From d89e2378a97fafdc74cbf997e7c88af75b81610a Mon Sep 17 00:00:00 2001 From: Robin Murphy Date: Thu, 12 Oct 2017 16:56:14 +0100 Subject: drivers: flag buses which demand DMA configuration We do not want the common dma_configure() pathway to apply indiscriminately to all devices, since there are plenty of buses which do not have DMA capability, and if their child devices were used for DMA API calls it would only be indicative of a driver bug. However, there are a number of buses for which DMA is implicitly expected even when not described by firmware - those we whitelist with an automatic opt-in to dma_configure(), assuming that the DMA address space and the physical address space are equivalent if not otherwise specified. Commit 723288836628 ("of: restrict DMA configuration") introduced a short-term fix by comparing explicit bus types, but this approach is far from pretty, doesn't scale well, and fails to cope at all with bus drivers which may be built as modules, like host1x. Let's refine things by making that opt-in a property of the bus type, which neatly addresses those problems and lets the decision of whether firmware description of DMA capability should be optional or mandatory stay internal to the bus drivers themselves. Signed-off-by: Robin Murphy Acked-by: Rob Herring Acked-by: Greg Kroah-Hartman Acked-by: Thierry Reding Signed-off-by: Christoph Hellwig --- drivers/amba/bus.c | 1 + drivers/base/platform.c | 1 + drivers/gpu/host1x/bus.c | 1 + drivers/of/device.c | 8 +------- drivers/pci/pci-driver.c | 1 + 5 files changed, 5 insertions(+), 7 deletions(-) (limited to 'drivers') diff --git a/drivers/amba/bus.c b/drivers/amba/bus.c index e0f74ddc22b7..594c228d2f02 100644 --- a/drivers/amba/bus.c +++ b/drivers/amba/bus.c @@ -195,6 +195,7 @@ struct bus_type amba_bustype = { .match = amba_match, .uevent = amba_uevent, .pm = &amba_pm, + .force_dma = true, }; static int __init amba_init(void) diff --git a/drivers/base/platform.c b/drivers/base/platform.c index 9045c5f3734e..c203fb90c1a0 100644 --- a/drivers/base/platform.c +++ b/drivers/base/platform.c @@ -1143,6 +1143,7 @@ struct bus_type platform_bus_type = { .match = platform_match, .uevent = platform_uevent, .pm = &platform_dev_pm_ops, + .force_dma = true, }; EXPORT_SYMBOL_GPL(platform_bus_type); diff --git a/drivers/gpu/host1x/bus.c b/drivers/gpu/host1x/bus.c index f9cde03030fd..ed03b3243195 100644 --- a/drivers/gpu/host1x/bus.c +++ b/drivers/gpu/host1x/bus.c @@ -320,6 +320,7 @@ struct bus_type host1x_bus_type = { .name = "host1x", .match = host1x_device_match, .pm = &host1x_device_pm_ops, + .force_dma = true, }; static void __host1x_device_del(struct host1x_device *device) diff --git a/drivers/of/device.c b/drivers/of/device.c index 64b710265d39..25bddf9c9fe1 100644 --- a/drivers/of/device.c +++ b/drivers/of/device.c @@ -9,9 +9,7 @@ #include #include #include -#include #include -#include #include #include "of_private.h" @@ -101,11 +99,7 @@ int of_dma_configure(struct device *dev, struct device_node *np) * DMA configuration regardless of whether "dma-ranges" is * correctly specified or not. */ - if (!dev_is_pci(dev) && -#ifdef CONFIG_ARM_AMBA - dev->bus != &amba_bustype && -#endif - dev->bus != &platform_bus_type) + if (!dev->bus->force_dma) return ret == -ENODEV ? 0 : ret; dma_addr = offset = 0; diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c index 11bd267fc137..38bdb97b6dc6 100644 --- a/drivers/pci/pci-driver.c +++ b/drivers/pci/pci-driver.c @@ -1466,6 +1466,7 @@ struct bus_type pci_bus_type = { .drv_groups = pci_drv_groups, .pm = PCI_PM_OPS_PTR, .num_vf = pci_bus_num_vf, + .force_dma = true, }; EXPORT_SYMBOL(pci_bus_type); -- cgit v1.2.3 From acfef4f126a716018127dcf147be0cc16c304e72 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 13 Jul 2017 16:12:05 +0200 Subject: floppy: consolidate the dummy fd_cacheflush definition Only mips defines this helper, so remove all the other arch definitions. Signed-off-by: Christoph Hellwig Reviewed-by: Robin Murphy --- drivers/block/floppy.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'drivers') diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c index 60c086a53609..a54183935aa1 100644 --- a/drivers/block/floppy.c +++ b/drivers/block/floppy.c @@ -275,6 +275,10 @@ static int set_next_request(void); #define fd_dma_mem_alloc(size) __get_dma_pages(GFP_KERNEL, get_order(size)) #endif +#ifndef fd_cacheflush +#define fd_cacheflush(addr, size) /* nothing... */ +#endif + static inline void fallback_on_nodma_alloc(char **addr, size_t l) { #ifdef FLOPPY_CAN_FALLBACK_ON_NODMA -- cgit v1.2.3 From e0c6584df9c414b50de17e1abc1099f7501bbb60 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Sun, 27 Aug 2017 10:35:40 +0200 Subject: sh: make dma_cache_sync a no-op sh does not implement DMA_ATTR_NON_CONSISTENT allocations, so it doesn't make any sense to do any work in dma_cache_sync given that it must be a no-op when dma_alloc_attrs returns coherent memory. On the other hand sh uses dma_cache_sync internally in the dma_ops implementation and for the maple bus that does not use the DMA API, so a the old functionality for dma_cache_sync is still provided under the name sh_sync_dma_for_device, and without the redundant dev argument. While at it two of the syncing dma_ops also go the proper _for_device postfix. Signed-off-by: Christoph Hellwig Reviewed-by: Robin Murphy --- drivers/sh/maple/maple.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) (limited to 'drivers') diff --git a/drivers/sh/maple/maple.c b/drivers/sh/maple/maple.c index bec81c2404f7..7525039d812c 100644 --- a/drivers/sh/maple/maple.c +++ b/drivers/sh/maple/maple.c @@ -300,7 +300,7 @@ static void maple_send(void) mutex_unlock(&maple_wlist_lock); if (maple_packets > 0) { for (i = 0; i < (1 << MAPLE_DMA_PAGES); i++) - dma_cache_sync(0, maple_sendbuf + i * PAGE_SIZE, + sh_sync_dma_for_device(maple_sendbuf + i * PAGE_SIZE, PAGE_SIZE, DMA_BIDIRECTIONAL); } @@ -642,8 +642,7 @@ static void maple_dma_handler(struct work_struct *work) list_for_each_entry_safe(mq, nmq, &maple_sentq, list) { mdev = mq->dev; recvbuf = mq->recvbuf->buf; - dma_cache_sync(&mdev->dev, recvbuf, 0x400, - DMA_FROM_DEVICE); + sh_sync_dma_for_device(recvbuf, 0x400, DMA_FROM_DEVICE); code = recvbuf[0]; kfree(mq->sendbuf); list_del_init(&mq->list); -- cgit v1.2.3