519 lines
12 KiB
C
519 lines
12 KiB
C
/*
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* Copyright IBM Corp. 2012
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*
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* Author(s):
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* Jan Glauber <jang@linux.vnet.ibm.com>
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*/
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#include <linux/kernel.h>
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#include <linux/slab.h>
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#include <linux/export.h>
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#include <linux/iommu-helper.h>
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#include <linux/dma-mapping.h>
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#include <linux/vmalloc.h>
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#include <linux/pci.h>
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#include <asm/pci_dma.h>
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static struct kmem_cache *dma_region_table_cache;
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static struct kmem_cache *dma_page_table_cache;
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static int s390_iommu_strict;
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static int zpci_refresh_global(struct zpci_dev *zdev)
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{
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return zpci_refresh_trans((u64) zdev->fh << 32, zdev->start_dma,
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zdev->iommu_pages * PAGE_SIZE);
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}
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static unsigned long *dma_alloc_cpu_table(void)
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{
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unsigned long *table, *entry;
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table = kmem_cache_alloc(dma_region_table_cache, GFP_ATOMIC);
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if (!table)
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return NULL;
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for (entry = table; entry < table + ZPCI_TABLE_ENTRIES; entry++)
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*entry = ZPCI_TABLE_INVALID | ZPCI_TABLE_PROTECTED;
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return table;
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}
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static void dma_free_cpu_table(void *table)
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{
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kmem_cache_free(dma_region_table_cache, table);
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}
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static unsigned long *dma_alloc_page_table(void)
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{
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unsigned long *table, *entry;
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table = kmem_cache_alloc(dma_page_table_cache, GFP_ATOMIC);
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if (!table)
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return NULL;
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for (entry = table; entry < table + ZPCI_PT_ENTRIES; entry++)
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*entry = ZPCI_PTE_INVALID | ZPCI_TABLE_PROTECTED;
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return table;
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}
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static void dma_free_page_table(void *table)
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{
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kmem_cache_free(dma_page_table_cache, table);
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}
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static unsigned long *dma_get_seg_table_origin(unsigned long *entry)
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{
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unsigned long *sto;
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if (reg_entry_isvalid(*entry))
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sto = get_rt_sto(*entry);
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else {
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sto = dma_alloc_cpu_table();
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if (!sto)
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return NULL;
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set_rt_sto(entry, sto);
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validate_rt_entry(entry);
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entry_clr_protected(entry);
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}
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return sto;
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}
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static unsigned long *dma_get_page_table_origin(unsigned long *entry)
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{
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unsigned long *pto;
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if (reg_entry_isvalid(*entry))
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pto = get_st_pto(*entry);
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else {
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pto = dma_alloc_page_table();
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if (!pto)
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return NULL;
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set_st_pto(entry, pto);
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validate_st_entry(entry);
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entry_clr_protected(entry);
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}
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return pto;
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}
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static unsigned long *dma_walk_cpu_trans(unsigned long *rto, dma_addr_t dma_addr)
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{
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unsigned long *sto, *pto;
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unsigned int rtx, sx, px;
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rtx = calc_rtx(dma_addr);
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sto = dma_get_seg_table_origin(&rto[rtx]);
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if (!sto)
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return NULL;
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sx = calc_sx(dma_addr);
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pto = dma_get_page_table_origin(&sto[sx]);
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if (!pto)
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return NULL;
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px = calc_px(dma_addr);
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return &pto[px];
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}
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static void dma_update_cpu_trans(struct zpci_dev *zdev, void *page_addr,
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dma_addr_t dma_addr, int flags)
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{
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unsigned long *entry;
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entry = dma_walk_cpu_trans(zdev->dma_table, dma_addr);
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if (!entry) {
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WARN_ON_ONCE(1);
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return;
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}
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if (flags & ZPCI_PTE_INVALID) {
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invalidate_pt_entry(entry);
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return;
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} else {
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set_pt_pfaa(entry, page_addr);
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validate_pt_entry(entry);
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}
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if (flags & ZPCI_TABLE_PROTECTED)
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entry_set_protected(entry);
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else
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entry_clr_protected(entry);
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}
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static int dma_update_trans(struct zpci_dev *zdev, unsigned long pa,
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dma_addr_t dma_addr, size_t size, int flags)
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{
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unsigned int nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;
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u8 *page_addr = (u8 *) (pa & PAGE_MASK);
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dma_addr_t start_dma_addr = dma_addr;
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unsigned long irq_flags;
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int i, rc = 0;
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if (!nr_pages)
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return -EINVAL;
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spin_lock_irqsave(&zdev->dma_table_lock, irq_flags);
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if (!zdev->dma_table)
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goto no_refresh;
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for (i = 0; i < nr_pages; i++) {
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dma_update_cpu_trans(zdev, page_addr, dma_addr, flags);
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page_addr += PAGE_SIZE;
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dma_addr += PAGE_SIZE;
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}
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/*
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* With zdev->tlb_refresh == 0, rpcit is not required to establish new
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* translations when previously invalid translation-table entries are
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* validated. With lazy unmap, it also is skipped for previously valid
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* entries, but a global rpcit is then required before any address can
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* be re-used, i.e. after each iommu bitmap wrap-around.
