10 files changed, 985 insertions, 0 deletions

diff --git a/arch/tile/Kconfig b/arch/tile/Kconfig
index fe128816c448..645979cfb718 100644
--- a/arch/tile/Kconfig
+++ b/arch/tile/Kconfig
@@ -345,6 +345,8 @@ config KERNEL_PL
           kernel will be built to run at.  Generally you should use
           the default value here.
 
+source "arch/tile/gxio/Kconfig"
+
 endmenu  # Tilera-specific configuration
 
 menu "Bus options"
diff --git a/arch/tile/Makefile b/arch/tile/Makefile
index e20b0a0b64a1..55640cf92597 100644
--- a/arch/tile/Makefile
+++ b/arch/tile/Makefile
@@ -59,6 +59,8 @@ libs-y		+= $(LIBGCC_PATH)
 # See arch/tile/Kbuild for content of core part of the kernel
 core-y          += arch/tile/
 
+core-$(CONFIG_TILE_GXIO) += arch/tile/gxio/
+
 ifdef TILERA_ROOT
 INSTALL_PATH ?= $(TILERA_ROOT)/tile/boot
 endif
diff --git a/arch/tile/gxio/Kconfig b/arch/tile/gxio/Kconfig
new file mode 100644
index 000000000000..8eff47fe1236
--- /dev/null
+++ b/arch/tile/gxio/Kconfig
@@ -0,0 +1,5 @@
+# Support direct access to TILE-Gx hardware from user space, via the
+# gxio library, or from kernel space, via kernel IORPC support.
+config TILE_GXIO
+        bool
+        depends on TILEGX
diff --git a/arch/tile/gxio/Makefile b/arch/tile/gxio/Makefile
new file mode 100644
index 000000000000..db1ee2863d8e
--- /dev/null
+++ b/arch/tile/gxio/Makefile
@@ -0,0 +1,5 @@
+#
+# Makefile for the Tile-Gx device access support.
+#
+
+obj-$(CONFIG_TILE_GXIO) += iorpc_globals.o kiorpc.o
diff --git a/arch/tile/gxio/iorpc_globals.c b/arch/tile/gxio/iorpc_globals.c
new file mode 100644
index 000000000000..e178e90805a2
--- /dev/null
+++ b/arch/tile/gxio/iorpc_globals.c
@@ -0,0 +1,89 @@
+/*
+ * Copyright 2012 Tilera Corporation. All Rights Reserved.
+ *
+ *   This program is free software; you can redistribute it and/or
+ *   modify it under the terms of the GNU General Public License
+ *   as published by the Free Software Foundation, version 2.
+ *
+ *   This program is distributed in the hope that it will be useful, but
+ *   WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ *   NON INFRINGEMENT.  See the GNU General Public License for
+ *   more details.
+ */
+
+/* This file is machine-generated; DO NOT EDIT! */
+#include "gxio/iorpc_globals.h"
+
+struct arm_pollfd_param {
+        union iorpc_pollfd pollfd;
+};
+
+int __iorpc_arm_pollfd(int fd, int pollfd_cookie)
+{
+        struct arm_pollfd_param temp;
+        struct arm_pollfd_param *params = &temp;
+
+        params->pollfd.kernel.cookie = pollfd_cookie;
+
+        return hv_dev_pwrite(fd, 0, (HV_VirtAddr) params, sizeof(*params),
+                             IORPC_OP_ARM_POLLFD);
+}
+
+EXPORT_SYMBOL(__iorpc_arm_pollfd);
+
+struct close_pollfd_param {
+        union iorpc_pollfd pollfd;
+};
+
+int __iorpc_close_pollfd(int fd, int pollfd_cookie)
+{
+        struct close_pollfd_param temp;
+        struct close_pollfd_param *params = &temp;
+
+        params->pollfd.kernel.cookie = pollfd_cookie;
+
+        return hv_dev_pwrite(fd, 0, (HV_VirtAddr) params, sizeof(*params),
+                             IORPC_OP_CLOSE_POLLFD);
+}
+
+EXPORT_SYMBOL(__iorpc_close_pollfd);
+
+struct get_mmio_base_param {
+        HV_PTE base;
+};
+
+int __iorpc_get_mmio_base(int fd, HV_PTE *base)
+{
+        int __result;
+        struct get_mmio_base_param temp;
+        struct get_mmio_base_param *params = &temp;
+
+        __result =
+            hv_dev_pread(fd, 0, (HV_VirtAddr) params, sizeof(*params),
+                         IORPC_OP_GET_MMIO_BASE);
+        *base = params->base;
+
+        return __result;
+}
+
+EXPORT_SYMBOL(__iorpc_get_mmio_base);
+
+struct check_mmio_offset_param {
+        unsigned long offset;
+        unsigned long size;
+};
+
+int __iorpc_check_mmio_offset(int fd, unsigned long offset, unsigned long size)
+{
+        struct check_mmio_offset_param temp;
+        struct check_mmio_offset_param *params = &temp;
+
+        params->offset = offset;
+        params->size = size;
+
+        return hv_dev_pwrite(fd, 0, (HV_VirtAddr) params, sizeof(*params),
+                             IORPC_OP_CHECK_MMIO_OFFSET);
+}
+
+EXPORT_SYMBOL(__iorpc_check_mmio_offset);
diff --git a/arch/tile/gxio/kiorpc.c b/arch/tile/gxio/kiorpc.c
new file mode 100644
index 000000000000..c8096aa5a3fc
--- /dev/null
+++ b/arch/tile/gxio/kiorpc.c
@@ -0,0 +1,61 @@
+/*
+ * Copyright 2012 Tilera Corporation. All Rights Reserved.
