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Commit 7b6e7ba8 authored by David Daney's avatar David Daney Committed by Bjorn Helgaas
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PCI: thunder: Add driver for ThunderX-pass{1,2} on-chip devices 



The cavium,pci-thunder-ecam devices are exactly ECAM-based PCI root
complexes.  These root complexes (loosely referred to as ECAM units in the
hardware manuals) are used to access the Thunder on-chip devices.  They
are special in that all the BARs on devices behind these root complexes are
at fixed addresses.

Add a driver for these devices that synthesizes Enhanced Allocation (EA)
capability entries for each BAR.

Since this EA synthesis is needed for exactly two chip models, we can hard-
code some assumptions about the device topology and the layout of the
config space of specific DEVFNs in the driver.

[bhelgaas: changelog, whitespace]
Signed-off-by: default avatarDavid Daney <david.daney@cavium.com>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Acked-by: default avatarRob Herring <robh@kernel.org>
parent f12b76e5

Documentation/devicetree/bindings/pci/pci-thunder-ecam.txt

0 → 100644
+30 −0
Original line number Diff line number Diff line 
* ThunderX PCI host controller for pass-1.x silicon



Firmware-initialized PCI host controller to on-chip devices found on

some Cavium ThunderX processors.  These devices have ECAM-based config

access, but the BARs are all at fixed addresses.  We handle the fixed

addresses by synthesizing Enhanced Allocation (EA) capabilities for

these devices.



The properties and their meanings are identical to those described in

host-generic-pci.txt except as listed below.



Properties of the host controller node that differ from

host-generic-pci.txt:



- compatible     : Must be "cavium,pci-host-thunder-ecam"



Example:



	pcie@84b000000000 {

		compatible = "cavium,pci-host-thunder-ecam";

		device_type = "pci";

		msi-parent = <&its>;

		msi-map = <0 &its 0x30000 0x10000>;

		bus-range = <0 31>;

		#size-cells = <2>;

		#address-cells = <3>;

		#stream-id-cells = <1>;

		reg = <0x84b0 0x00000000 0 0x02000000>;  /* Configuration space */

		ranges = <0x03000000 0x8180 0x00000000 0x8180 0x00000000 0x80 0x00000000>; /* mem ranges */

	};

drivers/pci/host/Kconfig

+7 −0
Original line number Diff line number Diff line
@@ -202,4 +202,11 @@ config PCI_HOST_THUNDER_PEM 
	help

	  Say Y here if you want PCIe support for CN88XX Cavium Thunder SoCs.



config PCI_HOST_THUNDER_ECAM

	bool "Cavium Thunder ECAM controller to on-chip devices on pass-1.x silicon"

	depends on OF && ARM64

	select PCI_HOST_COMMON

	help

	  Say Y here if you want ECAM support for CN88XX-Pass-1.x Cavium Thunder SoCs.



endmenu

drivers/pci/host/Makefile

+1 −0
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@@ -23,4 +23,5 @@ obj-$(CONFIG_PCIE_ALTERA) += pcie-altera.o 
obj-$(CONFIG_PCIE_ALTERA_MSI) += pcie-altera-msi.o

obj-$(CONFIG_PCI_HISI) += pcie-hisi.o

obj-$(CONFIG_PCIE_QCOM) += pcie-qcom.o

obj-$(CONFIG_PCI_HOST_THUNDER_ECAM) += pci-thunder-ecam.o

obj-$(CONFIG_PCI_HOST_THUNDER_PEM) += pci-thunder-pem.o

drivers/pci/host/pci-thunder-ecam.c

0 → 100644
+403 −0
Original line number Diff line number Diff line 
/*

 * This file is subject to the terms and conditions of the GNU General Public

 * License.  See the file "COPYING" in the main directory of this archive

 * for more details.

 *

 * Copyright (C) 2015, 2016 Cavium, Inc.

