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ccio-dma.c
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ccio-dma.c
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// SPDX-License-Identifier: GPL-2.0-or-later
/*
** ccio-dma.c:
** DMA management routines for first generation cache-coherent machines.
** Program U2/Uturn in "Virtual Mode" and use the I/O MMU.
**
** (c) Copyright 2000 Grant Grundler
** (c) Copyright 2000 Ryan Bradetich
** (c) Copyright 2000 Hewlett-Packard Company
**
** "Real Mode" operation refers to U2/Uturn chip operation.
** U2/Uturn were designed to perform coherency checks w/o using
** the I/O MMU - basically what x86 does.
**
** Drawbacks of using Real Mode are:
** o outbound DMA is slower - U2 won't prefetch data (GSC+ XQL signal).
** o Inbound DMA less efficient - U2 can't use DMA_FAST attribute.
** o Ability to do scatter/gather in HW is lost.
** o Doesn't work under PCX-U/U+ machines since they didn't follow
** the coherency design originally worked out. Only PCX-W does.
*/
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/spinlock.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/pci.h>
#include <linux/reboot.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/dma-map-ops.h>
#include <linux/scatterlist.h>
#include <linux/iommu-helper.h>
#include <linux/export.h>
#include <asm/byteorder.h>
#include <asm/cache.h> /* for L1_CACHE_BYTES */
#include <linux/uaccess.h>
#include <asm/page.h>
#include <asm/dma.h>
#include <asm/io.h>
#include <asm/hardware.h> /* for register_module() */
#include <asm/parisc-device.h>
#include "iommu.h"
/*
** Choose "ccio" since that's what HP-UX calls it.
** Make it easier for folks to migrate from one to the other :^)
*/
#define MODULE_NAME "ccio"
#undef DEBUG_CCIO_RES
#undef DEBUG_CCIO_RUN
#undef DEBUG_CCIO_INIT
#undef DEBUG_CCIO_RUN_SG
#ifdef CONFIG_PROC_FS
/* depends on proc fs support. But costs CPU performance. */
#undef CCIO_COLLECT_STATS
#endif
#ifdef DEBUG_CCIO_INIT
#define DBG_INIT(x...) printk(x)
#else
#define DBG_INIT(x...)
#endif
#ifdef DEBUG_CCIO_RUN
#define DBG_RUN(x...) printk(x)
#else
#define DBG_RUN(x...)
#endif
#ifdef DEBUG_CCIO_RES
#define DBG_RES(x...) printk(x)
#else
#define DBG_RES(x...)
#endif
#ifdef DEBUG_CCIO_RUN_SG
#define DBG_RUN_SG(x...) printk(x)
#else
#define DBG_RUN_SG(x...)
#endif
#define WRITE_U32(value, addr) __raw_writel(value, addr)
#define READ_U32(addr) __raw_readl(addr)
#define U2_IOA_RUNWAY 0x580
#define U2_BC_GSC 0x501
#define UTURN_IOA_RUNWAY 0x581
#define UTURN_BC_GSC 0x502
#define IOA_NORMAL_MODE 0x00020080 /* IO_CONTROL to turn on CCIO */
#define CMD_TLB_DIRECT_WRITE 35 /* IO_COMMAND for I/O TLB Writes */
#define CMD_TLB_PURGE 33 /* IO_COMMAND to Purge I/O TLB entry */
struct ioa_registers {
/* Runway Supervisory Set */
int32_t unused1[12];
uint32_t io_command; /* Offset 12 */
uint32_t io_status; /* Offset 13 */
uint32_t io_control; /* Offset 14 */
int32_t unused2[1];
/* Runway Auxiliary Register Set */
uint32_t io_err_resp; /* Offset 0 */
uint32_t io_err_info; /* Offset 1 */
uint32_t io_err_req; /* Offset 2 */
uint32_t io_err_resp_hi; /* Offset 3 */
uint32_t io_tlb_entry_m; /* Offset 4 */
uint32_t io_tlb_entry_l; /* Offset 5 */
uint32_t unused3[1];
uint32_t io_pdir_base; /* Offset 7 */
uint32_t io_io_low_hv; /* Offset 8 */
uint32_t io_io_high_hv; /* Offset 9 */
uint32_t unused4[1];
uint32_t io_chain_id_mask; /* Offset 11 */
uint32_t unused5[2];
uint32_t io_io_low; /* Offset 14 */
uint32_t io_io_high; /* Offset 15 */
};
