diff options
Diffstat (limited to 'kernel/arch/tile/gxio/kiorpc.c')
-rw-r--r-- | kernel/arch/tile/gxio/kiorpc.c | 61 |
1 files changed, 61 insertions, 0 deletions
diff --git a/kernel/arch/tile/gxio/kiorpc.c b/kernel/arch/tile/gxio/kiorpc.c new file mode 100644 index 000000000..c8096aa5a --- /dev/null +++ b/kernel/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); |