/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (C) 2001-2005 Silicon Graphics, Inc. All rights reserved.
 */

#include <linux/types.h>
#include <linux/pci.h>
#include <linux/export.h>
#include <asm/sn/addrs.h>
#include <asm/sn/geo.h>
#include <asm/sn/pcibr_provider.h>
#include <asm/sn/pcibus_provider_defs.h>
#include <asm/sn/pcidev.h>
#include <asm/sn/pic.h>
#include <asm/sn/sn_sal.h>
#include <asm/sn/tiocp.h>
#include "tio.h"
#include "xtalk/xwidgetdev.h"
#include "xtalk/hubdev.h"

extern int sn_ioif_inited;

/* =====================================================================
 *    DMA MANAGEMENT
 *
 *      The Bridge ASIC provides three methods of doing DMA: via a "direct map"
 *      register available in 32-bit PCI space (which selects a contiguous 2G
 *      address space on some other widget), via "direct" addressing via 64-bit
 *      PCI space (all destination information comes from the PCI address,
 *      including transfer attributes), and via a "mapped" region that allows 
 *      a bunch of different small mappings to be established with the PMU.
 *
 *      For efficiency, we most prefer to use the 32bit direct mapping facility,
 *      since it requires no resource allocations. The advantage of using the
 *      PMU over the 64-bit direct is that single-cycle PCI addressing can be
 *      used; the advantage of using 64-bit direct over PMU addressing is that
 *      we do not have to allocate entries in the PMU.
 */

static dma_addr_t
pcibr_dmamap_ate32(struct pcidev_info *info,
                   u64 paddr, size_t req_size, u64 flags, int dma_flags)
{

        struct pcidev_info *pcidev_info = info->pdi_host_pcidev_info;
        struct pcibus_info *pcibus_info = (struct pcibus_info *)pcidev_info->
            pdi_pcibus_info;
        u8 internal_device = (PCI_SLOT(pcidev_info->pdi_host_pcidev_info->
                                            pdi_linux_pcidev->devfn)) - 1;
        int ate_count;
        int ate_index;
        u64 ate_flags = flags | PCI32_ATE_V;
        u64 ate;
        u64 pci_addr;
        u64 xio_addr;
        u64 offset;

        /* PIC in PCI-X mode does not supports 32bit PageMap mode */
        if (IS_PIC_SOFT(pcibus_info) && IS_PCIX(pcibus_info)) {
                return 0;
        }

        /* Calculate the number of ATEs needed. */
        if (!(MINIMAL_ATE_FLAG(paddr, req_size))) {
                ate_count = IOPG((IOPGSIZE - 1) /* worst case start offset */
                                 +req_size      /* max mapping bytes */
                                 - 1) + 1;      /* round UP */
        } else {                /* assume requested target is page aligned */
                ate_count = IOPG(req_size       /* max mapping bytes */
                                 - 1) + 1;      /* round UP */
        }

        /* Get the number of ATEs required. */
        ate_index = pcibr_ate_alloc(pcibus_info, ate_count);
        if (ate_index < 0)
                return 0;

        /* In PCI-X mode, Prefetch not supported */
        if (IS_PCIX(pcibus_info))
                ate_flags &= ~(PCI32_ATE_PREF);

        if (SN_DMA_ADDRTYPE(dma_flags == SN_DMA_ADDR_PHYS))
                xio_addr = IS_PIC_SOFT(pcibus_info) ? PHYS_TO_DMA(paddr) :
                                                      PHYS_TO_TIODMA(paddr);
        else
                xio_addr = paddr;

        offset = IOPGOFF(xio_addr);
        ate = ate_flags | (xio_addr - offset);

        /* If PIC, put the targetid in the ATE */
        if (IS_PIC_SOFT(pcibus_info)) {
                ate |= (pcibus_info->pbi_hub_xid << PIC_ATE_TARGETID_SHFT);
        }

