habanalabs: add MMU mappings for Goya CPU

This patch adds the necessary MMU mappings for the Goya CPU to access the
device DRAM and the host memory.

The first 256MB of the device DRAM is being mapped. That's where the F/W
is running.

The 2MB area located on the host memory for the purpose of communication
between the driver and the device CPU is also being mapped.

Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>

2 files changed, 129 insertions, 9 deletions

diff --git a/drivers/misc/habanalabs/goya/goya.c b/drivers/misc/habanalabs/goya/goya.c
index 106074466dca..4e41f2669e6d 100644
--- a/drivers/misc/habanalabs/goya/goya.c
+++ b/drivers/misc/habanalabs/goya/goya.c
@@ -297,6 +297,11 @@ static u32 goya_all_events[] = {
 	GOYA_ASYNC_EVENT_ID_DMA_BM_CH4
 };
 
+static int goya_mmu_clear_pgt_range(struct hl_device *hdev);
+static int goya_mmu_set_dram_default_page(struct hl_device *hdev);
+static int goya_mmu_add_mappings_for_device_cpu(struct hl_device *hdev);
+static void goya_mmu_prepare(struct hl_device *hdev, u32 asid);
+
 void goya_get_fixed_properties(struct hl_device *hdev)
 {
 	struct asic_fixed_properties *prop = &hdev->asic_prop;
@@ -554,6 +559,10 @@ int goya_late_init(struct hl_device *hdev)
 		return rc;
 	}
 
+	rc = goya_mmu_add_mappings_for_device_cpu(hdev);
+	if (rc)
+		return rc;
+
 	rc = goya_init_cpu_queues(hdev);
 	if (rc)
 		return rc;
@@ -2065,10 +2074,12 @@ static void goya_halt_engines(struct hl_device *hdev, bool hard_reset)
 	goya_disable_external_queues(hdev);
 	goya_disable_internal_queues(hdev);
 
-	if (hard_reset)
+	if (hard_reset) {
 		goya_disable_msix(hdev);
-	else
+		goya_mmu_remove_device_cpu_mappings(hdev);
+	} else {
 		goya_sync_irqs(hdev);
+	}
 }
 
 /*
@@ -4584,7 +4595,7 @@ int goya_context_switch(struct hl_device *hdev, u32 asid)
 	return 0;
 }
 
-int goya_mmu_clear_pgt_range(struct hl_device *hdev)
+static int goya_mmu_clear_pgt_range(struct hl_device *hdev)
 {
 	struct asic_fixed_properties *prop = &hdev->asic_prop;
 	struct goya_device *goya = hdev->asic_specific;
@@ -4598,7 +4609,7 @@ int goya_mmu_clear_pgt_range(struct hl_device *hdev)
 	return goya_memset_device_memory(hdev, addr, size, 0, true);
 }
 
-int goya_mmu_set_dram_default_page(struct hl_device *hdev)
+static int goya_mmu_set_dram_default_page(struct hl_device *hdev)
 {
 	struct goya_device *goya = hdev->asic_specific;
 	u64 addr = hdev->asic_prop.mmu_dram_default_page_addr;
@@ -4611,7 +4622,112 @@ int goya_mmu_set_dram_default_page(struct hl_device *hdev)
 	return goya_memset_device_memory(hdev, addr, size, val, true);
 }
 
