[PATCH v3 00/3] MIPS: SGI-IP27 rework part2

[PATCH v3 00/3] MIPS: SGI-IP27 rework part2

[Thomas Bogendoerfer]

SGI IP27 (Origin/Onyx2) and SGI IP30 (Octane) have a similair
architecture and share some hardware (ioc3/bridge). To share
the software parts this patchset reworks SGI IP27 interrupt
and pci bridge code. By using features Linux gained during the
many years since SGI IP27 code was integrated this even results
in code reduction and IMHO cleaner code.

Tests have been done on a two module O200 (4 CPUs) and an
Origin 2000 (8 CPUs).

My next step in integrating SGI IP30 support is splitting ioc3eth
into a MFD and subdevice drivers, which will be submitted soon.

Changes in v3:

- dropped patches accepted by Paul
- moved IP27 specific __phys_to_dma/__dma_to_phys into its own file
- moved pcibios_to_node into IP27 specific file
- moved PCI bus address resources setup out of pci-xtalk code into
  IP27 specific code
- dropped bit from hub_irq_data and use hwirq from irq_data
- introduced intr_addr for setting up bridge interrupts (IP30 preperation)

Changes in v2:

- replaced HUB_L/HUB_S by __raw_readq/__raw_writeq
- removed union bridge_ate
- replaced remaing fields in slice_data by per_cpu data
- use generic_handle_irq instead of do_IRQ
- use hierarchy irq domain for stacking bridge and hub interrupt
- moved __dma_to_phys/__phy_to_dma to mach-ip27/dma-direct.h
- use dev_to_node() for pcibus_to_node() implementation

Thomas Bogendoerfer (3):
  MIPS: SGI-IP27: move IP27 specific code out of pci-ip27.c into new
    file
  MIPS: SGI-IP27: use generic PCI driver
  MIPS: SGI-IP27: abstract chipset irq from bridge

 arch/mips/Kconfig                          |   3 +
 arch/mips/include/asm/mach-ip27/topology.h |  11 +-
 arch/mips/include/asm/pci/bridge.h         |  14 +-
 arch/mips/include/asm/sn/irq_alloc.h       |  11 +
 arch/mips/include/asm/xtalk/xtalk.h        |   9 -
 arch/mips/pci/Makefile                     |   1 -
 arch/mips/pci/ops-bridge.c                 | 302 --------------
 arch/mips/pci/pci-ip27.c                   | 214 ----------
 arch/mips/sgi-ip27/Makefile                |   4 +-
 arch/mips/sgi-ip27/ip27-init.c             |   2 +
 arch/mips/sgi-ip27/ip27-irq.c              | 191 ++++-----
 arch/mips/sgi-ip27/ip27-pci.c              |  30 ++
 arch/mips/sgi-ip27/ip27-xtalk.c            |  61 ++-
 drivers/pci/controller/Kconfig             |   3 +
 drivers/pci/controller/Makefile            |   1 +
 drivers/pci/controller/pci-xtalk-bridge.c  | 610 +++++++++++++++++++++++++++++
 include/linux/platform_data/xtalk-bridge.h |  22 ++
 17 files changed, 822 insertions(+), 667 deletions(-)
 create mode 100644 arch/mips/include/asm/sn/irq_alloc.h
 delete mode 100644 arch/mips/pci/ops-bridge.c
 delete mode 100644 arch/mips/pci/pci-ip27.c
 create mode 100644 arch/mips/sgi-ip27/ip27-pci.c
 create mode 100644 drivers/pci/controller/pci-xtalk-bridge.c
 create mode 100644 include/linux/platform_data/xtalk-bridge.h

-- 
2.13.7

[PATCH v3 1/3] MIPS: SGI-IP27: move IP27 specific code out of pci-ip27.c into new file

[Thomas Bogendoerfer]

Code in pci-ip27.c will be moved to drivers/pci/controller therefore
platform specific needs to be extracted and put to the right place.

Signed-off-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 arch/mips/pci/pci-ip27.c      | 23 -----------------------
 arch/mips/sgi-ip27/Makefile   |  4 ++--
 arch/mips/sgi-ip27/ip27-pci.c | 30 ++++++++++++++++++++++++++++++
 3 files changed, 32 insertions(+), 25 deletions(-)
 create mode 100644 arch/mips/sgi-ip27/ip27-pci.c

diff --git a/arch/mips/pci/pci-ip27.c b/arch/mips/pci/pci-ip27.c
index 3c177b4d0609..0b0f9c4eaf04 100644
--- a/arch/mips/pci/pci-ip27.c
+++ b/arch/mips/pci/pci-ip27.c
@@ -164,19 +164,6 @@ int pcibios_plat_dev_init(struct pci_dev *dev)
 	return 0;
 }
 
-dma_addr_t __phys_to_dma(struct device *dev, phys_addr_t paddr)
-{
-	struct pci_dev *pdev = to_pci_dev(dev);
-	struct bridge_controller *bc = BRIDGE_CONTROLLER(pdev->bus);
-
-	return bc->baddr + paddr;
-}
-
-phys_addr_t __dma_to_phys(struct device *dev, dma_addr_t dma_addr)
-{
-	return dma_addr & ~(0xffUL << 56);
-}
-
 /*
  * Device might live on a subordinate PCI bus.	XXX Walk up the chain of buses
  * to find the slot number in sense of the bridge device register.
@@ -200,15 +187,5 @@ static void pci_fixup_ioc3(struct pci_dev *d)
 	pci_disable_swapping(d);
 }
 
-#ifdef CONFIG_NUMA
-int pcibus_to_node(struct pci_bus *bus)
-{
-	struct bridge_controller *bc = BRIDGE_CONTROLLER(bus);
-
-	return bc->nasid;
-}
-EXPORT_SYMBOL(pcibus_to_node);
-#endif /* CONFIG_NUMA */
-
 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_SGI, PCI_DEVICE_ID_SGI_IOC3,
 	pci_fixup_ioc3);
diff --git a/arch/mips/sgi-ip27/Makefile b/arch/mips/sgi-ip27/Makefile
index 27c14ede191e..f9694f2b20b1 100644
--- a/arch/mips/sgi-ip27/Makefile
+++ b/arch/mips/sgi-ip27/Makefile
@@ -3,8 +3,8 @@
 # Makefile for the IP27 specific kernel interface routines under Linux.
 #
 
-obj-y	:= ip27-berr.o ip27-irq.o ip27-init.o ip27-klconfig.o \
-	   ip27-klnuma.o ip27-memory.o ip27-nmi.o ip27-reset.o ip27-timer.o \
+obj-y	:= ip27-berr.o ip27-irq.o ip27-init.o ip27-klconfig.o ip27-klnuma.o \
+	   ip27-memory.o ip27-nmi.o ip27-pci.o ip27-reset.o ip27-timer.o \
 	   ip27-hubio.o ip27-xtalk.o
 
 obj-$(CONFIG_EARLY_PRINTK)	+= ip27-console.o
diff --git a/arch/mips/sgi-ip27/ip27-pci.c b/arch/mips/sgi-ip27/ip27-pci.c
new file mode 100644
index 000000000000..d3efa5fbe8a3
--- /dev/null
+++ b/arch/mips/sgi-ip27/ip27-pci.c
@@ -0,0 +1,30 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * ip27-pci.c: misc PCI related helper code for IP27 architecture
+ */
+
+#include <asm/pci/bridge.h>
+
+dma_addr_t __phys_to_dma(struct device *dev, phys_addr_t paddr)
+{
+	struct pci_dev *pdev = to_pci_dev(dev);
+	struct bridge_controller *bc = BRIDGE_CONTROLLER(pdev->bus);
+
+	return bc->baddr + paddr;
+}
+
+phys_addr_t __dma_to_phys(struct device *dev, dma_addr_t dma_addr)
+{
+	return dma_addr & ~(0xffUL << 56);
+}
+
+#ifdef CONFIG_NUMA
+int pcibus_to_node(struct pci_bus *bus)
+{
+	struct bridge_controller *bc = BRIDGE_CONTROLLER(bus);
+
+	return bc->nasid;
+}
+EXPORT_SYMBOL(pcibus_to_node);
+#endif /* CONFIG_NUMA */
+
-- 
2.13.7

[PATCH v3 2/3] MIPS: SGI-IP27: use generic PCI driver

[Thomas Bogendoerfer]

Converted bridge code to a platform driver using the PCI generic driver
framework and use adding platform devices during xtalk scan. This allows
easier sharing bridge driver for other SGI platforms like IP30 (Octane) and
IP35 (Origin 3k, Fuel, Tezro).

Signed-off-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 arch/mips/Kconfig                          |   2 +
 arch/mips/include/asm/mach-ip27/topology.h |  11 +-
 arch/mips/include/asm/pci/bridge.h         |  11 +-
 arch/mips/include/asm/xtalk/xtalk.h        |   9 -
 arch/mips/pci/Makefile                     |   1 -
 arch/mips/pci/ops-bridge.c                 | 302 -------------------
 arch/mips/pci/pci-ip27.c                   | 191 ------------
 arch/mips/sgi-ip27/ip27-init.c             |   2 +
 arch/mips/sgi-ip27/ip27-xtalk.c            |  61 +++-
 drivers/pci/controller/Kconfig             |   3 +
 drivers/pci/controller/Makefile            |   1 +
 drivers/pci/controller/pci-xtalk-bridge.c  | 452 +++++++++++++++++++++++++++++
 include/linux/platform_data/xtalk-bridge.h |  22 ++
 13 files changed, 535 insertions(+), 533 deletions(-)
 delete mode 100644 arch/mips/pci/ops-bridge.c
 delete mode 100644 arch/mips/pci/pci-ip27.c
 create mode 100644 drivers/pci/controller/pci-xtalk-bridge.c
 create mode 100644 include/linux/platform_data/xtalk-bridge.h

diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 4a5f5b0ee9a9..3f9b42580fd4 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -677,6 +677,8 @@ config SGI_IP27
 	select HAVE_PCI
 	select IRQ_MIPS_CPU
 	select NR_CPUS_DEFAULT_64
+	select PCI_DRIVERS_GENERIC
+	select PCI_XTALK_BRIDGE
 	select SYS_HAS_CPU_R10000
 	select SYS_SUPPORTS_64BIT_KERNEL
 	select SYS_SUPPORTS_BIG_ENDIAN
diff --git a/arch/mips/include/asm/mach-ip27/topology.h b/arch/mips/include/asm/mach-ip27/topology.h
index 42ea1313626c..965f0793a5f9 100644
--- a/arch/mips/include/asm/mach-ip27/topology.h
+++ b/arch/mips/include/asm/mach-ip27/topology.h
@@ -7,18 +7,9 @@
 #include <asm/mmzone.h>
 
 struct cpuinfo_ip27 {
-//	cpuid_t		p_cpuid;	/* PROM assigned cpuid */
 	cnodeid_t	p_nodeid;	/* my node ID in compact-id-space */
 	nasid_t		p_nasid;	/* my node ID in numa-as-id-space */
 	unsigned char	p_slice;	/* Physical position on node board */
-#if 0
-	unsigned long		loops_per_sec;
-	unsigned long		ipi_count;
-	unsigned long		irq_attempt[NR_IRQS];
-	unsigned long		smp_local_irq_count;
-	unsigned long		prof_multiplier;
-	unsigned long		prof_counter;
-#endif
 };
 
 extern struct cpuinfo_ip27 sn_cpu_info[NR_CPUS];
@@ -30,7 +21,7 @@ extern struct cpuinfo_ip27 sn_cpu_info[NR_CPUS];
 struct pci_bus;
 extern int pcibus_to_node(struct pci_bus *);
 
-#define cpumask_of_pcibus(bus)	(cpu_online_mask)
+#define cpumask_of_pcibus(bus)	(cpumask_of_node(pcibus_to_node(bus)))
 
 extern unsigned char __node_distances[MAX_COMPACT_NODES][MAX_COMPACT_NODES];
 
diff --git a/arch/mips/include/asm/pci/bridge.h b/arch/mips/include/asm/pci/bridge.h
index 23574c27eb40..d42b27c97c23 100644
--- a/arch/mips/include/asm/pci/bridge.h
+++ b/arch/mips/include/asm/pci/bridge.h
@@ -801,15 +801,12 @@ struct bridge_err_cmdword {
 #define PCI64_ATTR_RMF_SHFT	48
 
 struct bridge_controller {
-	struct pci_controller	pc;
-	struct resource		mem;
-	struct resource		io;
 	struct resource		busn;
 	struct bridge_regs	*base;
-	nasid_t			nasid;
-	unsigned int		widget_id;
-	u64			baddr;
+	unsigned long		baddr;
+	unsigned long		intr_addr;
 	unsigned int		pci_int[8];
+	nasid_t			nasid;
 };
 
 #define BRIDGE_CONTROLLER(bus) \
@@ -824,6 +821,4 @@ struct bridge_controller {
 
 extern int request_bridge_irq(struct bridge_controller *bc, int pin);
 
-extern struct pci_ops bridge_pci_ops;
-
 #endif /* _ASM_PCI_BRIDGE_H */
diff --git a/arch/mips/include/asm/xtalk/xtalk.h b/arch/mips/include/asm/xtalk/xtalk.h
index 26d2ed1fa917..680e7efebbaf 100644
--- a/arch/mips/include/asm/xtalk/xtalk.h
+++ b/arch/mips/include/asm/xtalk/xtalk.h
@@ -47,15 +47,6 @@ typedef struct xtalk_piomap_s *xtalk_piomap_t;
 #define XIO_PORT(x)	((xwidgetnum_t)(((x)&XIO_PORT_BITS) >> XIO_PORT_SHIFT))
 #define XIO_PACK(p, o)	((((uint64_t)(p))<<XIO_PORT_SHIFT) | ((o)&XIO_ADDR_BITS))
 
