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Date:      Tue, 1 Apr 2014 16:02:02 +0000 (UTC)
From:      Ryan Stone <rstone@FreeBSD.org>
To:        src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org
Subject:   svn commit: r264011 - head/sys/dev/pci
Message-ID:  <201404011602.s31G22QT056325@svn.freebsd.org>

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Author: rstone
Date: Tue Apr  1 16:02:02 2014
New Revision: 264011
URL: http://svnweb.freebsd.org/changeset/base/264011

Log:
  Add support for PCIe ARI
  
  PCIe Alternate RID Interpretation (ARI) is an optional feature that
  allows devices to have up to 256 different functions.  It is
  implemented by always setting the PCI slot number to 0 and
  re-purposing the 5 bits used to encode the slot number to instead
  contain the function number.  Combined with the original 3 bits
  allocated for the function number, this allows for 256 functions.
  
  This is enabled by default, but it's expected to be a no-op on currently
  supported hardware.  It's a prerequisite for supporting PCI SR-IOV, and
  I want the ARI support to go in early to help shake out any bugs in it.
  ARI can be disabled by setting the tunable hw.pci.enable_ari=0.
  
  Reviewed by:	kib
  MFC after:	2 months
  Sponsored by:	Sandvine Inc.

Modified:
  head/sys/dev/pci/pci.c
  head/sys/dev/pci/pci_pci.c
  head/sys/dev/pci/pcib_if.m
  head/sys/dev/pci/pcib_private.h
  head/sys/dev/pci/pcib_support.c
  head/sys/dev/pci/pcireg.h

Modified: head/sys/dev/pci/pci.c
==============================================================================
--- head/sys/dev/pci/pci.c	Tue Apr  1 15:56:31 2014	(r264010)
+++ head/sys/dev/pci/pci.c	Tue Apr  1 16:02:02 2014	(r264011)
@@ -354,6 +354,11 @@ SYSCTL_INT(_hw_pci, OID_AUTO, clear_buse
     "Ignore firmware-assigned bus numbers.");
 #endif
 
+static int pci_enable_ari = 1;
+TUNABLE_INT("hw.pci.enable_ari", &pci_enable_ari);
+SYSCTL_INT(_hw_pci, OID_AUTO, enable_ari, CTLFLAG_RDTUN, &pci_enable_ari,
+    0, "Enable support for PCIe Alternative RID Interpretation");
+
 static int
 pci_has_quirk(uint32_t devid, int quirk)
 {
@@ -3454,6 +3459,19 @@ pci_add_resources(device_t bus, device_t
 #endif
 }
 
+static struct pci_devinfo *
+pci_identify_function(device_t pcib, device_t dev, int domain, int busno,
+    int slot, int func, size_t dinfo_size)
+{
+	struct pci_devinfo *dinfo;
+
+	dinfo = pci_read_device(pcib, domain, busno, slot, func, dinfo_size);
+	if (dinfo != NULL)
+		pci_add_child(dev, dinfo);
+
+	return (dinfo);
+}
+
 void
 pci_add_children(device_t dev, int domain, int busno, size_t dinfo_size)
 {
@@ -3463,6 +3481,24 @@ pci_add_children(device_t dev, int domai
 	int maxslots;
 	int s, f, pcifunchigh;
 	uint8_t hdrtype;
+	int first_func;
+
+	/*
+	 * Try to detect a device at slot 0, function 0.  If it exists, try to
+	 * enable ARI.  We must enable ARI before detecting the rest of the
+	 * functions on this bus as ARI changes the set of slots and functions
+	 * that are legal on this bus.
+	 */
+	dinfo = pci_identify_function(pcib, dev, domain, busno, 0, 0,
+	    dinfo_size);
+	if (dinfo != NULL && pci_enable_ari)
+		PCIB_TRY_ENABLE_ARI(pcib, dinfo->cfg.dev);
+
+	/*
+	 * Start looking for new devices on slot 0 at function 1 because we
+	 * just identified the device at slot 0, function 0.
+	 */
+	first_func = 1;
 
