// SPDX-License-Identifier: GPL-2.0
/*
 * ioport.c:  Simple io mapping allocator.
 *
 * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
 * Copyright (C) 1995 Miguel de Icaza (miguel@nuclecu.unam.mx)
 *
 * 1996: sparc_free_io, 1999: ioremap()/iounmap() by Pete Zaitcev.
 *
 * 2000/01/29
 * <rth> zait: as long as pci_alloc_consistent produces something addressable, 
 *      things are ok.
 * <zaitcev> rth: no, it is relevant, because get_free_pages returns you a
 *      pointer into the big page mapping
 * <rth> zait: so what?
 * <rth> zait: remap_it_my_way(virt_to_phys(get_free_page()))
 * <zaitcev> Hmm
 * <zaitcev> Suppose I did this remap_it_my_way(virt_to_phys(get_free_page())).
 *      So far so good.
 * <zaitcev> Now, driver calls pci_free_consistent(with result of
 *      remap_it_my_way()).
 * <zaitcev> How do you find the address to pass to free_pages()?
 * <rth> zait: walk the page tables?  It's only two or three level after all.
 * <rth> zait: you have to walk them anyway to remove the mapping.
 * <zaitcev> Hmm
 * <zaitcev> Sounds reasonable
 */

#include <linux/module.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/ioport.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/pci.h>          /* struct pci_dev */
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/scatterlist.h>
#include <linux/of_device.h>

#include <asm/io.h>
#include <asm/vaddrs.h>
#include <asm/oplib.h>
#include <asm/prom.h>
#include <asm/page.h>
#include <asm/pgalloc.h>
#include <asm/dma.h>
#include <asm/iommu.h>
#include <asm/io-unit.h>
#include <asm/leon.h>

const struct sparc32_dma_ops *sparc32_dma_ops;

/* This function must make sure that caches and memory are coherent after DMA
 * On LEON systems without cache snooping it flushes the entire D-CACHE.
 */
static inline void dma_make_coherent(unsigned long pa, unsigned long len)
{
        if (sparc_cpu_model == sparc_leon) {
                if (!sparc_leon3_snooping_enabled())
                        leon_flush_dcache_all();
        }
}

static void __iomem *_sparc_ioremap(struct resource *res, u32 bus, u32 pa, int sz);
static void __iomem *_sparc_alloc_io(unsigned int busno, unsigned long phys,
    unsigned long size, char *name);
static void _sparc_free_io(struct resource *res);

static void register_proc_sparc_ioport(void);

/* This points to the next to use virtual memory for DVMA mappings */
static struct resource _sparc_dvma = {
        .name = "sparc_dvma", .start = DVMA_VADDR, .end = DVMA_END - 1
};
/* This points to the start of I/O mappings, cluable from outside. */
/*ext*/ struct resource sparc_iomap = {
        .name = "sparc_iomap", .start = IOBASE_VADDR, .end = IOBASE_END - 1
};

/*
 * Our mini-allocator...
 * Boy this is gross! We need it because we must map I/O for
 * timers and interrupt controller before the kmalloc is available.
 */

#define XNMLN  15
#define XNRES  10       /* SS-10 uses 8 */

struct xresource {
        struct resource xres;   /* Must be first */
        int xflag;              /* 1 == used */
        char xname[XNMLN+1];
};

static struct xresource xresv[XNRES];

static struct xresource *xres_alloc(void) {
        struct xresource *xrp;
        int n;

        xrp = xresv;
        for (n = 0; n < XNRES; n++) {
                if (xrp->xflag == 0) {
                        xrp->xflag = 1;
                        return xrp;
                }
                xrp++;
        }
        return NULL;
}

static void xres_free(struct xresource *xrp) {
        xrp->xflag = 0;
}

/*
 * These are typically used in PCI drivers
 * which are trying to be cross-platform.
 *
 * Bus type is always zero on IIep.
 */
void __iomem *ioremap(phys_addr_t offset, size_t size)
{
        char name[14];

        sprintf(name, "phys_%08x", (u32)offset);
        return _sparc_alloc_io(0, (unsigned long)offset, size, name);
}
EXPORT_SYMBOL(ioremap);

/*
 * Complementary to ioremap().
 */
void iounmap(volatile void __iomem *virtual)
{
        unsigned long vaddr = (unsigned long) virtual & PAGE_MASK;
        struct resource *res;