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*/
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if (!zdev->tlb_refresh &&
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(!s390_iommu_strict ||
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((flags & ZPCI_PTE_VALID_MASK) == ZPCI_PTE_VALID)))
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goto no_refresh;
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rc = zpci_refresh_trans((u64) zdev->fh << 32, start_dma_addr,
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nr_pages * PAGE_SIZE);
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no_refresh:
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spin_unlock_irqrestore(&zdev->dma_table_lock, irq_flags);
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return rc;
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}
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static void dma_free_seg_table(unsigned long entry)
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{
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unsigned long *sto = get_rt_sto(entry);
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int sx;
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for (sx = 0; sx < ZPCI_TABLE_ENTRIES; sx++)
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if (reg_entry_isvalid(sto[sx]))
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dma_free_page_table(get_st_pto(sto[sx]));
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dma_free_cpu_table(sto);
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}
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static void dma_cleanup_tables(struct zpci_dev *zdev)
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{
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unsigned long *table;
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int rtx;
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if (!zdev || !zdev->dma_table)
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return;
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table = zdev->dma_table;
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for (rtx = 0; rtx < ZPCI_TABLE_ENTRIES; rtx++)
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if (reg_entry_isvalid(table[rtx]))
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dma_free_seg_table(table[rtx]);
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dma_free_cpu_table(table);
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zdev->dma_table = NULL;
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}
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static unsigned long __dma_alloc_iommu(struct zpci_dev *zdev,
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unsigned long start, int size)
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{
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unsigned long boundary_size;
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boundary_size = ALIGN(dma_get_seg_boundary(&zdev->pdev->dev) + 1,
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PAGE_SIZE) >> PAGE_SHIFT;
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return iommu_area_alloc(zdev->iommu_bitmap, zdev->iommu_pages,
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start, size, 0, boundary_size, 0);
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}
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static unsigned long dma_alloc_iommu(struct zpci_dev *zdev, int size)
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{
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unsigned long offset, flags;
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int wrap = 0;
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spin_lock_irqsave(&zdev->iommu_bitmap_lock, flags);
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offset = __dma_alloc_iommu(zdev, zdev->next_bit, size);
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if (offset == -1) {
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/* wrap-around */
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offset = __dma_alloc_iommu(zdev, 0, size);
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wrap = 1;
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}
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if (offset != -1) {
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zdev->next_bit = offset + size;
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if (!zdev->tlb_refresh && !s390_iommu_strict && wrap)
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/* global flush after wrap-around with lazy unmap */
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zpci_refresh_global(zdev);
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}
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spin_unlock_irqrestore(&zdev->iommu_bitmap_lock, flags);
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return offset;
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}
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static void dma_free_iommu(struct zpci_dev *zdev, unsigned long offset, int size)
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{
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unsigned long flags;
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spin_lock_irqsave(&zdev->iommu_bitmap_lock, flags);
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if (!zdev->iommu_bitmap)
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goto out;
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bitmap_clear(zdev->iommu_bitmap, offset, size);
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/*
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* Lazy flush for unmap: need to move next_bit to avoid address re-use
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* until wrap-around.
