git: c9a05c072270 - main - Add a PCI driver that follows the Arm DEN0115 spec

From: Andrew Turner <andrew_at_FreeBSD.org>
Date: Mon, 24 Apr 2023 11:34:13 UTC
The branch main has been updated by andrew:

URL: https://cgit.FreeBSD.org/src/commit/?id=c9a05c072270fc0140fccc0c6c0181c4c0b66c62

commit c9a05c072270fc0140fccc0c6c0181c4c0b66c62
Author:     Andrew Turner <andrew@FreeBSD.org>
AuthorDate: 2022-06-04 11:02:47 +0000
Commit:     Andrew Turner <andrew@FreeBSD.org>
CommitDate: 2023-04-24 11:33:50 +0000

    Add a PCI driver that follows the Arm DEN0115 spec
    
    Add a n attachment to the pci_host_generic driver for the Arm DEN0115
    PCI Configuration Space Access Firmware Interface [1]. This can be used
    when PCI controllers need to implement quirks in the PCI root bus.
    To handle this the firmware implements a SMCCC interface the driver can
    use to read and write the configuration register.
    
    This has been tested on a Raspberry Pi 4 booting with EDK2.
    
    [1] https://developer.arm.com/documentation/den0115/latest
    
    Sponsored by:   Arm Ltd
    Differential Revision:  https://reviews.freebsd.org/D39228
---
 sys/conf/files.arm64                   |   1 +
 sys/dev/pci/pci_host_generic_den0115.c | 247 +++++++++++++++++++++++++++++++++
 2 files changed, 248 insertions(+)

