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OpenCloudOS-Kernel/arch/s390/pci/pci_dma.c

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// SPDX-License-Identifier: GPL-2.0
/*
* Copyright IBM Corp. 2012
*
* Author(s):
* Jan Glauber <jang@linux.vnet.ibm.com>
*/
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/export.h>
#include <linux/iommu-helper.h>
#include <linux/dma-mapping.h>
#include <linux/vmalloc.h>
#include <linux/pci.h>
#include <asm/pci_dma.h>
static struct kmem_cache *dma_region_table_cache;
static struct kmem_cache *dma_page_table_cache;
static int s390_iommu_strict;
static int zpci_refresh_global(struct zpci_dev *zdev)
{
return zpci_refresh_trans((u64) zdev->fh << 32, zdev->start_dma,
zdev->iommu_pages * PAGE_SIZE);
}
unsigned long *dma_alloc_cpu_table(void)
{
unsigned long *table, *entry;
table = kmem_cache_alloc(dma_region_table_cache, GFP_ATOMIC);
if (!table)
return NULL;
for (entry = table; entry < table + ZPCI_TABLE_ENTRIES; entry++)
*entry = ZPCI_TABLE_INVALID;
return table;
}
static void dma_free_cpu_table(void *table)
{
kmem_cache_free(dma_region_table_cache, table);
}
static unsigned long *dma_alloc_page_table(void)
{
unsigned long *table, *entry;
table = kmem_cache_alloc(dma_page_table_cache, GFP_ATOMIC);
if (!table)
return NULL;
for (entry = table; entry < table + ZPCI_PT_ENTRIES; entry++)
*entry = ZPCI_PTE_INVALID;
return table;
}
static void dma_free_page_table(void *table)
{
kmem_cache_free(dma_page_table_cache, table);
}
static unsigned long *dma_get_seg_table_origin(unsigned long *entry)
{
unsigned long *sto;
if (reg_entry_isvalid(*entry))
sto = get_rt_sto(*entry);
else {
sto = dma_alloc_cpu_table();
if (!sto)
return NULL;
set_rt_sto(entry, sto);
validate_rt_entry(entry);
entry_clr_protected(entry);
}
return sto;
}
static unsigned long *dma_get_page_table_origin(unsigned long *entry)
{
unsigned long *pto;
if (reg_entry_isvalid(*entry))
pto = get_st_pto(*entry);
else {
pto = dma_alloc_page_table();
if (!pto)
return NULL;
set_st_pto(entry, pto);
validate_st_entry(entry);
entry_clr_protected(entry);
}
return pto;
}
unsigned long *dma_walk_cpu_trans(unsigned long *rto, dma_addr_t dma_addr)
{
unsigned long *sto, *pto;
unsigned int rtx, sx, px;
rtx = calc_rtx(dma_addr);
sto = dma_get_seg_table_origin(&rto[rtx]);
if (!sto)
return NULL;
sx = calc_sx(dma_addr);
pto = dma_get_page_table_origin(&sto[sx]);
if (!pto)
return NULL;
px = calc_px(dma_addr);
return &pto[px];
}
void dma_update_cpu_trans(unsigned long *entry, void *page_addr, int flags)
{
if (flags & ZPCI_PTE_INVALID) {
invalidate_pt_entry(entry);
} else {
set_pt_pfaa(entry, page_addr);
validate_pt_entry(entry);
}
if (flags & ZPCI_TABLE_PROTECTED)
entry_set_protected(entry);
else
entry_clr_protected(entry);
}
static int __dma_update_trans(struct zpci_dev *zdev, unsigned long pa,
dma_addr_t dma_addr, size_t size, int flags)
{
unsigned int nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;
u8 *page_addr = (u8 *) (pa & PAGE_MASK);
unsigned long irq_flags;
unsigned long *entry;
int i, rc = 0;
if (!nr_pages)
return -EINVAL;
spin_lock_irqsave(&zdev->dma_table_lock, irq_flags);
if (!zdev->dma_table) {
rc = -EINVAL;
goto out_unlock;
}
for (i = 0; i < nr_pages; i++) {
entry = dma_walk_cpu_trans(zdev->dma_table, dma_addr);
if (!entry) {
rc = -ENOMEM;
goto undo_cpu_trans;
}
dma_update_cpu_trans(entry, page_addr, flags);
page_addr += PAGE_SIZE;
dma_addr += PAGE_SIZE;
}
undo_cpu_trans:
if (rc && ((flags & ZPCI_PTE_VALID_MASK) == ZPCI_PTE_VALID)) {
flags = ZPCI_PTE_INVALID;
while (i-- > 0) {
page_addr -= PAGE_SIZE;
dma_addr -= PAGE_SIZE;
entry = dma_walk_cpu_trans(zdev->dma_table, dma_addr);
if (!entry)
break;
dma_update_cpu_trans(entry, page_addr, flags);
}
}
out_unlock:
spin_unlock_irqrestore(&zdev->dma_table_lock, irq_flags);
return rc;
}
static int __dma_purge_tlb(struct zpci_dev *zdev, dma_addr_t dma_addr,
size_t size, int flags)
{
unsigned long irqflags;
int ret;
/*
* With zdev->tlb_refresh == 0, rpcit is not required to establish new
* translations when previously invalid translation-table entries are
* validated. With lazy unmap, rpcit is skipped for previously valid
* entries, but a global rpcit is then required before any address can
* be re-used, i.e. after each iommu bitmap wrap-around.