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*/
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if (!s390_iommu_strict && offset >= zdev->next_bit)
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zdev->next_bit = offset + size;
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out:
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spin_unlock_irqrestore(&zdev->iommu_bitmap_lock, flags);
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}
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static dma_addr_t s390_dma_map_pages(struct device *dev, struct page *page,
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unsigned long offset, size_t size,
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enum dma_data_direction direction,
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struct dma_attrs *attrs)
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{
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struct zpci_dev *zdev = to_zpci(to_pci_dev(dev));
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unsigned long nr_pages, iommu_page_index;
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unsigned long pa = page_to_phys(page) + offset;
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int flags = ZPCI_PTE_VALID;
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dma_addr_t dma_addr;
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/* This rounds up number of pages based on size and offset */
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nr_pages = iommu_num_pages(pa, size, PAGE_SIZE);
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iommu_page_index = dma_alloc_iommu(zdev, nr_pages);
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if (iommu_page_index == -1)
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goto out_err;
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/* Use rounded up size */
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size = nr_pages * PAGE_SIZE;
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dma_addr = zdev->start_dma + iommu_page_index * PAGE_SIZE;
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if (dma_addr + size > zdev->end_dma)
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goto out_free;
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if (direction == DMA_NONE || direction == DMA_TO_DEVICE)
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flags |= ZPCI_TABLE_PROTECTED;
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if (!dma_update_trans(zdev, pa, dma_addr, size, flags)) {
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atomic64_add(nr_pages, &zdev->mapped_pages);
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return dma_addr + (offset & ~PAGE_MASK);
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}
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out_free:
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dma_free_iommu(zdev, iommu_page_index, nr_pages);
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out_err:
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zpci_err("map error:\n");
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zpci_err_hex(&pa, sizeof(pa));
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return DMA_ERROR_CODE;
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}
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static void s390_dma_unmap_pages(struct device *dev, dma_addr_t dma_addr,
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size_t size, enum dma_data_direction direction,
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struct dma_attrs *attrs)
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{
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struct zpci_dev *zdev = to_zpci(to_pci_dev(dev));
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unsigned long iommu_page_index;
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int npages;
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npages = iommu_num_pages(dma_addr, size, PAGE_SIZE);
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dma_addr = dma_addr & PAGE_MASK;
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if (dma_update_trans(zdev, 0, dma_addr, npages * PAGE_SIZE,
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ZPCI_TABLE_PROTECTED | ZPCI_PTE_INVALID)) {
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zpci_err("unmap error:\n");
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zpci_err_hex(&dma_addr, sizeof(dma_addr));
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}
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atomic64_add(npages, &zdev->unmapped_pages);
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iommu_page_index = (dma_addr - zdev->start_dma) >> PAGE_SHIFT;
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dma_free_iommu(zdev, iommu_page_index, npages);
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}
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static void *s390_dma_alloc(struct device *dev, size_t size,
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dma_addr_t *dma_handle, gfp_t flag,
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struct dma_attrs *attrs)
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{
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struct zpci_dev *zdev = to_zpci(to_pci_dev(dev));
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struct page *page;
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unsigned long pa;
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dma_addr_t map;
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size = PAGE_ALIGN(size);
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page = alloc_pages(flag, get_order(size));
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if (!page)
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return NULL;
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pa = page_to_phys(page);
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memset((void *) pa, 0, size);
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map = s390_dma_map_pages(dev, page, pa % PAGE_SIZE,
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size, DMA_BIDIRECTIONAL, NULL);
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if (dma_mapping_error(dev, map)) {
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free_pages(pa, get_order(size));
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return NULL;
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}
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atomic64_add(size / PAGE_SIZE, &zdev->allocated_pages);
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if (dma_handle)
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*dma_handle = map;
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return (void *) pa;
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}
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static void s390_dma_free(struct device *dev, size_t size,
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void *pa, dma_addr_t dma_handle,
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struct dma_attrs *attrs)
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{
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struct zpci_dev *zdev = to_zpci(to_pci_dev(dev));
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size = PAGE_ALIGN(size);
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atomic64_sub(size / PAGE_SIZE, &zdev->allocated_pages);
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s390_dma_unmap_pages(dev, dma_handle, size, DMA_BIDIRECTIONAL, NULL);
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free_pages((unsigned long) pa, get_order(size));
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}
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static int s390_dma_map_sg(struct device *dev, struct scatterlist *sg,
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int nr_elements, enum dma_data_direction dir,
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struct dma_attrs *attrs)
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{
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int mapped_elements = 0;
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struct scatterlist *s;
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int i;
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for_each_sg(sg, s, nr_elements, i) {
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struct page *page = sg_page(s);
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s->dma_address = s390_dma_map_pages(dev, page, s->offset,
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s->length, dir, NULL);
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if (!dma_mapping_error(dev, s->dma_address)) {
