resource: split DEFINE_RES_NAMED_DESC() out of DEFINE_RES_NAMED()

Patch series "resource: Split and use DEFINE_RES*() macros", v2.

Replace open coded variants of DEFINE_RES*() macros.

Note, there

resource: split DEFINE_RES_NAMED_DESC() out of DEFINE_RES_NAMED()

Patch series "resource: Split and use DEFINE_RES*() macros", v2.

Replace open coded variants of DEFINE_RES*() macros.

Note, there are many more possibilities over the kernel and even in
reources.c, however the latter contains not so trivial leftovers. That's
why the examples cover only straightforward conversions.


This patch (of 4):

In some cases it would be useful to supply predefined descriptor of the
resource. For this, introduce DEFINE_RES_NAMED_DESC() macro.

While at it, provide DEFINE_RES() that takes only start, size,
and flags.

Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Andy Shevchenko <[email protected]>
Cc: Ilpo Järvinen <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

resource: Add resource set range and size helpers

Setting the end address for a resource with a given size lacks a helper and
is therefore coded manually unlike the getter side which has a helper fo

resource: Add resource set range and size helpers

Setting the end address for a resource with a given size lacks a helper and
is therefore coded manually unlike the getter side which has a helper for
resource size calculation. Also, almost all callsites that calculate the
end address for a resource also set the start address right before it like
this:

res->start = start_addr;
res->end = res->start + size - 1;

Add resource_set_range(res, start_addr, size) that sets the start address
and calculates the end address to simplify this often repeated fragment.

Also add resource_set_size() for the cases where setting the start address
of the resource is not necessary but mention in its kerneldoc that
resource_set_range() is preferred when setting both addresses.

Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Ilpo Järvinen <[email protected]>
Signed-off-by: Bjorn Helgaas <[email protected]>
Reviewed-by: Jonathan Cameron <[email protected]>

show more ...

resource: Export find_resource_space()

PCI bridge window logic needs to find out in advance to the actual
allocation if there is an empty space big enough to fit the window.

Export find_resource_sp

resource: Export find_resource_space()

PCI bridge window logic needs to find out in advance to the actual
allocation if there is an empty space big enough to fit the window.

Export find_resource_space() for the purpose. Also move the struct
resource_constraint into generic header to be able to use the new
interface.

Link: https://lore.kernel.org/r/[email protected]
Tested-by: Lidong Wang <[email protected]>
Signed-off-by: Ilpo Järvinen <[email protected]>
Signed-off-by: Bjorn Helgaas <[email protected]>
Reviewed-by: Andy Shevchenko <[email protected]>
Reviewed-by: Mika Westerberg <[email protected]>

show more ...

resource: Use typedef for alignf callback

To make it simpler to declare resource constraint alignf callbacks, add
typedef for it and document it.

Suggested-by: Andy Shevchenko <andriy.shevchenko@li

resource: Use typedef for alignf callback

To make it simpler to declare resource constraint alignf callbacks, add
typedef for it and document it.

Suggested-by: Andy Shevchenko <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Tested-by: Lidong Wang <[email protected]>
Signed-off-by: Ilpo Järvinen <[email protected]>
Signed-off-by: Bjorn Helgaas <[email protected]>
Reviewed-by: Andy Shevchenko <[email protected]>
Reviewed-by: Mika Westerberg <[email protected]>

show more ...

resource: add walk_system_ram_res_rev()

This function, being a variant of walk_system_ram_res() introduced in
commit 8c86e70acead ("resource: provide new functions to walk through
resources"), walks

resource: add walk_system_ram_res_rev()

This function, being a variant of walk_system_ram_res() introduced in
commit 8c86e70acead ("resource: provide new functions to walk through
resources"), walks through a list of all the resources of System RAM in
reversed order, i.e., from higher to lower.

It will be used in kexec_file code to load kernel, initrd etc when
preparing kexec reboot.

Link: https://lkml.kernel.org/r/ZVTA6z/06cLnWKUz@MiWiFi-R3L-srv
Signed-off-by: AKASHI Takahiro <[email protected]>
Signed-off-by: Baoquan He <[email protected]>
Cc: Eric Biederman <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

resource: Constify resource crosscheck APIs

Constify APIs: _contains(), _overlaps(), _intersection(), _union().

