Two changes were made in link retraining logic independent of each other.
The commit e7e3975636 ("PCI/ASPM: Avoid link retraining race") added a
check to pcie_retrain_link() to ensure no Link Training is currently active
to address the Implementation Note in PCIe r6.1 sec 7.5.3.7. At that time
pcie_wait_for_retrain() only checked for the Link Training (LT) bit being
cleared.
The commit 680e9c47a2 ("PCI: Add support for polling DLLLA to
pcie_retrain_link()") generalized pcie_wait_for_retrain() into
pcie_wait_for_link_status() which can wait either for LT or the Data Link
Layer Link Active (DLLLA) bit with 'use_lt' argument and supporting waiting
for either cleared or set using 'active' argument.
In the merge commit 1abb473903 ("Merge branch 'pci/enumeration'"), those
two divergent branches converged. The merge changed LT bit checking added
in the commit e7e3975636 ("PCI/ASPM: Avoid link retraining race") to now
wait for completion of any ongoing Link Training using DLLLA bit being set
if 'use_lt' is false.
When 'use_lt' is false, the pseudo-code steps of what occurs in
pcie_retrain_link():
1. Wait for DLLLA==1
2. Trigger link to retrain
3. Wait for DLLLA==1
Step 3 waits for the link to come up from the retraining triggered by Step
2. As Step 1 is supposed to wait for any ongoing retraining to end, using
DLLLA also for it does not make sense because link training being active is
still indicated using LT bit, not with DLLLA.
Correct the pcie_wait_for_link_status() parameters in Step 1 to only wait
for LT==0 to ensure there is no ongoing Link Training.
This only impacts the Target Speed quirk, which is the only case where
waiting for DLLLA bit is used. It currently works in the problematic case
by means of link training getting initiated by hardware repeatedly and
respecting the new link parameters set by the caller, which then make
training succeed and bring the link up, setting DLLLA and causing
pcie_wait_for_link_status() to return success. We are not supposed to rely
on luck and need to make sure that LT transitioned through the inactive
state though before we initiate link training by hand via RL (Retrain Link)
bit.
Fixes: 1abb473903 ("Merge branch 'pci/enumeration'")
Link: https://lore.kernel.org/r/20240423130820.43824-1-ilpo.jarvinen@linux.intel.com
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
We enumerate devices by attempting config reads to the Vendor ID of each
possible device. On conventional PCI, if no device responds, the read
terminates with a Master Abort (PCI r3.0, sec 6.1). On PCIe, the config
read is terminated as an Unsupported Request (PCIe r6.0, sec 2.3.2,
7.5.1.3.7). In either case, if the read addressed a device below a bridge,
it is logged by setting "Received Master Abort" in the bridge Secondary
Status register.
Clear any errors logged in the Secondary Status register after enumeration.
Link: https://lore.kernel.org/r/20240116143258.483235-1-vidyas@nvidia.com
Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
[bhelgaas: simplify commit log]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Pull EFI fixes from Ard Biesheuvel:
- Fix logic that is supposed to prevent placement of the kernel image
below LOAD_PHYSICAL_ADDR
- Use the firmware stack in the EFI stub when running in mixed mode
- Clear BSS only once when using mixed mode
- Check efi.get_variable() function pointer for NULL before trying to
call it
* tag 'efi-fixes-for-v6.9-2' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi:
efi: fix panic in kdump kernel
x86/efistub: Don't clear BSS twice in mixed mode
x86/efistub: Call mixed mode boot services on the firmware's stack
efi/libstub: fix efi_random_alloc() to allocate memory at alloc_min or higher address
Pull x86 fixes from Thomas Gleixner:
- Ensure that the encryption mask at boot is properly propagated on
5-level page tables, otherwise the PGD entry is incorrectly set to
non-encrypted, which causes system crashes during boot.
- Undo the deferred 5-level page table setup as it cannot work with
memory encryption enabled.
- Prevent inconsistent XFD state on CPU hotplug, where the MSR is reset
to the default value but the cached variable is not, so subsequent
comparisons might yield the wrong result and as a consequence the
result prevents updating the MSR.
- Register the local APIC address only once in the MPPARSE enumeration
to prevent triggering the related WARN_ONs() in the APIC and topology
code.
