/*
 * Copyright 2012 Advanced Micro Devices, Inc.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 *
 */

#include <linux/pci.h>

#include "amdgpu.h"
#include "amdgpu_ih.h"
#include "cikd.h"

#include "bif/bif_4_1_d.h"
#include "bif/bif_4_1_sh_mask.h"

#include "oss/oss_2_0_d.h"
#include "oss/oss_2_0_sh_mask.h"

/*
 * Interrupts
 * Starting with r6xx, interrupts are handled via a ring buffer.
 * Ring buffers are areas of GPU accessible memory that the GPU
 * writes interrupt vectors into and the host reads vectors out of.
 * There is a rptr (read pointer) that determines where the
 * host is currently reading, and a wptr (write pointer)
 * which determines where the GPU has written.  When the
 * pointers are equal, the ring is idle.  When the GPU
 * writes vectors to the ring buffer, it increments the
 * wptr.  When there is an interrupt, the host then starts
 * fetching commands and processing them until the pointers are
 * equal again at which point it updates the rptr.
 */

static void cik_ih_set_interrupt_funcs(struct amdgpu_device *adev);

/**
 * cik_ih_enable_interrupts - Enable the interrupt ring buffer
 *
 * @adev: amdgpu_device pointer
 *
 * Enable the interrupt ring buffer (CIK).
 */
static void cik_ih_enable_interrupts(struct amdgpu_device *adev)
{
        u32 ih_cntl = RREG32(mmIH_CNTL);
        u32 ih_rb_cntl = RREG32(mmIH_RB_CNTL);

        ih_cntl |= IH_CNTL__ENABLE_INTR_MASK;
        ih_rb_cntl |= IH_RB_CNTL__RB_ENABLE_MASK;
        WREG32(mmIH_CNTL, ih_cntl);
        WREG32(mmIH_RB_CNTL, ih_rb_cntl);
        adev->irq.ih.enabled = true;
}

/**
 * cik_ih_disable_interrupts - Disable the interrupt ring buffer
 *
 * @adev: amdgpu_device pointer
 *
 * Disable the interrupt ring buffer (CIK).
 */
static void cik_ih_disable_interrupts(struct amdgpu_device *adev)
{
        u32 ih_rb_cntl = RREG32(mmIH_RB_CNTL);
        u32 ih_cntl = RREG32(mmIH_CNTL);

        ih_rb_cntl &= ~IH_RB_CNTL__RB_ENABLE_MASK;
        ih_cntl &= ~IH_CNTL__ENABLE_INTR_MASK;
        WREG32(mmIH_RB_CNTL, ih_rb_cntl);
        WREG32(mmIH_CNTL, ih_cntl);
        /* set rptr, wptr to 0 */
        WREG32(mmIH_RB_RPTR, 0);
        WREG32(mmIH_RB_WPTR, 0);
        adev->irq.ih.enabled = false;
        adev->irq.ih.rptr = 0;
}

/**
 * cik_ih_irq_init - init and enable the interrupt ring
 *
 * @adev: amdgpu_device pointer
 *
 * Allocate a ring buffer for the interrupt controller,
 * enable the RLC, disable interrupts, enable the IH
 * ring buffer and enable it (CIK).
 * Called at device load and reume.
 * Returns 0 for success, errors for failure.
 */
static int cik_ih_irq_init(struct amdgpu_device *adev)
{
        struct amdgpu_ih_ring *ih = &adev->irq.ih;
        int rb_bufsz;
        u32 interrupt_cntl, ih_cntl, ih_rb_cntl;

        /* disable irqs */
        cik_ih_disable_interrupts(adev);

        /* setup interrupt control */
        WREG32(mmINTERRUPT_CNTL2, adev->dummy_page_addr >> 8);
        interrupt_cntl = RREG32(mmINTERRUPT_CNTL);
        /* INTERRUPT_CNTL__IH_DUMMY_RD_OVERRIDE_MASK=0 - dummy read disabled with msi, enabled without msi
         * INTERRUPT_CNTL__IH_DUMMY_RD_OVERRIDE_MASK=1 - dummy read controlled by IH_DUMMY_RD_EN
         */
        interrupt_cntl &= ~INTERRUPT_CNTL__IH_DUMMY_RD_OVERRIDE_MASK;
        /* INTERRUPT_CNTL__IH_REQ_NONSNOOP_EN_MASK=1 if ring is in non-cacheable memory, e.g., vram */
        interrupt_cntl &= ~INTERRUPT_CNTL__IH_REQ_NONSNOOP_EN_MASK;
        WREG32(mmINTERRUPT_CNTL, interrupt_cntl);

