[PATCH] drm/i915/gvt: Refine new_mmio_info to override the added MMIO_reg

[Zhao, Yakui]

Hi, 
     Any comment about this patch?
     After the overriding is supported, it can reduce the effect on the other platform when adding one
mmio handle for one specific platform. 

Thanks
     Yakui

>-----Original Message-----
>From: Zhao, Yakui
>Sent: Thursday, May 17, 2018 11:58 AM
>To: intel-gvt-dev at lists.freedesktop.org
>Cc: Zhao, Yakui <yakui.zhao at intel.com>
>Subject: [PATCH] drm/i915/gvt: Refine new_mmio_info to override the added
>MMIO_reg
>
>GVT-g uses new_mmio_info function to track the required the mmio_reg. If
>the required mmio_reg is already added, error is returned. If one platform
>hopes to add new specific MMIO read/write callback for one mmio_reg,  the
>change needs to be applied on all the platforms.
>
>So the new_mmio_info is implemented as override. If it is already added, it
>will be replaced by the new attributes(mask, read/write callback and so on).
>
>Signed-off-by: Zhao Yakui <yakui.zhao at intel.com>
>---
> drivers/gpu/drm/i915/gvt/handlers.c | 25 +++++++++++--------------
> 1 file changed, 11 insertions(+), 14 deletions(-)
>
>diff --git a/drivers/gpu/drm/i915/gvt/handlers.c
>b/drivers/gpu/drm/i915/gvt/handlers.c
>index 653ba2b..a7bf6d5 100644
>--- a/drivers/gpu/drm/i915/gvt/handlers.c
>+++ b/drivers/gpu/drm/i915/gvt/handlers.c
>@@ -107,22 +107,19 @@ static int new_mmio_info(struct intel_gvt *gvt,
> 	end = offset + size;
>
> 	for (i = start; i < end; i += 4) {
>-		info = kzalloc(sizeof(*info), GFP_KERNEL);
>-		if (!info)
>-			return -ENOMEM;
>-
>-		info->offset = i;
>-		p = find_mmio_info(gvt, info->offset);
>+		p = find_mmio_info(gvt, i);
> 		if (p) {
>-			WARN(1, "dup mmio definition offset %x\n",
>-				info->offset);
>-			kfree(info);
>+			/* It will be removed from hash_list if found */
>+			hash_del(&p->node);
>+			info = p;
>+			gvt_dbg_mmio("VGPU MMIO_reg %x is added.
>Override\n",
>+					p->offset);
>+		} else {
>+			info = kzalloc(sizeof(*info), GFP_KERNEL);
>+			if (!info)
>+				return -ENOMEM;
>
>-			/* We return -EEXIST here to make GVT-g load fail.
>-			 * So duplicated MMIO can be found as soon as
>-			 * possible.
>-			 */
>-			return -EEXIST;
>+			info->offset = i;
> 		}
>
> 		info->ro_mask = ro_mask;
>--
>2.7.4