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path: root/drivers/pci/pci-bridge-emul.c
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2020-05-22PCI: pci-bridge-emul: Eliminate the 'reserved' memberJon Derrick
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>
2020-05-22PCI: pci-bridge-emul: Update for PCIe 5.0 r1.0Jon Derrick
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>
2020-05-22PCI: pci-bridge-emul: Fix Root Cap/Status commentJon Derrick
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>
2020-05-22PCI: pci-bridge-emul: Fix PCIe bit conflictsJon Derrick
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>
2020-03-04PCI: pci-bridge-emul: Use new constant PCI_STATUS_ERROR_BITSHeiner Kallweit
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>
2019-10-17PCI: pci-bridge-emul: Fix big-endian supportGrzegorz Jaszczyk
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>
2019-09-05PCI: Use static const struct, not const static structKrzysztof Wilczynski
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>
2019-07-09PCI: Fix typos and whitespace errorsBjorn Helgaas
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>
2019-02-22PCI: pci-bridge-emul: Extend pci_bridge_emul_init() with flagsThomas Petazzoni
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: 1f08673eef123 ("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>
2019-02-22PCI: pci-bridge-emul: Create per-bridge copy of register behaviorThomas Petazzoni
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: 1f08673eef123 ("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>
2018-10-18PCI: Introduce PCI bridge emulated config space common logicThomas Petazzoni
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>