 	KASSERT(dinfo_size >= sizeof(struct pci_devinfo),
 	    ("dinfo_size too small"));
@@ -3475,14 +3511,13 @@ pci_add_children(device_t dev, int domai
 		if ((hdrtype & PCIM_HDRTYPE) > PCI_MAXHDRTYPE)
 			continue;
 		if (hdrtype & PCIM_MFDEV)
-			pcifunchigh = PCI_FUNCMAX;
-		for (f = 0; f <= pcifunchigh; f++) {
-			dinfo = pci_read_device(pcib, domain, busno, s, f,
+			pcifunchigh = PCIB_MAXFUNCS(pcib);
+		for (f = first_func; f <= pcifunchigh; f++)
+			pci_identify_function(pcib, dev, domain, busno, s, f,
 			    dinfo_size);
-			if (dinfo != NULL) {
-				pci_add_child(dev, dinfo);
-			}
-		}
+
+		/* For slots after slot 0 we need to check for function 0. */
+		first_func = 0;
 	}
 #undef REG
 }

Modified: head/sys/dev/pci/pci_pci.c
==============================================================================
--- head/sys/dev/pci/pci_pci.c	Tue Apr  1 15:56:31 2014	(r264010)
+++ head/sys/dev/pci/pci_pci.c	Tue Apr  1 16:02:02 2014	(r264011)
@@ -56,6 +56,14 @@ static int		pcib_suspend(device_t dev);
 static int		pcib_resume(device_t dev);
 static int		pcib_power_for_sleep(device_t pcib, device_t dev,
 			    int *pstate);
+static uint16_t		pcib_ari_get_rid(device_t pcib, device_t dev);
+static uint32_t		pcib_read_config(device_t dev, u_int b, u_int s, 
+    u_int f, u_int reg, int width);
+static void		pcib_write_config(device_t dev, u_int b, u_int s,
+    u_int f, u_int reg, uint32_t val, int width);
+static int		pcib_ari_maxslots(device_t dev);
+static int		pcib_ari_maxfuncs(device_t dev);
+static int		pcib_try_enable_ari(device_t pcib, device_t dev);
 
 static device_method_t pcib_methods[] = {
     /* Device interface */
@@ -83,7 +91,8 @@ static device_method_t pcib_methods[] = 
     DEVMETHOD(bus_teardown_intr,	bus_generic_teardown_intr),
 
     /* pcib interface */
-    DEVMETHOD(pcib_maxslots,		pcib_maxslots),
+    DEVMETHOD(pcib_maxslots,		pcib_ari_maxslots),
+    DEVMETHOD(pcib_maxfuncs,		pcib_ari_maxfuncs),
     DEVMETHOD(pcib_read_config,		pcib_read_config),
     DEVMETHOD(pcib_write_config,	pcib_write_config),
     DEVMETHOD(pcib_route_interrupt,	pcib_route_interrupt),
@@ -93,7 +102,8 @@ static device_method_t pcib_methods[] = 
     DEVMETHOD(pcib_release_msix,	pcib_release_msix),
     DEVMETHOD(pcib_map_msi,		pcib_map_msi),
     DEVMETHOD(pcib_power_for_sleep,	pcib_power_for_sleep),
-    DEVMETHOD(pcib_get_rid,		pcib_get_rid),
+    DEVMETHOD(pcib_get_rid,		pcib_ari_get_rid),
+    DEVMETHOD(pcib_try_enable_ari,	pcib_try_enable_ari),
 
     DEVMETHOD_END
 };
@@ -1803,27 +1813,94 @@ pcib_alloc_resource(device_t dev, device
 #endif
 