Signed-off-by: Andy Shevchenko <[email protected]>
Link: https://lore

resource: Constify resource crosscheck APIs

Constify APIs: _contains(), _overlaps(), _intersection(), _union().

Signed-off-by: Andy Shevchenko <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

show more ...

PCI: Allow drivers to request exclusive config regions

PCI config space access from user space has traditionally been
unrestricted with writes being an understood risk for device operation.

Unfortu

PCI: Allow drivers to request exclusive config regions

PCI config space access from user space has traditionally been
unrestricted with writes being an understood risk for device operation.

Unfortunately, device breakage or odd behavior from config writes lacks
indicators that can leave driver writers confused when evaluating
failures. This is especially true with the new PCIe Data Object
Exchange (DOE) mailbox protocol where backdoor shenanigans from user
space through things such as vendor defined protocols may affect device
operation without complete breakage.

A prior proposal restricted read and writes completely.[1] Greg and
Bjorn pointed out that proposal is flawed for a couple of reasons.
First, lspci should always be allowed and should not interfere with any
device operation. Second, setpci is a valuable tool that is sometimes
necessary and it should not be completely restricted.[2] Finally
methods exist for full lock of device access if required.

Even though access should not be restricted it would be nice for driver
writers to be able to flag critical parts of the config space such that
interference from user space can be detected.

Introduce pci_request_config_region_exclusive() to mark exclusive config
regions. Such regions trigger a warning and kernel taint if accessed
via user space.

Create pci_warn_once() to restrict the user from spamming the log.

[1] https://lore.kernel.org/all/161663543465.1867664.5674061943008380442.stgit@dwillia2-desk3.amr.corp.intel.com/
[2] https://lore.kernel.org/all/[email protected]/

Cc: Bjorn Helgaas <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Reviewed-by: Jonathan Cameron <[email protected]>
Suggested-by: Dan Williams <[email protected]>
Signed-off-by: Ira Weiny <[email protected]>
Acked-by: Greg Kroah-Hartman <[email protected]>
Acked-by: Bjorn Helgaas <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Dan Williams <[email protected]>

show more ...

resource: Convert DEFINE_RES_NAMED() to be compound literal

Currently DEFINE_RES_NAMED() can only be used to fill the static data.
In some cases it would be convenient to use it as right value in th

resource: Convert DEFINE_RES_NAMED() to be compound literal

Currently DEFINE_RES_NAMED() can only be used to fill the static data.
In some cases it would be convenient to use it as right value in the
assignment operation. But it can't be done as is, because compiler has
no clue about the data layout. Converting it to be a compound literal
allows the above mentioned usage.

Signed-off-by: Andy Shevchenko <[email protected]>
Reviewed-by: Rafael J. Wysocki <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

show more ...

ACPI: resources: Add wake_capable parameter to acpi_dev_irq_flags

ACPI IRQ/Interrupt resources contain a bit that describes if the
interrupt should wake the system. This change exposes that bit via

ACPI: resources: Add wake_capable parameter to acpi_dev_irq_flags

ACPI IRQ/Interrupt resources contain a bit that describes if the
interrupt should wake the system. This change exposes that bit via
a new IORESOURCE_IRQ_WAKECAPABLE flag. Drivers should check this flag
before arming an IRQ to wake the system.

Signed-off-by: Raul E Rangel <[email protected]>
Reviewed-by: Andy Shevchenko <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>

show more ...

resource: add define macro for register address resources

DEFINE_RES_ macros have been created for the commonly used resource types,
but not IORESOURCE_REG. Add the macro so it can be used in a simi

resource: add define macro for register address resources

DEFINE_RES_ macros have been created for the commonly used resource types,
but not IORESOURCE_REG. Add the macro so it can be used in a similar manner
to all other resource types.

