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gasket_page_table.c
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/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright (C) 2021 Google LLC.
*/
#include "gasket_page_table.h"
#include <linux/dma-buf.h>
#include <linux/file.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/pagemap.h>
#include <linux/version.h>
#include <linux/vmalloc.h>
#include <linux/dma-resv.h>
#if LINUX_VERSION_CODE > KERNEL_VERSION(5, 16, 0)
MODULE_IMPORT_NS(DMA_BUF);
#endif
#include "gasket_logging.h"
#define GASKET_PAGES_PER_SUBTABLE 512
#define GASKET_SIMPLE_PAGE_SHIFT 12
#define GASKET_VALID_SLOT_FLAG 1
#define GASKET_EXTENDED_LVL0_SHIFT 21
#define GASKET_EXTENDED_LVL1_SHIFT 12
#define gasket_pg_tbl_error(pg_tbl,format,arg...) \
gasket_log_error((pg_tbl)->gasket_dev, \
"Page table ID %d: " format, (pg_tbl)->config->id, ##arg)
#define gasket_pg_tbl_warn(pg_tbl,format,arg...) \
gasket_log_warn((pg_tbl)->gasket_dev, \
"Page table ID %d: " format, (pg_tbl)->config->id, ##arg)
#define gasket_pg_tbl_debug(pg_tbl,format,arg...) \
gasket_log_debug((pg_tbl)->gasket_dev, \
"Page table ID %d: " format, (pg_tbl)->config->id, ##arg)
enum pte_status {
PTE_FREE,
PTE_INUSE,
PTE_INUSE_PFN,
PTE_INUSE_SGT,
};
struct gasket_sgt_mapping {
struct sg_table *sgt;
struct dma_buf_attachment *dbuf_attach;
ulong dev_addr;
size_t size;
struct list_head entry;
};
struct gasket_page_table_entry {
enum pte_status status;
dma_addr_t dma_addr;
struct page *page;
uint pfn_num_pages;
struct gasket_page_table_entry *sublevel;
};
struct gasket_page_table {
struct gasket_dev *gasket_dev;
const struct gasket_page_table_config *config;
uint num_simple_entries;
uint num_extended_entries;
struct gasket_page_table_entry *entries;
uint num_active_pages;
u64 __iomem *base_slot;
u64 __iomem *extended_offset_reg;
u64 extended_flag;
struct mutex mutex;
struct list_head sgt_mappings;
};
static int gasket_map_simple_pages(
struct gasket_page_table *pg_tbl, ulong host_addr,
ulong dev_addr, uint num_pages);
static int gasket_map_extended_pages(
struct gasket_page_table *pg_tbl, ulong host_addr,
ulong dev_addr, uint num_pages);
static int gasket_map_sgt_simple_pages(
struct gasket_page_table *pg_tbl, struct gasket_sgt_mapping *mapping);
static int gasket_map_sgt_extended_pages(
struct gasket_page_table *pg_tbl, struct gasket_sgt_mapping *mapping);
static struct gasket_sgt_mapping *gasket_page_table_import_dma_buf(
struct gasket_page_table *pg_tbl, int dma_buf_fd);
static void gasket_page_table_detach_sgt_mapping(
struct gasket_page_table *pg_tbl, struct gasket_sgt_mapping *mapping);
static int gasket_page_table_validate_sgt_mappings(
struct gasket_page_table *pg_tbl, ulong dev_addr, uint num_pages);
static int gasket_page_table_detach_sgt_mappings(
struct gasket_page_table *pg_tbl, ulong dev_addr, uint num_pages);
static size_t gasket_sgt_get_contiguous_size(
struct gasket_page_table *pg_tbl, struct sg_table *sgt);
static int gasket_perform_mapping(
struct gasket_page_table *pg_tbl,
struct gasket_page_table_entry *pte_base, u64 __iomem *att_base,
ulong host_addr, ulong dev_addr, uint num_pages, int is_simple_mapping);
static int gasket_alloc_simple_entries(
struct gasket_page_table *pg_tbl, ulong dev_addr, uint num_pages);
static int gasket_alloc_extended_entries(
struct gasket_page_table *pg_tbl, ulong dev_addr, uint num_entries);
static int gasket_alloc_extended_subtable(struct gasket_page_table *pg_tbl,
struct gasket_page_table_entry *pte, u64 __iomem *att_reg);
static int gasket_page_table_unmap_nolock(
struct gasket_page_table *pg_tbl, ulong start_addr, uint num_pages);
static void gasket_page_table_unmap_all_nolock(
struct gasket_page_table *pg_tbl);
static int gasket_unmap_simple_pages(
struct gasket_page_table *pg_tbl, ulong start_addr, uint num_pages);
static int gasket_unmap_extended_pages(