-#ifdef CONFIG_PCI
-extern int bridge_probe(nasid_t nasid, int widget, int masterwid);
-#else
-static inline int bridge_probe(nasid_t nasid, int widget, int masterwid)
-{
-	return 0;
-}
-#endif
-
 #endif /* !__ASSEMBLY__ */
 
 #endif /* _ASM_XTALK_XTALK_H */
diff --git a/arch/mips/pci/Makefile b/arch/mips/pci/Makefile
index c4f976593061..226a2806116d 100644
--- a/arch/mips/pci/Makefile
+++ b/arch/mips/pci/Makefile
@@ -39,7 +39,6 @@ obj-$(CONFIG_MIPS_MALTA)	+= fixup-malta.o pci-malta.o
 obj-$(CONFIG_PMC_MSP7120_GW)	+= fixup-pmcmsp.o ops-pmcmsp.o
 obj-$(CONFIG_PMC_MSP7120_EVAL)	+= fixup-pmcmsp.o ops-pmcmsp.o
 obj-$(CONFIG_PMC_MSP7120_FPGA)	+= fixup-pmcmsp.o ops-pmcmsp.o
-obj-$(CONFIG_SGI_IP27)		+= ops-bridge.o pci-ip27.o
 obj-$(CONFIG_SGI_IP32)		+= fixup-ip32.o ops-mace.o pci-ip32.o
 obj-$(CONFIG_SIBYTE_SB1250)	+= fixup-sb1250.o pci-sb1250.o
 obj-$(CONFIG_SIBYTE_BCM112X)	+= fixup-sb1250.o pci-sb1250.o
diff --git a/arch/mips/pci/ops-bridge.c b/arch/mips/pci/ops-bridge.c
deleted file mode 100644
index df95b0da08f2..000000000000
--- a/arch/mips/pci/ops-bridge.c
+++ /dev/null
@@ -1,302 +0,0 @@
-/*
- * 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) 1999, 2000, 04, 06 Ralf Baechle (ralf@linux-mips.org)
- * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
- */
-#include <linux/pci.h>
-#include <asm/paccess.h>
-#include <asm/pci/bridge.h>
-#include <asm/sn/arch.h>
-#include <asm/sn/intr.h>
-#include <asm/sn/sn0/hub.h>
-
-/*
- * Most of the IOC3 PCI config register aren't present
- * we emulate what is needed for a normal PCI enumeration
- */
-static u32 emulate_ioc3_cfg(int where, int size)
-{
-	if (size == 1 && where == 0x3d)
-		return 0x01;
-	else if (size == 2 && where == 0x3c)
-		return 0x0100;
-	else if (size == 4 && where == 0x3c)
-		return 0x00000100;
-
-	return 0;
-}
-
-/*
- * The Bridge ASIC supports both type 0 and type 1 access.  Type 1 is
- * not really documented, so right now I can't write code which uses it.
- * Therefore we use type 0 accesses for now even though they won't work
- * correctly for PCI-to-PCI bridges.
- *
- * The function is complicated by the ultimate brokenness of the IOC3 chip
- * which is used in SGI systems.  The IOC3 can only handle 32-bit PCI
- * accesses and does only decode parts of it's address space.
- */
-
-static int pci_conf0_read_config(struct pci_bus *bus, unsigned int devfn,
-				 int where, int size, u32 * value)
-{
-	struct bridge_controller *bc = BRIDGE_CONTROLLER(bus);
-	struct bridge_regs *bridge = bc->base;
-	int slot = PCI_SLOT(devfn);
-	int fn = PCI_FUNC(devfn);
-	volatile void *addr;
-	u32 cf, shift, mask;
-	int res;
-
-	addr = &bridge->b_type0_cfg_dev[slot].f[fn].c[PCI_VENDOR_ID];
-	if (get_dbe(cf, (u32 *) addr))
-		return PCIBIOS_DEVICE_NOT_FOUND;
-
-	/*
-	 * IOC3 is broken beyond belief ...  Don't even give the
-	 * generic PCI code a chance to look at it for real ...
-	 */
-	if (cf == (PCI_VENDOR_ID_SGI | (PCI_DEVICE_ID_SGI_IOC3 << 16)))
-		goto is_ioc3;
-
-	addr = &bridge->b_type0_cfg_dev[slot].f[fn].c[where ^ (4 - size)];
-
-	if (size == 1)
-		res = get_dbe(*value, (u8 *) addr);
-	else if (size == 2)
-		res = get_dbe(*value, (u16 *) addr);
-	else
-		res = get_dbe(*value, (u32 *) addr);
-
-	return res ? PCIBIOS_DEVICE_NOT_FOUND : PCIBIOS_SUCCESSFUL;
-
-is_ioc3:
-
-	/*
-	 * IOC3 special handling
-	 */
-	if ((where >= 0x14 && where < 0x40) || (where >= 0x48)) {
-		*value = emulate_ioc3_cfg(where, size);
-		return PCIBIOS_SUCCESSFUL;
-	}
-
-	addr = &bridge->b_type0_cfg_dev[slot].f[fn].l[where >> 2];
-
-	if (get_dbe(cf, (u32 *) addr))
-		return PCIBIOS_DEVICE_NOT_FOUND;
-
-	shift = ((where & 3) << 3);
-	mask = (0xffffffffU >> ((4 - size) << 3));
-	*value = (cf >> shift) & mask;
-
-	return PCIBIOS_SUCCESSFUL;
-}
-
-static int pci_conf1_read_config(struct pci_bus *bus, unsigned int devfn,
-				 int where, int size, u32 * value)
-{
-	struct bridge_controller *bc = BRIDGE_CONTROLLER(bus);
-	struct bridge_regs *bridge = bc->base;
-	int busno = bus->number;
-	int slot = PCI_SLOT(devfn);
-	int fn = PCI_FUNC(devfn);
-	volatile void *addr;
-	u32 cf, shift, mask;
-	int res;
-
-	bridge_write(bc, b_pci_cfg, (busno << 16) | (slot << 11));
-	addr = &bridge->b_type1_cfg.c[(fn << 8) | PCI_VENDOR_ID];
-	if (get_dbe(cf, (u32 *) addr))
-		return PCIBIOS_DEVICE_NOT_FOUND;
-
-	/*
-	 * IOC3 is broken beyond belief ...  Don't even give the
-	 * generic PCI code a chance to look at it for real ...
-	 */
-	if (cf == (PCI_VENDOR_ID_SGI | (PCI_DEVICE_ID_SGI_IOC3 << 16)))
-		goto is_ioc3;
-
-	bridge_write(bc, b_pci_cfg, (busno << 16) | (slot << 11));
-	addr = &bridge->b_type1_cfg.c[(fn << 8) | (where ^ (4 - size))];
-
-	if (size == 1)
-		res = get_dbe(*value, (u8 *) addr);
-	else if (size == 2)
-		res = get_dbe(*value, (u16 *) addr);
-	else
-		res = get_dbe(*value, (u32 *) addr);
-
-	return res ? PCIBIOS_DEVICE_NOT_FOUND : PCIBIOS_SUCCESSFUL;
-
-is_ioc3:
-
-	/*
-	 * IOC3 special handling
-	 */
-	if ((where >= 0x14 && where < 0x40) || (where >= 0x48)) {
-		*value = emulate_ioc3_cfg(where, size);
-		return PCIBIOS_SUCCESSFUL;
-	}
-
-	bridge_write(bc, b_pci_cfg, (busno << 16) | (slot << 11));
-	addr = &bridge->b_type1_cfg.c[(fn << 8) | where];
-
-	if (get_dbe(cf, (u32 *) addr))
-		return PCIBIOS_DEVICE_NOT_FOUND;
-
-	shift = ((where & 3) << 3);
-	mask = (0xffffffffU >> ((4 - size) << 3));
-	*value = (cf >> shift) & mask;
-
-	return PCIBIOS_SUCCESSFUL;
-}
-
-static int pci_read_config(struct pci_bus *bus, unsigned int devfn,
-			   int where, int size, u32 * value)
-{
-	if (!pci_is_root_bus(bus))
-		return pci_conf1_read_config(bus, devfn, where, size, value);
-
-	return pci_conf0_read_config(bus, devfn, where, size, value);
-}
-
-static int pci_conf0_write_config(struct pci_bus *bus, unsigned int devfn,
-				  int where, int size, u32 value)
-{
-	struct bridge_controller *bc = BRIDGE_CONTROLLER(bus);
-	struct bridge_regs *bridge = bc->base;
-	int slot = PCI_SLOT(devfn);
-	int fn = PCI_FUNC(devfn);
-	volatile void *addr;
-	u32 cf, shift, mask, smask;
-	int res;
-
-	addr = &bridge->b_type0_cfg_dev[slot].f[fn].c[PCI_VENDOR_ID];
-	if (get_dbe(cf, (u32 *) addr))
-		return PCIBIOS_DEVICE_NOT_FOUND;
-
-	/*
-	 * IOC3 is broken beyond belief ...  Don't even give the
-	 * generic PCI code a chance to look at it for real ...
-	 */
-	if (cf == (PCI_VENDOR_ID_SGI | (PCI_DEVICE_ID_SGI_IOC3 << 16)))
-		goto is_ioc3;
-
-	addr = &bridge->b_type0_cfg_dev[slot].f[fn].c[where ^ (4 - size)];
-
-	if (size == 1) {
-		res = put_dbe(value, (u8 *) addr);
-	} else if (size == 2) {
-		res = put_dbe(value, (u16 *) addr);
-	} else {
-		res = put_dbe(value, (u32 *) addr);
-	}
-
-	if (res)
-		return PCIBIOS_DEVICE_NOT_FOUND;
-
-	return PCIBIOS_SUCCESSFUL;
-
-is_ioc3:
-
-	/*
-	 * IOC3 special handling
-	 */
-	if ((where >= 0x14 && where < 0x40) || (where >= 0x48))
-		return PCIBIOS_SUCCESSFUL;
-
-	addr = &bridge->b_type0_cfg_dev[slot].f[fn].l[where >> 2];
-
-	if (get_dbe(cf, (u32 *) addr))
-		return PCIBIOS_DEVICE_NOT_FOUND;
-
-	shift = ((where & 3) << 3);
-	mask = (0xffffffffU >> ((4 - size) << 3));
-	smask = mask << shift;
-
-	cf = (cf & ~smask) | ((value & mask) << shift);
-	if (put_dbe(cf, (u32 *) addr))
-		return PCIBIOS_DEVICE_NOT_FOUND;
-
-	return PCIBIOS_SUCCESSFUL;
-}
-
-static int pci_conf1_write_config(struct pci_bus *bus, unsigned int devfn,
-				  int where, int size, u32 value)
-{
-	struct bridge_controller *bc = BRIDGE_CONTROLLER(bus);
-	struct bridge_regs *bridge = bc->base;
-	int slot = PCI_SLOT(devfn);
-	int fn = PCI_FUNC(devfn);
-	int busno = bus->number;
-	volatile void *addr;
-	u32 cf, shift, mask, smask;
-	int res;
-
-	bridge_write(bc, b_pci_cfg, (busno << 16) | (slot << 11));
-	addr = &bridge->b_type1_cfg.c[(fn << 8) | PCI_VENDOR_ID];
-	if (get_dbe(cf, (u32 *) addr))
-		return PCIBIOS_DEVICE_NOT_FOUND;
-
-	/*
-	 * IOC3 is broken beyond belief ...  Don't even give the
-	 * generic PCI code a chance to look at it for real ...
-	 */
-	if (cf == (PCI_VENDOR_ID_SGI | (PCI_DEVICE_ID_SGI_IOC3 << 16)))
-		goto is_ioc3;
-
-	addr = &bridge->b_type1_cfg.c[(fn << 8) | (where ^ (4 - size))];
-
-	if (size == 1) {
-		res = put_dbe(value, (u8 *) addr);
-	} else if (size == 2) {
-		res = put_dbe(value, (u16 *) addr);
-	} else {
-		res = put_dbe(value, (u32 *) addr);
-	}
-
-	if (res)
-		return PCIBIOS_DEVICE_NOT_FOUND;
-
-	return PCIBIOS_SUCCESSFUL;
-
-is_ioc3:
-
-	/*
-	 * IOC3 special handling
-	 */
-	if ((where >= 0x14 && where < 0x40) || (where >= 0x48))
-		return PCIBIOS_SUCCESSFUL;
-
-	addr = &bridge->b_type0_cfg_dev[slot].f[fn].l[where >> 2];
-
-	if (get_dbe(cf, (u32 *) addr))
-		return PCIBIOS_DEVICE_NOT_FOUND;
-
-	shift = ((where & 3) << 3);
-	mask = (0xffffffffU >> ((4 - size) << 3));
-	smask = mask << shift;
-
-	cf = (cf & ~smask) | ((value & mask) << shift);
-	if (put_dbe(cf, (u32 *) addr))
-		return PCIBIOS_DEVICE_NOT_FOUND;
-
-	return PCIBIOS_SUCCESSFUL;
-}
-
-static int pci_write_config(struct pci_bus *bus, unsigned int devfn,
-	int where, int size, u32 value)
-{
-	if (!pci_is_root_bus(bus))
-		return pci_conf1_write_config(bus, devfn, where, size, value);
-
-	return pci_conf0_write_config(bus, devfn, where, size, value);
-}
-
-struct pci_ops bridge_pci_ops = {
-	.read	= pci_read_config,
-	.write	= pci_write_config,
-};
diff --git a/arch/mips/pci/pci-ip27.c b/arch/mips/pci/pci-ip27.c
deleted file mode 100644
index 0b0f9c4eaf04..000000000000
--- a/arch/mips/pci/pci-ip27.c
+++ /dev/null
@@ -1,191 +0,0 @@
-/*
- * 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) 2003 Christoph Hellwig (hch@lst.de)
- * Copyright (C) 1999, 2000, 04 Ralf Baechle (ralf@linux-mips.org)
- * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
- */
-#include <linux/kernel.h>
-#include <linux/export.h>
-#include <linux/pci.h>
-#include <linux/smp.h>
-#include <linux/dma-direct.h>
-#include <asm/sn/arch.h>
-#include <asm/pci/bridge.h>
-#include <asm/paccess.h>
-#include <asm/sn/intr.h>
-#include <asm/sn/sn0/hub.h>
-
-/*
- * Max #PCI busses we can handle; ie, max #PCI bridges.
- */
-#define MAX_PCI_BUSSES		40
-
-/*
- * XXX: No kmalloc available when we do our crosstalk scan,
- *	we should try to move it later in the boot process.
- */
-static struct bridge_controller bridges[MAX_PCI_BUSSES];
-
-extern struct pci_ops bridge_pci_ops;
-
-int bridge_probe(nasid_t nasid, int widget_id, int masterwid)
-{
-	unsigned long offset = NODE_OFFSET(nasid);
-	struct bridge_controller *bc;
-	static int num_bridges = 0;
-	int slot;
-
-	pci_set_flags(PCI_PROBE_ONLY);
-
-	printk("a bridge\n");
-
-	/* XXX: kludge alert.. */
-	if (!num_bridges)
-		ioport_resource.end = ~0UL;
-
-	bc = &bridges[num_bridges];
-
-	bc->pc.pci_ops		= &bridge_pci_ops;
-	bc->pc.mem_resource	= &bc->mem;
-	bc->pc.io_resource	= &bc->io;
-
-	bc->pc.index		= num_bridges;
-
-	bc->mem.name		= "Bridge PCI MEM";
-	bc->pc.mem_offset	= offset;
-	bc->mem.start		= 0;
-	bc->mem.end		= ~0UL;
-	bc->mem.flags		= IORESOURCE_MEM;
-
-	bc->io.name		= "Bridge IO MEM";
-	bc->pc.io_offset	= offset;
-	bc->io.start		= 0UL;
-	bc->io.end		= ~0UL;
-	bc->io.flags		= IORESOURCE_IO;
-
-	bc->widget_id = widget_id;
-	bc->nasid = nasid;
-
-	bc->baddr = (u64)masterwid << 60 | PCI64_ATTR_BAR;
-
-	/*
-	 * point to this bridge
-	 */
-	bc->base = (struct bridge_regs *)RAW_NODE_SWIN_BASE(nasid, widget_id);
-
-	/*
-	 * Clear all pending interrupts.
-	 */
-	bridge_write(bc, b_int_rst_stat, BRIDGE_IRR_ALL_CLR);
-
-	/*
-	 * Until otherwise set up, assume all interrupts are from slot 0
-	 */
-	bridge_write(bc, b_int_device, 0x0);
-
-	/*
-	 * swap pio's to pci mem and io space (big windows)
-	 */
-	bridge_set(bc, b_wid_control, BRIDGE_CTRL_IO_SWAP |
-				      BRIDGE_CTRL_MEM_SWAP);
-#ifdef CONFIG_PAGE_SIZE_4KB
-	bridge_clr(bc, b_wid_control, BRIDGE_CTRL_PAGE_SIZE);
-#else /* 16kB or larger */
-	bridge_set(bc, b_wid_control, BRIDGE_CTRL_PAGE_SIZE);
-#endif
-
-	/*
-	 * Hmm...  IRIX sets additional bits in the address which
-	 * are documented as reserved in the bridge docs.
-	 */
-	bridge_write(bc, b_wid_int_upper, 0x8000 | (masterwid << 16));
-	bridge_write(bc, b_wid_int_lower, 0x01800090); /* PI_INT_PEND_MOD off*/
-	bridge_write(bc, b_dir_map, (masterwid << 20));	/* DMA */
-	bridge_write(bc, b_int_enable, 0);
-
-	for (slot = 0; slot < 8; slot ++) {
-		bridge_set(bc, b_device[slot].reg, BRIDGE_DEV_SWAP_DIR);
-		bc->pci_int[slot] = -1;
-	}
-	bridge_read(bc, b_wid_tflush);	  /* wait until Bridge PIO complete */
-
-	register_pci_controller(&bc->pc);
-
-	num_bridges++;
-
-	return 0;
-}
-
-/*
- * All observed requests have pin == 1. We could have a global here, that
- * gets incremented and returned every time - unfortunately, pci_map_irq
- * may be called on the same device over and over, and need to return the
- * same value. On O2000, pin can be 0 or 1, and PCI slots can be [0..7].
- *
- * A given PCI device, in general, should be able to intr any of the cpus
- * on any one of the hubs connected to its xbow.
- */
-int pcibios_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
-{
-	return 0;
-}
-
-static inline struct pci_dev *bridge_root_dev(struct pci_dev *dev)
-{
-	while (dev->bus->parent) {
-		/* Move up the chain of bridges. */
-		dev = dev->bus->self;
-	}
-
-	return dev;
-}
-
-/* Do platform specific device initialization at pci_enable_device() time */
-int pcibios_plat_dev_init(struct pci_dev *dev)
-{
-	struct bridge_controller *bc = BRIDGE_CONTROLLER(dev->bus);
-	struct pci_dev *rdev = bridge_root_dev(dev);
-	int slot = PCI_SLOT(rdev->devfn);
-	int irq;
-
-	irq = bc->pci_int[slot];
-	if (irq == -1) {
-		irq = request_bridge_irq(bc, slot);
-		if (irq < 0)
-			return irq;
-
-		bc->pci_int[slot] = irq;
-	}
-	dev->irq = irq;
-
-	return 0;
-}
-
-/*
- * Device might live on a subordinate PCI bus.	XXX Walk up the chain of buses
- * to find the slot number in sense of the bridge device register.
- * XXX This also means multiple devices might rely on conflicting bridge
- * settings.
- */
-
-static inline void pci_disable_swapping(struct pci_dev *dev)
-{
-	struct bridge_controller *bc = BRIDGE_CONTROLLER(dev->bus);
-	struct bridge_regs *bridge = bc->base;
-	int slot = PCI_SLOT(dev->devfn);
-
-	/* Turn off byte swapping */
-	bridge->b_device[slot].reg &= ~BRIDGE_DEV_SWAP_DIR;
-	bridge->b_widget.w_tflush;	/* Flush */
-}
-
-static void pci_fixup_ioc3(struct pci_dev *d)
-{
-	pci_disable_swapping(d);
-}
-
-DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_SGI, PCI_DEVICE_ID_SGI_IOC3,
-	pci_fixup_ioc3);
diff --git a/arch/mips/sgi-ip27/ip27-init.c b/arch/mips/sgi-ip27/ip27-init.c
index 6074efeff894..066b33f50bcc 100644
--- a/arch/mips/sgi-ip27/ip27-init.c
+++ b/arch/mips/sgi-ip27/ip27-init.c
@@ -184,5 +184,7 @@ void __init plat_mem_setup(void)
 