 /*
+ * If ARI is enabled on this downstream port, translate the function number
+ * to the non-ARI slot/function.  The downstream port will convert it back in
+ * hardware.  If ARI is not enabled slot and func are not modified.
+ */
+static __inline void
+pcib_xlate_ari(device_t pcib, int bus, int *slot, int *func)
+{
+	struct pcib_softc *sc;
+	int ari_func;
+
+	sc = device_get_softc(pcib);
+	ari_func = *func;
+
+	if (sc->flags & PCIB_ENABLE_ARI) {
+		KASSERT(*slot == 0,
+		    ("Non-zero slot number with ARI enabled!"));
+		*slot = PCIE_ARI_SLOT(ari_func);
+		*func = PCIE_ARI_FUNC(ari_func);
+	}
+}
+
+
+static void
+pcib_enable_ari(struct pcib_softc *sc, uint32_t pcie_pos)
+{
+	uint32_t ctl2;
+
+	ctl2 = pci_read_config(sc->dev, pcie_pos + PCIER_DEVICE_CTL2, 4);
+	ctl2 |= PCIEM_CTL2_ARI;
+	pci_write_config(sc->dev, pcie_pos + PCIER_DEVICE_CTL2, ctl2, 4);
+
+	sc->flags |= PCIB_ENABLE_ARI;
+}
+
+/*
  * PCIB interface.
  */
 int
 pcib_maxslots(device_t dev)
 {
-    return(PCI_SLOTMAX);
+	return (PCI_SLOTMAX);
+}
+
+static int
+pcib_ari_maxslots(device_t dev)
+{
+	struct pcib_softc *sc;
+
+	sc = device_get_softc(dev);
+
+	if (sc->flags & PCIB_ENABLE_ARI)
+		return (PCIE_ARI_SLOTMAX);
+	else
+		return (PCI_SLOTMAX);
+}
+
+static int
+pcib_ari_maxfuncs(device_t dev)
+{
+	struct pcib_softc *sc;
+
+	sc = device_get_softc(dev);
+
+	if (sc->flags & PCIB_ENABLE_ARI)
+		return (PCIE_ARI_FUNCMAX);
+	else
+		return (PCI_FUNCMAX);
 }
 
 /*
  * Since we are a child of a PCI bus, its parent must support the pcib interface.
  */
-uint32_t
+static uint32_t
 pcib_read_config(device_t dev, u_int b, u_int s, u_int f, u_int reg, int width)
 {
-    return(PCIB_READ_CONFIG(device_get_parent(device_get_parent(dev)), b, s, f, reg, width));
+
+	pcib_xlate_ari(dev, b, &s, &f);
+	return(PCIB_READ_CONFIG(device_get_parent(device_get_parent(dev)), b, s,
+	    f, reg, width));
 }
 
-void
+static void
 pcib_write_config(device_t dev, u_int b, u_int s, u_int f, u_int reg, uint32_t val, int width)
 {
-    PCIB_WRITE_CONFIG(device_get_parent(device_get_parent(dev)), b, s, f, reg, val, width);
+
+	pcib_xlate_ari(dev, b, &s, &f);
+	PCIB_WRITE_CONFIG(device_get_parent(device_get_parent(dev)), b, s, f,
+	    reg, val, width);
 }
 
 /*
@@ -1936,3 +2013,82 @@ pcib_power_for_sleep(device_t pcib, devi
 	return (PCIB_POWER_FOR_SLEEP(bus, dev, pstate));
 }
 