struct gasket_page_table *pg_tbl, ulong start_addr, uint num_pages,
bool strict);
static int gasket_perform_unmapping(struct gasket_page_table *pg_tbl,
struct gasket_page_table_entry *pte_base, u64 __iomem *att_base,
ulong dev_addr, uint num_pages, int is_simple_mapping,
int *num_unmapped);
static void gasket_free_extended_subtable(struct gasket_page_table *pg_tbl,
struct gasket_page_table_entry *pte, u64 __iomem *att_reg);
static int gasket_release_page(struct page *page);
static inline int gasket_addr_is_simple(
struct gasket_page_table *pg_tbl, ulong addr);
static int gasket_is_simple_dev_addr_bad(
struct gasket_page_table *pg_tbl, ulong dev_addr, uint num_pages);
static int gasket_is_extended_dev_addr_bad(
struct gasket_page_table *pg_tbl, ulong dev_addr, uint num_pages);
static int gasket_is_pte_range_free(
struct gasket_page_table_entry *pte, uint num_entries);
static void gasket_page_table_garbage_collect_nolock(
struct gasket_page_table *pg_tbl);
static ulong gasket_components_to_dev_address(struct gasket_page_table *pg_tbl,
int is_simple, uint page_index, uint offset);
static int gasket_simple_page_idx(
struct gasket_page_table *pg_tbl, ulong dev_addr);
static ulong gasket_extended_lvl0_page_idx(
struct gasket_page_table *pg_tbl, ulong dev_addr);
static ulong gasket_extended_lvl1_page_idx(
struct gasket_page_table *pg_tbl, ulong dev_addr);
#if LINUX_VERSION_CODE < KERNEL_VERSION(6, 1, 0)
struct vm_area_struct * _find_vma(struct vm_area_struct *vma) {
return vma->vm_next;
}
#else
struct vm_area_struct * _find_vma(struct vm_area_struct *vma) {
return find_vma(vma->vm_mm, vma->vm_end);
}
#endif
int gasket_page_table_init(struct gasket_page_table **ppg_tbl,
const struct gasket_bar_data *bar_data,
const struct gasket_page_table_config *page_table_config,
struct gasket_dev *gasket_dev)
{
ulong bytes;
struct gasket_page_table *pg_tbl;
ulong total_entries = page_table_config->total_entries;
if (total_entries == ULONG_MAX) {
gasket_log_error(gasket_dev,
"Error reading page table size. Initializing page table with size 0.");
total_entries = 0;
}
gasket_log_debug(gasket_dev,
"Attempting to initialize page table of size 0x%lx.",
total_entries);
gasket_log_debug(gasket_dev,
"Table has base reg 0x%llx, extended offset reg 0x%llx.",
page_table_config->base_reg,
page_table_config->extended_reg);
*ppg_tbl = kzalloc(sizeof(**ppg_tbl), GFP_KERNEL);
if (!*ppg_tbl) {
gasket_log_error(gasket_dev, "No memory for page tables.");
return -ENOMEM;
}
pg_tbl = *ppg_tbl;
bytes = total_entries * sizeof(struct gasket_page_table_entry);
if (bytes != 0) {
pg_tbl->entries = vmalloc(bytes);
if (!pg_tbl->entries) {
gasket_log_error(gasket_dev,
"No memory for address translation metadata.");
kfree(pg_tbl);
*ppg_tbl = NULL;
return -ENOMEM;
}
memset(pg_tbl->entries, 0, bytes);
}
mutex_init(&pg_tbl->mutex);
pg_tbl->config = page_table_config;
if (pg_tbl->config->mode == GASKET_PAGE_TABLE_MODE_NORMAL ||
pg_tbl->config->mode == GASKET_PAGE_TABLE_MODE_SIMPLE) {
pg_tbl->num_simple_entries = total_entries;
pg_tbl->num_extended_entries = 0;
pg_tbl->extended_flag = 1ull << page_table_config->extended_bit;
} else {
pg_tbl->num_simple_entries = 0;
pg_tbl->num_extended_entries = total_entries;
pg_tbl->extended_flag = 0;
}
pg_tbl->num_active_pages = 0;
pg_tbl->base_slot = (u64 __iomem *)&(
bar_data->virt_base[page_table_config->base_reg]);
pg_tbl->extended_offset_reg = (u64 __iomem *)&(
bar_data->virt_base[page_table_config->extended_reg]);
pg_tbl->gasket_dev = gasket_dev;
INIT_LIST_HEAD(&pg_tbl->sgt_mappings);
gasket_log_debug(gasket_dev, "Page table initialized successfully.");
return 0;
}
void gasket_page_table_cleanup(struct gasket_page_table *pg_tbl)
{
gasket_page_table_garbage_collect(pg_tbl);
vfree(pg_tbl->entries);
pg_tbl->entries = NULL;
kfree(pg_tbl);
}
int gasket_page_table_partition(