- Handle the case where no APIC is found gracefully by registering a
fake APIC in the topology code. That makes all related topology
functions work correctly and does not affect the actual APIC driver
code at all.
- Don't evaluate logical IDs during early boot as the local APIC IDs
are not yet enumerated and the invoked function returns an error
code. Nothing requires the logical IDs before the final CPUID
enumeration takes place, which happens after the enumeration.
- Cure the fallout of the per CPU rework on UP which misplaced the
copying of boot_cpu_data to per CPU data so that the final update to
boot_cpu_data got lost which caused inconsistent state and boot
crashes.
- Use copy_from_kernel_nofault() in the kprobes setup as there is no
guarantee that the address can be safely accessed.
- Reorder struct members in struct saved_context to work around another
kmemleak false positive
- Remove the buggy code which tries to update the E820 kexec table for
setup_data as that is never passed to the kexec kernel.
- Update the resource control documentation to use the proper units.
- Fix a Kconfig warning observed with tinyconfig
* tag 'x86-urgent-2024-03-24' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/boot/64: Move 5-level paging global variable assignments back
x86/boot/64: Apply encryption mask to 5-level pagetable update
x86/cpu: Add model number for another Intel Arrow Lake mobile processor
x86/fpu: Keep xfd_state in sync with MSR_IA32_XFD
Documentation/x86: Document that resctrl bandwidth control units are MiB
x86/mpparse: Register APIC address only once
x86/topology: Handle the !APIC case gracefully
x86/topology: Don't evaluate logical IDs during early boot
x86/cpu: Ensure that CPU info updates are propagated on UP
kprobes/x86: Use copy_from_kernel_nofault() to read from unsafe address
x86/pm: Work around false positive kmemleak report in msr_build_context()
x86/kexec: Do not update E820 kexec table for setup_data
x86/config: Fix warning for 'make ARCH=x86_64 tinyconfig'
Pull scheduler doc clarification from Thomas Gleixner:
"A single update for the documentation of the base_slice_ns tunable to
clarify that any value which is less than the tick slice has no effect
because the scheduler tick is not guaranteed to happen within the set
time slice"
* tag 'sched-urgent-2024-03-24' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/doc: Update documentation for base_slice_ns and CONFIG_HZ relation
Pull dma-mapping fixes from Christoph Hellwig:
"This has a set of swiotlb alignment fixes for sometimes very long
standing bugs from Will. We've been discussion them for a while and
they should be solid now"
* tag 'dma-mapping-6.9-2024-03-24' of git://git.infradead.org/users/hch/dma-mapping:
swiotlb: Reinstate page-alignment for mappings >= PAGE_SIZE
iommu/dma: Force swiotlb_max_mapping_size on an untrusted device
swiotlb: Fix alignment checks when both allocation and DMA masks are present
swiotlb: Honour dma_alloc_coherent() alignment in swiotlb_alloc()
swiotlb: Enforce page alignment in swiotlb_alloc()
swiotlb: Fix double-allocation of slots due to broken alignment handling
Check if get_next_variable() is actually valid pointer before
calling it. In kdump kernel this method is set to NULL that causes
panic during the kexec-ed kernel boot.
Tested with QEMU and OVMF firmware.
Fixes: bad267f9e1 ("efi: verify that variable services are supported")
Signed-off-by: Oleksandr Tymoshenko <ovt@google.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Clearing BSS should only be done once, at the very beginning.
efi_pe_entry() is the entrypoint from the firmware, which may not clear
BSS and so it is done explicitly. However, efi_pe_entry() is also used
as an entrypoint by the mixed mode startup code, in which case BSS will
already have been cleared, and doing it again at this point will corrupt
global variables holding the firmware's GDT/IDT and segment selectors.
So make the memset() conditional on whether the EFI stub is running in
native mode.
Fixes: b3810c5a2c ("x86/efistub: Clear decompressor BSS in native EFI entrypoint")
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Normally, the EFI stub calls into the EFI boot services using the stack
that was live when the stub was entered. According to the UEFI spec,
this stack needs to be at least 128k in size - this might seem large but
all asynchronous processing and event handling in EFI runs from the same
stack and so quite a lot of space may be used in practice.
