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37b82b5de7
The GXIO I/O RPC subsystem handles exporting I/O hardware resources to Linux and to applications running under Linux. For instance, memory which is made available for I/O DMA must be mapped by an I/O TLB; that means that such memory must be locked down by Linux, so that it is not swapped or otherwise reused, as long as those I/O TLB entries are active. Similarly, configuring direct hardware access introduces new validation requirements. If a user application registers memory, Linux must ensure that the supplied virtual addresses are valid, and turn them into client physical addresses. Similarly, when Linux then supplies those client physical addresses to the Tilera hypervisor, it must in turn validate those before turning them into the real physical addresses which are required by the hardware. To the extent that these sorts of activities were required on previous TILE architecture processors, they were implemented in a device-specific fashion. This meant that every I/O device had its own Tilera hypervisor driver, its own Linux driver, and in some cases its own user-level library support. There was a large amount of more-or-less functionally identical code in different places, particularly in the different Linux drivers. For TILE-Gx, this support has been generalized into a common framework, known as the I/O RPC framework or just IORPC. The two "gxio" directories (one for headers, one for sources) start with just a few files in each with this infrastructure commit, but after adding support for the on-board I/O shims for networking, PCI, USB, crypto, compression, I2CS, etc., there end up being about 20 files in each directory. More information on the IORPC framework is in the <hv/iorpc.h> header, included in this commit. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
62 lines
1.7 KiB
C
62 lines
1.7 KiB
C
/*
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* Copyright 2012 Tilera Corporation. All Rights Reserved.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation, version 2.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
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* NON INFRINGEMENT. See the GNU General Public License for
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* more details.
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*
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* TILE-Gx IORPC support for kernel I/O drivers.
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*/
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#include <linux/mmzone.h>
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#include <linux/module.h>
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#include <linux/io.h>
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#include <gxio/iorpc_globals.h>
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#include <gxio/kiorpc.h>
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#ifdef DEBUG_IORPC
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#define TRACE(FMT, ...) pr_info(SIMPLE_MSG_LINE FMT, ## __VA_ARGS__)
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#else
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#define TRACE(...)
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#endif
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/* Create kernel-VA-space MMIO mapping for an on-chip IO device. */
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void __iomem *iorpc_ioremap(int hv_fd, resource_size_t offset,
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unsigned long size)
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{
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pgprot_t mmio_base, prot = { 0 };
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unsigned long pfn;
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int err;
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/* Look up the shim's lotar and base PA. */
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err = __iorpc_get_mmio_base(hv_fd, &mmio_base);
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if (err) {
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TRACE("get_mmio_base() failure: %d\n", err);
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return NULL;
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}
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/* Make sure the HV driver approves of our offset and size. */
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err = __iorpc_check_mmio_offset(hv_fd, offset, size);
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if (err) {
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TRACE("check_mmio_offset() failure: %d\n", err);
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return NULL;
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}
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/*
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* mmio_base contains a base pfn and homing coordinates. Turn
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* it into an MMIO pgprot and offset pfn.
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*/
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prot = hv_pte_set_lotar(prot, hv_pte_get_lotar(mmio_base));
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pfn = pte_pfn(mmio_base) + PFN_DOWN(offset);
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return ioremap_prot(PFN_PHYS(pfn), size, prot);
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}
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EXPORT_SYMBOL(iorpc_ioremap);
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