Signed-off-by: Colin Foster <[email protected]>
Reviewed-by: Vladimir Oltean <[email protected]>
Reviewed-by: Andy Shevchenko <[email protected]>
Signed-off-by: Lee Jones <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

show more ...

resource: Introduce alloc_free_mem_region()

The core of devm_request_free_mem_region() is a helper that searches for
free space in iomem_resource and performs __request_region_locked() on
the result

resource: Introduce alloc_free_mem_region()

The core of devm_request_free_mem_region() is a helper that searches for
free space in iomem_resource and performs __request_region_locked() on
the result of that search. The policy choices of the implementation
conform to what CONFIG_DEVICE_PRIVATE users want which is memory that is
immediately marked busy, and a preference to search for the first-fit
free range in descending order from the top of the physical address
space.

CXL has a need for a similar allocator, but with the following tweaks:

1/ Search for free space in ascending order

2/ Search for free space relative to a given CXL window

3/ 'insert' rather than 'request' the new resource given downstream
drivers from the CXL Region driver (like the pmem or dax drivers) are
responsible for request_mem_region() when they activate the memory
range.

Rework __request_free_mem_region() into get_free_mem_region() which
takes a set of GFR_* (Get Free Region) flags to control the allocation
policy (ascending vs descending), and "busy" policy (insert_resource()
vs request_region()).

As part of the consolidation of the legacy GFR_REQUEST_REGION case with
the new default of just inserting a new resource into the free space
some minor cleanups like not checking for NULL before calling
devres_free() (which does its own check) is included.

Suggested-by: Jason Gunthorpe <[email protected]>
Link: https://lore.kernel.org/linux-cxl/[email protected]/
Cc: Matthew Wilcox <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Reviewed-by: Jonathan Cameron <[email protected]>
Link: https://lore.kernel.org/r/165784333333.1758207.13703329337805274043.stgit@dwillia2-xfh.jf.intel.com
Signed-off-by: Dan Williams <[email protected]>

show more ...

cxl/acpi: Track CXL resources in iomem_resource

Recall that CXL capable address ranges, on ACPI platforms, are published
in the CEDT.CFMWS (CXL Early Discovery Table: CXL Fixed Memory Window
Structu

cxl/acpi: Track CXL resources in iomem_resource

Recall that CXL capable address ranges, on ACPI platforms, are published
in the CEDT.CFMWS (CXL Early Discovery Table: CXL Fixed Memory Window
Structures). These windows represent both the actively mapped capacity
and the potential address space that can be dynamically assigned to a
new CXL decode configuration (region / interleave-set).

CXL endpoints like DDR DIMMs can be mapped at any physical address
including 0 and legacy ranges.

There is an expectation and requirement that the /proc/iomem interface
and the iomem_resource tree in the kernel reflect the full set of
platform address ranges. I.e. that every address range that platform
firmware and bus drivers enumerate be reflected as an iomem_resource
entry. The hard requirement to do this for CXL arises from the fact that
facilities like CONFIG_DEVICE_PRIVATE expect to be able to treat empty
iomem_resource ranges as free for software to use as proxy address
space. Without CXL publishing its potential address ranges in
iomem_resource, the CONFIG_DEVICE_PRIVATE mechanism may inadvertently
steal capacity reserved for runtime provisioning of new CXL regions.

So, iomem_resource needs to know about both active and potential CXL
resource ranges. The active CXL resources might already be reflected in
iomem_resource as "System RAM". insert_resource_expand_to_fit() handles
re-parenting "System RAM" underneath a CXL window.

The "_expand_to_fit()" behavior handles cases where a CXL window is not
a strict superset of an existing entry in the iomem_resource tree. The
"_expand_to_fit()" behavior is acceptable from the perspective of
resource allocation. The expansion happens because a conflicting
resource range is already populated, which means the resource boundary
expansion does not result in any additional free CXL address space being
made available. CXL address space allocation is always bounded by the
orginal unexpanded address range.

However, the potential for expansion does mean that something like
walk_iomem_res_desc(IORES_DESC_CXL...) can only return fuzzy answers on
corner case platforms that cause the resource tree to expand a CXL
window resource over a range that is not decoded by CXL. This would be
an odd platform configuration, but if it becomes a problem in practice
the CXL subsytem could just publish an API that returns definitive
answers.