struct gasket_page_table *pg_tbl, uint num_simple_entries)
{
int i, start;
mutex_lock(&pg_tbl->mutex);
if (pg_tbl->config->mode != GASKET_PAGE_TABLE_MODE_NORMAL) {
gasket_pg_tbl_error(
pg_tbl, "This page table is not configurable!");
return -EINVAL;
}
if (num_simple_entries > pg_tbl->config->total_entries) {
mutex_unlock(&pg_tbl->mutex);
return -EINVAL;
}
gasket_page_table_garbage_collect_nolock(pg_tbl);
start = min(pg_tbl->num_simple_entries, num_simple_entries);
for (i = start; i < pg_tbl->config->total_entries; i++) {
if (pg_tbl->entries[i].status != PTE_FREE) {
gasket_pg_tbl_error(pg_tbl, "entry %d is not free", i);
mutex_unlock(&pg_tbl->mutex);
return -EBUSY;
}
}
pg_tbl->num_simple_entries = num_simple_entries;
pg_tbl->num_extended_entries =
pg_tbl->config->total_entries - num_simple_entries;
writeq(num_simple_entries, pg_tbl->extended_offset_reg);
mutex_unlock(&pg_tbl->mutex);
return 0;
}
EXPORT_SYMBOL(gasket_page_table_partition);
int gasket_page_table_dma_buf_map(
struct gasket_page_table *pg_tbl, int dma_buf_fd, ulong dev_addr)
{
int ret;
uint num_pages;
struct gasket_sgt_mapping *mapping;
struct dma_buf *dbuf;
mapping = gasket_page_table_import_dma_buf(pg_tbl, dma_buf_fd);
if (IS_ERR(mapping))
return PTR_ERR(mapping);
mutex_lock(&pg_tbl->mutex);
INIT_LIST_HEAD(&mapping->entry);
mapping->dev_addr = dev_addr;
dbuf = mapping->dbuf_attach->dmabuf;
if (mapping->size !=
gasket_sgt_get_contiguous_size(pg_tbl, mapping->sgt)) {
gasket_pg_tbl_error(
pg_tbl, "failed to map non-contiguous scatterlist");
ret = -EINVAL;
goto dma_buf_map_failed;
}
num_pages = mapping->size >> PAGE_SHIFT;
if (gasket_page_table_is_dev_addr_bad(
pg_tbl, dev_addr, mapping->size)) {
ret = -EINVAL;
goto dma_buf_map_failed;
}
if (gasket_addr_is_simple(pg_tbl, dev_addr))
ret = gasket_map_sgt_simple_pages(pg_tbl, mapping);
else
ret = gasket_map_sgt_extended_pages(pg_tbl, mapping);
if (ret) {
gasket_pg_tbl_error(pg_tbl, "failed to map dma_buf: %d", ret);
goto dma_buf_map_failed;
}
list_add_tail(&mapping->entry, &pg_tbl->sgt_mappings);
mutex_unlock(&pg_tbl->mutex);
return ret;
dma_buf_map_failed:
gasket_page_table_detach_sgt_mapping(pg_tbl, mapping);
mutex_unlock(&pg_tbl->mutex);
return ret;
}
EXPORT_SYMBOL(gasket_page_table_dma_buf_map);
int gasket_page_table_map(struct gasket_page_table *pg_tbl, ulong host_addr,
ulong dev_addr, ulong bytes)
{
int ret = 0;
uint num_pages;
mutex_lock(&pg_tbl->mutex);
if (gasket_page_table_are_addrs_bad(pg_tbl, host_addr, dev_addr,
bytes)) {
ret = -EINVAL;
} else {
num_pages = bytes / PAGE_SIZE;
if (gasket_addr_is_simple(pg_tbl, dev_addr)) {
ret = gasket_map_simple_pages(
pg_tbl, host_addr, dev_addr, num_pages);
} else {
ret = gasket_map_extended_pages(
pg_tbl, host_addr, dev_addr, num_pages);
}
}
mutex_unlock(&pg_tbl->mutex);
return ret;
}
EXPORT_SYMBOL(gasket_page_table_map);
int gasket_page_table_unmap(
struct gasket_page_table *pg_tbl, ulong dev_addr, ulong bytes)
{
int ret = 0;
uint num_pages;
mutex_lock(&pg_tbl->mutex);
if (gasket_page_table_is_dev_addr_bad(pg_tbl, dev_addr, bytes)) {
ret = -EINVAL;
} else {
num_pages = bytes / PAGE_SIZE;
ret = gasket_page_table_unmap_nolock(pg_tbl, dev_addr,
num_pages);
}
mutex_unlock(&pg_tbl->mutex);
return ret;
}
EXPORT_SYMBOL(gasket_page_table_unmap);
static void gasket_page_table_unmap_all_nolock(struct gasket_page_table *pg_tbl)
{
WARN_ON(gasket_unmap_simple_pages(pg_tbl,
gasket_components_to_dev_address(pg_tbl, 1, 0, 0),
pg_tbl->num_simple_entries));
WARN_ON(gasket_unmap_extended_pages(pg_tbl,
gasket_components_to_dev_address(pg_tbl, 0, 0, 0),
pg_tbl->num_extended_entries * GASKET_PAGES_PER_SUBTABLE,
false));
}
void gasket_page_table_unmap_all(struct gasket_page_table *pg_tbl)
{
mutex_lock(&pg_tbl->mutex);
gasket_page_table_unmap_all_nolock(pg_tbl);
mutex_unlock(&pg_tbl->mutex);
}
EXPORT_SYMBOL(gasket_page_table_unmap_all);
