mailbox: pcc: Support HW-Reduced Communication Subspace type 2
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. Signed-off-by: Hoan Tran <hotran@apm.com> Reviewed-by: Prashanth Prakash <pprakash@codeaurora.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>hifive-unleashed-5.1
hotran
Rafael J. Wysocki
parent
3eab887a55
commit
aca314efb1
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@ -59,6 +59,7 @@
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#include <linux/delay.h>
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#include <linux/io.h>
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#include <linux/init.h>
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#include <linux/interrupt.h>
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#include <linux/list.h>
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#include <linux/platform_device.h>
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#include <linux/mailbox_controller.h>
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@ -68,11 +69,16 @@
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#include "mailbox.h"
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#define MAX_PCC_SUBSPACES 256
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#define MBOX_IRQ_NAME "pcc-mbox"
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static struct mbox_chan *pcc_mbox_channels;
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/* Array of cached virtual address for doorbell registers */
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static void __iomem **pcc_doorbell_vaddr;
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/* Array of cached virtual address for doorbell ack registers */
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static void __iomem **pcc_doorbell_ack_vaddr;
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/* Array of doorbell interrupts */
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static int *pcc_doorbell_irq;
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static struct mbox_controller pcc_mbox_ctrl = {};
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/**
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@ -91,79 +97,6 @@ static struct mbox_chan *get_pcc_channel(int id)
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return &pcc_mbox_channels[id];
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}
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/**
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* pcc_mbox_request_channel - PCC clients call this function to
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* request a pointer to their PCC subspace, from which they
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* can get the details of communicating with the remote.
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* @cl: Pointer to Mailbox client, so we know where to bind the
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* Channel.
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* @subspace_id: The PCC Subspace index as parsed in the PCC client
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* ACPI package. This is used to lookup the array of PCC
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* subspaces as parsed by the PCC Mailbox controller.
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*
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* Return: Pointer to the Mailbox Channel if successful or
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* ERR_PTR.
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*/
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struct mbox_chan *pcc_mbox_request_channel(struct mbox_client *cl,
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int subspace_id)
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{
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struct device *dev = pcc_mbox_ctrl.dev;
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struct mbox_chan *chan;
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unsigned long flags;
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/*
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* Each PCC Subspace is a Mailbox Channel.
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* The PCC Clients get their PCC Subspace ID
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* from their own tables and pass it here.
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* This returns a pointer to the PCC subspace
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* for the Client to operate on.
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*/
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chan = get_pcc_channel(subspace_id);
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if (IS_ERR(chan) || chan->cl) {
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dev_err(dev, "Channel not found for idx: %d\n", subspace_id);
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return ERR_PTR(-EBUSY);
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}
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spin_lock_irqsave(&chan->lock, flags);
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chan->msg_free = 0;
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chan->msg_count = 0;
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chan->active_req = NULL;
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chan->cl = cl;
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init_completion(&chan->tx_complete);
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if (chan->txdone_method == TXDONE_BY_POLL && cl->knows_txdone)
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chan->txdone_method |= TXDONE_BY_ACK;
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spin_unlock_irqrestore(&chan->lock, flags);
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return chan;
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}
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EXPORT_SYMBOL_GPL(pcc_mbox_request_channel);
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/**
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* pcc_mbox_free_channel - Clients call this to free their Channel.
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*
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* @chan: Pointer to the mailbox channel as returned by
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* pcc_mbox_request_channel()
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*/
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void pcc_mbox_free_channel(struct mbox_chan *chan)
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{
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unsigned long flags;
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if (!chan || !chan->cl)
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return;
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spin_lock_irqsave(&chan->lock, flags);
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chan->cl = NULL;
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chan->active_req = NULL;
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if (chan->txdone_method == (TXDONE_BY_POLL | TXDONE_BY_ACK))
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chan->txdone_method = TXDONE_BY_POLL;
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spin_unlock_irqrestore(&chan->lock, flags);
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}
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EXPORT_SYMBOL_GPL(pcc_mbox_free_channel);
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/*
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* PCC can be used with perf critical drivers such as CPPC
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* So it makes sense to locally cache the virtual address and
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@ -224,6 +157,167 @@ static int write_register(void __iomem *vaddr, u64 val, unsigned int bit_width)
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return ret_val;
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}
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/**
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* pcc_map_interrupt - Map a PCC subspace GSI to a linux IRQ number
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* @interrupt: GSI number.