diff --git a/sys/conf/files.arm64 b/sys/conf/files.arm64
index 895d29cae818..9218336d154d 100644
--- a/sys/conf/files.arm64
+++ b/sys/conf/files.arm64
@@ -359,6 +359,7 @@ dev/ofw/ofw_pcib.c				optional fdt pci
 dev/pci/controller/pci_n1sdp.c			optional pci_n1sdp acpi
 dev/pci/pci_host_generic.c			optional pci
 dev/pci/pci_host_generic_acpi.c			optional pci acpi
+dev/pci/pci_host_generic_den0115.c		optional pci acpi
 dev/pci/pci_host_generic_fdt.c			optional pci fdt
 dev/pci/pci_dw_mv.c				optional pci fdt
 dev/pci/pci_dw.c				optional pci fdt
diff --git a/sys/dev/pci/pci_host_generic_den0115.c b/sys/dev/pci/pci_host_generic_den0115.c
new file mode 100644
index 000000000000..08cb77cea22c
--- /dev/null
+++ b/sys/dev/pci/pci_host_generic_den0115.c
@@ -0,0 +1,247 @@
+/*-
+ * Copyright (c) 2022 Andrew Turner
+ * Copyright (c) 2023 Arm Ltd
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/bus.h>
+#include <sys/kernel.h>
+#include <sys/module.h>
+#include <sys/rman.h>
+
+#include <contrib/dev/acpica/include/acpi.h>
+#include <contrib/dev/acpica/include/accommon.h>
+
+#include <dev/acpica/acpivar.h>
+#include <dev/acpica/acpi_pcibvar.h>
+
+#include <dev/pci/pcivar.h>
+#include <dev/pci/pcireg.h>
+#include <dev/pci/pcib_private.h>
+#include <dev/pci/pci_host_generic.h>
+#include <dev/pci/pci_host_generic_acpi.h>
+
+#include <dev/psci/psci.h>
+
+#include "pcib_if.h"
+
+static device_probe_t pci_host_acpi_smccc_probe;
+static device_attach_t pci_host_acpi_smccc_attach;
+static pcib_read_config_t pci_host_acpi_smccc_read_config;
+static pcib_write_config_t pci_host_acpi_smccc_write_config;
+
+static int
+pci_host_acpi_smccc_probe(device_t dev)
+{
+	ACPI_DEVICE_INFO *devinfo;
+	struct resource *res;
+	ACPI_HANDLE h;
+	uint32_t smccc_version;
+	int rid, root;
+
+	if (acpi_disabled("pcib") || (h = acpi_get_handle(dev)) == NULL ||
+	    ACPI_FAILURE(AcpiGetObjectInfo(h, &devinfo)))
+		return (ENXIO);
+	root = (devinfo->Flags & ACPI_PCI_ROOT_BRIDGE) != 0;
+	AcpiOsFree(devinfo);
+	if (!root)
+		return (ENXIO);
+
+	/*
+	 * Check we have memory resources. We may have a non-memory
+	 * mapped device, e.g. using the Arm PCI Configuration Space
+	 * Access Firmware Interface (DEN0115).
+	 */
+	res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid, 0);
+	if (res != NULL) {
+		bus_release_resource(dev, SYS_RES_MEMORY, rid, res);
+		return (ENXIO);
+	}
+
+	/* Check the SMCCC is at least v1.1 */
+	smccc_version = smccc_get_version();
+	if (SMCCC_VERSION_MAJOR(smccc_version) > 1 ||
+	    (SMCCC_VERSION_MAJOR(smccc_version) == 1 &&
+	     SMCCC_VERSION_MINOR(smccc_version) == 0)) {
+		device_set_desc(dev,
+		    "ARM PCI Firmware config space host controller");
+		return (BUS_PROBE_SPECIFIC);
+	}
+
+	return (EINVAL);
+}
+
+#define	SMCCC_PCI_VERSION						\
+    SMCCC_FUNC_ID(SMCCC_FAST_CALL, SMCCC_32BIT_CALL,			\
+    SMCCC_STD_SECURE_SERVICE_CALLS, 0x130)
+#define	SMCCC_PCI_FEATURES						\
+    SMCCC_FUNC_ID(SMCCC_FAST_CALL, SMCCC_32BIT_CALL,			\
+    SMCCC_STD_SECURE_SERVICE_CALLS, 0x131)
+#define	SMCCC_PCI_READ						\
+    SMCCC_FUNC_ID(SMCCC_FAST_CALL, SMCCC_32BIT_CALL,			\
+    SMCCC_STD_SECURE_SERVICE_CALLS, 0x132)
+#define	SMCCC_PCI_WRITE						\
+    SMCCC_FUNC_ID(SMCCC_FAST_CALL, SMCCC_32BIT_CALL,			\
+    SMCCC_STD_SECURE_SERVICE_CALLS, 0x133)
+#define	SMCCC_PCI_GET_SEG_INFO						\
+    SMCCC_FUNC_ID(SMCCC_FAST_CALL, SMCCC_32BIT_CALL,			\
+    SMCCC_STD_SECURE_SERVICE_CALLS, 0x134)
+
+CTASSERT(SMCCC_PCI_VERSION == 0x84000130);
+CTASSERT(SMCCC_PCI_FEATURES == 0x84000131);
+CTASSERT(SMCCC_PCI_READ == 0x84000132);
+CTASSERT(SMCCC_PCI_WRITE == 0x84000133);
+CTASSERT(SMCCC_PCI_GET_SEG_INFO == 0x84000134);