*/
if ((flags & ZPCI_PTE_VALID_MASK) == ZPCI_PTE_VALID) {
if (!zdev->tlb_refresh)
return 0;
} else {
if (!s390_iommu_strict)
return 0;
}
ret = zpci_refresh_trans((u64) zdev->fh << 32, dma_addr,
PAGE_ALIGN(size));
if (ret == -ENOMEM && !s390_iommu_strict) {
/* enable the hypervisor to free some resources */
if (zpci_refresh_global(zdev))
goto out;
spin_lock_irqsave(&zdev->iommu_bitmap_lock, irqflags);
bitmap_andnot(zdev->iommu_bitmap, zdev->iommu_bitmap,
zdev->lazy_bitmap, zdev->iommu_pages);
bitmap_zero(zdev->lazy_bitmap, zdev->iommu_pages);
spin_unlock_irqrestore(&zdev->iommu_bitmap_lock, irqflags);
ret = 0;
}
out:
return ret;
}
static int dma_update_trans(struct zpci_dev *zdev, unsigned long pa,
dma_addr_t dma_addr, size_t size, int flags)
{
int rc;
rc = __dma_update_trans(zdev, pa, dma_addr, size, flags);
if (rc)
return rc;
rc = __dma_purge_tlb(zdev, dma_addr, size, flags);
if (rc && ((flags & ZPCI_PTE_VALID_MASK) == ZPCI_PTE_VALID))
__dma_update_trans(zdev, pa, dma_addr, size, ZPCI_PTE_INVALID);
return rc;
}
void dma_free_seg_table(unsigned long entry)
{
unsigned long *sto = get_rt_sto(entry);
int sx;
for (sx = 0; sx < ZPCI_TABLE_ENTRIES; sx++)
if (reg_entry_isvalid(sto[sx]))
dma_free_page_table(get_st_pto(sto[sx]));
dma_free_cpu_table(sto);
}
void dma_cleanup_tables(unsigned long *table)
{
int rtx;
if (!table)
return;
for (rtx = 0; rtx < ZPCI_TABLE_ENTRIES; rtx++)
if (reg_entry_isvalid(table[rtx]))
dma_free_seg_table(table[rtx]);
dma_free_cpu_table(table);
}
static unsigned long __dma_alloc_iommu(struct device *dev,
unsigned long start, int size)
{
struct zpci_dev *zdev = to_zpci(to_pci_dev(dev));
unsigned long boundary_size;
boundary_size = ALIGN(dma_get_seg_boundary(dev) + 1,
PAGE_SIZE) >> PAGE_SHIFT;
return iommu_area_alloc(zdev->iommu_bitmap, zdev->iommu_pages,
start, size, zdev->start_dma >> PAGE_SHIFT,
boundary_size, 0);
}
static dma_addr_t dma_alloc_address(struct device *dev, int size)
{
struct zpci_dev *zdev = to_zpci(to_pci_dev(dev));
unsigned long offset, flags;
spin_lock_irqsave(&zdev->iommu_bitmap_lock, flags);
offset = __dma_alloc_iommu(dev, zdev->next_bit, size);
if (offset == -1) {
if (!s390_iommu_strict) {
/* global flush before DMA addresses are reused */
if (zpci_refresh_global(zdev))
goto out_error;
bitmap_andnot(zdev->iommu_bitmap, zdev->iommu_bitmap,
zdev->lazy_bitmap, zdev->iommu_pages);
bitmap_zero(zdev->lazy_bitmap, zdev->iommu_pages);
}
/* wrap-around */
offset = __dma_alloc_iommu(dev, 0, size);
if (offset == -1)
goto out_error;
}
zdev->next_bit = offset + size;
spin_unlock_irqrestore(&zdev->iommu_bitmap_lock, flags);
return zdev->start_dma + offset * PAGE_SIZE;
out_error:
spin_unlock_irqrestore(&zdev->iommu_bitmap_lock, flags);
return DMA_MAPPING_ERROR;
}
static void dma_free_address(struct device *dev, dma_addr_t dma_addr, int size)
{
struct zpci_dev *zdev = to_zpci(to_pci_dev(dev));
unsigned long flags, offset;
offset = (dma_addr - zdev->start_dma) >> PAGE_SHIFT;
