diff options
Diffstat (limited to 'arch/powerpc/platforms/cell/iommu.c')
| -rw-r--r-- | arch/powerpc/platforms/cell/iommu.c | 1094 |
1 files changed, 1094 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/cell/iommu.c b/arch/powerpc/platforms/cell/iommu.c new file mode 100644 index 000000000..1202a69b0 --- /dev/null +++ b/arch/powerpc/platforms/cell/iommu.c @@ -0,0 +1,1094 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * IOMMU implementation for Cell Broadband Processor Architecture + * + * (C) Copyright IBM Corporation 2006-2008 + * + * Author: Jeremy Kerr <jk@ozlabs.org> + */ + +#undef DEBUG + +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/irqdomain.h> +#include <linux/notifier.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/platform_device.h> +#include <linux/slab.h> +#include <linux/memblock.h> + +#include <asm/prom.h> +#include <asm/iommu.h> +#include <asm/machdep.h> +#include <asm/pci-bridge.h> +#include <asm/udbg.h> +#include <asm/firmware.h> +#include <asm/cell-regs.h> + +#include "cell.h" +#include "interrupt.h" + +/* Define CELL_IOMMU_REAL_UNMAP to actually unmap non-used pages + * instead of leaving them mapped to some dummy page. This can be + * enabled once the appropriate workarounds for spider bugs have + * been enabled + */ +#define CELL_IOMMU_REAL_UNMAP + +/* Define CELL_IOMMU_STRICT_PROTECTION to enforce protection of + * IO PTEs based on the transfer direction. That can be enabled + * once spider-net has been fixed to pass the correct direction + * to the DMA mapping functions + */ +#define CELL_IOMMU_STRICT_PROTECTION + + +#define NR_IOMMUS 2 + +/* IOC mmap registers */ +#define IOC_Reg_Size 0x2000 + +#define IOC_IOPT_CacheInvd 0x908 +#define IOC_IOPT_CacheInvd_NE_Mask 0xffe0000000000000ul +#define IOC_IOPT_CacheInvd_IOPTE_Mask 0x000003fffffffff8ul +#define IOC_IOPT_CacheInvd_Busy 0x0000000000000001ul + +#define IOC_IOST_Origin 0x918 +#define IOC_IOST_Origin_E 0x8000000000000000ul +#define IOC_IOST_Origin_HW 0x0000000000000800ul +#define IOC_IOST_Origin_HL 0x0000000000000400ul + +#define IOC_IO_ExcpStat 0x920 +#define IOC_IO_ExcpStat_V 0x8000000000000000ul +#define IOC_IO_ExcpStat_SPF_Mask 0x6000000000000000ul +#define IOC_IO_ExcpStat_SPF_S 0x6000000000000000ul +#define IOC_IO_ExcpStat_SPF_P 0x2000000000000000ul +#define IOC_IO_ExcpStat_ADDR_Mask 0x00000007fffff000ul +#define IOC_IO_ExcpStat_RW_Mask 0x0000000000000800ul +#define IOC_IO_ExcpStat_IOID_Mask 0x00000000000007fful + +#define IOC_IO_ExcpMask 0x928 +#define IOC_IO_ExcpMask_SFE 0x4000000000000000ul +#define IOC_IO_ExcpMask_PFE 0x2000000000000000ul + +#define IOC_IOCmd_Offset 0x1000 + +#define IOC_IOCmd_Cfg 0xc00 +#define IOC_IOCmd_Cfg_TE 0x0000800000000000ul + + +/* Segment table entries */ +#define IOSTE_V 0x8000000000000000ul /* valid */ +#define IOSTE_H 0x4000000000000000ul /* cache hint */ +#define IOSTE_PT_Base_RPN_Mask 0x3ffffffffffff000ul /* base RPN of IOPT */ +#define IOSTE_NPPT_Mask 0x0000000000000fe0ul /* no. pages in IOPT */ +#define IOSTE_PS_Mask 0x0000000000000007ul /* page size */ +#define IOSTE_PS_4K 0x0000000000000001ul /* - 4kB */ +#define IOSTE_PS_64K 0x0000000000000003ul /* - 64kB */ +#define IOSTE_PS_1M 0x0000000000000005ul /* - 1MB */ +#define IOSTE_PS_16M 0x0000000000000007ul /* - 16MB */ + + +/* IOMMU sizing */ +#define IO_SEGMENT_SHIFT 28 +#define IO_PAGENO_BITS(shift) (IO_SEGMENT_SHIFT - (shift)) + +/* The high bit needs to be set on every DMA address */ +#define SPIDER_DMA_OFFSET 0x80000000ul + +struct iommu_window { + struct list_head list; + struct cbe_iommu *iommu; + unsigned long offset; + unsigned long size; + unsigned int ioid; + struct iommu_table table; +}; + +#define NAMESIZE 8 +struct cbe_iommu { + int nid; + char name[NAMESIZE]; + void __iomem *xlate_regs; + void __iomem *cmd_regs; + unsigned long *stab; + unsigned long *ptab; + void *pad_page; + struct list_head windows; +}; + +/* Static array of iommus, one per node + * each contains