 */



#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/ioport.h>

#include <linux/of_pci.h>

#include <linux/of.h>

#include <linux/platform_device.h>



#include "pci-host-common.h"



/* Mapping is standard ECAM */

static void __iomem *thunder_ecam_map_bus(struct pci_bus *bus,

					  unsigned int devfn,

					  int where)

{

	struct gen_pci *pci = bus->sysdata;

	resource_size_t idx = bus->number - pci->cfg.bus_range->start;



	return pci->cfg.win[idx] + ((devfn << 12) | where);

}



static void set_val(u32 v, int where, int size, u32 *val)

{

	int shift = (where & 3) * 8;



	pr_debug("set_val %04x: %08x\n", (unsigned)(where & ~3), v);

	v >>= shift;

	if (size == 1)

		v &= 0xff;

	else if (size == 2)

		v &= 0xffff;

	*val = v;

}



static int handle_ea_bar(u32 e0, int bar, struct pci_bus *bus,

			 unsigned int devfn, int where, int size, u32 *val)

{

	void __iomem *addr;

	u32 v;



	/* Entries are 16-byte aligned; bits[2,3] select word in entry */

	int where_a = where & 0xc;



	if (where_a == 0) {

		set_val(e0, where, size, val);

		return PCIBIOS_SUCCESSFUL;

	}

	if (where_a == 0x4) {

		addr = bus->ops->map_bus(bus, devfn, bar); /* BAR 0 */

		if (!addr) {

			*val = ~0;

			return PCIBIOS_DEVICE_NOT_FOUND;

		}

		v = readl(addr);

		v &= ~0xf;

		v |= 2; /* EA entry-1. Base-L */

		set_val(v, where, size, val);

		return PCIBIOS_SUCCESSFUL;

	}

	if (where_a == 0x8) {

		u32 barl_orig;

		u32 barl_rb;



		addr = bus->ops->map_bus(bus, devfn, bar); /* BAR 0 */

		if (!addr) {

			*val = ~0;

			return PCIBIOS_DEVICE_NOT_FOUND;

		}

		barl_orig = readl(addr + 0);

		writel(0xffffffff, addr + 0);

		barl_rb = readl(addr + 0);

		writel(barl_orig, addr + 0);

		/* zeros in unsettable bits */

		v = ~barl_rb & ~3;

		v |= 0xc; /* EA entry-2. Offset-L */

		set_val(v, where, size, val);

		return PCIBIOS_SUCCESSFUL;

	}

	if (where_a == 0xc) {

		addr = bus->ops->map_bus(bus, devfn, bar + 4); /* BAR 1 */

		if (!addr) {

			*val = ~0;

			return PCIBIOS_DEVICE_NOT_FOUND;

		}

		v = readl(addr); /* EA entry-3. Base-H */

		set_val(v, where, size, val);

		return PCIBIOS_SUCCESSFUL;

	}

	return PCIBIOS_DEVICE_NOT_FOUND;

}



static int thunder_ecam_p2_config_read(struct pci_bus *bus, unsigned int devfn,

				       int where, int size, u32 *val)

{

	struct gen_pci *pci = bus->sysdata;

	int where_a = where & ~3;

	void __iomem *addr;

	u32 node_bits;

	u32 v;



	/* EA Base[63:32] may be missing some bits ... */

	switch (where_a) {

	case 0xa8:

	case 0xbc:

	case 0xd0:

	case 0xe4:

		break;

	default:

		return pci_generic_config_read(bus, devfn, where, size, val);

	}



	addr = bus->ops->map_bus(bus, devfn, where_a);

	if (!addr) {

		*val = ~0;

		return PCIBIOS_DEVICE_NOT_FOUND;

	}



	v = readl(addr);



	/*

	 * Bit 44 of the 64-bit Base must match the same bit in

	 * the config space access window.  Since we are working with

	 * the high-order 32 bits, shift everything down by 32 bits.

	 */

	node_bits = (pci->cfg.res.start >> 32) & (1 << 12);



	v |= node_bits;

	set_val(v, where, size, val);



	return PCIBIOS_SUCCESSFUL;

}



static int thunder_ecam_config_read(struct pci_bus *bus, unsigned int devfn,

				    int where, int size, u32 *val)

{

	u32 v;

	u32 vendor_device;

	u32 class_rev;

	void __iomem *addr;

	int cfg_type;

	int where_a = where & ~3;



	addr = bus->ops->map_bus(bus, devfn, 0xc);

	if (!addr) {

		*val = ~0;

		return PCIBIOS_DEVICE_NOT_FOUND;

	}



	v = readl(addr);



	/* Check for non type-00 header */

	cfg_type = (v >> 16) & 0x7f;



	addr = bus->ops->map_bus(bus, devfn, 8);

	if (!addr) {

		*val = ~0;

		return PCIBIOS_DEVICE_NOT_FOUND;

	}



	class_rev = readl(addr);

	if (class_rev == 0xffffffff)

		goto no_emulation;



	if ((class_rev & 0xff) >= 8) {

		/* Pass-2 handling */

		if (cfg_type)

			goto no_emulation;

		return thunder_ecam_p2_config_read(bus, devfn, where,

						   size, val);

	}



	/*

	 * All BARs have fixed addresses specified by the EA

	 * capability; they must return zero on read.

