[PATCH 4/4] swiotlb abstraction (e.g. for Xen)
From: Jan Beulich
Date: Tue Jan 02 2007 - 11:20:39 EST
This patch adds abstraction so that the file can be used by environments other
than IA64 and EM64T, namely for Xen.
Even if this patch is considered too convoluted, I would appreciate if the
other three ones could still be considered for merging.
Signed-off-by: Jan Beulich <jbeulich@xxxxxxxxxx>
Index: 2.6.20-rc3-swiotlb-bugs/include/asm-ia64/swiotlb.h
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ 2.6.20-rc3-swiotlb-bugs/include/asm-ia64/swiotlb.h 2007-01-02 16:55:32.000000000 +0100
@@ -0,0 +1,9 @@
+#ifndef _ASM_SWIOTLB_H
+#define _ASM_SWIOTLB_H 1
+
+#include <asm/machvec.h>
+
+#define SWIOTLB_ARCH_NEED_LATE_INIT
+#define SWIOTLB_ARCH_NEED_ALLOC
+
+#endif /* _ASM_SWIOTLB_H */
Index: 2.6.20-rc3-swiotlb-bugs/include/asm-x86_64/swiotlb.h
===================================================================
--- 2.6.20-rc3-swiotlb-bugs.orig/include/asm-x86_64/swiotlb.h 2007-01-02 16:12:20.000000000 +0100
+++ 2.6.20-rc3-swiotlb-bugs/include/asm-x86_64/swiotlb.h 2007-01-02 16:55:32.000000000 +0100
@@ -44,6 +44,7 @@ extern void swiotlb_init(void);
extern int swiotlb_force;
#ifdef CONFIG_SWIOTLB
+#define SWIOTLB_ARCH_NEED_ALLOC
extern int swiotlb;
#else
#define swiotlb 0
Index: 2.6.20-rc3-swiotlb-bugs/lib/swiotlb.c
===================================================================
--- 2.6.20-rc3-swiotlb-bugs.orig/lib/swiotlb.c 2007-01-02 16:52:51.000000000 +0100
+++ 2.6.20-rc3-swiotlb-bugs/lib/swiotlb.c 2007-01-02 17:04:38.000000000 +0100
@@ -28,6 +28,7 @@
#include <asm/io.h>
#include <asm/dma.h>
#include <asm/scatterlist.h>
+#include <asm/swiotlb.h>
#include <linux/init.h>
#include <linux/bootmem.h>
@@ -35,8 +36,10 @@
#define OFFSET(val,align) ((unsigned long) \
( (val) & ( (align) - 1)))
+#ifndef SG_ENT_VIRT_ADDRESS
#define SG_ENT_VIRT_ADDRESS(sg) (page_address((sg)->page) + (sg)->offset)
#define SG_ENT_PHYS_ADDRESS(sg) virt_to_bus(SG_ENT_VIRT_ADDRESS(sg))
+#endif
/*
* Maximum allowable number of contiguous slabs to map,
@@ -101,13 +104,25 @@ static unsigned int io_tlb_index;
* We need to save away the original address corresponding to a mapped entry
* for the sync operations.
