kernel.git/arch/x86/kernel/setup.c, branch linux-5.12.y

x86/thermal: Fix LVT thermal setup for SMI delivery mode

2021-06-10T11:41:47Z

commit 9a90ed065a155d13db0d0ffeaad5cc54e51c90c6 upstream. There are machines out there with added value crap^WBIOS which provide an SMI handler for the local APIC thermal sensor interrupt. Out of reset, the BSP on those machines has something like 0x200 in that APIC register (timestamps left in because this whole issue is timing sensitive): [ 0.033858] read lvtthmr: 0x330, val: 0x200 which means: - bit 16 - the interrupt mask bit is clear and thus that interrupt is enabled - bits [10:8] have 010b which means SMI delivery mode. Now, later during boot, when the kernel programs the local APIC, it soft-disables it temporarily through the spurious vector register: setup_local_APIC: ... /* * If this comes from kexec/kcrash the APIC might be enabled in * SPIV. Soft disable it before doing further initialization. */ value = apic_read(APIC_SPIV); value &= ~APIC_SPIV_APIC_ENABLED; apic_write(APIC_SPIV, value); which means (from the SDM): "10.4.7.2 Local APIC State After It Has Been Software Disabled ... * The mask bits for all the LVT entries are set. Attempts to reset these bits will be ignored." And this happens too: [ 0.124111] APIC: Switch to symmetric I/O mode setup [ 0.124117] lvtthmr 0x200 before write 0xf to APIC 0xf0 [ 0.124118] lvtthmr 0x10200 after write 0xf to APIC 0xf0 This results in CPU 0 soft lockups depending on the placement in time when the APIC soft-disable happens. Those soft lockups are not 100% reproducible and the reason for that can only be speculated as no one tells you what SMM does. Likely, it confuses the SMM code that the APIC is disabled and the thermal interrupt doesn't doesn't fire at all, leading to CPU 0 stuck in SMM forever... Now, before 4f432e8bb15b ("x86/mce: Get rid of mcheck_intel_therm_init()") due to how the APIC_LVTTHMR was read before APIC initialization in mcheck_intel_therm_init(), it would read the value with the mask bit 16 clear and then intel_init_thermal() would replicate it onto the APs and all would be peachy - the thermal interrupt would remain enabled. But that commit moved that reading to a later moment in intel_init_thermal(), resulting in reading APIC_LVTTHMR on the BSP too late and with its interrupt mask bit set. Thus, revert back to the old behavior of reading the thermal LVT register before the APIC gets initialized. Fixes: 4f432e8bb15b ("x86/mce: Get rid of mcheck_intel_therm_init()") Reported-by: James Feeney Signed-off-by: Borislav Petkov Cc: Cc: Zhang Rui Cc: Srinivas Pandruvada Link: https://lkml.kernel.org/r/YKIqDdFNaXYd39wz@zn.tnic Signed-off-by: Greg Kroah-Hartman

ACPI: x86: Call acpi_boot_table_init() after acpi_table_upgrade()

2021-04-13T14:03:01Z

Commit 1a1c130ab757 ("ACPI: tables: x86: Reserve memory occupied by ACPI tables") attempted to address an issue with reserving the memory occupied by ACPI tables, but it broke the initrd-based table override mechanism relied on by multiple users. To restore the initrd-based ACPI table override functionality, move the acpi_boot_table_init() invocation in setup_arch() on x86 after the acpi_table_upgrade() one. Fixes: 1a1c130ab757 ("ACPI: tables: x86: Reserve memory occupied by ACPI tables") Reported-by: Hans de Goede Tested-by: Hans de Goede Signed-off-by: Rafael J. Wysocki

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

2021-03-29T17:26:04Z

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+

sfi: Remove framework for deprecated firmware

2021-02-15T19:09:46Z

SFI-based platforms are gone. So does this framework. This removes mention of SFI through the drivers and other code as well. Signed-off-by: Andy Shevchenko Reviewed-by: Hans de Goede Acked-by: Linus Walleij Signed-off-by: Rafael J. Wysocki

Revert "x86/setup: don't remove E820_TYPE_RAM for pfn 0"

2021-02-04T18:26:53Z

This reverts commit bde9cfa3afe4324ec251e4af80ebf9b7afaf7afe. Changing the first memory page type from E820_TYPE_RESERVED to E820_TYPE_RAM makes it a part of "System RAM" resource rather than a reserved resource and this in turn causes devmem_is_allowed() to treat is as area that can be accessed but it is filled with zeroes instead of the actual data as previously. The change in /dev/mem output causes lilo to fail as was reported at slakware users forum, and probably other legacy applications will experience similar problems. Link: https://www.linuxquestions.org/questions/slackware-14/slackware-current-lilo-vesa-warnings-after-recent-updates-4175689617/#post6214439 Signed-off-by: Mike Rapoport Cc: stable@kernel.org Signed-off-by: Linus Torvalds