void gasket_page_table_reset(struct gasket_page_table *pg_tbl)
{
mutex_lock(&pg_tbl->mutex);
gasket_page_table_unmap_all_nolock(pg_tbl);
if (pg_tbl->config->mode == GASKET_PAGE_TABLE_MODE_NORMAL)
writeq(pg_tbl->config->total_entries,
pg_tbl->extended_offset_reg);
mutex_unlock(&pg_tbl->mutex);
}
void gasket_page_table_garbage_collect(struct gasket_page_table *pg_tbl)
{
mutex_lock(&pg_tbl->mutex);
gasket_page_table_garbage_collect_nolock(pg_tbl);
mutex_unlock(&pg_tbl->mutex);
}
EXPORT_SYMBOL(gasket_page_table_garbage_collect);
int gasket_page_table_are_addrs_bad(struct gasket_page_table *pg_tbl,
ulong host_addr, ulong dev_addr, ulong bytes)
{
struct vm_area_struct *vma;
ulong current_ptr = host_addr;
ulong end_ptr = host_addr + bytes;
ulong required_perms = VM_READ | VM_WRITE;
if (host_addr & (PAGE_SIZE - 1)) {
gasket_pg_tbl_error(pg_tbl,
"host mapping address 0x%lx must be page aligned",
host_addr);
return 1;
}
down_read(¤t->mm->mmap_lock);
vma = find_vma(current->mm, current_ptr);
if (unlikely(!vma)) {
gasket_pg_tbl_error(pg_tbl,
"No VMA found that satisfies 0x%lx < vm_end",
current_ptr);
goto fail;
}
while (current_ptr < end_ptr) {
if (vma->vm_start > current_ptr || vma->vm_end <= current_ptr) {
gasket_pg_tbl_error(pg_tbl,
"Found VMA [0x%lx, 0x%lx) does not include the host VM address: 0x%lx",
vma->vm_start, vma->vm_end, current_ptr);
goto fail;
}
if ((vma->vm_flags & required_perms) != required_perms) {
gasket_pg_tbl_error(pg_tbl,
"Process must have read/write perms (0x%lx) to map address 0x%lx into device (VMA: [0x%lx, 0x%lx), flags: 0x%lx)",
required_perms, current_ptr, vma->vm_flags,
vma->vm_start, vma->vm_end);
goto fail;
}
if ((vma->vm_flags & VM_DONTCOPY) != VM_DONTCOPY) {
gasket_pg_tbl_warn(pg_tbl,
"Mapping VMA [0x%lx, 0x%lx) that does not have VM_DONTCOPY set. This may lead to memory corruption after fork.",
vma->vm_start, vma->vm_end);
gasket_mapped_unforkable_page(pg_tbl->gasket_dev);
}
if (end_ptr <= vma->vm_end)
break;
current_ptr = vma->vm_end;
vma = _find_vma(vma);
if (!vma) {
gasket_pg_tbl_error(pg_tbl,
"No more VMAs after [0x%lx, 0x%lx) to search through",
vma->vm_start, vma->vm_end);
goto fail;
}
}
up_read(¤t->mm->mmap_lock);
return gasket_page_table_is_dev_addr_bad(pg_tbl, dev_addr, bytes);
fail:
up_read(¤t->mm->mmap_lock);
gasket_pg_tbl_error(pg_tbl,
"Failure while checking host range [0x%lx, 0x%lx)", host_addr,
host_addr + bytes);
return -EFAULT;
}
EXPORT_SYMBOL(gasket_page_table_are_addrs_bad);
int gasket_page_table_is_dev_addr_bad(
struct gasket_page_table *pg_tbl, ulong dev_addr, ulong bytes)
{
uint num_pages = bytes / PAGE_SIZE;
if (bytes & (PAGE_SIZE - 1)) {
gasket_pg_tbl_error(pg_tbl,
"mapping size 0x%lX must be page aligned", bytes);
return 1;
}
if (num_pages == 0) {
gasket_pg_tbl_error(pg_tbl,
"requested mapping is less than one page: %lu / %lu",
bytes, PAGE_SIZE);
return 1;
}
if (gasket_addr_is_simple(pg_tbl, dev_addr))
return gasket_is_simple_dev_addr_bad(
pg_tbl, dev_addr, num_pages);
else
return gasket_is_extended_dev_addr_bad(
pg_tbl, dev_addr, num_pages);
}
EXPORT_SYMBOL(gasket_page_table_is_dev_addr_bad);
uint gasket_page_table_max_size(struct gasket_page_table *pg_tbl)
{
if (unlikely(!pg_tbl)) {
gasket_nodev_error("Passed a null page table.");
return 0;
}
return pg_tbl->config->total_entries;
}
EXPORT_SYMBOL(gasket_page_table_max_size);
uint gasket_page_table_num_entries(struct gasket_page_table *pg_tbl)
{
if (unlikely(!pg_tbl)) {
gasket_nodev_error("Passed a null page table.");
return 0;
}
return pg_tbl->num_simple_entries + pg_tbl->num_extended_entries;
}
EXPORT_SYMBOL(gasket_page_table_num_entries);
uint gasket_page_table_num_simple_entries(struct gasket_page_table *pg_tbl)
{
if (unlikely(!pg_tbl)) {
gasket_nodev_error("Passed a null page table.");
return 0;
}
return pg_tbl->num_simple_entries;
}
EXPORT_SYMBOL(gasket_page_table_num_simple_entries);