+ *
+ *   This program is free software; you can redistribute it and/or
+ *   modify it under the terms of the GNU General Public License
+ *   as published by the Free Software Foundation, version 2.
+ *
+ *   This program is distributed in the hope that it will be useful, but
+ *   WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ *   NON INFRINGEMENT.  See the GNU General Public License for
+ *   more details.
+ *
+ * TILE-Gx IORPC support for kernel I/O drivers.
+ */
+
+#include <linux/mmzone.h>
+#include <linux/module.h>
+#include <linux/io.h>
+#include <gxio/iorpc_globals.h>
+#include <gxio/kiorpc.h>
+
+#ifdef DEBUG_IORPC
+#define TRACE(FMT, ...) pr_info(SIMPLE_MSG_LINE FMT, ## __VA_ARGS__)
+#else
+#define TRACE(...)
+#endif
+
+/* Create kernel-VA-space MMIO mapping for an on-chip IO device. */
+void __iomem *iorpc_ioremap(int hv_fd, resource_size_t offset,
+                            unsigned long size)
+{
+        pgprot_t mmio_base, prot = { 0 };
+        unsigned long pfn;
+        int err;
+
+        /* Look up the shim's lotar and base PA. */
+        err = __iorpc_get_mmio_base(hv_fd, &mmio_base);
+        if (err) {
+                TRACE("get_mmio_base() failure: %d\n", err);
+                return NULL;
+        }
+
+        /* Make sure the HV driver approves of our offset and size. */
+        err = __iorpc_check_mmio_offset(hv_fd, offset, size);
+        if (err) {
+                TRACE("check_mmio_offset() failure: %d\n", err);
+                return NULL;
+        }
+
+        /*
+         * mmio_base contains a base pfn and homing coordinates.  Turn
+         * it into an MMIO pgprot and offset pfn.
+         */
+        prot = hv_pte_set_lotar(prot, hv_pte_get_lotar(mmio_base));
+        pfn = pte_pfn(mmio_base) + PFN_DOWN(offset);
+
+        return ioremap_prot(PFN_PHYS(pfn), size, prot);
+}
+
+EXPORT_SYMBOL(iorpc_ioremap);
diff --git a/arch/tile/include/gxio/common.h b/arch/tile/include/gxio/common.h
new file mode 100644
index 000000000000..724595a24d04
--- /dev/null
+++ b/arch/tile/include/gxio/common.h
@@ -0,0 +1,40 @@
+/*
+ * Copyright 2012 Tilera Corporation. All Rights Reserved.
+ *
+ *   This program is free software; you can redistribute it and/or
+ *   modify it under the terms of the GNU General Public License
+ *   as published by the Free Software Foundation, version 2.
+ *
+ *   This program is distributed in the hope that it will be useful, but
+ *   WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ *   NON INFRINGEMENT.  See the GNU General Public License for
+ *   more details.
+ */
+
+#ifndef _GXIO_COMMON_H_
+#define _GXIO_COMMON_H_
+
+/*
+ * Routines shared between the various GXIO device components.
+ */
+
+#include <hv/iorpc.h>
+
+#include <linux/types.h>
+#include <linux/compiler.h>
+#include <linux/io.h>
+
+/* Define the standard gxio MMIO functions using kernel functions. */
+#define __gxio_mmio_read8(addr)         readb(addr)
+#define __gxio_mmio_read16(addr)        readw(addr)
+#define __gxio_mmio_read32(addr)        readl(addr)
+#define __gxio_mmio_read64(addr)        readq(addr)
+#define __gxio_mmio_write8(addr, val)   writeb((val), (addr))
+#define __gxio_mmio_write16(addr, val)  writew((val), (addr))
+#define __gxio_mmio_write32(addr, val)  writel((val), (addr))
+#define __gxio_mmio_write64(addr, val)  writeq((val), (addr))
+#define __gxio_mmio_read(addr)          __gxio_mmio_read64(addr)
+#define __gxio_mmio_write(addr, val)    __gxio_mmio_write64((addr), (val))
+
+#endif /* !_GXIO_COMMON_H_ */
diff --git a/arch/tile/include/gxio/iorpc_globals.h b/arch/tile/include/gxio/iorpc_globals.h
new file mode 100644
index 000000000000..52c721f8dad9
--- /dev/null
+++ b/arch/tile/include/gxio/iorpc_globals.h
@@ -0,0 +1,38 @@
+/*
+ * Copyright 2012 Tilera Corporation. All Rights Reserved.
+ *
+ *   This program is free software; you can redistribute it and/or
+ *   modify it under the terms of the GNU General Public License
+ *   as published by the Free Software Foundation, version 2.
+ *
+ *   This program is distributed in the hope that it will be useful, but
+ *   WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ *   NON INFRINGEMENT.  See the GNU General Public License for
+ *   more details.
