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path: root/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_vmid.c
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Diffstat (limited to 'drivers/gpu/drm/amd/display/dc/dcn20/dcn20_vmid.c')
-rw-r--r--drivers/gpu/drm/amd/display/dc/dcn20/dcn20_vmid.c37
1 files changed, 37 insertions, 0 deletions
diff --git a/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_vmid.c b/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_vmid.c
index 27679ef6ebe8..96c263223315 100644
--- a/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_vmid.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_vmid.c
@@ -23,6 +23,8 @@
*
*/
+#include <linux/delay.h>
+
#include "dcn20_vmid.h"
#include "reg_helper.h"
@@ -36,6 +38,38 @@
#define FN(reg_name, field_name) \
vmid->shifts->field_name, vmid->masks->field_name
+static void dcn20_wait_for_vmid_ready(struct dcn20_vmid *vmid)
+{
+ /* According the hardware spec, we need to poll for the lowest
+ * bit of PAGE_TABLE_BASE_ADDR_LO32 = 1 any time a GPUVM
+ * context is updated. We can't use REG_WAIT here since we
+ * don't have a seperate field to wait on.
+ *
+ * TODO: Confirm timeout / poll interval with hardware team
+ */
+
+ int max_times = 10000;
+ int delay_us = 5;
+ int i;
+
+ for (i = 0; i < max_times; ++i) {
+ uint32_t entry_lo32;
+
+ REG_GET(PAGE_TABLE_BASE_ADDR_LO32,
+ VM_CONTEXT0_PAGE_DIRECTORY_ENTRY_LO32,
+ &entry_lo32);
+
+ if (entry_lo32 & 0x1)
+ return;
+
+ udelay(delay_us);
+ }
+
+ /* VM setup timed out */
+ DC_LOG_WARNING("Timeout while waiting for GPUVM context update\n");
+ ASSERT(0);
+}
+
void dcn20_vmid_setup(struct dcn20_vmid *vmid, const struct dcn_vmid_page_table_config *config)
{
REG_SET(PAGE_TABLE_START_ADDR_HI32, 0,
@@ -54,6 +88,9 @@ void dcn20_vmid_setup(struct dcn20_vmid *vmid, const struct dcn_vmid_page_table_
REG_SET(PAGE_TABLE_BASE_ADDR_HI32, 0,
VM_CONTEXT0_PAGE_DIRECTORY_ENTRY_HI32, (config->page_table_base_addr >> 32) & 0xFFFFFFFF);
+ /* Note: per hardware spec PAGE_TABLE_BASE_ADDR_LO32 must be programmed last in sequence */
REG_SET(PAGE_TABLE_BASE_ADDR_LO32, 0,
VM_CONTEXT0_PAGE_DIRECTORY_ENTRY_LO32, config->page_table_base_addr & 0xFFFFFFFF);
+
+ dcn20_wait_for_vmid_ready(vmid);
}