539 lines
19 KiB
C

/*
* This program is free software and is provided to you under the terms of the
* GNU General Public License version 2 as published by the Free Software
* Foundation, and any use by you of this program is subject to the terms
* of such GNU licence.
*
* A copy of the licence is included with the program, and can also be obtained
* from Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
#include "linux/mman.h"
#include <linux/version_compat_defs.h>
#include <mali_kbase.h>
#include <mali_kbase_reg_track.h>
/* mali_kbase_mmap.c
*
* This file contains Linux specific implementation of
* kbase_context_get_unmapped_area() interface.
*/
/**
* shader_code_align_and_check() - Align the specified pointer according to shader code
* requirement.
*
* @gap_end: Highest possible start address for alignment. The caller must ensure
* the input has already been properly aligned with info contained fields.
* @info: vm_unmapped_area_info structure passed, containing alignment, length
* and limits for the allocation
* The function only undertakes the shader code alignment adjustment. It's the caller's
* responsibility that the input value provided via gap_end has already been properly aligned
* in compliance to the fields specified in the info structure. Irrespective the return result,
* the value of the variable pointed by the pointer gap_end may have been decreased in
* reaching the required alignment, but will not drop below info->low_limit.
*
* Return: true if gap_end is now aligned correctly, false otherwise
*/
static bool shader_code_align_and_check(unsigned long *gap_end, struct vm_unmapped_area_info *info)
{
unsigned long align_adjust = (info->align_offset ? info->align_offset : info->length);
unsigned long align_floor = info->low_limit + align_adjust;
/* Check for 4GB address inner high-bit pattern, make adjustment if all zeros */
if (0 == (*gap_end & BASE_MEM_MASK_4GB) && *gap_end >= align_floor)
(*gap_end) -= align_adjust;
if (0 == ((*gap_end + info->length) & BASE_MEM_MASK_4GB) && *gap_end >= align_floor)
(*gap_end) -= align_adjust;
return ((*gap_end & BASE_MEM_MASK_4GB) && ((*gap_end + info->length) & BASE_MEM_MASK_4GB));
}
/**
* align_4gb_no_straddle() - Align the specified pointer not to straddle over a 4_GB boundary.
*
* @gap_end: Highest possible start address for alignment. The caller must ensure
* the input has already been properly aligned with info contained fields.
* @info: vm_unmapped_area_info structure passed, containing alignment, length
* and limits for the allocation
*
* The function only undertakes the 4GB boundary alignment adjustment. It's the caller's
* responsibility that the input value provided via gap_end has already been properly aligned
* in compliance to the fields specified in the info structure.
*
* Return: true is always expected and the gap_end is aligned correctly, false can only
* be possible when the code has been wrongly modified.
*/
static bool align_4gb_no_straddle(unsigned long *gap_end, struct vm_unmapped_area_info *info)
{
unsigned long start = *gap_end;
unsigned long end = *gap_end + info->length;
unsigned long mask = ~((unsigned long)U32_MAX);
/* Check if 4GB boundary is straddled */
if ((start & mask) != ((end - 1) & mask)) {
unsigned long offset = end - (end & mask);
/* This is to ensure that alignment doesn't get
* disturbed in an attempt to prevent straddling at
* 4GB boundary. The GPU VA is aligned to 2MB when the
* allocation size is > 2MB and there is enough CPU &
* GPU virtual space.
*/
unsigned long rounded_offset = ALIGN(offset, info->align_mask + 1);
start -= rounded_offset;
end -= rounded_offset;
/* Patch gap_end to use new starting address for VA region */
*gap_end = start;
/* The preceding 4GB boundary shall not get straddled,
* even after accounting for the alignment, as the
* size of allocation is limited to 4GB and the initial
* start location was already aligned.
*/
if (WARN_ONCE((start & mask) != ((end - 1) & mask),
"Alignment unexpected straddles over 4GB boundary!"))
return false;
}
return true;
}
#if (KERNEL_VERSION(6, 1, 0) > LINUX_VERSION_CODE) || !defined(__ANDROID_COMMON_KERNEL__)
/**
* align_and_check() - Align the specified pointer to the provided alignment and
* check that it is still in range. For Kernel versions below
* 6.1, it requires that the length of the alignment is already
* extended by a worst-case alignment mask.