+ */
+
+/* This file is machine-generated; DO NOT EDIT! */
+#ifndef __IORPC_LINUX_RPC_H__
+#define __IORPC_LINUX_RPC_H__
+
+#include <hv/iorpc.h>
+
+#include <linux/string.h>
+#include <linux/module.h>
+#include <asm/pgtable.h>
+
+#define IORPC_OP_ARM_POLLFD            IORPC_OPCODE(IORPC_FORMAT_KERNEL_POLLFD, 0x9000)
+#define IORPC_OP_CLOSE_POLLFD          IORPC_OPCODE(IORPC_FORMAT_KERNEL_POLLFD, 0x9001)
+#define IORPC_OP_GET_MMIO_BASE         IORPC_OPCODE(IORPC_FORMAT_NONE_NOUSER, 0x8000)
+#define IORPC_OP_CHECK_MMIO_OFFSET     IORPC_OPCODE(IORPC_FORMAT_NONE_NOUSER, 0x8001)
+
+int __iorpc_arm_pollfd(int fd, int pollfd_cookie);
+
+int __iorpc_close_pollfd(int fd, int pollfd_cookie);
+
+int __iorpc_get_mmio_base(int fd, HV_PTE *base);
+
+int __iorpc_check_mmio_offset(int fd, unsigned long offset, unsigned long size);
+
+#endif /* !__IORPC_LINUX_RPC_H__ */
diff --git a/arch/tile/include/gxio/kiorpc.h b/arch/tile/include/gxio/kiorpc.h
new file mode 100644
index 000000000000..ee5820979ff3
--- /dev/null
+++ b/arch/tile/include/gxio/kiorpc.h
@@ -0,0 +1,29 @@
+/*
+ * Copyright 2012 Tilera Corporation. All Rights Reserved.
+ *
+ *   This program is free software; you can redistribute it and/or
+ *   modify it under the terms of the GNU General Public License
+ *   as published by the Free Software Foundation, version 2.
+ *
+ *   This program is distributed in the hope that it will be useful, but
+ *   WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ *   NON INFRINGEMENT.  See the GNU General Public License for
+ *   more details.
+ *
+ * Support routines for kernel IORPC drivers.
+ */
+
+#ifndef _GXIO_KIORPC_H
+#define _GXIO_KIORPC_H
+
+#include <linux/types.h>
+#include <asm/page.h>
+#include <arch/chip.h>
+
+#if CHIP_HAS_MMIO()
+void __iomem *iorpc_ioremap(int hv_fd, resource_size_t offset,
+                            unsigned long size);
+#endif
+
+#endif /* _GXIO_KIORPC_H */
diff --git a/arch/tile/include/hv/iorpc.h b/arch/tile/include/hv/iorpc.h
new file mode 100644
index 000000000000..89c72a5d9341
--- /dev/null
+++ b/arch/tile/include/hv/iorpc.h
@@ -0,0 +1,714 @@
+/*
+ * Copyright 2012 Tilera Corporation. All Rights Reserved.
+ *
+ *   This program is free software; you can redistribute it and/or
+ *   modify it under the terms of the GNU General Public License
+ *   as published by the Free Software Foundation, version 2.
+ *
+ *   This program is distributed in the hope that it will be useful, but
+ *   WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ *   NON INFRINGEMENT.  See the GNU General Public License for
+ *   more details.
+ */
+#ifndef _HV_IORPC_H_
+#define _HV_IORPC_H_
+
+/**
+ *
+ * Error codes and struct definitions for the IO RPC library.
+ *
+ * The hypervisor's IO RPC component provides a convenient way for
+ * driver authors to proxy system calls between user space, linux, and
+ * the hypervisor driver.  The core of the system is a set of Python
+ * files that take ".idl" files as input and generates the following
+ * source code:
+ *
+ * - _rpc_call() routines for use in userspace IO libraries.  These
+ * routines take an argument list specified in the .idl file, pack the
+ * arguments in to a buffer, and read or write that buffer via the
+ * Linux iorpc driver.
+ *
+ * - dispatch_read() and dispatch_write() routines that hypervisor
+ * drivers can use to implement most of their dev_pread() and
+ * dev_pwrite() methods.  These routines decode the incoming parameter
+ * blob, permission check and translate parameters where appropriate,
+ * and then invoke a callback routine for whichever RPC call has
+ * arrived.  The driver simply implements the set of callback
+ * routines.
+ *
+ * The IO RPC system also includes the Linux 'iorpc' driver, which
+ * proxies calls between the userspace library and the hypervisor
+ * driver.  The Linux driver is almost entirely device agnostic; it
+ * watches for special flags indicating cases where a memory buffer
+ * address might need to be translated, etc.  As a result, driver
+ * writers can avoid many of the problem cases related to registering
+ * hardware resources like memory pages or interrupts.  However, the
+ * drivers must be careful to obey the conventions documented below in
+ * order to work properly with the generic Linux iorpc driver.
+ *
+ * @section iorpc_domains Service Domains
+ *
+ * All iorpc-based drivers must support a notion of service domains.
+ * A service domain is basically an application context - state
+ * indicating resources that are allocated to that particular app
+ * which it may access and (perhaps) other applications may not
+ * access.  Drivers can support any number of service domains they
+ * choose.  In some cases the design is limited by a number of service
+ * domains supported by the IO hardware; in other cases the service
+ * domains are a purely software concept and the driver chooses a
+ * maximum number of domains based on how much state memory it is
+ * willing to preallocate.