/*
** IOA Registers
** -------------
**
** Runway IO_CONTROL Register (+0x38)
**
** The Runway IO_CONTROL register controls the forwarding of transactions.
**
** | 0 ... 13 | 14 15 | 16 ... 21 | 22 | 23 24 | 25 ... 31 |
** | HV | TLB | reserved | HV | mode | reserved |
**
** o mode field indicates the address translation of transactions
** forwarded from Runway to GSC+:
** Mode Name Value Definition
** Off (default) 0 Opaque to matching addresses.
** Include 1 Transparent for matching addresses.
** Peek 3 Map matching addresses.
**
** + "Off" mode: Runway transactions which match the I/O range
** specified by the IO_IO_LOW/IO_IO_HIGH registers will be ignored.
** + "Include" mode: all addresses within the I/O range specified
** by the IO_IO_LOW and IO_IO_HIGH registers are transparently
** forwarded. This is the I/O Adapter's normal operating mode.
** + "Peek" mode: used during system configuration to initialize the
** GSC+ bus. Runway Write_Shorts in the address range specified by
** IO_IO_LOW and IO_IO_HIGH are forwarded through the I/O Adapter
** *AND* the GSC+ address is remapped to the Broadcast Physical
** Address space by setting the 14 high order address bits of the
** 32 bit GSC+ address to ones.
**
** o TLB field affects transactions which are forwarded from GSC+ to Runway.
** "Real" mode is the poweron default.
**
** TLB Mode Value Description
** Real 0 No TLB translation. Address is directly mapped and the
** virtual address is composed of selected physical bits.
** Error 1 Software fills the TLB manually.
** Normal 2 IOA fetches IO TLB misses from IO PDIR (in host memory).
**
**
** IO_IO_LOW_HV +0x60 (HV dependent)
** IO_IO_HIGH_HV +0x64 (HV dependent)
** IO_IO_LOW +0x78 (Architected register)
** IO_IO_HIGH +0x7c (Architected register)
**
** IO_IO_LOW and IO_IO_HIGH set the lower and upper bounds of the
** I/O Adapter address space, respectively.
**
** 0 ... 7 | 8 ... 15 | 16 ... 31 |
** 11111111 | 11111111 | address |
**
** Each LOW/HIGH pair describes a disjoint address space region.
** (2 per GSC+ port). Each incoming Runway transaction address is compared
** with both sets of LOW/HIGH registers. If the address is in the range
** greater than or equal to IO_IO_LOW and less than IO_IO_HIGH the transaction
** for forwarded to the respective GSC+ bus.
** Specify IO_IO_LOW equal to or greater than IO_IO_HIGH to avoid specifying
** an address space region.
**
** In order for a Runway address to reside within GSC+ extended address space:
** Runway Address [0:7] must identically compare to 8'b11111111
** Runway Address [8:11] must be equal to IO_IO_LOW(_HV)[16:19]
** Runway Address [12:23] must be greater than or equal to
** IO_IO_LOW(_HV)[20:31] and less than IO_IO_HIGH(_HV)[20:31].
** Runway Address [24:39] is not used in the comparison.
**
** When the Runway transaction is forwarded to GSC+, the GSC+ address is
** as follows:
** GSC+ Address[0:3] 4'b1111
** GSC+ Address[4:29] Runway Address[12:37]
** GSC+ Address[30:31] 2'b00
**
** All 4 Low/High registers must be initialized (by PDC) once the lower bus
** is interrogated and address space is defined. The operating system will
** modify the architectural IO_IO_LOW and IO_IO_HIGH registers following
** the PDC initialization. However, the hardware version dependent IO_IO_LOW
** and IO_IO_HIGH registers should not be subsequently altered by the OS.
**
** Writes to both sets of registers will take effect immediately, bypassing
** the queues, which ensures that subsequent Runway transactions are checked
** against the updated bounds values. However reads are queued, introducing
** the possibility of a read being bypassed by a subsequent write to the same
** register. This sequence can be avoided by having software wait for read
** returns before issuing subsequent writes.
*/
struct ioc {
struct ioa_registers __iomem *ioc_regs; /* I/O MMU base address */
u8 *res_map; /* resource map, bit == pdir entry */
__le64 *pdir_base; /* physical base address */
u32 pdir_size; /* bytes, function of IOV Space size */
u32 res_hint; /* next available IOVP -
circular search */
u32 res_size; /* size of resource map in bytes */
spinlock_t res_lock;
#ifdef CCIO_COLLECT_STATS
#define CCIO_SEARCH_SAMPLE 0x100