uint gasket_page_table_num_extended_entries(struct gasket_page_table *pg_tbl)
{
if (unlikely(!pg_tbl)) {
gasket_nodev_error("Passed a null page table.");
return 0;
}
return pg_tbl->num_extended_entries;
}
EXPORT_SYMBOL(gasket_page_table_num_extended_entries);
uint gasket_page_table_num_active_pages(struct gasket_page_table *pg_tbl)
{
if (unlikely(!pg_tbl)) {
gasket_nodev_error("Passed a null page table.");
return 0;
}
return pg_tbl->num_active_pages;
}
EXPORT_SYMBOL(gasket_page_table_num_active_pages);
int gasket_page_table_system_status(struct gasket_page_table *pg_tbl)
{
if (unlikely(!pg_tbl)) {
gasket_nodev_error("Passed a null page table.");
return GASKET_STATUS_LAMED;
}
if (gasket_page_table_num_entries(pg_tbl) == 0) {
gasket_log_error(pg_tbl->gasket_dev,
"Page table size is 0.");
return GASKET_STATUS_LAMED;
}
return GASKET_STATUS_ALIVE;
}
static int gasket_map_simple_pages(struct gasket_page_table *pg_tbl,
ulong host_addr, ulong dev_addr, uint num_pages)
{
int ret;
uint slot_idx = gasket_simple_page_idx(pg_tbl, dev_addr);
ret = gasket_alloc_simple_entries(pg_tbl, dev_addr, num_pages);
if (ret) {
gasket_pg_tbl_error(pg_tbl,
"page table slots %u (@ 0x%lx) to %u are not available",
slot_idx, dev_addr, slot_idx + num_pages - 1);
return ret;
}
ret = gasket_perform_mapping(pg_tbl, pg_tbl->entries + slot_idx,
pg_tbl->base_slot + slot_idx, host_addr, dev_addr, num_pages,
1);
if (ret)
gasket_page_table_unmap_nolock(pg_tbl, dev_addr, num_pages);
return ret;
}
static int gasket_map_extended_pages(
struct gasket_page_table *pg_tbl, ulong host_addr,
ulong dev_addr, uint num_pages)
{
int ret;
ulong dev_addr_start = dev_addr;
ulong dev_addr_end;
uint slot_idx, remain, len;
struct gasket_page_table_entry *pte;
u64 __iomem *slot_base;
ret = gasket_alloc_extended_entries(pg_tbl, dev_addr, num_pages);
if (ret) {
dev_addr_end = dev_addr + (num_pages / PAGE_SIZE) - 1;
gasket_pg_tbl_error(pg_tbl,
"page table slots (%lu,%lu) (@ 0x%lx) to (%lu,%lu) are not available",
gasket_extended_lvl0_page_idx(pg_tbl, dev_addr),
gasket_extended_lvl1_page_idx(pg_tbl, dev_addr),
dev_addr,
gasket_extended_lvl0_page_idx(pg_tbl, dev_addr_end),
gasket_extended_lvl1_page_idx(pg_tbl, dev_addr_end));
return ret;
}
remain = num_pages;
slot_idx = gasket_extended_lvl1_page_idx(pg_tbl, dev_addr);
pte = pg_tbl->entries + pg_tbl->num_simple_entries +
gasket_extended_lvl0_page_idx(pg_tbl, dev_addr);
while (remain > 0) {
len = min(remain, GASKET_PAGES_PER_SUBTABLE - slot_idx);
slot_base =
(u64 __iomem *)(page_address(pte->page));
ret = gasket_perform_mapping(pg_tbl, pte->sublevel + slot_idx,
slot_base + slot_idx, host_addr, dev_addr, len, 0);
if (ret) {
gasket_page_table_unmap_nolock(
pg_tbl, dev_addr_start, num_pages - remain);
return ret;
}
remain -= len;
slot_idx = 0;
pte++;
host_addr += len * PAGE_SIZE;
dev_addr += len * PAGE_SIZE;
}
return 0;
}
static bool use_hpa_for_pfn_mappings(struct pci_dev *dev, ulong host_addr,
ulong size)
{
return false;
}
static int perform_pfn_mapping(struct gasket_page_table *pg_tbl,
struct gasket_page_table_entry *ptes, u64 __iomem *slots,
ulong host_addr, ulong dev_addr, uint num_pages, int is_simple_mapping)
{
int ret = 0;
int i;
struct vm_area_struct *vma;
const size_t size = (size_t)num_pages << PAGE_SHIFT;
unsigned long vma_offset;
bool always_use_hpa = false;
phys_addr_t host_phys_addr;
dma_addr_t host_dma_addr = 0;
dma_addr_t page_dma_addr;
dma_addr_t device_dma_addr;
down_read(¤t->mm->mmap_lock);
vma = find_vma(current->mm, host_addr);
if (vma == NULL) {
ret = -EFAULT;
goto error_mm;
}
if (!(vma->vm_flags & VM_PFNMAP)) {
gasket_pg_tbl_error(pg_tbl,
"VMA region is not VM_PFNMAP: host_addr=%#lx, size=%#lx, vm_flags=%#lx, vm_pgoff=%#lx",
host_addr, size, vma->vm_flags, vma->vm_pgoff);
ret = -EINVAL;
goto error_mm;
}
if (host_addr + size > vma->vm_end) {
gasket_pg_tbl_error(pg_tbl,