Cc: Andrew Morton <[email protected]>
Cc: David Hildenbrand <[email protected]>
Cc: Jason Gunthorpe <[email protected]>
Cc: Tony Luck <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Reviewed-by: Jonathan Cameron <[email protected]>
Acked-by: Greg Kroah-Hartman <[email protected]>
Link: https://lore.kernel.org/r/165784325943.1758207.5310344844375305118.stgit@dwillia2-xfh.jf.intel.com
Signed-off-by: Dan Williams <[email protected]>

show more ...

kernel/resource: Introduce request_mem_region_muxed()

Support for requesting muxed memory region is implemented but not
currently callable as a macro. Add the request muxed memory
region macro.

MMI

kernel/resource: Introduce request_mem_region_muxed()

Support for requesting muxed memory region is implemented but not
currently callable as a macro. Add the request muxed memory
region macro.

MMIO memory accesses can be synchronized using request_mem_region() which
is already available. This call will return failure if the resource is
busy. The 'muxed' version of this macro will handle a busy resource by
using a wait queue to retry until the resource is available.

Signed-off-by: Terry Bowman <[email protected]>
Reviewed-by: Andy Shevchenko <[email protected]>
Signed-off-by: Wolfram Sang <[email protected]>

show more ...

resource: Prevent irqresource_disabled() from erasing flags

Some Chromebooks use hard-coded interrupts in their ACPI tables.
This is an excerpt as dumped on Relm:

...
Name (_HID, "ELAN0

resource: Prevent irqresource_disabled() from erasing flags

Some Chromebooks use hard-coded interrupts in their ACPI tables.
This is an excerpt as dumped on Relm:

...
Name (_HID, "ELAN0001") // _HID: Hardware ID
Name (_DDN, "Elan Touchscreen ") // _DDN: DOS Device Name
Name (_UID, 0x05) // _UID: Unique ID
Name (ISTP, Zero)
Method (_CRS, 0, NotSerialized) // _CRS: Current Resource Settings
{
Name (BUF0, ResourceTemplate ()
{
I2cSerialBusV2 (0x0010, ControllerInitiated, 0x00061A80,
AddressingMode7Bit, "\\_SB.I2C1",
0x00, ResourceConsumer, , Exclusive,
)
Interrupt (ResourceConsumer, Edge, ActiveLow, Exclusive, ,, )
{
0x000000B8,
}
})
Return (BUF0) /* \_SB_.I2C1.ETSA._CRS.BUF0 */
}
...

This interrupt is hard-coded to 0xB8 = 184 which is too high to be mapped
to IO-APIC, so no triggering information is propagated as acpi_register_gsi()
fails and irqresource_disabled() is issued, which leads to erasing triggering
and polarity information.

Do not overwrite flags as it leads to erasing triggering and polarity
information which might be useful in case of hard-coded interrupts.
This way the information can be read later on even though mapping to
APIC domain failed.

Signed-off-by: Angela Czubak <[email protected]>
[ rjw: Changelog rearrangement ]
Signed-off-by: Rafael J. Wysocki <[email protected]>

show more ...

asm-generic/io.h: Add a non-posted variant of ioremap()

ARM64 currently defaults to posted MMIO (nGnRE), but some devices
require the use of non-posted MMIO (nGnRnE). Introduce a new ioremap()
vari

asm-generic/io.h: Add a non-posted variant of ioremap()

ARM64 currently defaults to posted MMIO (nGnRE), but some devices
require the use of non-posted MMIO (nGnRnE). Introduce a new ioremap()
variant to handle this case. ioremap_np() returns NULL on arches that
do not implement this variant.

sparc64 is the only architecture that needs to be touched directly,
because it includes neither of the generic io.h or iomap.h headers.

This adds the IORESOURCE_MEM_NONPOSTED flag, which maps to this
variant and marks a given resource as requiring non-posted mappings.
This is implemented in the resource system because it is a SoC-level
requirement, so existing drivers do not need special-case code to pick
this ioremap variant.

Then this is implemented in devres by introducing devm_ioremap_np(),
and making devm_ioremap_resource() automatically select this variant
when the resource has the IORESOURCE_MEM_NONPOSTED flag set.

