On 15.07.19 18:42, Andrew Jones wrote:
On Fri, Jul 12, 2019 at 11:19:38AM +0200, Alexander Graf wrote:
This patch adds a unit test for the PL031 RTC that is used in the virt machine.
It just pokes basic functionality. I've mostly written it to familiarize myself
with the device, but I suppose having the test around does not hurt, as it also
exercises the GIC SPI interrupt path.
Signed-off-by: Alexander Graf <graf@xxxxxxxxxx>
---
v1 -> v2:
- Use FDT to find base, irq and existence
- Put isb after timer read
- Use dist_base for gicv3
---
arm/Makefile.common | 1 +
arm/pl031.c | 265 ++++++++++++++++++++++++++++++++++++++++++++
lib/arm/asm/gic.h | 1 +
3 files changed, 267 insertions(+)
create mode 100644 arm/pl031.c
diff --git a/arm/Makefile.common b/arm/Makefile.common
index f0c4b5d..b8988f2 100644
--- a/arm/Makefile.common
+++ b/arm/Makefile.common
@@ -11,6 +11,7 @@ tests-common += $(TEST_DIR)/pmu.flat
tests-common += $(TEST_DIR)/gic.flat
tests-common += $(TEST_DIR)/psci.flat
tests-common += $(TEST_DIR)/sieve.flat
+tests-common += $(TEST_DIR)/pl031.flat
Makefile.common is for both arm32 and arm64, but this code is only
compilable on arm64. As there's no reason for it to be arm64 only,
then ideally we'd modify the code to allow compiling and running
on both, but otherwise we need to move this to Makefile.arm64.
D'oh. Sorry, I completely missed that bit. Of course we want to test on
32bit ARM as well! I'll fix it up :).
[...]
+static int rtc_fdt_init(void)
+{
+ const struct fdt_property *prop;
+ const void *fdt = dt_fdt();
+ int node, len;
+ u32 *data;
+
+ node = fdt_node_offset_by_compatible(fdt, -1, "arm,pl031");
+ if (node < 0)
+ return -1;
+
+ prop = fdt_get_property(fdt, node, "interrupts", &len);
+ assert(prop && len == (3 * sizeof(u32)));
+ data = (u32 *)prop->data;
+ assert(data[0] == 0); /* SPI */
+ pl031_irq = SPI(fdt32_to_cpu(data[1]));
Nit: Ideally we'd add some more devicetree API to get interrupts. With
that, and the existing devicetree API, we could remove all low-level fdt
related code in this function.
Well, we probably want some really high level fdt API that can traverse
reg properly to map bus regs into physical addresses. As long as we
don't have all that magic, I see little point in inventing anything that
looks more sophisticated but doesn't actually take the difficult
problems into account :).
+
+ prop = fdt_get_property(fdt, node, "reg", &len);
+ assert(prop && len == (2 * sizeof(u64)));
+ data = (u32 *)prop->data;
+ pl031 = (void*)((ulong)fdt32_to_cpu(data[0]) << 32 | fdt32_to_cpu(data[1]));
This works because we currently ID map all the physical memory. I usually
try to remember to use an ioremap in these cases anyway though.
Great idea - it allows me to get rid of a bit of casting too.
Alex
