/*
 * Copyright (C) 2016 Cavium, Inc.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of version 2 of the GNU General Public License
 * as published by the Free Software Foundation.
 */

#include <linux/device.h>
#include <linux/firmware.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/pci.h>
#include <linux/printk.h>
#include <linux/version.h>

#include "cptpf.h"

#define DRV_NAME        "thunder-cpt"
#define DRV_VERSION     "1.0"

static u32 num_vfs = 4; /* Default 4 VF enabled */
module_param(num_vfs, uint, 0444);
MODULE_PARM_DESC(num_vfs, "Number of VFs to enable(1-16)");

/*
 * Disable cores specified by coremask
 */
static void cpt_disable_cores(struct cpt_device *cpt, u64 coremask,
                              u8 type, u8 grp)
{
        u64 pf_exe_ctl;
        u32 timeout = 100;
        u64 grpmask = 0;
        struct device *dev = &cpt->pdev->dev;

        if (type == AE_TYPES)
                coremask = (coremask << cpt->max_se_cores);

        /* Disengage the cores from groups */
        grpmask = cpt_read_csr64(cpt->reg_base, CPTX_PF_GX_EN(0, grp));
        cpt_write_csr64(cpt->reg_base, CPTX_PF_GX_EN(0, grp),
                        (grpmask & ~coremask));
        udelay(CSR_DELAY);
        grp = cpt_read_csr64(cpt->reg_base, CPTX_PF_EXEC_BUSY(0));
        while (grp & coremask) {
                dev_err(dev, "Cores still busy %llx", coremask);
                grp = cpt_read_csr64(cpt->reg_base,
                                     CPTX_PF_EXEC_BUSY(0));
                if (timeout--)
                        break;

                udelay(CSR_DELAY);
        }

        /* Disable the cores */
        pf_exe_ctl = cpt_read_csr64(cpt->reg_base, CPTX_PF_EXE_CTL(0));
        cpt_write_csr64(cpt->reg_base, CPTX_PF_EXE_CTL(0),
                        (pf_exe_ctl & ~coremask));
        udelay(CSR_DELAY);
}

/*
 * Enable cores specified by coremask
 */
static void cpt_enable_cores(struct cpt_device *cpt, u64 coremask,
                             u8 type)
{
        u64 pf_exe_ctl;

        if (type == AE_TYPES)
                coremask = (coremask << cpt->max_se_cores);

        pf_exe_ctl = cpt_read_csr64(cpt->reg_base, CPTX_PF_EXE_CTL(0));
        cpt_write_csr64(cpt->reg_base, CPTX_PF_EXE_CTL(0),
                        (pf_exe_ctl | coremask));
        udelay(CSR_DELAY);
}

static void cpt_configure_group(struct cpt_device *cpt, u8 grp,
                                u64 coremask, u8 type)
{
        u64 pf_gx_en = 0;

        if (type == AE_TYPES)
                coremask = (coremask << cpt->max_se_cores);

        pf_gx_en = cpt_read_csr64(cpt->reg_base, CPTX_PF_GX_EN(0, grp));
        cpt_write_csr64(cpt->reg_base, CPTX_PF_GX_EN(0, grp),
                        (pf_gx_en | coremask));
        udelay(CSR_DELAY);
}

static void cpt_disable_mbox_interrupts(struct cpt_device *cpt)
{
        /* Clear mbox(0) interupts for all vfs */
        cpt_write_csr64(cpt->reg_base, CPTX_PF_MBOX_ENA_W1CX(0, 0), ~0ull);
}

static void cpt_disable_ecc_interrupts(struct cpt_device *cpt)
{
        /* Clear ecc(0) interupts for all vfs */
        cpt_write_csr64(cpt->reg_base, CPTX_PF_ECC0_ENA_W1C(0), ~0ull);
}

static void cpt_disable_exec_interrupts(struct cpt_device *cpt)
{
        /* Clear exec interupts for all vfs */
        cpt_write_csr64(cpt->reg_base, CPTX_PF_EXEC_ENA_W1C(0), ~0ull);
}

