![Krzysztof Kozlowski](/assets/img/avatar_default.png)
The dma-mapping core and the implementations do not change the DMA attributes passed by pointer. Thus the pointer can point to const data. However the attributes do not have to be a bitfield. Instead unsigned long will do fine: 1. This is just simpler. Both in terms of reading the code and setting attributes. Instead of initializing local attributes on the stack and passing pointer to it to dma_set_attr(), just set the bits. 2. It brings safeness and checking for const correctness because the attributes are passed by value. Semantic patches for this change (at least most of them): virtual patch virtual context @r@ identifier f, attrs; @@ f(..., - struct dma_attrs *attrs + unsigned long attrs , ...) { ... } @@ identifier r.f; @@ f(..., - NULL + 0 ) and // Options: --all-includes virtual patch virtual context @r@ identifier f, attrs; type t; @@ t f(..., struct dma_attrs *attrs); @@ identifier r.f; @@ f(..., - NULL + 0 ) Link: http://lkml.kernel.org/r/1468399300-5399-2-git-send-email-k.kozlowski@samsung.com Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> Acked-by: Vineet Gupta <vgupta@synopsys.com> Acked-by: Robin Murphy <robin.murphy@arm.com> Acked-by: Hans-Christian Noren Egtvedt <egtvedt@samfundet.no> Acked-by: Mark Salter <msalter@redhat.com> [c6x] Acked-by: Jesper Nilsson <jesper.nilsson@axis.com> [cris] Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> [drm] Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com> Acked-by: Joerg Roedel <jroedel@suse.de> [iommu] Acked-by: Fabien Dessenne <fabien.dessenne@st.com> [bdisp] Reviewed-by: Marek Szyprowski <m.szyprowski@samsung.com> [vb2-core] Acked-by: David Vrabel <david.vrabel@citrix.com> [xen] Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> [xen swiotlb] Acked-by: Joerg Roedel <jroedel@suse.de> [iommu] Acked-by: Richard Kuo <rkuo@codeaurora.org> [hexagon] Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> [m68k] Acked-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> [s390] Acked-by: Bjorn Andersson <bjorn.andersson@linaro.org> Acked-by: Hans-Christian Noren Egtvedt <egtvedt@samfundet.no> [avr32] Acked-by: Vineet Gupta <vgupta@synopsys.com> [arc] Acked-by: Robin Murphy <robin.murphy@arm.com> [arm64 and dma-iommu] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
471 lines
12 KiB
C
471 lines
12 KiB
C
/*
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* arch/powerpc/sysdev/dart_iommu.c
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*
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* Copyright (C) 2004 Olof Johansson <olof@lixom.net>, IBM Corporation
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* Copyright (C) 2005 Benjamin Herrenschmidt <benh@kernel.crashing.org>,
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* IBM Corporation
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*
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* Based on pSeries_iommu.c:
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* Copyright (C) 2001 Mike Corrigan & Dave Engebretsen, IBM Corporation
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* Copyright (C) 2004 Olof Johansson <olof@lixom.net>, IBM Corporation
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*
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* Dynamic DMA mapping support, Apple U3, U4 & IBM CPC925 "DART" iommu.
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*
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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#include <linux/init.h>
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#include <linux/types.h>
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#include <linux/mm.h>
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#include <linux/spinlock.h>
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#include <linux/string.h>
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#include <linux/pci.h>
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#include <linux/dma-mapping.h>
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#include <linux/vmalloc.h>
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#include <linux/suspend.h>
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#include <linux/memblock.h>
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#include <linux/gfp.h>
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#include <asm/io.h>
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#include <asm/prom.h>
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#include <asm/iommu.h>
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#include <asm/pci-bridge.h>
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#include <asm/machdep.h>
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#include <asm/cacheflush.h>
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#include <asm/ppc-pci.h>
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#include "dart.h"
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/* DART table address and size */
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static u32 *dart_tablebase;
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static unsigned long dart_tablesize;
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/* Mapped base address for the dart */
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static unsigned int __iomem *dart;
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/* Dummy val that entries are set to when unused */
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static unsigned int dart_emptyval;
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static struct iommu_table iommu_table_dart;
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static int iommu_table_dart_inited;
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static int dart_dirty;
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static int dart_is_u4;
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#define DART_U4_BYPASS_BASE 0x8000000000ull
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#define DBG(...)