+static uint16_t
+pcib_ari_get_rid(device_t pcib, device_t dev)
+{
+	struct pcib_softc *sc;
+	uint8_t bus, slot, func;
+
+	sc = device_get_softc(pcib);
+
+	if (sc->flags & PCIB_ENABLE_ARI) {
+		bus = pci_get_bus(dev);
+		func = pci_get_function(dev);
+
+		return (PCI_ARI_RID(bus, func));
+	} else {
+		bus = pci_get_bus(dev);
+		slot = pci_get_slot(dev);
+		func = pci_get_function(dev);
+
+		return (PCI_RID(bus, slot, func));
+	}
+}
+
+/*
+ * Check that the downstream port (pcib) and the endpoint device (dev) both
+ * support ARI.  If so, enable it and return 0, otherwise return an error.
+ */
+static int
+pcib_try_enable_ari(device_t pcib, device_t dev)
+{
+	struct pcib_softc *sc;
+	int error;
+	uint32_t cap2;
+	int ari_cap_off;
+	uint32_t ari_ver;
+	uint32_t pcie_pos;
+
+	sc = device_get_softc(pcib);
+
+	/*
+	 * ARI is controlled in a register in the PCIe capability structure.
+	 * If the downstream port does not have the PCIe capability structure
+	 * then it does not support ARI.
+	 */
+	error = pci_find_cap(pcib, PCIY_EXPRESS, &pcie_pos);
+	if (error != 0)
+		return (ENODEV);
+
+	/* Check that the PCIe port advertises ARI support. */
+	cap2 = pci_read_config(pcib, pcie_pos + PCIER_DEVICE_CAP2, 4);
+	if (!(cap2 & PCIEM_CAP2_ARI))
+		return (ENODEV);
+
+	/*
+	 * Check that the endpoint device advertises ARI support via the ARI
+	 * extended capability structure.
+	 */
+	error = pci_find_extcap(dev, PCIZ_ARI, &ari_cap_off);
+	if (error != 0)
+		return (ENODEV);
+
+	/*
+	 * Finally, check that the endpoint device supports the same version
+	 * of ARI that we do.
+	 */
+	ari_ver = pci_read_config(dev, ari_cap_off, 4);
+	if (PCI_EXTCAP_VER(ari_ver) != PCIB_SUPPORTED_ARI_VER) {
+		if (bootverbose)
+			device_printf(pcib,
+			    "Unsupported version of ARI (%d) detected\n",
+			    PCI_EXTCAP_VER(ari_ver));
+
+		return (ENXIO);
+	}
+
+	pcib_enable_ari(sc, pcie_pos);
+
+	return (0);
+}
+

Modified: head/sys/dev/pci/pcib_if.m
==============================================================================
--- head/sys/dev/pci/pcib_if.m	Tue Apr  1 15:56:31 2014	(r264010)
+++ head/sys/dev/pci/pcib_if.m	Tue Apr  1 16:02:02 2014	(r264011)
@@ -27,7 +27,9 @@
 #
 
 #include <sys/bus.h>
+#include <sys/rman.h>
 #include <dev/pci/pcivar.h>
+#include <dev/pci/pcib_private.h>
 
 INTERFACE pcib;
 
@@ -47,6 +49,14 @@ METHOD int maxslots {
 };
 
 #
+#
+# Return the number of functions on the attached PCI bus.
+#
+METHOD int maxfuncs {
+	device_t	dev;
+} DEFAULT pcib_maxfuncs;
+
+#
 # Read configuration space on the PCI bus. The bus, slot and func
 # arguments determine the device which is being read and the reg
 # argument is a byte offset into configuration space for that
@@ -161,5 +171,14 @@ METHOD int power_for_sleep {
 METHOD uint16_t get_rid {
 	device_t pcib;
 	device_t dev;
+} DEFAULT pcib_get_rid;
+
+#
+# Enable Alternative RID Interpretation if both the downstream port (pcib)
+# and the endpoint device (dev) both support it.
+#
+METHOD int try_enable_ari {
+	device_t	pcib;
+	device_t	dev;
 };
 

Modified: head/sys/dev/pci/pcib_private.h
==============================================================================
--- head/sys/dev/pci/pcib_private.h	Tue Apr  1 15:56:31 2014	(r264010)
+++ head/sys/dev/pci/pcib_private.h	Tue Apr  1 16:02:02 2014	(r264011)
@@ -105,6 +105,7 @@ struct pcib_softc 
 #define	PCIB_SUBTRACTIVE	0x1
 #define	PCIB_DISABLE_MSI	0x2
 #define	PCIB_DISABLE_MSIX	0x4
+#define	PCIB_ENABLE_ARI		0x8
     uint16_t	command;	/* command register */
     u_int	domain;		/* domain number */
     u_int	pribus;		/* primary bus number */
@@ -126,6 +127,8 @@ struct pcib_softc 
     uint8_t	seclat;		/* secondary bus latency timer */
 };
 
