Hi Andrew,
On 24/06/2019 13:03, Andrew Cooper wrote:
On 24/06/2019 12:09, Julien Grall wrote:
(+ GSOC mentors and Andre)
Hi Denis,
Thank you for the patch.
First of all, may I ask to CC the other mentors?
On 6/21/19 9:02 PM, Denis Obrezkov wrote:
This function allows xen to bring secondary CPU cores into non-secure
HYP mode. This is done by using a Secure Monitor call.
Signed-off-by: Denis Obrezkov <denisobrez...@gmail.com>
---
xen/arch/arm/arm32/head.S | 11 ++++++++++-
xen/arch/arm/platforms/omap5.c | 5 +++--
xen/include/asm-arm/platforms/omap5.h | 3 +++
3 files changed, 16 insertions(+), 3 deletions(-)
diff --git a/xen/arch/arm/arm32/head.S b/xen/arch/arm/arm32/head.S
index 5f817d473e..120e034934 100644
--- a/xen/arch/arm/arm32/head.S
+++ b/xen/arch/arm/arm32/head.S
@@ -36,6 +36,10 @@
#include EARLY_PRINTK_INC
#endif
+
+#define API_HYP_ENTRY 0x102
+#define AUX_CORE_BOOT0_PA 0x48281800
+
I have thought a bit more about the placement of the code. I think it would be
best if it lives in a separate file (maybe platforms/omap5-head.S).
For something this trivial, it is easy to put straight into omap5.c
Completely untested, but this ought to work:
diff --git a/xen/arch/arm/platforms/omap5.c b/xen/arch/arm/platforms/omap5.c
index 6b5cc15af3..1dcc92d3a4 100644
--- a/xen/arch/arm/platforms/omap5.c
+++ b/xen/arch/arm/platforms/omap5.c
@@ -23,6 +23,16 @@
#include <xen/vmap.h>
#include <asm/io.h>
+void omap5_init_secondary(void);
+asm (
+".text \n\t"
+"omap5_init_secondary: \n\t"
+" ldr r12, =0x102 \n\t" /* API_HYP_ENTRY */
+" adr r0, init_secondary \n\t"
You cannot use adr on external address for Arm32. This is because the immediate
constant needs to have a specific format (see "Modified immediate constants in
ARM instructions" A5.2.4 in ARM DDI 406C.c).
Instead we would need something like:
omap5_init_secondary:
ldr r12, =0x102
adr r0, omap5_hyp
smc #0
omap5_hyp:
b init_secondary
Note similar code would be needed for the stub file.
+" smc #0 \n\t"
+" b init_secondary \n\t"
+);
+
static uint16_t num_den[8][2] = {
{ 0, 0 }, /* not used */
{ 26 * 64, 26 * 125 }, /* 12.0 Mhz */
I personally find this favourable to introducing new stub files.
Ultimately it is Julien/Stefano's decision, but I'd like to point it out as an
option for anyone who is unaware.
Thank you for the suggestion :). This was suggested last week, but no-one came
back explaining how it could be implemented.
The two are fine with me.
Cheers,
--
Julien Grall
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