static void cpt_disable_all_interrupts(struct cpt_device *cpt)
{
        cpt_disable_mbox_interrupts(cpt);
        cpt_disable_ecc_interrupts(cpt);
        cpt_disable_exec_interrupts(cpt);
}

static void cpt_enable_mbox_interrupts(struct cpt_device *cpt)
{
        /* Set mbox(0) interupts for all vfs */
        cpt_write_csr64(cpt->reg_base, CPTX_PF_MBOX_ENA_W1SX(0, 0), ~0ull);
}

static int cpt_load_microcode(struct cpt_device *cpt, struct microcode *mcode)
{
        int ret = 0, core = 0, shift = 0;
        u32 total_cores = 0;
        struct device *dev = &cpt->pdev->dev;

        if (!mcode || !mcode->code) {
                dev_err(dev, "Either the mcode is null or data is NULL\n");
                return -EINVAL;
        }

        if (mcode->code_size == 0) {
                dev_err(dev, "microcode size is 0\n");
                return -EINVAL;
        }

        /* Assumes 0-9 are SE cores for UCODE_BASE registers and
         * AE core bases follow
         */
        if (mcode->is_ae) {
                core = CPT_MAX_SE_CORES; /* start couting from 10 */
                total_cores = CPT_MAX_TOTAL_CORES; /* upto 15 */
        } else {
                core = 0; /* start couting from 0 */
                total_cores = CPT_MAX_SE_CORES; /* upto 9 */
        }

        /* Point to microcode for each core of the group */
        for (; core < total_cores ; core++, shift++) {
                if (mcode->core_mask & (1 << shift)) {
                        cpt_write_csr64(cpt->reg_base,
                                        CPTX_PF_ENGX_UCODE_BASE(0, core),
                                        (u64)mcode->phys_base);
                }
        }
        return ret;
}

static int do_cpt_init(struct cpt_device *cpt, struct microcode *mcode)
{
        int ret = 0;
        struct device *dev = &cpt->pdev->dev;

        /* Make device not ready */
        cpt->flags &= ~CPT_FLAG_DEVICE_READY;
        /* Disable All PF interrupts */
        cpt_disable_all_interrupts(cpt);
        /* Calculate mcode group and coremasks */
        if (mcode->is_ae) {
                if (mcode->num_cores > cpt->max_ae_cores) {
                        dev_err(dev, "Requested for more cores than available AE cores\n");
                        ret = -EINVAL;
                        goto cpt_init_fail;
                }

                if (cpt->next_group >= CPT_MAX_CORE_GROUPS) {
                        dev_err(dev, "Can't load, all eight microcode groups in use");
                        return -ENFILE;
                }

                mcode->group = cpt->next_group;
                /* Convert requested cores to mask */
                mcode->core_mask = GENMASK(mcode->num_cores, 0);
                cpt_disable_cores(cpt, mcode->core_mask, AE_TYPES,
                                  mcode->group);
                /* Load microcode for AE engines */
                ret = cpt_load_microcode(cpt, mcode);
                if (ret) {
                        dev_err(dev, "Microcode load Failed for %s\n",
                                mcode->version);
                        goto cpt_init_fail;
                }
                cpt->next_group++;
                /* Configure group mask for the mcode */
                cpt_configure_group(cpt, mcode->group, mcode->core_mask,
                                    AE_TYPES);
                /* Enable AE cores for the group mask */
                cpt_enable_cores(cpt, mcode->core_mask, AE_TYPES);
        } else {
                if (mcode->num_cores > cpt->max_se_cores) {
                        dev_err(dev, "Requested for more cores than available SE cores\n");
                        ret = -EINVAL;
                        goto cpt_init_fail;
                }
                if (cpt->next_group >= CPT_MAX_CORE_GROUPS) {
                        dev_err(dev, "Can't load, all eight microcode groups in use");
                        return -ENFILE;
                }

