kernel.git/arch/x86/kernel/acpi/boot.c, branch linux-4.19.y

x86/i8259: Skip probing when ACPI/MADT advertises PCAT compatibility

2023-11-08T10:22:17Z

commit 128b0c9781c9f2651bea163cb85e52a6c7be0f9e upstream. David and a few others reported that on certain newer systems some legacy interrupts fail to work correctly. Debugging revealed that the BIOS of these systems leaves the legacy PIC in uninitialized state which makes the PIC detection fail and the kernel switches to a dummy implementation. Unfortunately this fallback causes quite some code to fail as it depends on checks for the number of legacy PIC interrupts or the availability of the real PIC. In theory there is no reason to use the PIC on any modern system when IO/APIC is available, but the dependencies on the related checks cannot be resolved trivially and on short notice. This needs lots of analysis and rework. The PIC detection has been added to avoid quirky checks and force selection of the dummy implementation all over the place, especially in VM guest scenarios. So it's not an option to revert the relevant commit as that would break a lot of other scenarios. One solution would be to try to initialize the PIC on detection fail and retry the detection, but that puts the burden on everything which does not have a PIC. Fortunately the ACPI/MADT table header has a flag field, which advertises in bit 0 that the system is PCAT compatible, which means it has a legacy 8259 PIC. Evaluate that bit and if set avoid the detection routine and keep the real PIC installed, which then gets initialized (for nothing) and makes the rest of the code with all the dependencies work again. Fixes: e179f6914152 ("x86, irq, pic: Probe for legacy PIC and set legacy_pic appropriately") Reported-by: David Lazar Signed-off-by: Thomas Gleixner Tested-by: David Lazar Reviewed-by: Hans de Goede Reviewed-by: Mario Limonciello Cc: stable@vger.kernel.org Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218003 Link: https://lore.kernel.org/r/875y2u5s8g.ffs@tglx Signed-off-by: Greg Kroah-Hartman

ACPI / x86: Work around broken XSDT on Advantech DAC-BJ01 board

2022-03-28T06:41:44Z

commit e702196bf85778f2c5527ca47f33ef2e2fca8297 upstream. On this board the ACPI RSDP structure points to both a RSDT and an XSDT, but the XSDT points to a truncated FADT. This causes all sorts of trouble and usually a complete failure to boot after the following error occurs: ACPI Error: Unsupported address space: 0x20 (*/hwregs-*) ACPI Error: AE_SUPPORT, Unable to initialize fixed events (*/evevent-*) ACPI: Unable to start ACPI Interpreter This leaves the ACPI implementation in such a broken state that subsequent kernel subsystem initialisations go wrong, resulting in among others mismapped PCI memory, SATA and USB enumeration failures, and freezes. As this is an older embedded platform that will likely never see any BIOS updates to address this issue and its default shipping OS only complies to ACPI 1.0, work around this by forcing `acpi=rsdt`. This patch, applied on top of Linux 5.10.102, was confirmed on real hardware to fix the issue. Signed-off-by: Mark Cilissen Cc: All applicable Reviewed-by: Hans de Goede Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman

ACPI: tables: x86: Reserve memory occupied by ACPI tables

2021-05-07T08:49:25Z

commit 1a1c130ab7575498eed5bcf7220037ae09cd1f8a upstream. The following problem has been reported by George Kennedy: Since commit 7fef431be9c9 ("mm/page_alloc: place pages to tail in __free_pages_core()") the following use after free occurs intermittently when ACPI tables are accessed. BUG: KASAN: use-after-free in ibft_init+0x134/0xc49 Read of size 4 at addr ffff8880be453004 by task swapper/0/1 CPU: 3 PID: 1 Comm: swapper/0 Not tainted 5.12.0-rc1-7a7fd0d #1 Call Trace: dump_stack+0xf6/0x158 print_address_description.constprop.9+0x41/0x60 kasan_report.cold.14+0x7b/0xd4 __asan_report_load_n_noabort+0xf/0x20 ibft_init+0x134/0xc49 do_one_initcall+0xc4/0x3e0 kernel_init_freeable+0x5af/0x66b kernel_init+0x16/0x1d0 ret_from_fork+0x22/0x30 ACPI tables mapped via kmap() do not have their mapped pages reserved and the pages can be "stolen" by the buddy allocator. Apparently, on the affected system, the ACPI table in question is not located in "reserved" memory, like ACPI NVS or ACPI Data, that will not be used by the buddy allocator, so the memory occupied by that table has to be explicitly reserved to prevent the buddy allocator from using it. In order to address this problem, rearrange the initialization of the ACPI tables on x86 to locate the initial tables earlier and reserve the memory occupied by them. The other architectures using ACPI should not be affected by this change. Link: https://lore.kernel.org/linux-acpi/1614802160-29362-1-git-send-email-george.kennedy@oracle.com/ Reported-by: George Kennedy Tested-by: George Kennedy Signed-off-by: Rafael J. Wysocki Reviewed-by: Mike Rapoport Cc: 5.10+ # 5.10+ Signed-off-by: Greg Kroah-Hartman

