5d2efba64b
The 10Gigabit ethernet device drivers appear to be able to chew up all 256MB of TCE mappings on pSeries systems, as evidenced by numerous error messages: iommu_alloc failed, tbl c0000000010d5c48 vaddr c0000000d875eff0 npages 1 Some experimentation indicates that this is essentially because one 1500 byte ethernet MTU gets mapped as a 64K DMA region when the large 64K pages are enabled. Thus, it doesn't take much to exhaust all of the available DMA mappings for a high-speed card. This patch changes the iommu allocator to work with its own unique, distinct page size. Although the patch is long, its actually quite simple: it just #defines a distinct IOMMU_PAGE_SIZE and then uses this in all the places that matter. As a side effect, it also dramatically improves network performance on platforms with H-calls on iommu translation inserts/removes (since we no longer call it 16 times for a 1500 bytes packet when the iommu HW is still 4k). In the future, we might want to make the IOMMU_PAGE_SIZE a variable in the iommu_table instance, thus allowing support for different HW page sizes in the iommu itself. Signed-off-by: Linas Vepstas <linas@austin.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Acked-by: Olof Johansson <olof@lixom.net> Acked-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Paul Mackerras <paulus@samba.org>
121 lines
4.2 KiB
C
121 lines
4.2 KiB
C
/*
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* Copyright (C) 2001 Mike Corrigan & Dave Engebretsen, IBM Corporation
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* Rewrite, cleanup:
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* Copyright (C) 2004 Olof Johansson <olof@lixom.net>, IBM Corporation
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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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#ifndef _ASM_IOMMU_H
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#define _ASM_IOMMU_H
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#ifdef __KERNEL__
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#include <linux/compiler.h>
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#include <linux/spinlock.h>
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#include <linux/device.h>
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#include <linux/dma-mapping.h>
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#include <asm/types.h>
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#include <asm/bitops.h>
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#define IOMMU_PAGE_SHIFT 12
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#define IOMMU_PAGE_SIZE (ASM_CONST(1) << IOMMU_PAGE_SHIFT)
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#define IOMMU_PAGE_MASK (~((1 << IOMMU_PAGE_SHIFT) - 1))
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#define IOMMU_PAGE_ALIGN(addr) _ALIGN_UP(addr, IOMMU_PAGE_SIZE)
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#ifndef __ASSEMBLY__
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/* Pure 2^n version of get_order */
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static __inline__ __attribute_const__ int get_iommu_order(unsigned long size)
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{
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return __ilog2((size - 1) >> IOMMU_PAGE_SHIFT) + 1;
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}
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#endif /* __ASSEMBLY__ */
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/*
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* IOMAP_MAX_ORDER defines the largest contiguous block
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* of dma space we can get. IOMAP_MAX_ORDER = 13
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* allows up to 2**12 pages (4096 * 4096) = 16 MB
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*/
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#define IOMAP_MAX_ORDER 13
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struct iommu_table {
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unsigned long it_busno; /* Bus number this table belongs to */
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unsigned long it_size; /* Size of iommu table in entries */
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unsigned long it_offset; /* Offset into global table */
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unsigned long it_base; /* mapped address of tce table */
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unsigned long it_index; /* which iommu table this is */
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unsigned long it_type; /* type: PCI or Virtual Bus */
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unsigned long it_blocksize; /* Entries in each block (cacheline) */
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unsigned long it_hint; /* Hint for next alloc */
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unsigned long it_largehint; /* Hint for large allocs */
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unsigned long it_halfpoint; /* Breaking point for small/large allocs */
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spinlock_t it_lock; /* Protects it_map */
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unsigned long *it_map; /* A simple allocation bitmap for now */
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};
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struct scatterlist;
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struct device_node;
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#ifdef CONFIG_PPC_MULTIPLATFORM
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/* Walks all buses and creates iommu tables */
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extern void iommu_setup_pSeries(void);
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extern void iommu_setup_dart(void);
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/* Frees table for an individual device node */
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extern void iommu_free_table(struct device_node *dn);
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#endif /* CONFIG_PPC_MULTIPLATFORM */
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/* Initializes an iommu_table based in values set in the passed-in
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* structure
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*/
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extern struct iommu_table *iommu_init_table(struct iommu_table * tbl,
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int nid);
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extern int iommu_map_sg(struct device *dev, struct iommu_table *tbl,
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struct scatterlist *sglist, int nelems, unsigned long mask,
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enum dma_data_direction direction);
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extern void iommu_unmap_sg(struct iommu_table *tbl, struct scatterlist *sglist,
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int nelems, enum dma_data_direction direction);
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extern void *iommu_alloc_coherent(struct iommu_table *tbl, size_t size,
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dma_addr_t *dma_handle, unsigned long mask,
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gfp_t flag, int node);
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extern void iommu_free_coherent(struct iommu_table *tbl, size_t size,
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void *vaddr, dma_addr_t dma_handle);
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extern dma_addr_t iommu_map_single(struct iommu_table *tbl, void *vaddr,
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size_t size, unsigned long mask,
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enum dma_data_direction direction);
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extern void iommu_unmap_single(struct iommu_table *tbl, dma_addr_t dma_handle,
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size_t size, enum dma_data_direction direction);
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extern void iommu_init_early_pSeries(void);
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extern void iommu_init_early_iSeries(void);
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extern void iommu_init_early_dart(void);
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#ifdef CONFIG_PCI
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extern void pci_iommu_init(void);
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extern void pci_direct_iommu_init(void);
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#else
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static inline void pci_iommu_init(void) { }
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#endif
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extern void alloc_dart_table(void);
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#endif /* __KERNEL__ */
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#endif /* _ASM_IOMMU_H */
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