From 119e9db233ad0f4cbd4cfb9f9385a7bca378b37d Mon Sep 17 00:00:00 2001 From: Zeng Chi Date: Mon, 21 Sep 2026 18:24:42 +0800 Subject: KVM: Don't pre-reserve xarray entries when storing empty/NULL attributes Skip the xarray reservation loop when clearing all memory attributes, as storing NULL only erases the entry and never needs to allocate, so no reservation (and no cleanup of a failed one) is required in that case. Suggested-by: Sean Christopherson Cc: David Ballesteros Signed-off-by: Zeng Chi Link: https://patch.msgid.link/20260921102442.1232375-1-zeng_chi911@163.com [sean: split to separate patch] Signed-off-by: Sean Christopherson --- drivers/mailbox/pl320-ipc.c | 175 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 175 insertions(+) create mode 100644 drivers/mailbox/pl320-ipc.c (limited to 'drivers/mailbox/pl320-ipc.c') diff --git a/drivers/mailbox/pl320-ipc.c b/drivers/mailbox/pl320-ipc.c new file mode 100644 index 000000000..606f26a2a --- /dev/null +++ b/drivers/mailbox/pl320-ipc.c @@ -0,0 +1,175 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright 2012 Calxeda, Inc. + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include + +#define IPCMxSOURCE(m) ((m) * 0x40) +#define IPCMxDSET(m) (((m) * 0x40) + 0x004) +#define IPCMxDCLEAR(m) (((m) * 0x40) + 0x008) +#define IPCMxDSTATUS(m) (((m) * 0x40) + 0x00C) +#define IPCMxMODE(m) (((m) * 0x40) + 0x010) +#define IPCMxMSET(m) (((m) * 0x40) + 0x014) +#define IPCMxMCLEAR(m) (((m) * 0x40) + 0x018) +#define IPCMxMSTATUS(m) (((m) * 0x40) + 0x01C) +#define IPCMxSEND(m) (((m) * 0x40) + 0x020) +#define IPCMxDR(m, dr) (((m) * 0x40) + ((dr) * 4) + 0x024) + +#define IPCMMIS(irq) (((irq) * 8) + 0x800) +#define IPCMRIS(irq) (((irq) * 8) + 0x804) + +#define MBOX_MASK(n) (1 << (n)) +#define IPC_TX_MBOX 1 +#define IPC_RX_MBOX 2 + +#define CHAN_MASK(n) (1 << (n)) +#define A9_SOURCE 1 +#define M3_SOURCE 0 + +static void __iomem *ipc_base; +static int ipc_irq; +static DEFINE_MUTEX(ipc_m1_lock); +static DECLARE_COMPLETION(ipc_completion); +static ATOMIC_NOTIFIER_HEAD(ipc_notifier); + +static void __ipc_send(int mbox, u32 *data) +{ + int i; + for (i = 0; i < 7; i++) + writel_relaxed(data[i], ipc_base + IPCMxDR(mbox, i)); + writel_relaxed(0x1, ipc_base + IPCMxSEND(mbox)); +} + +static u32 __ipc_rcv(int mbox, u32 *data) +{ + int i; + for (i = 0; i < 7; i++) + data[i] = readl_relaxed(ipc_base + IPCMxDR(mbox, i)); + return data[1]; +} + +/* blocking implementation from the A9 side, not usable in interrupts! */ +int pl320_ipc_transmit(u32 *data) +{ + int ret; + + mutex_lock(&ipc_m1_lock); + + init_completion(&ipc_completion); + __ipc_send(IPC_TX_MBOX, data); + ret = wait_for_completion_timeout(&ipc_completion, + msecs_to_jiffies(1000)); + if (ret == 0) { + ret = -ETIMEDOUT; + goto out; + } + + ret = __ipc_rcv(IPC_TX_MBOX, data); +out: + mutex_unlock(&ipc_m1_lock); + return ret; +} +EXPORT_SYMBOL_GPL(pl320_ipc_transmit); + +static irqreturn_t ipc_handler(int irq, void *dev) +{ + u32 irq_stat; + u32 data[7]; + + irq_stat = readl_relaxed(ipc_base + IPCMMIS(1)); + if (irq_stat & MBOX_MASK(IPC_TX_MBOX)) { + writel_relaxed(0, ipc_base + IPCMxSEND(IPC_TX_MBOX)); + complete(&ipc_completion); + } + if (irq_stat & MBOX_MASK(IPC_RX_MBOX)) { + __ipc_rcv(IPC_RX_MBOX, data); + atomic_notifier_call_chain(&ipc_notifier, data[0], data + 1); + writel_relaxed(2, ipc_base + IPCMxSEND(IPC_RX_MBOX)); + } + + return IRQ_HANDLED; +} + +int pl320_ipc_register_notifier(struct notifier_block *nb) +{ + return atomic_notifier_chain_register(&ipc_notifier, nb); +} +EXPORT_SYMBOL_GPL(pl320_ipc_register_notifier); + +int pl320_ipc_unregister_notifier(struct notifier_block *nb) +{ + return atomic_notifier_chain_unregister(&ipc_notifier, nb); +} +EXPORT_SYMBOL_GPL(pl320_ipc_unregister_notifier); + +static int pl320_probe(struct amba_device *adev, const struct amba_id *id) +{ + int ret; + + ipc_base = ioremap(adev->res.start, resource_size(&adev->res)); + if (ipc_base == NULL) + return -ENOMEM; + + writel_relaxed(0, ipc_base + IPCMxSEND(IPC_TX_MBOX)); + + ipc_irq = adev->irq[0]; + ret = request_irq(ipc_irq, ipc_handler, 0, dev_name(&adev->dev), NULL); + if (ret < 0) + goto err; + + /* Init slow mailbox */ + writel_relaxed(CHAN_MASK(A9_SOURCE), + ipc_base + IPCMxSOURCE(IPC_TX_MBOX)); + writel_relaxed(CHAN_MASK(M3_SOURCE), + ipc_base + IPCMxDSET(IPC_TX_MBOX)); + writel_relaxed(CHAN_MASK(M3_SOURCE) | CHAN_MASK(A9_SOURCE), + ipc_base + IPCMxMSET(IPC_TX_MBOX)); + + /* Init receive mailbox */ + writel_relaxed(CHAN_MASK(M3_SOURCE), + ipc_base + IPCMxSOURCE(IPC_RX_MBOX)); + writel_relaxed(CHAN_MASK(A9_SOURCE), + ipc_base + IPCMxDSET(IPC_RX_MBOX)); + writel_relaxed(CHAN_MASK(M3_SOURCE) | CHAN_MASK(A9_SOURCE), + ipc_base + IPCMxMSET(IPC_RX_MBOX)); + + return 0; +err: + iounmap(ipc_base); + return ret; +} + +static const struct amba_id pl320_ids[] = { + { + .id = 0x00041320, + .mask = 0x000fffff, + }, + { 0, 0 }, +}; + +static struct amba_driver pl320_driver = { + .drv = { + .name = "pl320", + }, + .id_table = pl320_ids, + .probe = pl320_probe, +}; + +static int __init ipc_init(void) +{ + return amba_driver_register(&pl320_driver); +} +subsys_initcall(ipc_init); -- cgit v1.3.1