* @gap_end: Highest possible start address for allocation (end of gap in
* address space)
* @gap_start: Start address of current memory area / gap in address space
* @info: vm_unmapped_area_info structure passed to caller, containing
* alignment, length and limits for the allocation
* @is_shader_code: True if the allocation is for shader code (which has
* additional alignment requirements)
* @is_same_4gb_page: True if the allocation needs to reside completely within
* a 4GB chunk
*
* Return: true if gap_end is now aligned correctly and is still in range,
* false otherwise
*/
static bool align_and_check(unsigned long *gap_end, unsigned long gap_start,
struct vm_unmapped_area_info *info, bool is_shader_code,
bool is_same_4gb_page)
{
/* Compute highest gap address at the desired alignment */
*gap_end -= info->length;
*gap_end -= (*gap_end - info->align_offset) & info->align_mask;
if (is_shader_code) {
if (!shader_code_align_and_check(gap_end, info))
return false;
} else if (is_same_4gb_page)
if (!align_4gb_no_straddle(gap_end, info))
return false;
if ((*gap_end < info->low_limit) || (*gap_end < gap_start))
return false;
return true;
}
#endif
/**
* kbase_unmapped_area_topdown() - allocates new areas top-down from
* below the stack limit.
* @info: Information about the memory area to allocate.
* @is_shader_code: Boolean which denotes whether the allocated area is
* intended for the use by shader core in which case a
* special alignment requirements apply.
* @is_same_4gb_page: Boolean which indicates whether the allocated area needs
* to reside completely within a 4GB chunk.
*
* The unmapped_area_topdown() function in the Linux kernel is not exported
* using EXPORT_SYMBOL_GPL macro. To allow us to call this function from a
* module and also make use of the fact that some of the requirements for
* the unmapped area are known in advance, we implemented an extended version
* of this function and prefixed it with 'kbase_'.
*
* The difference in the call parameter list comes from the fact that
* kbase_unmapped_area_topdown() is called with additional parameters which
* are provided to indicate whether the allocation is for a shader core memory,
* which has additional alignment requirements, and whether the allocation can
* straddle a 4GB boundary.
*
* The modification of the original Linux function lies in how the computation
* of the highest gap address at the desired alignment is performed once the
* gap with desirable properties is found. For this purpose a special function
* is introduced (@ref align_and_check()) which beside computing the gap end
* at the desired alignment also performs additional alignment checks for the
* case when the memory is executable shader core memory, for which it is
* ensured that the gap does not end on a 4GB boundary, and for the case when
* memory needs to be confined within a 4GB chunk.
*
* Return: address of the found gap end (high limit) if area is found;
* -ENOMEM if search is unsuccessful
*/
static unsigned long kbase_unmapped_area_topdown(struct vm_unmapped_area_info *info,
bool is_shader_code, bool is_same_4gb_page)
{
#if (KERNEL_VERSION(6, 1, 0) > LINUX_VERSION_CODE)
struct mm_struct *mm = current->mm;
struct vm_area_struct *vma;
unsigned long length, low_limit, high_limit, gap_start, gap_end;
/* Adjust search length to account for worst case alignment overhead */
length = info->length + info->align_mask;
if (length < info->length)
return -ENOMEM;
/*
* Adjust search limits by the desired length.
* See implementation comment at top of unmapped_area().