*/
-static unsigned char **io_tlb_orig_addr;
+#ifndef SWIOTLB_ARCH_HAS_IO_TLB_ADDR_T
+typedef char *io_tlb_addr_t;
+#define swiotlb_orig_addr_null(buffer) (!(buffer))
+#define ptr_to_io_tlb_addr(ptr) (ptr)
+#define page_to_io_tlb_addr(pg, off) (page_address(pg) + (off))
+#define sg_to_io_tlb_addr(sg) SG_ENT_VIRT_ADDRESS(sg)
+#endif
+static io_tlb_addr_t *io_tlb_orig_addr;
/*
* Protect the above data structures in the map and unmap calls
*/
static DEFINE_SPINLOCK(io_tlb_lock);
+#ifdef SWIOTLB_EXTRA_VARIABLES
+SWIOTLB_EXTRA_VARIABLES;
+#endif
+
+#ifndef SWIOTLB_ARCH_HAS_SETUP_IO_TLB_NPAGES
static int __init
setup_io_tlb_npages(char *str)
{
@@ -122,9 +137,25 @@ setup_io_tlb_npages(char *str)
swiotlb_force = 1;
return 1;
}
+#endif
__setup("swiotlb=", setup_io_tlb_npages);
/* make io_tlb_overflow tunable too? */
+#ifndef swiotlb_adjust_size
+#define swiotlb_adjust_size(size) ((void)0)
+#endif
+
+#ifndef swiotlb_adjust_seg
+#define swiotlb_adjust_seg(start, size) ((void)0)
+#endif
+
+#ifndef swiotlb_print_info
+#define swiotlb_print_info(bytes) \
+ printk(KERN_INFO "Placing %luMB software IO TLB between 0x%lx - " \
+ "0x%lx\n", bytes >> 20, \
+ virt_to_bus(io_tlb_start), virt_to_bus(io_tlb_end))
+#endif
+
/*
* Statically reserve bounce buffer space and initialize bounce buffer data
* structures for the software IO TLB used to implement the DMA API.
@@ -138,6 +169,8 @@ swiotlb_init_with_default_size(size_t de
io_tlb_nslabs = (default_size >> IO_TLB_SHIFT);
io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE);
}
+ swiotlb_adjust_size(io_tlb_nslabs);
+ swiotlb_adjust_size(io_tlb_overflow);
bytes = io_tlb_nslabs << IO_TLB_SHIFT;
@@ -155,10 +188,14 @@ swiotlb_init_with_default_size(size_t de
* between io_tlb_start and io_tlb_end.
*/
io_tlb_list = alloc_bootmem(io_tlb_nslabs * sizeof(int));
- for (i = 0; i < io_tlb_nslabs; i++)
+ for (i = 0; i < io_tlb_nslabs; i++) {
+ if ( !(i % IO_TLB_SEGSIZE) )
+ swiotlb_adjust_seg(io_tlb_start + (i << IO_TLB_SHIFT),
+ IO_TLB_SEGSIZE << IO_TLB_SHIFT);
io_tlb_list[i] = IO_TLB_SEGSIZE - OFFSET(i, IO_TLB_SEGSIZE);
+ }
io_tlb_index = 0;
- io_tlb_orig_addr = alloc_bootmem(io_tlb_nslabs * sizeof(char *));
+ io_tlb_orig_addr = alloc_bootmem(io_tlb_nslabs * sizeof(io_tlb_addr_t));
/*
* Get the overflow emergency buffer
@@ -166,17 +203,21 @@ swiotlb_init_with_default_size(size_t de
io_tlb_overflow_buffer = alloc_bootmem_low(io_tlb_overflow);
if (!io_tlb_overflow_buffer)
panic("Cannot allocate SWIOTLB overflow buffer!\n");
+ swiotlb_adjust_seg(io_tlb_overflow_buffer, io_tlb_overflow);
- printk(KERN_INFO "Placing software IO TLB between 0x%lx - 0x%lx\n",
- virt_to_bus(io_tlb_start), virt_to_bus(io_tlb_end));
+ swiotlb_print_info(bytes);
}
+#ifndef __swiotlb_init_with_default_size
+#define __swiotlb_init_with_default_size swiotlb_init_with_default_size
+#endif
void __init
swiotlb_init(void)
{
- swiotlb_init_with_default_size(64 * (1<<20)); /* default to 64MB */
+ __swiotlb_init_with_default_size(64 * (1<<20)); /* default to 64MB */
}
+#ifdef SWIOTLB_ARCH_NEED_LATE_INIT
/*
* Systems with larger DMA zones (those that don't support ISA) can
* initialize the swiotlb later using the slab allocator if needed.
