Commit graph

22 commits

Author SHA1 Message Date
Bjorn Helgaas
2709f0338d Merge branch 'remotes/lorenzo/pci/bridge-emul'
- Make emulated ROM BAR read-only by default (Pali Rohár)

- Make some emulated legacy PCI bits read-only for PCIe devices (Pali
  Rohár)

- Update reserved bits in emulated PCIe Capability (Pali Rohár)

- Allow drivers to emulate different PCIe Capability versions (Pali Rohár)

- Set emulated Capabilities List bit for all PCIe devices, since they must
  have at least a PCIe Capability (Pali Rohár)

* remotes/lorenzo/pci/bridge-emul:
  PCI: pci-bridge-emul: Set PCI_STATUS_CAP_LIST for PCIe device
  PCI: pci-bridge-emul: Correctly set PCIe capabilities
  PCI: pci-bridge-emul: Fix definitions of reserved bits
  PCI: pci-bridge-emul: Properly mark reserved PCIe bits in PCI config space
  PCI: pci-bridge-emul: Make expansion ROM Base Address register read-only
2022-01-13 09:57:51 -06:00
Pali Rohár
3be9d243b2 PCI: pci-bridge-emul: Set PCI_STATUS_CAP_LIST for PCIe device
Since all PCI Express device Functions are required to implement the PCI
Express Capability structure, Capabilities List bit in PCI Status Register
must be hardwired to 1b. Capabilities Pointer register (which is already
set by pci-bride-emul.c driver) is valid only when Capabilities List is set
to 1b.

Link: https://lore.kernel.org/r/20211124155944.1290-7-pali@kernel.org
Fixes: 23a5fba4d9 ("PCI: Introduce PCI bridge emulated config space common logic")
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: stable@vger.kernel.org
2021-12-06 14:12:57 +00:00
Pali Rohár
1f1050c5e1 PCI: pci-bridge-emul: Correctly set PCIe capabilities
Older mvebu hardware provides PCIe Capability structure only in version 1.
New mvebu and aardvark hardware provides it in version 2. So do not force
version to 2 in pci_bridge_emul_init() and rather allow drivers to set
correct version. Drivers need to set version in pcie_conf.cap field without
overwriting PCI_CAP_LIST_ID register. Both drivers (mvebu and aardvark) do
not provide slot support yet, so do not set PCI_EXP_FLAGS_SLOT flag.

Link: https://lore.kernel.org/r/20211124155944.1290-6-pali@kernel.org
Fixes: 23a5fba4d9 ("PCI: Introduce PCI bridge emulated config space common logic")
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: stable@vger.kernel.org
2021-12-06 14:12:57 +00:00
Pali Rohár
12998087d9 PCI: pci-bridge-emul: Fix definitions of reserved bits
Some bits in PCI_EXP registers are reserved for non-root ports. Driver
pci-bridge-emul.c implements PCIe Root Port device therefore it should not
allow setting reserved bits of registers.

Properly define non-reserved bits for all PCI_EXP registers.

Link: https://lore.kernel.org/r/20211124155944.1290-5-pali@kernel.org
Fixes: 23a5fba4d9 ("PCI: Introduce PCI bridge emulated config space common logic")
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: stable@vger.kernel.org
2021-12-06 14:12:57 +00:00
Pali Rohár
7b067ac63a PCI: pci-bridge-emul: Properly mark reserved PCIe bits in PCI config space
Some bits in PCI config space are reserved when device is PCIe. Properly
define behavior of PCI registers for PCIe emulated bridge and ensure that
it would not be possible change these reserved bits.

Link: https://lore.kernel.org/r/20211124155944.1290-3-pali@kernel.org
Fixes: 23a5fba4d9 ("PCI: Introduce PCI bridge emulated config space common logic")
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: stable@vger.kernel.org
2021-12-06 12:18:21 +00:00
Pali Rohár
1c1a3b4d3e PCI: pci-bridge-emul: Make expansion ROM Base Address register read-only
If expansion ROM is unsupported (which is the case of pci-bridge-emul.c
driver) then ROM Base Address register must be implemented as read-only
register that return 0 when read, same as for unused Base Address
registers.