	 */

	if (cfg_type == 0 &&

	    ((where >= 0x10 && where < 0x2c) ||

	     (where >= 0x1a4 && where < 0x1bc))) {

		/* BAR or SR-IOV BAR */

		*val = 0;

		return PCIBIOS_SUCCESSFUL;

	}



	addr = bus->ops->map_bus(bus, devfn, 0);

	if (!addr) {

		*val = ~0;

		return PCIBIOS_DEVICE_NOT_FOUND;

	}



	vendor_device = readl(addr);

	if (vendor_device == 0xffffffff)

		goto no_emulation;



	pr_debug("%04x:%04x - Fix pass#: %08x, where: %03x, devfn: %03x\n",

		 vendor_device & 0xffff, vendor_device >> 16, class_rev,

		 (unsigned) where, devfn);



	/* Check for non type-00 header */

	if (cfg_type == 0) {

		bool has_msix;

		bool is_nic = (vendor_device == 0xa01e177d);

		bool is_tns = (vendor_device == 0xa01f177d);



		addr = bus->ops->map_bus(bus, devfn, 0x70);

		if (!addr) {

			*val = ~0;

			return PCIBIOS_DEVICE_NOT_FOUND;

		}

		/* E_CAP */

		v = readl(addr);

		has_msix = (v & 0xff00) != 0;



		if (!has_msix && where_a == 0x70) {

			v |= 0xbc00; /* next capability is EA at 0xbc */

			set_val(v, where, size, val);

			return PCIBIOS_SUCCESSFUL;

		}

		if (where_a == 0xb0) {

			addr = bus->ops->map_bus(bus, devfn, where_a);

			if (!addr) {

				*val = ~0;

				return PCIBIOS_DEVICE_NOT_FOUND;

			}

			v = readl(addr);

			if (v & 0xff00)

				pr_err("Bad MSIX cap header: %08x\n", v);

			v |= 0xbc00; /* next capability is EA at 0xbc */

			set_val(v, where, size, val);

			return PCIBIOS_SUCCESSFUL;

		}

		if (where_a == 0xbc) {

			if (is_nic)

				v = 0x40014; /* EA last in chain, 4 entries */

			else if (is_tns)

				v = 0x30014; /* EA last in chain, 3 entries */

			else if (has_msix)

				v = 0x20014; /* EA last in chain, 2 entries */

			else

				v = 0x10014; /* EA last in chain, 1 entry */

			set_val(v, where, size, val);

			return PCIBIOS_SUCCESSFUL;

		}

		if (where_a >= 0xc0 && where_a < 0xd0)

			/* EA entry-0. PP=0, BAR0 Size:3 */

			return handle_ea_bar(0x80ff0003,

					     0x10, bus, devfn, where,

					     size, val);

		if (where_a >= 0xd0 && where_a < 0xe0 && has_msix)

			 /* EA entry-1. PP=0, BAR4 Size:3 */

			return handle_ea_bar(0x80ff0043,

					     0x20, bus, devfn, where,

					     size, val);

		if (where_a >= 0xe0 && where_a < 0xf0 && is_tns)

			/* EA entry-2. PP=0, BAR2, Size:3 */

			return handle_ea_bar(0x80ff0023,

					     0x18, bus, devfn, where,

					     size, val);

		if (where_a >= 0xe0 && where_a < 0xf0 && is_nic)

			/* EA entry-2. PP=4, VF_BAR0 (9), Size:3 */

			return handle_ea_bar(0x80ff0493,

					     0x1a4, bus, devfn, where,

					     size, val);

		if (where_a >= 0xf0 && where_a < 0x100 && is_nic)

			/* EA entry-3. PP=4, VF_BAR4 (d), Size:3 */

			return handle_ea_bar(0x80ff04d3,

					     0x1b4, bus, devfn, where,

					     size, val);

	} else if (cfg_type == 1) {

		bool is_rsl_bridge = devfn == 0x08;

		bool is_rad_bridge = devfn == 0xa0;

		bool is_zip_bridge = devfn == 0xa8;

		bool is_dfa_bridge = devfn == 0xb0;

		bool is_nic_bridge = devfn == 0x10;



		if (where_a == 0x70) {

			addr = bus->ops->map_bus(bus, devfn, where_a);

			if (!addr) {

				*val = ~0;

				return PCIBIOS_DEVICE_NOT_FOUND;