 	ioc3_eth_init();
 
+	ioport_resource.start = 0;
+	ioport_resource.end = ~0UL;
 	set_io_port_base(IO_BASE);
 }
diff --git a/arch/mips/sgi-ip27/ip27-xtalk.c b/arch/mips/sgi-ip27/ip27-xtalk.c
index ce06aaa115ae..bd5cb855c6e5 100644
--- a/arch/mips/sgi-ip27/ip27-xtalk.c
+++ b/arch/mips/sgi-ip27/ip27-xtalk.c
@@ -9,6 +9,9 @@
 
 #include <linux/kernel.h>
 #include <linux/smp.h>
+#include <linux/platform_device.h>
+#include <linux/platform_data/xtalk-bridge.h>
+#include <asm/sn/addrs.h>
 #include <asm/sn/types.h>
 #include <asm/sn/klconfig.h>
 #include <asm/sn/hub.h>
@@ -20,7 +23,48 @@
 #define XXBOW_WIDGET_PART_NUM	0xd000	/* Xbow in Xbridge */
 #define BASE_XBOW_PORT		8     /* Lowest external port */
 
-extern int bridge_probe(nasid_t nasid, int widget, int masterwid);
+static void bridge_platform_create(nasid_t nasid, int widget, int masterwid)
+{
+	struct xtalk_bridge_platform_data *bd;
+	struct platform_device *pdev;
+	unsigned long offset;
+
+	bd = kzalloc(sizeof(*bd), GFP_KERNEL);
+	if (!bd)
+		goto no_mem;
+	pdev = platform_device_alloc("xtalk-bridge", PLATFORM_DEVID_AUTO);
+	if (!pdev) {
+		kfree(bd);
+		goto no_mem;
+	}
+
+	offset = NODE_OFFSET(nasid);
+
+	bd->bridge_addr = RAW_NODE_SWIN_BASE(nasid, widget);
+	bd->intr_addr	= BIT_ULL(47) + 0x01800000 + PI_INT_PEND_MOD;
+	bd->nasid	= nasid;
+	bd->masterwid	= masterwid;
+
+	bd->mem.name	= "Bridge PCI MEM";
+	bd->mem.start	= offset + (widget << SWIN_SIZE_BITS);
+	bd->mem.end	= bd->mem.start + SWIN_SIZE - 1;
+	bd->mem.flags	= IORESOURCE_MEM;
+	bd->mem_offset	= offset;
+
+	bd->io.name	= "Bridge PCI IO";
+	bd->io.start	= offset + (widget << SWIN_SIZE_BITS);
+	bd->io.end	= bd->io.start + SWIN_SIZE - 1;
+	bd->io.flags	= IORESOURCE_IO;
+	bd->io_offset	= offset;
+
+	platform_device_add_data(pdev, bd, sizeof(*bd));
+	platform_device_add(pdev);
+	pr_info("xtalk:n%d/%x bridge widget\n", nasid, widget);
+	return;
+
+no_mem:
+	pr_warn("xtalk:n%d/%x bridge create out of memory\n", nasid, widget);
+}
 
 static int probe_one_port(nasid_t nasid, int widget, int masterwid)
 {
@@ -31,13 +75,10 @@ static int probe_one_port(nasid_t nasid, int widget, int masterwid)
 		(RAW_NODE_SWIN_BASE(nasid, widget) + WIDGET_ID);
 	partnum = XWIDGET_PART_NUM(widget_id);
 
-	printk(KERN_INFO "Cpu %d, Nasid 0x%x, widget 0x%x (partnum 0x%x) is ",
-			smp_processor_id(), nasid, widget, partnum);
-
 	switch (partnum) {
 	case BRIDGE_WIDGET_PART_NUM:
 	case XBRIDGE_WIDGET_PART_NUM:
-		bridge_probe(nasid, widget, masterwid);
+		bridge_platform_create(nasid, widget, masterwid);
 		break;
 	default:
 		break;
@@ -52,8 +93,6 @@ static int xbow_probe(nasid_t nasid)
 	klxbow_t *xbow_p;
 	unsigned masterwid, i;
 
-	printk("is xbow\n");
-
 	/*
 	 * found xbow, so may have multiple bridges
 	 * need to probe xbow
@@ -117,19 +156,17 @@ static void xtalk_probe_node(cnodeid_t nid)
 		       (RAW_NODE_SWIN_BASE(nasid, 0x0) + WIDGET_ID);
 	partnum = XWIDGET_PART_NUM(widget_id);
 
-	printk(KERN_INFO "Cpu %d, Nasid 0x%x: partnum 0x%x is ",
-			smp_processor_id(), nasid, partnum);
-
 	switch (partnum) {
 	case BRIDGE_WIDGET_PART_NUM:
-		bridge_probe(nasid, 0x8, 0xa);
+		bridge_platform_create(nasid, 0x8, 0xa);
 		break;
 	case XBOW_WIDGET_PART_NUM:
 	case XXBOW_WIDGET_PART_NUM:
+		pr_info("xtalk:n%d/0 xbow widget\n", nasid);
 		xbow_probe(nasid);
 		break;
 	default:
-		printk(" unknown widget??\n");
+		pr_info("xtalk:n%d/0 unknown widget (0x%x)\n", nasid, partnum);
 		break;
 	}
 }
diff --git a/drivers/pci/controller/Kconfig b/drivers/pci/controller/Kconfig
index 6012f3059acd..bc92471a72d2 100644
--- a/drivers/pci/controller/Kconfig
+++ b/drivers/pci/controller/Kconfig
@@ -265,6 +265,9 @@ config PCIE_TANGO_SMP8759
 	  This can lead to data corruption if drivers perform concurrent
 	  config and MMIO accesses.
 