+
+#define	SMCCC_PCI_MAJOR(x)	(((x) >> 16) & 0x7fff)
+#define	SMCCC_PCI_MINOR(x)	((x) & 0xffff)
+
+#define	SMCCC_PCI_SEG_END(x)	(((x) >> 8) & 0xff)
+#define	SMCCC_PCI_SEG_START(x)	((x) & 0xff)
+
+static bool
+pci_host_acpi_smccc_has_feature(uint32_t pci_func_id)
+{
+	struct arm_smccc_res result;
+
+	if (psci_callfn(SMCCC_PCI_FEATURES, pci_func_id, 0, 0, 0, 0, 0, 0,
+	    &result) < 0) {
+		return (false);
+	}
+
+	return (true);
+}
+
+static int
+pci_host_acpi_smccc_attach(device_t dev)
+{
+	struct generic_pcie_acpi_softc *sc;
+	struct arm_smccc_res result;
+	int end, start;
+	int error;
+
+	sc = device_get_softc(dev);
+	sc->base.quirks |= PCIE_CUSTOM_CONFIG_SPACE_QUIRK;
+
+	MPASS(psci_callfn != NULL);
+
+	/* Check there is a version */
+	if (psci_callfn(SMCCC_PCI_VERSION, 0, 0, 0, 0, 0, 0, 0, &result) < 0) {
+		device_printf(dev,
+		    "Failed to read the SMCCC PCI version: %lx\n", result.a0);
+		return (ENXIO);
+	}
+
+	if (bootverbose) {
+		device_printf(dev, "Firmware v%d.%d\n",
+		    SMCCC_PCI_MAJOR((uint32_t)result.a0),
+		    SMCCC_PCI_MINOR((uint32_t)result.a0));
+	}
+
+	if (!pci_host_acpi_smccc_has_feature(SMCCC_PCI_READ) ||
+	    !pci_host_acpi_smccc_has_feature(SMCCC_PCI_WRITE)) {
+		device_printf(dev, "Missing read/write functions\n");
+		return (ENXIO);
+	}
+
+	error = pci_host_generic_acpi_init(dev);
+	if (error != 0)
+		return (error);
+
+	if (pci_host_acpi_smccc_has_feature(SMCCC_PCI_GET_SEG_INFO) &&
+	    psci_callfn(SMCCC_PCI_GET_SEG_INFO, sc->base.ecam, 0, 0, 0, 0, 0,
+	     0, &result) == SMCCC_RET_SUCCESS) {
+		start = SMCCC_PCI_SEG_START(result.a1);
+		end = SMCCC_PCI_SEG_END(result.a1);
+
+		sc->base.bus_start = MAX(sc->base.bus_start, start);
+		sc->base.bus_end = MIN(sc->base.bus_end, end);
+	}
+
+	device_add_child(dev, "pci", -1);
+	return (bus_generic_attach(dev));
+}
+
+static uint32_t
+pci_host_acpi_smccc_read_config(device_t dev, u_int bus, u_int slot,
+    u_int func, u_int reg, int bytes)
+{
+	struct generic_pcie_acpi_softc *sc;
+	struct arm_smccc_res result;
+	uint32_t addr;
+
+	sc = device_get_softc(dev);
+
+	if ((bus < sc->base.bus_start) || (bus > sc->base.bus_end))
+		return (~0U);
+	if ((slot > PCI_SLOTMAX) || (func > PCI_FUNCMAX) ||
+	    (reg > PCIE_REGMAX))
+		return (~0U);
+
+	addr = (sc->base.ecam << 16) | (bus << 8) | (slot << 3) | (func << 0);
+	if (psci_callfn(SMCCC_PCI_READ, addr, reg, bytes, 0, 0, 0, 0,
+	    &result) < 0) {
+		return (~0U);
+	}
+
+	return (result.a1);
+}
+
+static void
+pci_host_acpi_smccc_write_config(device_t dev, u_int bus, u_int slot,
+    u_int func, u_int reg, uint32_t val, int bytes)
+{
+	struct generic_pcie_acpi_softc *sc;
+	struct arm_smccc_res result;
+	uint32_t addr;
+
+	sc = device_get_softc(dev);
+
+	if ((bus < sc->base.bus_start) || (bus > sc->base.bus_end))
+		return;
+	if ((slot > PCI_SLOTMAX) || (func > PCI_FUNCMAX) ||
+	    (reg > PCIE_REGMAX))
+		return;
+
+	addr = (sc->base.ecam << 16) | (bus << 8) | (slot << 3) | (func << 0);
+	psci_callfn(SMCCC_PCI_WRITE, addr, reg, bytes, val, 0, 0, 0, &result);
+}
+
+static device_method_t generic_pcie_acpi_smccc_methods[] = {
+	DEVMETHOD(device_probe,		pci_host_acpi_smccc_probe),
+	DEVMETHOD(device_attach,	pci_host_acpi_smccc_attach),
+
+	/* pcib interface */
+	DEVMETHOD(pcib_read_config,	pci_host_acpi_smccc_read_config),
+	DEVMETHOD(pcib_write_config,	pci_host_acpi_smccc_write_config),
+
+	DEVMETHOD_END
+};
+
+DEFINE_CLASS_1(pcib, generic_pcie_acpi_smccc_driver,
+    generic_pcie_acpi_smccc_methods,
+    sizeof(struct generic_pcie_acpi_softc), generic_pcie_acpi_driver);
+
+DRIVER_MODULE(pcib_smccc, acpi, generic_pcie_acpi_smccc_driver, 0, 0);