[crypto] Disable the iCache when entering CL #27678
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As code in CL should be executed in constant time, this commit adds new functions that allow the CL to disable and restore the state of the Ibex instruction cache. Signed-off-by: Pascal Nasahl <nasahlpa@lowrisc.org>
When entering the CL over the API, disable the iCache if it is enabled. When leaving the CL, restore the previous state of the iCache (enabled or disabled). Signed-off-by: Pascal Nasahl <nasahlpa@lowrisc.org>
johannheyszl
approved these changes
Jul 23, 2025
| @@ -27,6 +34,33 @@ static void wait_rnd_valid(void) { | |||
| } | |||
| } | |||
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| hardened_bool_t ibex_disable_icache(void) { | |||
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I think this makes sense. Requires the caller to create a var and handle the state in each function but avoids global var and state
nasahlpa
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timothytrippel,
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moidx,
cfrantz and
vogelpi
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added
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CherryPick:earlgrey_1.0.0
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This PR adds functionality to the CL that allows the library to disable and restore the instruction cache state.
To start discussions, this PR adds the iCache disable / restore to the AES-GCM CL implementation.