diff options
Diffstat (limited to 'drivers/soc/qcom/rpmh-rsc.c')
| -rw-r--r-- | drivers/soc/qcom/rpmh-rsc.c | 1035 |
1 files changed, 1035 insertions, 0 deletions
diff --git a/drivers/soc/qcom/rpmh-rsc.c b/drivers/soc/qcom/rpmh-rsc.c new file mode 100644 index 000000000..a297911af --- /dev/null +++ b/drivers/soc/qcom/rpmh-rsc.c @@ -0,0 +1,1035 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2016-2018, The Linux Foundation. All rights reserved. + */ + +#define pr_fmt(fmt) "%s " fmt, KBUILD_MODNAME + +#include <linux/atomic.h> +#include <linux/cpu_pm.h> +#include <linux/delay.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/iopoll.h> +#include <linux/kernel.h> +#include <linux/list.h> +#include <linux/of.h> +#include <linux/of_irq.h> +#include <linux/of_platform.h> +#include <linux/platform_device.h> +#include <linux/slab.h> +#include <linux/spinlock.h> +#include <linux/wait.h> + +#include <soc/qcom/cmd-db.h> +#include <soc/qcom/tcs.h> +#include <dt-bindings/soc/qcom,rpmh-rsc.h> + +#include "rpmh-internal.h" + +#define CREATE_TRACE_POINTS +#include "trace-rpmh.h" + +#define RSC_DRV_TCS_OFFSET 672 +#define RSC_DRV_CMD_OFFSET 20 + +/* DRV HW Solver Configuration Information Register */ +#define DRV_SOLVER_CONFIG 0x04 +#define DRV_HW_SOLVER_MASK 1 +#define DRV_HW_SOLVER_SHIFT 24 + +/* DRV TCS Configuration Information Register */ +#define DRV_PRNT_CHLD_CONFIG 0x0C +#define DRV_NUM_TCS_MASK 0x3F +#define DRV_NUM_TCS_SHIFT 6 +#define DRV_NCPT_MASK 0x1F +#define DRV_NCPT_SHIFT 27 + +/* Offsets for common TCS Registers, one bit per TCS */ +#define RSC_DRV_IRQ_ENABLE 0x00 +#define RSC_DRV_IRQ_STATUS 0x04 +#define RSC_DRV_IRQ_CLEAR 0x08 /* w/o; write 1 to clear */ + +/* + * Offsets for per TCS Registers. + * + * TCSes start at 0x10 from tcs_base and are stored one after another. + * Multiply tcs_id by RSC_DRV_TCS_OFFSET to find a given TCS and add one + * of the below to find a register. + */ +#define RSC_DRV_CMD_WAIT_FOR_CMPL 0x10 /* 1 bit per command */ +#define RSC_DRV_CONTROL 0x14 +#define RSC_DRV_STATUS 0x18 /* zero if tcs is busy */ +#define RSC_DRV_CMD_ENABLE 0x1C /* 1 bit per command */ + +/* + * Offsets for per command in a TCS. + * + * Commands (up to 16) start at 0x30 in a TCS; multiply command index + * by RSC_DRV_CMD_OFFSET and add one of the below to find a register. + */ +#define RSC_DRV_CMD_MSGID 0x30 +#define RSC_DRV_CMD_ADDR 0x34 +#define RSC_DRV_CMD_DATA 0x38 +#define RSC_DRV_CMD_STATUS 0x3C +#define RSC_DRV_CMD_RESP_DATA 0x40 + +#define TCS_AMC_MODE_ENABLE BIT(16) +#define TCS_AMC_MODE_TRIGGER BIT(24) + +/* TCS CMD register bit mask */ +#define CMD_MSGID_LEN 8 +#define CMD_MSGID_RESP_REQ BIT(8) +#define CMD_MSGID_WRITE BIT(16) +#define CMD_STATUS_ISSUED BIT(8) +#define CMD_STATUS_COMPL BIT(16) + +/* + * Here's a high level overview of how all the registers in RPMH work + * together: + * + * - The main rpmh-rsc address is the base of a register space that can + * be used to find overall configuration of the hardware + * (DRV_PRNT_CHLD_CONFIG). Also found within the rpmh-rsc register + * space are all the TCS blocks. The offset of the TCS blocks is + * specified in the device tree by "qcom,tcs-offset" and used to + * compute tcs_base. + * - TCS blocks come one after another. Type, count, and order are + * specified by the device tree as "qcom,tcs-config". + * - Each TCS block has some registers, then space for up to 16 commands. + * Note that though address space is reserved for 16 commands, fewer + * might be present. See ncpt (num cmds per TCS). + * + * Here's a picture: + * + * +---------------------------------------------------+ + * |RSC | + * | ctrl | + * | | + * | Drvs: | + * | +-----------------------------------------------+ | + * | |DRV0 | | + * | | ctrl/config | | + * | | IRQ | | + * | | | | + * | | TCSes: | | + * | | +------------------------------------------+ | | + * | | |TCS0 | | | | | | | | | | | | | | | + * | | | ctrl | 0| 1| 2| 3| 4| 5| .| .| .| .