        /*
         * If we're mapping for MSI, set the MSI bit in the ATE.  If it's a
         * TIOCP based pci bus, we also need to set the PIO bit in the ATE.
         */
        if (dma_flags & SN_DMA_MSI) {
                ate |= PCI32_ATE_MSI;
                if (IS_TIOCP_SOFT(pcibus_info))
                        ate |= PCI32_ATE_PIO;
        }

        ate_write(pcibus_info, ate_index, ate_count, ate);

        /*
         * Set up the DMA mapped Address.
         */
        pci_addr = PCI32_MAPPED_BASE + offset + IOPGSIZE * ate_index;

        /*
         * If swap was set in device in pcibr_endian_set()
         * we need to turn swapping on.
         */
        if (pcibus_info->pbi_devreg[internal_device] & PCIBR_DEV_SWAP_DIR)
                ATE_SWAP_ON(pci_addr);


        return pci_addr;
}

static dma_addr_t
pcibr_dmatrans_direct64(struct pcidev_info * info, u64 paddr,
                        u64 dma_attributes, int dma_flags)
{
        struct pcibus_info *pcibus_info = (struct pcibus_info *)
            ((info->pdi_host_pcidev_info)->pdi_pcibus_info);
        u64 pci_addr;

        /* Translate to Crosstalk View of Physical Address */
        if (SN_DMA_ADDRTYPE(dma_flags) == SN_DMA_ADDR_PHYS)
                pci_addr = IS_PIC_SOFT(pcibus_info) ?
                                PHYS_TO_DMA(paddr) :
                                PHYS_TO_TIODMA(paddr);
        else
                pci_addr = paddr;
        pci_addr |= dma_attributes;

        /* Handle Bus mode */
        if (IS_PCIX(pcibus_info))
                pci_addr &= ~PCI64_ATTR_PREF;

        /* Handle Bridge Chipset differences */
        if (IS_PIC_SOFT(pcibus_info)) {
                pci_addr |=
                    ((u64) pcibus_info->
                     pbi_hub_xid << PIC_PCI64_ATTR_TARG_SHFT);
        } else
                pci_addr |= (dma_flags & SN_DMA_MSI) ?
                                TIOCP_PCI64_CMDTYPE_MSI :
                                TIOCP_PCI64_CMDTYPE_MEM;

        /* If PCI mode, func zero uses VCHAN0, every other func uses VCHAN1 */
        if (!IS_PCIX(pcibus_info) && PCI_FUNC(info->pdi_linux_pcidev->devfn))
                pci_addr |= PCI64_ATTR_VIRTUAL;

        return pci_addr;
}

static dma_addr_t
pcibr_dmatrans_direct32(struct pcidev_info * info,
                        u64 paddr, size_t req_size, u64 flags, int dma_flags)
{
        struct pcidev_info *pcidev_info = info->pdi_host_pcidev_info;
        struct pcibus_info *pcibus_info = (struct pcibus_info *)pcidev_info->
            pdi_pcibus_info;
        u64 xio_addr;

        u64 xio_base;
        u64 offset;
        u64 endoff;

        if (IS_PCIX(pcibus_info)) {
                return 0;
        }

        if (dma_flags & SN_DMA_MSI)
                return 0;

        if (SN_DMA_ADDRTYPE(dma_flags) == SN_DMA_ADDR_PHYS)
                xio_addr = IS_PIC_SOFT(pcibus_info) ? PHYS_TO_DMA(paddr) :
                                                      PHYS_TO_TIODMA(paddr);
        else
                xio_addr = paddr;

        xio_base = pcibus_info->pbi_dir_xbase;
        offset = xio_addr - xio_base;
        endoff = req_size + offset;
        if ((req_size > (1ULL << 31)) ||        /* Too Big */
            (xio_addr < xio_base) ||    /* Out of range for mappings */
            (endoff > (1ULL << 31))) {  /* Too Big */
                return 0;
        }

