +#define MBOX_IRQ_NAME "pcc-mbox" -static struct mbox_chan *pcc_mbox_channels; +/** + * PCC mailbox channel information + * + * @chan: Pointer to mailbox communication channel + * @pcc_doorbell_vaddr: PCC doorbell register address + * @pcc_doorbell_ack_vaddr: PCC doorbell ack register address + * @irq: Interrupt number of the channel + */ +struct pcc_mbox_chan { + struct mbox_chan *chan; + void __iomem *pcc_doorbell_vaddr; + void __iomem *pcc_doorbell_ack_vaddr; + int irq; +}; -/* Array of cached virtual address for doorbell registers */ -static void __iomem **pcc_doorbell_vaddr; +/** + * PCC mailbox controller data + * + * @mb_ctrl: Representation of the communication channel controller + * @mbox_chan: Array of PCC mailbox channels of the controller + * @chans: Array of mailbox communication channels + */ +struct pcc_mbox { + struct mbox_controller mbox_ctrl; + struct pcc_mbox_chan *mbox_chans; + struct mbox_chan *chans; +}; + +static struct pcc_mbox pcc_mbox_ctx = {}; -static struct mbox_controller pcc_mbox_ctrl = {}; /** * get_pcc_channel - Given a PCC subspace idx, get - * the respective mbox_channel. + * the respective pcc mbox_channel. * @id: PCC subspace index. * * Return: ERR_PTR(errno) if error, else pointer - * to mbox channel. + * to pcc mbox channel. */ -static struct mbox_chan *get_pcc_channel(int id) +static struct pcc_mbox_chan *get_pcc_channel(int id) { - if (id < 0 || id > pcc_mbox_ctrl.num_chans) + if (id < 0 || id > pcc_mbox_ctx.mbox_ctrl.num_chans) return ERR_PTR(-ENOENT); - return &pcc_mbox_channels[id]; + return &pcc_mbox_ctx.mbox_chans[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 *id) +{ + struct acpi_generic_address *doorbell_ack; + struct acpi_pcct_hw_reduced *pcct_ss; + struct pcc_mbox_chan *pcc_chan = id; + u64 doorbell_ack_preserve; + struct mbox_chan *chan; + u64 doorbell_ack_write; + u64 doorbell_ack_val; + int ret; + + chan = pcc_chan->chan; + 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; + + doorbell_ack = &pcct2_ss->doorbell_ack_register; + doorbell_ack_preserve = pcct2_ss->ack_preserve_mask; + doorbell_ack_write = pcct2_ss->ack_write_mask; + + ret = read_register(pcc_chan->pcc_doorbell_ack_vaddr, + &doorbell_ack_val, + doorbell_ack->bit_width); + if (ret) + return IRQ_NONE; + + ret = write_register(pcc_chan->pcc_doorbell_ack_vaddr, + (doorbell_ack_val & doorbell_ack_preserve) + | doorbell_ack_write, + doorbell_ack->bit_width); + if (ret) + return IRQ_NONE; + } + + return IRQ_HANDLED; } /** @@ -107,7 +260,8 @@ static struct mbox_chan *get_pcc_channel(int id) struct mbox_chan *pcc_mbox_request_channel(struct mbox_client *cl, int subspace_id) { - struct device *dev = pcc_mbox_ctrl.dev; + struct device *dev = pcc_mbox_ctx.mbox_ctrl.dev; + struct pcc_mbox_chan *pcc_chan; struct mbox_chan *chan; unsigned long flags; @@ -118,8 +272,13 @@ struct mbox_chan *pcc_mbox_request_channel(struct mbox_client *cl, * This returns a pointer to the PCC subspace * for the Client to operate on. */ - chan = get_pcc_channel(subspace_id); + pcc_chan = get_pcc_channel(subspace_id); + if (IS_ERR(pcc_chan)) { + dev_err(dev, "PCC Channel not found for idx: %d\n", subspace_id); + return ERR_PTR(-EBUSY); + } + chan = pcc_chan->chan; if (IS_ERR(chan) || chan->cl) { dev_err(dev, "Channel not found for idx: %d\n", subspace_id); return ERR_PTR(-EBUSY); @@ -135,6 +294,18 @@ struct mbox_chan *pcc_mbox_request_channel(struct mbox_client *cl, if (chan->txdone_method == TXDONE_BY_POLL && cl->knows_txdone) chan->txdone_method |= TXDONE_BY_ACK; + if (pcc_chan->irq > 0) { + int rc; + + rc = devm_request_irq(dev, pcc_chan->irq, pcc_mbox_irq, 0, + MBOX_IRQ_NAME, pcc_chan); + if (unlikely(rc)) { + dev_err(dev, "failed to register PCC interrupt %d\n", + pcc_chan->irq); + chan = ERR_PTR(rc); + } + } + spin_unlock_irqrestore(&chan->lock, flags); return chan; @@ -149,7 +320,9 @@ EXPORT_SYMBOL_GPL(pcc_mbox_request_channel); */ void pcc_mbox_free_channel(struct mbox_chan *chan) { + struct pcc_mbox_chan *pcc_chan; unsigned long flags; + u32 id; if (!chan || !chan->cl) return; @@ -160,69 +333,19 @@ void pcc_mbox_free_channel(struct mbox_chan *chan) if (chan->txdone_method == (TXDONE_BY_POLL | TXDONE_BY_ACK)) chan->txdone_method = TXDONE_BY_POLL; + id = chan - pcc_mbox_ctx.chans; + pcc_chan = get_pcc_channel(id); + if (IS_ERR(pcc_chan)) { + pr_debug("PCC Channel not found for idx: %d\n", id); + } else { + if (pcc_chan->irq > 0) + devm_free_irq(chan->mbox->dev, pcc_chan->irq, chan); + } + spin_unlock_irqrestore(&chan->lock, flags); } 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 @@ -240,36 +363,44 @@ 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 pcc_mbox_chan *pcc_chan; u64 doorbell_preserve; u64 doorbell_val; u64 doorbell_write; - u32 id = chan - pcc_mbox_channels; - int ret = 0; + u32 id = chan - pcc_mbox_ctx.chans; + int ret; - if (id >= pcc_mbox_ctrl.num_chans) { + if (id >= pcc_mbox_ctx.mbox_ctrl.num_chans) { pr_debug("pcc_send_data: Invalid mbox_chan passed\n"); return -ENOENT; } + pcc_chan = get_pcc_channel(id); + if (IS_ERR(pcc_chan)) { + pr_debug("PCC Channel not found for idx: %d\n", id); + return -EBUSY; + } + 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 (pcc_chan->pcc_doorbell_vaddr) { + ret = read_register(pcc_chan->pcc_doorbell_vaddr, &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); + ret = write_register(pcc_chan->pcc_doorbell_vaddr, + (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); + doorbell); } return ret; } @@ -293,11 +424,13 @@ static int parse_pcc_subspace(struct acpi_subtable_header *header, { struct acpi_pcct_hw_reduced *pcct_ss; - if (pcc_mbox_ctrl.num_chans <= MAX_PCC_SUBSPACES) { + if (pcc_mbox_ctx.mbox_ctrl.num_chans <= MAX_PCC_SUBSPACES) { pcct_ss = (struct acpi_pcct_hw_reduced *) header; - if (pcct_ss->header.type != - ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE) { + if ((pcct_ss->header.type != + ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE) + && (pcct_ss->header.type != + ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE_TYPE2)) { pr_err("Incorrect PCC Subspace type detected\n"); return -EINVAL; } @@ -307,6 +440,43 @@ static int parse_pcc_subspace(struct acpi_subtable_header *header, } /** + * pcc_parse_subspace_irq - Parse the PCC IRQ and PCC ACK register + * There should be one entry per PCC client. + * @mbox_chans: Pointer to the PCC mailbox channel data + * @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(struct pcc_mbox_chan *mbox_chans, + struct acpi_pcct_hw_reduced *pcct_ss) +{ + mbox_chans->irq = pcc_map_interrupt(pcct_ss->doorbell_interrupt, + (u32)pcct_ss->flags); + if (mbox_chans->irq <= 0) { + pr_err("PCC GSI %d not