x86/setup: don't remove E820_TYPE_RAM for pfn 0

2021-01-24T17:20:52Z

Patch series "mm: fix initialization of struct page for holes in memory layout", v3. Commit 73a6e474cb37 ("mm: memmap_init: iterate over memblock regions rather that check each PFN") exposed several issues with the memory map initialization and these patches fix those issues. Initially there were crashes during compaction that Qian Cai reported back in April [1]. It seemed back then that the problem was fixed, but a few weeks ago Andrea Arcangeli hit the same bug [2] and there was an additional discussion at [3]. [1] https://lore.kernel.org/lkml/8C537EB7-85EE-4DCF-943E-3CC0ED0DF56D@lca.pw [2] https://lore.kernel.org/lkml/20201121194506.13464-1-aarcange@redhat.com [3] https://lore.kernel.org/mm-commits/20201206005401.qKuAVgOXr%akpm@linux-foundation.org This patch (of 2): The first 4Kb of memory is a BIOS owned area and to avoid its allocation for the kernel it was not listed in e820 tables as memory. As the result, pfn 0 was never recognised by the generic memory management and it is not a part of neither node 0 nor ZONE_DMA. If set_pfnblock_flags_mask() would be ever called for the pageblock corresponding to the first 2Mbytes of memory, having pfn 0 outside of ZONE_DMA would trigger VM_BUG_ON_PAGE(!zone_spans_pfn(page_zone(page), pfn), page); Along with reserving the first 4Kb in e820 tables, several first pages are reserved with memblock in several places during setup_arch(). These reservations are enough to ensure the kernel does not touch the BIOS area and it is not necessary to remove E820_TYPE_RAM for pfn 0. Remove the update of e820 table that changes the type of pfn 0 and move the comment describing why it was done to trim_low_memory_range() that reserves the beginning of the memory. Link: https://lkml.kernel.org/r/20210111194017.22696-2-rppt@kernel.org Signed-off-by: Mike Rapoport Cc: Baoquan He Cc: Borislav Petkov Cc: David Hildenbrand Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: Mel Gorman Cc: Michal Hocko Cc: Qian Cai Cc: Thomas Gleixner Cc: Vlastimil Babka Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Merge branch 'stable/for-linus-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb

2020-12-16T21:51:34Z

Pull swiotlb update from Konrad Rzeszutek Wilk: "A generic (but for right now engaged only with AMD SEV) mechanism to adjust a larger size SWIOTLB based on the total memory of the SEV guests which right now require the bounce buffer for interacting with the outside world. Normal knobs (swiotlb=XYZ) still work" * 'stable/for-linus-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb: x86,swiotlb: Adjust SWIOTLB bounce buffer size for SEV guests

x86,swiotlb: Adjust SWIOTLB bounce buffer size for SEV guests

2020-12-11T20:43:41Z

For SEV, all DMA to and from guest has to use shared (un-encrypted) pages. SEV uses SWIOTLB to make this happen without requiring changes to device drivers. However, depending on the workload being run, the default 64MB of it might not be enough and it may run out of buffers to use for DMA, resulting in I/O errors and/or performance degradation for high I/O workloads. Adjust the default size of SWIOTLB for SEV guests using a percentage of the total memory available to guest for the SWIOTLB buffers. Adds a new sev_setup_arch() function which is invoked from setup_arch() and it calls into a new swiotlb generic code function swiotlb_adjust_size() to do the SWIOTLB buffer adjustment. v5 fixed build errors and warnings as Reported-by: kbuild test robot Signed-off-by: Ashish Kalra Co-developed-by: Borislav Petkov Signed-off-by: Borislav Petkov Signed-off-by: Konrad Rzeszutek Wilk

x86/setup: Remove unused MCA variables

2020-10-28T13:58:51Z

Commit bb8187d35f82 ("MCA: delete all remaining traces of microchannel bus support.") removed the remaining traces of Micro Channel Architecture support but one trace remained - three variables in setup.c which have been unused since 2012 at least. Drop them finally. Signed-off-by: Borislav Petkov Link: https://lkml.kernel.org/r/20201021165614.23023-1-bp@alien8.de

Merge tag 'dma-mapping-5.10' of git://git.infradead.org/users/hch/dma-mapping

2020-10-15T21:43:29Z

Pull dma-mapping updates from Christoph Hellwig: - rework the non-coherent DMA allocator - move private definitions out of - lower CMA_ALIGNMENT (Paul Cercueil) - remove the omap1 dma address translation in favor of the common code - make dma-direct aware of multiple dma offset ranges (Jim Quinlan) - support per-node DMA CMA areas (Barry Song) - increase the default seg boundary limit (Nicolin Chen) - misc fixes (Robin Murphy, Thomas Tai, Xu Wang) - various cleanups * tag 'dma-mapping-5.10' of git://git.infradead.org/users/hch/dma-mapping: (63 commits) ARM/ixp4xx: add a missing include of dma-map-ops.h dma-direct: simplify the DMA_ATTR_NO_KERNEL_MAPPING handling dma-direct: factor out a dma_direct_alloc_from_pool helper dma-direct check for highmem pages in dma_direct_alloc_pages dma-mapping: merge into dma-mapping: move large parts of to kernel/dma dma-mapping: move dma-debug.h to kernel/dma/ dma-mapping: remove dma-mapping: merge into dma-contiguous: remove dma_contiguous_set_default dma-contiguous: remove dev_set_cma_area dma-contiguous: remove dma_declare_contiguous dma-mapping: split cma: decrease CMA_ALIGNMENT lower limit to 2 firewire-ohci: use dma_alloc_pages dma-iommu: implement ->alloc_noncoherent dma-mapping: add new {alloc,free}_noncoherent dma_map_ops methods dma-mapping: add a new dma_alloc_pages API dma-mapping: remove dma_cache_sync 53c700: convert to dma_alloc_noncoherent ...