+ *
+ * For example, the mPIPE driver only supports as many service domains
+ * as are supported by the mPIPE hardware.  This limitation is
+ * required because the hardware implements its own MMIO protection
+ * scheme to allow large MMIO mappings while still protecting small
+ * register ranges within the page that should only be accessed by the
+ * hypervisor.
+ *
+ * In contrast, drivers with no hardware service domain limitations
+ * (for instance the TRIO shim) can implement an arbitrary number of
+ * service domains.  In these cases, each service domain is limited to
+ * a carefully restricted set of legal MMIO addresses if necessary to
+ * keep one application from corrupting another application's state.
+ *
+ * @section iorpc_conventions System Call Conventions
+ *
+ * The driver's open routine is responsible for allocating a new
+ * service domain for each hv_dev_open() call.  By convention, the
+ * return value from open() should be the service domain number on
+ * success, or GXIO_ERR_NO_SVC_DOM if no more service domains are
+ * available.
+ *
+ * The implementations of hv_dev_pread() and hv_dev_pwrite() are
+ * responsible for validating the devhdl value passed up by the
+ * client.  Since the device handle returned by hv_dev_open() should
+ * embed the positive service domain number, drivers should make sure
+ * that DRV_HDL2BITS(devhdl) is a legal service domain.  If the client
+ * passes an illegal service domain number, the routine should return
+ * GXIO_ERR_INVAL_SVC_DOM.  Once the service domain number has been
+ * validated, the driver can copy to/from the client buffer and call
+ * the dispatch_read() or dispatch_write() methods created by the RPC
+ * generator.
+ *
+ * The hv_dev_close() implementation should reset all service domain
+ * state and put the service domain back on a free list for
+ * reallocation by a future application.  In most cases, this will
+ * require executing a hardware reset or drain flow and denying any
+ * MMIO regions that were created for the service domain.
+ *
+ * @section iorpc_data Special Data Types
+ *
+ * The .idl file syntax allows the creation of syscalls with special
+ * parameters that require permission checks or translations as part
+ * of the system call path.  Because of limitations in the code
+ * generator, APIs are generally limited to just one of these special
+ * parameters per system call, and they are sometimes required to be
+ * the first or last parameter to the call.  Special parameters
+ * include:
+ *
+ * @subsection iorpc_mem_buffer MEM_BUFFER
+ *
+ * The MEM_BUFFER() datatype allows user space to "register" memory
+ * buffers with a device.  Registering memory accomplishes two tasks:
+ * Linux keeps track of all buffers that might be modified by a
+ * hardware device, and the hardware device drivers bind registered
+ * buffers to particular hardware resources like ingress NotifRings.
+ * The MEM_BUFFER() idl syntax can take extra flags like ALIGN_64KB,
+ * ALIGN_SELF_SIZE, and FLAGS indicating that memory buffers must have
+ * certain alignment or that the user should be able to pass a "memory
+ * flags" word specifying attributes like nt_hint or IO cache pinning.
+ * The parser will accept multiple MEM_BUFFER() flags.
+ *
+ * Implementations must obey the following conventions when
+ * registering memory buffers via the iorpc flow.  These rules are a
+ * result of the Linux driver implementation, which needs to keep
+ * track of how many times a particular page has been registered with
+ * the hardware so that it can release the page when all those
+ * registrations are cleared.
+ *
+ * - Memory registrations that refer to a resource which has already
+ * been bound must return GXIO_ERR_ALREADY_INIT.  Thus, it is an
+ * error to register memory twice without resetting (i.e. closing) the
+ * resource in between.  This convention keeps the Linux driver from
+ * having to track which particular devices a page is bound to.
+ *
+ * - At present, a memory registration is only cleared when the
+ * service domain is reset.  In this case, the Linux driver simply
+ * closes the HV device file handle and then decrements the reference
+ * counts of all pages that were previously registered with the
+ * device.
+ *
+ * - In the future, we may add a mechanism for unregistering memory.
+ * One possible implementation would require that the user specify
+ * which buffer is currently registered.  The HV would then verify
+ * that that page was actually the one currently mapped and return
+ * success or failure to Linux, which would then only decrement the
+ * page reference count if the addresses were mapped.  Another scheme
+ * might allow Linux to pass a token to the HV to be returned when the
+ * resource is unmapped.
+ *
+ * @subsection iorpc_interrupt INTERRUPT
+ *
+ * The INTERRUPT .idl datatype allows the client to bind hardware
+ * interrupts to a particular combination of IPI parameters - CPU, IPI
+ * PL, and event bit number.  This data is passed via a special
+ * datatype so that the Linux driver can validate the CPU and PL and
+ * the HV generic iorpc code can translate client CPUs to real CPUs.
+ *
+ * @subsection iorpc_pollfd_setup POLLFD_SETUP
+ *
+ * The POLLFD_SETUP .idl datatype allows the client to set up hardware
+ * interrupt bindings which are received by Linux but which are made
+ * visible to user processes as state transitions on a file descriptor;
+ * this allows user processes to use Linux primitives, such as poll(), to
+ * await particular hardware events.  This data is passed via a special
+ * datatype so that the Linux driver may recognize the pollable file
+ * descriptor and translate it to a set of interrupt target information,
+ * and so that the HV generic iorpc code can translate client CPUs to real
+ * CPUs.