"VMA region does not cover the requested range: host_addr=%#lx, size=%#lx, vm_start=%#lx, vm_end=%#lx, vm_pgoff=%#lx",
host_addr, size, vma->vm_start, vma->vm_end,
vma->vm_pgoff);
ret = -EINVAL;
goto error_mm;
}
vma_offset = host_addr - vma->vm_start;
host_phys_addr = (vma->vm_pgoff << PAGE_SHIFT) + vma_offset;
up_read(¤t->mm->mmap_lock);
gasket_pg_tbl_debug(pg_tbl,
"%s: virt_addr_valid=%d, host_phys_addr=%#llx, iommu_ops=%p\n",
__func__, virt_addr_valid(host_phys_addr), host_phys_addr,
pg_tbl->gasket_dev->pci_dev->dev.bus->iommu_ops);
always_use_hpa = use_hpa_for_pfn_mappings(pg_tbl->gasket_dev->pci_dev,
host_phys_addr, size);
if (gasket_pci_is_iommu_enabled(pg_tbl->gasket_dev->pci_dev) &&
!always_use_hpa) {
ret = dma_mapping_error(
&pg_tbl->gasket_dev->pci_dev->dev, host_dma_addr);
if (ret) {
gasket_pg_tbl_error(pg_tbl,
"Error allocating IOVA for PFN region for DMA: %d",
ret);
return ret;
}
ret = dma_mapping_error(
&pg_tbl->gasket_dev->pci_dev->dev, page_dma_addr);
if (ret) {
gasket_pg_tbl_error(pg_tbl,
"Error mapping IOVA to PFN region for DMA: %d",
ret);
goto error;
}
WARN_ON(host_dma_addr != page_dma_addr);
} else {
#ifdef CONFIG_VIRT_TO_BUS
ret = 0;
host_dma_addr = virt_to_bus(phys_to_virt(host_phys_addr));
#else
gasket_pg_tbl_error(pg_tbl,
"Mapping PFN regions for DMA is not supported");
return -EINVAL;
#endif
}
if (pg_tbl->config->map_buffer_cb) {
ret = pg_tbl->config->map_buffer_cb(
pg_tbl->gasket_dev, pg_tbl->config->id,
host_dma_addr, dev_addr, num_pages);
if (ret) {
gasket_pg_tbl_error(pg_tbl,
"Map buffer callback error for dev_addr=%#lx, host_addr=%#lx, host_dma_addr=%#llx, size=%#lx: %d",
dev_addr, host_addr, host_dma_addr, size, ret);
goto error;
}
}
gasket_pg_tbl_debug(pg_tbl,
"Mapped VMA region: dev_addr=%#lx, host_addr=%#lx, size=%#lx, vm_start=%#lx, vm_end=%#lx, vm_pgoff=%#lx, host_ptr=%#llx, dma_addr=%#llx",
dev_addr, host_addr, size, vma->vm_start, vma->vm_end,
vma->vm_pgoff, host_phys_addr, host_dma_addr);
ptes[0].pfn_num_pages = num_pages;
page_dma_addr = host_dma_addr;
for (i = 0; i < num_pages; ++i, page_dma_addr += PAGE_SIZE) {
ptes[i].dma_addr = page_dma_addr;
device_dma_addr = page_dma_addr | GASKET_VALID_SLOT_FLAG;
if (is_simple_mapping)
writeq(device_dma_addr, &slots[i]);
else
((u64 __force *)slots)[i] = device_dma_addr;
ptes[i].status = PTE_INUSE_PFN;
}
pg_tbl->num_active_pages += num_pages;
return 0;
error:
if (gasket_pci_is_iommu_enabled(pg_tbl->gasket_dev->pci_dev) &&
host_dma_addr && !always_use_hpa) {}
return ret;
error_mm:
up_read(¤t->mm->mmap_lock);
return ret;
}
static int gasket_perform_mapping(struct gasket_page_table *pg_tbl,
struct gasket_page_table_entry *ptes, u64 __iomem *slots,
ulong host_addr, ulong dev_addr, uint num_pages, int is_simple_mapping)
{
struct device *dev = &pg_tbl->gasket_dev->pci_dev->dev;
int i, ret, num_dma_mapped = 0;
uint pages_to_free = 0;
dma_addr_t dma_addr;
ulong page_addr;
struct page **pages;
if (num_pages == 0)
return 0;
if (host_addr & (PAGE_SIZE - 1)) {
gasket_pg_tbl_error(pg_tbl,
"host address 0x%lx is not page-aligned (this should never get here)!",
host_addr);
return -EINVAL;
}
pages = kmalloc_array(num_pages, sizeof(struct page *), GFP_KERNEL);
if (!pages)
return -ENOMEM;
ret = get_user_pages_fast(host_addr, num_pages, 1, pages);
if (ret == -EFAULT) {
ret = perform_pfn_mapping(pg_tbl, ptes, slots, host_addr,
dev_addr, num_pages,
is_simple_mapping);
goto exit;
}
if (ret != num_pages) {
gasket_pg_tbl_error(pg_tbl,
"Failed to map buffer: host_addr=%#lx, ret=%d, num_pages=%d",
host_addr, ret, num_pages);
if (ret >= 0) {
pages_to_free = ret;
ret = -ENOMEM;
}
goto fail;
}
pg_tbl->num_active_pages += num_pages;
pages_to_free = num_pages;
for (i = 0; i < num_pages; i++) {
page_addr = host_addr + i * PAGE_SIZE;
ptes[i].page = pages[i];
ptes[i].dma_addr = dma_map_page(dev,
pages[i], 0, PAGE_SIZE, DMA_BIDIRECTIONAL);
