On Thu, May 10, 2018 at 6:09 PM, Marek Vasut marex@denx.de wrote:
On 05/10/2018 10:45 AM, Ley Foon Tan wrote:
On Tue, May 8, 2018 at 5:21 PM, Marek Vasut marex@denx.de wrote:
On 05/08/2018 08:49 AM, Ley Foon Tan wrote:
On Thu, Apr 19, 2018 at 10:53 AM, Marek Vasut marex@denx.de wrote:
On 04/19/2018 11:50 AM, Ley Foon Tan wrote:
Add mailbox support for Stratix SoC
Signed-off-by: Ley Foon Tan ley.foon.tan@intel.com Signed-off-by: Chin Liang See chin.liang.see@intel.com
[...]
+static __always_inline int mbox_polling_resp(u32 rout) +{
static const struct socfpga_mailbox *mbox_base =(void *)SOCFPGA_MAILBOX_ADDRESS;u32 rin;unsigned long i = ~0;while (i) {rin = readl(&mbox_base->rin);if (rout != rin)return 0;This looks like include/wait_bit.h reimplementation
The reason we use this method instead of using wait_bit because this function will use in Secure Monitor Call (SMC) call as well. When run in secure section, timer is not available. So, we can't use wait_for_bit.
Can't you just do timer_init() then ?
We can't use timer in secure region. This SMC code is resident in onchip memory (secure region) while Linux is running. So, timer might be used by Linux.
So pieces of U-Boot remain in memory and get called by Linux, right ?
Normal U-boot (in DDR) is destroyed after Linux is running, only SMC code Onchip memory will remain. The existing U-boot have support this SMC feature, platform just need to configure the CONFIG_ARMV8_SECURE_BASE for the secure section. Of course, we need to enable CONFIG_ARMV8_PSCI too.
I am CCing a few more people , since this might need further discussion.
btw does this work when Linux is compiled in AArch32 mode while U-Boot is AArch64 ? I think it might not.
It should work. PSCI handle checks ESR_EL3.EC field to know whether it is SMC32 or SMC64. See code in handle_sync near line 230 in http://git.denx.de/?p=u-boot.git;a=blob;f=arch/arm/cpu/armv8/psci.S
+/* Send command only without waiting for responses from SDM */ +static __always_inline int __mbox_send_cmd_only(u8 id, u32 cmd,
u8 is_indirect, u32 len,u32 *arg)+{
int ret = mbox_prepare_cmd_only(id, cmd, is_indirect, len, arg);/* write doorbell */writel(1, MBOX_DOORBELL_TO_SDM_REG);return ret;+}
+/* Return number of responses received in buffer */ +static __always_inline int __mbox_rcv_resp(u32 *resp_buf, u32 resp_buf_max_len)
__always_inline is nonsense, drop it. Let the compiler do it's thing.
This function used in SMC call as well, so it needs to be inline when in secure section.
Why ?
These functions needed for normal U-boot and SMC (secure section in OCM) and we need to copy the whole function to secure section, not just the API call. This also avoid code duplication for U-boot and SMC.
Thanks for the explanation!
--
Regards Ley Foon