+ *
+ * @subsection iorpc_pollfd POLLFD
+ *
+ * The POLLFD .idl datatype allows manipulation of hardware interrupt
+ * bindings set up via the POLLFD_SETUP datatype; common operations are
+ * resetting the state of the requested interrupt events, and unbinding any
+ * bound interrupts.  This data is passed via a special datatype so that
+ * the Linux driver may recognize the pollable file descriptor and
+ * translate it to an interrupt identifier previously supplied by the
+ * hypervisor as the result of an earlier pollfd_setup operation.
+ *
+ * @subsection iorpc_blob BLOB
+ *
+ * The BLOB .idl datatype allows the client to write an arbitrary
+ * length string of bytes up to the hypervisor driver.  This can be
+ * useful for passing up large, arbitrarily structured data like
+ * classifier programs.  The iorpc stack takes care of validating the
+ * buffer VA and CPA as the data passes up to the hypervisor.  Unlike
+ * MEM_BUFFER(), the buffer is not registered - Linux does not bump
+ * page refcounts and the HV driver should not reuse the buffer once
+ * the system call is complete.
+ *
+ * @section iorpc_translation Translating User Space Calls
+ *
+ * The ::iorpc_offset structure describes the formatting of the offset
+ * that is passed to pread() or pwrite() as part of the generated RPC code.
+ * When the user calls up to Linux, the rpc code fills in all the fields of
+ * the offset, including a 16-bit opcode, a 16 bit format indicator, and 32
+ * bits of user-specified "sub-offset".  The opcode indicates which syscall
+ * is being requested.  The format indicates whether there is a "prefix
+ * struct" at the start of the memory buffer passed to pwrite(), and if so
+ * what data is in that prefix struct.  These prefix structs are used to
+ * implement special datatypes like MEM_BUFFER() and INTERRUPT - we arrange
+ * to put data that needs translation and permission checks at the start of
+ * the buffer so that the Linux driver and generic portions of the HV iorpc
+ * code can easily access the data.  The 32 bits of user-specified
+ * "sub-offset" are most useful for pread() calls where the user needs to
+ * also pass in a few bits indicating which register to read, etc.
+ *
+ * The Linux iorpc driver watches for system calls that contain prefix
+ * structs so that it can translate parameters and bump reference
+ * counts as appropriate.  It does not (currently) have any knowledge
+ * of the per-device opcodes - it doesn't care what operation you're
+ * doing to mPIPE, so long as it can do all the generic book-keeping.
+ * The hv/iorpc.h header file defines all of the generic encoding bits
+ * needed to translate iorpc calls without knowing which particular
+ * opcode is being issued.
+ *
+ * @section iorpc_globals Global iorpc Calls
+ *
+ * Implementing mmap() required adding some special iorpc syscalls
+ * that are only called by the Linux driver, never by userspace.
+ * These include get_mmio_base() and check_mmio_offset().  These
+ * routines are described in globals.idl and must be included in every
+ * iorpc driver.  By providing these routines in every driver, Linux's
+ * mmap implementation can easily get the PTE bits it needs and
+ * validate the PA offset without needing to know the per-device
+ * opcodes to perform those tasks.
+ *
+ * @section iorpc_kernel Supporting gxio APIs in the Kernel
+ *
+ * The iorpc code generator also supports generation of kernel code
+ * implementing the gxio APIs.  This capability is currently used by
+ * the mPIPE network driver, and will likely be used by the TRIO root
+ * complex and endpoint drivers and perhaps an in-kernel crypto
+ * driver.  Each driver that wants to instantiate iorpc calls in the
+ * kernel needs to generate a kernel version of the generate rpc code
+ * and (probably) copy any related gxio source files into the kernel.
+ * The mPIPE driver provides a good example of this pattern.
+ */
+
+#ifdef __KERNEL__
+#include <linux/stddef.h>
+#else
+#include <stddef.h>
+#endif
+
+#if defined(__HV__)
+#include <hv/hypervisor.h>
+#elif defined(__KERNEL__)
+#include "hypervisor.h"
+#include <linux/types.h>
+#else
+#include <stdint.h>
+#endif
+
+
+/** Code indicating translation services required within the RPC path.
+ * These indicate whether there is a translatable struct at the start
+ * of the RPC buffer and what information that struct contains.