        WREG32(mmIH_RB_BASE, adev->irq.ih.gpu_addr >> 8);
        rb_bufsz = order_base_2(adev->irq.ih.ring_size / 4);

        ih_rb_cntl = (IH_RB_CNTL__WPTR_OVERFLOW_ENABLE_MASK |
                      IH_RB_CNTL__WPTR_OVERFLOW_CLEAR_MASK |
                      (rb_bufsz << 1));

        ih_rb_cntl |= IH_RB_CNTL__WPTR_WRITEBACK_ENABLE_MASK;

        /* set the writeback address whether it's enabled or not */
        WREG32(mmIH_RB_WPTR_ADDR_LO, lower_32_bits(ih->wptr_addr));
        WREG32(mmIH_RB_WPTR_ADDR_HI, upper_32_bits(ih->wptr_addr) & 0xFF);

        WREG32(mmIH_RB_CNTL, ih_rb_cntl);

        /* set rptr, wptr to 0 */
        WREG32(mmIH_RB_RPTR, 0);
        WREG32(mmIH_RB_WPTR, 0);

        /* Default settings for IH_CNTL (disabled at first) */
        ih_cntl = (0x10 << IH_CNTL__MC_WRREQ_CREDIT__SHIFT) |
                (0x10 << IH_CNTL__MC_WR_CLEAN_CNT__SHIFT) |
                (0 << IH_CNTL__MC_VMID__SHIFT);
        /* IH_CNTL__RPTR_REARM_MASK only works if msi's are enabled */
        if (adev->irq.msi_enabled)
                ih_cntl |= IH_CNTL__RPTR_REARM_MASK;
        WREG32(mmIH_CNTL, ih_cntl);

        pci_set_master(adev->pdev);

        /* enable irqs */
        cik_ih_enable_interrupts(adev);

        if (adev->irq.ih_soft.ring_size)
                adev->irq.ih_soft.enabled = true;

        return 0;
}

/**
 * cik_ih_irq_disable - disable interrupts
 *
 * @adev: amdgpu_device pointer
 *
 * Disable interrupts on the hw (CIK).
 */
static void cik_ih_irq_disable(struct amdgpu_device *adev)
{
        cik_ih_disable_interrupts(adev);
        /* Wait and acknowledge irq */
        mdelay(1);
}

/**
 * cik_ih_get_wptr - get the IH ring buffer wptr
 *
 * @adev: amdgpu_device pointer
 * @ih: IH ring buffer to fetch wptr
 *
 * Get the IH ring buffer wptr from either the register
 * or the writeback memory buffer (CIK).  Also check for
 * ring buffer overflow and deal with it.
 * Used by cik_irq_process().
 * Returns the value of the wptr.
 */
static u32 cik_ih_get_wptr(struct amdgpu_device *adev,
                           struct amdgpu_ih_ring *ih)
{
        u32 wptr, tmp;

        wptr = le32_to_cpu(*ih->wptr_cpu);

        if (ih == &adev->irq.ih_soft)
                goto out;

        if (wptr & IH_RB_WPTR__RB_OVERFLOW_MASK) {
                wptr &= ~IH_RB_WPTR__RB_OVERFLOW_MASK;
                /* When a ring buffer overflow happen start parsing interrupt
                 * from the last not overwritten vector (wptr + 16). Hopefully
                 * this should allow us to catchup.
                 */
                dev_warn(adev->dev, "IH ring buffer overflow (0x%08X, 0x%08X, 0x%08X)\n",
                         wptr, ih->rptr, (wptr + 16) & ih->ptr_mask);
                ih->rptr = (wptr + 16) & ih->ptr_mask;
                tmp = RREG32(mmIH_RB_CNTL);
                tmp |= IH_RB_CNTL__WPTR_OVERFLOW_CLEAR_MASK;
                WREG32(mmIH_RB_CNTL, tmp);