|14|15| | | + * | | | | | | | | | | | | | | | | | | + * | | +------------------------------------------+ | | + * | | +------------------------------------------+ | | + * | | |TCS1 | | | | | | | | | | | | | | | + * | | | ctrl | 0| 1| 2| 3| 4| 5| .| .| .| .|14|15| | | + * | | | | | | | | | | | | | | | | | | + * | | +------------------------------------------+ | | + * | | +------------------------------------------+ | | + * | | |TCS2 | | | | | | | | | | | | | | | + * | | | ctrl | 0| 1| 2| 3| 4| 5| .| .| .| .|14|15| | | + * | | | | | | | | | | | | | | | | | | + * | | +------------------------------------------+ | | + * | | ...... | | + * | +-----------------------------------------------+ | + * | +-----------------------------------------------+ | + * | |DRV1 | | + * | | (same as DRV0) | | + * | +-----------------------------------------------+ | + * | ...... | + * +---------------------------------------------------+ + */ + +static inline void __iomem * +tcs_reg_addr(const struct rsc_drv *drv, int reg, int tcs_id) +{ + return drv->tcs_base + RSC_DRV_TCS_OFFSET * tcs_id + reg; +} + +static inline void __iomem * +tcs_cmd_addr(const struct rsc_drv *drv, int reg, int tcs_id, int cmd_id) +{ + return tcs_reg_addr(drv, reg, tcs_id) + RSC_DRV_CMD_OFFSET * cmd_id; +} + +static u32 read_tcs_cmd(const struct rsc_drv *drv, int reg, int tcs_id, + int cmd_id) +{ + return readl_relaxed(tcs_cmd_addr(drv, reg, tcs_id, cmd_id)); +} + +static u32 read_tcs_reg(const struct rsc_drv *drv, int reg, int tcs_id) +{ + return readl_relaxed(tcs_reg_addr(drv, reg, tcs_id)); +} + +static void write_tcs_cmd(const struct rsc_drv *drv, int reg, int tcs_id, + int cmd_id, u32 data) +{ + writel_relaxed(data, tcs_cmd_addr(drv, reg, tcs_id, cmd_id)); +} + +static void write_tcs_reg(const struct rsc_drv *drv, int reg, int tcs_id, + u32 data) +{ + writel_relaxed(data, tcs_reg_addr(drv, reg, tcs_id)); +} + +static void write_tcs_reg_sync(const struct rsc_drv *drv, int reg, int tcs_id, + u32 data) +{ + int i; + + writel(data, tcs_reg_addr(drv, reg, tcs_id)); + + /* + * Wait until we read back the same value. Use a counter rather than + * ktime for timeout since this may be called after timekeeping stops. + */ + for (i = 0; i < USEC_PER_SEC; i++) { + if (readl(tcs_reg_addr(drv, reg, tcs_id)) == data) + return; + udelay(1); + } + pr_err("%s: error writing %#x to %d:%#x\n", drv->name, + data, tcs_id, reg); +} + +/** + * tcs_is_free() - Return if a TCS is totally free. + * @drv: The RSC controller. + * @tcs_id: The global ID of this TCS. + * + * Returns true if nobody has claimed this TCS (by setting tcs_in_use). + * + * Context: Must be called with the drv->lock held. + * + * Return: true if the given TCS is free. + */ +static bool tcs_is_free(struct rsc_drv *drv, int tcs_id) +{ + return !test_bit(tcs_id, drv->tcs_in_use); +} + +/** + * tcs_invalidate() - Invalidate all TCSes of the given type (sleep or wake). + * @drv: The RSC controller. + * @type: SLEEP_TCS or WAKE_TCS + * + * This will clear the "slots" variable of the given tcs_group and also + * tell the hardware to forget about all entries. + * + * The caller must ensure that no other RPMH actions are happening when this + * function is called, since otherwise the device may immediately become + * used again even before this function exits. + */ +static void tcs_invalidate(struct rsc_drv *drv, int type) +{ + int m; + struct tcs_group *tcs = &drv->tcs[type]; + + /* Caller ensures nobody else is running so no lock */ + if (bitmap_empty(tcs->slots, MAX_TCS_SLOTS)) + return; + + for (m = tcs->offset; m < tcs->offset + tcs->num_tcs; m++) { + write_tcs_reg_sync(drv, RSC_DRV_CMD_ENABLE, m, 0); + write_tcs_reg_sync(drv, RSC_DRV_CMD_WAIT_FOR_CMPL, m, 0); + } + bitmap_zero(tcs->slots, MAX_TCS_SLOTS); +} + +/** + * rpmh_rsc_invalidate() - Invalidate sleep and wake TCSes. + * @drv: The RSC controller. + * + * The caller must ensure that no other RPMH actions are happening when this + * function is called, since