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* @flags: interrupt flags
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*
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* Returns: a valid linux IRQ number on success
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* 0 or -EINVAL on failure
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*/
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static int pcc_map_interrupt(u32 interrupt, u32 flags)
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{
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int trigger, polarity;
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if (!interrupt)
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return 0;
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trigger = (flags & ACPI_PCCT_INTERRUPT_MODE) ? ACPI_EDGE_SENSITIVE
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: ACPI_LEVEL_SENSITIVE;
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polarity = (flags & ACPI_PCCT_INTERRUPT_POLARITY) ? ACPI_ACTIVE_LOW
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: ACPI_ACTIVE_HIGH;
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return acpi_register_gsi(NULL, interrupt, trigger, polarity);
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}
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/**
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* pcc_mbox_irq - PCC mailbox interrupt handler
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*/
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static irqreturn_t pcc_mbox_irq(int irq, void *p)
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{
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struct acpi_generic_address *doorbell_ack;
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struct acpi_pcct_hw_reduced *pcct_ss;
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struct mbox_chan *chan = p;
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u64 doorbell_ack_preserve;
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u64 doorbell_ack_write;
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u64 doorbell_ack_val;
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int ret;
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pcct_ss = chan->con_priv;
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mbox_chan_received_data(chan, NULL);
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if (pcct_ss->header.type == ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE_TYPE2) {
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struct acpi_pcct_hw_reduced_type2 *pcct2_ss = chan->con_priv;
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u32 id = chan - pcc_mbox_channels;
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doorbell_ack = &pcct2_ss->doorbell_ack_register;
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doorbell_ack_preserve = pcct2_ss->ack_preserve_mask;
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doorbell_ack_write = pcct2_ss->ack_write_mask;
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ret = read_register(pcc_doorbell_ack_vaddr[id],
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&doorbell_ack_val,
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doorbell_ack->bit_width);
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if (ret)
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return IRQ_NONE;
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ret = write_register(pcc_doorbell_ack_vaddr[id],
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(doorbell_ack_val & doorbell_ack_preserve)
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| doorbell_ack_write,
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doorbell_ack->bit_width);
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if (ret)
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return IRQ_NONE;
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}
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return IRQ_HANDLED;
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}
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/**
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* pcc_mbox_request_channel - PCC clients call this function to
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* request a pointer to their PCC subspace, from which they
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* can get the details of communicating with the remote.
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* @cl: Pointer to Mailbox client, so we know where to bind the
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* Channel.
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* @subspace_id: The PCC Subspace index as parsed in the PCC client
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* ACPI package. This is used to lookup the array of PCC
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* subspaces as parsed by the PCC Mailbox controller.
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*
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* Return: Pointer to the Mailbox Channel if successful or
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* ERR_PTR.
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*/
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struct mbox_chan *pcc_mbox_request_channel(struct mbox_client *cl,
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int subspace_id)
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{
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struct device *dev = pcc_mbox_ctrl.dev;
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struct mbox_chan *chan;
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unsigned long flags;
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/*
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* Each PCC Subspace is a Mailbox Channel.
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* The PCC Clients get their PCC Subspace ID
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* from their own tables and pass it here.
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* This returns a pointer to the PCC subspace
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* for the Client to operate on.
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*/
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chan = get_pcc_channel(subspace_id);
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if (IS_ERR(chan) || chan->cl) {
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dev_err(dev, "Channel not found for idx: %d\n", subspace_id);
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return ERR_PTR(-EBUSY);
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}
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spin_lock_irqsave(&chan->lock, flags);
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chan->msg_free = 0;
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chan->msg_count = 0;
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chan->active_req = NULL;
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chan->cl = cl;
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init_completion(&chan->tx_complete);
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if (chan->txdone_method == TXDONE_BY_POLL && cl->knows_txdone)
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chan->txdone_method |= TXDONE_BY_ACK;
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if (pcc_doorbell_irq[subspace_id] > 0) {
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int rc;
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rc = devm_request_irq(dev, pcc_doorbell_irq[subspace_id],
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pcc_mbox_irq, 0, MBOX_IRQ_NAME, chan);
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if (unlikely(rc)) {
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dev_err(dev, "failed to register PCC interrupt %d\n",
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pcc_doorbell_irq[subspace_id]);
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chan = ERR_PTR(rc);
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}
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}
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spin_unlock_irqrestore(&chan->lock, flags);
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return chan;
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}
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EXPORT_SYMBOL_GPL(pcc_mbox_request_channel);
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/**
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* pcc_mbox_free_channel - Clients call this to free their Channel.