unsigned long avg_search[CCIO_SEARCH_SAMPLE];
unsigned long avg_idx; /* current index into avg_search */
unsigned long used_pages;
unsigned long msingle_calls;
unsigned long msingle_pages;
unsigned long msg_calls;
unsigned long msg_pages;
unsigned long usingle_calls;
unsigned long usingle_pages;
unsigned long usg_calls;
unsigned long usg_pages;
#endif
unsigned short cujo20_bug;
/* STUFF We don't need in performance path */
u32 chainid_shift; /* specify bit location of chain_id */
struct ioc *next; /* Linked list of discovered iocs */
const char *name; /* device name from firmware */
unsigned int hw_path; /* the hardware path this ioc is associatd with */
struct pci_dev *fake_pci_dev; /* the fake pci_dev for non-pci devs */
struct resource mmio_region[2]; /* The "routed" MMIO regions */
};
static struct ioc *ioc_list;
static int ioc_count;
/**************************************************************
*
* I/O Pdir Resource Management
*
* Bits set in the resource map are in use.
* Each bit can represent a number of pages.
* LSbs represent lower addresses (IOVA's).
*
* This was copied from sba_iommu.c. Don't try to unify
* the two resource managers unless a way to have different
* allocation policies is also adjusted. We'd like to avoid
* I/O TLB thrashing by having resource allocation policy
* match the I/O TLB replacement policy.
*
***************************************************************/
#define IOVP_SIZE PAGE_SIZE
#define IOVP_SHIFT PAGE_SHIFT
#define IOVP_MASK PAGE_MASK
/* Convert from IOVP to IOVA and vice versa. */
#define CCIO_IOVA(iovp,offset) ((iovp) | (offset))
#define CCIO_IOVP(iova) ((iova) & IOVP_MASK)
#define PDIR_INDEX(iovp) ((iovp)>>IOVP_SHIFT)
#define MKIOVP(pdir_idx) ((long)(pdir_idx) << IOVP_SHIFT)
#define MKIOVA(iovp,offset) (dma_addr_t)((long)iovp | (long)offset)
/*
** Don't worry about the 150% average search length on a miss.
** If the search wraps around, and passes the res_hint, it will
** cause the kernel to panic anyhow.
*/
#define CCIO_SEARCH_LOOP(ioc, res_idx, mask, size) \
for (; res_ptr < res_end; ++res_ptr) { \
int ret;\
unsigned int idx;\
idx = (unsigned int)((unsigned long)res_ptr - (unsigned long)ioc->res_map); \
ret = iommu_is_span_boundary(idx << 3, pages_needed, 0, boundary_size);\
if ((0 == (*res_ptr & mask)) && !ret) { \
*res_ptr |= mask; \
res_idx = idx;\
ioc->res_hint = res_idx + (size >> 3); \
goto resource_found; \
} \
}
#define CCIO_FIND_FREE_MAPPING(ioa, res_idx, mask, size) \
u##size *res_ptr = (u##size *)&((ioc)->res_map[ioa->res_hint & ~((size >> 3) - 1)]); \
u##size *res_end = (u##size *)&(ioc)->res_map[ioa->res_size]; \
CCIO_SEARCH_LOOP(ioc, res_idx, mask, size); \
res_ptr = (u##size *)&(ioc)->res_map[0]; \
CCIO_SEARCH_LOOP(ioa, res_idx, mask, size);
/*
** Find available bit in this ioa's resource map.
** Use a "circular" search:
** o Most IOVA's are "temporary" - avg search time should be small.
** o keep a history of what happened for debugging
** o KISS.
**
** Perf optimizations:
** o search for log2(size) bits at a time.
** o search for available resource bits using byte/word/whatever.
** o use different search for "large" (eg > 4 pages) or "very large"
** (eg > 16 pages) mappings.
*/
/**
* ccio_alloc_range - Allocate pages in the ioc's resource map.
* @ioc: The I/O Controller.
* @dev: The PCI device.
* @size: The requested number of bytes to be mapped into the
* I/O Pdir...
*
* This function searches the resource map of the ioc to locate a range
* of available pages for the requested size.
*/
static int
ccio_alloc_range(struct ioc *ioc, struct device *dev, size_t size)
{
unsigned int pages_needed = size >> IOVP_SHIFT;
unsigned int res_idx;
unsigned long boundary_size;
#ifdef CCIO_COLLECT_STATS
unsigned long cr_start = mfctl(16);
#endif
BUG_ON(pages_needed == 0);
BUG_ON((pages_needed * IOVP_SIZE) > DMA_CHUNK_SIZE);
DBG_RES("%s() size: %zu pages_needed %d\n",
__func__, size, pages_needed);
/*
** "seek and ye shall find"...praying never hurts either...
** ggg sacrifices another 710 to the computer gods.
*/
boundary_size = dma_get_seg_boundary_nr_pages(dev, IOVP_SHIFT);
if (pages_needed <= 8) {
/*
* LAN traffic will not thrash the TLB IFF the same NIC
* uses 8 adjacent pages to map separate payload data.