        /*
         * XXX Too slow. Can have 8192 DVMA pages on sun4m in the worst case.
         * This probably warrants some sort of hashing.
        */
        if ((res = lookup_resource(&sparc_iomap, vaddr)) == NULL) {
                printk("free_io/iounmap: cannot free %lx\n", vaddr);
                return;
        }
        _sparc_free_io(res);

        if ((char *)res >= (char*)xresv && (char *)res < (char *)&xresv[XNRES]) {
                xres_free((struct xresource *)res);
        } else {
                kfree(res);
        }
}
EXPORT_SYMBOL(iounmap);

void __iomem *of_ioremap(struct resource *res, unsigned long offset,
                         unsigned long size, char *name)
{
        return _sparc_alloc_io(res->flags & 0xF,
                               res->start + offset,
                               size, name);
}
EXPORT_SYMBOL(of_ioremap);

void of_iounmap(struct resource *res, void __iomem *base, unsigned long size)
{
        iounmap(base);
}
EXPORT_SYMBOL(of_iounmap);

/*
 * Meat of mapping
 */
static void __iomem *_sparc_alloc_io(unsigned int busno, unsigned long phys,
    unsigned long size, char *name)
{
        static int printed_full;
        struct xresource *xres;
        struct resource *res;
        char *tack;
        int tlen;
        void __iomem *va;       /* P3 diag */

        if (name == NULL) name = "???";

        if ((xres = xres_alloc()) != NULL) {
                tack = xres->xname;
                res = &xres->xres;
        } else {
                if (!printed_full) {
                        printk("ioremap: done with statics, switching to malloc\n");
                        printed_full = 1;
                }
                tlen = strlen(name);
                tack = kmalloc(sizeof (struct resource) + tlen + 1, GFP_KERNEL);
                if (tack == NULL) return NULL;
                memset(tack, 0, sizeof(struct resource));
                res = (struct resource *) tack;
                tack += sizeof (struct resource);
        }

        strlcpy(tack, name, XNMLN+1);
        res->name = tack;

        va = _sparc_ioremap(res, busno, phys, size);
        /* printk("ioremap(0x%x:%08lx[0x%lx])=%p\n", busno, phys, size, va); */ /* P3 diag */
        return va;
}

/*
 */
static void __iomem *
_sparc_ioremap(struct resource *res, u32 bus, u32 pa, int sz)
{
        unsigned long offset = ((unsigned long) pa) & (~PAGE_MASK);

        if (allocate_resource(&sparc_iomap, res,
            (offset + sz + PAGE_SIZE-1) & PAGE_MASK,
            sparc_iomap.start, sparc_iomap.end, PAGE_SIZE, NULL, NULL) != 0) {
                /* Usually we cannot see printks in this case. */
                prom_printf("alloc_io_res(%s): cannot occupy\n",
                    (res->name != NULL)? res->name: "???");
                prom_halt();
        }

        pa &= PAGE_MASK;
        srmmu_mapiorange(bus, pa, res->start, resource_size(res));

        return (void __iomem *)(unsigned long)(res->start + offset);
}

/*
 * Complementary to _sparc_ioremap().
 */
static void _sparc_free_io(struct resource *res)
{
        unsigned long plen;

        plen = resource_size(res);
        BUG_ON((plen & (PAGE_SIZE-1)) != 0);
        srmmu_unmapiorange(res->start, plen);
        release_resource(res);
}

#ifdef CONFIG_SBUS

void sbus_set_sbus64(struct device *dev, int x)
{
        printk("sbus_set_sbus64: unsupported\n");
}
EXPORT_SYMBOL(sbus_set_sbus64);

/*
 * Allocate a chunk of memory suitable for DMA.
 * Typically devices use them for control blocks.
 * CPU may access them without any explicit flushing.
 */
static void *sbus_alloc_coherent(struct device *dev, size_t len,
                                 dma_addr_t *dma_addrp, gfp_t gfp,
                                 unsigned long attrs)
{
        struct platform_device *op = to_platform_device(dev);
        unsigned long len_total = PAGE_ALIGN(len);
        unsigned long va;
        struct resource *res;
        int order;

        /* XXX why are some lengths signed, others unsigned? */
        if (len <= 0) {
                return NULL;
        }
        /* XXX So what is maxphys for us and how do drivers know it? */
        if (len > 256*1024) {                   /* __get_free_pages() limit */
                return NULL;
        }

        order = get_order(len_total);
        va = __get_free_pages(gfp, order);
        if (va == 0)
                goto err_nopages;

        if ((res = kzalloc(sizeof(struct resource), GFP_KERNEL)) == NULL)
                goto err_nomem;

        if (allocate_resource(&_sparc_dvma, res, len_total,
            _sparc_dvma.start, _sparc_dvma.end, PAGE_SIZE, NULL, NULL) != 0) {
                printk("sbus_alloc_consistent: cannot occupy 0x%lx", len_total);
                goto err_nova;
        }