        return PCI32_DIRECT_BASE | offset;
}

/*
 * Wrapper routine for freeing DMA maps
 * DMA mappings for Direct 64 and 32 do not have any DMA maps.
 */
void
pcibr_dma_unmap(struct pci_dev *hwdev, dma_addr_t dma_handle, int direction)
{
        struct pcidev_info *pcidev_info = SN_PCIDEV_INFO(hwdev);
        struct pcibus_info *pcibus_info =
            (struct pcibus_info *)pcidev_info->pdi_pcibus_info;

        if (IS_PCI32_MAPPED(dma_handle)) {
                int ate_index;

                ate_index =
                    IOPG((ATE_SWAP_OFF(dma_handle) - PCI32_MAPPED_BASE));
                pcibr_ate_free(pcibus_info, ate_index);
        }
}

/*
 * On SN systems there is a race condition between a PIO read response and 
 * DMA's.  In rare cases, the read response may beat the DMA, causing the
 * driver to think that data in memory is complete and meaningful.  This code
 * eliminates that race.  This routine is called by the PIO read routines
 * after doing the read.  For PIC this routine then forces a fake interrupt
 * on another line, which is logically associated with the slot that the PIO
 * is addressed to.  It then spins while watching the memory location that
 * the interrupt is targeted to.  When the interrupt response arrives, we 
 * are sure that the DMA has landed in memory and it is safe for the driver
 * to proceed.  For TIOCP use the Device(x) Write Request Buffer Flush 
 * Bridge register since it ensures the data has entered the coherence domain,
 * unlike the PIC Device(x) Write Request Buffer Flush register.
 */

void sn_dma_flush(u64 addr)
{
        nasid_t nasid;
        int is_tio;
        int wid_num;
        int i, j;
        unsigned long flags;
        u64 itte;
        struct hubdev_info *hubinfo;
        struct sn_flush_device_kernel *p;
        struct sn_flush_device_common *common;
        struct sn_flush_nasid_entry *flush_nasid_list;

        if (!sn_ioif_inited)
                return;

        nasid = NASID_GET(addr);
        if (-1 == nasid_to_cnodeid(nasid))
                return;

        hubinfo = (NODEPDA(nasid_to_cnodeid(nasid)))->pdinfo;

        BUG_ON(!hubinfo);

        flush_nasid_list = &hubinfo->hdi_flush_nasid_list;
        if (flush_nasid_list->widget_p == NULL)
                return;

        is_tio = (nasid & 1);
        if (is_tio) {
                int itte_index;

                if (TIO_HWIN(addr))
                        itte_index = 0;
                else if (TIO_BWIN_WINDOWNUM(addr))
                        itte_index = TIO_BWIN_WINDOWNUM(addr);
                else
                        itte_index = -1;

                if (itte_index >= 0) {
                        itte = flush_nasid_list->iio_itte[itte_index];
                        if (! TIO_ITTE_VALID(itte))
                                return;
                        wid_num = TIO_ITTE_WIDGET(itte);
                } else
                        wid_num = TIO_SWIN_WIDGETNUM(addr);
        } else {
                if (BWIN_WINDOWNUM(addr)) {
                        itte = flush_nasid_list->iio_itte[BWIN_WINDOWNUM(addr)];
                        wid_num = IIO_ITTE_WIDGET(itte);
                } else
                        wid_num = SWIN_WIDGETNUM(addr);
        }
        if (flush_nasid_list->widget_p[wid_num] == NULL)
                return;
        p = &flush_nasid_list->widget_p[wid_num][0];

        /* find a matching BAR */
        for (i = 0; i < DEV_PER_WIDGET; i++,p++) {
                common = p->common;
                for (j = 0; j < PCI_ROM_RESOURCE; j++) {
                        if (common->sfdl_bar_list[j].start == 0)
                                break;
                        if (addr >= common->sfdl_bar_list[j].start
                            && addr <= common->sfdl_bar_list[j].end)
                                break;
                }
                if (j < PCI_ROM_RESOURCE && common->sfdl_bar_list[j].start != 0)
                        break;
        }