a list of windows, keyed from dma_window property + * - on bus setup, look for a matching window, or create one + * - on dev setup, assign iommu_table ptr + */ +static struct cbe_iommu iommus[NR_IOMMUS]; +static int cbe_nr_iommus; + +static void invalidate_tce_cache(struct cbe_iommu *iommu, unsigned long *pte, + long n_ptes) +{ + u64 __iomem *reg; + u64 val; + long n; + + reg = iommu->xlate_regs + IOC_IOPT_CacheInvd; + + while (n_ptes > 0) { + /* we can invalidate up to 1 << 11 PTEs at once */ + n = min(n_ptes, 1l << 11); + val = (((n /*- 1*/) << 53) & IOC_IOPT_CacheInvd_NE_Mask) + | (__pa(pte) & IOC_IOPT_CacheInvd_IOPTE_Mask) + | IOC_IOPT_CacheInvd_Busy; + + out_be64(reg, val); + while (in_be64(reg) & IOC_IOPT_CacheInvd_Busy) + ; + + n_ptes -= n; + pte += n; + } +} + +static int tce_build_cell(struct iommu_table *tbl, long index, long npages, + unsigned long uaddr, enum dma_data_direction direction, + unsigned long attrs) +{ + int i; + unsigned long *io_pte, base_pte; + struct iommu_window *window = + container_of(tbl, struct iommu_window, table); + + /* implementing proper protection causes problems with the spidernet + * driver - check mapping directions later, but allow read & write by + * default for now.*/ +#ifdef CELL_IOMMU_STRICT_PROTECTION + /* to avoid referencing a global, we use a trick here to setup the + * protection bit. "prot" is setup to be 3 fields of 4 bits appended + * together for each of the 3 supported direction values. It is then + * shifted left so that the fields matching the desired direction + * lands on the appropriate bits, and other bits are masked out. + */ + const unsigned long prot = 0xc48; + base_pte = + ((prot << (52 + 4 * direction)) & + (CBE_IOPTE_PP_W | CBE_IOPTE_PP_R)) | + CBE_IOPTE_M | CBE_IOPTE_SO_RW | + (window->ioid & CBE_IOPTE_IOID_Mask); +#else + base_pte = CBE_IOPTE_PP_W | CBE_IOPTE_PP_R | CBE_IOPTE_M | + CBE_IOPTE_SO_RW | (window->ioid & CBE_IOPTE_IOID_Mask); +#endif + if (unlikely(attrs & DMA_ATTR_WEAK_ORDERING)) + base_pte &= ~CBE_IOPTE_SO_RW; + + io_pte = (unsigned long *)tbl->it_base + (index - tbl->it_offset); + + for (i = 0; i < npages; i++, uaddr += (1 << tbl->it_page_shift)) + io_pte[i] = base_pte | (__pa(uaddr) & CBE_IOPTE_RPN_Mask); + + mb(); + + invalidate_tce_cache(window->iommu, io_pte, npages); + + pr_debug("tce_build_cell(index=%lx,n=%lx,dir=%d,base_pte=%lx)\n", + index, npages, direction, base_pte); + return 0; +} + +static void tce_free_cell(struct iommu_table *tbl, long index, long npages) +{ + + int i; + unsigned long *io_pte, pte; + struct iommu_window *window = + container_of(tbl, struct iommu_window, table); + + pr_debug("tce_free_cell(index=%lx,n=%lx)\n", index, npages); + +#ifdef CELL_IOMMU_REAL_UNMAP + pte = 0; +#else + /* spider bridge does PCI reads after freeing - insert a mapping + * to a scratch page instead of an invalid entry */ + pte = CBE_IOPTE_PP_R | CBE_IOPTE_M | CBE_IOPTE_SO_RW | + __pa(window->iommu->pad_page) | + (window->ioid & CBE_IOPTE_IOID_Mask); +#endif + + io_pte = (unsigned long *)tbl->it_base + (index - tbl->it_offset); + + for (i = 0; i < npages; i++) + io_pte[i] = pte; + + mb(); + + invalidate_tce_cache(window->iommu, io_pte, npages); +} + +static irqreturn_t ioc_interrupt(int irq, void *data) +{ + unsigned long stat, spf; + struct cbe_iommu *iommu = data; + + stat = in_be64(iommu->xlate_regs + IOC_IO_ExcpStat); + spf = stat & IOC_IO_ExcpStat_SPF_Mask; + + /* Might want to rate limit it */ + printk(KERN_ERR "iommu: DMA exception 0x%016lx\n", stat); + printk(KERN_ERR " V=%d, SPF=[%c%c], RW=%s, IOID=0x%04x\n", + !!(stat & IOC_IO_ExcpStat_V), + (spf == IOC_IO_ExcpStat_SPF_S) ? 'S' : ' ', + (spf == IOC_IO_ExcpStat_SPF_P) ? 