        // XXX The sbus_map_dma_area does this for us below, see comments.
        // srmmu_mapiorange(0, virt_to_phys(va), res->start, len_total);
        /*
         * XXX That's where sdev would be used. Currently we load
         * all iommu tables with the same translations.
         */
        if (sbus_map_dma_area(dev, dma_addrp, va, res->start, len_total) != 0)
                goto err_noiommu;

        res->name = op->dev.of_node->name;

        return (void *)(unsigned long)res->start;

err_noiommu:
        release_resource(res);
err_nova:
        kfree(res);
err_nomem:
        free_pages(va, order);
err_nopages:
        return NULL;
}

static void sbus_free_coherent(struct device *dev, size_t n, void *p,
                               dma_addr_t ba, unsigned long attrs)
{
        struct resource *res;
        struct page *pgv;

        if ((res = lookup_resource(&_sparc_dvma,
            (unsigned long)p)) == NULL) {
                printk("sbus_free_consistent: cannot free %p\n", p);
                return;
        }

        if (((unsigned long)p & (PAGE_SIZE-1)) != 0) {
                printk("sbus_free_consistent: unaligned va %p\n", p);
                return;
        }

        n = PAGE_ALIGN(n);
        if (resource_size(res) != n) {
                printk("sbus_free_consistent: region 0x%lx asked 0x%zx\n",
                    (long)resource_size(res), n);
                return;
        }

        release_resource(res);
        kfree(res);

        pgv = virt_to_page(p);
        sbus_unmap_dma_area(dev, ba, n);

        __free_pages(pgv, get_order(n));
}

/*
 * Map a chunk of memory so that devices can see it.
 * CPU view of this memory may be inconsistent with
 * a device view and explicit flushing is necessary.
 */
static dma_addr_t sbus_map_page(struct device *dev, struct page *page,
                                unsigned long offset, size_t len,
                                enum dma_data_direction dir,
                                unsigned long attrs)
{
        void *va = page_address(page) + offset;

        /* XXX why are some lengths signed, others unsigned? */
        if (len <= 0) {
                return 0;
        }
        /* XXX So what is maxphys for us and how do drivers know it? */
        if (len > 256*1024) {                   /* __get_free_pages() limit */
                return 0;
        }
        return mmu_get_scsi_one(dev, va, len);
}

static void sbus_unmap_page(struct device *dev, dma_addr_t ba, size_t n,
                            enum dma_data_direction dir, unsigned long attrs)
{
        mmu_release_scsi_one(dev, ba, n);
}

static int sbus_map_sg(struct device *dev, struct scatterlist *sg, int n,
                       enum dma_data_direction dir, unsigned long attrs)
{
        mmu_get_scsi_sgl(dev, sg, n);
        return n;
}

static void sbus_unmap_sg(struct device *dev, struct scatterlist *sg, int n,
                          enum dma_data_direction dir, unsigned long attrs)
{
        mmu_release_scsi_sgl(dev, sg, n);
}

static void sbus_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg,
                                 int n, enum dma_data_direction dir)
{
        BUG();
}

static void sbus_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
                                    int n, enum dma_data_direction dir)
{
        BUG();
}

static int sbus_dma_supported(struct device *dev, u64 mask)
{
        return 0;
}

static const struct dma_map_ops sbus_dma_ops = {
        .alloc                  = sbus_alloc_coherent,
        .free                   = sbus_free_coherent,
        .map_page               = sbus_map_page,
        .unmap_page             = sbus_unmap_page,
        .map_sg                 = sbus_map_sg,
        .unmap_sg               = sbus_unmap_sg,
        .sync_sg_for_cpu        = sbus_sync_sg_for_cpu,
        .sync_sg_for_device     = sbus_sync_sg_for_device,
        .dma_supported          = sbus_dma_supported,
};

static int __init sparc_register_ioport(void)
{
        register_proc_sparc_ioport();

        return 0;
}

arch_initcall(sparc_register_ioport);