otherwise the device may immediately become + * used again even before this function exits. + */ +void rpmh_rsc_invalidate(struct rsc_drv *drv) +{ + tcs_invalidate(drv, SLEEP_TCS); + tcs_invalidate(drv, WAKE_TCS); +} + +/** + * get_tcs_for_msg() - Get the tcs_group used to send the given message. + * @drv: The RSC controller. + * @msg: The message we want to send. + * + * This is normally pretty straightforward except if we are trying to send + * an ACTIVE_ONLY message but don't have any active_only TCSes. + * + * Return: A pointer to a tcs_group or an ERR_PTR. + */ +static struct tcs_group *get_tcs_for_msg(struct rsc_drv *drv, + const struct tcs_request *msg) +{ + int type; + struct tcs_group *tcs; + + switch (msg->state) { + case RPMH_ACTIVE_ONLY_STATE: + type = ACTIVE_TCS; + break; + case RPMH_WAKE_ONLY_STATE: + type = WAKE_TCS; + break; + case RPMH_SLEEP_STATE: + type = SLEEP_TCS; + break; + default: + return ERR_PTR(-EINVAL); + } + + /* + * If we are making an active request on a RSC that does not have a + * dedicated TCS for active state use, then re-purpose a wake TCS to + * send active votes. This is safe because we ensure any active-only + * transfers have finished before we use it (maybe by running from + * the last CPU in PM code). + */ + tcs = &drv->tcs[type]; + if (msg->state == RPMH_ACTIVE_ONLY_STATE && !tcs->num_tcs) + tcs = &drv->tcs[WAKE_TCS]; + + return tcs; +} + +/** + * get_req_from_tcs() - Get a stashed request that was xfering on the given TCS. + * @drv: The RSC controller. + * @tcs_id: The global ID of this TCS. + * + * For ACTIVE_ONLY transfers we want to call back into the client when the + * transfer finishes. To do this we need the "request" that the client + * originally provided us. This function grabs the request that we stashed + * when we started the transfer. + * + * This only makes sense for ACTIVE_ONLY transfers since those are the only + * ones we track sending (the only ones we enable interrupts for and the only + * ones we call back to the client for). + * + * Return: The stashed request. + */ +static const struct tcs_request *get_req_from_tcs(struct rsc_drv *drv, + int tcs_id) +{ + struct tcs_group *tcs; + int i; + + for (i = 0; i < TCS_TYPE_NR; i++) { + tcs = &drv->tcs[i]; + if (tcs->mask & BIT(tcs_id)) + return tcs->req[tcs_id - tcs->offset]; + } + + return NULL; +} + +/** + * __tcs_set_trigger() - Start xfer on a TCS or unset trigger on a borrowed TCS + * @drv: The controller. + * @tcs_id: The global ID of this TCS. + * @trigger: If true then untrigger/retrigger. If false then just untrigger. + * + * In the normal case we only ever call with "trigger=true" to start a + * transfer. That will un-trigger/disable the TCS from the last transfer + * then trigger/enable for this transfer. + * + * If we borrowed a wake TCS for an active-only transfer we'll also call + * this function with "trigger=false" to just do the un-trigger/disable + * before using the TCS for wake purposes again. + * + * Note that the AP is only in charge of triggering active-only transfers. + * The AP never triggers sleep/wake values using this function. + */ +static void __tcs_set_trigger(struct rsc_drv *drv, int tcs_id, bool trigger) +{ + u32 enable; + + /* + * HW req: Clear the DRV_CONTROL and enable TCS again + * While clearing ensure that the AMC mode trigger is cleared + * and then the mode enable is cleared. + */ + enable = read_tcs_reg(drv, RSC_DRV_CONTROL, tcs_id); + enable &= ~TCS_AMC_MODE_TRIGGER; + write_tcs_reg_sync(drv, RSC_DRV_CONTROL, tcs_id, enable); + enable &= ~TCS_AMC_MODE_ENABLE; + write_tcs_reg_sync(drv, RSC_DRV_CONTROL, tcs_id, enable); + + if (trigger) { + /* Enable the AMC mode on the TCS and then trigger the TCS */ + enable = TCS_AMC_MODE_ENABLE; + write_tcs_reg_sync(drv, RSC_DRV_CONTROL, tcs_id, enable); + enable |= TCS_AMC_MODE_TRIGGER; + write_tcs_reg_sync(drv, RSC_DRV_CONTROL, tcs_id, enable); + } +} + +/** + * enable_tcs_irq() - Enable or disable