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sparc: use generic dma_noncoherent_ops
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Switch to the generic noncoherent direct mapping implementation.

This removes the previous sync_single_for_device implementation, which
looks bogus given that no syncing is happening in the similar but more
important map_single case.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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@davem330
Christoph Hellwig authored and davem330 committed Aug 21, 2018
1 parent 778a339 commit dfaad39
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Showing 3 changed files with 35 additions and 165 deletions.
2 changes: 2 additions & 0 deletions arch/sparc/Kconfig
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Original file line number Diff line number Diff line change
Expand Up @@ -48,6 +48,8 @@ config SPARC

config SPARC32
def_bool !64BIT
select ARCH_HAS_SYNC_DMA_FOR_CPU
select DMA_NONCOHERENT_OPS
select GENERIC_ATOMIC64
select CLZ_TAB
select HAVE_UID16
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5 changes: 2 additions & 3 deletions arch/sparc/include/asm/dma-mapping.h
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Original file line number Diff line number Diff line change
Expand Up @@ -7,19 +7,18 @@
#include <linux/dma-debug.h>

extern const struct dma_map_ops *dma_ops;
extern const struct dma_map_ops pci32_dma_ops;

extern struct bus_type pci_bus_type;

static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
{
#ifdef CONFIG_SPARC_LEON
if (sparc_cpu_model == sparc_leon)
return &pci32_dma_ops;
return &dma_noncoherent_ops;
#endif
#if defined(CONFIG_SPARC32) && defined(CONFIG_PCI)
if (bus == &pci_bus_type)
return &pci32_dma_ops;
return &dma_noncoherent_ops;
#endif
return dma_ops;
}
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193 changes: 31 additions & 162 deletions arch/sparc/kernel/ioport.c
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Original file line number Diff line number Diff line change
Expand Up @@ -38,6 +38,7 @@
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/scatterlist.h>
#include <linux/dma-noncoherent.h>
#include <linux/of_device.h>

#include <asm/io.h>
Expand Down Expand Up @@ -434,42 +435,41 @@ arch_initcall(sparc_register_ioport);
/* Allocate and map kernel buffer using consistent mode DMA for a device.
* hwdev should be valid struct pci_dev pointer for PCI devices.
*/
static void *pci32_alloc_coherent(struct device *dev, size_t len,
dma_addr_t *pba, gfp_t gfp,
unsigned long attrs)
void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle,
gfp_t gfp, unsigned long attrs)
{
unsigned long len_total = PAGE_ALIGN(len);
unsigned long len_total = PAGE_ALIGN(size);
void *va;
struct resource *res;
int order;

if (len == 0) {
if (size == 0) {
return NULL;
}
if (len > 256*1024) { /* __get_free_pages() limit */
if (size > 256*1024) { /* __get_free_pages() limit */
return NULL;
}

order = get_order(len_total);
va = (void *) __get_free_pages(gfp, order);
if (va == NULL) {
printk("pci_alloc_consistent: no %ld pages\n", len_total>>PAGE_SHIFT);
printk("%s: no %ld pages\n", __func__, len_total>>PAGE_SHIFT);
goto err_nopages;
}

if ((res = kzalloc(sizeof(struct resource), GFP_KERNEL)) == NULL) {
printk("pci_alloc_consistent: no core\n");
printk("%s: no core\n", __func__);
goto err_nomem;
}

if (allocate_resource(&_sparc_dvma, res, len_total,
_sparc_dvma.start, _sparc_dvma.end, PAGE_SIZE, NULL, NULL) != 0) {
printk("pci_alloc_consistent: cannot occupy 0x%lx", len_total);
printk("%s: cannot occupy 0x%lx", __func__, len_total);
goto err_nova;
}
srmmu_mapiorange(0, virt_to_phys(va), res->start, len_total);

