u-boot.git/lib/lmb.c, branch v2025.01

lmb: Return -EEXIST in lmb_add_region_flags() if region already added

2024-12-12T15:20:32Z

An attempt to add the already added LMB region using lmb_add_region_flags() ends up in lmb_addrs_overlap() check, which eventually leads to either returning 0 if 'flags' is LMB_NONE, or -1 otherwise. It makes it impossible for the user of this function to catch the case when the region is already added and differentiate it from regular errors. That in turn may lead to incorrect error handling in the caller code, like reporting misleading errors or interrupting the normal code path where it could be treated as the normal case. An example is boot_fdt_reserve_region() function, which might be called twice (e.g. during board startup in initr_lmb(), and then during 'booti' command booting the OS), thus trying to reserve exactly the same memory regions described in the device tree twice, which produces an error message on second call. Return -EEXIST error code in case when the added region exists and it's not LMB_NONE; for LMB_NONE return 0, to conform to unit tests (specifically test_alloc_addr() in test/lib/lmb.c) and the preferred behavior described in commit 1d9aa4a283da ("lmb: Fix the allocation of overlapping memory areas with !LMB_NONE"). The change of lmb_add_region_flags() return values is described in the table below: Return case Pre-1d9 1d9 New ----------------------------------------------------------- Added successfully 0 0 0 Failed to add -1 -1 -1 Already added, flags == LMB_NONE 0 0 0 Already added, flags != LMB_NONE 0 -1 -EEXIST Rework all affected functions and their documentation. Also fix the corresponding unit test which checks reserving the same region with the same flags to account for the changed return value. No functional change is intended (by this patch itself). Fixes: 1d9aa4a283da ("lmb: Fix the allocation of overlapping memory areas with !LMB_NONE") Signed-off-by: Sam Protsenko Reviewed-by: Ilias Apalodimas Tested-by: Michal Simek

lmb: prohibit allocations above ram_top even from same bank

2024-12-06T23:47:23Z

There are platforms which set the value of ram_top based on certain restrictions that the platform might have in accessing memory above ram_top, even when the memory region is in the same DRAM bank. So, even though the LMB allocator works as expected, when trying to allocate memory above ram_top, prohibit this by marking all memory above ram_top as reserved, even if the said memory region is from the same bank. Signed-off-by: Sughosh Ganu Tested-by: Andreas Schwab

lmb: Fix the allocation of overlapping memory areas with !LMB_NONE

2024-12-05T07:01:44Z

At the moment the LMB allocator will return 'success' immediately on two consecutive allocations if the second one is smaller and the flags match without resizing the reserved area. This is problematic for two reasons, first of all the new updated allocation won't update the size and we end up holding more memory than needed, but most importantly it breaks the EFI SCT tests since EFI now allocates via LMB. More specifically when EFI requests a specific address twice with the EFI_ALLOCATE_ADDRESS flag set, the first allocation will succeed and update the EFI memory map. Due to the LMB behavior the second allocation will also succeed but the address ranges are already in the EFI memory map due the first allocation. EFI will then fail to update the memory map, returning EFI_OUT_OF_RESOURCES instead of EFI_NOT_FOUND which break EFI conformance. So let's remove the fast check with is problematic anyway and leave LMB resize and calculate address properly. LMB will now - try to resize the reservations for LMB_NONE - return -1 if the memory is not LMB_NONE and already reserved The LMB code needs some cleanup in that part, but since we are close to 2025.01 do the easy fix and plan to refactor it later. Also update the dm tests with the new behavior. Fixes: commit 22f2c9ed9f53 ("efi: memory: use the lmb API's for allocating and freeing memory") Signed-off-by: Ilias Apalodimas

lmb.c: add missing comma in lmb_dump_region()

2024-11-15T00:14:06Z

In the message string " %s[%d]\t[0x%llx-0x%llx], 0x%08llx bytes flags: " a comma is missing before flags. To avoid increasing the code size replace '0x%' by '%#'. Printing the size with leading zeros but not the addresses does not really make sense. Remove the leading zeros from the size output. Signed-off-by: Heinrich Schuchardt [trini: Fix test/cmd/bdinfo.c for these changes] Signed-off-by: Tom Rini

lmb: do not panic in lmb_print_region_flags

2024-11-15T00:14:05Z

Commit c3cf0dc64f1c ("lmb: add a check to prevent memory overrun") addressed a possible buffer overrun using assert_noisy(). Resetting via panic() in lmb_print_region() while allowing invalid lmb flags elsewhere is not reasonable. Instead of panicking print a message indicating the problem. fls() returns an int. Using a u64 for bitpos does not match. Use int instead. fls() takes an int as argument. Using 1ull << bitpos generates a u64. Use 1u << bitpos instead. Signed-off-by: Heinrich Schuchardt Acked-by: Sughosh Ganu

lmb: Add basic io_lmb functionality

2024-11-11T13:26:44Z

These functions can be used with struct lmb pointers and will be used to manage IOVA space in the apple_dart iommu driver. This restores part of the pointer base struct lmb API from before commit ed17a33fed29 ("lmb: make LMB memory map persistent and global"). io_lmb_add() and io_lmb_free() can trivially reuse exisiting lmb functions. io_lmb_setup() is separate for unique error log messages. io_lmb_alloc() is a simplified copy of _lmb_alloc_base() since the later has unused features and internal use of the global LMB memory map. Signed-off-by: Janne Grunau

lmb: cosmetic: reorder functions and global LMB variable

2024-11-11T13:26:44Z

Low lovel LMB functionality will be used to manage IOVA space in the Apple dart iommu driver. This reordering ensures that those function can not access the global LMB memory map variable. Signed-off-by: Janne Grunau

lmb: Do not use global LMB variable in _lmb_free()

2024-11-11T13:26:44Z

It will be re-used with a lmb list pointer as argument for IOVA allocations in the apple_dart iommu driver. Reviewed-by: Tom Rini Signed-off-by: Janne Grunau

lmb: Drop extra 16KB of stack space

2024-11-09T08:52:43Z

There is already a defined stack-size which is used to reserve space for the stack. It is confusing to add more in the lmb module, since then the memory map (with meminfo command) seems to have a hole in it. Drop this unnecessary feature. Signed-off-by: Simon Glass

lmb: remove __maybe_unused from lmb_map_update_notify

2024-11-01T19:36:47Z

Function lmb_map_update_notify() is always referenced. Signed-off-by: Heinrich Schuchardt Reviewed-by: Ilias Apalodimas