+ */
+enum iorpc_format_e
+{
+  /** No translation required, no prefix struct. */
+  IORPC_FORMAT_NONE,
+
+  /** No translation required, no prefix struct, no access to this
+   *  operation from user space. */
+  IORPC_FORMAT_NONE_NOUSER,
+
+  /** Prefix struct contains user VA and size. */
+  IORPC_FORMAT_USER_MEM,
+
+  /** Prefix struct contains CPA, size, and homing bits. */
+  IORPC_FORMAT_KERNEL_MEM,
+
+  /** Prefix struct contains interrupt. */
+  IORPC_FORMAT_KERNEL_INTERRUPT,
+
+  /** Prefix struct contains user-level interrupt. */
+  IORPC_FORMAT_USER_INTERRUPT,
+
+  /** Prefix struct contains pollfd_setup (interrupt information). */
+  IORPC_FORMAT_KERNEL_POLLFD_SETUP,
+
+  /** Prefix struct contains user-level pollfd_setup (file descriptor). */
+  IORPC_FORMAT_USER_POLLFD_SETUP,
+
+  /** Prefix struct contains pollfd (interrupt cookie). */
+  IORPC_FORMAT_KERNEL_POLLFD,
+
+  /** Prefix struct contains user-level pollfd (file descriptor). */
+  IORPC_FORMAT_USER_POLLFD,
+};
+
+
+/** Generate an opcode given format and code. */
+#define IORPC_OPCODE(FORMAT, CODE) (((FORMAT) << 16) | (CODE))
+
+/** The offset passed through the read() and write() system calls
+    combines an opcode with 32 bits of user-specified offset. */
+union iorpc_offset
+{
+#ifndef __BIG_ENDIAN__
+  uint64_t offset;              /**< All bits. */
+
+  struct
+  {
+    uint16_t code;              /**< RPC code. */
+    uint16_t format;            /**< iorpc_format_e */
+    uint32_t sub_offset;        /**< caller-specified offset. */
+  };
+
+  uint32_t opcode;              /**< Opcode combines code & format. */
+#else
+  uint64_t offset;              /**< All bits. */
+
+  struct
+  {
+    uint32_t sub_offset;        /**< caller-specified offset. */
+    uint16_t format;            /**< iorpc_format_e */
+    uint16_t code;              /**< RPC code. */
+  };
+
+  struct
+  {
+    uint32_t padding;
+    uint32_t opcode;              /**< Opcode combines code & format. */
+  };
+#endif
+};
+
+
+/** Homing and cache hinting bits that can be used by IO devices. */
+struct iorpc_mem_attr
+{
+  unsigned int lotar_x:4;       /**< lotar X bits (or Gx page_mask). */
+  unsigned int lotar_y:4;       /**< lotar Y bits (or Gx page_offset). */
+  unsigned int hfh:1;           /**< Uses hash-for-home. */
+  unsigned int nt_hint:1;       /**< Non-temporal hint. */
+  unsigned int io_pin:1;        /**< Only fill 'IO' cache ways. */
+};
+
+/** Set the nt_hint bit. */
+#define IORPC_MEM_BUFFER_FLAG_NT_HINT (1 << 0)
+
+/** Set the IO pin bit. */
+#define IORPC_MEM_BUFFER_FLAG_IO_PIN (1 << 1)
+
+
+/** A structure used to describe memory registration.  Different
+    protection levels describe memory differently, so this union
+    contains all the different possible descriptions.  As a request
+    moves up the call chain, each layer translates from one
+    description format to the next.  In particular, the Linux iorpc
+    driver translates user VAs into CPAs and homing parameters. */
+union iorpc_mem_buffer
+{
+  struct
+  {
+    uint64_t va;                /**< User virtual address. */
+    uint64_t size;              /**< Buffer size. */
+    unsigned int flags;         /**< nt_hint, IO pin. */
+  }
+  user;                         /**< Buffer as described by user apps. */
+
+  struct
+  {
+    unsigned long long cpa;     /**< Client physical address. */
+#if defined(__KERNEL__) || defined(__HV__)
+    size_t size;                /**< Buffer size. */
+    HV_PTE pte;                 /**< PTE describing memory homing. */
+#else
+    uint64_t size;
+    uint64_t pte;
+#endif
+    unsigned int flags;         /**< nt_hint, IO pin. */
+  }
+  kernel;                       /**< Buffer as described by kernel. */
+
+  struct
+  {
+    unsigned long long pa;      /**< Physical address. */
+    size_t size;                /**< Buffer size. */
+    struct iorpc_mem_attr attr;      /**< Homing and locality hint bits. */
+  }
+  hv;                           /**< Buffer parameters for HV driver. */
+};
+
+
+/** A structure used to describe interrupts.  The format differs slightly
+ *  for user and kernel interrupts.  As with the mem_buffer_t, translation
+ *  between the formats is done at each level. */
+union iorpc_interrupt
+{
+  struct
+  {
+    int cpu;   /**< CPU. */
+    int event; /**< evt_num */
+  }
+  user;        /**< Interrupt as described by user applications. */
+
+  struct
+  {
+    int x;     /**< X coord. */
+    int y;     /**< Y coord. */
+    int ipi;   /**< int_num */
+    int event; /**< evt_num */
+  }
+  kernel;      /**< Interrupt as described by the kernel. */
+
+};
+
+
+/** A structure used to describe interrupts used with poll().  The format
+ *  differs significantly for requests from user to kernel, and kernel to
+ *  hypervisor.  As with the mem_buffer_t, translation between the formats
+ *  is done at each level. */
+union iorpc_pollfd_setup
+{
+  struct
+  {
+    int fd;    /**< Pollable file descriptor. */
+  }
+  user;        /**< pollfd_setup as described by user applications. */
+
+  struct
+  {
+    int x;     /**< X coord. */
+    int y;     /**< Y coord. */
+    int ipi;   /**< int_num */
+    int event; /**< evt_num */
+  }
+  kernel;      /**< pollfd_setup as described by the kernel. */
+
+};
+
+
+/** A structure used to describe previously set up interrupts used with
+ *  poll().  The format differs significantly for requests from user to
+ *  kernel, and kernel to hypervisor.  As with the mem_buffer_t, translation
+ *  between the formats is done at each level. */
+union iorpc_pollfd
+{
+  struct
+  {
+    int fd;    /**< Pollable file descriptor. */
+  }
+  user;        /**< pollfd as described by user applications. */
+
+  struct
+  {
+    int cookie; /**< hv cookie returned by the pollfd_setup operation. */
+  }
+  kernel;      /**< pollfd as described by the kernel. */
+
+};
+
+
+/** The various iorpc devices use error codes from -1100 to -1299.