*pba = virt_to_phys(va); /* equals virt_to_bus (R.I.P.) for us. */
*dma_handle = virt_to_phys(va);
return (void *) res->start;

err_nova:
Expand All @@ -481,184 +481,53 @@ static void *pci32_alloc_coherent(struct device *dev, size_t len,
}

/* Free and unmap a consistent DMA buffer.
* cpu_addr is what was returned from pci_alloc_consistent,
* size must be the same as what as passed into pci_alloc_consistent,
* and likewise dma_addr must be the same as what *dma_addrp was set to.
* cpu_addr is what was returned arch_dma_alloc, size must be the same as what
* was passed into arch_dma_alloc, and likewise dma_addr must be the same as
* what *dma_ndler was set to.
*
* References to the memory and mappings associated with cpu_addr/dma_addr
* past this call are illegal.
*/
static void pci32_free_coherent(struct device *dev, size_t n, void *p,
dma_addr_t ba, unsigned long attrs)
void arch_dma_free(struct device *dev, size_t size, void *cpu_addr,
dma_addr_t dma_addr, unsigned long attrs)
{
struct resource *res;

if ((res = lookup_resource(&_sparc_dvma,
(unsigned long)p)) == NULL) {
printk("pci_free_consistent: cannot free %p\n", p);
(unsigned long)cpu_addr)) == NULL) {
printk("%s: cannot free %p\n", __func__, cpu_addr);
return;
}

if (((unsigned long)p & (PAGE_SIZE-1)) != 0) {
printk("pci_free_consistent: unaligned va %p\n", p);
if (((unsigned long)cpu_addr & (PAGE_SIZE-1)) != 0) {
printk("%s: unaligned va %p\n", __func__, cpu_addr);
return;
}

n = PAGE_ALIGN(n);
if (resource_size(res) != n) {
printk("pci_free_consistent: region 0x%lx asked 0x%lx\n",
(long)resource_size(res), (long)n);
size = PAGE_ALIGN(size);
if (resource_size(res) != size) {
printk("%s: region 0x%lx asked 0x%zx\n", __func__,
(long)resource_size(res), size);
return;
}

dma_make_coherent(ba, n);
srmmu_unmapiorange((unsigned long)p, n);
dma_make_coherent(dma_addr, size);
srmmu_unmapiorange((unsigned long)cpu_addr, size);

release_resource(res);
kfree(res);
free_pages((unsigned long)phys_to_virt(ba), get_order(n));
}

/*
* Same as pci_map_single, but with pages.
*/
static dma_addr_t pci32_map_page(struct device *dev, struct page *page,
unsigned long offset, size_t size,
enum dma_data_direction dir,
unsigned long attrs)
{
/* IIep is write-through, not flushing. */
return page_to_phys(page) + offset;
}

static void pci32_unmap_page(struct device *dev, dma_addr_t ba, size_t size,
enum dma_data_direction dir, unsigned long attrs)
{
if (dir != PCI_DMA_TODEVICE && !(attrs & DMA_ATTR_SKIP_CPU_SYNC))
dma_make_coherent(ba, PAGE_ALIGN(size));
}

/* Map a set of buffers described by scatterlist in streaming
* mode for DMA. This is the scatter-gather version of the
* above pci_map_single interface. Here the scatter gather list
* elements are each tagged with the appropriate dma address
* and length. They are obtained via sg_dma_{address,length}(SG).
*
* NOTE: An implementation may be able to use a smaller number of
* DMA address/length pairs than there are SG table elements.
* (for example via virtual mapping capabilities)
* The routine returns the number of addr/length pairs actually
* used, at most nents.
*
* Device ownership issues as mentioned above for pci_map_single are
* the same here.
*/
static int pci32_map_sg(struct device *device, struct scatterlist *sgl,
int nents, enum dma_data_direction dir,
unsigned long attrs)
{
struct scatterlist *sg;
int n;