*/
gap_end = info->high_limit;
if (gap_end < length)
return -ENOMEM;
high_limit = gap_end - length;
if (info->low_limit > high_limit)
return -ENOMEM;
low_limit = info->low_limit + length;
/* Check highest gap, which does not precede any rbtree node */
gap_start = mm->highest_vm_end;
if (gap_start <= high_limit) {
if (align_and_check(&gap_end, gap_start, info, is_shader_code, is_same_4gb_page))
return gap_end;
}
/* Check if rbtree root looks promising */
if (RB_EMPTY_ROOT(&mm->mm_rb))
return -ENOMEM;
vma = rb_entry(mm->mm_rb.rb_node, struct vm_area_struct, vm_rb);
if (vma->rb_subtree_gap < length)
return -ENOMEM;
while (true) {
/* Visit right subtree if it looks promising */
gap_start = vma->vm_prev ? vma->vm_prev->vm_end : 0;
if (gap_start <= high_limit && vma->vm_rb.rb_right) {
struct vm_area_struct *right =
rb_entry(vma->vm_rb.rb_right, struct vm_area_struct, vm_rb);
if (right->rb_subtree_gap >= length) {
vma = right;
continue;
}
}
check_current:
/* Check if current node has a suitable gap */
gap_end = vma->vm_start;
if (gap_end < low_limit)
return -ENOMEM;
if (gap_start <= high_limit && gap_end - gap_start >= length) {
/* We found a suitable gap. Clip it with the original
* high_limit.
*/
if (gap_end > info->high_limit)
gap_end = info->high_limit;
if (align_and_check(&gap_end, gap_start, info, is_shader_code,
is_same_4gb_page))
return gap_end;
}
/* Visit left subtree if it looks promising */
if (vma->vm_rb.rb_left) {
struct vm_area_struct *left =
rb_entry(vma->vm_rb.rb_left, struct vm_area_struct, vm_rb);
if (left->rb_subtree_gap >= length) {
vma = left;
continue;
}
}
/* Go back up the rbtree to find next candidate node */
while (true) {
struct rb_node *prev = &vma->vm_rb;
if (!rb_parent(prev))
return -ENOMEM;
vma = rb_entry(rb_parent(prev), struct vm_area_struct, vm_rb);
if (prev == vma->vm_rb.rb_right) {
gap_start = vma->vm_prev ? vma->vm_prev->vm_end : 0;
goto check_current;
}
}
}
#else /* KERNEL_VERSION(6, 1, 0) > LINUX_VERSION_CODE */
#ifdef __ANDROID_COMMON_KERNEL__
struct vm_unmapped_area_info tmp_info = *info;
unsigned long length;
tmp_info.flags |= VM_UNMAPPED_AREA_TOPDOWN;
if (!(is_shader_code || is_same_4gb_page))
return vm_unmapped_area(&tmp_info);
length = info->length + info->align_mask;
/* Due to additional alignment requirement, shader_code or same_4gb_page
* needs iterations for alignment search and confirmation check.
*/
while (true) {
unsigned long saved_high_lmt = tmp_info.high_limit;
unsigned long gap_end, start, rev_high_limit;
gap_end = vm_unmapped_area(&tmp_info);
if (IS_ERR_VALUE(gap_end))
return gap_end;
start = gap_end;
if (is_shader_code) {
bool shader_code_aligned;
unsigned long align_cmp_ref;
while (true) {
/* Save the start value for progress check. the loop needs
* to end if the alignment can't progress any further.
* In summary, the loop ends condition here is either:
* 1. shader_code_aligned is true; or
* 2. align_cmp_ref == gap_end.