+ *
+ * This range is distinct from netio (-700 to -799), the hypervisor
+ * (-800 to -899), tilepci (-900 to -999), ilib (-1000 to -1099),
+ * gxcr (-1300 to -1399) and gxpci (-1400 to -1499).
+ */
+enum gxio_err_e {
+
+  /** Largest iorpc error number. */
+  GXIO_ERR_MAX = -1101,
+
+
+  /********************************************************/
+  /*                   Generic Error Codes                */
+  /********************************************************/
+
+  /** Bad RPC opcode - possible version incompatibility. */
+  GXIO_ERR_OPCODE = -1101,
+
+  /** Invalid parameter. */
+  GXIO_ERR_INVAL = -1102,
+
+  /** Memory buffer did not meet alignment requirements. */
+  GXIO_ERR_ALIGNMENT = -1103,
+
+  /** Memory buffers must be coherent and cacheable. */
+  GXIO_ERR_COHERENCE = -1104,
+
+  /** Resource already initialized. */
+  GXIO_ERR_ALREADY_INIT = -1105,
+
+  /** No service domains available. */
+  GXIO_ERR_NO_SVC_DOM = -1106,
+
+  /** Illegal service domain number. */
+  GXIO_ERR_INVAL_SVC_DOM = -1107,
+
+  /** Illegal MMIO address. */
+  GXIO_ERR_MMIO_ADDRESS = -1108,
+
+  /** Illegal interrupt binding. */
+  GXIO_ERR_INTERRUPT = -1109,
+
+  /** Unreasonable client memory. */
+  GXIO_ERR_CLIENT_MEMORY = -1110,
+
+  /** No more IOTLB entries. */
+  GXIO_ERR_IOTLB_ENTRY = -1111,
+
+  /** Invalid memory size. */
+  GXIO_ERR_INVAL_MEMORY_SIZE = -1112,
+
+  /** Unsupported operation. */
+  GXIO_ERR_UNSUPPORTED_OP = -1113,
+
+  /** Insufficient DMA credits. */
+  GXIO_ERR_DMA_CREDITS = -1114,
+
+  /** Operation timed out. */
+  GXIO_ERR_TIMEOUT = -1115,
+
+  /** No such device or object. */
+  GXIO_ERR_NO_DEVICE = -1116,
+
+  /** Device or resource busy. */
+  GXIO_ERR_BUSY = -1117,
+
+  /** I/O error. */
+  GXIO_ERR_IO = -1118,
+
+  /** Permissions error. */
+  GXIO_ERR_PERM = -1119,
+
+
+
+  /********************************************************/
+  /*                 Test Device Error Codes              */
+  /********************************************************/
+
+  /** Illegal register number. */
+  GXIO_TEST_ERR_REG_NUMBER = -1120,
+
+  /** Illegal buffer slot. */
+  GXIO_TEST_ERR_BUFFER_SLOT = -1121,
+
+
+  /********************************************************/
+  /*                    MPIPE Error Codes                 */
+  /********************************************************/
+
+
+  /** Invalid buffer size. */
+  GXIO_MPIPE_ERR_INVAL_BUFFER_SIZE = -1131,
+
+  /** Cannot allocate buffer stack. */
+  GXIO_MPIPE_ERR_NO_BUFFER_STACK = -1140,
+
+  /** Invalid buffer stack number. */
+  GXIO_MPIPE_ERR_BAD_BUFFER_STACK = -1141,
+
+  /** Cannot allocate NotifRing. */
+  GXIO_MPIPE_ERR_NO_NOTIF_RING = -1142,
+
+  /** Invalid NotifRing number. */
+  GXIO_MPIPE_ERR_BAD_NOTIF_RING = -1143,
+
+  /** Cannot allocate NotifGroup. */
+  GXIO_MPIPE_ERR_NO_NOTIF_GROUP = -1144,
+
+  /** Invalid NotifGroup number. */
+  GXIO_MPIPE_ERR_BAD_NOTIF_GROUP = -1145,
+
+  /** Cannot allocate bucket. */
+  GXIO_MPIPE_ERR_NO_BUCKET = -1146,
+
+  /** Invalid bucket number. */
+  GXIO_MPIPE_ERR_BAD_BUCKET = -1147,
+
+  /** Cannot allocate eDMA ring. */
+  GXIO_MPIPE_ERR_NO_EDMA_RING = -1148,
+
+  /** Invalid eDMA ring number. */
+  GXIO_MPIPE_ERR_BAD_EDMA_RING = -1149,
+
+  /** Invalid channel number. */
+  GXIO_MPIPE_ERR_BAD_CHANNEL = -1150,
+
+  /** Bad configuration. */
+  GXIO_MPIPE_ERR_BAD_CONFIG = -1151,
+
+  /** Empty iqueue. */
+  GXIO_MPIPE_ERR_IQUEUE_EMPTY = -1152,
+
+  /** Empty rules. */
+  GXIO_MPIPE_ERR_RULES_EMPTY = -1160,
+
+  /** Full rules. */
+  GXIO_MPIPE_ERR_RULES_FULL = -1161,
+
+  /** Corrupt rules. */
+  GXIO_MPIPE_ERR_RULES_CORRUPT = -1162,