                /* Unset the CLEAR_OVERFLOW bit immediately so new overflows
                 * can be detected.
                 */
                tmp &= ~IH_RB_CNTL__WPTR_OVERFLOW_CLEAR_MASK;
                WREG32(mmIH_RB_CNTL, tmp);
        }

out:
        return (wptr & ih->ptr_mask);
}

/*        CIK IV Ring
 * Each IV ring entry is 128 bits:
 * [7:0]    - interrupt source id
 * [31:8]   - reserved
 * [59:32]  - interrupt source data
 * [63:60]  - reserved
 * [71:64]  - RINGID
 *            CP:
 *            ME_ID [1:0], PIPE_ID[1:0], QUEUE_ID[2:0]
 *            QUEUE_ID - for compute, which of the 8 queues owned by the dispatcher
 *                     - for gfx, hw shader state (0=PS...5=LS, 6=CS)
 *            ME_ID - 0 = gfx, 1 = first 4 CS pipes, 2 = second 4 CS pipes
 *            PIPE_ID - ME0 0=3D
 *                    - ME1&2 compute dispatcher (4 pipes each)
 *            SDMA:
 *            INSTANCE_ID [1:0], QUEUE_ID[1:0]
 *            INSTANCE_ID - 0 = sdma0, 1 = sdma1
 *            QUEUE_ID - 0 = gfx, 1 = rlc0, 2 = rlc1
 * [79:72]  - VMID
 * [95:80]  - PASID
 * [127:96] - reserved
 */

 /**
 * cik_ih_decode_iv - decode an interrupt vector
 *
 * @adev: amdgpu_device pointer
 *
 * Decodes the interrupt vector at the current rptr
 * position and also advance the position.
 */
static void cik_ih_decode_iv(struct amdgpu_device *adev,
                             struct amdgpu_ih_ring *ih,
                             struct amdgpu_iv_entry *entry)
{
        /* wptr/rptr are in bytes! */
        u32 ring_index = ih->rptr >> 2;
        uint32_t dw[4];

        dw[0] = le32_to_cpu(ih->ring[ring_index + 0]);
        dw[1] = le32_to_cpu(ih->ring[ring_index + 1]);
        dw[2] = le32_to_cpu(ih->ring[ring_index + 2]);
        dw[3] = le32_to_cpu(ih->ring[ring_index + 3]);

        entry->client_id = AMDGPU_IRQ_CLIENTID_LEGACY;
        entry->src_id = dw[0] & 0xff;
        entry->src_data[0] = dw[1] & 0xfffffff;
        entry->ring_id = dw[2] & 0xff;
        entry->vmid = (dw[2] >> 8) & 0xff;
        entry->pasid = (dw[2] >> 16) & 0xffff;

        /* wptr/rptr are in bytes! */
        ih->rptr += 16;
}

/**
 * cik_ih_set_rptr - set the IH ring buffer rptr
 *
 * @adev: amdgpu_device pointer
 * @ih: IH ring buffer to set wptr
 *
 * Set the IH ring buffer rptr.
 */
static void cik_ih_set_rptr(struct amdgpu_device *adev,
                            struct amdgpu_ih_ring *ih)
{
        WREG32(mmIH_RB_RPTR, ih->rptr);
}

static int cik_ih_early_init(struct amdgpu_ip_block *ip_block)
{
        struct amdgpu_device *adev = ip_block->adev;
        int ret;

        ret = amdgpu_irq_add_domain(adev);
        if (ret)
                return ret;

        cik_ih_set_interrupt_funcs(adev);

        return 0;
}

static int cik_ih_sw_init(struct amdgpu_ip_block *ip_block)
{
        int r;
        struct amdgpu_device *adev = ip_block->adev;

        r = amdgpu_ih_ring_init(adev, &adev->irq.ih, 64 * 1024, false);
        if (r)
                return r;

        r = amdgpu_ih_ring_init(adev, &adev->irq.ih_soft, IH_SW_RING_SIZE, true);
        if (r)
                return r;

        r = amdgpu_irq_init(adev);

        return r;
}

static int cik_ih_sw_fini(struct amdgpu_ip_block *ip_block)
{
        struct amdgpu_device *adev = ip_block->adev;

        amdgpu_irq_fini_sw(adev);
        amdgpu_irq_remove_domain(adev);