interrupts on the given TCS. + * @drv: The controller. + * @tcs_id: The global ID of this TCS. + * @enable: If true then enable; if false then disable + * + * We only ever call this when we borrow a wake TCS for an active-only + * transfer. For active-only TCSes interrupts are always left enabled. + */ +static void enable_tcs_irq(struct rsc_drv *drv, int tcs_id, bool enable) +{ + u32 data; + + data = readl_relaxed(drv->tcs_base + RSC_DRV_IRQ_ENABLE); + if (enable) + data |= BIT(tcs_id); + else + data &= ~BIT(tcs_id); + writel_relaxed(data, drv->tcs_base + RSC_DRV_IRQ_ENABLE); +} + +/** + * tcs_tx_done() - TX Done interrupt handler. + * @irq: The IRQ number (ignored). + * @p: Pointer to "struct rsc_drv". + * + * Called for ACTIVE_ONLY transfers (those are the only ones we enable the + * IRQ for) when a transfer is done. + * + * Return: IRQ_HANDLED + */ +static irqreturn_t tcs_tx_done(int irq, void *p) +{ + struct rsc_drv *drv = p; + int i, j, err = 0; + unsigned long irq_status; + const struct tcs_request *req; + struct tcs_cmd *cmd; + + irq_status = readl_relaxed(drv->tcs_base + RSC_DRV_IRQ_STATUS); + + for_each_set_bit(i, &irq_status, BITS_PER_LONG) { + req = get_req_from_tcs(drv, i); + if (!req) { + WARN_ON(1); + goto skip; + } + + err = 0; + for (j = 0; j < req->num_cmds; j++) { + u32 sts; + + cmd = &req->cmds[j]; + sts = read_tcs_cmd(drv, RSC_DRV_CMD_STATUS, i, j); + if (!(sts & CMD_STATUS_ISSUED) || + ((req->wait_for_compl || cmd->wait) && + !(sts & CMD_STATUS_COMPL))) { + pr_err("Incomplete request: %s: addr=%#x data=%#x", + drv->name, cmd->addr, cmd->data); + err = -EIO; + } + } + + trace_rpmh_tx_done(drv, i, req, err); + + /* + * If wake tcs was re-purposed for sending active + * votes, clear AMC trigger & enable modes and + * disable interrupt for this TCS + */ + if (!drv->tcs[ACTIVE_TCS].num_tcs) + __tcs_set_trigger(drv, i, false); +skip: + /* Reclaim the TCS */ + write_tcs_reg(drv, RSC_DRV_CMD_ENABLE, i, 0); + write_tcs_reg(drv, RSC_DRV_CMD_WAIT_FOR_CMPL, i, 0); + writel_relaxed(BIT(i), drv->tcs_base + RSC_DRV_IRQ_CLEAR); + spin_lock(&drv->lock); + clear_bit(i, drv->tcs_in_use); + /* + * Disable interrupt for WAKE TCS to avoid being + * spammed with interrupts coming when the solver + * sends its wake votes. + */ + if (!drv->tcs[ACTIVE_TCS].num_tcs) + enable_tcs_irq(drv, i, false); + spin_unlock(&drv->lock); + wake_up(&drv->tcs_wait); + if (req) + rpmh_tx_done(req, err); + } + + return IRQ_HANDLED; +} + +/** + * __tcs_buffer_write() - Write to TCS hardware from a request; don't trigger. + * @drv: The controller. + * @tcs_id: The global ID of this TCS. + * @cmd_id: The index within the TCS to start writing. + * @msg: The message we want to send, which will contain several addr/data + * pairs to program (but few enough that they all fit in one TCS). + * + * This is used for all types of transfers (active, sleep, and wake). + */ +static void __tcs_buffer_write(struct rsc_drv *drv, int tcs_id, int cmd_id, + const struct tcs_request *msg) +{ + u32 msgid, cmd_msgid; + u32 cmd_enable = 0; + u32 cmd_complete; + struct tcs_cmd *cmd; + int i, j; + + cmd_msgid = CMD_MSGID_LEN; + cmd_msgid |= msg->wait_for_compl ? CMD_MSGID_RESP_REQ : 0; + cmd_msgid |= CMD_MSGID_WRITE; + + cmd_complete = read_tcs_reg(drv, RSC_DRV_CMD_WAIT_FOR_CMPL, tcs_id); + + for (i = 0, j = cmd_id; i < msg->num_cmds; i++, j++) { + cmd = &msg->cmds[i]; + cmd_enable |= BIT(j); + cmd_complete |= cmd->wait << j; + msgid = cmd_msgid; + msgid |= cmd->wait ? CMD_MSGID_RESP_REQ : 0; + + write_tcs_cmd(drv, RSC_DRV_CMD_MSGID, tcs_id, j, msgid); + write_tcs_cmd(drv, RSC_DRV_CMD_ADDR, tcs_id, j, cmd->addr); + write_tcs_cmd(drv, RSC_DRV_CMD_DATA, tcs_id, j, cmd->data); + trace_rpmh_send_msg_rcuidle(drv, tcs_id, j, msgid, cmd); + } + + write_tcs_reg(drv, RSC_DRV_CMD_WAIT_FOR_CMPL, tcs_id, cmd_complete); + cmd_enable |= read_tcs_reg(drv, RSC_DRV_CMD_ENABLE, tcs_id); + write_tcs_reg(drv, RSC_DRV_CMD_ENABLE, tcs_id, cmd_enable); +} + +/** + * check_for_req_inflight() - Look