			}

			v = readl(addr);

			if (v & 0xff00)

				pr_err("Bad PCIe cap header: %08x\n", v);

			v |= 0xbc00; /* next capability is EA at 0xbc */

			set_val(v, where, size, val);

			return PCIBIOS_SUCCESSFUL;

		}

		if (where_a == 0xbc) {

			if (is_nic_bridge)

				v = 0x10014; /* EA last in chain, 1 entry */

			else

				v = 0x00014; /* EA last in chain, no entries */

			set_val(v, where, size, val);

			return PCIBIOS_SUCCESSFUL;

		}

		if (where_a == 0xc0) {

			if (is_rsl_bridge || is_nic_bridge)

				v = 0x0101; /* subordinate:secondary = 1:1 */

			else if (is_rad_bridge)

				v = 0x0202; /* subordinate:secondary = 2:2 */

			else if (is_zip_bridge)

				v = 0x0303; /* subordinate:secondary = 3:3 */

			else if (is_dfa_bridge)

				v = 0x0404; /* subordinate:secondary = 4:4 */

			set_val(v, where, size, val);

			return PCIBIOS_SUCCESSFUL;

		}

		if (where_a == 0xc4 && is_nic_bridge) {

			/* Enabled, not-Write, SP=ff, PP=05, BEI=6, ES=4 */

			v = 0x80ff0564;

			set_val(v, where, size, val);

			return PCIBIOS_SUCCESSFUL;

		}

		if (where_a == 0xc8 && is_nic_bridge) {

			v = 0x00000002; /* Base-L 64-bit */

			set_val(v, where, size, val);

			return PCIBIOS_SUCCESSFUL;

		}

		if (where_a == 0xcc && is_nic_bridge) {

			v = 0xfffffffe; /* MaxOffset-L 64-bit */

			set_val(v, where, size, val);

			return PCIBIOS_SUCCESSFUL;

		}

		if (where_a == 0xd0 && is_nic_bridge) {

			v = 0x00008430; /* NIC Base-H */

			set_val(v, where, size, val);

			return PCIBIOS_SUCCESSFUL;

		}

		if (where_a == 0xd4 && is_nic_bridge) {

			v = 0x0000000f; /* MaxOffset-H */

			set_val(v, where, size, val);

			return PCIBIOS_SUCCESSFUL;

		}

	}

no_emulation:

	return pci_generic_config_read(bus, devfn, where, size, val);

}



static int thunder_ecam_config_write(struct pci_bus *bus, unsigned int devfn,

				     int where, int size, u32 val)

{

	/*

	 * All BARs have fixed addresses; ignore BAR writes so they

	 * don't get corrupted.

	 */

	if ((where >= 0x10 && where < 0x2c) ||

	    (where >= 0x1a4 && where < 0x1bc))

		/* BAR or SR-IOV BAR */

		return PCIBIOS_SUCCESSFUL;



	return pci_generic_config_write(bus, devfn, where, size, val);

}



static struct gen_pci_cfg_bus_ops thunder_ecam_bus_ops = {

	.bus_shift	= 20,

	.ops		= {

		.map_bus        = thunder_ecam_map_bus,

		.read           = thunder_ecam_config_read,

		.write          = thunder_ecam_config_write,

	}

};



static const struct of_device_id thunder_ecam_of_match[] = {

	{ .compatible = "cavium,pci-host-thunder-ecam",

	  .data = &thunder_ecam_bus_ops },



	{ },

};

MODULE_DEVICE_TABLE(of, thunder_ecam_of_match);



static int thunder_ecam_probe(struct platform_device *pdev)

{

	struct device *dev = &pdev->dev;

	const struct of_device_id *of_id;

	struct gen_pci *pci = devm_kzalloc(dev, sizeof(*pci), GFP_KERNEL);



	if (!pci)

		return -ENOMEM;



	of_id = of_match_node(thunder_ecam_of_match, dev->of_node);

	pci->cfg.ops = (struct gen_pci_cfg_bus_ops *)of_id->data;



	return pci_host_common_probe(pdev, pci);

}



static struct platform_driver thunder_ecam_driver = {

	.driver = {

		.name = KBUILD_MODNAME,

		.of_match_table = thunder_ecam_of_match,

	},

	.probe = thunder_ecam_probe,

};

module_platform_driver(thunder_ecam_driver);



MODULE_DESCRIPTION("Thunder ECAM PCI host driver");

MODULE_LICENSE("GPL v2");