ntb_hw_epf works just as well when built into the kernel image. Don't
force module build.

Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

Add virtual non-transparent bridge support for Renesas rcar platform

Reviewed-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

The NTB epf host driver assumes the BAR number associated with a memory
window is just incremented from the BAR number associated with MW1. This
seems to have been enough so far but this is not really how the endpoint
side work and the two could easily become mis-aligned.

ntb_epf_mw_to_bar() even assumes that the BAR number is the memory window
index + 2, which means the function only returns a proper result if BAR_2
is associated with MW1.

Instead, fully describe and allow arbitrary NTB BAR mapping.

Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

Use "/*" instead of "/**" for common C comments to prevent warnings
from scripts/kernel-doc.

ntb_hw_epf.c:15: warning: expecting prototype for Host side endpoint driver to implement Non(). Prototype was for NTB_EPF_COMMAND() instead

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Jon Mason <jdmason@kudzu.us>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Allen Hubbe <allenbh@gmail.com>
Cc: ntb@lists.linux.dev
Signed-off-by: Jon Mason <jdmason@kudzu.us>

Remove pci_clear_master to simplify the code,
the bus-mastering is also cleared in do_pci_disable_device,
like this:
./drivers/pci/pci.c:2197
static void do_pci_disable_device(struct pci_dev *dev)
{
	u16 pci_command;

	pci_read_config_word(dev, PCI_COMMAND, &pci_command);
	if (pci_command & PCI_COMMAND_MASTER) {
		pci_command &= ~PCI_COMMAND_MASTER;
		pci_write_config_word(dev, PCI_COMMAND, pci_command);
	}

	pcibios_disable_device(dev);
}.
And dev->is_busmaster is set to 0 in pci_disable_device.

Signed-off-by: Cai Huoqing <cai.huoqing@linux.dev>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

Support the below BAR configuration methods for epf NTB.

BAR 0: config and scratchpad
BAR 2: doorbell
BAR 4: memory map windows

Set difference BAR number information into struct ntb_epf_data. So difference
VID/PID can choose different BAR configurations. There are difference
BAR map method between epf NTB and epf vNTB Endpoint function.

Signed-off-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

Add support for EPF PCI Non-Transparent Bridge (NTB) devices.  This driver
is platform independent and may be used by any platform that has multiple
PCI endpoint instances configured using the pci-epf-ntb driver.  The driver
connnects to the standard NTB subsystem interface. The EPF NTB device has a
configurable number of memory windows (max 4), a configurable number of
doorbells (max 32), and a configurable number of scratch-pad registers.

Link: https://lore.kernel.org/r/20210201195809.7342-16-kishon@ti.com
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>