                mcode->group = cpt->next_group;
                /* Covert requested cores to mask */
                mcode->core_mask = GENMASK(mcode->num_cores, 0);
                cpt_disable_cores(cpt, mcode->core_mask, SE_TYPES,
                                  mcode->group);
                /* Load microcode for SE engines */
                ret = cpt_load_microcode(cpt, mcode);
                if (ret) {
                        dev_err(dev, "Microcode load Failed for %s\n",
                                mcode->version);
                        goto cpt_init_fail;
                }
                cpt->next_group++;
                /* Configure group mask for the mcode */
                cpt_configure_group(cpt, mcode->group, mcode->core_mask,
                                    SE_TYPES);
                /* Enable SE cores for the group mask */
                cpt_enable_cores(cpt, mcode->core_mask, SE_TYPES);
        }

        /* Enabled PF mailbox interrupts */
        cpt_enable_mbox_interrupts(cpt);
        cpt->flags |= CPT_FLAG_DEVICE_READY;

        return ret;

cpt_init_fail:
        /* Enabled PF mailbox interrupts */
        cpt_enable_mbox_interrupts(cpt);

        return ret;
}

struct ucode_header {
        u8 version[CPT_UCODE_VERSION_SZ];
        u32 code_length;
        u32 data_length;
        u64 sram_address;
};

static int cpt_ucode_load_fw(struct cpt_device *cpt, const u8 *fw, bool is_ae)
{
        const struct firmware *fw_entry;
        struct device *dev = &cpt->pdev->dev;
        struct ucode_header *ucode;
        struct microcode *mcode;
        int j, ret = 0;

        ret = request_firmware(&fw_entry, fw, dev);
        if (ret)
                return ret;

        ucode = (struct ucode_header *)fw_entry->data;
        mcode = &cpt->mcode[cpt->next_mc_idx];
        memcpy(mcode->version, (u8 *)fw_entry->data, CPT_UCODE_VERSION_SZ);
        mcode->code_size = ntohl(ucode->code_length) * 2;
        if (!mcode->code_size) {
                ret = -EINVAL;
                goto fw_release;
        }

        mcode->is_ae = is_ae;
        mcode->core_mask = 0ULL;
        mcode->num_cores = is_ae ? 6 : 10;

        /*  Allocate DMAable space */
        mcode->code = dma_zalloc_coherent(&cpt->pdev->dev, mcode->code_size,
                                          &mcode->phys_base, GFP_KERNEL);
        if (!mcode->code) {
                dev_err(dev, "Unable to allocate space for microcode");
                ret = -ENOMEM;
                goto fw_release;
        }

        memcpy((void *)mcode->code, (void *)(fw_entry->data + sizeof(*ucode)),
               mcode->code_size);

        /* Byte swap 64-bit */
        for (j = 0; j < (mcode->code_size / 8); j++)
                ((u64 *)mcode->code)[j] = cpu_to_be64(((u64 *)mcode->code)[j]);
        /*  MC needs 16-bit swap */
        for (j = 0; j < (mcode->code_size / 2); j++)
                ((u16 *)mcode->code)[j] = cpu_to_be16(((u16 *)mcode->code)[j]);

        dev_dbg(dev, "mcode->code_size = %u\n", mcode->code_size);
        dev_dbg(dev, "mcode->is_ae = %u\n", mcode->is_ae);
        dev_dbg(dev, "mcode->num_cores = %u\n", mcode->num_cores);
        dev_dbg(dev, "mcode->code = %llx\n", (u64)mcode->code);
        dev_dbg(dev, "mcode->phys_base = %llx\n", mcode->phys_base);

        ret = do_cpt_init(cpt, mcode);
        if (ret) {
                dev_err(dev, "do_cpt_init failed with ret: %d\n", ret);
                goto fw_release;
        }

        dev_info(dev, "Microcode Loaded %s\n", mcode->version);
        mcode->is_mc_valid = 1;
        cpt->next_mc_idx++;

fw_release:
        release_firmware(fw_entry);