*/
align_cmp_ref = gap_end;
shader_code_aligned =
shader_code_align_and_check(&gap_end, &tmp_info);
if (shader_code_aligned || (align_cmp_ref == gap_end))
break;
}
if (shader_code_aligned) {
if (start == gap_end)
return gap_end;
rev_high_limit = gap_end + length;
} else
break;
} else {
/* must be same_4gb_page case */
if (likely(align_4gb_no_straddle(&gap_end, &tmp_info))) {
if (start == gap_end)
return gap_end;
rev_high_limit = gap_end + length;
} else
break;
}
if (rev_high_limit < info->low_limit)
break;
if (WARN_ONCE(rev_high_limit >= saved_high_lmt,
"Unexpected recurring high_limit in search, %lx => %lx\n"
"\tinfo-input: limit=[%lx, %lx], mask=%lx, len=%lx\n",
saved_high_lmt, rev_high_limit, info->low_limit, info->high_limit,
info->align_mask, info->length))
rev_high_limit = saved_high_lmt -
(info->align_offset ? info->align_offset : info->length);
/* Repeat the search with a decreasing rev_high_limit */
tmp_info.high_limit = rev_high_limit;
}
#else /* __ANDROID_COMMON_KERNEL__ */
unsigned long length, high_limit;
MA_STATE(mas, &current->mm->mm_mt, 0, 0);
/* Adjust search length to account for worst case alignment overhead */
length = info->length + info->align_mask;
if (length < info->length)
return -ENOMEM;
high_limit = info->high_limit;
if ((high_limit - info->low_limit) < length)
return -ENOMEM;
while (true) {
unsigned long gap_start, gap_end;
unsigned long saved_high_lmt = high_limit;
if (mas_empty_area_rev(&mas, info->low_limit, high_limit - 1, length))
return -ENOMEM;
gap_end = mas.last + 1;
gap_start = mas.index;
if (align_and_check(&gap_end, gap_start, info, is_shader_code, is_same_4gb_page))
return gap_end;
if (gap_end < info->low_limit)
return -ENOMEM;
/* Adjust next search high limit */
high_limit = gap_end + length;
if (WARN_ONCE(high_limit >= saved_high_lmt,
"Unexpected recurring high_limit in search, %lx => %lx\n"
"\tinfo-input: limit=[%lx, %lx], mask=%lx, len=%lx\n",
saved_high_lmt, high_limit, info->low_limit, info->high_limit,
info->align_mask, info->length))
high_limit = saved_high_lmt -
(info->align_offset ? info->align_offset : info->length);
mas_reset(&mas);
}
#endif /* __ANDROID_COMMON_KERNEL__ */
#endif /* KERNEL_VERSION(6, 1, 0) > LINUX_VERSION_CODE */
return -ENOMEM;
}
/* This function is based on Linux kernel's arch_get_unmapped_area, but
* simplified slightly. Modifications come from the fact that some values
* about the memory area are known in advance.
*/
unsigned long kbase_context_get_unmapped_area(struct kbase_context *const kctx,
const unsigned long addr, const unsigned long len,
const unsigned long pgoff, const unsigned long flags)
{
struct mm_struct *mm = current->mm;
struct vm_unmapped_area_info info;
unsigned long align_offset = 0;
unsigned long align_mask = 0;
#if (KERNEL_VERSION(6, 1, 0) <= LINUX_VERSION_CODE)
unsigned long high_limit = arch_get_mmap_base(addr, mm->mmap_base);
unsigned long low_limit = max_t(unsigned long, PAGE_SIZE, kbase_mmap_min_addr);
#else
unsigned long high_limit = mm->mmap_base;
unsigned long low_limit = PAGE_SIZE;
#endif
unsigned int cpu_va_bits = BITS_PER_LONG;
unsigned int gpu_pc_bits = kctx->kbdev->gpu_props.log2_program_counter_size;
bool is_shader_code = false;
bool is_same_4gb_page = false;
unsigned long ret;
/* the 'nolock' form is used here:
* - the base_pfn of the SAME_VA zone does not change
* - in normal use, va_size_pages is constant once the first allocation
* begins
*
* However, in abnormal use this function could be processing whilst
* another new zone is being setup in a different thread (e.g. to
* borrow part of the SAME_VA zone). In the worst case, this path may
* witness a higher SAME_VA end_pfn than the code setting up the new
* zone.
*
* This is safe because once we reach the main allocation functions,
* we'll see the updated SAME_VA end_pfn and will determine that there
* is no free region at the address found originally by too large a
* same_va_end_addr here, and will fail the allocation gracefully.