+
+  /** Invalid rules. */
+  GXIO_MPIPE_ERR_RULES_INVALID = -1163,
+
+  /** Classifier is too big. */
+  GXIO_MPIPE_ERR_CLASSIFIER_TOO_BIG = -1170,
+
+  /** Classifier is too complex. */
+  GXIO_MPIPE_ERR_CLASSIFIER_TOO_COMPLEX = -1171,
+
+  /** Classifier has bad header. */
+  GXIO_MPIPE_ERR_CLASSIFIER_BAD_HEADER = -1172,
+
+  /** Classifier has bad contents. */
+  GXIO_MPIPE_ERR_CLASSIFIER_BAD_CONTENTS = -1173,
+
+  /** Classifier encountered invalid symbol. */
+  GXIO_MPIPE_ERR_CLASSIFIER_INVAL_SYMBOL = -1174,
+
+  /** Classifier encountered invalid bounds. */
+  GXIO_MPIPE_ERR_CLASSIFIER_INVAL_BOUNDS = -1175,
+
+  /** Classifier encountered invalid relocation. */
+  GXIO_MPIPE_ERR_CLASSIFIER_INVAL_RELOCATION = -1176,
+
+  /** Classifier encountered undefined symbol. */
+  GXIO_MPIPE_ERR_CLASSIFIER_UNDEF_SYMBOL = -1177,
+
+
+  /********************************************************/
+  /*                    TRIO  Error Codes                 */
+  /********************************************************/
+
+  /** Cannot allocate memory map region. */
+  GXIO_TRIO_ERR_NO_MEMORY_MAP = -1180,
+
+  /** Invalid memory map region number. */
+  GXIO_TRIO_ERR_BAD_MEMORY_MAP = -1181,
+
+  /** Cannot allocate scatter queue. */
+  GXIO_TRIO_ERR_NO_SCATTER_QUEUE = -1182,
+
+  /** Invalid scatter queue number. */
+  GXIO_TRIO_ERR_BAD_SCATTER_QUEUE = -1183,
+
+  /** Cannot allocate push DMA ring. */
+  GXIO_TRIO_ERR_NO_PUSH_DMA_RING = -1184,
+
+  /** Invalid push DMA ring index. */
+  GXIO_TRIO_ERR_BAD_PUSH_DMA_RING = -1185,
+
+  /** Cannot allocate pull DMA ring. */
+  GXIO_TRIO_ERR_NO_PULL_DMA_RING = -1186,
+
+  /** Invalid pull DMA ring index. */
+  GXIO_TRIO_ERR_BAD_PULL_DMA_RING = -1187,
+
+  /** Cannot allocate PIO region. */
+  GXIO_TRIO_ERR_NO_PIO = -1188,
+
+  /** Invalid PIO region index. */
+  GXIO_TRIO_ERR_BAD_PIO = -1189,
+
+  /** Cannot allocate ASID. */
+  GXIO_TRIO_ERR_NO_ASID = -1190,
+
+  /** Invalid ASID. */
+  GXIO_TRIO_ERR_BAD_ASID = -1191,
+
+
+  /********************************************************/
+  /*                    MICA Error Codes                  */
+  /********************************************************/
+
+  /** No such accelerator type. */
+  GXIO_MICA_ERR_BAD_ACCEL_TYPE = -1220,
+
+  /** Cannot allocate context. */
+  GXIO_MICA_ERR_NO_CONTEXT = -1221,
+
+  /** PKA command queue is full, can't add another command. */
+  GXIO_MICA_ERR_PKA_CMD_QUEUE_FULL = -1222,
+
+  /** PKA result queue is empty, can't get a result from the queue. */
+  GXIO_MICA_ERR_PKA_RESULT_QUEUE_EMPTY = -1223,
+
+  /********************************************************/
+  /*                    GPIO Error Codes                  */
+  /********************************************************/
+
+  /** Pin not available.  Either the physical pin does not exist, or
+   *  it is reserved by the hypervisor for system usage. */
+  GXIO_GPIO_ERR_PIN_UNAVAILABLE = -1240,
+
+  /** Pin busy.  The pin exists, and is available for use via GXIO, but
+   *  it has been attached by some other process or driver. */
+  GXIO_GPIO_ERR_PIN_BUSY = -1241,
+
+  /** Cannot access unattached pin.  One or more of the pins being
+   *  manipulated by this call are not attached to the requesting
+   *  context. */
+  GXIO_GPIO_ERR_PIN_UNATTACHED = -1242,
+
+  /** Invalid I/O mode for pin.  The wiring of the pin in the system
+   *  is such that the I/O mode or electrical control parameters
+   *  requested could cause damage. */
+  GXIO_GPIO_ERR_PIN_INVALID_MODE = -1243,
+
+  /** Smallest iorpc error number. */
+  GXIO_ERR_MIN = -1299
+};
+
+
+#endif /* !_HV_IORPC_H_ */