In mixed mode, the situation is a bit different: the bootloader calls
the 32-bit EFI stub entry point, which calls the decompressor's 32-bit
entry point, where the boot stack is set up, using a fixed allocation
of 16k. This stack is still in use when the EFI stub is started in
64-bit mode, and so all calls back into the EFI firmware will be using
the decompressor's limited boot stack.
Due to the placement of the boot stack right after the boot heap, any
stack overruns have gone unnoticed. However, commit
5c4feadb0011983b ("x86/decompressor: Move global symbol references to C code")
moved the definition of the boot heap into C code, and now the boot
stack is placed right at the base of BSS, where any overruns will
corrupt the end of the .data section.
While it would be possible to work around this by increasing the size of
the boot stack, doing so would affect all x86 systems, and mixed mode
systems are a tiny (and shrinking) fraction of the x86 installed base.
So instead, record the firmware stack pointer value when entering from
the 32-bit firmware, and switch to this stack every time a EFI boot
service call is made.
Cc: <stable@kernel.org> # v6.1+
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Commit 63bed96604 ("x86/startup_64: Defer assignment of 5-level paging
global variables") moved assignment of 5-level global variables to later
in the boot in order to avoid having to use RIP relative addressing in
order to set them. However, when running with 5-level paging and SME
active (mem_encrypt=on), the variables are needed as part of the page
table setup needed to encrypt the kernel (using pgd_none(), p4d_offset(),
etc.). Since the variables haven't been set, the page table manipulation
is done as if 4-level paging is active, causing the system to crash on
boot.
While only a subset of the assignments that were moved need to be set
early, move all of the assignments back into check_la57_support() so that
these assignments aren't spread between two locations. Instead of just
reverting the fix, this uses the new RIP_REL_REF() macro when assigning
the variables.
Fixes: 63bed96604 ("x86/startup_64: Defer assignment of 5-level paging global variables")
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/2ca419f4d0de719926fd82353f6751f717590a86.1711122067.git.thomas.lendacky@amd.com
When running with 5-level page tables, the kernel mapping PGD entry is
updated to point to the P4D table. The assignment uses _PAGE_TABLE_NOENC,
which, when SME is active (mem_encrypt=on), results in a page table
entry without the encryption mask set, causing the system to crash on
boot.
Change the assignment to use _PAGE_TABLE instead of _PAGE_TABLE_NOENC so
that the encryption mask is set for the PGD entry.
Fixes: 533568e06b ("x86/boot/64: Use RIP_REL_REF() to access early_top_pgt[]")
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/8f20345cda7dbba2cf748b286e1bc00816fe649a.1711122067.git.thomas.lendacky@amd.com
Commit 672365477a ("x86/fpu: Update XFD state where required") and
commit 8bf26758ca ("x86/fpu: Add XFD state to fpstate") introduced a
per CPU variable xfd_state to keep the MSR_IA32_XFD value cached, in
order to avoid unnecessary writes to the MSR.
On CPU hotplug MSR_IA32_XFD is reset to the init_fpstate.xfd, which
wipes out any stale state. But the per CPU cached xfd value is not
reset, which brings them out of sync.
As a consequence a subsequent xfd_update_state() might fail to update
the MSR which in turn can result in XRSTOR raising a #NM in kernel
space, which crashes the kernel.
To fix this, introduce xfd_set_state() to write xfd_state together
with MSR_IA32_XFD, and use it in all places that set MSR_IA32_XFD.
Fixes: 672365477a ("x86/fpu: Update XFD state where required")
Signed-off-by: Adamos Ttofari <attofari@amazon.de>
Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20240322230439.456571-1-chang.seok.bae@intel.com
Closes: https://lore.kernel.org/lkml/20230511152818.13839-1-attofari@amazon.de
The memory bandwidth software controller uses 2^20 units rather than
10^6. See mbm_bw_count() which computes bandwidth using the "SZ_1M"
Linux define for 0x00100000.
Update the documentation to use MiB when describing this feature.
It's too late to fix the mount option "mba_MBps" as that is now an
established user interface.