-void goya_mmu_prepare(struct hl_device *hdev, u32 asid)
+static int goya_mmu_add_mappings_for_device_cpu(struct hl_device *hdev)
+{
+	struct asic_fixed_properties *prop = &hdev->asic_prop;
+	struct goya_device *goya = hdev->asic_specific;
+	s64 off, cpu_off;
+	int rc;
+
+	if (!(goya->hw_cap_initialized & HW_CAP_MMU))
+		return 0;
+
+	for (off = 0 ; off < CPU_FW_IMAGE_SIZE ; off += PAGE_SIZE_2MB) {
+		rc = hl_mmu_map(hdev->kernel_ctx, prop->dram_base_address + off,
+				prop->dram_base_address + off, PAGE_SIZE_2MB);
+		if (rc) {
+			dev_err(hdev->dev, "Map failed for address 0x%llx\n",
+				prop->dram_base_address + off);
+			goto unmap;
+		}
+	}
+
+	if (!(hdev->cpu_accessible_dma_address & (PAGE_SIZE_2MB - 1))) {
+		rc = hl_mmu_map(hdev->kernel_ctx, VA_CPU_ACCESSIBLE_MEM_ADDR,
+			hdev->cpu_accessible_dma_address, PAGE_SIZE_2MB);
+
+		if (rc) {
+			dev_err(hdev->dev,
+				"Map failed for CPU accessible memory\n");
+			off -= PAGE_SIZE_2MB;
+			goto unmap;
+		}
+	} else {
+		for (cpu_off = 0 ; cpu_off < SZ_2M ; cpu_off += PAGE_SIZE_4KB) {
+			rc = hl_mmu_map(hdev->kernel_ctx,
+				VA_CPU_ACCESSIBLE_MEM_ADDR + cpu_off,
+				hdev->cpu_accessible_dma_address + cpu_off,
+				PAGE_SIZE_4KB);
+			if (rc) {
+				dev_err(hdev->dev,
+					"Map failed for CPU accessible memory\n");
+				cpu_off -= PAGE_SIZE_4KB;
+				goto unmap_cpu;
+			}
+		}
+	}
+
+	goya->device_cpu_mmu_mappings_done = true;
+
+	return 0;
+
+unmap_cpu:
+	for (; cpu_off >= 0 ; cpu_off -= PAGE_SIZE_4KB)
+		if (hl_mmu_unmap(hdev->kernel_ctx,
+				VA_CPU_ACCESSIBLE_MEM_ADDR + cpu_off,
+				PAGE_SIZE_4KB))
+			dev_warn_ratelimited(hdev->dev,
+				"failed to unmap address 0x%llx\n",
+				VA_CPU_ACCESSIBLE_MEM_ADDR + cpu_off);
+unmap:
+	for (; off >= 0 ; off -= PAGE_SIZE_2MB)
+		if (hl_mmu_unmap(hdev->kernel_ctx,
+				prop->dram_base_address + off, PAGE_SIZE_2MB))
+			dev_warn_ratelimited(hdev->dev,
+				"failed to unmap address 0x%llx\n",
+				prop->dram_base_address + off);
+
+	return rc;
+}
+
+void goya_mmu_remove_device_cpu_mappings(struct hl_device *hdev)
+{
+	struct asic_fixed_properties *prop = &hdev->asic_prop;
+	struct goya_device *goya = hdev->asic_specific;
+	u32 off, cpu_off;
+
+	if (!(goya->hw_cap_initialized & HW_CAP_MMU))
+		return;
+
+	if (!goya->device_cpu_mmu_mappings_done)
+		return;
+
+	if (!(hdev->cpu_accessible_dma_address & (PAGE_SIZE_2MB - 1))) {
+		if (hl_mmu_unmap(hdev->kernel_ctx, VA_CPU_ACCESSIBLE_MEM_ADDR,
+				PAGE_SIZE_2MB))
+			dev_warn(hdev->dev,
+				"Failed to unmap CPU accessible memory\n");
+	} else {
+		for (cpu_off = 0 ; cpu_off < SZ_2M ; cpu_off += PAGE_SIZE_4KB)
+			if (hl_mmu_unmap(hdev->kernel_ctx,
+					VA_CPU_ACCESSIBLE_MEM_ADDR + cpu_off,
+					PAGE_SIZE_4KB))
+				dev_warn_ratelimited(hdev->dev,
+					"failed to unmap address 0x%llx\n",
+					VA_CPU_ACCESSIBLE_MEM_ADDR + cpu_off);
+	}
+
+	for (off = 0 ; off < CPU_FW_IMAGE_SIZE ; off += PAGE_SIZE_2MB)
+		if (hl_mmu_unmap(hdev->kernel_ctx,
+				prop->dram_base_address + off, PAGE_SIZE_2MB))
+			dev_warn_ratelimited(hdev->dev,
+					"Failed to unmap address 0x%llx\n",
+					prop->dram_base_address + off);
+
+	goya->device_cpu_mmu_mappings_done = false;
+}
+
+static void goya_mmu_prepare(struct hl_device *hdev, u32 asid)
 {
 	struct goya_device *goya = hdev->asic_specific;
 	int i;
diff --git a/drivers/misc/habanalabs/goya/goyaP.h b/drivers/misc/habanalabs/goya/goyaP.h
index 066b1d306977..f8c611883dc1 100644
--- a/drivers/misc/habanalabs/goya/goyaP.h
+++ b/drivers/misc/habanalabs/goya/goyaP.h
@@ -126,6 +126,12 @@
 #define VA_DDR_SPACE_SIZE	(VA_DDR_SPACE_END - \
 					VA_DDR_SPACE_START)	/* 128GB */
 
+#if (HL_CPU_ACCESSIBLE_MEM_SIZE != SZ_2M)
+#error "HL_CPU_ACCESSIBLE_MEM_SIZE must be exactly 2MB to enable MMU mapping"
+#endif
+
+#define VA_CPU_ACCESSIBLE_MEM_ADDR	0x8000000000ull
+
 #define DMA_MAX_TRANSFER_SIZE	U32_MAX
 
 #define HW_CAP_PLL		0x00000001
@@ -157,6 +163,7 @@ struct goya_device {
 	u64		ddr_bar_cur_addr;
 	u32		events_stat[GOYA_ASYNC_EVENT_ID_SIZE];
 	u32		hw_cap_initialized;
+	u8		device_cpu_mmu_mappings_done;
 };
 
 void goya_get_fixed_properties(struct hl_device *hdev);
@@ -204,10 +211,6 @@ int goya_armcp_info_get(struct hl_device *hdev);
 int goya_debug_coresight(struct hl_device *hdev, void *data);
 void goya_halt_coresight(struct hl_device *hdev);
 
-void goya_mmu_prepare(struct hl_device *hdev, u32 asid);
-int goya_mmu_clear_pgt_range(struct hl_device *hdev);
-int goya_mmu_set_dram_default_page(struct hl_device *hdev);
-
 int goya_suspend(struct hl_device *hdev);
 int goya_resume(struct hl_device *hdev);
 
@@ -225,5 +228,6 @@ void *goya_cpu_accessible_dma_pool_alloc(struct hl_device *hdev, size_t size,
 					dma_addr_t *dma_handle);
 void goya_cpu_accessible_dma_pool_free(struct hl_device *hdev, size_t size,
 					void *vaddr);
+void goya_mmu_remove_device_cpu_mappings(struct hl_device *hdev);
 
 #endif /* GOYAP_H_ */