Acked-by: Marc Zyngier <[email protected]>
Signed-off-by: Hector Martin <[email protected]>

show more ...

resource: Move devmem revoke code to resource framework

We want all iomem mmaps to consistently revoke ptes when the kernel
takes over and CONFIG_IO_STRICT_DEVMEM is enabled. This includes the
pci b

resource: Move devmem revoke code to resource framework

We want all iomem mmaps to consistently revoke ptes when the kernel
takes over and CONFIG_IO_STRICT_DEVMEM is enabled. This includes the
pci bar mmaps available through procfs and sysfs, which currently do
not revoke mappings.

To prepare for this, move the code from the /dev/kmem driver to
kernel/resource.c.

During review Jason spotted that barriers are used somewhat
inconsistently. Fix that up while we shuffle this code, since it
doesn't have an actual impact at runtime. Otherwise no semantic and
behavioural changes intended, just code extraction and adjusting
comments and names.

Reviewed-by: Greg Kroah-Hartman <[email protected]>
Signed-off-by: Daniel Vetter <[email protected]>
Cc: Jason Gunthorpe <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Dan Williams <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: John Hubbard <[email protected]>
Cc: Jérôme Glisse <[email protected]>
Cc: Jan Kara <[email protected]>
Cc: Dan Williams <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: Arnd Bergmann <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Daniel Vetter <[email protected]>
Cc: David Hildenbrand <[email protected]>
Cc: "Rafael J. Wysocki" <[email protected]>
Signed-off-by: Daniel Vetter <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]

show more ...

resource: Add irqresource_disabled()

Add a common function to set the fields for a irq resource to disabled,
which mimics what is done in acpi_dev_irqresource_disabled(), with a view
to replace that

resource: Add irqresource_disabled()

Add a common function to set the fields for a irq resource to disabled,
which mimics what is done in acpi_dev_irqresource_disabled(), with a view
to replace that function.

Signed-off-by: John Garry <[email protected]>
Signed-off-by: Marc Zyngier <[email protected]>
Reviewed-by: Rafael J. Wysocki <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

show more ...

resource: Introduce resource_intersection() for overlapping resources

There will be at least one user that can utilize new helper.
Provide the helper for future user and for wider use.

Signed-off-b

resource: Introduce resource_intersection() for overlapping resources

There will be at least one user that can utilize new helper.
Provide the helper for future user and for wider use.

Signed-off-by: Andy Shevchenko <[email protected]>
Reviewed-by: Hanjun Guo <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>

show more ...

resource: Introduce resource_union() for overlapping resources

Some already present users may utilize resource_union() helper.
Provide it for them and for wider use in the future.

Signed-off-by: An

resource: Introduce resource_union() for overlapping resources

Some already present users may utilize resource_union() helper.
Provide it for them and for wider use in the future.

Signed-off-by: Andy Shevchenko <[email protected]>
Reviewed-by: Hanjun Guo <[email protected]>
Tested-by: Hanjun Guo <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>

show more ...

resource: Group resource_overlaps() with other inline helpers

For better maintenance group resource_overlaps() with other inline helpers.
While at it, drop extra parentheses.

Signed-off-by: Andy Sh

resource: Group resource_overlaps() with other inline helpers

For better maintenance group resource_overlaps() with other inline helpers.
While at it, drop extra parentheses.

Signed-off-by: Andy Shevchenko <[email protected]>
Reviewed-by: Hanjun Guo <[email protected]>
Tested-by: Hanjun Guo <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>

show more ...

kernel/resource: make iomem_resource implicit in release_mem_region_adjustable()

"mem" in the name already indicates the root, similar to
release_mem_region() and devm_request_mem_region(). Make it

kernel/resource: make iomem_resource implicit in release_mem_region_adjustable()

"mem" in the name already indicates the root, similar to
release_mem_region() and devm_request_mem_region(). Make it implicit.
The only single caller always passes iomem_resource, other parents are not
applicable.