ret = dma_mapping_error(dev, ptes[i].dma_addr);
if (ret) {
gasket_pg_tbl_error(pg_tbl,
"Error mapping page for DMA: %d", ret);
ret = -EFAULT;
goto fail;
}
num_dma_mapped++;
mb();
if (pg_tbl->config->map_buffer_cb) {
ret = pg_tbl->config->map_buffer_cb(
pg_tbl->gasket_dev, pg_tbl->config->id,
ptes[i].dma_addr, dev_addr, 1);
if (ret) {
gasket_pg_tbl_error(pg_tbl,
"Map buffer callback error for dev_addr=%#lx: %d",
dev_addr, ret);
goto fail;
}
dev_addr += PAGE_SIZE;
}
dma_addr = (ptes[i].dma_addr) | GASKET_VALID_SLOT_FLAG;
if (is_simple_mapping)
writeq(dma_addr, &slots[i]);
else
((u64 __force *)slots)[i] = dma_addr;
ptes[i].status = PTE_INUSE;
}
ret = 0;
goto exit;
fail:
for (i = 0; i < pages_to_free; i++) {
if (i < num_dma_mapped) {
dma_unmap_page(dev, ptes[i].dma_addr, PAGE_SIZE,
DMA_BIDIRECTIONAL);
}
gasket_release_page(pages[i]);
ptes[i].status = PTE_FREE;
}
exit:
kfree(pages);
return ret;
}
static int gasket_alloc_simple_entries(
struct gasket_page_table *pg_tbl, ulong dev_addr, uint num_pages)
{
if (!gasket_is_pte_range_free(
pg_tbl->entries + gasket_simple_page_idx(pg_tbl, dev_addr),
num_pages))
return -EBUSY;
return 0;
}
static int gasket_alloc_extended_entries(
struct gasket_page_table *pg_tbl, ulong dev_addr, uint num_entries)
{
int ret = 0;
uint remain, subtable_slot_idx, len;
struct gasket_page_table_entry *pte;
u64 __iomem *slot;
remain = num_entries;
subtable_slot_idx = gasket_extended_lvl1_page_idx(pg_tbl, dev_addr);
pte = pg_tbl->entries + pg_tbl->num_simple_entries +
gasket_extended_lvl0_page_idx(pg_tbl, dev_addr);
slot = pg_tbl->base_slot + pg_tbl->num_simple_entries +
gasket_extended_lvl0_page_idx(pg_tbl, dev_addr);
while (remain > 0) {
len = min(remain,
GASKET_PAGES_PER_SUBTABLE - subtable_slot_idx);
if (pte->status == PTE_FREE) {
ret = gasket_alloc_extended_subtable(pg_tbl, pte, slot);
if (ret) {
gasket_pg_tbl_error(pg_tbl,
"no memory for extended addr subtable");
return ret;
}
} else {
if (!gasket_is_pte_range_free(
pte->sublevel + subtable_slot_idx, len))
return -EBUSY;
}
remain -= len;
subtable_slot_idx = 0;
pte++;
slot++;
}
return 0;
}
static int gasket_alloc_extended_subtable(struct gasket_page_table *pg_tbl,
struct gasket_page_table_entry *pte, u64 __iomem *slot)
{
struct device *dev = &pg_tbl->gasket_dev->pci_dev->dev;
ulong page_addr, subtable_bytes;
dma_addr_t dma_addr;
page_addr = get_zeroed_page(GFP_KERNEL);
if (!page_addr)
return -ENOMEM;
pte->page = virt_to_page((void *)page_addr);
subtable_bytes = sizeof(struct gasket_page_table_entry) *
GASKET_PAGES_PER_SUBTABLE;
pte->sublevel = vmalloc(subtable_bytes);
if (!pte->sublevel)
goto fail_subtable_allocate;
memset(pte->sublevel, 0, subtable_bytes);
pte->dma_addr = dma_map_page(dev, pte->page, 0, PAGE_SIZE,
DMA_BIDIRECTIONAL);
if (unlikely(dma_mapping_error(dev, pte->dma_addr)))
goto fail_dma_map;
mb();
dma_addr = pte->dma_addr | GASKET_VALID_SLOT_FLAG;
writeq(dma_addr, slot);
pte->status = PTE_INUSE;
return 0;
fail_dma_map:
vfree(pte->sublevel);
fail_subtable_allocate:
free_page(page_addr);
memset(pte, 0, sizeof(struct gasket_page_table_entry));
return -ENOMEM;
}
static int gasket_page_table_unmap_nolock(
struct gasket_page_table *pg_tbl, ulong dev_addr, uint num_pages)
{
if (!num_pages)
return 0;
if (gasket_addr_is_simple(pg_tbl, dev_addr))
return gasket_unmap_simple_pages(pg_tbl, dev_addr, num_pages);
else
return gasket_unmap_extended_pages(
pg_tbl, dev_addr, num_pages, true);
}
static int gasket_unmap_simple_pages(
struct gasket_page_table *pg_tbl, ulong dev_addr, uint num_pages)
{
int ret;
uint slot = gasket_simple_page_idx(pg_tbl, dev_addr);
ret = gasket_page_table_validate_sgt_mappings(
pg_tbl, dev_addr, num_pages);
if (ret) {
gasket_pg_tbl_error(pg_tbl,
"Partial unmapping of scatterlist is not allowed: %d",
ret);
return ret;
}
ret = gasket_perform_unmapping(pg_tbl, pg_tbl->entries + slot,
