From 832183d0409a941788e4c27682b2ad5164aec5d9 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 13 Sep 2021 18:39:38 +0200 Subject: sparc32: remove dma_make_coherent LEON only needs snooping when DMA accesses are not seen on the processor bus. Given that coherent allocations are mapped uncached this can't happen for those, so open code the d-cache flushing logic in the only remaing place that needs it, arch_sync_dma_for_cpu. Signed-off-by: Christoph Hellwig --- arch/sparc/kernel/ioport.c | 26 ++++++++++---------------- 1 file changed, 10 insertions(+), 16 deletions(-) diff --git a/arch/sparc/kernel/ioport.c b/arch/sparc/kernel/ioport.c index 7ceae24b0ca99..3eb748e862220 100644 --- a/arch/sparc/kernel/ioport.c +++ b/arch/sparc/kernel/ioport.c @@ -52,17 +52,6 @@ #include #include -/* This function must make sure that caches and memory are coherent after DMA - * On LEON systems without cache snooping it flushes the entire D-CACHE. - */ -static inline void dma_make_coherent(unsigned long pa, unsigned long len) -{ - if (sparc_cpu_model == sparc_leon) { - if (!sparc_leon3_snooping_enabled()) - leon_flush_dcache_all(); - } -} - static void __iomem *_sparc_ioremap(struct resource *res, u32 bus, u32 pa, int sz); static void __iomem *_sparc_alloc_io(unsigned int busno, unsigned long phys, unsigned long size, char *name); @@ -361,18 +350,23 @@ void arch_dma_free(struct device *dev, size_t size, void *cpu_addr, if (!sparc_dma_free_resource(cpu_addr, size)) return; - dma_make_coherent(dma_addr, size); 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. */ - +/* + * IIep is write-through, not flushing on cpu to device transfer. + * + * On LEON systems without cache snooping, the entire D-CACHE must be flushed to + * make DMA to cacheable memory coherent. + */ void arch_sync_dma_for_cpu(phys_addr_t paddr, size_t size, enum dma_data_direction dir) { - if (dir != PCI_DMA_TODEVICE) - dma_make_coherent(paddr, PAGE_ALIGN(size)); + if (dir != PCI_DMA_TODEVICE && + sparc_cpu_model == sparc_leon && + !sparc_leon3_snooping_enabled()) + leon_flush_dcache_all(); } #ifdef CONFIG_PROC_FS -- 2.30.2