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static DEFINE_SPINLOCK(invalidate_lock);
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static inline void dart_tlb_invalidate_all(void)
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{
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unsigned long l = 0;
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unsigned int reg, inv_bit;
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unsigned long limit;
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unsigned long flags;
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spin_lock_irqsave(&invalidate_lock, flags);
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DBG("dart: flush\n");
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/* To invalidate the DART, set the DARTCNTL_FLUSHTLB bit in the
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* control register and wait for it to clear.
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*
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* Gotcha: Sometimes, the DART won't detect that the bit gets
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* set. If so, clear it and set it again.
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*/
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limit = 0;
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inv_bit = dart_is_u4 ? DART_CNTL_U4_FLUSHTLB : DART_CNTL_U3_FLUSHTLB;
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retry:
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l = 0;
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reg = DART_IN(DART_CNTL);
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reg |= inv_bit;
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DART_OUT(DART_CNTL, reg);
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while ((DART_IN(DART_CNTL) & inv_bit) && l < (1L << limit))
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l++;
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if (l == (1L << limit)) {
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if (limit < 4) {
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limit++;
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reg = DART_IN(DART_CNTL);
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reg &= ~inv_bit;
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DART_OUT(DART_CNTL, reg);
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goto retry;
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} else
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panic("DART: TLB did not flush after waiting a long "
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"time. Buggy U3 ?");
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}
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spin_unlock_irqrestore(&invalidate_lock, flags);
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}
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static inline void dart_tlb_invalidate_one(unsigned long bus_rpn)
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{
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unsigned int reg;
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unsigned int l, limit;
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unsigned long flags;
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spin_lock_irqsave(&invalidate_lock, flags);
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reg = DART_CNTL_U4_ENABLE | DART_CNTL_U4_IONE |
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(bus_rpn & DART_CNTL_U4_IONE_MASK);
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DART_OUT(DART_CNTL, reg);
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limit = 0;
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wait_more:
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l = 0;
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while ((DART_IN(DART_CNTL) & DART_CNTL_U4_IONE) && l < (1L << limit)) {
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rmb();
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l++;
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}
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if (l == (1L << limit)) {
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if (limit < 4) {
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limit++;
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goto wait_more;
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} else
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panic("DART: TLB did not flush after waiting a long "
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"time. Buggy U4 ?");
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}
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spin_unlock_irqrestore(&invalidate_lock, flags);
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}
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static void dart_cache_sync(unsigned int *base, unsigned int count)
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{
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/*
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* We add 1 to the number of entries to flush, following a
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* comment in Darwin indicating that the memory controller
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* can prefetch unmapped memory under some circumstances.
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*/
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unsigned long start = (unsigned long)base;
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unsigned long end = start + (count + 1) * sizeof(unsigned int);
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unsigned int tmp;
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/* Perform a standard cache flush */
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flush_inval_dcache_range(start, end);
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/*
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* Perform the sequence described in the CPC925 manual to
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* ensure all the data gets to a point the cache incoherent
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* DART hardware will see.
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*/
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asm volatile(" sync;"
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" isync;"
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" dcbf 0,%1;"
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" sync;"
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" isync;"
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" lwz %0,0(%1);"
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" isync" : "=r" (tmp) : "r" (end) : "memory");
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}
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static void dart_flush(struct iommu_table *tbl)
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{
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mb();
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if (dart_dirty) {
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dart_tlb_invalidate_all();
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dart_dirty = 0;
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}
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}
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static int dart_build(struct iommu_table *tbl, long index,
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long npages, unsigned long uaddr,
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enum dma_data_direction direction,
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unsigned long attrs)
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{
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unsigned int *dp, *orig_dp;
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unsigned int rpn;
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long l;
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DBG("dart: build at: %lx, %lx, addr: %x\n", index, npages, uaddr);
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orig_dp = dp = ((unsigned int*)tbl->it_base) + index;
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/* On U3, all memory is contiguous, so we can move this
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* out of the loop.
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*/
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l = npages;
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while (l--) {
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rpn = __pa(uaddr) >> DART_PAGE_SHIFT;
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*(dp++) = DARTMAP_VALID | (rpn & DARTMAP_RPNMASK);
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uaddr += DART_PAGE_SIZE;
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}
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dart_cache_sync(orig_dp, npages);
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if (dart_is_u4) {
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rpn = index;
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while (npages--)
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dart_tlb_invalidate_one(rpn++);
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} else {
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dart_dirty = 1;
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}
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return 0;
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}
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static void dart_free(struct iommu_table *tbl, long index, long npages)
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{
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unsigned int *dp, *orig_dp;
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long orig_npages = npages;
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/* We don't worry about flushing the TLB cache. The only drawback of
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* not doing it is that we won't catch buggy device drivers doing
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* bad DMAs, but then no 32-bit architecture ever does either.