        /* if no matching BAR, return without doing anything. */
        if (i == DEV_PER_WIDGET)
                return;

        /*
         * For TIOCP use the Device(x) Write Request Buffer Flush Bridge
         * register since it ensures the data has entered the coherence
         * domain, unlike PIC.
         */
        if (is_tio) {
                /*
                 * Note:  devices behind TIOCE should never be matched in the
                 * above code, and so the following code is PIC/CP centric.
                 * If CE ever needs the sn_dma_flush mechanism, we will have
                 * to account for that here and in tioce_bus_fixup().
                 */
                u32 tio_id = HUB_L(TIO_IOSPACE_ADDR(nasid, TIO_NODE_ID));
                u32 revnum = XWIDGET_PART_REV_NUM(tio_id);

                /* TIOCP BRINGUP WAR (PV907516): Don't write buffer flush reg */
                if ((1 << XWIDGET_PART_REV_NUM_REV(revnum)) & PV907516) {
                        return;
                } else {
                        pcireg_wrb_flush_get(common->sfdl_pcibus_info,
                                             (common->sfdl_slot - 1));
                }
        } else {
                spin_lock_irqsave(&p->sfdl_flush_lock, flags);
                *common->sfdl_flush_addr = 0;

                /* force an interrupt. */
                *(volatile u32 *)(common->sfdl_force_int_addr) = 1;

                /* wait for the interrupt to come back. */
                while (*(common->sfdl_flush_addr) != 0x10f)
                        cpu_relax();

                /* okay, everything is synched up. */
                spin_unlock_irqrestore(&p->sfdl_flush_lock, flags);
        }
        return;
}

/*
 * DMA interfaces.  Called from pci_dma.c routines.
 */

dma_addr_t
pcibr_dma_map(struct pci_dev * hwdev, unsigned long phys_addr, size_t size, int dma_flags)
{
        dma_addr_t dma_handle;
        struct pcidev_info *pcidev_info = SN_PCIDEV_INFO(hwdev);

        /* SN cannot support DMA addresses smaller than 32 bits. */
        if (hwdev->dma_mask < 0x7fffffff) {
                return 0;
        }

        if (hwdev->dma_mask == ~0UL) {
                /*
                 * Handle the most common case: 64 bit cards.  This
                 * call should always succeed.
                 */

                dma_handle = pcibr_dmatrans_direct64(pcidev_info, phys_addr,
                                                     PCI64_ATTR_PREF, dma_flags);
        } else {
                /* Handle 32-63 bit cards via direct mapping */
                dma_handle = pcibr_dmatrans_direct32(pcidev_info, phys_addr,
                                                     size, 0, dma_flags);
                if (!dma_handle) {
                        /*
                         * It is a 32 bit card and we cannot do direct mapping,
                         * so we use an ATE.
                         */

                        dma_handle = pcibr_dmamap_ate32(pcidev_info, phys_addr,
                                                        size, PCI32_ATE_PREF,
                                                        dma_flags);
                }
        }

        return dma_handle;
}

dma_addr_t
pcibr_dma_map_consistent(struct pci_dev * hwdev, unsigned long phys_addr,
                         size_t size, int dma_flags)
{
        dma_addr_t dma_handle;
        struct pcidev_info *pcidev_info = SN_PCIDEV_INFO(hwdev);

        if (hwdev->dev.coherent_dma_mask == ~0UL) {
                dma_handle = pcibr_dmatrans_direct64(pcidev_info, phys_addr,
                                            PCI64_ATTR_BAR, dma_flags);
        } else {
                dma_handle = (dma_addr_t) pcibr_dmamap_ate32(pcidev_info,
                                                    phys_addr, size,
                                                    PCI32_ATE_BAR, dma_flags);
        }

        return dma_handle;
}

EXPORT_SYMBOL(sn_dma_flush);