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20240322182016.196544-1-tony.luck@intel.com
Pull timer fixes from Thomas Gleixner:
"Two regression fixes for the timer and timer migration code:
- Prevent endless timer requeuing which is caused by two CPUs racing
out of idle. This happens when the last CPU goes idle and therefore
has to ensure to expire the pending global timers and some other
CPU come out of idle at the same time and the other CPU wins the
race and expires the global queue. This causes the last CPU to
chase ghost timers forever and reprogramming it's clockevent device
endlessly.
Cure this by re-evaluating the wakeup time unconditionally.
- The split into local (pinned) and global timers in the timer wheel
caused a regression for NOHZ full as it broke the idle tracking of
global timers. On NOHZ full this prevents an self IPI being sent
which in turn causes the timer to be not programmed and not being
expired on time.
Restore the idle tracking for the global timer base so that the
self IPI condition for NOHZ full is working correctly again"
* tag 'timers-urgent-2024-03-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
timers: Fix removed self-IPI on global timer's enqueue in nohz_full
timers/migration: Fix endless timer requeue after idle interrupts
Pull more clocksource updates from Thomas Gleixner:
"A set of updates for clocksource and clockevent drivers:
- A fix for the prescaler of the ARM global timer where the prescaler
mask define only covered 4 bits while it is actully 8 bits wide.
This obviously restricted the possible range of prescaler
adjustments
- A fix for the RISC-V timer which prevents a timer interrupt being
raised while the timer is initialized
- A set of device tree updates to support new system on chips in
various drivers
- Kernel-doc and other cleanups all over the place"
* tag 'timers-core-2024-03-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
clocksource/drivers/timer-riscv: Clear timer interrupt on timer initialization
dt-bindings: timer: Add support for cadence TTC PWM
clocksource/drivers/arm_global_timer: Simplify prescaler register access
clocksource/drivers/arm_global_timer: Guard against division by zero
clocksource/drivers/arm_global_timer: Make gt_target_rate unsigned long
dt-bindings: timer: add Ralink SoCs system tick counter
clocksource: arm_global_timer: fix non-kernel-doc comment
clocksource/drivers/arm_global_timer: Remove stray tab
clocksource/drivers/arm_global_timer: Fix maximum prescaler value
clocksource/drivers/imx-sysctr: Add i.MX95 support
clocksource/drivers/imx-sysctr: Drop use global variables
dt-bindings: timer: nxp,sysctr-timer: support i.MX95
dt-bindings: timer: renesas: ostm: Document RZ/Five SoC
dt-bindings: timer: renesas,tmu: Document input capture interrupt
clocksource/drivers/ti-32K: Fix misuse of "/**" comment
clocksource/drivers/stm32: Fix all kernel-doc warnings
dt-bindings: timer: exynos4210-mct: Add google,gs101-mct compatible
clocksource/drivers/imx: Fix -Wunused-but-set-variable warning
Pull irq fixes from Thomas Gleixner:
"A series of fixes for the Renesas RZG21 interrupt chip driver to
prevent spurious and misrouted interrupts.
- Ensure that posted writes are flushed in the eoi() callback
- Ensure that interrupts are masked at the chip level when the
trigger type is changed
- Clear the interrupt status register when setting up edge type
trigger modes
- Ensure that the trigger type and routing information is set before
the interrupt is enabled"
* tag 'irq-urgent-2024-03-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
irqchip/renesas-rzg2l: Do not set TIEN and TINT source at the same time
irqchip/renesas-rzg2l: Prevent spurious interrupts when setting trigger type
irqchip/renesas-rzg2l: Rename rzg2l_irq_eoi()
irqchip/renesas-rzg2l: Rename rzg2l_tint_eoi()
irqchip/renesas-rzg2l: Flush posted write in irq_eoi()
Pull core entry fix from Thomas Gleixner:
"A single fix for the generic entry code:
The trace_sys_enter() tracepoint can modify the syscall number via
kprobes or BPF in pt_regs, but that requires that the syscall number
is re-evaluted from pt_regs after the tracepoint.
A seccomp fix in that area removed the re-evaluation so the change
does not take effect as the code just uses the locally cached number.
Restore the original behaviour by re-evaluating the syscall number
after the tracepoint"
* tag 'core-entry-2024-03-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
entry: Respect changes to system call number by trace_sys_enter()