+config PCI_XTALK_BRIDGE
+	bool
+
 config VMD
 	depends on PCI_MSI && X86_64 && SRCU
 	tristate "Intel Volume Management Device Driver"
diff --git a/drivers/pci/controller/Makefile b/drivers/pci/controller/Makefile
index d56a507495c5..bcbd740f878c 100644
--- a/drivers/pci/controller/Makefile
+++ b/drivers/pci/controller/Makefile
@@ -28,6 +28,7 @@ obj-$(CONFIG_PCIE_ROCKCHIP_HOST) += pcie-rockchip-host.o
 obj-$(CONFIG_PCIE_MEDIATEK) += pcie-mediatek.o
 obj-$(CONFIG_PCIE_MOBIVEIL) += pcie-mobiveil.o
 obj-$(CONFIG_PCIE_TANGO_SMP8759) += pcie-tango.o
+obj-$(CONFIG_PCI_XTALK_BRIDGE) += pci-xtalk-bridge.o
 obj-$(CONFIG_VMD) += vmd.o
 # pcie-hisi.o quirks are needed even without CONFIG_PCIE_DW
 obj-y				+= dwc/
diff --git a/drivers/pci/controller/pci-xtalk-bridge.c b/drivers/pci/controller/pci-xtalk-bridge.c
new file mode 100644
index 000000000000..8f481984ab6e
--- /dev/null
+++ b/drivers/pci/controller/pci-xtalk-bridge.c
@@ -0,0 +1,452 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2003 Christoph Hellwig (hch@lst.de)
+ * Copyright (C) 1999, 2000, 04 Ralf Baechle (ralf@linux-mips.org)
+ * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
+ */
+#include <linux/kernel.h>
+#include <linux/export.h>
+#include <linux/pci.h>
+#include <linux/smp.h>
+#include <linux/dma-direct.h>
+#include <linux/platform_device.h>
+#include <linux/platform_data/xtalk-bridge.h>
+
+#include <asm/pci/bridge.h>
+#include <asm/paccess.h>
+#include <asm/sn/intr.h>
+
+/*
+ * Most of the IOC3 PCI config register aren't present
+ * we emulate what is needed for a normal PCI enumeration
+ */
+static u32 emulate_ioc3_cfg(int where, int size)
+{
+	if (size == 1 && where == 0x3d)
+		return 0x01;
+	else if (size == 2 && where == 0x3c)
+		return 0x0100;
+	else if (size == 4 && where == 0x3c)
+		return 0x00000100;
+
+	return 0;
+}
+
+static void bridge_disable_swapping(struct pci_dev *dev)
+{
+	struct bridge_controller *bc = BRIDGE_CONTROLLER(dev->bus);
+	int slot = PCI_SLOT(dev->devfn);
+
+	/* Turn off byte swapping */
+	bridge_clr(bc, b_device[slot].reg, BRIDGE_DEV_SWAP_DIR);
+	bridge_read(bc, b_widget.w_tflush);	/* Flush */
+}
+
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_SGI, PCI_DEVICE_ID_SGI_IOC3,
+	bridge_disable_swapping);
+
+
+/*
+ * The Bridge ASIC supports both type 0 and type 1 access.  Type 1 is
+ * not really documented, so right now I can't write code which uses it.
+ * Therefore we use type 0 accesses for now even though they won't work
+ * correctly for PCI-to-PCI bridges.
+ *
+ * The function is complicated by the ultimate brokenness of the IOC3 chip
+ * which is used in SGI systems.  The IOC3 can only handle 32-bit PCI
+ * accesses and does only decode parts of it's address space.
+ */
+static int pci_conf0_read_config(struct pci_bus *bus, unsigned int devfn,
+				 int where, int size, u32 *value)
+{
+	struct bridge_controller *bc = BRIDGE_CONTROLLER(bus);
+	struct bridge_regs *bridge = bc->base;
+	int slot = PCI_SLOT(devfn);
+	int fn = PCI_FUNC(devfn);
+	void *addr;
+	u32 cf, shift, mask;
+	int res;
+
+	addr = &bridge->b_type0_cfg_dev[slot].f[fn].c[PCI_VENDOR_ID];
+	if (get_dbe(cf, (u32 *)addr))
+		return PCIBIOS_DEVICE_NOT_FOUND;
+
+	/*
+	 * IOC3 is broken beyond belief ...  Don't even give the
+	 * generic PCI code a chance to look at it for real ...
+	 */
+	if (cf == (PCI_VENDOR_ID_SGI | (PCI_DEVICE_ID_SGI_IOC3 << 16)))
+		goto is_ioc3;
+
+	addr = &bridge->b_type0_cfg_dev[slot].f[fn].c[where ^ (4 - size)];
+
+	if (size == 1)
+		res = get_dbe(*value, (u8 *)addr);
+	else if (size == 2)
+		res = get_dbe(*value, (u16 *)addr);
+	else
+		res = get_dbe(*value, (u32 *)addr);
+
+	return res ? PCIBIOS_DEVICE_NOT_FOUND : PCIBIOS_SUCCESSFUL;
+
+is_ioc3:
+
+	/*
+	 * IOC3 special handling
+	 */
+	if ((where >= 0x14 && where < 0x40) || (where >= 0x48)) {
+		*value = emulate_ioc3_cfg(where, size);
+		return PCIBIOS_SUCCESSFUL;
+	}
+
+	addr = &bridge->b_type0_cfg_dev[slot].f[fn].l[where >> 2];
+	if (get_dbe(cf, (u32 *)addr))
+		return PCIBIOS_DEVICE_NOT_FOUND;
+
+	shift = ((where & 3) << 3);
+	mask = (0xffffffffU >> ((4 - size) << 3));
+	*value = (cf >> shift) & mask;
+
+	return PCIBIOS_SUCCESSFUL;
+}
+
+static int pci_conf1_read_config(struct pci_bus *bus, unsigned int devfn,
+				 int where, int size, u32 *value)
+{
+	struct bridge_controller *bc = BRIDGE_CONTROLLER(bus);
+	struct bridge_regs *bridge = bc->base;
+	int busno = bus->number;
+	int slot = PCI_SLOT(devfn);
+	int fn = PCI_FUNC(devfn);
+	void *addr;
+	u32 cf, shift, mask;
+	int res;
+
+	bridge_write(bc, b_pci_cfg, (busno << 16) | (slot << 11));
+	addr = &bridge->b_type1_cfg.c[(fn << 8) | PCI_VENDOR_ID];
+	if (get_dbe(cf, (u32 *)addr))
+		return PCIBIOS_DEVICE_NOT_FOUND;
+
+	/*
+	 * IOC3 is broken beyond belief ...  Don't even give the
+	 * generic PCI code a chance to look at it for real ...
+	 */
+	if (cf == (PCI_VENDOR_ID_SGI | (PCI_DEVICE_ID_SGI_IOC3 << 16)))
+		goto is_ioc3;
+
+	addr = &bridge->b_type1_cfg.c[(fn << 8) | (where ^ (4 - size))];
+
+	if (size == 1)
+		res = get_dbe(*value, (u8 *)addr);
+	else if (size == 2)
+		res = get_dbe(*value, (u16 *)addr);
+	else
+		res = get_dbe(*value, (u32 *)addr);
+
+	return res ? PCIBIOS_DEVICE_NOT_FOUND : PCIBIOS_SUCCESSFUL;
+
+is_ioc3:
+
+	/*
+	 * IOC3 special handling
+	 */
+	if ((where >= 0x14 && where < 0x40) || (where >= 0x48)) {
+		*value = emulate_ioc3_cfg(where, size);
+		return PCIBIOS_SUCCESSFUL;
+	}
+
+	addr = &bridge->b_type1_cfg.c[(fn << 8) | where];
+	if (get_dbe(cf, (u32 *)addr))
+		return PCIBIOS_DEVICE_NOT_FOUND;
+
+	shift = ((where & 3) << 3);
+	mask = (0xffffffffU >> ((4 - size) << 3));
+	*value = (cf >> shift) & mask;
+
+	return PCIBIOS_SUCCESSFUL;
+}
+
+static int pci_read_config(struct pci_bus *bus, unsigned int devfn,
+			   int where, int size, u32 *value)
+{
+	if (!pci_is_root_bus(bus))
+		return pci_conf1_read_config(bus, devfn, where, size, value);
+
+	return pci_conf0_read_config(bus, devfn, where, size, value);
+}
+
+static int pci_conf0_write_config(struct pci_bus *bus, unsigned int devfn,
+				  int where, int size, u32 value)
+{
+	struct bridge_controller *bc = BRIDGE_CONTROLLER(bus);
+	struct bridge_regs *bridge = bc->base;
+	int slot = PCI_SLOT(devfn);
+	int fn = PCI_FUNC(devfn);
+	void *addr;
+	u32 cf, shift, mask, smask;
+	int res;
+
+	addr = &bridge->b_type0_cfg_dev[slot].f[fn].c[PCI_VENDOR_ID];
+	if (get_dbe(cf, (u32 *)addr))
+		return PCIBIOS_DEVICE_NOT_FOUND;
+
+	/*
+	 * IOC3 is broken beyond belief ...  Don't even give the
+	 * generic PCI code a chance to look at it for real ...
+	 */
+	if (cf == (PCI_VENDOR_ID_SGI | (PCI_DEVICE_ID_SGI_IOC3 << 16)))
+		goto is_ioc3;
+
+	addr = &bridge->b_type0_cfg_dev[slot].f[fn].c[where ^ (4 - size)];
+
+	if (size == 1)
+		res = put_dbe(value, (u8 *)addr);
+	else if (size == 2)
+		res = put_dbe(value, (u16 *)addr);
+	else
+		res = put_dbe(value, (u32 *)addr);
+
+	if (res)
+		return PCIBIOS_DEVICE_NOT_FOUND;
+
+	return PCIBIOS_SUCCESSFUL;
+
+is_ioc3:
+
+	/*
+	 * IOC3 special handling
+	 */
+	if ((where >= 0x14 && where < 0x40) || (where >= 0x48))
+		return PCIBIOS_SUCCESSFUL;
+
+	addr = &bridge->b_type0_cfg_dev[slot].f[fn].l[where >> 2];
+
+	if (get_dbe(cf, (u32 *)addr))
+		return PCIBIOS_DEVICE_NOT_FOUND;
+
+	shift = ((where & 3) << 3);
+	mask = (0xffffffffU >> ((4 - size) << 3));
+	smask = mask << shift;
+
+	cf = (cf & ~smask) | ((value & mask) << shift);
+	if (put_dbe(cf, (u32 *)addr))
+		return PCIBIOS_DEVICE_NOT_FOUND;
+
+	return PCIBIOS_SUCCESSFUL;
+}
+
+static int pci_conf1_write_config(struct pci_bus *bus, unsigned int devfn,
+				  int where, int size, u32 value)
+{
+	struct bridge_controller *bc = BRIDGE_CONTROLLER(bus);
+	struct bridge_regs *bridge = bc->base;
+	int slot = PCI_SLOT(devfn);
+	int fn = PCI_FUNC(devfn);
+	int busno = bus->number;
+	void *addr;
+	u32 cf, shift, mask, smask;
+	int res;
+
+	bridge_write(bc, b_pci_cfg, (busno << 16) | (slot << 11));
+	addr = &bridge->b_type1_cfg.c[(fn << 8) | PCI_VENDOR_ID];
+	if (get_dbe(cf, (u32 *)addr))
+		return PCIBIOS_DEVICE_NOT_FOUND;
+
+	/*
+	 * IOC3 is broken beyond belief ...  Don't even give the
+	 * generic PCI code a chance to look at it for real ...
+	 */
+	if (cf == (PCI_VENDOR_ID_SGI | (PCI_DEVICE_ID_SGI_IOC3 << 16)))
+		goto is_ioc3;
+
+	addr = &bridge->b_type1_cfg.c[(fn << 8) | (where ^ (4 - size))];
+
+	if (size == 1)
+		res = put_dbe(value, (u8 *)addr);
+	else if (size == 2)
+		res = put_dbe(value, (u16 *)addr);
+	else
+		res = put_dbe(value, (u32 *)addr);
+
+	if (res)
+		return PCIBIOS_DEVICE_NOT_FOUND;
+
+	return PCIBIOS_SUCCESSFUL;
+
+is_ioc3:
+
+	/*
+	 * IOC3 special handling
+	 */
+	if ((where >= 0x14 && where < 0x40) || (where >= 0x48))
+		return PCIBIOS_SUCCESSFUL;
+
+	addr = &bridge->b_type0_cfg_dev[slot].f[fn].l[where >> 2];
+	if (get_dbe(cf, (u32 *)addr))
+		return PCIBIOS_DEVICE_NOT_FOUND;
+
+	shift = ((where & 3) << 3);
+	mask = (0xffffffffU >> ((4 - size) << 3));
+	smask = mask << shift;
+
+	cf = (cf & ~smask) | ((value & mask) << shift);
+	if (put_dbe(cf, (u32 *)addr))
+		return PCIBIOS_DEVICE_NOT_FOUND;
+
+	return PCIBIOS_SUCCESSFUL;
+}
+
+static int pci_write_config(struct pci_bus *bus, unsigned int devfn,
+	int where, int size, u32 value)
+{
+	if (!pci_is_root_bus(bus))
+		return pci_conf1_write_config(bus, devfn, where, size, value);
+
+	return pci_conf0_write_config(bus, devfn, where, size, value);
+}
+
+static struct pci_ops bridge_pci_ops = {
+	.read	 = pci_read_config,
+	.write	 = pci_write_config,
+};
+
+/*
+ * All observed requests have pin == 1. We could have a global here, that
+ * gets incremented and returned every time - unfortunately, pci_map_irq
+ * may be called on the same device over and over, and need to return the
+ * same value. On O2000, pin can be 0 or 1, and PCI slots can be [0..7].
+ *
+ * A given PCI device, in general, should be able to intr any of the cpus
+ * on any one of the hubs connected to its xbow.
+ */
+static int bridge_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
+{
+	struct bridge_controller *bc = BRIDGE_CONTROLLER(dev->bus);
+	int irq;
+
+	irq = bc->pci_int[slot];
+	if (irq == -1) {
+		irq = request_bridge_irq(bc, slot);
+		if (irq < 0)
+			return irq;
+
+		bc->pci_int[slot] = irq;
+	}
+	return irq;
+}
+
+static int bridge_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct bridge_controller *bc;
+	struct pci_host_bridge *host;
+	int slot;
+	int err;
+	struct xtalk_bridge_platform_data *bd = dev_get_platdata(&pdev->dev);
+
+	pci_set_flags(PCI_PROBE_ONLY);
+
+	host = devm_pci_alloc_host_bridge(dev, sizeof(*bc));
+	if (!host)
+		return -ENOMEM;
+
+	bc = pci_host_bridge_priv(host);
+
+	bc->busn.name		= "Bridge PCI busn";
+	bc->busn.start		= 0;
+	bc->busn.end		= 0xff;
+	bc->busn.flags		= IORESOURCE_BUS;
+
+	pci_add_resource_offset(&host->windows, &bd->mem, bd->mem_offset);
+	pci_add_resource_offset(&host->windows, &bd->io, bd->io_offset);
+	pci_add_resource(&host->windows, &bc->busn);
+
+	err = devm_request_pci_bus_resources(dev, &host->windows);
+	if (err < 0) {
+		pci_free_resource_list(&host->windows);
+		return err;
+	}
+
+	bc->nasid = bd->nasid;
+
+	bc->baddr = (u64)bd->masterwid << 60 | PCI64_ATTR_BAR;
+	bc->base = (struct bridge_regs *)bd->bridge_addr;
+	bc->intr_addr = bd->intr_addr;
+
+	/*
+	 * Clear all pending interrupts.
+	 */
+	bridge_write(bc, b_int_rst_stat, BRIDGE_IRR_ALL_CLR);
+
+	/*
+	 * Until otherwise set up, assume all interrupts are from slot 0
+	 */
+	bridge_write(bc, b_int_device, 0x0);
+
+	/*
+	 * disable swapping for big windows
+	 */
+	bridge_clr(bc, b_wid_control,
+		   BRIDGE_CTRL_IO_SWAP | BRIDGE_CTRL_MEM_SWAP);
+#ifdef CONFIG_PAGE_SIZE_4KB
+	bridge_clr(bc, b_wid_control, BRIDGE_CTRL_PAGE_SIZE);
+#else /* 16kB or larger */
+	bridge_set(bc, b_wid_control, BRIDGE_CTRL_PAGE_SIZE);
+#endif
+
+	/*
+	 * Hmm...  IRIX sets additional bits in the address which
+	 * are documented as reserved in the bridge docs.
+	 */
+	bridge_write(bc, b_wid_int_upper,
+		     ((bc->intr_addr >> 32) & 0xffff) | (bd->masterwid << 16));
+	bridge_write(bc, b_wid_int_lower, bc->intr_addr & 0xffffffff);
+	bridge_write(bc, b_dir_map, (bd->masterwid << 20));	/* DMA */
+	bridge_write(bc, b_int_enable, 0);
+
+	for (slot = 0; slot < 8; slot++) {
+		bridge_set(bc, b_device[slot].reg, BRIDGE_DEV_SWAP_DIR);
+		bc->pci_int[slot] = -1;
+	}
+	bridge_read(bc, b_wid_tflush);	  /* wait until Bridge PIO complete */
+
+	host->dev.parent = dev;
+	host->sysdata = bc;
+	host->busnr = 0;
+	host->ops = &bridge_pci_ops;
+	host->map_irq = bridge_map_irq;
+	host->swizzle_irq = pci_common_swizzle;
+
+	err = pci_scan_root_bus_bridge(host);
+	if (err < 0)
+		return err;
+
+	pci_bus_claim_resources(host->bus);
+	pci_bus_add_devices(host->bus);
+
+	platform_set_drvdata(pdev, host->bus);
+
+	return 0;
+}
+
+static int bridge_remove(struct platform_device *pdev)
+{
+	struct pci_bus *bus = platform_get_drvdata(pdev);
+
+	pci_lock_rescan_remove();
+	pci_stop_root_bus(bus);
+	pci_remove_root_bus(bus);
+	pci_unlock_rescan_remove();
+
+	return 0;
+}
+
+static struct platform_driver bridge_driver = {
+	.probe  = bridge_probe,
+	.remove = bridge_remove,
+	.driver = {
+		.name = "xtalk-bridge",
+	}
+};
+
+builtin_platform_driver(bridge_driver);
diff --git a/include/linux/platform_data/xtalk-bridge.h b/include/linux/platform_data/xtalk-bridge.h
new file mode 100644
index 000000000000..51e5001f2c05
--- /dev/null
+++ b/include/linux/platform_data/xtalk-bridge.h
@@ -0,0 +1,22 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * SGI PCI Xtalk Bridge
+ */
+
+#ifndef PLATFORM_DATA_XTALK_BRIDGE_H
+#define PLATFORM_DATA_XTALK_BRIDGE_H
+
+#include <asm/sn/types.h>
+
+struct xtalk_bridge_platform_data {
+	struct resource	mem;
+	struct resource io;
+	unsigned long bridge_addr;
+	unsigned long intr_addr;
+	unsigned long mem_offset;
+	unsigned long io_offset;
+	nasid_t	nasid;
+	int	masterwid;
+};
+
+#endif /* PLATFORM_DATA_XTALK_BRIDGE_H */
-- 
2.13.7