@@ -234,12 +275,12 @@ swiotlb_late_init_with_default_size(size
io_tlb_list[i] = IO_TLB_SEGSIZE - OFFSET(i, IO_TLB_SEGSIZE);
io_tlb_index = 0;
- io_tlb_orig_addr = (unsigned char **)__get_free_pages(GFP_KERNEL,
- get_order(io_tlb_nslabs * sizeof(char *)));
+ io_tlb_orig_addr = (io_tlb_addr_t *)__get_free_pages(GFP_KERNEL,
+ get_order(io_tlb_nslabs * sizeof(io_tlb_addr_t)));
if (!io_tlb_orig_addr)
goto cleanup3;
- memset(io_tlb_orig_addr, 0, io_tlb_nslabs * sizeof(char *));
+ memset(io_tlb_orig_addr, 0, io_tlb_nslabs * sizeof(io_tlb_addr_t));
/*
* Get the overflow emergency buffer
@@ -249,19 +290,17 @@ swiotlb_late_init_with_default_size(size
if (!io_tlb_overflow_buffer)
goto cleanup4;
- printk(KERN_INFO "Placing %luMB software IO TLB between 0x%lx - "
- "0x%lx\n", bytes >> 20,
- virt_to_bus(io_tlb_start), virt_to_bus(io_tlb_end));
+ swiotlb_print_info(bytes);
return 0;
cleanup4:
- free_pages((unsigned long)io_tlb_orig_addr, get_order(io_tlb_nslabs *
- sizeof(char *)));
+ free_pages((unsigned long)io_tlb_orig_addr,
+ get_order(io_tlb_nslabs * sizeof(io_tlb_addr_t)));
io_tlb_orig_addr = NULL;
cleanup3:
- free_pages((unsigned long)io_tlb_list, get_order(io_tlb_nslabs *
- sizeof(int)));
+ free_pages((unsigned long)io_tlb_list,
+ get_order(io_tlb_nslabs * sizeof(int)));
io_tlb_list = NULL;
cleanup2:
io_tlb_end = NULL;
@@ -271,7 +310,9 @@ cleanup1:
io_tlb_nslabs = req_nslabs;
return -ENOMEM;
}
+#endif
+#ifndef SWIOTLB_ARCH_HAS_NEEDS_MAPPING
static inline int
address_needs_mapping(struct device *hwdev, dma_addr_t addr)
{
@@ -282,11 +323,35 @@ address_needs_mapping(struct device *hwd
return (addr & ~mask) != 0;
}
+static inline int range_needs_mapping(const void *ptr, size_t size)
+{
+ return swiotlb_force;
+}
+
+static inline int order_needs_mapping(unsigned int order)
+{
+ return 0;
+}
+#endif
+
+static void
+__sync_single(io_tlb_addr_t buffer, char *dma_addr, size_t size, int dir)
+{
+#ifndef SWIOTLB_ARCH_HAS_SYNC_SINGLE
+ if (dir == DMA_TO_DEVICE)
+ memcpy(dma_addr, buffer, size);
+ else
+ memcpy(buffer, dma_addr, size);
+#else
+ __swiotlb_arch_sync_single(buffer, dma_addr, size, dir);
+#endif
+}
+
/*
* Allocates bounce buffer and returns its kernel virtual address.
*/
static void *
-map_single(struct device *hwdev, char *buffer, size_t size, int dir)
+map_single(struct device *hwdev, io_tlb_addr_t buffer, size_t size, int dir)
{
unsigned long flags;
char *dma_addr;
@@ -359,7 +424,7 @@ map_single(struct device *hwdev, char *b
*/
io_tlb_orig_addr[index] = buffer;
if (dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL)
- memcpy(dma_addr, buffer, size);
+ __sync_single(buffer, dma_addr, size, DMA_TO_DEVICE);
return dma_addr;
}
@@ -373,17 +438,18 @@ unmap_single(struct device *hwdev, char
unsigned long flags;
int i, count, nslots = ALIGN(size, 1 << IO_TLB_SHIFT) >> IO_TLB_SHIFT;
int index = (dma_addr - io_tlb_start) >> IO_TLB_SHIFT;
- char *buffer = io_tlb_orig_addr[index];
+ io_tlb_addr_t buffer = io_tlb_orig_addr[index];
/*
* First, sync the memory before unmapping the entry
*/
- if (buffer && ((dir == DMA_FROM_DEVICE) || (dir == DMA_BIDIRECTIONAL)))
+ if (!swiotlb_orig_addr_null(buffer)
+ && ((dir == DMA_FROM_DEVICE) || (dir == DMA_BIDIRECTIONAL)))
/*
* bounce... copy the data back into the original buffer * and
* delete the bounce buffer.