        return ret;
}

static int cpt_ucode_load(struct cpt_device *cpt)
{
        int ret = 0;
        struct device *dev = &cpt->pdev->dev;

        ret = cpt_ucode_load_fw(cpt, "cpt8x-mc-ae.out", true);
        if (ret) {
                dev_err(dev, "ae:cpt_ucode_load failed with ret: %d\n", ret);
                return ret;
        }
        ret = cpt_ucode_load_fw(cpt, "cpt8x-mc-se.out", false);
        if (ret) {
                dev_err(dev, "se:cpt_ucode_load failed with ret: %d\n", ret);
                return ret;
        }

        return ret;
}

static irqreturn_t cpt_mbx0_intr_handler(int irq, void *cpt_irq)
{
        struct cpt_device *cpt = (struct cpt_device *)cpt_irq;

        cpt_mbox_intr_handler(cpt, 0);

        return IRQ_HANDLED;
}

static void cpt_reset(struct cpt_device *cpt)
{
        cpt_write_csr64(cpt->reg_base, CPTX_PF_RESET(0), 1);
}

static void cpt_find_max_enabled_cores(struct cpt_device *cpt)
{
        union cptx_pf_constants pf_cnsts = {0};

        pf_cnsts.u = cpt_read_csr64(cpt->reg_base, CPTX_PF_CONSTANTS(0));
        cpt->max_se_cores = pf_cnsts.s.se;
        cpt->max_ae_cores = pf_cnsts.s.ae;
}

static u32 cpt_check_bist_status(struct cpt_device *cpt)
{
        union cptx_pf_bist_status bist_sts = {0};

        bist_sts.u = cpt_read_csr64(cpt->reg_base,
                                    CPTX_PF_BIST_STATUS(0));

        return bist_sts.u;
}

static u64 cpt_check_exe_bist_status(struct cpt_device *cpt)
{
        union cptx_pf_exe_bist_status bist_sts = {0};

        bist_sts.u = cpt_read_csr64(cpt->reg_base,
                                    CPTX_PF_EXE_BIST_STATUS(0));

        return bist_sts.u;
}

static void cpt_disable_all_cores(struct cpt_device *cpt)
{
        u32 grp, timeout = 100;
        struct device *dev = &cpt->pdev->dev;

        /* Disengage the cores from groups */
        for (grp = 0; grp < CPT_MAX_CORE_GROUPS; grp++) {
                cpt_write_csr64(cpt->reg_base, CPTX_PF_GX_EN(0, grp), 0);
                udelay(CSR_DELAY);
        }

        grp = cpt_read_csr64(cpt->reg_base, CPTX_PF_EXEC_BUSY(0));
        while (grp) {
                dev_err(dev, "Cores still busy");
                grp = cpt_read_csr64(cpt->reg_base,
                                     CPTX_PF_EXEC_BUSY(0));
                if (timeout--)
                        break;

                udelay(CSR_DELAY);
        }
        /* Disable the cores */
        cpt_write_csr64(cpt->reg_base, CPTX_PF_EXE_CTL(0), 0);
}

/**
 * Ensure all cores are disengaged from all groups by
 * calling cpt_disable_all_cores() before calling this
 * function.
 */
static void cpt_unload_microcode(struct cpt_device *cpt)
{
        u32 grp = 0, core;

        /* Free microcode bases and reset group masks */
        for (grp = 0; grp < CPT_MAX_CORE_GROUPS; grp++) {
                struct microcode *mcode = &cpt->mcode[grp];

                if (cpt->mcode[grp].code)
                        dma_free_coherent(&cpt->pdev->dev, mcode->code_size,
                                          mcode->code, mcode->phys_base);
                mcode->code = NULL;
        }
        /* Clear UCODE_BASE registers for all engines */
        for (core = 0; core < CPT_MAX_TOTAL_CORES; core++)
                cpt_write_csr64(cpt->reg_base,
                                CPTX_PF_ENGX_UCODE_BASE(0, core), 0ull);
}

static int cpt_device_init(struct cpt_device *cpt)
{
        u64 bist;
        struct device *dev = &cpt->pdev->dev;