[PATCH v3 3/3] MIPS: SGI-IP27: abstract chipset irq from bridge

[Thomas Bogendoerfer]

Bridge ASIC is widely used in different SGI systems, but the connected
chipset is either HUB, HEART or BEDROCK. This commit switches to
irq domain hierarchy for hub and bridge interrupts to get bridge
setup out of hub interrupt code.

Signed-off-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 arch/mips/Kconfig                         |   1 +
 arch/mips/include/asm/pci/bridge.h        |   3 +-
 arch/mips/include/asm/sn/irq_alloc.h      |  11 ++
 arch/mips/sgi-ip27/ip27-irq.c             | 191 +++++++++++++-----------------
 drivers/pci/controller/pci-xtalk-bridge.c | 178 ++++++++++++++++++++++++++--
 5 files changed, 265 insertions(+), 119 deletions(-)
 create mode 100644 arch/mips/include/asm/sn/irq_alloc.h

diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 3f9b42580fd4..2464f7ab07bf 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -676,6 +676,7 @@ config SGI_IP27
 	select SYS_HAS_EARLY_PRINTK
 	select HAVE_PCI
 	select IRQ_MIPS_CPU
+	select IRQ_DOMAIN_HIERARCHY
 	select NR_CPUS_DEFAULT_64
 	select PCI_DRIVERS_GENERIC
 	select PCI_XTALK_BRIDGE
diff --git a/arch/mips/include/asm/pci/bridge.h b/arch/mips/include/asm/pci/bridge.h
index d42b27c97c23..a92cd30b48c9 100644
--- a/arch/mips/include/asm/pci/bridge.h
+++ b/arch/mips/include/asm/pci/bridge.h
@@ -805,6 +805,7 @@ struct bridge_controller {
 	struct bridge_regs	*base;
 	unsigned long		baddr;
 	unsigned long		intr_addr;
+	struct irq_domain	*domain;
 	unsigned int		pci_int[8];
 	nasid_t			nasid;
 };
@@ -819,6 +820,4 @@ struct bridge_controller {
 #define bridge_clr(bc, reg, val)	\
 	__raw_writel(__raw_readl(&bc->base->reg) & ~(val), &bc->base->reg)
 
-extern int request_bridge_irq(struct bridge_controller *bc, int pin);
-
 #endif /* _ASM_PCI_BRIDGE_H */
diff --git a/arch/mips/include/asm/sn/irq_alloc.h b/arch/mips/include/asm/sn/irq_alloc.h
new file mode 100644
index 000000000000..09b89cecff56
--- /dev/null
+++ b/arch/mips/include/asm/sn/irq_alloc.h
@@ -0,0 +1,11 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __ASM_SN_IRQ_ALLOC_H
+#define __ASM_SN_IRQ_ALLOC_H
+
+struct irq_alloc_info {
+	void *ctrl;
+	nasid_t nasid;
+	int pin;
+};
+
+#endif /* __ASM_SN_IRQ_ALLOC_H */
diff --git a/arch/mips/sgi-ip27/ip27-irq.c b/arch/mips/sgi-ip27/ip27-irq.c
index 710a59764b01..37be04975831 100644
--- a/arch/mips/sgi-ip27/ip27-irq.c
+++ b/arch/mips/sgi-ip27/ip27-irq.c
@@ -12,22 +12,20 @@
 #include <linux/ioport.h>
 #include <linux/kernel.h>
 #include <linux/bitops.h>
+#include <linux/sched.h>
 
 #include <asm/io.h>
 #include <asm/irq_cpu.h>
-#include <asm/pci/bridge.h>
 #include <asm/sn/addrs.h>
 #include <asm/sn/agent.h>
 #include <asm/sn/arch.h>
 #include <asm/sn/hub.h>
 #include <asm/sn/intr.h>
+#include <asm/sn/irq_alloc.h>
 
 struct hub_irq_data {
-	struct bridge_controller *bc;
 	u64	*irq_mask[2];
 	cpuid_t	cpu;
-	int	bit;
-	int	pin;
 };
 
 static DECLARE_BITMAP(hub_irq_map, IP27_HUB_IRQ_COUNT);
@@ -54,7 +52,7 @@ static void enable_hub_irq(struct irq_data *d)
 	struct hub_irq_data *hd = irq_data_get_irq_chip_data(d);
 	unsigned long *mask = per_cpu(irq_enable_mask, hd->cpu);
 
-	set_bit(hd->bit, mask);
+	set_bit(d->hwirq, mask);
 	__raw_writeq(mask[0], hd->irq_mask[0]);
 	__raw_writeq(mask[1], hd->irq_mask[1]);
 }
@@ -64,72 +62,11 @@ static void disable_hub_irq(struct irq_data *d)
 	struct hub_irq_data *hd = irq_data_get_irq_chip_data(d);
 	unsigned long *mask = per_cpu(irq_enable_mask, hd->cpu);
 
-	clear_bit(hd->bit, mask);
+	clear_bit(d->hwirq, mask);
 	__raw_writeq(mask[0], hd->irq_mask[0]);
 	__raw_writeq(mask[1], hd->irq_mask[1]);
 }
 
-static unsigned int startup_bridge_irq(struct irq_data *d)
-{
-	struct hub_irq_data *hd = irq_data_get_irq_chip_data(d);
-	struct bridge_controller *bc;
-	nasid_t nasid;
-	u32 device;
-	int pin;
-
-	if (!hd)
-		return -EINVAL;
-
-	pin = hd->pin;
-	bc = hd->bc;
-
-	nasid = COMPACT_TO_NASID_NODEID(cpu_to_node(hd->cpu));
-	bridge_write(bc, b_int_addr[pin].addr,
-		     (0x20000 | hd->bit | (nasid << 8)));
-	bridge_set(bc, b_int_enable, (1 << pin));
-	bridge_set(bc, b_int_enable, 0x7ffffe00); /* more stuff in int_enable */
-
-	/*
-	 * Enable sending of an interrupt clear packt to the hub on a high to
-	 * low transition of the interrupt pin.
-	 *
-	 * IRIX sets additional bits in the address which are documented as
-	 * reserved in the bridge docs.
-	 */
-	bridge_set(bc, b_int_mode, (1UL << pin));
-
-	/*
-	 * We assume the bridge to have a 1:1 mapping between devices
-	 * (slots) and intr pins.
-	 */
-	device = bridge_read(bc, b_int_device);
-	device &= ~(7 << (pin*3));
-	device |= (pin << (pin*3));
-	bridge_write(bc, b_int_device, device);
-
-	bridge_read(bc, b_wid_tflush);
-
-	enable_hub_irq(d);
-
-	return 0;	/* Never anything pending.  */
-}
-
-static void shutdown_bridge_irq(struct irq_data *d)
-{
-	struct hub_irq_data *hd = irq_data_get_irq_chip_data(d);
-	struct bridge_controller *bc;
-	int pin = hd->pin;
-
-	if (!hd)
-		return;
-
-	disable_hub_irq(d);
-
-	bc = hd->bc;
-	bridge_clr(bc, b_int_enable, (1 << pin));
-	bridge_read(bc, b_wid_tflush);
-}
-
 static void setup_hub_mask(struct hub_irq_data *hd, const struct cpumask *mask)
 {
 	nasid_t nasid;
@@ -145,9 +82,6 @@ static void setup_hub_mask(struct hub_irq_data *hd, const struct cpumask *mask)
 		hd->irq_mask[0] = REMOTE_HUB_PTR(nasid, PI_INT_MASK0_B);
 		hd->irq_mask[1] = REMOTE_HUB_PTR(nasid, PI_INT_MASK1_B);
 	}
-
-	/* Make sure it's not already pending when we connect it. */
-	REMOTE_HUB_CLR_INTR(nasid, hd->bit);
 }
 
 static int set_affinity_hub_irq(struct irq_data *d, const struct cpumask *mask,
@@ -164,7 +98,7 @@ static int set_affinity_hub_irq(struct irq_data *d, const struct cpumask *mask,
 	setup_hub_mask(hd, mask);
 
 	if (irqd_is_started(d))
-		startup_bridge_irq(d);
+		enable_hub_irq(d);
 
 	irq_data_update_effective_affinity(d, cpumask_of(hd->cpu));
 
@@ -173,20 +107,22 @@ static int set_affinity_hub_irq(struct irq_data *d, const struct cpumask *mask,
 
 static struct irq_chip hub_irq_type = {
 	.name		  = "HUB",
-	.irq_startup	  = startup_bridge_irq,
-	.irq_shutdown	  = shutdown_bridge_irq,
 	.irq_mask	  = disable_hub_irq,
 	.irq_unmask	  = enable_hub_irq,
 	.irq_set_affinity = set_affinity_hub_irq,
 };
 