Link: https://lore.kernel.org/r/20211124155944.1290-2-pali@kernel.org
Fixes: 23a5fba4d9 ("PCI: Introduce PCI bridge emulated config space common logic")
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: stable@vger.kernel.org
2021-12-06 12:18:21 +00:00
Pali Rohár
8ea673a8b3 PCI: pci-bridge-emul: Add definitions for missing capabilities registers
pci-bridge-emul driver already allocates buffer for capabilities up to the
PCI_EXP_SLTSTA2 register, but does not define bit access behavior for these
registers. Add these missing definitions.

Link: https://lore.kernel.org/r/20211130172913.9727-3-kabel@kernel.org
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
2021-12-02 09:55:48 +00:00
Pali Rohár
9319230ac1 PCI: pci-bridge-emul: Add description for class_revision field
The current assignment to the class_revision member

  class_revision |= cpu_to_le32(PCI_CLASS_BRIDGE_PCI << 16);

can make the reader think that class is at high 16 bits of the member and
revision at low 16 bits.

In reality, class is at high 24 bits, but the class for PCI Bridge Normal
Decode is PCI_CLASS_BRIDGE_PCI << 8.

Change the assignment and add a comment to make this clearer.

Link: https://lore.kernel.org/r/20211130172913.9727-2-kabel@kernel.org
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
2021-12-02 09:55:48 +00:00
Marek Behún
7a41ae80bd PCI: pci-bridge-emul: Fix emulation of W1C bits
The pci_bridge_emul_conf_write() function correctly clears W1C bits in
cfgspace cache, but it does not inform the underlying implementation
about the clear request: the .write_op() method is given the value with
these bits cleared.

This is wrong if the .write_op() needs to know which bits were requested
to be cleared.

Fix the value to be passed into the .write_op() method to have requested
W1C bits set, so that it can clear them.

Both pci-bridge-emul users (mvebu and aardvark) are compatible with this
change.

Link: https://lore.kernel.org/r/20211028185659.20329-2-kabel@kernel.org
Fixes: 23a5fba4d9 ("PCI: Introduce PCI bridge emulated config space common logic")
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: stable@vger.kernel.org
Cc: Russell King <rmk+kernel@armlinux.org.uk>
2021-10-29 10:25:31 +01:00
Russell King
f8ee579d53 PCI: pci-bridge-emul: Fix array overruns, improve safety
We allow up to PCI_EXP_SLTSTA2 registers to be accessed, but the
pcie_cap_regs_behavior[] array only covers up to PCI_EXP_RTSTA.  Expand
this array to avoid walking off the end of it.

Do the same for pci_regs_behavior for consistency[], and add a
BUILD_BUG_ON() to also check the bridge->conf structure size.

Fixes: 23a5fba4d9 ("PCI: Introduce PCI bridge emulated config space common logic")
Link: https://lore.kernel.org/r/E1l6z9W-0006Re-MQ@rmk-PC.armlinux.org.uk
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Pali Rohár <pali@kernel.org>
2021-02-17 17:25:31 -06:00
Pali Rohár
d39ff8ee9f PCI: pci-bridge-emul: Export API functions
It allows kernel modules which are not compiled into kernel image to use
pci-bridge-emul API functions.

Link: https://lore.kernel.org/r/20200907111038.5811-4-pali@kernel.org
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Marek Behún <marek.behun@nic.cz>
2020-09-07 14:27:53 +01:00
Jon Derrick
1446978d56 PCI: pci-bridge-emul: Eliminate the 'reserved' member
Per PCIe 5.0 r1.0, Terms and Acronyms, Page 80:

  Reserved register fields must be read only and must return 0 (all 0's
  for multi-bit fields) when read. Reserved encodings for register and
  packet fields must not be used. Any implementation dependence on a
  Reserved field value or encoding will result in an implementation that
  is not PCI Express-compliant.

This patch ensures reads will return 0 for any bit not in the Read-Only,
Read-Write, or Write-1-to-Clear bitmasks.