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*/
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DBG("dart: free at: %lx, %lx\n", index, npages);
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orig_dp = dp = ((unsigned int *)tbl->it_base) + index;
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while (npages--)
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*(dp++) = dart_emptyval;
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dart_cache_sync(orig_dp, orig_npages);
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}
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static void allocate_dart(void)
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{
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unsigned long tmp;
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/* 512 pages (2MB) is max DART tablesize. */
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dart_tablesize = 1UL << 21;
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/*
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* 16MB (1 << 24) alignment. We allocate a full 16Mb chuck since we
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* will blow up an entire large page anyway in the kernel mapping.
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*/
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dart_tablebase = __va(memblock_alloc_base(1UL<<24,
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1UL<<24, 0x80000000L));
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/* There is no point scanning the DART space for leaks*/
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kmemleak_no_scan((void *)dart_tablebase);
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/* Allocate a spare page to map all invalid DART pages. We need to do
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* that to work around what looks like a problem with the HT bridge
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* prefetching into invalid pages and corrupting data
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*/
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tmp = memblock_alloc(DART_PAGE_SIZE, DART_PAGE_SIZE);
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dart_emptyval = DARTMAP_VALID | ((tmp >> DART_PAGE_SHIFT) &
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DARTMAP_RPNMASK);
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printk(KERN_INFO "DART table allocated at: %p\n", dart_tablebase);
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}
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static int __init dart_init(struct device_node *dart_node)
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{
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unsigned int i;
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unsigned long base, size;
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struct resource r;
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/* IOMMU disabled by the user ? bail out */
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if (iommu_is_off)
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return -ENODEV;
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/*
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* Only use the DART if the machine has more than 1GB of RAM
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* or if requested with iommu=on on cmdline.
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*
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* 1GB of RAM is picked as limit because some default devices
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* (i.e. Airport Extreme) have 30 bit address range limits.
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*/
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if (!iommu_force_on && memblock_end_of_DRAM() <= 0x40000000ull)
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return -ENODEV;
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/* Get DART registers */
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if (of_address_to_resource(dart_node, 0, &r))
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panic("DART: can't get register base ! ");
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/* Map in DART registers */
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dart = ioremap(r.start, resource_size(&r));
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if (dart == NULL)
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panic("DART: Cannot map registers!");
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/* Allocate the DART and dummy page */
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allocate_dart();
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/* Fill initial table */
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for (i = 0; i < dart_tablesize/4; i++)
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dart_tablebase[i] = dart_emptyval;
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/* Push to memory */
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dart_cache_sync(dart_tablebase, dart_tablesize / sizeof(u32));
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/* Initialize DART with table base and enable it. */
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base = ((unsigned long)dart_tablebase) >> DART_PAGE_SHIFT;
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size = dart_tablesize >> DART_PAGE_SHIFT;
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if (dart_is_u4) {
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size &= DART_SIZE_U4_SIZE_MASK;
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DART_OUT(DART_BASE_U4, base);
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DART_OUT(DART_SIZE_U4, size);
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DART_OUT(DART_CNTL, DART_CNTL_U4_ENABLE);
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} else {
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size &= DART_CNTL_U3_SIZE_MASK;
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DART_OUT(DART_CNTL,
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DART_CNTL_U3_ENABLE |
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(base << DART_CNTL_U3_BASE_SHIFT) |
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(size << DART_CNTL_U3_SIZE_SHIFT));
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}
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/* Invalidate DART to get rid of possible stale TLBs */
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dart_tlb_invalidate_all();
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printk(KERN_INFO "DART IOMMU initialized for %s type chipset\n",
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dart_is_u4 ? "U4" : "U3");
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return 0;
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}
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static struct iommu_table_ops iommu_dart_ops = {
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.set = dart_build,
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.clear = dart_free,
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.flush = dart_flush,
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};
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static void iommu_table_dart_setup(void)
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{
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iommu_table_dart.it_busno = 0;
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iommu_table_dart.it_offset = 0;
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/* it_size is in number of entries */
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iommu_table_dart.it_size = dart_tablesize / sizeof(u32);
