swh:1:snp:3c665ee4f67729f27f2e40193ab88e7298cf0fef
Tip revision: a188339ca5a396acc588e5851ed7e19f66b0ebd9 authored by Linus Torvalds on 19 May 2019, 22:47:09 UTC
Linux 5.2-rc1
Linux 5.2-rc1
Tip revision: a188339
io-unit.c
// SPDX-License-Identifier: GPL-2.0
/*
* io-unit.c: IO-UNIT specific routines for memory management.
*
* Copyright (C) 1997,1998 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/mm.h>
#include <linux/highmem.h> /* pte_offset_map => kmap_atomic */
#include <linux/bitops.h>
#include <linux/dma-mapping.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <asm/pgalloc.h>
#include <asm/pgtable.h>
#include <asm/io.h>
#include <asm/io-unit.h>
#include <asm/mxcc.h>
#include <asm/cacheflush.h>
#include <asm/tlbflush.h>
#include <asm/dma.h>
#include <asm/oplib.h>
#include "mm_32.h"
/* #define IOUNIT_DEBUG */
#ifdef IOUNIT_DEBUG
#define IOD(x) printk(x)
#else
#define IOD(x) do { } while (0)
#endif
#define IOPERM (IOUPTE_CACHE | IOUPTE_WRITE | IOUPTE_VALID)
#define MKIOPTE(phys) __iopte((((phys)>>4) & IOUPTE_PAGE) | IOPERM)
static void __init iounit_iommu_init(struct platform_device *op)
{
struct iounit_struct *iounit;
iopte_t __iomem *xpt;
iopte_t __iomem *xptend;
iounit = kzalloc(sizeof(struct iounit_struct), GFP_ATOMIC);
if (!iounit) {
prom_printf("SUN4D: Cannot alloc iounit, halting.\n");
prom_halt();
}
iounit->limit[0] = IOUNIT_BMAP1_START;
iounit->limit[1] = IOUNIT_BMAP2_START;
iounit->limit[2] = IOUNIT_BMAPM_START;
iounit->limit[3] = IOUNIT_BMAPM_END;
iounit->rotor[1] = IOUNIT_BMAP2_START;
iounit->rotor[2] = IOUNIT_BMAPM_START;
xpt = of_ioremap(&op->resource[2], 0, PAGE_SIZE * 16, "XPT");
if (!xpt) {
prom_printf("SUN4D: Cannot map External Page Table.");
prom_halt();
}
op->dev.archdata.iommu = iounit;
iounit->page_table = xpt;
spin_lock_init(&iounit->lock);
xptend = iounit->page_table + (16 * PAGE_SIZE) / sizeof(iopte_t);
for (; xpt < xptend; xpt++)
sbus_writel(0, xpt);
}
static int __init iounit_init(void)
{
extern void sun4d_init_sbi_irq(void);
struct device_node *dp;
for_each_node_by_name(dp, "sbi") {
struct platform_device *op = of_find_device_by_node(dp);
iounit_iommu_init(op);
of_propagate_archdata(op);
}
sun4d_init_sbi_irq();
return 0;
}
subsys_initcall(iounit_init);
/* One has to hold iounit->lock to call this */
static unsigned long iounit_get_area(struct iounit_struct *iounit, unsigned long vaddr, int size)
{
int i, j, k, npages;
unsigned long rotor, scan, limit;
iopte_t iopte;
npages = ((vaddr & ~PAGE_MASK) + size + (PAGE_SIZE-1)) >> PAGE_SHIFT;
/* A tiny bit of magic ingredience :) */
switch (npages) {
case 1: i = 0x0231; break;
case 2: i = 0x0132; break;
default: i = 0x0213; break;
}
IOD(("iounit_get_area(%08lx,%d[%d])=", vaddr, size, npages));
next: j = (i & 15);
rotor = iounit->rotor[j - 1];
limit = iounit->limit[j];
scan = rotor;
nexti: scan = find_next_zero_bit(iounit->bmap, limit, scan);
if (scan + npages > limit) {
if (limit != rotor) {
limit = rotor;
scan = iounit->limit[j - 1];
goto nexti;
}
i >>= 4;
if (!(i & 15))
panic("iounit_get_area: Couldn't find free iopte slots for (%08lx,%d)\n", vaddr, size);
goto next;
}
for (k = 1, scan++; k < npages; k++)
if (test_bit(scan++, iounit->bmap))
goto nexti;
iounit->rotor[j - 1] = (scan < limit) ? scan : iounit->limit[j - 1];
scan -= npages;
iopte = MKIOPTE(__pa(vaddr & PAGE_MASK));
vaddr = IOUNIT_DMA_BASE + (scan << PAGE_SHIFT) + (vaddr & ~PAGE_MASK);
for (k = 0; k < npages; k++, iopte = __iopte(iopte_val(iopte) + 0x100), scan++) {
set_bit(scan, iounit->bmap);
sbus_writel(iopte_val(iopte), &iounit->page_table[scan]);
}
IOD(("%08lx\n", vaddr));
return vaddr;
}
static dma_addr_t iounit_map_page(struct device *dev, struct page *page,
unsigned long offset, size_t len, enum dma_data_direction dir,
unsigned long attrs)
{
void *vaddr = page_address(page) + offset;