Link: https://lore.kernel.org/r/20200511162117.6674-5-jonathan.derrick@intel.com
Signed-off-by: Jon Derrick <jonathan.derrick@intel.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Rob Herring <robh@kernel.org>
2020-05-22 12:39:35 +01:00
Jon Derrick
2960865127 PCI: pci-bridge-emul: Update for PCIe 5.0 r1.0
Add missing bits from PCIe 4.0 and updates for PCIe 5.0 r1.0.

PCIe 4.0:
Device Status bit 6 - W1C - Emergency Power Reduction Detected
Link Control bits 15:14 - RW - DRS Signaling Control
Slot Control bit 13 - RW - Auto Slow Power Limit Disable

PCIe 5.0:
Slot Control bit 14 - RW - In-Band PD Disable

Link: https://lore.kernel.org/r/20200511162117.6674-4-jonathan.derrick@intel.com
Signed-off-by: Jon Derrick <jonathan.derrick@intel.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Rob Herring <robh@kernel.org>
2020-05-22 12:39:35 +01:00
Jon Derrick
f61959b6e2 PCI: pci-bridge-emul: Fix Root Cap/Status comment
The upper 16-bits of Root Control contain the Root Capabilities
register. The code instead describes the Root Status register in the
upper 16-bits, although it uses the correct bit definition for Root
Capabilities, and for Root Status in the next definition.

Fix this comment and add a comment describing the Root Status register.

Link: https://lore.kernel.org/r/20200511162117.6674-3-jonathan.derrick@intel.com
Signed-off-by: Jon Derrick <jonathan.derrick@intel.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Rob Herring <robh@kernel.org>
2020-05-22 12:39:35 +01:00
Jon Derrick
c88d191817 PCI: pci-bridge-emul: Fix PCIe bit conflicts
This patch fixes two bit conflicts in the pci-bridge-emul driver:

1. Bit 3 of Device Status (19 of Device Control) is marked as both
   Write-1-to-Clear and Read-Only. It should be Write-1-to-Clear.
   The Read-Only and Reserved bitmasks are shifted by 1 bit due to this
   error.

2. Bit 12 of Slot Control is marked as both Read-Write and Reserved.
   It should be Read-Write.

Link: https://lore.kernel.org/r/20200511162117.6674-2-jonathan.derrick@intel.com
Signed-off-by: Jon Derrick <jonathan.derrick@intel.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Rob Herring <robh@kernel.org>
2020-05-22 12:39:35 +01:00
Heiner Kallweit
75e1fd42e6 PCI: pci-bridge-emul: Use new constant PCI_STATUS_ERROR_BITS
Use new constant PCI_STATUS_ERROR_BITS to simplify the code.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-03-04 14:21:00 -08:00
Grzegorz Jaszczyk
e0d9d30b73 PCI: pci-bridge-emul: Fix big-endian support
Perform conversion to little-endian before every write to configuration
space and convert it back to CPU endianness on reads.

Additionally, initialise every multiple byte field of config space with
the cpu_to_le* macro, which is required since the structure describing
config space of emulated bridge assumes little-endian convention.

Signed-off-by: Grzegorz Jaszczyk <jaz@semihalf.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
2019-10-17 12:42:48 +01:00
Krzysztof Wilczynski
8050f3f664 PCI: Use static const struct, not const static struct
Move the static keyword to the front of declarations of pci_regs_behavior[]
and pcie_cap_regs_behavior[], which resolves compiler warnings when
building with "W=1":

  drivers/pci/pci-bridge-emul.c:41:1: warning: ‘static’ is not at beginning of
  declaration [-Wold-style-declaration]
   const static struct pci_bridge_reg_behavior pci_regs_behavior[] = {
   ^
  drivers/pci/pci-bridge-emul.c:176:1: warning: ‘static’ is not at beginning of
  declaration [-Wold-style-declaration]
   const static struct pci_bridge_reg_behavior pcie_cap_regs_behavior[] = {
   ^

