[PATCH v2 19/21] ppc: qemu: Create a virtual memory mapping of the platform bus

Bin Meng
2021-03-12T13:36:00Z

QEMU ppce500 target can dynamically instantiate an eTSEC device on
a platform bus if "-device eTSEC" is given to QEMU. It is presented
as a "simple-bus" in the device tree, with an additional compatible
string "qemu,platform".

Let's create a virtual memory mapping for it in misc_init_r(), in
preparation to adding eTSEC support.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>

---

Changes in v2:
- turn on CONFIG_SIMPLE_BUS_CORRECT_RANGE in qemu-ppce500_defconfig

board/emulation/qemu-ppce500/Kconfig | 6 ++++++
board/emulation/qemu-ppce500/qemu-ppce500.c | 18 ++++++++++++++++++
configs/qemu-ppce500_defconfig | 1 +
3 files changed, 25 insertions(+)

diff --git a/board/emulation/qemu-ppce500/Kconfig b/board/emulation/qemu-ppce500/Kconfig
index 4312d986d8..1c5aa18aa9 100644
--- a/board/emulation/qemu-ppce500/Kconfig
+++ b/board/emulation/qemu-ppce500/Kconfig
@@ -9,4 +9,10 @@ config SYS_VENDOR
config SYS_CONFIG_NAME
default "qemu-ppce500"

+config PLATFORM_BUS_MAP_ADDR
+ hex
+ default 0xf0000000
+ help
+ The QEMU platform bus base mapped address in the virtual memory space.
+
endif
diff --git a/board/emulation/qemu-ppce500/qemu-ppce500.c b/board/emulation/qemu-ppce500/qemu-ppce500.c
index daa103c564..0960dd1f97 100644
--- a/board/emulation/qemu-ppce500/qemu-ppce500.c
+++ b/board/emulation/qemu-ppce500/qemu-ppce500.c
@@ -14,6 +14,8 @@
#include <net.h>
#include <pci.h>
#include <time.h>
+#include <dm/simple_bus.h>
+#include <dm/uclass-internal.h>
#include <asm/global_data.h>
#include <asm/processor.h>
#include <asm/mmu.h>
@@ -148,6 +150,22 @@ int misc_init_r(void)
*/
disable_tlb(find_tlb_idx((void *)CONFIG_SYS_TMPVIRT, 1));

+ /*
+ * Detect the presence of the platform bus node, and
+ * create a virtual memory mapping for it.
+ */
+ for (ret = uclass_find_first_device(UCLASS_SIMPLE_BUS, &dev);
+ dev;
+ ret = uclass_find_next_device(&dev)) {
+ if (device_is_compatible(dev, "qemu,platform")) {
+ struct simple_bus_plat *plat = dev_get_uclass_plat(dev);
+
+ assert(!tlb_map_range(CONFIG_PLATFORM_BUS_MAP_ADDR,
+ plat->target, plat->size,
+ TLB_MAP_IO));
+ }
+ }
+
return 0;
}

diff --git a/configs/qemu-ppce500_defconfig b/configs/qemu-ppce500_defconfig
index 536fe7d6e1..151834b4cf 100644
--- a/configs/qemu-ppce500_defconfig
+++ b/configs/qemu-ppce500_defconfig
@@ -28,6 +28,7 @@ CONFIG_OF_BOARD=y
CONFIG_ENV_OVERWRITE=y
CONFIG_SYS_RELOC_GD_ENV_ADDR=y
CONFIG_DM=y
+CONFIG_SIMPLE_BUS_CORRECT_RANGE=y
CONFIG_BLK=y
CONFIG_HAVE_BLOCK_DEVICE=y
CONFIG_MPC8XXX_GPIO=y
--
2.25.1