| Message ID | 1371114745-24710-4-git-send-email-acourbot@nvidia.com |
|---|---|
| State | Superseded, archived |
| Headers | show |
On 06/13/2013 03:12 AM, Alexandre Courbot wrote: > Use a firmware operation to set the CPU reset handler and only resort to > doing it ourselves if there is none defined. > > This supports the booting of secondary CPUs on devices using a TrustZone > secure monitor. > diff --git a/arch/arm/mach-tegra/reset.c b/arch/arm/mach-tegra/reset.c > + err = call_firmware_op(set_cpu_boot_addr, 0, reset_address); > + switch (err) { > + case -ENOSYS: > + tegra_cpu_reset_handler_set(reset_address); > + /* pass-through */ Rather than detecting -ENOSYS and falling back to the custom tegra_cpu_reset_handler_set(), does it make sense to plug in tegra_cpu_reset_handler_set as the firmware op when there is no secure firmware detected? That way, this code wouldn't need the special case; that would be isolated to firmware.c. -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Fri, Jun 14, 2013 at 4:23 AM, Stephen Warren <swarren@wwwdotorg.org> wrote: > On 06/13/2013 03:12 AM, Alexandre Courbot wrote: >> Use a firmware operation to set the CPU reset handler and only resort to >> doing it ourselves if there is none defined. >> >> This supports the booting of secondary CPUs on devices using a TrustZone >> secure monitor. > >> diff --git a/arch/arm/mach-tegra/reset.c b/arch/arm/mach-tegra/reset.c > >> + err = call_firmware_op(set_cpu_boot_addr, 0, reset_address); >> + switch (err) { >> + case -ENOSYS: >> + tegra_cpu_reset_handler_set(reset_address); >> + /* pass-through */ > > Rather than detecting -ENOSYS and falling back to the custom > tegra_cpu_reset_handler_set(), does it make sense to plug in > tegra_cpu_reset_handler_set as the firmware op when there is no secure > firmware detected? That way, this code wouldn't need the special case; > that would be isolated to firmware.c. Mmmm I admit I just followed what Exynos did without thinking much about it. I don't see any reason why your suggestion wouldn't work, but on second thought tegra_cpu_reset_handler_set() is not a firmware operation - wouldn't it be unexpected (and maybe confusing) to have it called through call_firmware_op()? Alex. -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 06/14/2013 02:54 AM, Alexandre Courbot wrote: > On Fri, Jun 14, 2013 at 4:23 AM, Stephen Warren <swarren@wwwdotorg.org> wrote: >> On 06/13/2013 03:12 AM, Alexandre Courbot wrote: >>> Use a firmware operation to set the CPU reset handler and only resort to >>> doing it ourselves if there is none defined. >>> >>> This supports the booting of secondary CPUs on devices using a TrustZone >>> secure monitor. >> >>> diff --git a/arch/arm/mach-tegra/reset.c b/arch/arm/mach-tegra/reset.c >> >>> + err = call_firmware_op(set_cpu_boot_addr, 0, reset_address); >>> + switch (err) { >>> + case -ENOSYS: >>> + tegra_cpu_reset_handler_set(reset_address); >>> + /* pass-through */ >> >> Rather than detecting -ENOSYS and falling back to the custom >> tegra_cpu_reset_handler_set(), does it make sense to plug in >> tegra_cpu_reset_handler_set as the firmware op when there is no secure >> firmware detected? That way, this code wouldn't need the special case; >> that would be isolated to firmware.c. > > Mmmm I admit I just followed what Exynos did without thinking much > about it. I don't see any reason why your suggestion wouldn't work, > but on second thought tegra_cpu_reset_handler_set() is not a firmware > operation - wouldn't it be unexpected (and maybe confusing) to have it > called through call_firmware_op()? I would see call_firmware_op() as an abstraction that performs certain operations, which in some cases are performed by firmware. If the operation doesn't actually need to call into firmware in some situations, that seems fine to me. But you're right, others may object. Perhaps get a ruling from whoever created firmware_ops and/or some main ARM maintainers. -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/arch/arm/mach-tegra/reset.c b/arch/arm/mach-tegra/reset.c index 6964117..40f110c 100644 --- a/arch/arm/mach-tegra/reset.c +++ b/arch/arm/mach-tegra/reset.c @@ -21,6 +21,7 @@ #include <asm/cacheflush.h> #include <asm/hardware/cache-l2x0.h> +#include <asm/firmware.h> #include "iomap.h" #include "irammap.h" @@ -65,6 +66,7 @@ static void __init tegra_cpu_reset_handler_enable(void) void __iomem *iram_base = IO_ADDRESS(TEGRA_IRAM_RESET_BASE); const u32 reset_address = TEGRA_IRAM_RESET_BASE + tegra_cpu_reset_handler_offset; + int err; BUG_ON(is_enabled); BUG_ON(tegra_cpu_reset_handler_size > TEGRA_IRAM_RESET_HANDLER_SIZE); @@ -72,9 +74,18 @@ static void __init tegra_cpu_reset_handler_enable(void) memcpy(iram_base, (void *)__tegra_cpu_reset_handler_start, tegra_cpu_reset_handler_size); - tegra_cpu_reset_handler_set(reset_address); - - is_enabled = true; + err = call_firmware_op(set_cpu_boot_addr, 0, reset_address); + switch (err) { + case -ENOSYS: + tegra_cpu_reset_handler_set(reset_address); + /* pass-through */ + case 0: + is_enabled = true; + break; + default: + pr_err("Cannot set CPU reset handler: %d\n", err); + break; + } } void __init tegra_cpu_reset_handler_init(void)
Use a firmware operation to set the CPU reset handler and only resort to doing it ourselves if there is none defined. This supports the booting of secondary CPUs on devices using a TrustZone secure monitor. Signed-off-by: Alexandre Courbot <acourbot@nvidia.com> --- arch/arm/mach-tegra/reset.c | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-)