        /* Reset the PF when probed first */
        cpt_reset(cpt);
        mdelay(100);

        /*Check BIST status*/
        bist = (u64)cpt_check_bist_status(cpt);
        if (bist) {
                dev_err(dev, "RAM BIST failed with code 0x%llx", bist);
                return -ENODEV;
        }

        bist = cpt_check_exe_bist_status(cpt);
        if (bist) {
                dev_err(dev, "Engine BIST failed with code 0x%llx", bist);
                return -ENODEV;
        }

        /*Get CLK frequency*/
        /*Get max enabled cores */
        cpt_find_max_enabled_cores(cpt);
        /*Disable all cores*/
        cpt_disable_all_cores(cpt);
        /*Reset device parameters*/
        cpt->next_mc_idx   = 0;
        cpt->next_group = 0;
        /* PF is ready */
        cpt->flags |= CPT_FLAG_DEVICE_READY;

        return 0;
}

static int cpt_register_interrupts(struct cpt_device *cpt)
{
        int ret;
        struct device *dev = &cpt->pdev->dev;

        /* Enable MSI-X */
        ret = pci_alloc_irq_vectors(cpt->pdev, CPT_PF_MSIX_VECTORS,
                        CPT_PF_MSIX_VECTORS, PCI_IRQ_MSIX);
        if (ret < 0) {
                dev_err(&cpt->pdev->dev, "Request for #%d msix vectors failed\n",
                        CPT_PF_MSIX_VECTORS);
                return ret;
        }

        /* Register mailbox interrupt handlers */
        ret = request_irq(pci_irq_vector(cpt->pdev, CPT_PF_INT_VEC_E_MBOXX(0)),
                          cpt_mbx0_intr_handler, 0, "CPT Mbox0", cpt);
        if (ret)
                goto fail;

        /* Enable mailbox interrupt */
        cpt_enable_mbox_interrupts(cpt);
        return 0;

fail:
        dev_err(dev, "Request irq failed\n");
        pci_disable_msix(cpt->pdev);
        return ret;
}

static void cpt_unregister_interrupts(struct cpt_device *cpt)
{
        free_irq(pci_irq_vector(cpt->pdev, CPT_PF_INT_VEC_E_MBOXX(0)), cpt);
        pci_disable_msix(cpt->pdev);
}

static int cpt_sriov_init(struct cpt_device *cpt, int num_vfs)
{
        int pos = 0;
        int err;
        u16 total_vf_cnt;
        struct pci_dev *pdev = cpt->pdev;

        pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_SRIOV);
        if (!pos) {
                dev_err(&pdev->dev, "SRIOV capability is not found in PCIe config space\n");
                return -ENODEV;
        }

        cpt->num_vf_en = num_vfs; /* User requested VFs */
        pci_read_config_word(pdev, (pos + PCI_SRIOV_TOTAL_VF), &total_vf_cnt);
        if (total_vf_cnt < cpt->num_vf_en)
                cpt->num_vf_en = total_vf_cnt;

        if (!total_vf_cnt)
                return 0;

        /*Enabled the available VFs */
        err = pci_enable_sriov(pdev, cpt->num_vf_en);
        if (err) {
                dev_err(&pdev->dev, "SRIOV enable failed, num VF is %d\n",
                        cpt->num_vf_en);
                cpt->num_vf_en = 0;
                return err;
        }