'P' : ' ', + (stat & IOC_IO_ExcpStat_RW_Mask) ? "Read" : "Write", + (unsigned int)(stat & IOC_IO_ExcpStat_IOID_Mask)); + printk(KERN_ERR " page=0x%016lx\n", + stat & IOC_IO_ExcpStat_ADDR_Mask); + + /* clear interrupt */ + stat &= ~IOC_IO_ExcpStat_V; + out_be64(iommu->xlate_regs + IOC_IO_ExcpStat, stat); + + return IRQ_HANDLED; +} + +static int __init cell_iommu_find_ioc(int nid, unsigned long *base) +{ + struct device_node *np; + struct resource r; + + *base = 0; + + /* First look for new style /be nodes */ + for_each_node_by_name(np, "ioc") { + if (of_node_to_nid(np) != nid) + continue; + if (of_address_to_resource(np, 0, &r)) { + printk(KERN_ERR "iommu: can't get address for %pOF\n", + np); + continue; + } + *base = r.start; + of_node_put(np); + return 0; + } + + /* Ok, let's try the old way */ + for_each_node_by_type(np, "cpu") { + const unsigned int *nidp; + const unsigned long *tmp; + + nidp = of_get_property(np, "node-id", NULL); + if (nidp && *nidp == nid) { + tmp = of_get_property(np, "ioc-translation", NULL); + if (tmp) { + *base = *tmp; + of_node_put(np); + return 0; + } + } + } + + return -ENODEV; +} + +static void __init cell_iommu_setup_stab(struct cbe_iommu *iommu, + unsigned long dbase, unsigned long dsize, + unsigned long fbase, unsigned long fsize) +{ + struct page *page; + unsigned long segments, stab_size; + + segments = max(dbase + dsize, fbase + fsize) >> IO_SEGMENT_SHIFT; + + pr_debug("%s: iommu[%d]: segments: %lu\n", + __func__, iommu->nid, segments); + + /* set up the segment table */ + stab_size = segments * sizeof(unsigned long); + page = alloc_pages_node(iommu->nid, GFP_KERNEL, get_order(stab_size)); + BUG_ON(!page); + iommu->stab = page_address(page); + memset(iommu->stab, 0, stab_size); +} + +static unsigned long *__init cell_iommu_alloc_ptab(struct cbe_iommu *iommu, + unsigned long base, unsigned long size, unsigned long gap_base, + unsigned long gap_size, unsigned long page_shift) +{ + struct page *page; + int i; + unsigned long reg, segments, pages_per_segment, ptab_size, + n_pte_pages, start_seg, *ptab; + + start_seg = base >> IO_SEGMENT_SHIFT; + segments = size >> IO_SEGMENT_SHIFT; + pages_per_segment = 1ull << IO_PAGENO_BITS(page_shift); + /* PTEs for each segment must start on a 4K boundary */ + pages_per_segment = max(pages_per_segment, + (1 << 12) / sizeof(unsigned long)); + + ptab_size = segments * pages_per_segment * sizeof(unsigned long); + pr_debug("%s: iommu[%d]: ptab_size: %lu, order: %d\n", __func__, + iommu->nid, ptab_size, get_order(ptab_size)); + page = alloc_pages_node(iommu->nid, GFP_KERNEL, get_order(ptab_size)); + BUG_ON(!page); + + ptab = page_address(page); + memset(ptab, 0, ptab_size); + + /* number of 4K pages needed for a page table */ + n_pte_pages = (pages_per_segment * sizeof(unsigned long)) >> 12; + + pr_debug("%s: iommu[%d]: stab at %p, ptab at %p, n_pte_pages: %lu\n", + __func__, iommu->nid, iommu->stab, ptab, + n_pte_pages); + + /* initialise the STEs */ + reg = IOSTE_V | ((n_pte_pages - 1) << 5); + + switch (page_shift) { + case 12: reg |= IOSTE_PS_4K; break; + case 16: reg |= IOSTE_PS_64K; break; + case 20: reg |= IOSTE_PS_1M; break; + case 24: reg |= IOSTE_PS_16M; break; + default: BUG(); + } + + gap_base = gap_base >> IO_SEGMENT_SHIFT; + gap_size = gap_size >> IO_SEGMENT_SHIFT; + + pr_debug("Setting up IOMMU stab:\n"); + for (i = start_seg; i < (start_seg + segments); i++) { + if (i >= gap_base && i < (gap_base + gap_size)) { + pr_debug("\toverlap at %d, skipping\n", i); + continue; + } + iommu->stab[i] = reg | (__pa(ptab) + (n_pte_pages << 12) * + (i - start_seg)); + pr_debug("\t[%d] 0x%016lx\n", i, iommu->stab[i]); + } + + return ptab; +} + +static void __init cell_iommu_enable_hardware(struct cbe_iommu *iommu) +{ + int ret; + unsigned long reg, xlate_base; + unsigned int virq; + + if (cell_iommu_find_ioc(iommu->nid, &xlate_base)) + panic("%s: missing IOC register mappings for node %d\n", + __func__, iommu->nid); + + iommu->xlate_regs = ioremap(xlate_base, IOC_Reg_Size); + iommu->cmd_regs = iommu->xlate_regs + IOC_IOCmd_Offset; + + /* ensure that the STEs have updated */ + mb(); + + /* setup interrupts for the iommu. */ + reg = in_be64(iommu->xlate_regs + IOC_IO_ExcpStat); + out_be64(iommu->xlate_regs + IOC_IO_ExcpStat, + reg & ~IOC_IO_ExcpStat_V); + out_be64(iommu->xlate_regs + IOC_IO_ExcpMask, + IOC_IO_ExcpMask_PFE | IOC_IO_ExcpMask_SFE); + + virq = irq_create_mapping(NULL, + IIC_IRQ_IOEX_ATI | (iommu->nid << IIC_IRQ_NODE_SHIFT)); + BUG_ON(!virq); + + ret = request_irq(virq, ioc_interrupt, 0, iommu->name, iommu); + BUG_ON(ret); + + /* set the IOC segment table origin register (and turn on the iommu) */ + reg = IOC_IOST_Origin_E | __pa(iommu->stab) | IOC_IOST_Origin_HW; + out_be64(iommu->xlate_regs + IOC_IOST_Origin, reg); + in_be64(iommu->xlate_regs + IOC_IOST_Origin); + + /* turn on IO translation */ + reg = in_be64(iommu->cmd_regs + IOC_IOCmd_Cfg) | IOC_IOCmd_Cfg_TE; + out_be64(iommu->cmd_regs + IOC_IOCmd_Cfg, reg); +} + +static void __init cell_iommu_setup_hardware(struct cbe_iommu *iommu, + unsigned long base, unsigned long size) +{ + cell_iommu_setup_stab(iommu, base, size, 0, 0); + iommu->ptab = cell_iommu_alloc_ptab(iommu, base, size, 0, 0, + IOMMU_PAGE_SHIFT_4K); + cell_iommu_enable_hardware(iommu); +} + +#if 0/* Unused for now */ +static struct iommu_window *find_window(struct cbe_iommu *iommu, + unsigned long offset, unsigned long size) +{ + struct iommu_window *window; + + /* todo: check for overlapping (but not equal) windows) */ + + list_for_each_entry(window, &(iommu->windows), list) { + if (window->offset == offset && window->size == size) + return window; + } + + return NULL; +} +#endif + +static inline u32 cell_iommu_get_ioid(struct device_node *np) +{ + const u32 *ioid; + + ioid = of_get_property(np, "ioid", NULL); + if (ioid == NULL) { + printk(KERN_WARNING "iommu: missing ioid for %pOF using 0\n", + np); + return 0; + } + + return *ioid; +} + +static struct iommu_table_ops cell_iommu_ops = { + .set = tce_build_cell, + .clear = tce_free_cell +}; + +static struct iommu_window * __init +cell_iommu_setup_window(struct cbe_iommu *iommu, struct device_node *np, + unsigned long offset, unsigned long size, + unsigned long pte_offset) +{ + struct iommu_window *window; + struct page *page; + u32 ioid; + + ioid = cell_iommu_get_ioid(np); + + window = kzalloc_node(sizeof(*window), GFP_KERNEL, iommu->nid); + BUG_ON(window == NULL); + + window->offset = offset; + window->size = size; + window->ioid = ioid; + window->iommu = iommu; + + window->table.it_blocksize = 16; + window->table.it_base = (unsigned long)iommu->ptab; + window->table.it_index = iommu->nid; + window->table.it_page_shift = IOMMU_PAGE_SHIFT_4K; + window->table.it_offset = + (offset >> window->table.it_page_shift) + pte_offset; + window->table.it_size = size >> window->table.it_page_shift; + window->table.it_ops = &cell_iommu_ops; + + if (!iommu_init_table(&window->table, iommu->nid, 0, 0)) + panic("Failed to initialize iommu table"); + + pr_debug("\tioid %d\n", window->ioid); + pr_debug("\tblocksize %ld\n", window->table.it_blocksize); + pr_debug("\tbase 0x%016lx\n", window->table.it_base); + pr_debug("\toffset 0x%lx\n", window->table.it_offset); + pr_debug("\tsize %ld\n", window->table.it_size); + + list_add(&window->list, &iommu->windows); + + if (offset != 0) + return window; + + /* We need to map and reserve the first IOMMU page since it's used + * by the spider workaround. In theory, we only need to do that when + * running on spider but it doesn't really matter. + * + * This code also assumes that we have a window that starts at 0, + * which is the case on all spider based blades. + */ + page = alloc_pages_node(iommu->nid, GFP_KERNEL, 0); + BUG_ON(!page); + iommu->pad_page = page_address(page); + clear_page(iommu->pad_page); + + __set_bit(0, window->table.it_map); + tce_build_cell(&window->table, window->table.it_offset, 1, + (unsigned long)iommu->pad_page, DMA_TO_DEVICE, 0); + + return window; +} + +static struct cbe_iommu *cell_iommu_for_node(int nid) +{ + int i; + + for (i = 0; i < cbe_nr_iommus; i++) + if (iommus[i].nid == nid) + return &iommus[i]; + return