* ie the same byte in the resource bit map.
*/
#if 0
/* FIXME: bit search should shift it's way through
* an unsigned long - not byte at a time. As it is now,
* we effectively allocate this byte to this mapping.
*/
unsigned long mask = ~(~0UL >> pages_needed);
CCIO_FIND_FREE_MAPPING(ioc, res_idx, mask, 8);
#else
CCIO_FIND_FREE_MAPPING(ioc, res_idx, 0xff, 8);
#endif
} else if (pages_needed <= 16) {
CCIO_FIND_FREE_MAPPING(ioc, res_idx, 0xffff, 16);
} else if (pages_needed <= 32) {
CCIO_FIND_FREE_MAPPING(ioc, res_idx, ~(unsigned int)0, 32);
#ifdef __LP64__
} else if (pages_needed <= 64) {
CCIO_FIND_FREE_MAPPING(ioc, res_idx, ~0UL, 64);
#endif
} else {
panic("%s: %s() Too many pages to map. pages_needed: %u\n",
__FILE__, __func__, pages_needed);
}
panic("%s: %s() I/O MMU is out of mapping resources.\n", __FILE__,
__func__);
resource_found:
DBG_RES("%s() res_idx %d res_hint: %d\n",
__func__, res_idx, ioc->res_hint);
#ifdef CCIO_COLLECT_STATS
{
unsigned long cr_end = mfctl(16);
unsigned long tmp = cr_end - cr_start;
/* check for roll over */
cr_start = (cr_end < cr_start) ? -(tmp) : (tmp);
}
ioc->avg_search[ioc->avg_idx++] = cr_start;
ioc->avg_idx &= CCIO_SEARCH_SAMPLE - 1;
ioc->used_pages += pages_needed;
#endif
/*
** return the bit address.
*/
return res_idx << 3;
}
#define CCIO_FREE_MAPPINGS(ioc, res_idx, mask, size) \
u##size *res_ptr = (u##size *)&((ioc)->res_map[res_idx]); \
BUG_ON((*res_ptr & mask) != mask); \
*res_ptr &= ~(mask);
/**
* ccio_free_range - Free pages from the ioc's resource map.
* @ioc: The I/O Controller.
* @iova: The I/O Virtual Address.
* @pages_mapped: The requested number of pages to be freed from the
* I/O Pdir.
*
* This function frees the resouces allocated for the iova.
*/
static void
ccio_free_range(struct ioc *ioc, dma_addr_t iova, unsigned long pages_mapped)
{
unsigned long iovp = CCIO_IOVP(iova);
unsigned int res_idx = PDIR_INDEX(iovp) >> 3;
BUG_ON(pages_mapped == 0);
BUG_ON((pages_mapped * IOVP_SIZE) > DMA_CHUNK_SIZE);
BUG_ON(pages_mapped > BITS_PER_LONG);
DBG_RES("%s(): res_idx: %d pages_mapped %lu\n",
__func__, res_idx, pages_mapped);
#ifdef CCIO_COLLECT_STATS
ioc->used_pages -= pages_mapped;
#endif
if(pages_mapped <= 8) {
#if 0
/* see matching comments in alloc_range */
unsigned long mask = ~(~0UL >> pages_mapped);
CCIO_FREE_MAPPINGS(ioc, res_idx, mask, 8);
#else
CCIO_FREE_MAPPINGS(ioc, res_idx, 0xffUL, 8);
#endif
} else if(pages_mapped <= 16) {
CCIO_FREE_MAPPINGS(ioc, res_idx, 0xffffUL, 16);
} else if(pages_mapped <= 32) {
CCIO_FREE_MAPPINGS(ioc, res_idx, ~(unsigned int)0, 32);
#ifdef __LP64__
} else if(pages_mapped <= 64) {
CCIO_FREE_MAPPINGS(ioc, res_idx, ~0UL, 64);
#endif
} else {
panic("%s:%s() Too many pages to unmap.\n", __FILE__,
__func__);
}
}
/****************************************************************
**
** CCIO dma_ops support routines
**
*****************************************************************/
typedef unsigned long space_t;