        /* TODO: Optionally enable static VQ priorities feature */

        dev_info(&pdev->dev, "SRIOV enabled, number of VF available %d\n",
                 cpt->num_vf_en);

        cpt->flags |= CPT_FLAG_SRIOV_ENABLED;

        return 0;
}

static int cpt_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
{
        struct device *dev = &pdev->dev;
        struct cpt_device *cpt;
        int err;

        if (num_vfs > 16 || num_vfs < 4) {
                dev_warn(dev, "Invalid vf count %d, Resetting it to 4(default)\n",
                         num_vfs);
                num_vfs = 4;
        }

        cpt = devm_kzalloc(dev, sizeof(*cpt), GFP_KERNEL);
        if (!cpt)
                return -ENOMEM;

        pci_set_drvdata(pdev, cpt);
        cpt->pdev = pdev;
        err = pci_enable_device(pdev);
        if (err) {
                dev_err(dev, "Failed to enable PCI device\n");
                pci_set_drvdata(pdev, NULL);
                return err;
        }

        err = pci_request_regions(pdev, DRV_NAME);
        if (err) {
                dev_err(dev, "PCI request regions failed 0x%x\n", err);
                goto cpt_err_disable_device;
        }

        err = pci_set_dma_mask(pdev, DMA_BIT_MASK(48));
        if (err) {
                dev_err(dev, "Unable to get usable DMA configuration\n");
                goto cpt_err_release_regions;
        }

        err = pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(48));
        if (err) {
                dev_err(dev, "Unable to get 48-bit DMA for consistent allocations\n");
                goto cpt_err_release_regions;
        }

        /* MAP PF's configuration registers */
        cpt->reg_base = pcim_iomap(pdev, 0, 0);
        if (!cpt->reg_base) {
                dev_err(dev, "Cannot map config register space, aborting\n");
                err = -ENOMEM;
                goto cpt_err_release_regions;
        }

        /* CPT device HW initialization */
        cpt_device_init(cpt);

        /* Register interrupts */
        err = cpt_register_interrupts(cpt);
        if (err)
                goto cpt_err_release_regions;

        err = cpt_ucode_load(cpt);
        if (err)
                goto cpt_err_unregister_interrupts;

        /* Configure SRIOV */
        err = cpt_sriov_init(cpt, num_vfs);
        if (err)
                goto cpt_err_unregister_interrupts;

        return 0;

cpt_err_unregister_interrupts:
        cpt_unregister_interrupts(cpt);
cpt_err_release_regions:
        pci_release_regions(pdev);
cpt_err_disable_device:
        pci_disable_device(pdev);
        pci_set_drvdata(pdev, NULL);
        return err;
}

static void cpt_remove(struct pci_dev *pdev)
{
        struct cpt_device *cpt = pci_get_drvdata(pdev);

        /* Disengage SE and AE cores from all groups*/
        cpt_disable_all_cores(cpt);
        /* Unload microcodes */
        cpt_unload_microcode(cpt);
        cpt_unregister_interrupts(cpt);
        pci_disable_sriov(pdev);
        pci_release_regions(pdev);
        pci_disable_device(pdev);
        pci_set_drvdata(pdev, NULL);
}

static void cpt_shutdown(struct pci_dev *pdev)
{
        struct cpt_device *cpt = pci_get_drvdata(pdev);

        if (!cpt)
                return;

        dev_info(&pdev->dev, "Shutdown device %x:%x.\n",
                 (u32)pdev->vendor, (u32)pdev->device);

        cpt_unregister_interrupts(cpt);
        pci_release_regions(pdev);
        pci_disable_device(pdev);
        pci_set_drvdata(pdev, NULL);
}

/* Supported devices */
static const struct pci_device_id cpt_id_table[] = {
        { PCI_DEVICE(PCI_VENDOR_ID_CAVIUM, CPT_81XX_PCI_PF_DEVICE_ID) },
        { 0, }  /* end of table */
};

static struct pci_driver cpt_pci_driver = {
        .name = DRV_NAME,
        .id_table = cpt_id_table,
        .probe = cpt_probe,
        .remove = cpt_remove,
        .shutdown = cpt_shutdown,
};

module_pci_driver(cpt_pci_driver);

MODULE_AUTHOR("George Cherian <george.cherian@cavium.com>");
MODULE_DESCRIPTION("Cavium Thunder CPT Physical Function Driver");
MODULE_LICENSE("GPL v2");
MODULE_VERSION(DRV_VERSION);
MODULE_DEVICE_TABLE(pci, cpt_id_table);