Link: https://lore.kernel.org/r/20190826151436.4672-1-kw@linux.com
Link: https://lore.kernel.org/r/20190828131733.5817-1-kw@linux.com
Signed-off-by: Krzysztof Wilczynski <kw@linux.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
2019-09-05 13:26:46 -05:00
Bjorn Helgaas
f6b6aefee7 PCI: Fix typos and whitespace errors
Fix typos in drivers/pci.  Comment and whitespace changes only.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
2019-07-09 07:24:53 -05:00
Thomas Petazzoni
33776d0596 PCI: pci-bridge-emul: Extend pci_bridge_emul_init() with flags
Depending on the capabilities of the PCI controller/platform, the
PCI-to-PCI bridge emulation behavior might need to be different. For
example, on platforms that use the pci-mvebu code, we currently don't
support prefetchable memory BARs, so the corresponding fields in the
PCI-to-PCI bridge configuration space should be read-only.

To implement this, extend pci_bridge_emul_init() to take a "flags"
argument, with currently one flag supported:

PCI_BRIDGE_EMUL_NO_PREFETCHABLE_BAR

that will make the prefetchable memory base and limit registers
read-only.

The pci-mvebu and pci-aardvark drivers are updated accordingly.

Fixes: 1f08673eef ("PCI: mvebu: Convert to PCI emulated bridge config space")
Reported-by: Luís Mendes <luis.p.mendes@gmail.com>
Reported-by: Leigh Brown <leigh@solinno.co.uk>
Tested-by: Leigh Brown <leigh@solinno.co.uk>
Tested-by: Luis Mendes <luis.p.mendes@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: stable@vger.kernel.org
Cc: Luís Mendes <luis.p.mendes@gmail.com>
Cc: Leigh Brown <leigh@solinno.co.uk>
2019-02-22 10:51:14 +00:00
Thomas Petazzoni
59f81c35e0 PCI: pci-bridge-emul: Create per-bridge copy of register behavior
The behavior of the different registers of the PCI-to-PCI bridge is
currently encoded in two global arrays, shared by all instances of
PCI-to-PCI bridge emulation.

However, we will need to tweak the behavior on a per-bridge basis, to
accommodate for different capabilities of the platforms where this
code is used. In preparation for this, create a per-bridge copy of the
register behavior arrays, so that they can later be tweaked on a
per-bridge basis.

Fixes: 1f08673eef ("PCI: mvebu: Convert to PCI emulated bridge config space")
Reported-by: Luís Mendes <luis.p.mendes@gmail.com>
Reported-by: Leigh Brown <leigh@solinno.co.uk>
Tested-by: Leigh Brown <leigh@solinno.co.uk>
Tested-by: Luis Mendes <luis.p.mendes@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: stable@vger.kernel.org
Cc: Luís Mendes <luis.p.mendes@gmail.com>
Cc: Leigh Brown <leigh@solinno.co.uk>
2019-02-22 10:47:30 +00:00
Thomas Petazzoni
23a5fba4d9 PCI: Introduce PCI bridge emulated config space common logic
Some PCI host controllers do not expose a configuration space for the
root port PCI bridge. Due to this, the Marvell Armada 370/38x/XP PCI
controller driver (pci-mvebu) emulates a root port PCI bridge
configuration space, and uses that to (among other things) dynamically
create the memory windows that correspond to the PCI MEM and I/O
regions.

Since we now need to add a very similar logic for the Marvell Armada
37xx PCI controller driver (pci-aardvark), instead of duplicating the
code, we create in this commit a common logic called pci-bridge-emul.

The idea of this logic is to emulate a root port PCI bridge
configuration space by providing configuration space read/write
operations, and faking behind the scenes the configuration space of a
PCI bridge. A PCI host controller driver simply has to call
pci_bridge_emul_conf_read() and pci_bridge_emul_conf_write() to
read/write the configuration space of the bridge.

By default, the PCI bridge configuration space is simply emulated by a
chunk of memory, but the PCI host controller can override the behavior
of the read and write operations on a per-register basis to do
additional actions if needed. We take care of complying with the
behavior of the PCI configuration space registers in terms of bits
that are read-write, read-only, reserved and write-1-to-clear.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Russell King <rmk+kernel@armlinux.org.uk>
2018-10-18 17:50:19 +01:00