#define KERNEL_SPACE 0
/*
** DMA "Page Type" and Hints
** o if SAFE_DMA isn't set, mapping is for FAST_DMA. SAFE_DMA should be
** set for subcacheline DMA transfers since we don't want to damage the
** other part of a cacheline.
** o SAFE_DMA must be set for "memory" allocated via pci_alloc_consistent().
** This bit tells U2 to do R/M/W for partial cachelines. "Streaming"
** data can avoid this if the mapping covers full cache lines.
** o STOP_MOST is needed for atomicity across cachelines.
** Apparently only "some EISA devices" need this.
** Using CONFIG_ISA is hack. Only the IOA with EISA under it needs
** to use this hint iff the EISA devices needs this feature.
** According to the U2 ERS, STOP_MOST enabled pages hurt performance.
** o PREFETCH should *not* be set for cases like Multiple PCI devices
** behind GSCtoPCI (dino) bus converter. Only one cacheline per GSC
** device can be fetched and multiply DMA streams will thrash the
** prefetch buffer and burn memory bandwidth. See 6.7.3 "Prefetch Rules
** and Invalidation of Prefetch Entries".
**
** FIXME: the default hints need to be per GSC device - not global.
**
** HP-UX dorks: linux device driver programming model is totally different
** than HP-UX's. HP-UX always sets HINT_PREFETCH since it's drivers
** do special things to work on non-coherent platforms...linux has to
** be much more careful with this.
*/
#define IOPDIR_VALID 0x01UL
#define HINT_SAFE_DMA 0x02UL /* used for pci_alloc_consistent() pages */
#ifdef CONFIG_EISA
#define HINT_STOP_MOST 0x04UL /* LSL support */
#else
#define HINT_STOP_MOST 0x00UL /* only needed for "some EISA devices" */
#endif
#define HINT_UDPATE_ENB 0x08UL /* not used/supported by U2 */
#define HINT_PREFETCH 0x10UL /* for outbound pages which are not SAFE */
/*
** Use direction (ie PCI_DMA_TODEVICE) to pick hint.
** ccio_alloc_consistent() depends on this to get SAFE_DMA
** when it passes in BIDIRECTIONAL flag.
*/
static u32 hint_lookup[] = {
[DMA_BIDIRECTIONAL] = HINT_STOP_MOST | HINT_SAFE_DMA | IOPDIR_VALID,
[DMA_TO_DEVICE] = HINT_STOP_MOST | HINT_PREFETCH | IOPDIR_VALID,
[DMA_FROM_DEVICE] = HINT_STOP_MOST | IOPDIR_VALID,
};
/**
* ccio_io_pdir_entry - Initialize an I/O Pdir.
* @pdir_ptr: A pointer into I/O Pdir.
* @sid: The Space Identifier.
* @vba: The virtual address.
* @hints: The DMA Hint.
*
* Given a virtual address (vba, arg2) and space id, (sid, arg1),
* load the I/O PDIR entry pointed to by pdir_ptr (arg0). Each IO Pdir
* entry consists of 8 bytes as shown below (MSB == bit 0):
*
*
* WORD 0:
* +------+----------------+-----------------------------------------------+
* | Phys | Virtual Index | Phys |
* | 0:3 | 0:11 | 4:19 |
* |4 bits| 12 bits | 16 bits |
* +------+----------------+-----------------------------------------------+
* WORD 1:
* +-----------------------+-----------------------------------------------+
* | Phys | Rsvd | Prefetch |Update |Rsvd |Lock |Safe |Valid |
* | 20:39 | | Enable |Enable | |Enable|DMA | |
* | 20 bits | 5 bits | 1 bit |1 bit |2 bits|1 bit |1 bit |1 bit |
* +-----------------------+-----------------------------------------------+
*
* The virtual index field is filled with the results of the LCI
* (Load Coherence Index) instruction. The 8 bits used for the virtual
* index are bits 12:19 of the value returned by LCI.
*/
static void
ccio_io_pdir_entry(__le64 *pdir_ptr, space_t sid, unsigned long vba,
unsigned long hints)
{
register unsigned long pa;
register unsigned long ci; /* coherent index */
/* We currently only support kernel addresses */
BUG_ON(sid != KERNEL_SPACE);