+#define	PCIB_SUPPORTED_ARI_VER	1
+
 typedef uint32_t pci_read_config_fn(int b, int s, int f, int reg, int width);
 
 int		host_pcib_get_busno(pci_read_config_fn read_config, int bus,
@@ -159,8 +162,7 @@ int		pcib_release_resource(device_t dev,
     struct resource *r);
 #endif
 int		pcib_maxslots(device_t dev);
-uint32_t	pcib_read_config(device_t dev, u_int b, u_int s, u_int f, u_int reg, int width);
-void		pcib_write_config(device_t dev, u_int b, u_int s, u_int f, u_int reg, uint32_t val, int width);
+int		pcib_maxfuncs(device_t dev);
 int		pcib_route_interrupt(device_t pcib, device_t dev, int pin);
 int		pcib_alloc_msi(device_t pcib, device_t dev, int count, int maxcount, int *irqs);
 int		pcib_release_msi(device_t pcib, device_t dev, int count, int *irqs);
@@ -169,5 +171,4 @@ int		pcib_release_msix(device_t pcib, de
 int		pcib_map_msi(device_t pcib, device_t dev, int irq, uint64_t *addr, uint32_t *data);
 uint16_t	pcib_get_rid(device_t pcib, device_t dev);
 
-
 #endif

Modified: head/sys/dev/pci/pcib_support.c
==============================================================================
--- head/sys/dev/pci/pcib_support.c	Tue Apr  1 15:56:31 2014	(r264010)
+++ head/sys/dev/pci/pcib_support.c	Tue Apr  1 16:02:02 2014	(r264011)
@@ -48,6 +48,12 @@ __FBSDID("$FreeBSD$");
 
 #include "pcib_if.h"
 
+int
+pcib_maxfuncs(device_t dev)
+{
+	return (PCI_FUNCMAX);
+}
+
 uint16_t
 pcib_get_rid(device_t pcib, device_t dev)
 {

Modified: head/sys/dev/pci/pcireg.h
==============================================================================
--- head/sys/dev/pci/pcireg.h	Tue Apr  1 15:56:31 2014	(r264010)
+++ head/sys/dev/pci/pcireg.h	Tue Apr  1 16:02:02 2014	(r264011)
@@ -48,6 +48,9 @@
 #define	PCIE_REGMAX	4095	/* highest supported config register addr. */
 #define	PCI_MAXHDRTYPE	2
 
+#define	PCIE_ARI_SLOTMAX 0
+#define	PCIE_ARI_FUNCMAX 255
+
 #define	PCI_RID_BUS_SHIFT	8
 #define	PCI_RID_SLOT_SHIFT	3
 #define	PCI_RID_FUNC_SHIFT	0
@@ -65,6 +68,9 @@
 #define PCI_RID2SLOT(rid) (((rid) >> PCI_RID_SLOT_SHIFT) & PCI_SLOTMAX)
 #define PCI_RID2FUNC(rid) (((rid) >> PCI_RID_FUNC_SHIFT) & PCI_FUNCMAX)
 
+#define PCIE_ARI_SLOT(func) (((func) >> PCI_RID_SLOT_SHIFT) & PCI_SLOTMAX)
+#define PCIE_ARI_FUNC(func) (((func) >> PCI_RID_FUNC_SHIFT) & PCI_FUNCMAX)
+
 /* PCI config header registers for all devices */
 
 #define	PCIR_DEVVENDOR	0x00
@@ -791,6 +797,7 @@
 #define	PCIEM_ROOT_STA_PME_STATUS	0x00010000
 #define	PCIEM_ROOT_STA_PME_PEND		0x00020000
 #define	PCIER_DEVICE_CAP2	0x24
+#define	PCIEM_CAP2_ARI		0x20
 #define	PCIER_DEVICE_CTL2	0x28
 #define	PCIEM_CTL2_COMP_TIMEOUT_VAL	0x000f
 #define	PCIEM_CTL2_COMP_TIMEOUT_DIS	0x0010
@@ -911,3 +918,4 @@
 /* Serial Number definitions */
 #define	PCIR_SERIAL_LOW		0x04
 #define	PCIR_SERIAL_HIGH	0x08
+



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