to see if conflicting cmds are in flight. + * @drv: The controller. + * @tcs: A pointer to the tcs_group used for ACTIVE_ONLY transfers. + * @msg: The message we want to send, which will contain several addr/data + * pairs to program (but few enough that they all fit in one TCS). + * + * This will walk through the TCSes in the group and check if any of them + * appear to be sending to addresses referenced in the message. If it finds + * one it'll return -EBUSY. + * + * Only for use for active-only transfers. + * + * Must be called with the drv->lock held since that protects tcs_in_use. + * + * Return: 0 if nothing in flight or -EBUSY if we should try again later. + * The caller must re-enable interrupts between tries since that's + * the only way tcs_is_free() will ever return true and the only way + * RSC_DRV_CMD_ENABLE will ever be cleared. + */ +static int check_for_req_inflight(struct rsc_drv *drv, struct tcs_group *tcs, + const struct tcs_request *msg) +{ + unsigned long curr_enabled; + u32 addr; + int i, j, k; + int tcs_id = tcs->offset; + + for (i = 0; i < tcs->num_tcs; i++, tcs_id++) { + if (tcs_is_free(drv, tcs_id)) + continue; + + curr_enabled = read_tcs_reg(drv, RSC_DRV_CMD_ENABLE, tcs_id); + + for_each_set_bit(j, &curr_enabled, MAX_CMDS_PER_TCS) { + addr = read_tcs_cmd(drv, RSC_DRV_CMD_ADDR, tcs_id, j); + for (k = 0; k < msg->num_cmds; k++) { + if (addr == msg->cmds[k].addr) + return -EBUSY; + } + } + } + + return 0; +} + +/** + * find_free_tcs() - Find free tcs in the given tcs_group; only for active. + * @tcs: A pointer to the active-only tcs_group (or the wake tcs_group if + * we borrowed it because there are zero active-only ones). + * + * Must be called with the drv->lock held since that protects tcs_in_use. + * + * Return: The first tcs that's free. + */ +static int find_free_tcs(struct tcs_group *tcs) +{ + int i; + + for (i = 0; i < tcs->num_tcs; i++) { + if (tcs_is_free(tcs->drv, tcs->offset + i)) + return tcs->offset + i; + } + + return -EBUSY; +} + +/** + * claim_tcs_for_req() - Claim a tcs in the given tcs_group; only for active. + * @drv: The controller. + * @tcs: The tcs_group used for ACTIVE_ONLY transfers. + * @msg: The data to be sent. + * + * Claims a tcs in the given tcs_group while making sure that no existing cmd + * is in flight that would conflict with the one in @msg. + * + * Context: Must be called with the drv->lock held since that protects + * tcs_in_use. + * + * Return: The id of the claimed tcs or -EBUSY if a matching msg is in flight + * or the tcs_group is full. + */ +static int claim_tcs_for_req(struct rsc_drv *drv, struct tcs_group *tcs, + const struct tcs_request *msg) +{ + int ret; + + /* + * The h/w does not like if we send a request to the same address, + * when one is already in-flight or being processed. + */ + ret = check_for_req_inflight(drv, tcs, msg); + if (ret) + return ret; + + return find_free_tcs(tcs); +} + +/** + * rpmh_rsc_send_data() - Write / trigger active-only message. + * @drv: The controller. + * @msg: The data to be sent. + * + * NOTES: + * - This is only used for "ACTIVE_ONLY" since the limitations of this + * function don't make sense for sleep/wake cases. + * - To do the transfer, we will grab a whole TCS for ourselves--we don't + * try to share. If there are none available we'll wait indefinitely + * for a free one. + * - This function will not wait for the commands to be finished, only for + * data to be programmed into the RPMh. See rpmh_tx_done() which will + * be called when the transfer is fully complete. + * - This function must be called with interrupts enabled. If the hardware + * is busy doing someone else's transfer we need that transfer to fully + * finish so that we can have the hardware, and to fully finish it needs + * the interrupt handler to run. If the interrupts is set to run on the + * active CPU this can never happen if interrupts are disabled. + * + * Return: 0 on