Suggested-by: Wei Yang <[email protected]>
Signed-off-by: David Hildenbrand <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Reviewed-by: Wei Yang <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Dan Williams <[email protected]>
Cc: Jason Gunthorpe <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Ard Biesheuvel <[email protected]>
Cc: Pankaj Gupta <[email protected]>
Cc: Baoquan He <[email protected]>
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Linus Torvalds <[email protected]>

show more ...

mm/memory_hotplug: MEMHP_MERGE_RESOURCE to specify merging of System RAM resources

Some add_memory*() users add memory in small, contiguous memory blocks.
Examples include virtio-mem, hyper-v balloo

mm/memory_hotplug: MEMHP_MERGE_RESOURCE to specify merging of System RAM resources

Some add_memory*() users add memory in small, contiguous memory blocks.
Examples include virtio-mem, hyper-v balloon, and the XEN balloon.

This can quickly result in a lot of memory resources, whereby the actual
resource boundaries are not of interest (e.g., it might be relevant for
DIMMs, exposed via /proc/iomem to user space). We really want to merge
added resources in this scenario where possible.

Let's provide a flag (MEMHP_MERGE_RESOURCE) to specify that a resource
either created within add_memory*() or passed via add_memory_resource()
shall be marked mergeable and merged with applicable siblings.

To implement that, we need a kernel/resource interface to mark selected
System RAM resources mergeable (IORESOURCE_SYSRAM_MERGEABLE) and trigger
merging.

Note: We really want to merge after the whole operation succeeded, not
directly when adding a resource to the resource tree (it would break
add_memory_resource() and require splitting resources again when the
operation failed - e.g., due to -ENOMEM).

Signed-off-by: David Hildenbrand <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Reviewed-by: Pankaj Gupta <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Dan Williams <[email protected]>
Cc: Jason Gunthorpe <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Ard Biesheuvel <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: "K. Y. Srinivasan" <[email protected]>
Cc: Haiyang Zhang <[email protected]>
Cc: Stephen Hemminger <[email protected]>
Cc: Wei Liu <[email protected]>
Cc: Boris Ostrovsky <[email protected]>
Cc: Juergen Gross <[email protected]>
Cc: Stefano Stabellini <[email protected]>
Cc: Roger Pau Monné <[email protected]>
Cc: Julien Grall <[email protected]>
Cc: Baoquan He <[email protected]>
Cc: Wei Yang <[email protected]>
Cc: Anton Blanchard <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: Christian Borntraeger <[email protected]>
Cc: Dave Jiang <[email protected]>
Cc: Eric Biederman <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Jason Wang <[email protected]>
Cc: Len Brown <[email protected]>
Cc: Leonardo Bras <[email protected]>
Cc: Libor Pechacek <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: "Michael S. Tsirkin" <[email protected]>
Cc: Nathan Lynch <[email protected]>
Cc: "Oliver O'Halloran" <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Pingfan Liu <[email protected]>
Cc: "Rafael J. Wysocki" <[email protected]>
Cc: Vasily Gorbik <[email protected]>
Cc: Vishal Verma <[email protected]>
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Linus Torvalds <[email protected]>

show more ...

kernel/resource: move and rename IORESOURCE_MEM_DRIVER_MANAGED

IORESOURCE_MEM_DRIVER_MANAGED currently uses an unused PnP bit, which is
always set to 0 by hardware. This is far from beautiful (and

kernel/resource: move and rename IORESOURCE_MEM_DRIVER_MANAGED

IORESOURCE_MEM_DRIVER_MANAGED currently uses an unused PnP bit, which is
always set to 0 by hardware. This is far from beautiful (and confusing),
and the bit only applies to SYSRAM. So let's move it out of the
bus-specific (PnP) defined bits.

We'll add another SYSRAM specific bit soon. If we ever need more bits for
other purposes, we can steal some from "desc", or reshuffle/regroup what
we have.