NULL; +} + +static unsigned long cell_dma_nommu_offset; + +static unsigned long dma_iommu_fixed_base; +static bool cell_iommu_enabled; + +/* iommu_fixed_is_weak is set if booted with iommu_fixed=weak */ +bool iommu_fixed_is_weak; + +static struct iommu_table *cell_get_iommu_table(struct device *dev) +{ + struct iommu_window *window; + struct cbe_iommu *iommu; + + /* Current implementation uses the first window available in that + * node's iommu. We -might- do something smarter later though it may + * never be necessary + */ + iommu = cell_iommu_for_node(dev_to_node(dev)); + if (iommu == NULL || list_empty(&iommu->windows)) { + dev_err(dev, "iommu: missing iommu for %pOF (node %d)\n", + dev->of_node, dev_to_node(dev)); + return NULL; + } + window = list_entry(iommu->windows.next, struct iommu_window, list); + + return &window->table; +} + +static u64 cell_iommu_get_fixed_address(struct device *dev); + +static void cell_dma_dev_setup(struct device *dev) +{ + if (cell_iommu_enabled) { + u64 addr = cell_iommu_get_fixed_address(dev); + + if (addr != OF_BAD_ADDR) + dev->archdata.dma_offset = addr + dma_iommu_fixed_base; + set_iommu_table_base(dev, cell_get_iommu_table(dev)); + } else { + dev->archdata.dma_offset = cell_dma_nommu_offset; + } +} + +static void cell_pci_dma_dev_setup(struct pci_dev *dev) +{ + cell_dma_dev_setup(&dev->dev); +} + +static int cell_of_bus_notify(struct notifier_block *nb, unsigned long action, + void *data) +{ + struct device *dev = data; + + /* We are only interested in device addition */ + if (action != BUS_NOTIFY_ADD_DEVICE) + return 0; + + if (cell_iommu_enabled) + dev->dma_ops = &dma_iommu_ops; + cell_dma_dev_setup(dev); + return 0; +} + +static struct notifier_block cell_of_bus_notifier = { + .notifier_call = cell_of_bus_notify +}; + +static int __init cell_iommu_get_window(struct device_node *np, + unsigned long *base, + unsigned long *size) +{ + const __be32 *dma_window; + unsigned long index; + + /* Use ibm,dma-window if available, else, hard code ! */ + dma_window = of_get_property(np, "ibm,dma-window", NULL); + if (dma_window == NULL) { + *base = 0; + *size = 0x80000000u; + return -ENODEV; + } + + of_parse_dma_window(np, dma_window, &index, base, size); + return 0; +} + +static struct cbe_iommu * __init cell_iommu_alloc(struct device_node *np) +{ + struct cbe_iommu *iommu; + int nid, i; + + /* Get node ID */ + nid = of_node_to_nid(np); + if (nid < 0) { + printk(KERN_ERR "iommu: failed to get node for %pOF\n", + np); + return NULL; + } + pr_debug("iommu: setting up iommu for node %d (%pOF)\n", + nid, np); + + /* XXX todo: If we can have multiple windows on the same IOMMU, which + * isn't the case today, we probably want here to check whether the + * iommu for that node is already setup. + * However, there might be issue with getting the size right so let's + * ignore that for now. We might want to completely get rid of the + * multiple window support since the cell iommu supports per-page ioids + */ + + if (cbe_nr_iommus >= NR_IOMMUS) { + printk(KERN_ERR "iommu: too many IOMMUs detected ! (%pOF)\n", + np); + return NULL; + } + + /* Init base fields */ + i = cbe_nr_iommus++; + iommu = &iommus[i]; + iommu->stab = NULL; + iommu->nid = nid; + snprintf(iommu->name, sizeof(iommu->name), "iommu%d", i); + INIT_LIST_HEAD(&iommu->windows); + + return iommu; +} + +static void __init cell_iommu_init_one(struct device_node *np, + unsigned long offset) +{ + struct cbe_iommu *iommu; + unsigned long base, size; + + iommu = cell_iommu_alloc(np); + if (!iommu) + return; + + /* Obtain a window for it */ + cell_iommu_get_window(np, &base, &size); + + pr_debug("\ttranslating window 0x%lx...0x%lx\n", + base, base + size - 1); + + /* Initialize the hardware */ + cell_iommu_setup_hardware(iommu, base, size); + + /* Setup the iommu_table */ + cell_iommu_setup_window(iommu, np, base, size, + offset >> IOMMU_PAGE_SHIFT_4K); +} + +static void __init cell_disable_iommus(void) +{ + int node; + unsigned long base, val; + void __iomem *xregs, *cregs; + + /* Make sure IOC translation is disabled on all nodes */ + for_each_online_node(node) { + if (cell_iommu_find_ioc(node, &base)) + continue; + xregs = ioremap(base, IOC_Reg_Size); + if (xregs == NULL) + continue; + cregs = xregs + IOC_IOCmd_Offset; + + pr_debug("iommu: cleaning up iommu on node %d\n", node); + + out_be64(xregs + IOC_IOST_Origin, 0); + (void)in_be64(xregs + IOC_IOST_Origin); + val = in_be64(cregs + IOC_IOCmd_Cfg); + val &= ~IOC_IOCmd_Cfg_TE; + out_be64(cregs + IOC_IOCmd_Cfg, val); + (void)in_be64(cregs + IOC_IOCmd_Cfg); + + iounmap(xregs); + } +} + +static int __init cell_iommu_init_disabled(void) +{ + struct device_node *np = NULL; + unsigned long base = 0, size; + + /* When no iommu is present, we use direct DMA ops */ + + /* First make sure all IOC translation is turned off */ + cell_disable_iommus(); + + /* If we have no Axon, we set up the spider DMA magic offset */ + np = of_find_node_by_name(NULL, "axon"); + if (!np) + cell_dma_nommu_offset = SPIDER_DMA_OFFSET; + of_node_put(np); + + /* Now we need to check to see where the memory is mapped + * in PCI space. We assume that all busses use the same dma + * window which is always the case so far on Cell, thus we + * pick up the first pci-internal node we can find and check + * the DMA window from there. + */ + for_each_node_by_name(np, "axon") { + if (np->parent == NULL || np->parent->parent != NULL) + continue; + if (cell_iommu_get_window(np, &base, &size) == 0) + break; + } + if (np == NULL) { + for_each_node_by_name(np, "pci-internal") { + if (np->parent == NULL || np->parent->parent != NULL) + continue; + if (cell_iommu_get_window(np, &base, &size) == 0) + break; + } + } + of_node_put(np); + + /* If we found a DMA window, we check if it's big enough to enclose + * all of physical memory. If not, we force enable IOMMU + */ + if (np && size < memblock_end_of_DRAM()) { + printk(KERN_WARNING "iommu: force-enabled, dma window" + " (%ldMB) smaller than total memory (%lldMB)\n", + size >> 20, memblock_end_of_DRAM() >> 20); + return -ENODEV; + } + + cell_dma_nommu_offset += base; + + if (cell_dma_nommu_offset != 0) + cell_pci_controller_ops.dma_dev_setup = cell_pci_dma_dev_setup; + + printk("iommu: disabled, direct DMA offset is 0x%lx\n", + cell_dma_nommu_offset); + + return 0; +} + +/* + * Fixed IOMMU mapping support + * + * This code adds support for setting up a fixed IOMMU mapping on certain + * cell machines. For 64-bit devices this avoids the performance overhead of + * mapping and unmapping pages at runtime. 32-bit devices are unable to use + * the fixed mapping. + * + * The fixed mapping is established at boot, and maps all of physical memory + * 1:1 into device space at some offset. On machines with < 30 GB of memory + * we setup the fixed mapping immediately above the normal IOMMU window. + * + * For example a machine with 4GB of memory would end up with the normal + * IOMMU window from 0-2GB and the fixed mapping window from 2GB to 6GB. In + * this case a 64-bit device wishing to DMA to 1GB would be told to DMA to + * 3GB, plus any offset required by firmware. The firmware offset is encoded + * in the "dma-ranges" property. + * + * On machines with 30GB or more of memory, we are unable to place the fixed + * mapping above the normal IOMMU window as we would run out of address space. + * Instead we move the normal IOMMU window to coincide with the hash page + * table, this region does not need to be part of the fixed mapping as no + * device should ever be DMA'ing to it. We then setup the fixed mapping + * from 0 to 32GB. + */ + +static u64 cell_iommu_get_fixed_address(struct device *dev) +{ + u64 cpu_addr, size, best_size, dev_addr = OF_BAD_ADDR; + struct device_node *np; + const u32 *ranges = NULL; + int i, len, best, naddr, nsize, pna, range_size; + + /* We can be called for platform devices that have no of_node */ + np = of_node_get(dev->of_node); + if (!np) + goto out; + + while (1) { + naddr = of_n_addr_cells(np); + nsize = of_n_size_cells(np); + np = of_get_next_parent(np); + if (!np) + break; + + ranges = of_get_property(np, "dma-ranges", &len); + + /* Ignore empty ranges, they imply no translation required */ + if (ranges && len > 0) + break; + } + + if (!ranges) { + dev_dbg(dev, "iommu: no dma-ranges found\n"); + goto out; + } + + len /= sizeof(u32); + + pna = of_n_addr_cells(np); + range_size = naddr + nsize + pna; + + /* dma-ranges format: + * child addr : naddr cells + * parent addr : pna cells + * size : nsize cells + */ + for (i = 0, best = -1, best_size = 0; i < len; i += range_size) { + cpu_addr = of_translate_dma_address(np, ranges + i + naddr); + size = of_read_number(ranges + i + naddr + pna, nsize); + + if (cpu_addr == 0 && size > best_size) { + best = i; + best_size = size; + } + } + + if (best >= 0) { + dev_addr = of_read_number(ranges + best, naddr); + } else + dev_dbg(dev, "iommu: no suitable range found!\n"); + +out: + of_node_put(np); + + return dev_addr; +} + +static bool cell_pci_iommu_bypass_supported(struct pci_dev *pdev, u64 mask) +{ + return mask == DMA_BIT_MASK(64) && + cell_iommu_get_fixed_address(&pdev->dev) != OF_BAD_ADDR; +} + +static void __init insert_16M_pte(unsigned long addr, unsigned long *ptab, + unsigned long base_pte) +{ + unsigned long segment, offset; + + segment = addr >> IO_SEGMENT_SHIFT; + offset = (addr >> 24) - (segment << IO_PAGENO_BITS(24)); + ptab = ptab + (segment * (1 << 12) / sizeof(unsigned long)); + + pr_debug("iommu: addr %lx ptab %p segment %lx offset %lx\n", + addr, ptab, segment, offset); + + ptab[offset] = base_pte | (__pa(addr) & CBE_IOPTE_RPN_Mask); +} + +static void __init cell_iommu_setup_fixed_ptab(struct cbe_iommu *iommu, + struct device_node *np, unsigned long dbase, unsigned long dsize, + unsigned long fbase, unsigned long fsize) +{ + unsigned long base_pte, uaddr, ioaddr, *ptab; + + ptab = cell_iommu_alloc_ptab(iommu, fbase, fsize, dbase, dsize, 24); + + dma_iommu_fixed_base = fbase; + + pr_debug("iommu: mapping 0x%lx pages from 0x%lx\n", fsize, fbase); + + base_pte = CBE_IOPTE_PP_W | CBE_IOPTE_PP_R | CBE_IOPTE_M | + (cell_iommu_get_ioid(np) & CBE_IOPTE_IOID_Mask); + + if (iommu_fixed_is_weak) + pr_info("IOMMU: Using weak ordering for fixed mapping\n"); + else { + pr_info("IOMMU: Using strong ordering for fixed mapping\n"); + base_pte |= CBE_IOPTE_SO_RW; + } + + for (uaddr = 0; uaddr < fsize; uaddr += (1 << 24)) { + /* Don't touch the dynamic region */ + ioaddr = uaddr + fbase; + if (ioaddr >= dbase && ioaddr < (dbase + dsize)) { + pr_debug("iommu: fixed/dynamic overlap, skipping\n"); + continue; + } + + insert_16M_pte(uaddr, ptab, base_pte); + } + + mb(); +} + +static int __init cell_iommu_fixed_mapping_init(void) +{ + unsigned long dbase, dsize, fbase, fsize, hbase, hend; + struct cbe_iommu *iommu; + struct device_node *np; + + /* The fixed mapping is only supported on axon machines */ + np = of_find_node_by_name(NULL, "axon"); + of_node_put(np); + + if (!np) { + pr_debug("iommu: fixed mapping disabled, no axons found\n"); + return -1; + } + + /* We must have dma-ranges properties for fixed mapping to work */ + np = of_find_node_with_property(NULL, "dma-ranges"); + of_node_put(np); + + if (!np) { + pr_debug("iommu: no dma-ranges found, no fixed mapping\n"); + return -1; + } + + /* The default setup is to have the fixed mapping sit after the + * dynamic region, so find the top of the largest IOMMU window + * on any axon, then add the size of RAM and that's our max value. + * If that is > 32GB we have to do other shennanigans. + */ + fbase = 0; + for_each_node_by_name(np, "axon") { + cell_iommu_get_window(np, &dbase, &dsize); + fbase = max(fbase, dbase + dsize); + } + + fbase = ALIGN(fbase, 1 << IO_SEGMENT_SHIFT); + fsize = memblock_phys_mem_size(); + + if ((fbase + fsize) <= 0x800000000ul) + hbase = 0; /* use the device tree window */ + else { + /* If we're over 32 GB we need to cheat. We can't map all of + * RAM with the fixed mapping, and also fit the dynamic + * region. So try to place the dynamic region where the hash + * table sits, drivers never need to DMA to it, we don't + * need a fixed mapping for that area. + */ + if (!htab_address) { + pr_debug("iommu: htab is NULL, on LPAR? Huh?