*/
struct kbase_reg_zone *zone = kbase_ctx_reg_zone_get_nolock(kctx, SAME_VA_ZONE);
u64 same_va_end_addr = kbase_reg_zone_end_pfn(zone) << PAGE_SHIFT;
#if (KERNEL_VERSION(6, 1, 0) <= LINUX_VERSION_CODE)
const unsigned long mmap_end = arch_get_mmap_end(addr, len, flags);
/* requested length too big for entire address space */
if (len > mmap_end - kbase_mmap_min_addr)
return -ENOMEM;
#endif
/* err on fixed address */
if ((flags & MAP_FIXED) || addr)
return -EINVAL;
#if IS_ENABLED(CONFIG_64BIT)
/* too big? */
if (len > TASK_SIZE - SZ_2M)
return -ENOMEM;
if (!kbase_ctx_flag(kctx, KCTX_COMPAT)) {
high_limit = min_t(unsigned long, high_limit, same_va_end_addr);
/* If there's enough (> 33 bits) of GPU VA space, align
* to 2MB boundaries.
*/
if (kctx->kbdev->gpu_props.mmu.va_bits > 33) {
if (len >= SZ_2M) {
align_offset = SZ_2M;
align_mask = SZ_2M - 1;
}
}
low_limit = SZ_2M;
} else {
cpu_va_bits = 32;
}
#endif /* CONFIG_64BIT */
if ((PFN_DOWN(BASE_MEM_COOKIE_BASE) <= pgoff) &&
(PFN_DOWN(BASE_MEM_FIRST_FREE_ADDRESS) > pgoff)) {
int cookie = pgoff - PFN_DOWN(BASE_MEM_COOKIE_BASE);
struct kbase_va_region *reg;
/* Need to hold gpu vm lock when using reg */
kbase_gpu_vm_lock(kctx);
reg = kctx->pending_regions[cookie];
if (!reg) {
kbase_gpu_vm_unlock(kctx);
return -EINVAL;
}
if (!(reg->flags & KBASE_REG_GPU_NX)) {
if (cpu_va_bits > gpu_pc_bits) {
align_offset = 1ULL << gpu_pc_bits;
align_mask = align_offset - 1;
is_shader_code = true;
}
#if !MALI_USE_CSF
} else if (reg->flags & KBASE_REG_TILER_ALIGN_TOP) {
unsigned long extension_bytes =
(unsigned long)(reg->extension << PAGE_SHIFT);
/* kbase_check_alloc_sizes() already satisfies
* these checks, but they're here to avoid
* maintenance hazards due to the assumptions
* involved
*/
WARN_ON(reg->extension > (ULONG_MAX >> PAGE_SHIFT));
WARN_ON(reg->initial_commit > (ULONG_MAX >> PAGE_SHIFT));
WARN_ON(!is_power_of_2(extension_bytes));
align_mask = extension_bytes - 1;
align_offset = extension_bytes - (reg->initial_commit << PAGE_SHIFT);
#endif /* !MALI_USE_CSF */
} else if (reg->flags & KBASE_REG_GPU_VA_SAME_4GB_PAGE) {
is_same_4gb_page = true;
}
kbase_gpu_vm_unlock(kctx);
#ifndef CONFIG_64BIT
} else {
return current->mm->get_unmapped_area(kctx->filp, addr, len, pgoff, flags);
#endif
}
info.flags = 0;
info.length = len;
info.low_limit = low_limit;
info.high_limit = high_limit;
info.align_offset = align_offset;
info.align_mask = align_mask;
ret = kbase_unmapped_area_topdown(&info, is_shader_code, is_same_4gb_page);
if (IS_ERR_VALUE(ret) && high_limit == mm->mmap_base && high_limit < same_va_end_addr) {
#if (KERNEL_VERSION(6, 1, 0) <= LINUX_VERSION_CODE)
/* Retry above TASK_UNMAPPED_BASE */
info.low_limit = TASK_UNMAPPED_BASE;
info.high_limit = min_t(u64, mmap_end, same_va_end_addr);
#else
/* Retry above mmap_base */
info.low_limit = mm->mmap_base;
info.high_limit = min_t(u64, TASK_SIZE, same_va_end_addr);
#endif
ret = kbase_unmapped_area_topdown(&info, is_shader_code, is_same_4gb_page);
}
return ret;
}