-int request_bridge_irq(struct bridge_controller *bc, int pin)
+static int hub_domain_alloc(struct irq_domain *domain, unsigned int virq,
+			    unsigned int nr_irqs, void *arg)
 {
+	struct irq_alloc_info *info = arg;
 	struct hub_irq_data *hd;
 	struct hub_data *hub;
 	struct irq_desc *desc;
 	int swlevel;
-	int irq;
+
+	if (nr_irqs > 1 || !info)
+		return -EINVAL;
 
 	hd = kzalloc(sizeof(*hd), GFP_KERNEL);
 	if (!hd)
@@ -197,46 +133,41 @@ int request_bridge_irq(struct bridge_controller *bc, int pin)
 		kfree(hd);
 		return -EAGAIN;
 	}
-	irq = swlevel + IP27_HUB_IRQ_BASE;
-
-	hd->bc = bc;
-	hd->bit = swlevel;
-	hd->pin = pin;
-	irq_set_chip_data(irq, hd);
+	irq_domain_set_info(domain, virq, swlevel, &hub_irq_type, hd,
+			    handle_level_irq, NULL, NULL);
 
 	/* use CPU connected to nearest hub */
-	hub = hub_data(NASID_TO_COMPACT_NODEID(bc->nasid));
+	hub = hub_data(NASID_TO_COMPACT_NODEID(info->nasid));
 	setup_hub_mask(hd, &hub->h_cpus);
 
-	desc = irq_to_desc(irq);
-	desc->irq_common_data.node = bc->nasid;
+	/* Make sure it's not already pending when we connect it. */
+	REMOTE_HUB_CLR_INTR(info->nasid, swlevel);
+
+	desc = irq_to_desc(virq);
+	desc->irq_common_data.node = info->nasid;
 	cpumask_copy(desc->irq_common_data.affinity, &hub->h_cpus);
 
-	return irq;
+	return 0;
 }
 
-void ip27_hub_irq_init(void)
+static void hub_domain_free(struct irq_domain *domain,
+			    unsigned int virq, unsigned int nr_irqs)
 {
-	int i;
+	struct irq_data *irqd;
 
-	for (i = IP27_HUB_IRQ_BASE;
-	     i < (IP27_HUB_IRQ_BASE + IP27_HUB_IRQ_COUNT); i++)
-		irq_set_chip_and_handler(i, &hub_irq_type, handle_level_irq);
-
-	/*
-	 * Some interrupts are reserved by hardware or by software convention.
-	 * Mark these as reserved right away so they won't be used accidentally
-	 * later.
-	 */
-	for (i = 0; i <= BASE_PCI_IRQ; i++)
-		set_bit(i, hub_irq_map);
-
-	set_bit(IP_PEND0_6_63, hub_irq_map);
+	if (nr_irqs > 1)
+		return;
 
-	for (i = NI_BRDCAST_ERR_A; i <= MSC_PANIC_INTR; i++)
-		set_bit(i, hub_irq_map);
+	irqd = irq_domain_get_irq_data(domain, virq);
+	if (irqd && irqd->chip_data)
+		kfree(irqd->chip_data);
 }
 
+static const struct irq_domain_ops hub_domain_ops = {
+	.alloc = hub_domain_alloc,
+	.free  = hub_domain_free,
+};
+
 /*
  * This code is unnecessarily complex, because we do
  * intr enabling. Basically, once we grab the set of intrs we need
@@ -253,7 +184,9 @@ static void ip27_do_irq_mask0(struct irq_desc *desc)
 {
 	cpuid_t cpu = smp_processor_id();
 	unsigned long *mask = per_cpu(irq_enable_mask, cpu);
+	struct irq_domain *domain;
 	u64 pend0;
+	int irq;
 
 	/* copied from Irix intpend0() */
 	pend0 = LOCAL_HUB_L(PI_INT_PEND0);
@@ -277,7 +210,14 @@ static void ip27_do_irq_mask0(struct irq_desc *desc)
 		generic_smp_call_function_interrupt();
 	} else
 #endif
-		generic_handle_irq(__ffs(pend0) + IP27_HUB_IRQ_BASE);
+	{
+		domain = irq_desc_get_handler_data(desc);
+		irq = irq_linear_revmap(domain, __ffs(pend0));
+		if (irq)
+			generic_handle_irq(irq);
+		else
+			spurious_interrupt();
+	}
 
 	LOCAL_HUB_L(PI_INT_PEND0);
 }
@@ -286,7 +226,9 @@ static void ip27_do_irq_mask1(struct irq_desc *desc)
 {
 	cpuid_t cpu = smp_processor_id();
 	unsigned long *mask = per_cpu(irq_enable_mask, cpu);
+	struct irq_domain *domain;
 	u64 pend1;
+	int irq;
 
 	/* copied from Irix intpend0() */
 	pend1 = LOCAL_HUB_L(PI_INT_PEND1);
@@ -295,7 +237,12 @@ static void ip27_do_irq_mask1(struct irq_desc *desc)
 	if (!pend1)
 		return;
 
-	generic_handle_irq(__ffs(pend1) + IP27_HUB_IRQ_BASE + 64);
+	domain = irq_desc_get_handler_data(desc);
+	irq = irq_linear_revmap(domain, __ffs(pend1) + 64);
+	if (irq)
+		generic_handle_irq(irq);
+	else
+		spurious_interrupt();
 
 	LOCAL_HUB_L(PI_INT_PEND1);
 }
@@ -326,11 +273,41 @@ void install_ipi(void)
 
 void __init arch_init_irq(void)
 {
+	struct irq_domain *domain;
+	struct fwnode_handle *fn;
+	int i;
+
 	mips_cpu_irq_init();
-	ip27_hub_irq_init();
+
+	/*
+	 * Some interrupts are reserved by hardware or by software convention.
+	 * Mark these as reserved right away so they won't be used accidentally
+	 * later.
+	 */
+	for (i = 0; i <= BASE_PCI_IRQ; i++)
+		set_bit(i, hub_irq_map);
+
+	set_bit(IP_PEND0_6_63, hub_irq_map);
+
+	for (i = NI_BRDCAST_ERR_A; i <= MSC_PANIC_INTR; i++)
+		set_bit(i, hub_irq_map);
+
+	fn = irq_domain_alloc_named_fwnode("HUB");
+	WARN_ON(fn == NULL);
+	if (!fn)
+		return;
+	domain = irq_domain_create_linear(fn, IP27_HUB_IRQ_COUNT,
+					  &hub_domain_ops, NULL);
+	WARN_ON(domain == NULL);
+	if (!domain)
+		return;
+
+	irq_set_default_host(domain);
 
 	irq_set_percpu_devid(IP27_HUB_PEND0_IRQ);
-	irq_set_chained_handler(IP27_HUB_PEND0_IRQ, ip27_do_irq_mask0);
+	irq_set_chained_handler_and_data(IP27_HUB_PEND0_IRQ, ip27_do_irq_mask0,
+					 domain);
 	irq_set_percpu_devid(IP27_HUB_PEND1_IRQ);
-	irq_set_chained_handler(IP27_HUB_PEND1_IRQ, ip27_do_irq_mask1);
+	irq_set_chained_handler_and_data(IP27_HUB_PEND1_IRQ, ip27_do_irq_mask1,
+					 domain);
 }
diff --git a/drivers/pci/controller/pci-xtalk-bridge.c b/drivers/pci/controller/pci-xtalk-bridge.c
index 8f481984ab6e..bcf7f559789a 100644
--- a/drivers/pci/controller/pci-xtalk-bridge.c
+++ b/drivers/pci/controller/pci-xtalk-bridge.c
@@ -14,7 +14,7 @@
 
 #include <asm/pci/bridge.h>
 #include <asm/paccess.h>
-#include <asm/sn/intr.h>
+#include <asm/sn/irq_alloc.h>
 
 /*
  * Most of the IOC3 PCI config register aren't present
@@ -310,6 +310,135 @@ static struct pci_ops bridge_pci_ops = {
 	.write	 = pci_write_config,
 };
 
+struct bridge_irq_chip_data {
+	struct bridge_controller *bc;
+	nasid_t nasid;
+};
+
+static int bridge_set_affinity(struct irq_data *d, const struct cpumask *mask,
+			       bool force)
+{
+#ifdef CONFIG_NUMA
+	struct bridge_irq_chip_data *data = d->chip_data;
+	int bit = d->parent_data->hwirq;
+	int pin = d->hwirq;
+	nasid_t nasid;
+	int ret, cpu;
+
+	ret = irq_chip_set_affinity_parent(d, mask, force);
+	if (ret >= 0) {
+		cpu = cpumask_first_and(mask, cpu_online_mask);
+		nasid = COMPACT_TO_NASID_NODEID(cpu_to_node(cpu));
+		bridge_write(data->bc, b_int_addr[pin].addr,
+			     (((data->bc->intr_addr >> 30) & 0x30000) |
+			      bit | (nasid << 8)));
+		bridge_read(data->bc, b_wid_tflush);
+	}
+	return ret;
+#else
+	return irq_chip_set_affinity_parent(d, mask, force);
+#endif
+}
+
+struct irq_chip bridge_irq_chip = {
+	.name             = "BRIDGE",
+	.irq_mask         = irq_chip_mask_parent,
+	.irq_unmask       = irq_chip_unmask_parent,
+	.irq_set_affinity = bridge_set_affinity
+};
+
+static int bridge_domain_alloc(struct irq_domain *domain, unsigned int virq,
+			       unsigned int nr_irqs, void *arg)
+{
+	struct bridge_irq_chip_data *data;
+	struct irq_alloc_info *info = arg;
+	int ret;
+
+	if (nr_irqs > 1 || !info)
+		return -EINVAL;
+
+	data = kzalloc(sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	ret = irq_domain_alloc_irqs_parent(domain, virq, nr_irqs, arg);
+	if (ret >= 0) {
+		data->bc = info->ctrl;
+		data->nasid = info->nasid;
+		irq_domain_set_info(domain, virq, info->pin, &bridge_irq_chip,
+				    data, handle_level_irq, NULL, NULL);
+	} else {
+		kfree(data);
+	}
+
+	return ret;
+}
+
+static void bridge_domain_free(struct irq_domain *domain, unsigned int virq,
+			       unsigned int nr_irqs)
+{
+	struct irq_data *irqd = irq_domain_get_irq_data(domain, virq);
+
+	if (nr_irqs)
+		return;
+
+	kfree(irqd->chip_data);
+	irq_domain_free_irqs_top(domain, virq, nr_irqs);
+}
+
+static int bridge_domain_activate(struct irq_domain *domain,
+				  struct irq_data *irqd, bool reserve)
+{
+	struct bridge_irq_chip_data *data = irqd->chip_data;
+	struct bridge_controller *bc = data->bc;
+	int bit = irqd->parent_data->hwirq;
+	int pin = irqd->hwirq;
+	u32 device;
+
+	bridge_write(bc, b_int_addr[pin].addr,
+		     (((bc->intr_addr >> 30) & 0x30000) |
+		      bit | (data->nasid << 8)));
+	bridge_set(bc, b_int_enable, (1 << pin));
+	bridge_set(bc, b_int_enable, 0x7ffffe00); /* more stuff in int_enable */
+
+	/*
+	 * Enable sending of an interrupt clear packt to the hub on a high to
+	 * low transition of the interrupt pin.
+	 *
+	 * IRIX sets additional bits in the address which are documented as
+	 * reserved in the bridge docs.
+	 */
+	bridge_set(bc, b_int_mode, (1UL << pin));
+
+	/*
+	 * We assume the bridge to have a 1:1 mapping between devices
+	 * (slots) and intr pins.
+	 */
+	device = bridge_read(bc, b_int_device);
+	device &= ~(7 << (pin*3));
+	device |= (pin << (pin*3));
+	bridge_write(bc, b_int_device, device);
+
+	bridge_read(bc, b_wid_tflush);
+	return 0;
+}
+
+static void bridge_domain_deactivate(struct irq_domain *domain,
+				     struct irq_data *irqd)
+{
+	struct bridge_irq_chip_data *data = irqd->chip_data;
+
+	bridge_clr(data->bc, b_int_enable, (1 << irqd->hwirq));
+	bridge_read(data->bc, b_wid_tflush);
+}
+
+static const struct irq_domain_ops bridge_domain_ops = {
+	.alloc      = bridge_domain_alloc,
+	.free       = bridge_domain_free,
+	.activate   = bridge_domain_activate,
+	.deactivate = bridge_domain_deactivate
+};
+
 /*
  * All observed requests have pin == 1. We could have a global here, that
  * gets incremented and returned every time - unfortunately, pci_map_irq
@@ -322,11 +451,16 @@ static struct pci_ops bridge_pci_ops = {
 static int bridge_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
 {
 	struct bridge_controller *bc = BRIDGE_CONTROLLER(dev->bus);
+	struct irq_alloc_info info;
 	int irq;
 
 	irq = bc->pci_int[slot];
 	if (irq == -1) {
-		irq = request_bridge_irq(bc, slot);
+		info.ctrl = bc;
+		info.nasid = bc->nasid;
+		info.pin = slot;
+
+		irq = irq_domain_alloc_irqs(bc->domain, 1, bc->nasid, &info);
 		if (irq < 0)
 			return irq;
 
@@ -337,18 +471,34 @@ static int bridge_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
 
 static int bridge_probe(struct platform_device *pdev)
 {
+	struct xtalk_bridge_platform_data *bd = dev_get_platdata(&pdev->dev);
 	struct device *dev = &pdev->dev;
 	struct bridge_controller *bc;
 	struct pci_host_bridge *host;
+	struct irq_domain *domain, *parent;
+	struct fwnode_handle *fn;
 	int slot;
 	int err;
-	struct xtalk_bridge_platform_data *bd = dev_get_platdata(&pdev->dev);
+
+	parent = irq_get_default_host();
+	if (!parent)
+		return -ENODEV;
+	fn = irq_domain_alloc_named_fwnode("BRIDGE");
+	if (!fn)
+		return -ENOMEM;
+	domain = irq_domain_create_hierarchy(parent, 0, 8, fn,
+					     &bridge_domain_ops, NULL);
+	irq_domain_free_fwnode(fn);
+	if (!domain)
+		return -ENOMEM;
 
 	pci_set_flags(PCI_PROBE_ONLY);
 
 	host = devm_pci_alloc_host_bridge(dev, sizeof(*bc));
-	if (!host)
-		return -ENOMEM;
+	if (!host) {
+		err = -ENOMEM;
+		goto err_remove_domain;
+	}
 
 	bc = pci_host_bridge_priv(host);
 