acpi/x86: ignore unspecified bit positions in the ACPI global lock field

2020-04-17T08:48:45Z

commit ecb9c790999fd6c5af0f44783bd0217f0b89ec2b upstream. The value in "new" is constructed from "old" such that all bits defined as reserved by the ACPI spec[1] are left untouched. But if those bits do not happen to be all zero, "new < 3" will not evaluate to true. The firmware of the laptop(s) Medion MD63490 / Akoya P15648 comes with garbage inside the "FACS" ACPI table. The starting value is old=0x4944454d, therefore new=0x4944454e, which is >= 3. Mask off the reserved bits. [1] https://uefi.org/sites/default/files/resources/ACPI_6_2.pdf Link: https://bugzilla.kernel.org/show_bug.cgi?id=206553 Cc: All applicable Signed-off-by: Jan Engelhardt Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman

x86/acpi: Prevent X2APIC id 0xffffffff from being accounted

2018-04-17T09:56:31Z

RongQing reported that there are some X2APIC id 0xffffffff in his machine's ACPI MADT table, which makes the number of possible CPU inaccurate. The reason is that the ACPI X2APIC parser has no sanity check for APIC ID 0xffffffff, which is an invalid id in all APIC types. See "Intel® 64 Architecture x2APIC Specification", Chapter 2.4.1. Add a sanity check to acpi_parse_x2apic() which ignores the invalid id. Reported-by: Li RongQing Signed-off-by: Dou Liyang Signed-off-by: Thomas Gleixner Cc: stable@vger.kernel.org Cc: len.brown@intel.com Cc: rjw@rjwysocki.net Cc: hpa@zytor.com Link: https://lkml.kernel.org/r/20180412014052.25186-1-douly.fnst@cn.fujitsu.com

Merge branch 'WIP.x86/asm' into x86/urgent, because the topic is ready

2018-04-12T07:42:34Z

Signed-off-by: Ingo Molnar

x86/apic: Fix signedness bug in APIC ID validity checks

2018-04-10T14:46:39Z

The APIC ID as parsed from ACPI MADT is validity checked with the apic->apic_id_valid() callback, which depends on the selected APIC type. For non X2APIC types APIC IDs >= 0xFF are invalid, but values > 0x7FFFFFFF are detected as valid. This happens because the 'apicid' argument of the apic_id_valid() callback is type 'int'. So the resulting comparison apicid < 0xFF evaluates to true for all unsigned int values > 0x7FFFFFFF which are handed to default_apic_id_valid(). As a consequence, invalid APIC IDs in !X2APIC mode are considered valid and accounted as possible CPUs. Change the apicid argument type of the apic_id_valid() callback to u32 so the evaluation is unsigned and returns the correct result. [ tglx: Massaged changelog ] Signed-off-by: Li RongQing Signed-off-by: Thomas Gleixner Cc: stable@vger.kernel.org Cc: jgross@suse.com Cc: Dou Liyang Cc: Peter Zijlstra Cc: hpa@zytor.com Link: https://lkml.kernel.org/r/1523322966-10296-1-git-send-email-lirongqing@baidu.com

ACPI, x86/boot: Introduce the ->reduced_hw_early_init() ACPI callback

2018-03-12T11:32:57Z

Some ACPI hardware reduced platforms need to initialize certain devices defined by the ACPI hardware specification even though in principle those devices should not be present in an ACPI hardware reduced platform. To allow that to happen, make it possible to override the generic x86_init callbacks and provide a custom legacy_pic value, add a new ->reduced_hw_early_init() callback to struct x86_init_acpi and make acpi_reduced_hw_init() use it. Signed-off-by: Andy Shevchenko Reviewed-by: Rafael J. Wysocki Cc: Eric Biederman Cc: Juergen Gross Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Rafael J . Wysocki Cc: Thomas Gleixner Cc: linux-acpi@vger.kernel.org Link: http://lkml.kernel.org/r/20180220180506.65523-2-andriy.shevchenko@linux.intel.com Signed-off-by: Ingo Molnar

ACPI, x86/boot: Split out acpi_generic_reduce_hw_init() and export

2018-03-12T11:32:57Z

This is a preparation patch to allow override the hardware reduced initialization on ACPI enabled platforms. No functional change intended. Signed-off-by: Andy Shevchenko Reviewed-by: Rafael J. Wysocki Cc: Eric Biederman Cc: Juergen Gross Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Rafael J . Wysocki Cc: Thomas Gleixner Cc: linux-acpi@vger.kernel.org Link: http://lkml.kernel.org/r/20180220180506.65523-1-andriy.shevchenko@linux.intel.com Signed-off-by: Ingo Molnar

ACPI: SPCR: Make SPCR available to x86

2018-02-07T10:39:58Z

SPCR is currently only enabled or ARM64 and x86 can use SPCR to setup an early console. General fixes include updating Documentation & Kconfig (for x86), updating comments, and changing parse_spcr() to acpi_parse_spcr(), and earlycon_init_is_deferred to earlycon_acpi_spcr_enable to be more descriptive. On x86, many systems have a valid SPCR table but the table version is not 2 so the table version check must be a warning. On ARM64 when the kernel parameter earlycon is used both the early console and console are enabled. On x86, only the earlycon should be enabled by by default. Modify acpi_parse_spcr() to allow options for initializing the early console and console separately. Signed-off-by: Prarit Bhargava Acked-by: Ingo Molnar Reviewed-by: Mark Salter Tested-by: Mark Salter Signed-off-by: Rafael J. Wysocki