mirror of
https://github.com/torvalds/linux.git
synced 2024-11-22 04:38:03 +00:00
17b226dcf8
This will be useful for GPU drivers who want to keep page tables in a pool so they can: - keep freed page tables in a free pool and speed-up upcoming page table allocations - batch page table allocation instead of allocating one page at a time - pre-reserve pages for page tables needed for map/unmap operations, to ensure map/unmap operations don't try to allocate memory in paths they're allowed to block or fail It might also be valuable for other aspects of GPU and similar use-cases, like fine-grained memory accounting and resource limiting. We will extend the Arm LPAE format to support custom allocators in a separate commit. Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com> Reviewed-by: Steven Price <steven.price@arm.com> Reviewed-by: Robin Murphy <robin.murphy@arm.com> Link: https://lore.kernel.org/r/20231124142434.1577550-2-boris.brezillon@collabora.com Signed-off-by: Joerg Roedel <jroedel@suse.de>
102 lines
2.5 KiB
C
102 lines
2.5 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/*
|
|
* Generic page table allocator for IOMMUs.
|
|
*
|
|
* Copyright (C) 2014 ARM Limited
|
|
*
|
|
* Author: Will Deacon <will.deacon@arm.com>
|
|
*/
|
|
|
|
#include <linux/bug.h>
|
|
#include <linux/io-pgtable.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/types.h>
|
|
|
|
static const struct io_pgtable_init_fns *
|
|
io_pgtable_init_table[IO_PGTABLE_NUM_FMTS] = {
|
|
#ifdef CONFIG_IOMMU_IO_PGTABLE_LPAE
|
|
[ARM_32_LPAE_S1] = &io_pgtable_arm_32_lpae_s1_init_fns,
|
|
[ARM_32_LPAE_S2] = &io_pgtable_arm_32_lpae_s2_init_fns,
|
|
[ARM_64_LPAE_S1] = &io_pgtable_arm_64_lpae_s1_init_fns,
|
|
[ARM_64_LPAE_S2] = &io_pgtable_arm_64_lpae_s2_init_fns,
|
|
[ARM_MALI_LPAE] = &io_pgtable_arm_mali_lpae_init_fns,
|
|
#endif
|
|
#ifdef CONFIG_IOMMU_IO_PGTABLE_DART
|
|
[APPLE_DART] = &io_pgtable_apple_dart_init_fns,
|
|
[APPLE_DART2] = &io_pgtable_apple_dart_init_fns,
|
|
#endif
|
|
#ifdef CONFIG_IOMMU_IO_PGTABLE_ARMV7S
|
|
[ARM_V7S] = &io_pgtable_arm_v7s_init_fns,
|
|
#endif
|
|
#ifdef CONFIG_AMD_IOMMU
|
|
[AMD_IOMMU_V1] = &io_pgtable_amd_iommu_v1_init_fns,
|
|
[AMD_IOMMU_V2] = &io_pgtable_amd_iommu_v2_init_fns,
|
|
#endif
|
|
};
|
|
|
|
static int check_custom_allocator(enum io_pgtable_fmt fmt,
|
|
struct io_pgtable_cfg *cfg)
|
|
{
|
|
/* No custom allocator, no need to check the format. */
|
|
if (!cfg->alloc && !cfg->free)
|
|
return 0;
|
|
|
|
/* When passing a custom allocator, both the alloc and free
|
|
* functions should be provided.
|
|
*/
|
|
if (!cfg->alloc || !cfg->free)
|
|
return -EINVAL;
|
|
|
|
/* Make sure the format supports custom allocators. */
|
|
if (io_pgtable_init_table[fmt]->caps & IO_PGTABLE_CAP_CUSTOM_ALLOCATOR)
|
|
return 0;
|
|
|
|
return -EINVAL;
|
|
}
|
|
|
|
struct io_pgtable_ops *alloc_io_pgtable_ops(enum io_pgtable_fmt fmt,
|
|
struct io_pgtable_cfg *cfg,
|
|
void *cookie)
|
|
{
|
|
struct io_pgtable *iop;
|
|
const struct io_pgtable_init_fns *fns;
|
|
|
|
if (fmt >= IO_PGTABLE_NUM_FMTS)
|
|
return NULL;
|
|
|
|
if (check_custom_allocator(fmt, cfg))
|
|
return NULL;
|
|
|
|
fns = io_pgtable_init_table[fmt];
|
|
if (!fns)
|
|
return NULL;
|
|
|
|
iop = fns->alloc(cfg, cookie);
|
|
if (!iop)
|
|
return NULL;
|
|
|
|
iop->fmt = fmt;
|
|
iop->cookie = cookie;
|
|
iop->cfg = *cfg;
|
|
|
|
return &iop->ops;
|
|
}
|
|
EXPORT_SYMBOL_GPL(alloc_io_pgtable_ops);
|
|
|
|
/*
|
|
* It is the IOMMU driver's responsibility to ensure that the page table
|
|
* is no longer accessible to the walker by this point.
|
|
*/
|
|
void free_io_pgtable_ops(struct io_pgtable_ops *ops)
|
|
{
|
|
struct io_pgtable *iop;
|
|
|
|
if (!ops)
|
|
return;
|
|
|
|
iop = io_pgtable_ops_to_pgtable(ops);
|
|
io_pgtable_tlb_flush_all(iop);
|
|
io_pgtable_init_table[iop->fmt]->free(iop);
|
|
}
|
|
EXPORT_SYMBOL_GPL(free_io_pgtable_ops);
|