/* IIep is write-through, not flushing. */
for_each_sg(sgl, sg, nents, n) {
sg->dma_address = sg_phys(sg);
sg->dma_length = sg->length;
}
return nents;
}

/* Unmap a set of streaming mode DMA translations.
* Again, cpu read rules concerning calls here are the same as for
* pci_unmap_single() above.
*/
static void pci32_unmap_sg(struct device *dev, struct scatterlist *sgl,
int nents, enum dma_data_direction dir,
unsigned long attrs)
{
struct scatterlist *sg;
int n;

if (dir != PCI_DMA_TODEVICE && !(attrs & DMA_ATTR_SKIP_CPU_SYNC)) {
for_each_sg(sgl, sg, nents, n) {
dma_make_coherent(sg_phys(sg), PAGE_ALIGN(sg->length));
}
}
}

/* Make physical memory consistent for a single
* streaming mode DMA translation before or after a transfer.
*
* If you perform a pci_map_single() but wish to interrogate the
* buffer using the cpu, yet do not wish to teardown the PCI dma
* mapping, you must call this function before doing so. At the
* next point you give the PCI dma address back to the card, you
* must first perform a pci_dma_sync_for_device, and then the
* device again owns the buffer.
*/
static void pci32_sync_single_for_cpu(struct device *dev, dma_addr_t ba,
size_t size, enum dma_data_direction dir)
{
if (dir != PCI_DMA_TODEVICE) {
dma_make_coherent(ba, PAGE_ALIGN(size));
}
}

static void pci32_sync_single_for_device(struct device *dev, dma_addr_t ba,
size_t size, enum dma_data_direction dir)
{
if (dir != PCI_DMA_TODEVICE) {
dma_make_coherent(ba, PAGE_ALIGN(size));
}
free_pages((unsigned long)phys_to_virt(dma_addr), get_order(size));
}

/* Make physical memory consistent for a set of streaming
* mode DMA translations after a transfer.
*
* The same as pci_dma_sync_single_* but for a scatter-gather list,
* same rules and usage.
*/
static void pci32_sync_sg_for_cpu(struct device *dev, struct scatterlist *sgl,
int nents, enum dma_data_direction dir)
{
struct scatterlist *sg;
int n;

if (dir != PCI_DMA_TODEVICE) {
for_each_sg(sgl, sg, nents, n) {
dma_make_coherent(sg_phys(sg), PAGE_ALIGN(sg->length));
}
}
}
/* IIep is write-through, not flushing on cpu to device transfer. */

static void pci32_sync_sg_for_device(struct device *device, struct scatterlist *sgl,
int nents, enum dma_data_direction dir)
void arch_sync_dma_for_cpu(struct device *dev, phys_addr_t paddr,
size_t size, enum dma_data_direction dir)
{
struct scatterlist *sg;
int n;

if (dir != PCI_DMA_TODEVICE) {
for_each_sg(sgl, sg, nents, n) {
dma_make_coherent(sg_phys(sg), PAGE_ALIGN(sg->length));
}
}
if (dir != PCI_DMA_TODEVICE)
dma_make_coherent(paddr, PAGE_ALIGN(size));
}

/* note: leon re-uses pci32_dma_ops */
const struct dma_map_ops pci32_dma_ops = {
.alloc = pci32_alloc_coherent,
.free = pci32_free_coherent,
.map_page = pci32_map_page,
.unmap_page = pci32_unmap_page,
.map_sg = pci32_map_sg,
.unmap_sg = pci32_unmap_sg,
.sync_single_for_cpu = pci32_sync_single_for_cpu,
.sync_single_for_device = pci32_sync_single_for_device,
.sync_sg_for_cpu = pci32_sync_sg_for_cpu,
.sync_sg_for_device = pci32_sync_sg_for_device,
};
EXPORT_SYMBOL(pci32_dma_ops);

const struct dma_map_ops *dma_ops = &sbus_dma_ops;
EXPORT_SYMBOL(dma_ops);

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