/*
** WORD 1 - low order word
** "hints" parm includes the VALID bit!
** "dep" clobbers the physical address offset bits as well.
*/
pa = lpa(vba);
asm volatile("depw %1,31,12,%0" : "+r" (pa) : "r" (hints));
((u32 *)pdir_ptr)[1] = (u32) pa;
/*
** WORD 0 - high order word
*/
#ifdef __LP64__
/*
** get bits 12:15 of physical address
** shift bits 16:31 of physical address
** and deposit them
*/
asm volatile ("extrd,u %1,15,4,%0" : "=r" (ci) : "r" (pa));
asm volatile ("extrd,u %1,31,16,%0" : "+r" (pa) : "r" (pa));
asm volatile ("depd %1,35,4,%0" : "+r" (pa) : "r" (ci));
#else
pa = 0;
#endif
/*
** get CPU coherency index bits
** Grab virtual index [0:11]
** Deposit virt_idx bits into I/O PDIR word
*/
asm volatile ("lci %%r0(%1), %0" : "=r" (ci) : "r" (vba));
asm volatile ("extru %1,19,12,%0" : "+r" (ci) : "r" (ci));
asm volatile ("depw %1,15,12,%0" : "+r" (pa) : "r" (ci));
((u32 *)pdir_ptr)[0] = (u32) pa;
/* FIXME: PCX_W platforms don't need FDC/SYNC. (eg C360)
** PCX-U/U+ do. (eg C200/C240)
** PCX-T'? Don't know. (eg C110 or similar K-class)
**
** See PDC_MODEL/option 0/SW_CAP word for "Non-coherent IO-PDIR bit".
**
** "Since PCX-U employs an offset hash that is incompatible with
** the real mode coherence index generation of U2, the PDIR entry
** must be flushed to memory to retain coherence."
*/
asm_io_fdc(pdir_ptr);
asm_io_sync();
}
/**
* ccio_clear_io_tlb - Remove stale entries from the I/O TLB.
* @ioc: The I/O Controller.
* @iovp: The I/O Virtual Page.
* @byte_cnt: The requested number of bytes to be freed from the I/O Pdir.
*
* Purge invalid I/O PDIR entries from the I/O TLB.
*
* FIXME: Can we change the byte_cnt to pages_mapped?
*/
static void
ccio_clear_io_tlb(struct ioc *ioc, dma_addr_t iovp, size_t byte_cnt)
{
u32 chain_size = 1 << ioc->chainid_shift;
iovp &= IOVP_MASK; /* clear offset bits, just want pagenum */
byte_cnt += chain_size;
while(byte_cnt > chain_size) {
WRITE_U32(CMD_TLB_PURGE | iovp, &ioc->ioc_regs->io_command);
iovp += chain_size;
byte_cnt -= chain_size;
}
}
/**
* ccio_mark_invalid - Mark the I/O Pdir entries invalid.
* @ioc: The I/O Controller.
* @iova: The I/O Virtual Address.
* @byte_cnt: The requested number of bytes to be freed from the I/O Pdir.
*
* Mark the I/O Pdir entries invalid and blow away the corresponding I/O
* TLB entries.
*
* FIXME: at some threshold it might be "cheaper" to just blow
* away the entire I/O TLB instead of individual entries.
*
* FIXME: Uturn has 256 TLB entries. We don't need to purge every
* PDIR entry - just once for each possible TLB entry.
* (We do need to maker I/O PDIR entries invalid regardless).
*
* FIXME: Can we change byte_cnt to pages_mapped?
*/
static void
ccio_mark_invalid(struct ioc *ioc, dma_addr_t iova, size_t byte_cnt)
{
u32 iovp = (u32)CCIO_IOVP(iova);
size_t saved_byte_cnt;
/* round up to nearest page size */
saved_byte_cnt = byte_cnt = ALIGN(byte_cnt, IOVP_SIZE);
while(byte_cnt > 0) {
/* invalidate one page at a time */
unsigned int idx = PDIR_INDEX(iovp);
char *pdir_ptr = (char *) &(ioc->pdir_base[idx]);
BUG_ON(idx >= (ioc->pdir_size / sizeof(u64)));
pdir_ptr[7] = 0; /* clear only VALID bit */
/*
** FIXME: PCX_W platforms don't need FDC/SYNC. (eg C360)
** PCX-U/U+ do. (eg C200/C240)
** See PDC_MODEL/option 0/SW_CAP for "Non-coherent IO-PDIR bit".
*/
asm_io_fdc(pdir_ptr);
iovp += IOVP_SIZE;
byte_cnt -= IOVP_SIZE;
}
asm_io_sync();
ccio_clear_io_tlb(ioc, CCIO_IOVP(iova), saved_byte_cnt);
}
/****************************************************************
**
** CCIO dma_ops
**
*****************************************************************/
/**
* ccio_dma_supported - Verify the IOMMU supports the DMA address range.
* @dev: The PCI device.
* @mask: A bit mask describing the DMA address range of the device.
*/
static int
ccio_dma_supported(struct device *dev, u64 mask)
{
if(dev == NULL) {
printk(KERN_ERR MODULE_NAME ": EISA/ISA/et al not supported\n");
BUG();
return 0;
}
/* only support 32-bit or better devices (ie PCI/GSC) */
return (int)(mask >= 0xffffffffUL);
}
/**
* ccio_map_single - Map an address range into the IOMMU.