\n"); + return -1; + } + hbase = __pa(htab_address); + hend = hbase + htab_size_bytes; + + /* The window must start and end on a segment boundary */ + if ((hbase != ALIGN(hbase, 1 << IO_SEGMENT_SHIFT)) || + (hend != ALIGN(hend, 1 << IO_SEGMENT_SHIFT))) { + pr_debug("iommu: hash window not segment aligned\n"); + return -1; + } + + /* Check the hash window fits inside the real DMA window */ + for_each_node_by_name(np, "axon") { + cell_iommu_get_window(np, &dbase, &dsize); + + if (hbase < dbase || (hend > (dbase + dsize))) { + pr_debug("iommu: hash window doesn't fit in" + "real DMA window\n"); + of_node_put(np); + return -1; + } + } + + fbase = 0; + } + + /* Setup the dynamic regions */ + for_each_node_by_name(np, "axon") { + iommu = cell_iommu_alloc(np); + BUG_ON(!iommu); + + if (hbase == 0) + cell_iommu_get_window(np, &dbase, &dsize); + else { + dbase = hbase; + dsize = htab_size_bytes; + } + + printk(KERN_DEBUG "iommu: node %d, dynamic window 0x%lx-0x%lx " + "fixed window 0x%lx-0x%lx\n", iommu->nid, dbase, + dbase + dsize, fbase, fbase + fsize); + + cell_iommu_setup_stab(iommu, dbase, dsize, fbase, fsize); + iommu->ptab = cell_iommu_alloc_ptab(iommu, dbase, dsize, 0, 0, + IOMMU_PAGE_SHIFT_4K); + cell_iommu_setup_fixed_ptab(iommu, np, dbase, dsize, + fbase, fsize); + cell_iommu_enable_hardware(iommu); + cell_iommu_setup_window(iommu, np, dbase, dsize, 0); + } + + cell_pci_controller_ops.iommu_bypass_supported = + cell_pci_iommu_bypass_supported; + return 0; +} + +static int iommu_fixed_disabled; + +static int __init setup_iommu_fixed(char *str) +{ + struct device_node *pciep; + + if (strcmp(str, "off") == 0) + iommu_fixed_disabled = 1; + + /* If we can find a pcie-endpoint in the device tree assume that + * we're on a triblade or a CAB so by default the fixed mapping + * should be set to be weakly ordered; but only if the boot + * option WASN'T set for strong ordering + */ + pciep = of_find_node_by_type(NULL, "pcie-endpoint"); + + if (strcmp(str, "weak") == 0 || (pciep && strcmp(str, "strong") != 0)) + iommu_fixed_is_weak = true; + + of_node_put(pciep); + + return 1; +} +__setup("iommu_fixed=", setup_iommu_fixed); + +static int __init cell_iommu_init(void) +{ + struct device_node *np; + + /* If IOMMU is disabled or we have little enough RAM to not need + * to enable it, we setup a direct mapping. + * + * Note: should we make sure we have the IOMMU actually disabled ? + */ + if (iommu_is_off || + (!iommu_force_on && memblock_end_of_DRAM() <= 0x80000000ull)) + if (cell_iommu_init_disabled() == 0) + goto bail; + + /* Setup various callbacks */ + cell_pci_controller_ops.dma_dev_setup = cell_pci_dma_dev_setup; + + if (!iommu_fixed_disabled && cell_iommu_fixed_mapping_init() == 0) + goto done; + + /* Create an iommu for each /axon node. */ + for_each_node_by_name(np, "axon") { + if (np->parent == NULL || np->parent->parent != NULL) + continue; + cell_iommu_init_one(np, 0); + } + + /* Create an iommu for each toplevel /pci-internal node for + * old hardware/firmware + */ + for_each_node_by_name(np, "pci-internal") { + if (np->parent == NULL || np->parent->parent != NULL) + continue; + cell_iommu_init_one(np, SPIDER_DMA_OFFSET); + } + done: + /* Setup default PCI iommu ops */ + set_pci_dma_ops(&dma_iommu_ops); + cell_iommu_enabled = true; + bail: + /* Register callbacks on OF platform device addition/removal + * to handle linking them to the right DMA operations + */ + bus_register_notifier(&platform_bus_type, &cell_of_bus_notifier); + + return 0; +} +machine_arch_initcall(cell, cell_iommu_init); |