spin_lock_irqsave(&zdev->iommu_bitmap_lock, flags);
if (!zdev->iommu_bitmap)
goto out;
if (s390_iommu_strict)
bitmap_clear(zdev->iommu_bitmap, offset, size);
else
bitmap_set(zdev->lazy_bitmap, offset, size);
out:
spin_unlock_irqrestore(&zdev->iommu_bitmap_lock, flags);
}
static inline void zpci_err_dma(unsigned long rc, unsigned long addr)
{
struct {
unsigned long rc;
unsigned long addr;
} __packed data = {rc, addr};
zpci_err_hex(&data, sizeof(data));
}
static dma_addr_t s390_dma_map_pages(struct device *dev, struct page *page,
unsigned long offset, size_t size,
enum dma_data_direction direction,
unsigned long attrs)
{
struct zpci_dev *zdev = to_zpci(to_pci_dev(dev));
unsigned long pa = page_to_phys(page) + offset;
int flags = ZPCI_PTE_VALID;
unsigned long nr_pages;
dma_addr_t dma_addr;
int ret;
/* This rounds up number of pages based on size and offset */
nr_pages = iommu_num_pages(pa, size, PAGE_SIZE);
dma_addr = dma_alloc_address(dev, nr_pages);
if (dma_addr == DMA_MAPPING_ERROR) {
ret = -ENOSPC;
goto out_err;
}
/* Use rounded up size */
size = nr_pages * PAGE_SIZE;
if (direction == DMA_NONE || direction == DMA_TO_DEVICE)
flags |= ZPCI_TABLE_PROTECTED;
ret = dma_update_trans(zdev, pa, dma_addr, size, flags);
if (ret)
goto out_free;
atomic64_add(nr_pages, &zdev->mapped_pages);
return dma_addr + (offset & ~PAGE_MASK);
out_free:
dma_free_address(dev, dma_addr, nr_pages);
out_err:
zpci_err("map error:\n");
zpci_err_dma(ret, pa);
return DMA_MAPPING_ERROR;
}
static void s390_dma_unmap_pages(struct device *dev, dma_addr_t dma_addr,
size_t size, enum dma_data_direction direction,
unsigned long attrs)
{
struct zpci_dev *zdev = to_zpci(to_pci_dev(dev));
int npages, ret;
npages = iommu_num_pages(dma_addr, size, PAGE_SIZE);
dma_addr = dma_addr & PAGE_MASK;
ret = dma_update_trans(zdev, 0, dma_addr, npages * PAGE_SIZE,
ZPCI_PTE_INVALID);
if (ret) {
zpci_err("unmap error:\n");
zpci_err_dma(ret, dma_addr);
return;
}
atomic64_add(npages, &zdev->unmapped_pages);
dma_free_address(dev, dma_addr, npages);
}
static void *s390_dma_alloc(struct device *dev, size_t size,
dma_addr_t *dma_handle, gfp_t flag,
unsigned long attrs)
{
struct zpci_dev *zdev = to_zpci(to_pci_dev(dev));
struct page *page;
unsigned long pa;
dma_addr_t map;
size = PAGE_ALIGN(size);
page = alloc_pages(flag | __GFP_ZERO, get_order(size));
if (!page)
return NULL;
pa = page_to_phys(page);
map = s390_dma_map_pages(dev, page, 0, size, DMA_BIDIRECTIONAL, 0);
if (dma_mapping_error(dev, map)) {
free_pages(pa, get_order(size));
return NULL;
}
atomic64_add(size / PAGE_SIZE, &zdev->allocated_pages);
if (dma_handle)
*dma_handle = map;
return (void *) pa;
}
static void s390_dma_free(struct device *dev, size_t size,
void *pa, dma_addr_t dma_handle,
unsigned long attrs)
{
struct zpci_dev *zdev = to_zpci(to_pci_dev(dev));
size = PAGE_ALIGN(size);
atomic64_sub(size / PAGE_SIZE, &zdev->allocated_pages);
s390_dma_unmap_pages(dev, dma_handle, size, DMA_BIDIRECTIONAL, 0);