success, -EINVAL on error. + */ +int rpmh_rsc_send_data(struct rsc_drv *drv, const struct tcs_request *msg) +{ + struct tcs_group *tcs; + int tcs_id; + unsigned long flags; + + tcs = get_tcs_for_msg(drv, msg); + if (IS_ERR(tcs)) + return PTR_ERR(tcs); + + spin_lock_irqsave(&drv->lock, flags); + + /* Wait forever for a free tcs. It better be there eventually! */ + wait_event_lock_irq(drv->tcs_wait, + (tcs_id = claim_tcs_for_req(drv, tcs, msg)) >= 0, + drv->lock); + + tcs->req[tcs_id - tcs->offset] = msg; + set_bit(tcs_id, drv->tcs_in_use); + if (msg->state == RPMH_ACTIVE_ONLY_STATE && tcs->type != ACTIVE_TCS) { + /* + * Clear previously programmed WAKE commands in selected + * repurposed TCS to avoid triggering them. tcs->slots will be + * cleaned from rpmh_flush() by invoking rpmh_rsc_invalidate() + */ + write_tcs_reg_sync(drv, RSC_DRV_CMD_ENABLE, tcs_id, 0); + write_tcs_reg_sync(drv, RSC_DRV_CMD_WAIT_FOR_CMPL, tcs_id, 0); + enable_tcs_irq(drv, tcs_id, true); + } + spin_unlock_irqrestore(&drv->lock, flags); + + /* + * These two can be done after the lock is released because: + * - We marked "tcs_in_use" under lock. + * - Once "tcs_in_use" has been marked nobody else could be writing + * to these registers until the interrupt goes off. + * - The interrupt can't go off until we trigger w/ the last line + * of __tcs_set_trigger() below. + */ + __tcs_buffer_write(drv, tcs_id, 0, msg); + __tcs_set_trigger(drv, tcs_id, true); + + return 0; +} + +/** + * find_slots() - Find a place to write the given message. + * @tcs: The tcs group to search. + * @msg: The message we want to find room for. + * @tcs_id: If we return 0 from the function, we return the global ID of the + * TCS to write to here. + * @cmd_id: If we return 0 from the function, we return the index of + * the command array of the returned TCS where the client should + * start writing the message. + * + * Only for use on sleep/wake TCSes since those are the only ones we maintain + * tcs->slots for. + * + * Return: -ENOMEM if there was no room, else 0. + */ +static int find_slots(struct tcs_group *tcs, const struct tcs_request *msg, + int *tcs_id, int *cmd_id) +{ + int slot, offset; + int i = 0; + + /* Do over, until we can fit the full payload in a single TCS */ + do { + slot = bitmap_find_next_zero_area(tcs->slots, MAX_TCS_SLOTS, + i, msg->num_cmds, 0); + if (slot >= tcs->num_tcs * tcs->ncpt) + return -ENOMEM; + i += tcs->ncpt; + } while (slot + msg->num_cmds - 1 >= i); + + bitmap_set(tcs->slots, slot, msg->num_cmds); + + offset = slot / tcs->ncpt; + *tcs_id = offset + tcs->offset; + *cmd_id = slot % tcs->ncpt; + + return 0; +} + +/** + * rpmh_rsc_write_ctrl_data() - Write request to controller but don't trigger. + * @drv: The controller. + * @msg: The data to be written to the controller. + * + * This should only be called for for sleep/wake state, never active-only + * state. + * + * The caller must ensure that no other RPMH actions are happening and the + * controller is idle when this function is called since it runs lockless. + * + * Return: 0 if no error; else -error. + */ +int rpmh_rsc_write_ctrl_data(struct rsc_drv *drv, const struct tcs_request *msg) +{ + struct tcs_group *tcs; + int tcs_id = 0, cmd_id = 0; + int ret; + + tcs = get_tcs_for_msg(drv, msg); + if (IS_ERR(tcs)) + return PTR_ERR(tcs); + + /* find the TCS id and the command in the TCS to write to */ + ret = find_slots(tcs, msg, &tcs_id, &cmd_id); + if (!ret) + __tcs_buffer_write(drv, tcs_id, cmd_id, msg); + + return ret; +} + +/** + * rpmh_rsc_ctrlr_is_busy() - Check if any of the AMCs are busy. + * @drv: The controller + * + * Checks if any of the AMCs are busy in handling ACTIVE sets. + * This is called from the last cpu powering down before flushing + * SLEEP and WAKE sets. If AMCs are busy, controller can not enter + * power collapse, so deny from the last cpu's pm notification. + * + * Context: Must be called with the drv->lock held. + * + * Return: + * * False - AMCs