*/
- memcpy(buffer, dma_addr, size);
+ __sync_single(buffer, dma_addr, size, DMA_FROM_DEVICE);
/*
* Return the buffer to the free list by setting the corresponding
@@ -416,18 +482,18 @@ sync_single(struct device *hwdev, char *
int dir, int target)
{
int index = (dma_addr - io_tlb_start) >> IO_TLB_SHIFT;
- char *buffer = io_tlb_orig_addr[index];
+ io_tlb_addr_t buffer = io_tlb_orig_addr[index];
switch (target) {
case SYNC_FOR_CPU:
if (likely(dir == DMA_FROM_DEVICE || dir == DMA_BIDIRECTIONAL))
- memcpy(buffer, dma_addr, size);
+ __sync_single(buffer, dma_addr, size, DMA_FROM_DEVICE);
else
BUG_ON(dir != DMA_TO_DEVICE);
break;
case SYNC_FOR_DEVICE:
if (likely(dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL))
- memcpy(dma_addr, buffer, size);
+ __sync_single(buffer, dma_addr, size, DMA_TO_DEVICE);
else
BUG_ON(dir != DMA_FROM_DEVICE);
break;
@@ -436,6 +502,8 @@ sync_single(struct device *hwdev, char *
}
}
+#ifdef SWIOTLB_ARCH_NEED_ALLOC
+
void *
swiotlb_alloc_coherent(struct device *hwdev, size_t size,
dma_addr_t *dma_handle, gfp_t flags)
@@ -451,7 +519,10 @@ swiotlb_alloc_coherent(struct device *hw
*/
flags |= GFP_DMA;
- ret = (void *)__get_free_pages(flags, order);
+ if (!order_needs_mapping(order))
+ ret = (void *)__get_free_pages(flags, order);
+ else
+ ret = NULL;
if (ret && address_needs_mapping(hwdev, virt_to_bus(ret))) {
/*
* The allocated memory isn't reachable by the device.
@@ -489,6 +560,7 @@ swiotlb_alloc_coherent(struct device *hw
*dma_handle = dev_addr;
return ret;
}
+EXPORT_SYMBOL(swiotlb_alloc_coherent);
void
swiotlb_free_coherent(struct device *hwdev, size_t size, void *vaddr,
@@ -501,6 +573,9 @@ swiotlb_free_coherent(struct device *hwd
/* DMA_TO_DEVICE to avoid memcpy in unmap_single */
swiotlb_unmap_single (hwdev, dma_handle, size, DMA_TO_DEVICE);
}
+EXPORT_SYMBOL(swiotlb_free_coherent);
+
+#endif
static void
swiotlb_full(struct device *dev, size_t size, int dir, int do_panic)
@@ -542,13 +617,14 @@ swiotlb_map_single(struct device *hwdev,
* we can safely return the device addr and not worry about bounce
* buffering it.
*/
- if (!address_needs_mapping(hwdev, dev_addr) && !swiotlb_force)
+ if (!range_needs_mapping(ptr, size)
+ && !address_needs_mapping(hwdev, dev_addr))
return dev_addr;
/*
* Oh well, have to allocate and map a bounce buffer.