free_pages((unsigned long) pa, get_order(size));
}
/* Map a segment into a contiguous dma address area */
static int __s390_dma_map_sg(struct device *dev, struct scatterlist *sg,
size_t size, dma_addr_t *handle,
enum dma_data_direction dir)
{
unsigned long nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;
struct zpci_dev *zdev = to_zpci(to_pci_dev(dev));
dma_addr_t dma_addr_base, dma_addr;
int flags = ZPCI_PTE_VALID;
struct scatterlist *s;
unsigned long pa = 0;
int ret;
dma_addr_base = dma_alloc_address(dev, nr_pages);
if (dma_addr_base == DMA_MAPPING_ERROR)
return -ENOMEM;
dma_addr = dma_addr_base;
if (dir == DMA_NONE || dir == DMA_TO_DEVICE)
flags |= ZPCI_TABLE_PROTECTED;
for (s = sg; dma_addr < dma_addr_base + size; s = sg_next(s)) {
pa = page_to_phys(sg_page(s));
ret = __dma_update_trans(zdev, pa, dma_addr,
s->offset + s->length, flags);
if (ret)
goto unmap;
dma_addr += s->offset + s->length;
}
ret = __dma_purge_tlb(zdev, dma_addr_base, size, flags);
if (ret)
goto unmap;
*handle = dma_addr_base;
atomic64_add(nr_pages, &zdev->mapped_pages);
return ret;
unmap:
dma_update_trans(zdev, 0, dma_addr_base, dma_addr - dma_addr_base,
ZPCI_PTE_INVALID);
dma_free_address(dev, dma_addr_base, nr_pages);
zpci_err("map error:\n");
zpci_err_dma(ret, pa);
return ret;
}
static int s390_dma_map_sg(struct device *dev, struct scatterlist *sg,
int nr_elements, enum dma_data_direction dir,
unsigned long attrs)
{
struct scatterlist *s = sg, *start = sg, *dma = sg;
unsigned int max = dma_get_max_seg_size(dev);
unsigned int size = s->offset + s->length;
unsigned int offset = s->offset;
int count = 0, i;
for (i = 1; i < nr_elements; i++) {
s = sg_next(s);
s->dma_address = DMA_MAPPING_ERROR;
s->dma_length = 0;
if (s->offset || (size & ~PAGE_MASK) ||
size + s->length > max) {
if (__s390_dma_map_sg(dev, start, size,
&dma->dma_address, dir))
goto unmap;
dma->dma_address += offset;
dma->dma_length = size - offset;
size = offset = s->offset;
start = s;
dma = sg_next(dma);
count++;
}
size += s->length;
}
if (__s390_dma_map_sg(dev, start, size, &dma->dma_address, dir))
goto unmap;
dma->dma_address += offset;
dma->dma_length = size - offset;
return count + 1;
unmap:
for_each_sg(sg, s, count, i)
s390_dma_unmap_pages(dev, sg_dma_address(s), sg_dma_len(s),
dir, attrs);
return 0;
}
static void s390_dma_unmap_sg(struct device *dev, struct scatterlist *sg,
int nr_elements, enum dma_data_direction dir,
unsigned long attrs)
{
struct scatterlist *s;
int i;
for_each_sg(sg, s, nr_elements, i) {
if (s->dma_length)
s390_dma_unmap_pages(dev, s->dma_address, s->dma_length,
dir, attrs);
s->dma_address = 0;
s->dma_length = 0;
}
}
int zpci_dma_init_device(struct zpci_dev *zdev)
{
int rc;
/*
* At this point, if the device is part of an IOMMU domain, this would
* be a strong hint towards a bug in the IOMMU API (common) code and/or
* simultaneous access via IOMMU and DMA API. So let's issue a warning.