Signed-off-by: David Hildenbrand <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Dan Williams <[email protected]>
Cc: Jason Gunthorpe <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Ard Biesheuvel <[email protected]>
Cc: Pankaj Gupta <[email protected]>
Cc: Baoquan He <[email protected]>
Cc: Wei Yang <[email protected]>
Cc: Eric Biederman <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Anton Blanchard <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: Boris Ostrovsky <[email protected]>
Cc: Christian Borntraeger <[email protected]>
Cc: Dave Jiang <[email protected]>
Cc: Haiyang Zhang <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Jason Wang <[email protected]>
Cc: Juergen Gross <[email protected]>
Cc: Julien Grall <[email protected]>
Cc: "K. Y. Srinivasan" <[email protected]>
Cc: Len Brown <[email protected]>
Cc: Leonardo Bras <[email protected]>
Cc: Libor Pechacek <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: "Michael S. Tsirkin" <[email protected]>
Cc: Nathan Lynch <[email protected]>
Cc: "Oliver O'Halloran" <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Pingfan Liu <[email protected]>
Cc: "Rafael J. Wysocki" <[email protected]>
Cc: Roger Pau Monné <[email protected]>
Cc: Stefano Stabellini <[email protected]>
Cc: Stephen Hemminger <[email protected]>
Cc: Vasily Gorbik <[email protected]>
Cc: Vishal Verma <[email protected]>
Cc: Wei Liu <[email protected]>
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Linus Torvalds <[email protected]>

show more ...

kernel/resource: make release_mem_region_adjustable() never fail

Patch series "selective merging of system ram resources", v4.

Some add_memory*() users add memory in small, contiguous memory blocks

kernel/resource: make release_mem_region_adjustable() never fail

Patch series "selective merging of system ram resources", v4.

Some add_memory*() users add memory in small, contiguous memory blocks.
Examples include virtio-mem, hyper-v balloon, and the XEN balloon.

This can quickly result in a lot of memory resources, whereby the actual
resource boundaries are not of interest (e.g., it might be relevant for
DIMMs, exposed via /proc/iomem to user space). We really want to merge
added resources in this scenario where possible.

Resources are effectively stored in a list-based tree. Having a lot of
resources not only wastes memory, it also makes traversing that tree more
expensive, and makes /proc/iomem explode in size (e.g., requiring
kexec-tools to manually merge resources when creating a kdump header. The
current kexec-tools resource count limit does not allow for more than
~100GB of memory with a memory block size of 128MB on x86-64).

Let's allow to selectively merge system ram resources by specifying a new
flag for add_memory*(). Patch #5 contains a /proc/iomem example. Only
tested with virtio-mem.

This patch (of 8):

Let's make sure splitting a resource on memory hotunplug will never fail.
This will become more relevant once we merge selected System RAM resources
- then, we'll trigger that case more often on memory hotunplug.

In general, this function is already unlikely to fail. When we remove
memory, we free up quite a lot of metadata (memmap, page tables, memory
block device, etc.). The only reason it could really fail would be when
injecting allocation errors.

All other error cases inside release_mem_region_adjustable() seem to be
sanity checks if the function would be abused in different context - let's
add WARN_ON_ONCE() in these cases so we can catch them.

[[email protected]: fix use of ternary condition in release_mem_region_adjustable]
Link: https://lkml.kernel.org/r/[email protected]
Link: https://github.com/ClangBuiltLinux/linux/issues/1159

Signed-off-by: David Hildenbrand <[email protected]>
Signed-off-by: Nathan Chancellor <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Dan Williams <[email protected]>
Cc: Jason Gunthorpe <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Ard Biesheuvel <[email protected]>
Cc: Pankaj Gupta <[email protected]>
Cc: Baoquan He <[email protected]>
Cc: Wei Yang <[email protected]>
Cc: Anton Blanchard <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: Boris Ostrovsky <[email protected]>
Cc: Christian Borntraeger <[email protected]>
Cc: Dave Jiang <[email protected]>
Cc: Eric Biederman <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Haiyang Zhang <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Jason Wang <[email protected]>
Cc: Juergen Gross <[email protected]>
Cc: Julien Grall <[email protected]>
Cc: "K. Y. Srinivasan" <[email protected]>
Cc: Len Brown <[email protected]>
Cc: Leonardo Bras <[email protected]>
Cc: Libor Pechacek <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: "Michael S. Tsirkin" <[email protected]>
Cc: Nathan Lynch <[email protected]>
Cc: "Oliver O'Halloran" <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Pingfan Liu <[email protected]>
Cc: "Rafael J. Wysocki" <[email protected]>
Cc: Roger Pau Monn <[email protected]>
Cc: Stefano Stabellini <[email protected]>
Cc: Stephen Hemminger <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Vasily Gorbik <[email protected]>
Cc: Vishal Verma <[email protected]>
Cc: Wei Liu <[email protected]>
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Linus Torvalds <[email protected]>

show more ...