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iommu_table_dart.it_page_shift = IOMMU_PAGE_SHIFT_4K;
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/* Initialize the common IOMMU code */
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iommu_table_dart.it_base = (unsigned long)dart_tablebase;
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iommu_table_dart.it_index = 0;
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iommu_table_dart.it_blocksize = 1;
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iommu_table_dart.it_ops = &iommu_dart_ops;
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iommu_init_table(&iommu_table_dart, -1);
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/* Reserve the last page of the DART to avoid possible prefetch
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* past the DART mapped area
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*/
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set_bit(iommu_table_dart.it_size - 1, iommu_table_dart.it_map);
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}
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static void pci_dma_dev_setup_dart(struct pci_dev *dev)
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{
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if (dart_is_u4)
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set_dma_offset(&dev->dev, DART_U4_BYPASS_BASE);
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set_iommu_table_base(&dev->dev, &iommu_table_dart);
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}
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static void pci_dma_bus_setup_dart(struct pci_bus *bus)
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{
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if (!iommu_table_dart_inited) {
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iommu_table_dart_inited = 1;
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iommu_table_dart_setup();
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}
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}
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static bool dart_device_on_pcie(struct device *dev)
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{
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struct device_node *np = of_node_get(dev->of_node);
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while(np) {
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if (of_device_is_compatible(np, "U4-pcie") ||
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of_device_is_compatible(np, "u4-pcie")) {
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of_node_put(np);
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return true;
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}
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np = of_get_next_parent(np);
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}
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return false;
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}
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static int dart_dma_set_mask(struct device *dev, u64 dma_mask)
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{
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if (!dev->dma_mask || !dma_supported(dev, dma_mask))
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return -EIO;
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/* U4 supports a DART bypass, we use it for 64-bit capable
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* devices to improve performances. However, that only works
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* for devices connected to U4 own PCIe interface, not bridged
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* through hypertransport. We need the device to support at
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* least 40 bits of addresses.
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*/
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if (dart_device_on_pcie(dev) && dma_mask >= DMA_BIT_MASK(40)) {
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dev_info(dev, "Using 64-bit DMA iommu bypass\n");
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set_dma_ops(dev, &dma_direct_ops);
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} else {
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dev_info(dev, "Using 32-bit DMA via iommu\n");
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set_dma_ops(dev, &dma_iommu_ops);
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}
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*dev->dma_mask = dma_mask;
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return 0;
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}
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void __init iommu_init_early_dart(struct pci_controller_ops *controller_ops)
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{
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struct device_node *dn;
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/* Find the DART in the device-tree */
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dn = of_find_compatible_node(NULL, "dart", "u3-dart");
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if (dn == NULL) {
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dn = of_find_compatible_node(NULL, "dart", "u4-dart");
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if (dn == NULL)
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return; /* use default direct_dma_ops */
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dart_is_u4 = 1;
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}
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/* Initialize the DART HW */
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if (dart_init(dn) != 0)
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goto bail;
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/* Setup bypass if supported */
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if (dart_is_u4)
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ppc_md.dma_set_mask = dart_dma_set_mask;
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controller_ops->dma_dev_setup = pci_dma_dev_setup_dart;
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controller_ops->dma_bus_setup = pci_dma_bus_setup_dart;
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/* Setup pci_dma ops */
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set_pci_dma_ops(&dma_iommu_ops);
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return;
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bail:
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/* If init failed, use direct iommu and null setup functions */
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controller_ops->dma_dev_setup = NULL;
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controller_ops->dma_bus_setup = NULL;
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/* Setup pci_dma ops */
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set_pci_dma_ops(&dma_direct_ops);
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}
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#ifdef CONFIG_PM
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static void iommu_dart_restore(void)
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{
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dart_cache_sync(dart_tablebase, dart_tablesize / sizeof(u32));
|
|
dart_tlb_invalidate_all();
|
|
}
|
|
|
|
static int __init iommu_init_late_dart(void)
|
|
{
|
|
if (!dart_tablebase)
|
|
return 0;
|
|
|
|
ppc_md.iommu_restore = iommu_dart_restore;
|
|
|
|
return 0;
|
|
}
|
|
|
|
late_initcall(iommu_init_late_dart);
|
|
#endif /* CONFIG_PM */
|