* Re: [PATCH] drm/i915/gvt: Use ARRAY_SIZE instead of hardcoded size
2020-04-13 14:32 [PATCH] drm/i915/gvt: Use ARRAY_SIZE instead of hardcoded size Jason Yan
@ 2020-04-13 17:55 ` Joe Perches
0 siblings, 0 replies; 2+ messages in thread
From: Joe Perches @ 2020-04-13 17:55 UTC (permalink / raw)
To: Jason Yan, zhenyuw, zhi.a.wang, jani.nikula, joonas.lahtinen,
rodrigo.vivi, airlied, daniel, intel-gvt-dev, intel-gfx,
dri-devel, linux-kernel
On Mon, 2020-04-13 at 22:32 +0800, Jason Yan wrote:
> Fix the following coccicheck warning:
>
> drivers/gpu/drm/i915/gvt/vgpu.c:127:30-31: WARNING: Use ARRAY_SIZE
>
> Signed-off-by: Jason Yan <yanaijie@huawei.com>
> ---
> drivers/gpu/drm/i915/gvt/vgpu.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/i915/gvt/vgpu.c b/drivers/gpu/drm/i915/gvt/vgpu.c
> index 1d5ff88078bd..7d361623ff67 100644
> --- a/drivers/gpu/drm/i915/gvt/vgpu.c
> +++ b/drivers/gpu/drm/i915/gvt/vgpu.c
> @@ -124,7 +124,7 @@ int intel_gvt_init_vgpu_types(struct intel_gvt *gvt)
> */
> low_avail = gvt_aperture_sz(gvt) - HOST_LOW_GM_SIZE;
> high_avail = gvt_hidden_sz(gvt) - HOST_HIGH_GM_SIZE;
> - num_types = sizeof(vgpu_types) / sizeof(vgpu_types[0]);
> + num_types = ARRAY_SIZE(vgpu_types);
>
> gvt->types = kcalloc(num_types, sizeof(struct intel_vgpu_type),
> GFP_KERNEL);
It's probably better to remove num_types altogether and just
use ARRAY_SIZE in both places num_types is used.
Perhaps refactoring the function a bit more is also better.
Perhaps:
o Use ARRAY_SIZE
o Make vgpu_types static const to reduce data size and
move the definition into the function where it's used
o Use temporaries to shorten the code indirections.
---
drivers/gpu/drm/i915/gvt/vgpu.c | 92 +++++++++++++++++++++--------------------
1 file changed, 47 insertions(+), 45 deletions(-)
diff --git a/drivers/gpu/drm/i915/gvt/vgpu.c b/drivers/gpu/drm/i915/gvt/vgpu.c
index 1d5ff8..e56f59d 100644
--- a/drivers/gpu/drm/i915/gvt/vgpu.c
+++ b/drivers/gpu/drm/i915/gvt/vgpu.c
@@ -77,26 +77,6 @@ void populate_pvinfo_page(struct intel_vgpu *vgpu)
#define VGPU_WEIGHT(vgpu_num) \
(VGPU_MAX_WEIGHT / (vgpu_num))
-static struct {
- unsigned int low_mm;
- unsigned int high_mm;
- unsigned int fence;
-
- /* A vGPU with a weight of 8 will get twice as much GPU as a vGPU
- * with a weight of 4 on a contended host, different vGPU type has
- * different weight set. Legal weights range from 1 to 16.
- */
- unsigned int weight;
- enum intel_vgpu_edid edid;
- char *name;
-} vgpu_types[] = {
-/* Fixed vGPU type table */
- { MB_TO_BYTES(64), MB_TO_BYTES(384), 4, VGPU_WEIGHT(8), GVT_EDID_1024_768, "8" },
- { MB_TO_BYTES(128), MB_TO_BYTES(512), 4, VGPU_WEIGHT(4), GVT_EDID_1920_1200, "4" },
- { MB_TO_BYTES(256), MB_TO_BYTES(1024), 4, VGPU_WEIGHT(2), GVT_EDID_1920_1200, "2" },
- { MB_TO_BYTES(512), MB_TO_BYTES(2048), 4, VGPU_WEIGHT(1), GVT_EDID_1920_1200, "1" },
-};
-
/**
* intel_gvt_init_vgpu_types - initialize vGPU type list
* @gvt : GVT device
@@ -106,9 +86,32 @@ static struct {
*/
int intel_gvt_init_vgpu_types(struct intel_gvt *gvt)
{
- unsigned int num_types;
unsigned int i, low_avail, high_avail;
unsigned int min_low;
+ static const struct vgpu_types {
+ unsigned int low_mm;
+ unsigned int high_mm;
+ unsigned int fence;
+
+ /* A vGPU with a weight of 8 will get twice as much GPU
+ * as a vGPU with a weight of 4 on a contended host,
+ * different vGPU type has different weight set.