#endif /* CONFIG_SBUS */


/* Allocate and map kernel buffer using consistent mode DMA for a device.
 * hwdev should be valid struct pci_dev pointer for PCI devices.
 */
static void *pci32_alloc_coherent(struct device *dev, size_t len,
                                  dma_addr_t *pba, gfp_t gfp,
                                  unsigned long attrs)
{
        unsigned long len_total = PAGE_ALIGN(len);
        void *va;
        struct resource *res;
        int order;

        if (len == 0) {
                return NULL;
        }
        if (len > 256*1024) {                   /* __get_free_pages() limit */
                return NULL;
        }

        order = get_order(len_total);
        va = (void *) __get_free_pages(gfp, order);
        if (va == NULL) {
                printk("pci_alloc_consistent: no %ld pages\n", len_total>>PAGE_SHIFT);
                goto err_nopages;
        }

        if ((res = kzalloc(sizeof(struct resource), GFP_KERNEL)) == NULL) {
                printk("pci_alloc_consistent: no core\n");
                goto err_nomem;
        }

        if (allocate_resource(&_sparc_dvma, res, len_total,
            _sparc_dvma.start, _sparc_dvma.end, PAGE_SIZE, NULL, NULL) != 0) {
                printk("pci_alloc_consistent: cannot occupy 0x%lx", len_total);
                goto err_nova;
        }
        srmmu_mapiorange(0, virt_to_phys(va), res->start, len_total);

        *pba = virt_to_phys(va); /* equals virt_to_bus (R.I.P.) for us. */
        return (void *) res->start;

err_nova:
        kfree(res);
err_nomem:
        free_pages((unsigned long)va, order);
err_nopages:
        return NULL;
}

/* Free and unmap a consistent DMA buffer.
 * cpu_addr is what was returned from pci_alloc_consistent,
 * size must be the same as what as passed into pci_alloc_consistent,
 * and likewise dma_addr must be the same as what *dma_addrp was set to.
 *
 * References to the memory and mappings associated with cpu_addr/dma_addr
 * past this call are illegal.
 */
static void pci32_free_coherent(struct device *dev, size_t n, void *p,
                                dma_addr_t ba, unsigned long attrs)
{
        struct resource *res;

        if ((res = lookup_resource(&_sparc_dvma,
            (unsigned long)p)) == NULL) {
                printk("pci_free_consistent: cannot free %p\n", p);
                return;
        }

        if (((unsigned long)p & (PAGE_SIZE-1)) != 0) {
                printk("pci_free_consistent: unaligned va %p\n", p);
                return;
        }

        n = PAGE_ALIGN(n);
        if (resource_size(res) != n) {
                printk("pci_free_consistent: region 0x%lx asked 0x%lx\n",
                    (long)resource_size(res), (long)n);
                return;
        }

        dma_make_coherent(ba, n);
        srmmu_unmapiorange((unsigned long)p, n);

        release_resource(res);
        kfree(res);
        free_pages((unsigned long)phys_to_virt(ba), get_order(n));
}

/*
 * Same as pci_map_single, but with pages.
 */
static dma_addr_t pci32_map_page(struct device *dev, struct page *page,
                                 unsigned long offset, size_t size,
                                 enum dma_data_direction dir,
                                 unsigned long attrs)
{
        /* IIep is write-through, not flushing. */
        return page_to_phys(page) + offset;
}

static void pci32_unmap_page(struct device *dev, dma_addr_t ba, size_t size,
                             enum dma_data_direction dir, unsigned long attrs)
{
        if (dir != PCI_DMA_TODEVICE && !(attrs & DMA_ATTR_SKIP_CPU_SYNC))
                dma_make_coherent(ba, PAGE_ALIGN(size));
}

/* Map a set of buffers described by scatterlist in streaming
 * mode for DMA.  This is the scatter-gather version of the
 * above pci_map_single interface.  Here the scatter gather list
 * elements are each tagged with the appropriate dma address
 * and length.  They are obtained via sg_dma_{address,length}(SG).
 *
 * NOTE: An implementation may be able to use a smaller number of
 *       DMA address/length pairs than there are SG table elements.
 *       (for example via virtual mapping capabilities)
 *       The routine returns the number of addr/length pairs actually
 *       used, at most nents.
 *
 * Device ownership issues as mentioned above for pci_map_single are
 * the same here.
 */
static int pci32_map_sg(struct device *device, struct scatterlist *sgl,
                        int nents, enum dma_data_direction dir,
                        unsigned long attrs)
{
        struct scatterlist *sg;
        int n;

        /* IIep is write-through, not flushing. */
        for_each_sg(sgl, sg, nents, n) {
                sg->dma_address = sg_phys(sg);
                sg->dma_length = sg->length;
        }
        return nents;
}