registered\n", + pcct_ss->doorbell_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; + + mbox_chans->pcc_doorbell_ack_vaddr = acpi_os_ioremap( + pcct2_ss->doorbell_ack_register.address, + pcct2_ss->doorbell_ack_register.bit_width / 8); + if (!mbox_chans->pcc_doorbell_ack_vaddr) { + 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. @@ -316,7 +486,8 @@ static int __init acpi_pcc_probe(void) acpi_size pcct_tbl_header_size; struct acpi_table_header *pcct_tbl; struct acpi_subtable_header *pcct_entry; - int count, i; + struct acpi_table_pcct *acpi_pcct_tbl; + int count, i, rc; acpi_status status = AE_OK; /* Search for PCCT */ @@ -334,22 +505,28 @@ static int __init acpi_pcc_probe(void) ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE, parse_pcc_subspace, MAX_PCC_SUBSPACES); + count += acpi_table_parse_entries(ACPI_SIG_PCCT, + sizeof(struct acpi_table_pcct), + ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE_TYPE2, + parse_pcc_subspace, MAX_PCC_SUBSPACES); + if (count <= 0) { pr_err("Error parsing PCC subspaces from PCCT\n"); return -EINVAL; } - pcc_mbox_channels = kzalloc(sizeof(struct mbox_chan) * - count, GFP_KERNEL); + pcc_mbox_ctx.chans = kzalloc(sizeof(struct mbox_chan) * + count, GFP_KERNEL); - if (!pcc_mbox_channels) { + if (!pcc_mbox_ctx.chans) { 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) { - kfree(pcc_mbox_channels); + pcc_mbox_ctx.mbox_chans = kzalloc(sizeof(struct pcc_mbox_chan) * + count, GFP_KERNEL); + if (!pcc_mbox_ctx.mbox_chans) { + pr_err("Could not allocate space for PCC mbox channel data\n"); return -ENOMEM; } @@ -357,24 +534,44 @@ static int __init acpi_pcc_probe(void) 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_ctx.mbox_ctrl.txdone_irq = true; + 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; + + pcc_mbox_ctx.chans[i].con_priv = pcct_entry; + pcc_mbox_ctx.chans[i].mbox = &pcc_mbox_ctx.mbox_ctrl; + + pcct_ss = (struct acpi_pcct_hw_reduced *) pcct_entry; + + pcc_mbox_ctx.mbox_chans[i].chan = &pcc_mbox_ctx.chans[i]; + if (pcc_mbox_ctx.mbox_ctrl.txdone_irq) { + rc = pcc_parse_subspace_irq(&pcc_mbox_ctx.mbox_chans[i], + pcct_ss); + if (rc < 0) + return rc; + } /* 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, + if (db_reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) { + pcc_mbox_ctx.mbox_chans[i].pcc_doorbell_vaddr = + 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; + pcc_mbox_ctx.mbox_ctrl.num_chans = count; - pr_info("Detected %d PCC Subspaces\n", pcc_mbox_ctrl.num_chans); + pr_info("Detected %d PCC Subspaces\n", + pcc_mbox_ctx.mbox_ctrl.num_chans); return 0; } @@ -394,12 +591,12 @@ 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; + pcc_mbox_ctx.mbox_ctrl.chans = pcc_mbox_ctx.chans; + pcc_mbox_ctx.mbox_ctrl.ops = &pcc_chan_ops; + pcc_mbox_ctx.mbox_ctrl.dev = &pdev->dev; pr_info("Registering PCC driver as Mailbox controller\n"); - ret = mbox_controller_register(&pcc_mbox_ctrl); + ret = mbox_controller_register(&pcc_mbox_ctx.mbox_ctrl); if (ret) { pr_err("Err registering PCC as Mailbox controller: %d\n", ret); -- 1.9.1 -- CONFIDENTIALITY NOTICE: This e-mail message, including any attachments, is for the sole use of the intended recipient(s) and contains information that is confidential and proprietary to Applied Micro Circuits Corporation or its subsidiaries. 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