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sparc32: use DMA_DIRECT_REMAP

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Use the generic dma remapping allocator instead of open coding it.
This also avoids setting up page tables from irq context which is
generally dangerous and uses the atomic pool instead.

Note that this changes the kernel virtual address at which the
dma coherent memory is mapped from the DVMA_VADDR region to the general
vmalloc pool.  I could not find any indication that this matters
for the hardware.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Andreas Larsson <andreas@gaisler.com>
Acked-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Christoph Hellwig 2021-09-13 18:44:55 +02:00
parent 837e80b3a5
commit 7d6db80b7d
2 changed files with 2 additions and 55 deletions
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3
arch/sparc/Kconfig
View file

@ -53,8 +53,9 @@ config SPARC32
def_bool !64BIT
select ARCH_32BIT_OFF_T
select ARCH_HAS_SYNC_DMA_FOR_CPU
select GENERIC_ATOMIC64
select CLZ_TAB
select DMA_DIRECT_REMAP
select GENERIC_ATOMIC64
select HAVE_UID16
select OLD_SIGACTION
select ZONE_DMA

54
arch/sparc/kernel/ioport.c
View file

@ -300,60 +300,6 @@ arch_initcall(sparc_register_ioport);
#endif /* CONFIG_SBUS */
/* Allocate and map kernel buffer using consistent mode DMA for a device.
* hwdev should be valid struct pci_dev pointer for PCI devices.
*/
void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle,
gfp_t gfp, unsigned long attrs)
{
unsigned long addr;
void *va;
if (!size || size > 256 * 1024) /* __get_free_pages() limit */
return NULL;
size = PAGE_ALIGN(size);
va = (void *) __get_free_pages(gfp | __GFP_ZERO, get_order(size));
if (!va) {
printk("%s: no %zd pages\n", __func__, size >> PAGE_SHIFT);
return NULL;
}
addr = sparc_dma_alloc_resource(dev, size);
if (!addr)
goto err_nomem;
srmmu_mapiorange(0, virt_to_phys(va), addr, size);
*dma_handle = virt_to_phys(va);
return (void *)addr;
err_nomem:
free_pages((unsigned long)va, get_order(size));
return NULL;
}
/* Free and unmap a consistent DMA buffer.
* 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.
*/
void arch_dma_free(struct device *dev, size_t size, void *cpu_addr,
dma_addr_t dma_addr, unsigned long attrs)
{
size = PAGE_ALIGN(size);
if (!sparc_dma_free_resource(cpu_addr, size))
return;
srmmu_unmapiorange((unsigned long)cpu_addr, size);
free_pages((unsigned long)phys_to_virt(dma_addr), get_order(size));
}
/*
* IIep is write-through, not flushing on cpu to device transfer.
*