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*
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* @chan: Pointer to the mailbox channel as returned by
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* pcc_mbox_request_channel()
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*/
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void pcc_mbox_free_channel(struct mbox_chan *chan)
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{
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u32 id = chan - pcc_mbox_channels;
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unsigned long flags;
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if (!chan || !chan->cl)
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return;
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if (id >= pcc_mbox_ctrl.num_chans) {
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pr_debug("pcc_mbox_free_channel: Invalid mbox_chan passed\n");
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return;
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}
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spin_lock_irqsave(&chan->lock, flags);
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chan->cl = NULL;
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chan->active_req = NULL;
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if (chan->txdone_method == (TXDONE_BY_POLL | TXDONE_BY_ACK))
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chan->txdone_method = TXDONE_BY_POLL;
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if (pcc_doorbell_irq[id] > 0)
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devm_free_irq(chan->mbox->dev, pcc_doorbell_irq[id], chan);
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spin_unlock_irqrestore(&chan->lock, flags);
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}
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EXPORT_SYMBOL_GPL(pcc_mbox_free_channel);
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/**
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* pcc_send_data - Called from Mailbox Controller code. Used
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* here only to ring the channel doorbell. The PCC client
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@ -296,8 +390,10 @@ static int parse_pcc_subspace(struct acpi_subtable_header *header,
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if (pcc_mbox_ctrl.num_chans <= MAX_PCC_SUBSPACES) {
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pcct_ss = (struct acpi_pcct_hw_reduced *) header;
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if (pcct_ss->header.type !=
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ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE) {
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if ((pcct_ss->header.type !=
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ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE)
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&& (pcct_ss->header.type !=
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ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE_TYPE2)) {
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pr_err("Incorrect PCC Subspace type detected\n");
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return -EINVAL;
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}
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@ -306,6 +402,43 @@ static int parse_pcc_subspace(struct acpi_subtable_header *header,
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return 0;
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}
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/**
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* pcc_parse_subspace_irq - Parse the PCC IRQ and PCC ACK register
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* There should be one entry per PCC client.
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* @id: PCC subspace index.
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* @pcct_ss: Pointer to the ACPI subtable header under the PCCT.
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*
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* Return: 0 for Success, else errno.
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*
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* This gets called for each entry in the PCC table.
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*/
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static int pcc_parse_subspace_irq(int id,
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struct acpi_pcct_hw_reduced *pcct_ss)
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{
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pcc_doorbell_irq[id] = pcc_map_interrupt(pcct_ss->doorbell_interrupt,
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(u32)pcct_ss->flags);
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if (pcc_doorbell_irq[id] <= 0) {
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pr_err("PCC GSI %d not registered\n",
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pcct_ss->doorbell_interrupt);
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return -EINVAL;
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}
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if (pcct_ss->header.type
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== ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE_TYPE2) {
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struct acpi_pcct_hw_reduced_type2 *pcct2_ss = (void *)pcct_ss;
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pcc_doorbell_ack_vaddr[id] = acpi_os_ioremap(
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pcct2_ss->doorbell_ack_register.address,
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pcct2_ss->doorbell_ack_register.bit_width / 8);
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if (!pcc_doorbell_ack_vaddr[id]) {
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pr_err("Failed to ioremap PCC ACK register\n");
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return -ENOMEM;
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}
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}
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return 0;
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}
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/**
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* acpi_pcc_probe - Parse the ACPI tree for the PCCT.
