kernel/drivers/ras/amd/atl/umc.c, branch linux-rolling-stable

RAS/AMD/ATL: Replace bitwise_xor_bits() with hweight16()

2025-11-24T16:00:37Z

Doing hweight16() and checking whether the lsb is set is functionally equivalent to what bitwise_xor_bits() does. In addition, it results in better generated code as before gcc would inline the function 4 times. With hweight16(), the resulting code boils down to 2 instructions - POPCNT and AND, and all relevant CPUs support POPCNT. An alternative would have been to use the __builtin_parity() function provided by both Clang/GCC, however under some circumstances the compiler can choose not to inline it but generate a library call which is unsupported in the kernel. No functional changes. [ bp: Massage commit message. ] Signed-off-by: Nikolay Borisov Signed-off-by: Borislav Petkov (AMD) Link: https://patch.msgid.link/20251124142517.1708451-1-nik.borisov@suse.com

RAS/AMD/ATL: Require PRM support for future systems

2025-10-27T18:56:41Z

Currently, the AMD Address Translation Library will fail to load for new, unrecognized systems (based on Data Fabric revision). The intention is to prevent the code from executing on new systems and returning incorrect results. Recent AMD systems, however, may provide UEFI PRM handlers for address translation. This is code provided by the platform through BIOS tables. These are the preferred method for translation, and the Linux native code can be used as a fallback. Future AMD systems are expected to provide PRM handlers by default. And Linux native code will not be used. Adjust the ATL init code so that new, unrecognized systems will default to using PRM handlers only. Signed-off-by: Yazen Ghannam Signed-off-by: Borislav Petkov (AMD) Reviewed-by: "Mario Limonciello (AMD)" Link: https://patch.msgid.link/all/20251017-wip-atl-prm-v2-2-7ab1df4a5fbc@amd.com

RAS/AMD/FMPM: Get masked address

2025-04-08T17:30:58Z

Some operations require checking, or ignoring, specific bits in an address value. For example, this can be comparing address values to identify unique structures. Currently, the full address value is compared when filtering for duplicates. This results in over counting and creation of extra records. This gives the impression that more unique events occurred than did in reality. Mask the address for physical rows on MI300. [ bp: Simplify. ] Fixes: 6f15e617cc99 ("RAS: Introduce a FRU memory poison manager") Signed-off-by: Yazen Ghannam Signed-off-by: Borislav Petkov (AMD) Cc: stable@vger.kernel.org

RAS/AMD/ATL: Include row[13] bit in row retirement

2025-04-07T13:06:06Z

Based on feedback from hardware folks, row[13] is part of the variable bits within a physical row (along with all column bits). Only half the physical addresses affected by a row are calculated if this bit is not included. Add the row[13] bit to the row retirement flow. Fixes: 3b566b30b414 ("RAS/AMD/ATL: Add MI300 row retirement support") Signed-off-by: Yazen Ghannam Signed-off-by: Borislav Petkov (AMD) Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20250401-fix-fmpm-extra-records-v1-1-840bcf7a8ac5@amd.com

RAS/AMD/ATL: Translate normalized to system physical addresses using PRM

2024-08-01T12:36:29Z

AMD Zen-based systems report memory error addresses through machine check banks representing Unified Memory Controllers (UMCs) in the form of UMC relative "normalized" addresses. A normalized address must be converted to a system physical address to be usable by the OS. Future AMD platforms will provide a UEFI PRM module that implements a number of address translation PRM handlers. This will provide an interface for the OS to call platform specific code without requiring the use of SMM or other heavy firmware operations. Add support for the normalized to system physical address translation PRM handler in the AMD Address Translation Library and prefer it over native code if available. The GUID and parameter buffer structure are specific to the normalized to system physical address handler provided by the address translation PRM module included in future AMD systems. The address translation PRM module is documented in chapter 22 of the publicly available "AMD Family 1Ah Models 00h–0Fh and Models 10h–1Fh ACPI v6.5 Porting Guide". [ bp: Massage commit message. ] Signed-off-by: John Allen Signed-off-by: Borislav Petkov (AMD) Link: https://lore.kernel.org/r/20240730151731.15363-3-john.allen@amd.com

RAS/AMD/ATL: Use system settings for MI300 DRAM to normalized address translation