pg_tbl->base_slot + slot, dev_addr, num_pages, 1, NULL);
if (ret)
return ret;
gasket_page_table_detach_sgt_mappings(pg_tbl, dev_addr, num_pages);
return ret;
}
static void perform_sgt_dma_addr_mapping(struct gasket_page_table *pg_tbl,
struct gasket_page_table_entry *ptes, u64 __iomem *slots,
dma_addr_t dma_addr, uint num_pages, int is_simple_mapping)
{
int i;
dma_addr_t page_dma_addr;
dma_addr_t device_dma_addr;
gasket_pg_tbl_debug(pg_tbl, "Mapping dma_addr=%#llx, iommu_ops=%p\n",
dma_addr, pg_tbl->gasket_dev->pci_dev->dev.bus->iommu_ops);
page_dma_addr = dma_addr;
for (i = 0; i < num_pages; ++i, page_dma_addr += PAGE_SIZE) {
ptes[i].dma_addr = page_dma_addr;
device_dma_addr = page_dma_addr | GASKET_VALID_SLOT_FLAG;
if (is_simple_mapping)
writeq(device_dma_addr, &slots[i]);
else
((u64 __force *)slots)[i] = device_dma_addr;
ptes[i].status = PTE_INUSE_SGT;
}
pg_tbl->num_active_pages += num_pages;
}
static size_t gasket_sgt_get_contiguous_size(
struct gasket_page_table *pg_tbl, struct sg_table *sgt)
{
int i;
size_t sz = 0;
dma_addr_t start;
struct scatterlist *sg;
start = sg_dma_address(sgt->sgl);
for_each_sg(sgt->sgl, sg, sgt->nents, i) {
if (!IS_ALIGNED(sg_dma_address(sg), PAGE_SIZE) ||
!IS_ALIGNED(sg_dma_len(sg), PAGE_SIZE)) {
gasket_pg_tbl_error(pg_tbl,
"Entry in sg_table is not page aligned: dma_address: 0x%llx size: 0x%x",
sg_dma_address(sg), sg->length);
break;
}
if (sg_dma_address(sg) != start) {
break;
}
start += sg_dma_len(sg);
sz += sg_dma_len(sg);
}
return sz;
}
static void gasket_page_table_dma_buf_move_notify(
struct dma_buf_attachment *attachment)
{
struct gasket_sgt_mapping *mapping;
struct gasket_page_table *pg_tbl;
pg_tbl = attachment->importer_priv;
if (!pg_tbl) {
gasket_pg_tbl_warn(pg_tbl,
"dma_buf move notify received with invalid pg_tbl.");
return;
}
mutex_lock(&pg_tbl->mutex);
list_for_each_entry(mapping, &pg_tbl->sgt_mappings, entry) {
if (mapping->dbuf_attach == attachment) {
gasket_pg_tbl_warn(pg_tbl,
"dma_buf attachment moved: %p", attachment);
break;
}
}
mutex_unlock(&pg_tbl->mutex);
}
static const struct dma_buf_attach_ops gasket_dma_buf_attach_ops = {
.allow_peer2peer = true,
.move_notify = gasket_page_table_dma_buf_move_notify,
};
static struct gasket_sgt_mapping *gasket_page_table_import_dma_buf(
struct gasket_page_table *pg_tbl, int dma_buf_fd)
{
int ret;
struct gasket_dev *gasket_dev;
struct gasket_sgt_mapping *mapping;
struct dma_buf *dbuf;
gasket_dev = pg_tbl->gasket_dev;
dbuf = dma_buf_get(dma_buf_fd);
if (IS_ERR(dbuf)) {
ret = PTR_ERR(dbuf);
gasket_log_error(gasket_dev,
"failed to get dma_buf using filedescriptor: %d", ret);
return ERR_PTR(ret);
}
if (dbuf->size == 0) {
gasket_log_error(
gasket_dev, "Cannot import dma_buf with zero size");
ret = -EINVAL;
goto failed_mapping_alloc;
}
ret = 0;
mapping = kzalloc(sizeof(*mapping), GFP_KERNEL);
if (!mapping) {
gasket_log_error(gasket_dev,
"failed to allocate memory for mapping struct");
ret = -ENOMEM;
goto failed_mapping_alloc;
}
mapping->dbuf_attach = dma_buf_dynamic_attach(dbuf,
&gasket_dev->pci_dev->dev, &gasket_dma_buf_attach_ops, pg_tbl);
if (IS_ERR(mapping->dbuf_attach)) {
ret = PTR_ERR(mapping->dbuf_attach);
gasket_log_error(
gasket_dev, "failed to attach to the dma_buf: %d", ret);
goto failed_attach;
}
mapping->size = dbuf->size;
dma_resv_lock(dbuf->resv, NULL);
mapping->sgt =
dma_buf_map_attachment(mapping->dbuf_attach, DMA_BIDIRECTIONAL);
dma_resv_unlock(dbuf->resv);
if (IS_ERR(mapping->sgt)) {
ret = PTR_ERR(mapping->sgt);
gasket_log_error(gasket_dev,
"failed to map dma_buf attachment: %d", ret);
goto failed_map;
}
return mapping;
failed_map:
dma_buf_detach(dbuf, mapping->dbuf_attach);
failed_attach:
kfree(mapping);
failed_mapping_alloc:
dma_buf_put(dbuf);
return ERR_PTR(ret);
}
static void gasket_page_table_detach_sgt_mapping(
struct gasket_page_table *pg_tbl, struct gasket_sgt_mapping *mapping)
{