*/
WARN_ON(zdev->s390_domain);
spin_lock_init(&zdev->iommu_bitmap_lock);
spin_lock_init(&zdev->dma_table_lock);
zdev->dma_table = dma_alloc_cpu_table();
if (!zdev->dma_table) {
rc = -ENOMEM;
goto out;
}
/*
* Restrict the iommu bitmap size to the minimum of the following:
* - main memory size
* - 3-level pagetable address limit minus start_dma offset
* - DMA address range allowed by the hardware (clp query pci fn)
*
* Also set zdev->end_dma to the actual end address of the usable
* range, instead of the theoretical maximum as reported by hardware.
*/
zdev->start_dma = PAGE_ALIGN(zdev->start_dma);
zdev->iommu_size = min3((u64) high_memory,
ZPCI_TABLE_SIZE_RT - zdev->start_dma,
zdev->end_dma - zdev->start_dma + 1);
zdev->end_dma = zdev->start_dma + zdev->iommu_size - 1;
zdev->iommu_pages = zdev->iommu_size >> PAGE_SHIFT;
zdev->iommu_bitmap = vzalloc(zdev->iommu_pages / 8);
if (!zdev->iommu_bitmap) {
rc = -ENOMEM;
goto free_dma_table;
}
if (!s390_iommu_strict) {
zdev->lazy_bitmap = vzalloc(zdev->iommu_pages / 8);
if (!zdev->lazy_bitmap) {
rc = -ENOMEM;
goto free_bitmap;
}
}
rc = zpci_register_ioat(zdev, 0, zdev->start_dma, zdev->end_dma,
(u64) zdev->dma_table);
if (rc)
goto free_bitmap;
return 0;
free_bitmap:
vfree(zdev->iommu_bitmap);
zdev->iommu_bitmap = NULL;
vfree(zdev->lazy_bitmap);
zdev->lazy_bitmap = NULL;
free_dma_table:
dma_free_cpu_table(zdev->dma_table);
zdev->dma_table = NULL;
out:
return rc;
}
void zpci_dma_exit_device(struct zpci_dev *zdev)
{
/*
* At this point, if the device is part of an IOMMU domain, this would
* be a strong hint towards a bug in the IOMMU API (common) code and/or
* simultaneous access via IOMMU and DMA API. So let's issue a warning.
*/
WARN_ON(zdev->s390_domain);
if (zpci_unregister_ioat(zdev, 0))
return;
dma_cleanup_tables(zdev->dma_table);
zdev->dma_table = NULL;
vfree(zdev->iommu_bitmap);
zdev->iommu_bitmap = NULL;
vfree(zdev->lazy_bitmap);
zdev->lazy_bitmap = NULL;
zdev->next_bit = 0;
}
static int __init dma_alloc_cpu_table_caches(void)
{
dma_region_table_cache = kmem_cache_create("PCI_DMA_region_tables",
ZPCI_TABLE_SIZE, ZPCI_TABLE_ALIGN,
0, NULL);
if (!dma_region_table_cache)
return -ENOMEM;
dma_page_table_cache = kmem_cache_create("PCI_DMA_page_tables",
ZPCI_PT_SIZE, ZPCI_PT_ALIGN,
0, NULL);
if (!dma_page_table_cache) {
kmem_cache_destroy(dma_region_table_cache);
return -ENOMEM;
}
return 0;
}
int __init zpci_dma_init(void)
{
return dma_alloc_cpu_table_caches();
}
void zpci_dma_exit(void)
{
kmem_cache_destroy(dma_page_table_cache);
kmem_cache_destroy(dma_region_table_cache);
}
const struct dma_map_ops s390_pci_dma_ops = {
.alloc = s390_dma_alloc,
.free = s390_dma_free,
.map_sg = s390_dma_map_sg,
.unmap_sg = s390_dma_unmap_sg,
.map_page = s390_dma_map_pages,
.unmap_page = s390_dma_unmap_pages,
.mmap = dma_common_mmap,
.get_sgtable = dma_common_get_sgtable,
/* dma_supported is unconditionally true without a callback */
};
EXPORT_SYMBOL_GPL(s390_pci_dma_ops);
static int __init s390_iommu_setup(char *str)
{
if (!strcmp(str, "strict"))
s390_iommu_strict = 1;
return 1;
}
__setup("s390_iommu=", s390_iommu_setup);
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