[PATCH 3/8] drm/amdgpu: add amdgpu module parameter for zfb

[Feifei Xu]

Users can pass in an array to decide enable/disable Zero Frame Buffer.
zfb[0] = zfb_size(MB), zfb[1] = zfb_phys_addr(MB).
If zbf_size > 0, zfb is enabled. Otherwise disabled.
Usage for example:
        modprobe amdgpu zfb=256,8192

Change-Id: I711062eb86b6cdff74572cabb3df250c6708e473
Signed-off-by: Feifei Xu <Feifei.Xu at amd.com>
Acked-by: John Bridgman <john.bridgman at amd.com>
Reviewed-by: Alex Deucher <alexander.deucher at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu.h     | 1 +
 drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c | 5 +++++
 2 files changed, 6 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
index 2e6d986..949b451 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
@@ -129,6 +129,7 @@ extern int amdgpu_lbpw;
 extern int amdgpu_compute_multipipe;
 extern int amdgpu_gpu_recovery;
 extern int amdgpu_emu_mode;
+extern ulong amdgpu_zfb[];
 
 #ifdef CONFIG_DRM_AMDGPU_SI
 extern int amdgpu_si_support;
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
index e670936..53ba4ad 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
@@ -132,6 +132,7 @@ int amdgpu_lbpw = -1;
 int amdgpu_compute_multipipe = -1;
 int amdgpu_gpu_recovery = -1; /* auto */
 int amdgpu_emu_mode = 0;
+ulong amdgpu_zfb[2] = {0,4096UL}; /* {0,0x100000000} */
 
 MODULE_PARM_DESC(vramlimit, "Restrict VRAM for testing, in megabytes");
 module_param_named(vramlimit, amdgpu_vram_limit, int, 0600);
@@ -290,6 +291,10 @@ module_param_named(gpu_recovery, amdgpu_gpu_recovery, int, 0444);
 MODULE_PARM_DESC(emu_mode, "Emulation mode, (1 = enable, 0 = disable)");
 module_param_named(emu_mode, amdgpu_emu_mode, int, 0444);
 
+MODULE_PARM_DESC(zfb,
+		 "Enable Zero Frame Buffer feature (zfb will be set like xxxx,xxxx(zfb_size MB,zfb_phys_addr MB),default disabled)");
+module_param_array_named(zfb, amdgpu_zfb, ulong, NULL, 0444);
+
 #ifdef CONFIG_DRM_AMDGPU_SI
 
 #if defined(CONFIG_DRM_RADEON) || defined(CONFIG_DRM_RADEON_MODULE)
-- 
2.7.4