* @dev: The PCI device.
* @addr: The start address of the DMA region.
* @size: The length of the DMA region.
* @direction: The direction of the DMA transaction (to/from device).
*
* This function implements the pci_map_single function.
*/
static dma_addr_t
ccio_map_single(struct device *dev, void *addr, size_t size,
enum dma_data_direction direction)
{
int idx;
struct ioc *ioc;
unsigned long flags;
dma_addr_t iovp;
dma_addr_t offset;
__le64 *pdir_start;
unsigned long hint = hint_lookup[(int)direction];
BUG_ON(!dev);
ioc = GET_IOC(dev);
if (!ioc)
return DMA_MAPPING_ERROR;
BUG_ON(size <= 0);
/* save offset bits */
offset = ((unsigned long) addr) & ~IOVP_MASK;
/* round up to nearest IOVP_SIZE */
size = ALIGN(size + offset, IOVP_SIZE);
spin_lock_irqsave(&ioc->res_lock, flags);
#ifdef CCIO_COLLECT_STATS
ioc->msingle_calls++;
ioc->msingle_pages += size >> IOVP_SHIFT;
#endif
idx = ccio_alloc_range(ioc, dev, size);
iovp = (dma_addr_t)MKIOVP(idx);
pdir_start = &(ioc->pdir_base[idx]);
DBG_RUN("%s() %px -> %#lx size: %zu\n",
__func__, addr, (long)(iovp | offset), size);
/* If not cacheline aligned, force SAFE_DMA on the whole mess */
if((size % L1_CACHE_BYTES) || ((unsigned long)addr % L1_CACHE_BYTES))
hint |= HINT_SAFE_DMA;
while(size > 0) {
ccio_io_pdir_entry(pdir_start, KERNEL_SPACE, (unsigned long)addr, hint);
DBG_RUN(" pdir %p %08x%08x\n",
pdir_start,
(u32) (((u32 *) pdir_start)[0]),
(u32) (((u32 *) pdir_start)[1]));
++pdir_start;
addr += IOVP_SIZE;
size -= IOVP_SIZE;
}
spin_unlock_irqrestore(&ioc->res_lock, flags);
/* form complete address */
return CCIO_IOVA(iovp, offset);
}
static dma_addr_t
ccio_map_page(struct device *dev, struct page *page, unsigned long offset,
size_t size, enum dma_data_direction direction,
unsigned long attrs)
{
return ccio_map_single(dev, page_address(page) + offset, size,
direction);
}
/**
* ccio_unmap_page - Unmap an address range from the IOMMU.
* @dev: The PCI device.
* @iova: The start address of the DMA region.
* @size: The length of the DMA region.
* @direction: The direction of the DMA transaction (to/from device).
* @attrs: attributes
*/
static void
ccio_unmap_page(struct device *dev, dma_addr_t iova, size_t size,
enum dma_data_direction direction, unsigned long attrs)
{
struct ioc *ioc;
unsigned long flags;
dma_addr_t offset = iova & ~IOVP_MASK;
BUG_ON(!dev);
ioc = GET_IOC(dev);
if (!ioc) {
WARN_ON(!ioc);
return;
}
DBG_RUN("%s() iovp %#lx/%zx\n",
__func__, (long)iova, size);
iova ^= offset; /* clear offset bits */
size += offset;
size = ALIGN(size, IOVP_SIZE);
spin_lock_irqsave(&ioc->res_lock, flags);
#ifdef CCIO_COLLECT_STATS
ioc->usingle_calls++;
ioc->usingle_pages += size >> IOVP_SHIFT;
#endif
ccio_mark_invalid(ioc, iova, size);
ccio_free_range(ioc, iova, (size >> IOVP_SHIFT));
spin_unlock_irqrestore(&ioc->res_lock, flags);
}
/**
* ccio_alloc - Allocate a consistent DMA mapping.
* @dev: The PCI device.
* @size: The length of the DMA region.
* @dma_handle: The DMA address handed back to the device (not the cpu).
* @flag: allocation flags
* @attrs: attributes
*
* This function implements the pci_alloc_consistent function.
*/
static void *
ccio_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle, gfp_t flag,
unsigned long attrs)
{
void *ret;
#if 0
/* GRANT Need to establish hierarchy for non-PCI devs as well
** and then provide matching gsc_map_xxx() functions for them as well.
*/
if(!hwdev) {
/* only support PCI */
*dma_handle = 0;
return 0;
}
#endif
ret = (void *) __get_free_pages(flag, get_order(size));
if (ret) {
memset(ret, 0, size);
*dma_handle = ccio_map_single(dev, ret, size, DMA_BIDIRECTIONAL);
}
return ret;
}
/**
* ccio_free - Free a consistent DMA mapping.
