From 3f2aa244ee1a0d17ed5b6c86564d2c1b24d1c96b Mon Sep 17 00:00:00 2001 From: "Maciej W. Rozycki" Date: Wed, 3 Oct 2018 13:21:07 +0100 Subject: [PATCH 1/2] TC: Set DMA masks for devices Fix a TURBOchannel support regression with commit 205e1b7f51e4 ("dma-mapping: warn when there is no coherent_dma_mask") that caused coherent DMA allocations to produce a warning such as: defxx: v1.11 2014/07/01 Lawrence V. Stefani and others tc1: DEFTA at MMIO addr = 0x1e900000, IRQ = 20, Hardware addr = 08-00-2b-a3-a3-29 ------------[ cut here ]------------ WARNING: CPU: 0 PID: 1 at ./include/linux/dma-mapping.h:516 dfx_dev_register+0x670/0x678 Modules linked in: CPU: 0 PID: 1 Comm: swapper Not tainted 4.19.0-rc6 #2 Stack : ffffffff8009ffc0 fffffffffffffec0 0000000000000000 ffffffff80647650 0000000000000000 0000000000000000 ffffffff806f5f80 ffffffffffffffff 0000000000000000 0000000000000000 0000000000000001 ffffffff8065d4e8 98000000031b6300 ffffffff80563478 ffffffff805685b0 ffffffffffffffff 0000000000000000 ffffffff805d6720 0000000000000204 ffffffff80388df8 0000000000000000 0000000000000009 ffffffff8053efd0 ffffffff806657d0 0000000000000000 ffffffff803177f8 0000000000000000 ffffffff806d0000 9800000003078000 980000000307b9e0 000000001e900000 ffffffff80067940 0000000000000000 ffffffff805d6720 0000000000000204 ffffffff80388df8 ffffffff805176c0 ffffffff8004dc78 0000000000000000 ffffffff80067940 ... Call Trace: [] show_stack+0xa0/0x130 [] __warn+0x128/0x170 ---[ end trace b1d1e094f67f3bb2 ]--- This is because the TURBOchannel bus driver fails to set the coherent DMA mask for devices enumerated. Set the regular and coherent DMA masks for TURBOchannel devices then, observing that the bus protocol supports a 34-bit (16GiB) DMA address space, by interpreting the value presented in the address cycle across the 32 `ad' lines as a 32-bit word rather than byte address[1]. The architectural size of the TURBOchannel DMA address space exceeds the maximum amount of RAM any actual TURBOchannel system in existence may have, hence both masks are the same. This removes the warning shown above. References: [1] "TURBOchannel Hardware Specification", EK-369AA-OD-007B, Digital Equipment Corporation, January 1993, Section "DMA", pp. 1-15 -- 1-17 Signed-off-by: Maciej W. Rozycki Signed-off-by: Paul Burton Patchwork: https://patchwork.linux-mips.org/patch/20835/ Fixes: 205e1b7f51e4 ("dma-mapping: warn when there is no coherent_dma_mask") Cc: stable@vger.kernel.org # 4.16+ Cc: Ralf Baechle --- drivers/tc/tc.c | 8 +++++++- include/linux/tc.h | 1 + 2 files changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/tc/tc.c b/drivers/tc/tc.c index 3be9519654e5..cf3fad2cb871 100644 --- a/drivers/tc/tc.c +++ b/drivers/tc/tc.c @@ -2,7 +2,7 @@ * TURBOchannel bus services. * * Copyright (c) Harald Koerfgen, 1998 - * Copyright (c) 2001, 2003, 2005, 2006 Maciej W. Rozycki + * Copyright (c) 2001, 2003, 2005, 2006, 2018 Maciej W. Rozycki * Copyright (c) 2005 James Simmons * * This file is subject to the terms and conditions of the GNU @@ -10,6 +10,7 @@ * directory of this archive for more details. */ #include +#include #include #include #include @@ -92,6 +93,11 @@ static void __init tc_bus_add_devices(struct tc_bus *tbus) tdev->dev.bus = &tc_bus_type; tdev->slot = slot; + /* TURBOchannel has 34-bit DMA addressing (16GiB space). */ + tdev->dma_mask = DMA_BIT_MASK(34); + tdev->dev.dma_mask = &tdev->dma_mask; + tdev->dev.coherent_dma_mask = DMA_BIT_MASK(34); + for (i = 0; i < 8; i++) { tdev->firmware[i] = readb(module + offset + TC_FIRM_VER + 4 * i); diff --git a/include/linux/tc.h b/include/linux/tc.h index f92511e57cdb..a60639f37963 100644 --- a/include/linux/tc.h +++ b/include/linux/tc.h @@ -84,6 +84,7 @@ struct tc_dev { device. */ struct device dev; /* Generic device interface. */ struct resource resource; /* Address space of this device. */ + u64 dma_mask; /* DMA addressable range. */ char vendor[9]; char name[9]; char firmware[9]; From c61c7def1fa0a722610d89790e0255b74f3c07dd Mon Sep 17 00:00:00 2001 From: Huacai Chen Date: Tue, 16 Oct 2018 09:20:42 +0800 Subject: [PATCH 2/2] MIPS: VDSO: Reduce VDSO_RANDOMIZE_SIZE to 64MB for 64bit Commit ea7e0480a4b6 ("MIPS: VDSO: Always map near top of user memory") set VDSO_RANDOMIZE_SIZE to 256MB for 64bit kernel. But take a look at arch/mips/mm/mmap.c we can see that MIN_GAP is 128MB, which means the mmap_base may be at (user_address_top - 128MB). This make the stack be surrounded by mmaped areas, then stack expanding fails and causes a segmentation fault. Therefore, VDSO_RANDOMIZE_SIZE should be less than MIN_GAP and this patch reduce it to 64MB. Signed-off-by: Huacai Chen Signed-off-by: Paul Burton Fixes: ea7e0480a4b6 ("MIPS: VDSO: Always map near top of user memory") Patchwork: https://patchwork.linux-mips.org/patch/20910/ Cc: Ralf Baechle Cc: James Hogan Cc: linux-mips@linux-mips.org Cc: Fuxin Zhang Cc: Zhangjin Wu Cc: Huacai Chen --- arch/mips/include/asm/processor.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/mips/include/asm/processor.h b/arch/mips/include/asm/processor.h index 49d6046ca1d0..c373eb605040 100644 --- a/arch/mips/include/asm/processor.h +++ b/arch/mips/include/asm/processor.h @@ -81,7 +81,7 @@ extern unsigned int vced_count, vcei_count; #endif -#define VDSO_RANDOMIZE_SIZE (TASK_IS_32BIT_ADDR ? SZ_1M : SZ_256M) +#define VDSO_RANDOMIZE_SIZE (TASK_IS_32BIT_ADDR ? SZ_1M : SZ_64M) extern unsigned long mips_stack_top(void); #define STACK_TOP mips_stack_top()