+ * Legal weights range from 1 to 16.
+ */
+ unsigned int weight;
+ enum intel_vgpu_edid edid;
+ char *name;
+ } vgpu_types[] = {
+ /* Fixed vGPU type table */
+ { MB_TO_BYTES(64), MB_TO_BYTES(384), 4,
+ VGPU_WEIGHT(8), GVT_EDID_1024_768, "8" },
+ { MB_TO_BYTES(128), MB_TO_BYTES(512), 4,
+ VGPU_WEIGHT(4), GVT_EDID_1920_1200, "4" },
+ { MB_TO_BYTES(256), MB_TO_BYTES(1024), 4,
+ VGPU_WEIGHT(2), GVT_EDID_1920_1200, "2" },
+ { MB_TO_BYTES(512), MB_TO_BYTES(2048), 4,
+ VGPU_WEIGHT(1), GVT_EDID_1920_1200, "1" },
+ };
/* vGPU type name is defined as GVTg_Vx_y which contains
* physical GPU generation type (e.g V4 as BDW server, V5 as
@@ -124,45 +127,44 @@ int intel_gvt_init_vgpu_types(struct intel_gvt *gvt)
*/
low_avail = gvt_aperture_sz(gvt) - HOST_LOW_GM_SIZE;
high_avail = gvt_hidden_sz(gvt) - HOST_HIGH_GM_SIZE;
- num_types = sizeof(vgpu_types) / sizeof(vgpu_types[0]);
- gvt->types = kcalloc(num_types, sizeof(struct intel_vgpu_type),
- GFP_KERNEL);
+ gvt->types = kcalloc(ARRAY_SIZE(vgpu_types),
+ sizeof(struct intel_vgpu_type), GFP_KERNEL);
if (!gvt->types)
return -ENOMEM;
min_low = MB_TO_BYTES(32);
- for (i = 0; i < num_types; ++i) {
- if (low_avail / vgpu_types[i].low_mm == 0)
+ for (i = 0; i < ARRAY_SIZE(vgpu_types); i++) {
+ struct intel_vgpu_type *type = &gvt->types[i];
+ const struct vgpu_types *vgpu = &vgpu_types[i];
+
+ if (low_avail / vgpu->low_mm == 0)
break;
- gvt->types[i].low_gm_size = vgpu_types[i].low_mm;
- gvt->types[i].high_gm_size = vgpu_types[i].high_mm;
- gvt->types[i].fence = vgpu_types[i].fence;
+ type->low_gm_size = vgpu->low_mm;
+ type->high_gm_size = vgpu->high_mm;
+ type->fence = vgpu->fence;
- if (vgpu_types[i].weight < 1 ||
- vgpu_types[i].weight > VGPU_MAX_WEIGHT)
+ if (vgpu->weight < 1 || vgpu->weight > VGPU_MAX_WEIGHT)
return -EINVAL;
- gvt->types[i].weight = vgpu_types[i].weight;
- gvt->types[i].resolution = vgpu_types[i].edid;
- gvt->types[i].avail_instance = min(low_avail / vgpu_types[i].low_mm,
- high_avail / vgpu_types[i].high_mm);
+ type->weight = vgpu->weight;
+ type->resolution = vgpu->edid;
+ type->avail_instance = min(low_avail / vgpu->low_mm,
+ high_avail / vgpu->high_mm);
if (IS_GEN(gvt->gt->i915, 8))
- sprintf(gvt->types[i].name, "GVTg_V4_%s",
- vgpu_types[i].name);
+ sprintf(type->name, "GVTg_V4_%s", vgpu->name);
else if (IS_GEN(gvt->gt->i915, 9))
- sprintf(gvt->types[i].name, "GVTg_V5_%s",
- vgpu_types[i].name);
+ sprintf(type->name, "GVTg_V5_%s", vgpu->name);
gvt_dbg_core("type[%d]: %s avail %u low %u high %u fence %u weight %u res %s\n",
- i, gvt->types[i].name,
- gvt->types[i].avail_instance,
- gvt->types[i].low_gm_size,
- gvt->types[i].high_gm_size, gvt->types[i].fence,
- gvt->types[i].weight,
- vgpu_edid_str(gvt->types[i].resolution));
+ i, type->name,
+ type->avail_instance,
+ type->low_gm_size,
+ type->high_gm_size, type->fence,
+ type->weight,
+ vgpu_edid_str(type->resolution));
}
gvt->num_types = i;
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