        return 0;
}

static int cik_ih_hw_init(struct amdgpu_ip_block *ip_block)
{
        struct amdgpu_device *adev = ip_block->adev;

        return cik_ih_irq_init(adev);
}

static int cik_ih_hw_fini(struct amdgpu_ip_block *ip_block)
{
        cik_ih_irq_disable(ip_block->adev);

        return 0;
}

static int cik_ih_suspend(struct amdgpu_ip_block *ip_block)
{
        return cik_ih_hw_fini(ip_block);
}

static int cik_ih_resume(struct amdgpu_ip_block *ip_block)
{
        return cik_ih_hw_init(ip_block);
}

static bool cik_ih_is_idle(struct amdgpu_ip_block *ip_block)
{
        struct amdgpu_device *adev = ip_block->adev;
        u32 tmp = RREG32(mmSRBM_STATUS);

        if (tmp & SRBM_STATUS__IH_BUSY_MASK)
                return false;

        return true;
}

static int cik_ih_wait_for_idle(struct amdgpu_ip_block *ip_block)
{
        unsigned i;
        u32 tmp;
        struct amdgpu_device *adev = ip_block->adev;

        for (i = 0; i < adev->usec_timeout; i++) {
                /* read MC_STATUS */
                tmp = RREG32(mmSRBM_STATUS) & SRBM_STATUS__IH_BUSY_MASK;
                if (!tmp)
                        return 0;
                udelay(1);
        }
        return -ETIMEDOUT;
}

static int cik_ih_soft_reset(struct amdgpu_ip_block *ip_block)
{
        struct amdgpu_device *adev = ip_block->adev;

        u32 srbm_soft_reset = 0;
        u32 tmp = RREG32(mmSRBM_STATUS);

        if (tmp & SRBM_STATUS__IH_BUSY_MASK)
                srbm_soft_reset |= SRBM_SOFT_RESET__SOFT_RESET_IH_MASK;

        if (srbm_soft_reset) {
                tmp = RREG32(mmSRBM_SOFT_RESET);
                tmp |= srbm_soft_reset;
                dev_info(adev->dev, "SRBM_SOFT_RESET=0x%08X\n", tmp);
                WREG32(mmSRBM_SOFT_RESET, tmp);
                tmp = RREG32(mmSRBM_SOFT_RESET);

                udelay(50);

                tmp &= ~srbm_soft_reset;
                WREG32(mmSRBM_SOFT_RESET, tmp);
                tmp = RREG32(mmSRBM_SOFT_RESET);

                /* Wait a little for things to settle down */
                udelay(50);
        }

        return 0;
}

static int cik_ih_set_clockgating_state(struct amdgpu_ip_block *ip_block,
                                          enum amd_clockgating_state state)
{
        return 0;
}

static int cik_ih_set_powergating_state(struct amdgpu_ip_block *ip_block,
                                          enum amd_powergating_state state)
{
        return 0;
}

static const struct amd_ip_funcs cik_ih_ip_funcs = {
        .name = "cik_ih",
        .early_init = cik_ih_early_init,
        .sw_init = cik_ih_sw_init,
        .sw_fini = cik_ih_sw_fini,
        .hw_init = cik_ih_hw_init,
        .hw_fini = cik_ih_hw_fini,
        .suspend = cik_ih_suspend,
        .resume = cik_ih_resume,
        .is_idle = cik_ih_is_idle,
        .wait_for_idle = cik_ih_wait_for_idle,
        .soft_reset = cik_ih_soft_reset,
        .set_clockgating_state = cik_ih_set_clockgating_state,
        .set_powergating_state = cik_ih_set_powergating_state,
};

static const struct amdgpu_ih_funcs cik_ih_funcs = {
        .get_wptr = cik_ih_get_wptr,
        .decode_iv = cik_ih_decode_iv,
        .set_rptr = cik_ih_set_rptr
};

static void cik_ih_set_interrupt_funcs(struct amdgpu_device *adev)
{
        adev->irq.ih_funcs = &cik_ih_funcs;
}

const struct amdgpu_ip_block_version cik_ih_ip_block = {
        .type = AMD_IP_BLOCK_TYPE_IH,
        .major = 2,
        .minor = 0,
        .rev = 0,
        .funcs = &cik_ih_ip_funcs,
};