/* Unmap a set of streaming mode DMA translations.
 * Again, cpu read rules concerning calls here are the same as for
 * pci_unmap_single() above.
 */
static void pci32_unmap_sg(struct device *dev, struct scatterlist *sgl,
                           int nents, enum dma_data_direction dir,
                           unsigned long attrs)
{
        struct scatterlist *sg;
        int n;

        if (dir != PCI_DMA_TODEVICE && !(attrs & DMA_ATTR_SKIP_CPU_SYNC)) {
                for_each_sg(sgl, sg, nents, n) {
                        dma_make_coherent(sg_phys(sg), PAGE_ALIGN(sg->length));
                }
        }
}

/* Make physical memory consistent for a single
 * streaming mode DMA translation before or after a transfer.
 *
 * If you perform a pci_map_single() but wish to interrogate the
 * buffer using the cpu, yet do not wish to teardown the PCI dma
 * mapping, you must call this function before doing so.  At the
 * next point you give the PCI dma address back to the card, you
 * must first perform a pci_dma_sync_for_device, and then the
 * device again owns the buffer.
 */
static void pci32_sync_single_for_cpu(struct device *dev, dma_addr_t ba,
                                      size_t size, enum dma_data_direction dir)
{
        if (dir != PCI_DMA_TODEVICE) {
                dma_make_coherent(ba, PAGE_ALIGN(size));
        }
}

static void pci32_sync_single_for_device(struct device *dev, dma_addr_t ba,
                                         size_t size, enum dma_data_direction dir)
{
        if (dir != PCI_DMA_TODEVICE) {
                dma_make_coherent(ba, PAGE_ALIGN(size));
        }
}

/* Make physical memory consistent for a set of streaming
 * mode DMA translations after a transfer.
 *
 * The same as pci_dma_sync_single_* but for a scatter-gather list,
 * same rules and usage.
 */
static void pci32_sync_sg_for_cpu(struct device *dev, struct scatterlist *sgl,
                                  int nents, enum dma_data_direction dir)
{
        struct scatterlist *sg;
        int n;

        if (dir != PCI_DMA_TODEVICE) {
                for_each_sg(sgl, sg, nents, n) {
                        dma_make_coherent(sg_phys(sg), PAGE_ALIGN(sg->length));
                }
        }
}

static void pci32_sync_sg_for_device(struct device *device, struct scatterlist *sgl,
                                     int nents, enum dma_data_direction dir)
{
        struct scatterlist *sg;
        int n;

        if (dir != PCI_DMA_TODEVICE) {
                for_each_sg(sgl, sg, nents, n) {
                        dma_make_coherent(sg_phys(sg), PAGE_ALIGN(sg->length));
                }
        }
}

/* note: leon re-uses pci32_dma_ops */
const struct dma_map_ops pci32_dma_ops = {
        .alloc                  = pci32_alloc_coherent,
        .free                   = pci32_free_coherent,
        .map_page               = pci32_map_page,
        .unmap_page             = pci32_unmap_page,
        .map_sg                 = pci32_map_sg,
        .unmap_sg               = pci32_unmap_sg,
        .sync_single_for_cpu    = pci32_sync_single_for_cpu,
        .sync_single_for_device = pci32_sync_single_for_device,
        .sync_sg_for_cpu        = pci32_sync_sg_for_cpu,
        .sync_sg_for_device     = pci32_sync_sg_for_device,
};
EXPORT_SYMBOL(pci32_dma_ops);

const struct dma_map_ops *dma_ops = &sbus_dma_ops;
EXPORT_SYMBOL(dma_ops);

#ifdef CONFIG_PROC_FS

static int sparc_io_proc_show(struct seq_file *m, void *v)
{
        struct resource *root = m->private, *r;
        const char *nm;

        for (r = root->child; r != NULL; r = r->sibling) {
                if ((nm = r->name) == NULL) nm = "???";
                seq_printf(m, "%016llx-%016llx: %s\n",
                                (unsigned long long)r->start,
                                (unsigned long long)r->end, nm);
        }

        return 0;
}

static int sparc_io_proc_open(struct inode *inode, struct file *file)
{
        return single_open(file, sparc_io_proc_show, PDE_DATA(inode));
}

static const struct file_operations sparc_io_proc_fops = {
        .owner          = THIS_MODULE,
        .open           = sparc_io_proc_open,
        .read           = seq_read,
        .llseek         = seq_lseek,
        .release        = single_release,
};
#endif /* CONFIG_PROC_FS */

static void register_proc_sparc_ioport(void)
{
#ifdef CONFIG_PROC_FS
        proc_create_data("io_map", 0, NULL, &sparc_io_proc_fops, &sparc_iomap);
        proc_create_data("dvma_map", 0, NULL, &sparc_io_proc_fops, &_sparc_dvma);
#endif
}