[PATCH v2 17/21] dm: core: Correctly read of simple-bus

Bin Meng
2021-03-12T13:35:58Z

At present we decode simple bus <ranges> using the following assumption:

- parent #address-cells 1
- child #address-cells 1
- child #size-cells 1

However this might not always be the case.

Update to use fdt_addr_t and fdt_size_t in 'struct simple_bus_plat', and
use fdt_read_ranges() to correctly decode it according to the actual
parent and child #address-cells / #size-cells under a Kconfig option
CONFIG_SIMPLE_BUS_CORRECT_RANGE which can be turned on for any board
that needs it.

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

---

Changes in v2:
- include <asm/global_data.h>
- use a Kconfig option CONFIG_SIMPLE_BUS_CORRECT_RANGE to control the
new behavior for boards that want this

drivers/core/Kconfig | 13 +++++++++++++
drivers/core/simple-bus.c | 32 +++++++++++++++++++++++++-------
include/dm/simple_bus.h | 6 +++---
3 files changed, 41 insertions(+), 10 deletions(-)

diff --git a/drivers/core/Kconfig b/drivers/core/Kconfig
index 1eccac28c6..c7504edaf8 100644
--- a/drivers/core/Kconfig
+++ b/drivers/core/Kconfig
@@ -235,6 +235,19 @@ config SPL_SIMPLE_BUS
Supports the 'simple-bus' driver, which is used on some systems
in SPL.

+config SIMPLE_BUS_CORRECT_RANGE
+ bool "Decode the 'simple-bus' <range> by honoring the #address-cells and #size-cells"
+ depends on SIMPLE_BUS
+ help
+ Decoding the 'simple-bus' <range> by honoring the #address-cells
+ and #size-cells of parent/child bus. If unset, #address-cells of
+ parent bus is assumed to be 1, #address-cells and #size-cells of
+ child bus is also assumed to be 1, to save some spaces of using
+ an advanced API to decode the <range>, which benefits SPL image
+ builds that have size limits.
+
+ If you are unsure about this, Say N here.
+
config SIMPLE_PM_BUS
bool "Support simple-pm-bus driver"
depends on DM && OF_CONTROL && CLK && POWER_DOMAIN
diff --git a/drivers/core/simple-bus.c b/drivers/core/simple-bus.c
index b0c2c20958..18f52d26df 100644
--- a/drivers/core/simple-bus.c
+++ b/drivers/core/simple-bus.c
@@ -4,8 +4,12 @@
*/

#include <common.h>
+#include <asm/global_data.h>
#include <dm.h>
#include <dm/simple_bus.h>
+#include <fdt_support.h>
+
+DECLARE_GLOBAL_DATA_PTR;

fdt_addr_t simple_bus_translate(struct udevice *dev, fdt_addr_t addr)
{
@@ -22,16 +26,30 @@ static int simple_bus_post_bind(struct udevice *dev)
#if CONFIG_IS_ENABLED(OF_PLATDATA)
return 0;
#else
- u32 cell[3];
+ struct simple_bus_plat *plat = dev_get_uclass_plat(dev);
int ret;

- ret = dev_read_u32_array(dev, "ranges", cell, ARRAY_SIZE(cell));
- if (!ret) {
- struct simple_bus_plat *plat = dev_get_uclass_plat(dev);
+ if (CONFIG_IS_ENABLED(SIMPLE_BUS_CORRECT_RANGE)) {
+ uint64_t caddr, paddr, len;
+
+ /* only read range index 0 */
+ ret = fdt_read_range((void *)gd->fdt_blob, dev_of_offset(dev),
+ 0, &caddr, &paddr, &len);
+ if (!ret) {
+ plat->base = caddr;
+ plat->target = paddr;
+ plat->size = len;
+ }
+ } else {
+ u32 cell[3];

- plat->base = cell[0];
- plat->target = cell[1];
- plat->size = cell[2];
+ ret = dev_read_u32_array(dev, "ranges", cell,
+ ARRAY_SIZE(cell));
+ if (!ret) {
+ plat->base = cell[0];
+ plat->target = cell[1];
+ plat->size = cell[2];
+ }
}

return dm_scan_fdt_dev(dev);
diff --git a/include/dm/simple_bus.h b/include/dm/simple_bus.h
index 4ad4cc4051..b7104013c0 100644
--- a/include/dm/simple_bus.h
+++ b/include/dm/simple_bus.h
@@ -7,9 +7,9 @@
#define __DM_SIMPLE_BUS_H

struct simple_bus_plat {
- u32 base;
- u32 size;
- u32 target;
+ fdt_addr_t base;
+ fdt_size_t size;
+ fdt_addr_t target;
};

#endif
--
2.25.1