mm/memory_hotplug: introduce add_memory_driver_managed()

Patch series "mm/memory_hotplug: Interface to add driver-managed system
ram", v4.

kexec (via kexec_load()) can currently not properly handle

mm/memory_hotplug: introduce add_memory_driver_managed()

Patch series "mm/memory_hotplug: Interface to add driver-managed system
ram", v4.

kexec (via kexec_load()) can currently not properly handle memory added
via dax/kmem, and will have similar issues with virtio-mem. kexec-tools
will currently add all memory to the fixed-up initial firmware memmap. In
case of dax/kmem, this means that - in contrast to a proper reboot - how
that persistent memory will be used can no longer be configured by the
kexec'd kernel. In case of virtio-mem it will be harmful, because that
memory might contain inaccessible pieces that require coordination with
hypervisor first.

In both cases, we want to let the driver in the kexec'd kernel handle
detecting and adding the memory, like during an ordinary reboot.
Introduce add_memory_driver_managed(). More on the samentics are in patch
#1.

In the future, we might want to make this behavior configurable for
dax/kmem- either by configuring it in the kernel (which would then also
allow to configure kexec_file_load()) or in kexec-tools by also adding
"System RAM (kmem)" memory from /proc/iomem to the fixed-up initial
firmware memmap.

More on the motivation can be found in [1] and [2].

[1] https://lkml.kernel.org/r/[email protected]
[2] https://lkml.kernel.org/r/[email protected]

This patch (of 3):

Some device drivers rely on memory they managed to not get added to the
initial (firmware) memmap as system RAM - so it's not used as initial
system RAM by the kernel and the driver is under control. While this is
the case during cold boot and after a reboot, kexec is not aware of that
and might add such memory to the initial (firmware) memmap of the kexec
kernel. We need ways to teach kernel and userspace that this system ram
is different.

For example, dax/kmem allows to decide at runtime if persistent memory is
to be used as system ram. Another future user is virtio-mem, which has to
coordinate with its hypervisor to deal with inaccessible parts within
memory resources.

We want to let users in the kernel (esp. kexec) but also user space
(esp. kexec-tools) know that this memory has different semantics and
needs to be handled differently:
1. Don't create entries in /sys/firmware/memmap/
2. Name the memory resource "System RAM ($DRIVER)" (exposed via
/proc/iomem) ($DRIVER might be "kmem", "virtio_mem").
3. Flag the memory resource IORESOURCE_MEM_DRIVER_MANAGED

/sys/firmware/memmap/ [1] represents the "raw firmware-provided memory
map" because "on most architectures that firmware-provided memory map is
modified afterwards by the kernel itself". The primary user is kexec on
x86-64. Since commit d96ae5309165 ("memory-hotplug: create
/sys/firmware/memmap entry for new memory"), we add all hotplugged memory
to that firmware memmap - which makes perfect sense for traditional memory
hotplug on x86-64, where real HW will also add hotplugged DIMMs to the
firmware memmap. We replicate what the "raw firmware-provided memory map"
looks like after hot(un)plug.

To keep things simple, let the user provide the full resource name instead
of only the driver name - this way, we don't have to manually
allocate/craft strings for memory resources. Also use the resource name
to make decisions, to avoid passing additional flags. In case the name
isn't "System RAM", it's special.

We don't have to worry about firmware_map_remove() on the removal path.
If there is no entry, it will simply return with -EINVAL.

We'll adapt dax/kmem in a follow-up patch.

[1] https://www.kernel.org/doc/Documentation/ABI/testing/sysfs-firmware-memmap

Signed-off-by: David Hildenbrand <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Acked-by: Pankaj Gupta <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Pankaj Gupta <[email protected]>
Cc: Wei Yang <[email protected]>
Cc: Baoquan He <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: Eric Biederman <[email protected]>
Cc: Pavel Tatashin <[email protected]>
Cc: Dan Williams <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Linus Torvalds <[email protected]>

show more ...