* @dev: The PCI device.
* @size: The length of the DMA region.
* @cpu_addr: The cpu address returned from the ccio_alloc_consistent.
* @dma_handle: The device address returned from the ccio_alloc_consistent.
* @attrs: attributes
*
* This function implements the pci_free_consistent function.
*/
static void
ccio_free(struct device *dev, size_t size, void *cpu_addr,
dma_addr_t dma_handle, unsigned long attrs)
{
ccio_unmap_page(dev, dma_handle, size, 0, 0);
free_pages((unsigned long)cpu_addr, get_order(size));
}
/*
** Since 0 is a valid pdir_base index value, can't use that
** to determine if a value is valid or not. Use a flag to indicate
** the SG list entry contains a valid pdir index.
*/
#define PIDE_FLAG 0x80000000UL
#ifdef CCIO_COLLECT_STATS
#define IOMMU_MAP_STATS
#endif
#include "iommu-helpers.h"
/**
* ccio_map_sg - Map the scatter/gather list into the IOMMU.
* @dev: The PCI device.
* @sglist: The scatter/gather list to be mapped in the IOMMU.
* @nents: The number of entries in the scatter/gather list.
* @direction: The direction of the DMA transaction (to/from device).
* @attrs: attributes
*
* This function implements the pci_map_sg function.
*/
static int
ccio_map_sg(struct device *dev, struct scatterlist *sglist, int nents,
enum dma_data_direction direction, unsigned long attrs)
{
struct ioc *ioc;
int coalesced, filled = 0;
unsigned long flags;
unsigned long hint = hint_lookup[(int)direction];
unsigned long prev_len = 0, current_len = 0;
int i;
BUG_ON(!dev);
ioc = GET_IOC(dev);
if (!ioc)
return -EINVAL;
DBG_RUN_SG("%s() START %d entries\n", __func__, nents);
/* Fast path single entry scatterlists. */
if (nents == 1) {
sg_dma_address(sglist) = ccio_map_single(dev,
sg_virt(sglist), sglist->length,
direction);
sg_dma_len(sglist) = sglist->length;
return 1;
}
for(i = 0; i < nents; i++)
prev_len += sglist[i].length;
spin_lock_irqsave(&ioc->res_lock, flags);
#ifdef CCIO_COLLECT_STATS
ioc->msg_calls++;
#endif
/*
** First coalesce the chunks and allocate I/O pdir space
**
** If this is one DMA stream, we can properly map using the
** correct virtual address associated with each DMA page.
** w/o this association, we wouldn't have coherent DMA!
** Access to the virtual address is what forces a two pass algorithm.
*/
coalesced = iommu_coalesce_chunks(ioc, dev, sglist, nents, ccio_alloc_range);
/*
** Program the I/O Pdir
**
** map the virtual addresses to the I/O Pdir
** o dma_address will contain the pdir index
** o dma_len will contain the number of bytes to map
** o page/offset contain the virtual address.
*/
filled = iommu_fill_pdir(ioc, sglist, nents, hint, ccio_io_pdir_entry);
spin_unlock_irqrestore(&ioc->res_lock, flags);
BUG_ON(coalesced != filled);
DBG_RUN_SG("%s() DONE %d mappings\n", __func__, filled);
for (i = 0; i < filled; i++)
current_len += sg_dma_len(sglist + i);
BUG_ON(current_len != prev_len);
return filled;
}
/**
* ccio_unmap_sg - Unmap the scatter/gather list from the IOMMU.
* @dev: The PCI device.
* @sglist: The scatter/gather list to be unmapped from the IOMMU.
* @nents: The number of entries in the scatter/gather list.
* @direction: The direction of the DMA transaction (to/from device).
* @attrs: attributes
*
* This function implements the pci_unmap_sg function.
*/
static void
ccio_unmap_sg(struct device *dev, struct scatterlist *sglist, int nents,
enum dma_data_direction direction, unsigned long attrs)
{
struct ioc *ioc;
BUG_ON(!dev);
ioc = GET_IOC(dev);
if (!ioc) {
WARN_ON(!ioc);
return;
}
DBG_RUN_SG("%s() START %d entries, %p,%x\n",
__func__, nents, sg_virt(sglist), sglist->length);
#ifdef CCIO_COLLECT_STATS
ioc->usg_calls++;
#endif