From 84532a0fc3d5811dca8e3726fe4d372ea87bd7c6 Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt Date: Wed, 27 May 2009 13:33:14 +1000 Subject: Revert "powerpc: Rework dma-noncoherent to use generic vmalloc layer" This reverts commit 33f00dcedb0e22cdb156a23632814fc580fcfcf8. While it was a good idea to try to use the mm/vmalloc.c allocator instead of our own (in fact, ours is itself a dup on an old variant of the vmalloc one), unfortunately, the approach is terminally busted since dma_alloc_coherent() can be called at interrupt time or in atomic contexts and there's little chances we'll make the code in mm/vmalloc.c cope with\ that :-( Until we can get the generic code to forbid that idiocy and fix all drivers abusing it, we pretty much have no choice but revert to our custom virtual space allocator. There's also a problem with SMP safety since freeing such mapping would require an IPI which cannot be done at interrupt time. However, right now, I don't think we support any platform that is both SMP and has non-coherent DMA (don't laugh, I know such things do exist !) so we can sort that out later. Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/Kconfig | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) (limited to 'arch/powerpc/Kconfig') diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index a0d1146a0578..3bb43adce44d 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -868,6 +868,31 @@ config TASK_SIZE default "0x80000000" if PPC_PREP || PPC_8xx default "0xc0000000" +config CONSISTENT_START_BOOL + bool "Set custom consistent memory pool address" + depends on ADVANCED_OPTIONS && NOT_COHERENT_CACHE + help + This option allows you to set the base virtual address + of the consistent memory pool. This pool of virtual + memory is used to make consistent memory allocations. + +config CONSISTENT_START + hex "Base virtual address of consistent memory pool" if CONSISTENT_START_BOOL + default "0xfd000000" if (NOT_COHERENT_CACHE && 8xx) + default "0xff100000" if NOT_COHERENT_CACHE + +config CONSISTENT_SIZE_BOOL + bool "Set custom consistent memory pool size" + depends on ADVANCED_OPTIONS && NOT_COHERENT_CACHE + help + This option allows you to set the size of the + consistent memory pool. This pool of virtual memory + is used to make consistent memory allocations. + +config CONSISTENT_SIZE + hex "Size of consistent memory pool" if CONSISTENT_SIZE_BOOL + default "0x00200000" if NOT_COHERENT_CACHE + config PIN_TLB bool "Pinned Kernel TLBs (860 ONLY)" depends on ADVANCED_OPTIONS && 8xx -- cgit v1.2.2 From 8b31e49d1d75729c1da9009664ba52abd1adc628 Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt Date: Wed, 27 May 2009 13:50:33 +1000 Subject: powerpc: Fix up dma_alloc_coherent() on platforms without cache coherency. The implementation we just revived has issues, such as using a Kconfig-defined virtual address area in kernel space that nothing actually carves out (and thus will overlap whatever is there), or having some dependencies on being self contained in a single PTE page which adds unnecessary constraints on the kernel virtual address space. This fixes it by using more classic PTE accessors and automatically locating the area for consistent memory, carving an appropriate hole in the kernel virtual address space, leaving only the size of that area as a Kconfig option. It also brings some dma-mask related fixes from the ARM implementation which was almost identical initially but grew its own fixes. Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/Kconfig | 13 ------------- 1 file changed, 13 deletions(-) (limited to 'arch/powerpc/Kconfig') diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 3bb43adce44d..cdc9a6ff4be8 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -868,19 +868,6 @@ config TASK_SIZE default "0x80000000" if PPC_PREP || PPC_8xx default "0xc0000000" -config CONSISTENT_START_BOOL - bool "Set custom consistent memory pool address" - depends on ADVANCED_OPTIONS && NOT_COHERENT_CACHE - help - This option allows you to set the base virtual address - of the consistent memory pool. This pool of virtual - memory is used to make consistent memory allocations. - -config CONSISTENT_START - hex "Base virtual address of consistent memory pool" if CONSISTENT_START_BOOL - default "0xfd000000" if (NOT_COHERENT_CACHE && 8xx) - default "0xff100000" if NOT_COHERENT_CACHE - config CONSISTENT_SIZE_BOOL bool "Set custom consistent memory pool size" depends on ADVANCED_OPTIONS && NOT_COHERENT_CACHE -- cgit v1.2.2