diff mbox series

[fixes,2/3] MIPS: Loongson64: Enable DMA noncoherent support

Message ID 20231101-loongson64_fixes-v1-2-2a2582a4bfa9@flygoat.com
State New
Headers
Series MIPS: Loongson64: Fix some long-term issues |

Commit Message

Jiaxun Yang Nov. 1, 2023, 11:39 a.m. UTC 
  There are some Loongson64 systems come with broken coherent DMA
support, firmware will set a bit in boot_param and pass nocoherentio
in cmdline.

However nonconherent support was missed out when spin off Loongson-2EF
form Loongson64, and that boot_param change never made itself into
upstream.

Support DMA noncoherent properly to get those systems work.

Cc: stable@vger.kernel.org
Fixes: 71e2f4dd5a65 ("MIPS: Fork loongson2ef from loongson64")
Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
---
 arch/mips/Kconfig                                  | 2 ++
 arch/mips/include/asm/mach-loongson64/boot_param.h | 3 ++-
 arch/mips/loongson64/env.c                         | 9 ++++++++-
 3 files changed, 12 insertions(+), 2 deletions(-)

Comments

Sergey Shtylyov Nov. 1, 2023, 4:27 p.m. UTC | #1 
On 11/1/23 2:39 PM, Jiaxun Yang wrote:

> There are some Loongson64 systems come with broken coherent DMA
> support, firmware will set a bit in boot_param and pass nocoherentio
> in cmdline.
> 
> However nonconherent support was missed out when spin off Loongson-2EF
> form Loongson64, and that boot_param change never made itself into
> upstream.
> 
> Support DMA noncoherent properly to get those systems work.

   Working.

> 
> Cc: stable@vger.kernel.org
> Fixes: 71e2f4dd5a65 ("MIPS: Fork loongson2ef from loongson64")
> Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
[...]

> diff --git a/arch/mips/include/asm/mach-loongson64/boot_param.h b/arch/mips/include/asm/mach-loongson64/boot_param.h
> index 035b1a69e2d0..c454ef734c45 100644
> --- a/arch/mips/include/asm/mach-loongson64/boot_param.h
> +++ b/arch/mips/include/asm/mach-loongson64/boot_param.h
> @@ -117,7 +117,8 @@ struct irq_source_routing_table {
>  	u64 pci_io_start_addr;
>  	u64 pci_io_end_addr;
>  	u64 pci_config_addr;
> -	u32 dma_mask_bits;
> +	u16 dma_mask_bits;
> +	u16 dma_noncoherent;
>  } __packed;
>  
>  struct interface_info {
> diff --git a/arch/mips/loongson64/env.c b/arch/mips/loongson64/env.c
> index c961e2999f15..df0e92cd3920 100644
> --- a/arch/mips/loongson64/env.c
> +++ b/arch/mips/loongson64/env.c
> @@ -13,6 +13,8 @@
>   * Copyright (C) 2009 Lemote Inc.
>   * Author: Wu Zhangjin, wuzhangjin@gmail.com
>   */
> +
> +#include <linux/dma-map-ops.h>
>  #include <linux/export.h>
>  #include <linux/pci_ids.h>
>  #include <asm/bootinfo.h>
> @@ -147,8 +149,13 @@ void __init prom_lefi_init_env(void)
>  
>  	loongson_sysconf.dma_mask_bits = eirq_source->dma_mask_bits;
>  	if (loongson_sysconf.dma_mask_bits < 32 ||
> -		loongson_sysconf.dma_mask_bits > 64)
> +		loongson_sysconf.dma_mask_bits > 64) {

   Please indent this line differently, so it doesn't blend
with the following line (either start it in the same column
as the *if* expression above, or add 1 more tab).

>  		loongson_sysconf.dma_mask_bits = 32;
> +		dma_default_coherent = true;
> +	} else

   The kernel style dictates that you need to add {} on the *else*
branchh too.

> +		dma_default_coherent = !eirq_source->dma_noncoherent;
> +
> +	pr_info("DMA coherent: %s\n", dma_default_coherent ? "on" : "off");

   Maybe "Coherent DMA: %s\n"?

[...]

MBR, Sergey
diff mbox series

Patch

diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 76db82542519..797ae590ebdb 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -460,6 +460,7 @@  config MACH_LOONGSON2EF
 
 config MACH_LOONGSON64
 	bool "Loongson 64-bit family of machines"
+	select ARCH_DMA_DEFAULT_COHERENT
 	select ARCH_SPARSEMEM_ENABLE
 	select ARCH_MIGHT_HAVE_PC_PARPORT
 	select ARCH_MIGHT_HAVE_PC_SERIO
@@ -1251,6 +1252,7 @@  config CPU_LOONGSON64
 	select CPU_SUPPORTS_MSA
 	select CPU_DIEI_BROKEN if !LOONGSON3_ENHANCEMENT
 	select CPU_MIPSR2_IRQ_VI
+	select DMA_NONCOHERENT
 	select WEAK_ORDERING
 	select WEAK_REORDERING_BEYOND_LLSC
 	select MIPS_ASID_BITS_VARIABLE
diff --git a/arch/mips/include/asm/mach-loongson64/boot_param.h b/arch/mips/include/asm/mach-loongson64/boot_param.h
index 035b1a69e2d0..c454ef734c45 100644
--- a/arch/mips/include/asm/mach-loongson64/boot_param.h
+++ b/arch/mips/include/asm/mach-loongson64/boot_param.h
@@ -117,7 +117,8 @@  struct irq_source_routing_table {
 	u64 pci_io_start_addr;
 	u64 pci_io_end_addr;
 	u64 pci_config_addr;
-	u32 dma_mask_bits;
+	u16 dma_mask_bits;
+	u16 dma_noncoherent;
 } __packed;
 
 struct interface_info {
diff --git a/arch/mips/loongson64/env.c b/arch/mips/loongson64/env.c
index c961e2999f15..df0e92cd3920 100644
--- a/arch/mips/loongson64/env.c
+++ b/arch/mips/loongson64/env.c
@@ -13,6 +13,8 @@ 
  * Copyright (C) 2009 Lemote Inc.
  * Author: Wu Zhangjin, wuzhangjin@gmail.com
  */
+
+#include <linux/dma-map-ops.h>
 #include <linux/export.h>
 #include <linux/pci_ids.h>
 #include <asm/bootinfo.h>
@@ -147,8 +149,13 @@  void __init prom_lefi_init_env(void)
 
 	loongson_sysconf.dma_mask_bits = eirq_source->dma_mask_bits;
 	if (loongson_sysconf.dma_mask_bits < 32 ||
-		loongson_sysconf.dma_mask_bits > 64)
+		loongson_sysconf.dma_mask_bits > 64) {
 		loongson_sysconf.dma_mask_bits = 32;
+		dma_default_coherent = true;
+	} else
+		dma_default_coherent = !eirq_source->dma_noncoherent;
+
+	pr_info("DMA coherent: %s\n", dma_default_coherent ? "on" : "off");
 
 	loongson_sysconf.restart_addr = boot_p->reset_system.ResetWarm;
 	loongson_sysconf.poweroff_addr = boot_p->reset_system.Shutdown;