@@ -357,15 +507,15 @@ static int bridge_probe(struct platform_device *pdev)
 	bc->busn.end		= 0xff;
 	bc->busn.flags		= IORESOURCE_BUS;
 
+	bc->domain		= domain;
+
 	pci_add_resource_offset(&host->windows, &bd->mem, bd->mem_offset);
 	pci_add_resource_offset(&host->windows, &bd->io, bd->io_offset);
 	pci_add_resource(&host->windows, &bc->busn);
 
 	err = devm_request_pci_bus_resources(dev, &host->windows);
-	if (err < 0) {
-		pci_free_resource_list(&host->windows);
-		return err;
-	}
+	if (err < 0)
+		goto err_free_resource;
 
 	bc->nasid = bd->nasid;
 
@@ -419,7 +569,7 @@ static int bridge_probe(struct platform_device *pdev)
 
 	err = pci_scan_root_bus_bridge(host);
 	if (err < 0)
-		return err;
+		goto err_free_resource;
 
 	pci_bus_claim_resources(host->bus);
 	pci_bus_add_devices(host->bus);
@@ -427,12 +577,20 @@ static int bridge_probe(struct platform_device *pdev)
 	platform_set_drvdata(pdev, host->bus);
 
 	return 0;
+
+err_free_resource:
+	pci_free_resource_list(&host->windows);
+err_remove_domain:
+	irq_domain_remove(domain);
+	return err;
 }
 
 static int bridge_remove(struct platform_device *pdev)
 {
 	struct pci_bus *bus = platform_get_drvdata(pdev);
+	struct bridge_controller *bc = BRIDGE_CONTROLLER(bus);
 
+	irq_domain_remove(bc->domain);
 	pci_lock_rescan_remove();
 	pci_stop_root_bus(bus);
 	pci_remove_root_bus(bus);
-- 
2.13.7

[PATCH v3 00/3] MIPS: SGI-IP27 rework part2

[Thomas Bogendoerfer]

SGI IP27 (Origin/Onyx2) and SGI IP30 (Octane) have a similair
architecture and share some hardware (ioc3/bridge). To share
the software parts this patchset reworks SGI IP27 interrupt
and pci bridge code. By using features Linux gained during the
many years since SGI IP27 code was integrated this even results
in code reduction and IMHO cleaner code.

Tests have been done on a two module O200 (4 CPUs) and an
Origin 2000 (8 CPUs).

My next step in integrating SGI IP30 support is splitting ioc3eth
into a MFD and subdevice drivers, which will be submitted soon.

Changes in v3:

- dropped patches accepted by Paul
- moved IP27 specific __phys_to_dma/__dma_to_phys into its own file
- moved pcibios_to_node into IP27 specific file
- moved PCI bus address resources setup out of pci-xtalk code into
  IP27 specific code
- dropped bit from hub_irq_data and use hwirq from irq_data
- introduced intr_addr for setting up bridge interrupts (IP30 preperation)

Changes in v2:

- replaced HUB_L/HUB_S by __raw_readq/__raw_writeq
- removed union bridge_ate
- replaced remaing fields in slice_data by per_cpu data
- use generic_handle_irq instead of do_IRQ
- use hierarchy irq domain for stacking bridge and hub interrupt
- moved __dma_to_phys/__phy_to_dma to mach-ip27/dma-direct.h
- use dev_to_node() for pcibus_to_node() implementation

Thomas Bogendoerfer (10):
  MIPS: SGI-IP27: get rid of volatile and hubreg_t
  MIPS: SGI-IP27: clean up bridge access and header files
  MIPS: SGI-IP27: use pr_info/pr_emerg and pr_cont to fix output
  MIPS: SGI-IP27: do xtalk scanning later
  MIPS: SGI-IP27: do boot CPU init later
  MIPS: SGI-IP27: rework HUB interrupts
  PCI: call add_bus method also for root bus
  MIPS: SGI-IP27: use generic PCI driver
  genirq/irqdomain: fall back to default domain when creating hierarchy
    domain
  MIPS: SGI-IP27: abstract chipset irq from bridge

 arch/mips/Kconfig                               |   4 +
 arch/mips/include/asm/dma-direct.h              |   2 +
 arch/mips/include/asm/mach-generic/dma-direct.h |   7 +
 arch/mips/include/asm/mach-ip27/dma-direct.h    |  20 +
 arch/mips/include/asm/mach-ip27/irq.h           |  12 +-
 arch/mips/include/asm/mach-ip27/mmzone.h        |   9 -
 arch/mips/include/asm/mach-ip27/topology.h      |  13 +-
 arch/mips/include/asm/pci.h                     |   8 +
 arch/mips/include/asm/pci/bridge.h              | 211 ++++----
 arch/mips/include/asm/smp-ops.h                 |   1 +
 arch/mips/include/asm/sn/addrs.h                |  72 +--
 arch/mips/include/asm/sn/arch.h                 |   2 -
 arch/mips/include/asm/sn/intr.h                 |   6 +
 arch/mips/include/asm/sn/io.h                   |   2 +-
 arch/mips/include/asm/sn/sn0/addrs.h            |   5 -
 arch/mips/include/asm/xtalk/xtalk.h             |   9 -
 arch/mips/kernel/smp.c                          |   2 +
 arch/mips/pci/Makefile                          |   1 -
 arch/mips/pci/ops-bridge.c                      | 322 ------------
 arch/mips/pci/pci-ip27.c                        | 233 ---------
 arch/mips/sgi-ip27/Makefile                     |   3 +-
 arch/mips/sgi-ip27/ip27-hubio.c                 |   4 +-
 arch/mips/sgi-ip27/ip27-init.c                  |  41 +-
 arch/mips/sgi-ip27/ip27-irq-pci.c               | 266 ----------
 arch/mips/sgi-ip27/ip27-irq.c                   | 331 ++++++++-----
 arch/mips/sgi-ip27/ip27-irqno.c                 |  48 --
 arch/mips/sgi-ip27/ip27-memory.c                |  34 +-
 arch/mips/sgi-ip27/ip27-nmi.c                   |  64 +--
 arch/mips/sgi-ip27/ip27-smp.c                   |   5 +-
 arch/mips/sgi-ip27/ip27-timer.c                 |  42 +-
 arch/mips/sgi-ip27/ip27-xtalk.c                 |  44 +-
 drivers/pci/controller/Kconfig                  |   3 +
 drivers/pci/controller/Makefile                 |   1 +
 drivers/pci/controller/pci-xtalk-bridge.c       | 623 ++++++++++++++++++++++++
 drivers/pci/probe.c                             |   6 +
 include/linux/platform_data/xtalk-bridge.h      |  17 +
 kernel/irq/irqdomain.c                          |   5 +-
 37 files changed, 1126 insertions(+), 1352 deletions(-)
 create mode 100644 arch/mips/include/asm/mach-generic/dma-direct.h
 create mode 100644 arch/mips/include/asm/mach-ip27/dma-direct.h
 delete mode 100644 arch/mips/pci/ops-bridge.c
 delete mode 100644 arch/mips/pci/pci-ip27.c
 delete mode 100644 arch/mips/sgi-ip27/ip27-irq-pci.c
 delete mode 100644 arch/mips/sgi-ip27/ip27-irqno.c
 create mode 100644 drivers/pci/controller/pci-xtalk-bridge.c
 create mode 100644 include/linux/platform_data/xtalk-bridge.h

-- 
2.13.7

Re: [PATCH v3 00/3] MIPS: SGI-IP27 rework part2

[Bjorn Helgaas]

Hi Thomas,

On Tue, Mar 19, 2019 at 04:47:49PM +0100, Thomas Bogendoerfer wrote:
> SGI IP27 (Origin/Onyx2) and SGI IP30 (Octane) have a similair
> architecture and share some hardware (ioc3/bridge). To share
> the software parts this patchset reworks SGI IP27 interrupt
> and pci bridge code. By using features Linux gained during the
> many years since SGI IP27 code was integrated this even results
> in code reduction and IMHO cleaner code.
> 
> Tests have been done on a two module O200 (4 CPUs) and an
> Origin 2000 (8 CPUs).

Thanks for doing all this work!  It seems like it basically converts
some of the SGI PCI code to the structure typical of current host
controller drivers and moves it to drivers/pci/controller, which all
seems great to me.

The patches were kind of in limbo as far as Patchwork.  Lorenzo
handles the native host controller drivers, so I just delegated them
to him, so now they should be on his radar.

Bjorn

> My next step in integrating SGI IP30 support is splitting ioc3eth
> into a MFD and subdevice drivers, which will be submitted soon.
> 
> Changes in v3:
> 
> - dropped patches accepted by Paul
> - moved IP27 specific __phys_to_dma/__dma_to_phys into its own file
> - moved pcibios_to_node into IP27 specific file
> - moved PCI bus address resources setup out of pci-xtalk code into
>   IP27 specific code
> - dropped bit from hub_irq_data and use hwirq from irq_data
> - introduced intr_addr for setting up bridge interrupts (IP30 preperation)
> 
> Changes in v2:
> 
> - replaced HUB_L/HUB_S by __raw_readq/__raw_writeq
> - removed union bridge_ate
> - replaced remaing fields in slice_data by per_cpu data
> - use generic_handle_irq instead of do_IRQ
> - use hierarchy irq domain for stacking bridge and hub interrupt
> - moved __dma_to_phys/__phy_to_dma to mach-ip27/dma-direct.h
> - use dev_to_node() for pcibus_to_node() implementation
> 
> Thomas Bogendoerfer (3):
>   MIPS: SGI-IP27: move IP27 specific code out of pci-ip27.c into new
>     file
>   MIPS: SGI-IP27: use generic PCI driver
>   MIPS: SGI-IP27: abstract chipset irq from bridge
> 
>  arch/mips/Kconfig                          |   3 +
>  arch/mips/include/asm/mach-ip27/topology.h |  11 +-
>  arch/mips/include/asm/pci/bridge.h         |  14 +-
>  arch/mips/include/asm/sn/irq_alloc.h       |  11 +
>  arch/mips/include/asm/xtalk/xtalk.h        |   9 -
>  arch/mips/pci/Makefile                     |   1 -
>  arch/mips/pci/ops-bridge.c                 | 302 --------------
>  arch/mips/pci/pci-ip27.c                   | 214 ----------
>  arch/mips/sgi-ip27/Makefile                |   4 +-
>  arch/mips/sgi-ip27/ip27-init.c             |   2 +
>  arch/mips/sgi-ip27/ip27-irq.c              | 191 ++++-----
>  arch/mips/sgi-ip27/ip27-pci.c              |  30 ++
>  arch/mips/sgi-ip27/ip27-xtalk.c            |  61 ++-
>  drivers/pci/controller/Kconfig             |   3 +
>  drivers/pci/controller/Makefile            |   1 +
>  drivers/pci/controller/pci-xtalk-bridge.c  | 610 +++++++++++++++++++++++++++++
>  include/linux/platform_data/xtalk-bridge.h |  22 ++
>  17 files changed, 822 insertions(+), 667 deletions(-)
>  create mode 100644 arch/mips/include/asm/sn/irq_alloc.h
>  delete mode 100644 arch/mips/pci/ops-bridge.c
>  delete mode 100644 arch/mips/pci/pci-ip27.c
>  create mode 100644 arch/mips/sgi-ip27/ip27-pci.c
>  create mode 100644 drivers/pci/controller/pci-xtalk-bridge.c
>  create mode 100644 include/linux/platform_data/xtalk-bridge.h
> 
> -- 
> 2.13.7
> 

Re: [PATCH v3 00/3] MIPS: SGI-IP27 rework part2

[Thomas Bogendoerfer]

On Thu, 18 Apr 2019 15:57:26 -0500
Bjorn Helgaas <helgaas@kernel.org> wrote:

> Hi Thomas,
> 
> On Tue, Mar 19, 2019 at 04:47:49PM +0100, Thomas Bogendoerfer wrote:
> > SGI IP27 (Origin/Onyx2) and SGI IP30 (Octane) have a similair
> > architecture and share some hardware (ioc3/bridge). To share
> > the software parts this patchset reworks SGI IP27 interrupt
> > and pci bridge code. By using features Linux gained during the
> > many years since SGI IP27 code was integrated this even results
> > in code reduction and IMHO cleaner code.
> > 
> > Tests have been done on a two module O200 (4 CPUs) and an
> > Origin 2000 (8 CPUs).
> 
> Thanks for doing all this work!  It seems like it basically converts
> some of the SGI PCI code to the structure typical of current host
> controller drivers and moves it to drivers/pci/controller, which all
> seems great to me.
> 
> The patches were kind of in limbo as far as Patchwork.  Lorenzo
> handles the native host controller drivers, so I just delegated them
> to him, so now they should be on his radar.

Is there a chance to still get this into v5.2 ?

Thomas.