2024-06-16T09:22:57Z

The currently used normalized address format is not applicable to all MI300 systems. This leads to incorrect results during address translation. Drop the fixed layout and construct the normalized address from system settings. Fixes: 87a612375307 ("RAS/AMD/ATL: Add MI300 DRAM to normalized address translation support") Signed-off-by: Yazen Ghannam Signed-off-by: Borislav Petkov (AMD) Cc: Link: https://lore.kernel.org/r/20240607-mi300-dram-xl-fix-v1-2-2f11547a178c@amd.com

RAS/AMD/ATL: Fix MI300 bank hash

2024-06-10T05:56:33Z

Apply the SID bits to the correct offset in the Bank value. Do this in the temporary value so they don't need to be masked off later. Fixes: 87a612375307 ("RAS/AMD/ATL: Add MI300 DRAM to normalized address translation support") Signed-off-by: Yazen Ghannam Signed-off-by: Borislav Petkov (AMD) Cc: Link: https://lore.kernel.org/r/20240607-mi300-dram-xl-fix-v1-1-2f11547a178c@amd.com

Merge tag 'edac_updates_for_v6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/ras/ras

2024-03-12T01:14:06Z

Pull EDAC updates from Borislav Petkov: - Add a FRU (Field Replaceable Unit) memory poison manager which collects and manages previously encountered hw errors in order to save them to persistent storage across reboots. Previously recorded errors are "replayed" upon reboot in order to poison memory which has caused said errors in the past. The main use case is stacked, on-chip memory which cannot simply be replaced so poisoning faulty areas of it and thus making them inaccessible is the only strategy to prolong its lifetime. - Add an AMD address translation library glue which converts the reported addresses of hw errors into system physical addresses in order to be used by other subsystems like memory failure, for example. Add support for MI300 accelerators to that library. - igen6: Add support for Alder Lake-N SoC - i10nm: Add Grand Ridge support - The usual fixlets and cleanups * tag 'edac_updates_for_v6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/ras/ras: EDAC/versal: Convert to platform remove callback returning void RAS/AMD/FMPM: Fix off by one when unwinding on error RAS/AMD/FMPM: Add debugfs interface to print record entries RAS/AMD/FMPM: Save SPA values RAS: Export helper to get ras_debugfs_dir RAS/AMD/ATL: Fix bit overflow in denorm_addr_df4_np2() RAS: Introduce a FRU memory poison manager RAS/AMD/ATL: Add MI300 row retirement support Documentation: Move RAS section to admin-guide EDAC/versal: Make the bit position of injected errors configurable EDAC/i10nm: Add Intel Grand Ridge micro-server support EDAC/igen6: Add one more Intel Alder Lake-N SoC support RAS/AMD/ATL: Add MI300 DRAM to normalized address translation support RAS/AMD/ATL: Fix array overflow in get_logical_coh_st_fabric_id_mi300() RAS/AMD/ATL: Add MI300 support Documentation: RAS: Add index and address translation section EDAC/amd64: Use new AMD Address Translation Library RAS: Introduce AMD Address Translation Library EDAC/synopsys: Convert to devm_platform_ioremap_resource()

RAS/AMD/ATL: Add MI300 row retirement support

2024-02-14T16:10:06Z

DRAM row retirement depends on model-specific information that is best done within the AMD Address Translation Library. Export a generic wrapper function for other modules to use. Add any model-specific helpers here. Signed-off-by: Yazen Ghannam Signed-off-by: Borislav Petkov (AMD) Link: https://lore.kernel.org/r/20240214033516.1344948-2-yazen.ghannam@amd.com

RAS/AMD/ATL: Add MI300 DRAM to normalized address translation support

2024-02-01T15:28:56Z

Zen-based AMD systems report DRAM ECC errors through Unified Memory Controller (UMC) MCA banks. The value provided in MCA_ADDR is a "normalized" address which represents the UMC's view of its managed memory. The normalized address must be translated to a system physical address for software to take action. MI300 systems, uniquely, do not provide a normalized address in MCA_ADDR for DRAM ECC errors. Rather, the "DRAM" address is reported. This value includes identifiers for the bank, row, column, pseudochannel and stack of the memory location. The DRAM address must be converted to a normalized address in order to be further translated to a system physical address. Add helper functions to do the DRAM to normalized translation for MI300 systems. The method is based on the fixed hardware layout of the on-chip memory. [ bp: Massage commit message, decapitalize some, rename function. ] Signed-off-by: Yazen Ghannam Co-developed-by: Muralidhara M K Signed-off-by: Muralidhara M K Signed-off-by: Borislav Petkov (AMD) Tested-by: Muralidhara M K Link: https://lore.kernel.org/r/20240131165732.88297-1-yazen.ghannam@amd.com