struct iounit_struct *iounit = dev->archdata.iommu;
unsigned long ret, flags;
/* XXX So what is maxphys for us and how do drivers know it? */
if (!len || len > 256 * 1024)
return DMA_MAPPING_ERROR;
spin_lock_irqsave(&iounit->lock, flags);
ret = iounit_get_area(iounit, (unsigned long)vaddr, len);
spin_unlock_irqrestore(&iounit->lock, flags);
return ret;
}
static int iounit_map_sg(struct device *dev, struct scatterlist *sgl, int nents,
enum dma_data_direction dir, unsigned long attrs)
{
struct iounit_struct *iounit = dev->archdata.iommu;
struct scatterlist *sg;
unsigned long flags;
int i;
/* FIXME: Cache some resolved pages - often several sg entries are to the same page */
spin_lock_irqsave(&iounit->lock, flags);
for_each_sg(sgl, sg, nents, i) {
sg->dma_address = iounit_get_area(iounit, (unsigned long) sg_virt(sg), sg->length);
sg->dma_length = sg->length;
}
spin_unlock_irqrestore(&iounit->lock, flags);
return nents;
}
static void iounit_unmap_page(struct device *dev, dma_addr_t vaddr, size_t len,
enum dma_data_direction dir, unsigned long attrs)
{
struct iounit_struct *iounit = dev->archdata.iommu;
unsigned long flags;
spin_lock_irqsave(&iounit->lock, flags);
len = ((vaddr & ~PAGE_MASK) + len + (PAGE_SIZE-1)) >> PAGE_SHIFT;
vaddr = (vaddr - IOUNIT_DMA_BASE) >> PAGE_SHIFT;
IOD(("iounit_release %08lx-%08lx\n", (long)vaddr, (long)len+vaddr));
for (len += vaddr; vaddr < len; vaddr++)
clear_bit(vaddr, iounit->bmap);
spin_unlock_irqrestore(&iounit->lock, flags);
}
static void iounit_unmap_sg(struct device *dev, struct scatterlist *sgl,
int nents, enum dma_data_direction dir, unsigned long attrs)
{
struct iounit_struct *iounit = dev->archdata.iommu;
unsigned long flags, vaddr, len;
struct scatterlist *sg;
int i;
spin_lock_irqsave(&iounit->lock, flags);
for_each_sg(sgl, sg, nents, i) {
len = ((sg->dma_address & ~PAGE_MASK) + sg->length + (PAGE_SIZE-1)) >> PAGE_SHIFT;
vaddr = (sg->dma_address - IOUNIT_DMA_BASE) >> PAGE_SHIFT;
IOD(("iounit_release %08lx-%08lx\n", (long)vaddr, (long)len+vaddr));
for (len += vaddr; vaddr < len; vaddr++)
clear_bit(vaddr, iounit->bmap);
}
spin_unlock_irqrestore(&iounit->lock, flags);
}
#ifdef CONFIG_SBUS
static void *iounit_alloc(struct device *dev, size_t len,
dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs)
{
struct iounit_struct *iounit = dev->archdata.iommu;
unsigned long va, addr, page, end, ret;
pgprot_t dvma_prot;
iopte_t __iomem *iopte;
/* XXX So what is maxphys for us and how do drivers know it? */
if (!len || len > 256 * 1024)
return NULL;
len = PAGE_ALIGN(len);
va = __get_free_pages(gfp | __GFP_ZERO, get_order(len));
if (!va)
return NULL;
addr = ret = sparc_dma_alloc_resource(dev, len);
if (!addr)
goto out_free_pages;
*dma_handle = addr;
dvma_prot = __pgprot(SRMMU_CACHE | SRMMU_ET_PTE | SRMMU_PRIV);
end = PAGE_ALIGN((addr + len));
while(addr < end) {
page = va;
{
pgd_t *pgdp;
pmd_t *pmdp;
pte_t *ptep;
long i;
pgdp = pgd_offset(&init_mm, addr);
pmdp = pmd_offset(pgdp, addr);
ptep = pte_offset_map(pmdp, addr);
set_pte(ptep, mk_pte(virt_to_page(page), dvma_prot));
i = ((addr - IOUNIT_DMA_BASE) >> PAGE_SHIFT);
iopte = iounit->page_table + i;
sbus_writel(iopte_val(MKIOPTE(__pa(page))), iopte);
}
addr += PAGE_SIZE;
va += PAGE_SIZE;
}
flush_cache_all();
flush_tlb_all();
return (void *)ret;
out_free_pages:
free_pages(va, get_order(len));
return NULL;
}
static void iounit_free(struct device *dev, size_t size, void *cpu_addr,
dma_addr_t dma_addr, unsigned long attrs)
{
/* XXX Somebody please fill this in */
}
#endif
static const struct dma_map_ops iounit_dma_ops = {
#ifdef CONFIG_SBUS
.alloc = iounit_alloc,
.free = iounit_free,
#endif
.map_page = iounit_map_page,
.unmap_page = iounit_unmap_page,
.map_sg = iounit_map_sg,
.unmap_sg = iounit_unmap_sg,
};
void __init ld_mmu_iounit(void)
{
dma_ops = &iounit_dma_ops;
}