drm/amdgpu: SR-IOV data exchange between PF&VF

SR-IOV need to exchange some data between PF&VF through shared VRAM

PF will copy some necessary firmware and information to the shared
VRAM. It also requires some information from VF. PF will send a
key through mailbox2 to help guest calculate checksum so that it can
verify whether the data is correct.

So check the data on the specified offset of the shared VRAM, if the
checksum is right, read values from it and write some VF information
next to the data from PF.

Signed-off-by: Horace Chen <horace.chen@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 75 insertions, 0 deletions

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_virt.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_virt.c
index ab05121b9272..ed7be2eb24b0 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_virt.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_virt.c
@@ -274,3 +274,78 @@ void amdgpu_virt_free_mm_table(struct amdgpu_device *adev)
 			      (void *)&adev->virt.mm_table.cpu_addr);
 	adev->virt.mm_table.gpu_addr = 0;
 }
+
+
+int amdgpu_virt_fw_reserve_get_checksum(void *obj,
+					unsigned long obj_size,
+					unsigned int key,
+					unsigned int chksum)
+{
+	unsigned int ret = key;
+	unsigned long i = 0;
+	unsigned char *pos;
+
+	pos = (char *)obj;
+	/* calculate checksum */
+	for (i = 0; i < obj_size; ++i)
+		ret += *(pos + i);
+	/* minus the chksum itself */
+	pos = (char *)&chksum;
+	for (i = 0; i < sizeof(chksum); ++i)
+		ret -= *(pos + i);
+	return ret;
+}
+
+void amdgpu_virt_init_data_exchange(struct amdgpu_device *adev)
+{
+	uint32_t pf2vf_ver = 0;
+	uint32_t pf2vf_size = 0;
+	uint32_t checksum = 0;
+	uint32_t checkval;
+	char *str;
+
+	adev->virt.fw_reserve.p_pf2vf = NULL;
+	adev->virt.fw_reserve.p_vf2pf = NULL;
+
+	if (adev->fw_vram_usage.va != NULL) {
+		adev->virt.fw_reserve.p_pf2vf =
+			(struct amdgim_pf2vf_info_header *)(
+			adev->fw_vram_usage.va + AMDGIM_DATAEXCHANGE_OFFSET);
+		pf2vf_ver = adev->virt.fw_reserve.p_pf2vf->version;
+		AMDGPU_FW_VRAM_PF2VF_READ(adev, header.size, &pf2vf_size);
+		AMDGPU_FW_VRAM_PF2VF_READ(adev, checksum, &checksum);
+
+		/* pf2vf message must be in 4K */
+		if (pf2vf_size > 0 && pf2vf_size < 4096) {
+			checkval = amdgpu_virt_fw_reserve_get_checksum(
+				adev->virt.fw_reserve.p_pf2vf, pf2vf_size,
+				adev->virt.fw_reserve.checksum_key, checksum);
+			if (checkval == checksum) {
+				adev->virt.fw_reserve.p_vf2pf =
+					((void *)adev->virt.fw_reserve.p_pf2vf +
+					pf2vf_size);
+				memset((void *)adev->virt.fw_reserve.p_vf2pf, 0,
+					sizeof(amdgim_vf2pf_info));
+				AMDGPU_FW_VRAM_VF2PF_WRITE(adev, header.version,
+					AMDGPU_FW_VRAM_VF2PF_VER);
+				AMDGPU_FW_VRAM_VF2PF_WRITE(adev, header.size,
+					sizeof(amdgim_vf2pf_info));
+				AMDGPU_FW_VRAM_VF2PF_READ(adev, driver_version,
+					&str);
+				if (THIS_MODULE->version != NULL)
+					strcpy(str, THIS_MODULE->version);
+				else
+					strcpy(str, "N/A");
+				AMDGPU_FW_VRAM_VF2PF_WRITE(adev, driver_cert,
+					0);
+				AMDGPU_FW_VRAM_VF2PF_WRITE(adev, checksum,
+					amdgpu_virt_fw_reserve_get_checksum(
+					adev->virt.fw_reserve.p_vf2pf,
+					pf2vf_size,
+					adev->virt.fw_reserve.checksum_key, 0));
+			}
+		}
+	}
+}
+
+