Nouveau - Sep 2016 - [PATCH] volt: use kernel's 64-bit signed division function

Doing direct 64 bit divisions in kernel code leads to references to
undefined symbols on 32 bit architectures. Replace such divisions with
calls to div64_s64 to make the module usable on 32 bit archs.

Signed-off-by: Alexandre Courbot <acourbot at nvidia.com>
---
 drm/nouveau/nvkm/subdev/volt/base.c | 6 +++---
 lib/include/nvif/os.h               | 1 +
 2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/drm/nouveau/nvkm/subdev/volt/base.c
b/drm/nouveau/nvkm/subdev/volt/base.c
index 90d234231eed..e8569b04b55d 100644
--- a/drm/nouveau/nvkm/subdev/volt/base.c
+++ b/drm/nouveau/nvkm/subdev/volt/base.c
@@ -116,9 +116,9 @@ nvkm_volt_map(struct nvkm_volt *volt, u8 id, u8 temp)
 			return volt->speedo;
 
 		if (ver == 0x10 || (ver == 0x20 && info.mode == 0)) {
-			result  =  (s64)info.arg[0] / 10;
-			result += ((s64)info.arg[1] * volt->speedo) / 10;
-			result += ((s64)info.arg[2] * volt->speedo * volt->speedo) / 100000;
+			result  = div64_s64((s64)info.arg[0], 10);
+			result += div64_s64((s64)info.arg[1] * volt->speedo, 10);
+			result += div64_s64((s64)info.arg[2] * volt->speedo * volt->speedo,
100000);
 		} else if (ver == 0x20) {
 			switch (info.mode) {
 			/* 0x0 handled above! */
diff --git a/lib/include/nvif/os.h b/lib/include/nvif/os.h
index b45a1862436e..2c1985d90474 100644
--- a/lib/include/nvif/os.h
+++ b/lib/include/nvif/os.h
@@ -88,6 +88,7 @@ typedef dma_addr_t resource_size_t;
 )
 #define do_div(a,b) (a) = (a) / (b)
 #define div_u64(a,b) (a) / (b)
+#define div64_s64(a,b) (a) / (b)
 #define likely(a) (a)
 #define unlikely(a) (a)
 #define BIT(a) (1UL << (a))
-- 
2.9.3

yeah locks fine

Reviewed-by: Karol Herbst <karolherbst at gmail.com>

2016-09-16 11:09 GMT+02:00 Alexandre Courbot <acourbot at
nvidia.com>:
> Doing direct 64 bit divisions in kernel code leads to references to
> undefined symbols on 32 bit architectures. Replace such divisions with
> calls to div64_s64 to make the module usable on 32 bit archs.
>
> Signed-off-by: Alexandre Courbot <acourbot at nvidia.com>
> ---
>  drm/nouveau/nvkm/subdev/volt/base.c | 6 +++---
>  lib/include/nvif/os.h               | 1 +
>  2 files changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/drm/nouveau/nvkm/subdev/volt/base.c
b/drm/nouveau/nvkm/subdev/volt/base.c
> index 90d234231eed..e8569b04b55d 100644
> --- a/drm/nouveau/nvkm/subdev/volt/base.c
> +++ b/drm/nouveau/nvkm/subdev/volt/base.c
> @@ -116,9 +116,9 @@ nvkm_volt_map(struct nvkm_volt *volt, u8 id, u8 temp)
>                         return volt->speedo;
>
>                 if (ver == 0x10 || (ver == 0x20 && info.mode == 0))
{
> -                       result  =  (s64)info.arg[0] / 10;
> -                       result += ((s64)info.arg[1] * volt->speedo) /
10;
> -                       result += ((s64)info.arg[2] * volt->speedo *
volt->speedo) / 100000;
> +                       result  = div64_s64((s64)info.arg[0], 10);
> +                       result += div64_s64((s64)info.arg[1] *
volt->speedo, 10);
> +                       result += div64_s64((s64)info.arg[2] *
volt->speedo * volt->speedo, 100000);
>                 } else if (ver == 0x20) {
>                         switch (info.mode) {
>                         /* 0x0 handled above! */
> diff --git a/lib/include/nvif/os.h b/lib/include/nvif/os.h
> index b45a1862436e..2c1985d90474 100644
> --- a/lib/include/nvif/os.h
> +++ b/lib/include/nvif/os.h
> @@ -88,6 +88,7 @@ typedef dma_addr_t resource_size_t;
>  )
>  #define do_div(a,b) (a) = (a) / (b)
>  #define div_u64(a,b) (a) / (b)
> +#define div64_s64(a,b) (a) / (b)
>  #define likely(a) (a)
>  #define unlikely(a) (a)
>  #define BIT(a) (1UL << (a))
> --
> 2.9.3
>