are idle + * * True - AMCs are busy + */ +static bool rpmh_rsc_ctrlr_is_busy(struct rsc_drv *drv) +{ + int m; + struct tcs_group *tcs = &drv->tcs[ACTIVE_TCS]; + + /* + * If we made an active request on a RSC that does not have a + * dedicated TCS for active state use, then re-purposed wake TCSes + * should be checked for not busy, because we used wake TCSes for + * active requests in this case. + */ + if (!tcs->num_tcs) + tcs = &drv->tcs[WAKE_TCS]; + + for (m = tcs->offset; m < tcs->offset + tcs->num_tcs; m++) { + if (!tcs_is_free(drv, m)) + return true; + } + + return false; +} + +/** + * rpmh_rsc_cpu_pm_callback() - Check if any of the AMCs are busy. + * @nfb: Pointer to the notifier block in struct rsc_drv. + * @action: CPU_PM_ENTER, CPU_PM_ENTER_FAILED, or CPU_PM_EXIT. + * @v: Unused + * + * This function is given to cpu_pm_register_notifier so we can be informed + * about when CPUs go down. When all CPUs go down we know no more active + * transfers will be started so we write sleep/wake sets. This function gets + * called from cpuidle code paths and also at system suspend time. + * + * If its last CPU going down and AMCs are not busy then writes cached sleep + * and wake messages to TCSes. The firmware then takes care of triggering + * them when entering deepest low power modes. + * + * Return: See cpu_pm_register_notifier() + */ +static int rpmh_rsc_cpu_pm_callback(struct notifier_block *nfb, + unsigned long action, void *v) +{ + struct rsc_drv *drv = container_of(nfb, struct rsc_drv, rsc_pm); + int ret = NOTIFY_OK; + int cpus_in_pm; + + switch (action) { + case CPU_PM_ENTER: + cpus_in_pm = atomic_inc_return(&drv->cpus_in_pm); + /* + * NOTE: comments for num_online_cpus() point out that it's + * only a snapshot so we need to be careful. It should be OK + * for us to use, though. It's important for us not to miss + * if we're the last CPU going down so it would only be a + * problem if a CPU went offline right after we did the check + * AND that CPU was not idle AND that CPU was the last non-idle + * CPU. That can't happen. CPUs would have to come out of idle + * before the CPU could go offline. + */ + if (cpus_in_pm < num_online_cpus()) + return NOTIFY_OK; + break; + case CPU_PM_ENTER_FAILED: + case CPU_PM_EXIT: + atomic_dec(&drv->cpus_in_pm); + return NOTIFY_OK; + default: + return NOTIFY_DONE; + } + + /* + * It's likely we're on the last CPU. Grab the drv->lock and write + * out the sleep/wake commands to RPMH hardware. Grabbing the lock + * means that if we race with another CPU coming up we are still + * guaranteed to be safe. If another CPU came up just after we checked + * and has grabbed the lock or started an active transfer then we'll + * notice we're busy and abort. If another CPU comes up after we start + * flushing it will be blocked from starting an active transfer until + * we're done flushing. If another CPU starts an active transfer after + * we release the lock we're still OK because we're no longer the last + * CPU. + */ + if (spin_trylock(&drv->lock)) { + if (rpmh_rsc_ctrlr_is_busy(drv) || rpmh_flush(&drv->client)) + ret = NOTIFY_BAD; + spin_unlock(&drv->lock); + } else { + /* Another CPU must be up */ + return NOTIFY_OK; + } + + if (ret == NOTIFY_BAD) { + /* Double-check if we're here because someone else is up */ + if (cpus_in_pm < num_online_cpus()) + ret = NOTIFY_OK; + else + /* We won't be called w/ CPU_PM_ENTER_FAILED */ + atomic_dec(&drv->cpus_in_pm); + } + + return ret; +} + +static int rpmh_probe_tcs_config(struct platform_device *pdev, + struct rsc_drv *drv, void __iomem *base) +{ + struct tcs_type_config { + u32 type; + u32 n; + } tcs_cfg[TCS_TYPE_NR] = { { 0 } }; + struct device_node *dn = pdev->dev.of_node; + u32 config, max_tcs, ncpt, offset; + int i, ret, n, st = 0; + struct tcs_group *tcs; + + ret = of_property_read_u32(dn, "qcom,tcs-offset", &offset); + if (ret) + return ret; + drv->tcs_base = base + offset; + + config = readl_relaxed(base + DRV_PRNT_CHLD_CONFIG); + + max_tcs = config; + max_tcs &= DRV_NUM_TCS_MASK << (DRV_NUM_TCS_SHIFT * drv->id); + max_tcs = max_tcs >> (DRV_NUM_TCS_SHIFT * drv->id); + + ncpt = config & (DRV_NCPT_MASK << DRV_NCPT_SHIFT); + ncpt = ncpt >> DRV_NCPT_SHIFT; + + n = of_property_count_u32_elems(dn, "qcom,tcs-config"); + if (n != 2 * TCS_TYPE_NR) + return -EINVAL; + + for (i = 0; i < TCS_TYPE_NR; i++) { + ret = of_property_read_u32_index(dn, "qcom,tcs-config", + i * 2, &tcs_cfg[i].type); + if (ret) + return ret; + if (tcs_cfg[i].type >= TCS_TYPE_NR) + return -EINVAL; + + ret = of_property_read_u32_index(dn, "qcom,tcs-config", + i * 2 + 1, &tcs_cfg[i].n); + if (ret) + return ret; + if (tcs_cfg[i].n > MAX_TCS_PER_TYPE) + return -EINVAL; + } + + for (i = 0; i < TCS_TYPE_NR; i++) { + tcs = &drv->tcs[tcs_cfg[i].type]; + if (tcs->drv) + return -EINVAL; + tcs->drv = drv; + tcs->type = tcs_cfg[i].type; + tcs->num_tcs = tcs_cfg[i].n; + tcs->ncpt = ncpt; + + if (!tcs->num_tcs || tcs->type == CONTROL_TCS) + continue; + + if (st + tcs->num_tcs > max_tcs || + st + tcs->num_tcs >= BITS_PER_BYTE * sizeof(tcs->mask)) + return -EINVAL; + + tcs->mask = ((1 << tcs->num_tcs) - 1) << st; + tcs->offset = st; + st += tcs->num_tcs; + } + + drv->num_tcs = st; + + return 0; +} + +static int rpmh_rsc_probe(struct platform_device *pdev) +{ + struct device_node *dn = pdev->dev.of_node; + struct rsc_drv *drv; + struct resource *res; + char drv_id[10] = {0}; + int ret, irq; + u32 solver_config; + void __iomem *base; + + /* + * Even though RPMh doesn't directly use cmd-db, all of its children + * do. To avoid adding this check to our children we'll do it now. + */ + ret = cmd_db_ready(); + if (ret) { + if (ret != -EPROBE_DEFER) + dev_err(&pdev->dev, "Command DB not available (%d)\n", + ret); + return ret; + } + + drv = devm_kzalloc(&pdev->dev, sizeof(*drv), GFP_KERNEL); + if (!drv) + return -ENOMEM; + + ret = of_property_read_u32(dn, "qcom,drv-id", &drv->id); + if (ret) + return ret; + + drv->name = of_get_property(dn, "label", NULL); + if (!drv->name) + drv->name = dev_name(&pdev->dev); + + snprintf(drv_id, ARRAY_SIZE(drv_id), "drv-%d", drv->id); + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, drv_id); + base = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(base)) + return PTR_ERR(base); + + ret = rpmh_probe_tcs_config(pdev, drv, base); + if (ret) + return ret; + + spin_lock_init(&drv->lock); + init_waitqueue_head(&drv->tcs_wait); + bitmap_zero(drv->tcs_in_use, MAX_TCS_NR); + + irq = platform_get_irq(pdev, drv->id); + if (irq < 0) + return irq; + + ret = devm_request_irq(&pdev->dev, irq, tcs_tx_done, + IRQF_TRIGGER_HIGH | IRQF_NO_SUSPEND, + drv->name, drv); + if (ret) + return ret; + + /* + * CPU PM notification are not required for controllers that support + * 'HW solver' mode where they can be in autonomous mode executing low + * power mode to power down. + */ + solver_config = readl_relaxed(base + DRV_SOLVER_CONFIG); + solver_config &= DRV_HW_SOLVER_MASK << DRV_HW_SOLVER_SHIFT; + solver_config = solver_config >> DRV_HW_SOLVER_SHIFT; + if (!solver_config) { + drv->rsc_pm.notifier_call = rpmh_rsc_cpu_pm_callback; + cpu_pm_register_notifier(&drv->rsc_pm); + } + + /* Enable the active TCS to send requests immediately */ + writel_relaxed(drv->tcs[ACTIVE_TCS].mask, + drv->tcs_base + RSC_DRV_IRQ_ENABLE); + + spin_lock_init(&drv->client.cache_lock); + INIT_LIST_HEAD(&drv->client.cache); + INIT_LIST_HEAD(&drv->client.batch_cache); + + dev_set_drvdata(&pdev->dev, drv); + + return devm_of_platform_populate(&pdev->dev); +} + +static const struct of_device_id rpmh_drv_match[] = { + { .compatible = "qcom,rpmh-rsc", }, + { } +}; + +static struct platform_driver rpmh_driver = { + .probe = rpmh_rsc_probe, + .driver = { + .name = "rpmh", + .of_match_table = rpmh_drv_match, + .suppress_bind_attrs = true, + }, +}; + +static int __init rpmh_driver_init(void) +{ + return platform_driver_register(&rpmh_driver); +} +arch_initcall(rpmh_driver_init); |