-- 
SUSE Linux GmbH
GF: Felix Imendörffer, Mary Higgins, Sri Rasiah
HRB 21284 (AG Nürnberg)

Re: [PATCH v3 00/3] MIPS: SGI-IP27 rework part2

[Lorenzo Pieralisi]

On Mon, May 06, 2019 at 12:37:24PM +0200, Thomas Bogendoerfer wrote:
> On Thu, 18 Apr 2019 15:57:26 -0500
> Bjorn Helgaas <helgaas@kernel.org> wrote:
> 
> > Hi Thomas,
> > 
> > On Tue, Mar 19, 2019 at 04:47:49PM +0100, Thomas Bogendoerfer wrote:
> > > SGI IP27 (Origin/Onyx2) and SGI IP30 (Octane) have a similair
> > > architecture and share some hardware (ioc3/bridge). To share
> > > the software parts this patchset reworks SGI IP27 interrupt
> > > and pci bridge code. By using features Linux gained during the
> > > many years since SGI IP27 code was integrated this even results
> > > in code reduction and IMHO cleaner code.
> > > 
> > > Tests have been done on a two module O200 (4 CPUs) and an
> > > Origin 2000 (8 CPUs).
> > 
> > Thanks for doing all this work!  It seems like it basically converts
> > some of the SGI PCI code to the structure typical of current host
> > controller drivers and moves it to drivers/pci/controller, which all
> > seems great to me.
> > 
> > The patches were kind of in limbo as far as Patchwork.  Lorenzo
> > handles the native host controller drivers, so I just delegated them
> > to him, so now they should be on his radar.
> 
> Is there a chance to still get this into v5.2 ?

I do not think so, I will have a look as soon as possible, sorry
for the delay.

Lorenzo

Re: [PATCH v3 00/3] MIPS: SGI-IP27 rework part2

[Lorenzo Pieralisi]

On Thu, Apr 18, 2019 at 03:57:26PM -0500, Bjorn Helgaas wrote:
> Hi Thomas,
> 
> On Tue, Mar 19, 2019 at 04:47:49PM +0100, Thomas Bogendoerfer wrote:
> > SGI IP27 (Origin/Onyx2) and SGI IP30 (Octane) have a similair
> > architecture and share some hardware (ioc3/bridge). To share
> > the software parts this patchset reworks SGI IP27 interrupt
> > and pci bridge code. By using features Linux gained during the
> > many years since SGI IP27 code was integrated this even results
> > in code reduction and IMHO cleaner code.
> > 
> > Tests have been done on a two module O200 (4 CPUs) and an
> > Origin 2000 (8 CPUs).
> 
> Thanks for doing all this work!  It seems like it basically converts
> some of the SGI PCI code to the structure typical of current host
> controller drivers and moves it to drivers/pci/controller, which all
> seems great to me.

I had a look and the code is really, really MIPS specific, actually
I would be interested in understanding how many platforms it supports,
it is not even FW configurable.

To give another piece of evidence why some PCI driver code is still in
arch code, look at arch/arm, we did not move it to
drivers/pci/controller for the same reasons, eg lack of DT support.

With hard-coded resources, <asm/...> includes in driver code and MIPS
specific kludges even if it does reuse some APIs shared with controller
drivers I am not 100% certain that moving it to drivers/pci/controller
buys us anything, this is really arch specific code, however we slice
it.

The line between what stays in arch and what goes to
drivers/pci/controller is thin but this code is definitely more on the
arch side IMHO.

I do not question Thomas' effort, which I appreciate, I question
the end result and its usefulness, this series is even increasing
lines of kernel code, I would like to see the benefits.

Lorenzo

> The patches were kind of in limbo as far as Patchwork.  Lorenzo
> handles the native host controller drivers, so I just delegated them
> to him, so now they should be on his radar.
> 
> Bjorn
> 
> > My next step in integrating SGI IP30 support is splitting ioc3eth
> > into a MFD and subdevice drivers, which will be submitted soon.
> > 
> > Changes in v3:
> > 
> > - dropped patches accepted by Paul
> > - moved IP27 specific __phys_to_dma/__dma_to_phys into its own file
> > - moved pcibios_to_node into IP27 specific file
> > - moved PCI bus address resources setup out of pci-xtalk code into
> >   IP27 specific code
> > - dropped bit from hub_irq_data and use hwirq from irq_data
> > - introduced intr_addr for setting up bridge interrupts (IP30 preperation)
> > 
> > Changes in v2:
> > 
> > - replaced HUB_L/HUB_S by __raw_readq/__raw_writeq
> > - removed union bridge_ate
> > - replaced remaing fields in slice_data by per_cpu data
> > - use generic_handle_irq instead of do_IRQ
> > - use hierarchy irq domain for stacking bridge and hub interrupt
> > - moved __dma_to_phys/__phy_to_dma to mach-ip27/dma-direct.h
> > - use dev_to_node() for pcibus_to_node() implementation
> > 
> > Thomas Bogendoerfer (3):
> >   MIPS: SGI-IP27: move IP27 specific code out of pci-ip27.c into new
> >     file
> >   MIPS: SGI-IP27: use generic PCI driver
> >   MIPS: SGI-IP27: abstract chipset irq from bridge
> > 
> >  arch/mips/Kconfig                          |   3 +
> >  arch/mips/include/asm/mach-ip27/topology.h |  11 +-
> >  arch/mips/include/asm/pci/bridge.h         |  14 +-
> >  arch/mips/include/asm/sn/irq_alloc.h       |  11 +
> >  arch/mips/include/asm/xtalk/xtalk.h        |   9 -
> >  arch/mips/pci/Makefile                     |   1 -
> >  arch/mips/pci/ops-bridge.c                 | 302 --------------
> >  arch/mips/pci/pci-ip27.c                   | 214 ----------
> >  arch/mips/sgi-ip27/Makefile                |   4 +-
> >  arch/mips/sgi-ip27/ip27-init.c             |   2 +
> >  arch/mips/sgi-ip27/ip27-irq.c              | 191 ++++-----
> >  arch/mips/sgi-ip27/ip27-pci.c              |  30 ++
> >  arch/mips/sgi-ip27/ip27-xtalk.c            |  61 ++-
> >  drivers/pci/controller/Kconfig             |   3 +
> >  drivers/pci/controller/Makefile            |   1 +
> >  drivers/pci/controller/pci-xtalk-bridge.c  | 610 +++++++++++++++++++++++++++++
> >  include/linux/platform_data/xtalk-bridge.h |  22 ++
> >  17 files changed, 822 insertions(+), 667 deletions(-)
> >  create mode 100644 arch/mips/include/asm/sn/irq_alloc.h
> >  delete mode 100644 arch/mips/pci/ops-bridge.c
> >  delete mode 100644 arch/mips/pci/pci-ip27.c
> >  create mode 100644 arch/mips/sgi-ip27/ip27-pci.c
> >  create mode 100644 drivers/pci/controller/pci-xtalk-bridge.c
> >  create mode 100644 include/linux/platform_data/xtalk-bridge.h
> > 
> > -- 
> > 2.13.7
> > 

Re: [PATCH v3 00/3] MIPS: SGI-IP27 rework part2

[Thomas Bogendoerfer]

On Tue, 7 May 2019 16:31:17 +0100
Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> wrote:

> On Thu, Apr 18, 2019 at 03:57:26PM -0500, Bjorn Helgaas wrote:
> > Hi Thomas,
> > 
> > On Tue, Mar 19, 2019 at 04:47:49PM +0100, Thomas Bogendoerfer wrote:
> > > SGI IP27 (Origin/Onyx2) and SGI IP30 (Octane) have a similair
> > > architecture and share some hardware (ioc3/bridge). To share
> > > the software parts this patchset reworks SGI IP27 interrupt
> > > and pci bridge code. By using features Linux gained during the
> > > many years since SGI IP27 code was integrated this even results
> > > in code reduction and IMHO cleaner code.
> > > 
> > > Tests have been done on a two module O200 (4 CPUs) and an
> > > Origin 2000 (8 CPUs).
> > 
> > Thanks for doing all this work!  It seems like it basically converts
> > some of the SGI PCI code to the structure typical of current host
> > controller drivers and moves it to drivers/pci/controller, which all
> > seems great to me.
> 
> I had a look and the code is really, really MIPS specific, actually
> I would be interested in understanding how many platforms it supports,
> it is not even FW configurable.

it's MIPS only and used in basically 3 different SGI platforms.

> With hard-coded resources, <asm/...> includes in driver code and MIPS
> specific kludges even if it does reuse some APIs shared with controller
> drivers I am not 100% certain that moving it to drivers/pci/controller
> buys us anything, this is really arch specific code, however we slice
> it.

hmm, I thought the idea of having one drivers/pci/controller directory
is to have all of them in one place.

> The line between what stays in arch and what goes to
> drivers/pci/controller is thin but this code is definitely more on the
> arch side IMHO.

what makes the xgene driver different from the xtalk-bridge driver ? Ok
it used DT, but it's still just for a specific type of SOCs from one
vendor, isn't it ?

> I do not question Thomas' effort, which I appreciate, I question
> the end result and its usefulness, this series is even increasing
> lines of kernel code, I would like to see the benefits.

the move from arch/mips/pci to drivers/pci/controller increases lines of
code by two lines. The whole patchset adds 155 lines, but also adds
functionality to be able to use the driver with different platforms.

Anyway I can live with not moving to drivers/pci/controller if you don't
like it there.

Thomas.

-- 
SUSE Linux GmbH
GF: Felix Imendörffer, Mary Higgins, Sri Rasiah
HRB 21284 (AG Nürnberg)

Re: [PATCH v3 00/3] MIPS: SGI-IP27 rework part2

[Lorenzo Pieralisi]

On Tue, May 07, 2019 at 05:48:20PM +0200, Thomas Bogendoerfer wrote:
> On Tue, 7 May 2019 16:31:17 +0100
> Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> wrote:
> 
> > On Thu, Apr 18, 2019 at 03:57:26PM -0500, Bjorn Helgaas wrote:
> > > Hi Thomas,
> > > 
> > > On Tue, Mar 19, 2019 at 04:47:49PM +0100, Thomas Bogendoerfer wrote:
> > > > SGI IP27 (Origin/Onyx2) and SGI IP30 (Octane) have a similair
> > > > architecture and share some hardware (ioc3/bridge). To share
> > > > the software parts this patchset reworks SGI IP27 interrupt
> > > > and pci bridge code. By using features Linux gained during the
> > > > many years since SGI IP27 code was integrated this even results
> > > > in code reduction and IMHO cleaner code.
> > > > 
> > > > Tests have been done on a two module O200 (4 CPUs) and an
> > > > Origin 2000 (8 CPUs).
> > > 
> > > Thanks for doing all this work!  It seems like it basically converts
> > > some of the SGI PCI code to the structure typical of current host
> > > controller drivers and moves it to drivers/pci/controller, which all
> > > seems great to me.
> > 
> > I had a look and the code is really, really MIPS specific, actually
> > I would be interested in understanding how many platforms it supports,
> > it is not even FW configurable.
> 
> it's MIPS only and used in basically 3 different SGI platforms.
> 
> > With hard-coded resources, <asm/...> includes in driver code and MIPS
> > specific kludges even if it does reuse some APIs shared with controller
> > drivers I am not 100% certain that moving it to drivers/pci/controller
> > buys us anything, this is really arch specific code, however we slice
> > it.
> 
> hmm, I thought the idea of having one drivers/pci/controller directory
> is to have all of them in one place.

Well, drivers/pci/controller code should at least try to be arch
agnostic to belong there, there are exceptions, as I said but
they are the exception not the rule.

> > The line between what stays in arch and what goes to
> > drivers/pci/controller is thin but this code is definitely more on the
> > arch side IMHO.
> 
> what makes the xgene driver different from the xtalk-bridge driver ? Ok
> it used DT, but it's still just for a specific type of SOCs from one
> vendor, isn't it ?

Eg no <asm/...> includes required; its code can in principle be
reused on other arches, this series can't, it is arch code IMO.

> > I do not question Thomas' effort, which I appreciate, I question
> > the end result and its usefulness, this series is even increasing
> > lines of kernel code, I would like to see the benefits.
> 
> the move from arch/mips/pci to drivers/pci/controller increases lines of
> code by two lines. The whole patchset adds 155 lines, but also adds
> functionality to be able to use the driver with different platforms.

I am not convinced it will buy you much to be honest, I might be wrong.

If we move the code we have to have a compelling reason for it to
happen and at the moment I do not necessarily see one, happy to
be proven wrong if you extend it to support other platforms cleanly
(eg with firmware bindings) on top of this series.

> Anyway I can live with not moving to drivers/pci/controller if you don't
> like it there.

I can't certainly maintain it, it is too MIPS specific and I do not like
this code either but that's certainly not your fault.

- Hardcoded resources
- No firmware bindings
- Lots of MIPS specific workarounds
- arch code dependency

I do not think that as it stands it belongs in driver/pci/controller,
no.

Thanks,
Lorenzo

Re: [PATCH v3 00/3] MIPS: SGI-IP27 rework part2

[Christoph Hellwig]

On Tue, May 07, 2019 at 05:48:20PM +0200, Thomas Bogendoerfer wrote:
> > I had a look and the code is really, really MIPS specific, actually
> > I would be interested in understanding how many platforms it supports,
> > it is not even FW configurable.
> 
> it's MIPS only and used in basically 3 different SGI platforms.

Actually this isn't quite true, this whole infraѕtructure was also
shared by the SGI IA64 systems.

The early SN1 prototypes were basically just IP35 systems with IA64
CPUs glued in, and even the later SN2 that were released as Altix
shared the same xtalk + bridge infrastructure, just with some hardware
updates.  It just turned out SGI at some point decided to hide all that
in firmware.  Linux 2.4 was still accessing this natively, but the code
was a mess.  I tried to consolidate it with the mips version at that
point, but SGI decided that hiding it under firmware calls was easier
as they could just move the messy code there.

So, not it isn't really MIPS only in theory, although in practice it
very much is..