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s->dma_length = s->length;
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mapped_elements++;
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} else
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goto unmap;
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}
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out:
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return mapped_elements;
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unmap:
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for_each_sg(sg, s, mapped_elements, i) {
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if (s->dma_address)
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s390_dma_unmap_pages(dev, s->dma_address, s->dma_length,
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dir, NULL);
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s->dma_address = 0;
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s->dma_length = 0;
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}
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mapped_elements = 0;
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goto out;
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}
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static void s390_dma_unmap_sg(struct device *dev, struct scatterlist *sg,
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int nr_elements, enum dma_data_direction dir,
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struct dma_attrs *attrs)
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{
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struct scatterlist *s;
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int i;
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for_each_sg(sg, s, nr_elements, i) {
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s390_dma_unmap_pages(dev, s->dma_address, s->dma_length, dir, NULL);
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s->dma_address = 0;
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s->dma_length = 0;
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}
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}
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int zpci_dma_init_device(struct zpci_dev *zdev)
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{
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int rc;
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spin_lock_init(&zdev->iommu_bitmap_lock);
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spin_lock_init(&zdev->dma_table_lock);
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zdev->dma_table = dma_alloc_cpu_table();
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if (!zdev->dma_table) {
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rc = -ENOMEM;
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goto out_clean;
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}
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zdev->iommu_size = (unsigned long) high_memory - PAGE_OFFSET;
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zdev->iommu_pages = zdev->iommu_size >> PAGE_SHIFT;
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zdev->iommu_bitmap = vzalloc(zdev->iommu_pages / 8);
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if (!zdev->iommu_bitmap) {
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rc = -ENOMEM;
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goto out_reg;
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}
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rc = zpci_register_ioat(zdev,
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0,
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zdev->start_dma + PAGE_OFFSET,
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zdev->start_dma + zdev->iommu_size - 1,
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(u64) zdev->dma_table);
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if (rc)
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goto out_reg;
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return 0;
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out_reg:
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dma_free_cpu_table(zdev->dma_table);
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out_clean:
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return rc;
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}
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void zpci_dma_exit_device(struct zpci_dev *zdev)
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{
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zpci_unregister_ioat(zdev, 0);
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dma_cleanup_tables(zdev);
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vfree(zdev->iommu_bitmap);
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zdev->iommu_bitmap = NULL;
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zdev->next_bit = 0;
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}
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static int __init dma_alloc_cpu_table_caches(void)
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{
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dma_region_table_cache = kmem_cache_create("PCI_DMA_region_tables",
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ZPCI_TABLE_SIZE, ZPCI_TABLE_ALIGN,
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0, NULL);
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if (!dma_region_table_cache)
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return -ENOMEM;
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dma_page_table_cache = kmem_cache_create("PCI_DMA_page_tables",
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ZPCI_PT_SIZE, ZPCI_PT_ALIGN,
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0, NULL);
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if (!dma_page_table_cache) {
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kmem_cache_destroy(dma_region_table_cache);
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return -ENOMEM;
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}
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return 0;
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}
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int __init zpci_dma_init(void)
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{
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return dma_alloc_cpu_table_caches();
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}
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void zpci_dma_exit(void)
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{
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kmem_cache_destroy(dma_page_table_cache);
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kmem_cache_destroy(dma_region_table_cache);
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}
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#define PREALLOC_DMA_DEBUG_ENTRIES (1 << 16)
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static int __init dma_debug_do_init(void)
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{
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dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
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return 0;
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}
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fs_initcall(dma_debug_do_init);
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struct dma_map_ops s390_dma_ops = {
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.alloc = s390_dma_alloc,
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.free = s390_dma_free,
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.map_sg = s390_dma_map_sg,
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.unmap_sg = s390_dma_unmap_sg,
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.map_page = s390_dma_map_pages,
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.unmap_page = s390_dma_unmap_pages,
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/* if we support direct DMA this must be conditional */
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.is_phys = 0,
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/* dma_supported is unconditionally true without a callback */
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};
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EXPORT_SYMBOL_GPL(s390_dma_ops);
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static int __init s390_iommu_setup(char *str)
|
|
{
|
|
if (!strncmp(str, "strict", 6))
|
|
s390_iommu_strict = 1;
|
|
return 0;
|
|
}
|
|
|
|
__setup("s390_iommu=", s390_iommu_setup);
|