86 lines
2.8 KiB
Diff
86 lines
2.8 KiB
Diff
From df2f34ef1d924125ffaf29dfdaf7cdbd3183c321 Mon Sep 17 00:00:00 2001
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From: Patrick Delaunay <patrick.delaunay@foss.st.com>
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Date: Mon, 6 Feb 2023 13:43:52 +0000
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Subject: [PATCH] nvmem: stm32: detect bsec pta presence for STM32MP15x
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On STM32MP15x SoC, the SMC backend is optional when OP-TEE is used;
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the PTA BSEC should be used as it is done on STM32MP13x platform,
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but the BSEC SMC can be also used: it is a legacy mode in OP-TEE,
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not recommended but used in previous OP-TEE firmware.
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The presence of OP-TEE is dynamically detected in STM32MP15x device tree
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and the supported NVMEM backend is dynamically detected:
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- PTA with stm32_bsec_pta_find
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- SMC with stm32_bsec_check
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With OP-TEE but without PTA and SMC detection, the probe is deferred for
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STM32MP15x devices.
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On STM32MP13x platform, only the PTA is supported with cfg->ta = true
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and this detection is skipped.
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Signed-off-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
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Reviewed-by: Etienne Carriere <etienne.carriere@linaro.org>
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Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
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Link: https://lore.kernel.org/r/20230206134356.839737-19-srinivas.kandagatla@linaro.org
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Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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---
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drivers/nvmem/stm32-romem.c | 38 +++++++++++++++++++++++++++++++++----
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1 file changed, 34 insertions(+), 4 deletions(-)
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--- a/drivers/nvmem/stm32-romem.c
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+++ b/drivers/nvmem/stm32-romem.c
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@@ -159,6 +159,31 @@ static int stm32_bsec_pta_write(void *co
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return stm32_bsec_optee_ta_write(priv->ctx, priv->lower, offset, buf, bytes);
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}
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+static bool stm32_bsec_smc_check(void)
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+{
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+ u32 val;
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+ int ret;
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+
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+ /* check that the OP-TEE support the BSEC SMC (legacy mode) */
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+ ret = stm32_bsec_smc(STM32_SMC_READ_SHADOW, 0, 0, &val);
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+
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+ return !ret;
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+}
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+
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+static bool optee_presence_check(void)
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+{
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+ struct device_node *np;
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+ bool tee_detected = false;
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+
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+ /* check that the OP-TEE node is present and available. */
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+ np = of_find_compatible_node(NULL, NULL, "linaro,optee-tz");
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+ if (np && of_device_is_available(np))
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+ tee_detected = true;
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+ of_node_put(np);
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+
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+ return tee_detected;
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+}
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+
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static int stm32_romem_probe(struct platform_device *pdev)
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{
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const struct stm32_romem_cfg *cfg;
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@@ -195,11 +220,16 @@ static int stm32_romem_probe(struct plat
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} else {
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priv->cfg.size = cfg->size;
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priv->lower = cfg->lower;
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- if (cfg->ta) {
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+ if (cfg->ta || optee_presence_check()) {
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rc = stm32_bsec_optee_ta_open(&priv->ctx);
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- /* wait for OP-TEE client driver to be up and ready */
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- if (rc)
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- return rc;
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+ if (rc) {
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+ /* wait for OP-TEE client driver to be up and ready */
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+ if (rc == -EPROBE_DEFER)
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+ return -EPROBE_DEFER;
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+ /* BSEC PTA is required or SMC not supported */
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+ if (cfg->ta || !stm32_bsec_smc_check())
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+ return rc;
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+ }
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}
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if (priv->ctx) {
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rc = devm_add_action_or_reset(dev, stm32_bsec_optee_ta_close, priv->ctx);
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