*/
- map = map_single(hwdev, ptr, size, dir);
+ map = map_single(hwdev, ptr_to_io_tlb_addr(ptr), size, dir);
if (!map) {
swiotlb_full(hwdev, size, dir, 1);
map = io_tlb_overflow_buffer;
@@ -676,17 +752,16 @@ int
swiotlb_map_sg(struct device *hwdev, struct scatterlist *sg, int nelems,
int dir)
{
- void *addr;
dma_addr_t dev_addr;
int i;
BUG_ON(dir == DMA_NONE);
for (i = 0; i < nelems; i++, sg++) {
- addr = SG_ENT_VIRT_ADDRESS(sg);
- dev_addr = virt_to_bus(addr);
- if (swiotlb_force || address_needs_mapping(hwdev, dev_addr)) {
- void *map = map_single(hwdev, addr, sg->length, dir);
+ dev_addr = SG_ENT_PHYS_ADDRESS(sg);
+ if (range_needs_mapping(SG_ENT_VIRT_ADDRESS(sg), sg->length)
+ || address_needs_mapping(hwdev, dev_addr)) {
+ void *map = map_single(hwdev, sg_to_io_tlb_addr(sg), sg->length, dir);
if (!map) {
/* Don't panic here, we expect map_sg users
to do proper error handling. */
@@ -760,6 +835,44 @@ swiotlb_sync_sg_for_device(struct device
swiotlb_sync_sg(hwdev, sg, nelems, dir, SYNC_FOR_DEVICE);
}
+#ifdef SWIOTLB_ARCH_NEED_MAP_PAGE
+
+dma_addr_t
+swiotlb_map_page(struct device *hwdev, struct page *page,
+ unsigned long offset, size_t size,
+ enum dma_data_direction direction)
+{
+ dma_addr_t dev_addr;
+ char *map;
+
+ dev_addr = page_to_bus(page) + offset;
+ if (address_needs_mapping(hwdev, dev_addr)) {
+ map = map_single(hwdev, page_to_io_tlb_addr(page, offset), size, direction);
+ if (!map) {
+ swiotlb_full(hwdev, size, direction, 1);
+ map = io_tlb_overflow_buffer;
+ }
+ dev_addr = virt_to_bus(map);
+ }
+
+ return dev_addr;
+}
+
+void
+swiotlb_unmap_page(struct device *hwdev, dma_addr_t dev_addr,
+ size_t size, enum dma_data_direction direction)
+{
+ char *dma_addr = bus_to_virt(dev_addr);
+
+ BUG_ON(direction == DMA_NONE);
+ if (dma_addr >= io_tlb_start && dma_addr < io_tlb_end)
+ unmap_single(hwdev, dma_addr, size, direction);
+ else if (direction == DMA_FROM_DEVICE)
+ dma_mark_clean(dma_addr, size);
+}
+
+#endif
+
int
swiotlb_dma_mapping_error(dma_addr_t dma_addr)
{
@@ -772,10 +885,13 @@ swiotlb_dma_mapping_error(dma_addr_t dma
* during bus mastering, then you would pass 0x00ffffff as the mask to
* this function.
*/
+#ifndef __swiotlb_dma_supported
+#define __swiotlb_dma_supported(hwdev, mask) (virt_to_bus(io_tlb_end - 1) <= (mask))
+#endif
int
swiotlb_dma_supported(struct device *hwdev, u64 mask)
{
- return virt_to_bus(io_tlb_end - 1) <= mask;
+ return __swiotlb_dma_supported(hwdev, mask);
}
EXPORT_SYMBOL(swiotlb_init);
@@ -790,6 +906,4 @@ EXPORT_SYMBOL_GPL(swiotlb_sync_single_ra
EXPORT_SYMBOL(swiotlb_sync_sg_for_cpu);
EXPORT_SYMBOL(swiotlb_sync_sg_for_device);
EXPORT_SYMBOL(swiotlb_dma_mapping_error);
-EXPORT_SYMBOL(swiotlb_alloc_coherent);
-EXPORT_SYMBOL(swiotlb_free_coherent);
EXPORT_SYMBOL(swiotlb_dma_supported);
-
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