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*
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@ -316,7 +449,9 @@ static int __init acpi_pcc_probe(void)
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acpi_size pcct_tbl_header_size;
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struct acpi_table_header *pcct_tbl;
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struct acpi_subtable_header *pcct_entry;
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int count, i;
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struct acpi_table_pcct *acpi_pcct_tbl;
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int count, i, rc;
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int sum = 0;
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acpi_status status = AE_OK;
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/* Search for PCCT */
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@ -333,37 +468,66 @@ static int __init acpi_pcc_probe(void)
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sizeof(struct acpi_table_pcct),
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ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE,
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parse_pcc_subspace, MAX_PCC_SUBSPACES);
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sum += (count > 0) ? count : 0;
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if (count <= 0) {
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count = acpi_table_parse_entries(ACPI_SIG_PCCT,
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sizeof(struct acpi_table_pcct),
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ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE_TYPE2,
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parse_pcc_subspace, MAX_PCC_SUBSPACES);
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sum += (count > 0) ? count : 0;
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if (sum == 0 || sum >= MAX_PCC_SUBSPACES) {
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pr_err("Error parsing PCC subspaces from PCCT\n");
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return -EINVAL;
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}
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pcc_mbox_channels = kzalloc(sizeof(struct mbox_chan) *
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count, GFP_KERNEL);
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sum, GFP_KERNEL);
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if (!pcc_mbox_channels) {
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pr_err("Could not allocate space for PCC mbox channels\n");
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return -ENOMEM;
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}
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pcc_doorbell_vaddr = kcalloc(count, sizeof(void *), GFP_KERNEL);
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pcc_doorbell_vaddr = kcalloc(sum, sizeof(void *), GFP_KERNEL);
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if (!pcc_doorbell_vaddr) {
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kfree(pcc_mbox_channels);
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return -ENOMEM;
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rc = -ENOMEM;
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goto err_free_mbox;
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}
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pcc_doorbell_ack_vaddr = kcalloc(sum, sizeof(void *), GFP_KERNEL);
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if (!pcc_doorbell_ack_vaddr) {
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rc = -ENOMEM;
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goto err_free_db_vaddr;
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}
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pcc_doorbell_irq = kcalloc(sum, sizeof(int), GFP_KERNEL);
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if (!pcc_doorbell_irq) {
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rc = -ENOMEM;
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goto err_free_db_ack_vaddr;
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}
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/* Point to the first PCC subspace entry */
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pcct_entry = (struct acpi_subtable_header *) (
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(unsigned long) pcct_tbl + sizeof(struct acpi_table_pcct));
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for (i = 0; i < count; i++) {
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acpi_pcct_tbl = (struct acpi_table_pcct *) pcct_tbl;
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if (acpi_pcct_tbl->flags & ACPI_PCCT_DOORBELL)
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pcc_mbox_ctrl.txdone_irq = true;
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for (i = 0; i < sum; i++) {
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struct acpi_generic_address *db_reg;
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struct acpi_pcct_hw_reduced *pcct_ss;
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pcc_mbox_channels[i].con_priv = pcct_entry;
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pcct_ss = (struct acpi_pcct_hw_reduced *) pcct_entry;
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if (pcc_mbox_ctrl.txdone_irq) {
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rc = pcc_parse_subspace_irq(i, pcct_ss);
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if (rc < 0)
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goto err;
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}
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/* If doorbell is in system memory cache the virt address */
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pcct_ss = (struct acpi_pcct_hw_reduced *)pcct_entry;
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db_reg = &pcct_ss->doorbell_register;
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if (db_reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY)
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pcc_doorbell_vaddr[i] = acpi_os_ioremap(db_reg->address,
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@ -372,11 +536,21 @@ static int __init acpi_pcc_probe(void)
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((unsigned long) pcct_entry + pcct_entry->length);
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}
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pcc_mbox_ctrl.num_chans = count;
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pcc_mbox_ctrl.num_chans = sum;
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pr_info("Detected %d PCC Subspaces\n", pcc_mbox_ctrl.num_chans);
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return 0;
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err:
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kfree(pcc_doorbell_irq);
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err_free_db_ack_vaddr:
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kfree(pcc_doorbell_ack_vaddr);
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err_free_db_vaddr:
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kfree(pcc_doorbell_vaddr);
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err_free_mbox:
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kfree(pcc_mbox_channels);
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return rc;
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}
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/**
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