| Message ID | 20230405103306.1763491-1-meenakshi.aggarwal@nxp.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Delegated to: | Herbert Xu |
| Headers | show |
| Series | [v2] crypto: caam - refactor RNG initialization | expand |
HI > -----Original Message----- > From: Meenakshi Aggarwal <meenakshi.aggarwal@nxp.com> > Sent: Wednesday, April 5, 2023 4:03 PM > To: Horia Geanta <horia.geanta@nxp.com>; Varun Sethi <V.Sethi@nxp.com>; > Pankaj Gupta <pankaj.gupta@nxp.com>; Gaurav Jain <gaurav.jain@nxp.com>; > herbert@gondor.apana.org.au; davem@davemloft.net; linux- > crypto@vger.kernel.org; linux-kernel@vger.kernel.org; > leonard.crestez@nxp.com; Aisheng Dong <aisheng.dong@nxp.com> > Cc: Meenakshi Aggarwal <meenakshi.aggarwal@nxp.com> > Subject: [PATCH v2] crypto: caam - refactor RNG initialization > > From: Horia GeantA <horia.geanta@nxp.com> > > RNG (re-)initialization will be needed on pm resume path, thus refactor the > corresponding code out of the probe callback. > > Signed-off-by: Horia GeantA <horia.geanta@nxp.com> > Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com> > Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com> > Signed-off-by: Meenakshi Aggarwal <meenakshi.aggarwal@nxp.com> > --- > changes in v2: > Rebased on "page 0" patches > > NOTE: This patch depends on "page 0" patches, which are under review on > mailing list. > > drivers/crypto/caam/ctrl.c | 201 ++++++++++++++++++----------------- > drivers/crypto/caam/intern.h | 1 + > 2 files changed, 104 insertions(+), 98 deletions(-) > > diff --git a/drivers/crypto/caam/ctrl.c b/drivers/crypto/caam/ctrl.c index > 9c5a035e1b96..852d538cfc25 100644 > --- a/drivers/crypto/caam/ctrl.c > +++ b/drivers/crypto/caam/ctrl.c > @@ -342,13 +342,12 @@ static int instantiate_rng(struct device *ctrldev, int > state_handle_mask, > /* > * kick_trng - sets the various parameters for enabling the initialization > * of the RNG4 block in CAAM > - * @pdev - pointer to the platform device > + * @dev - pointer to the controller device > * @ent_delay - Defines the length (in system clocks) of each entropy sample. > */ > -static void kick_trng(struct platform_device *pdev, int ent_delay) > +static void kick_trng(struct device *dev, int ent_delay) > { > - struct device *ctrldev = &pdev->dev; > - struct caam_drv_private *ctrlpriv = dev_get_drvdata(ctrldev); > + struct caam_drv_private *ctrlpriv = dev_get_drvdata(dev); > struct caam_ctrl __iomem *ctrl; > struct rng4tst __iomem *r4tst; > u32 val; > @@ -589,6 +588,100 @@ static void caam_remove_debugfs(void *root) > debugfs_remove_recursive(root); > } > > +static int caam_ctrl_rng_init(struct device *dev) { > + struct caam_drv_private *ctrlpriv = dev_get_drvdata(dev); > + struct caam_ctrl __iomem *ctrl = ctrlpriv->ctrl; > + int ret, gen_sk, ent_delay = RTSDCTL_ENT_DLY_MIN; > + u8 rng_vid; > + > + if (ctrlpriv->era < 10) { > + struct caam_perfmon __iomem *perfmon; > + > + perfmon = ctrlpriv->total_jobrs ? > + (struct caam_perfmon *)&ctrlpriv->jr[0]->perfmon : > + (struct caam_perfmon *)&ctrl->perfmon; > + > + rng_vid = (rd_reg32(&perfmon->cha_id_ls) & > + CHA_ID_LS_RNG_MASK) >> CHA_ID_LS_RNG_SHIFT; > + } else { > + struct version_regs __iomem *vreg; > + > + vreg = ctrlpriv->total_jobrs ? > + (struct version_regs __iomem *)&ctrlpriv->jr[0]->vreg : > + (struct version_regs __iomem *)&ctrl->vreg; > + > + rng_vid = (rd_reg32(&vreg->rng) & CHA_VER_VID_MASK) >> > + CHA_VER_VID_SHIFT; > + } > + > + /* > + * If SEC has RNG version >= 4 and RNG state handle has not been > + * already instantiated, do RNG instantiation > + * In case of SoCs with Management Complex, RNG is managed by MC > f/w. > + */ > + if (!(ctrlpriv->mc_en && ctrlpriv->pr_support) && rng_vid >= 4) { > + ctrlpriv->rng4_sh_init = > + rd_reg32(&ctrl->r4tst[0].rdsta); > + /* > + * If the secure keys (TDKEK, JDKEK, TDSK), were already > + * generated, signal this to the function that is instantiating > + * the state handles. An error would occur if RNG4 attempts > + * to regenerate these keys before the next POR. > + */ > + gen_sk = ctrlpriv->rng4_sh_init & RDSTA_SKVN ? 0 : 1; > + ctrlpriv->rng4_sh_init &= RDSTA_MASK; > + do { > + int inst_handles = > + rd_reg32(&ctrl->r4tst[0].rdsta) & RDSTA_MASK; > + /* > + * If either SH were instantiated by somebody else > + * (e.g. u-boot) then it is assumed that the entropy > + * parameters are properly set and thus the function > + * setting these (kick_trng(...)) is skipped. > + * Also, if a handle was instantiated, do not change > + * the TRNG parameters. > + */ > + if (!(ctrlpriv->rng4_sh_init || inst_handles)) { > + dev_info(dev, > + "Entropy delay = %u\n", > + ent_delay); > + kick_trng(dev, ent_delay); > + ent_delay += 400; > + } > + /* > + * if instantiate_rng(...) fails, the loop will rerun > + * and the kick_trng(...) function will modify the > + * upper and lower limits of the entropy sampling > + * interval, leading to a successful initialization of > + * the RNG. > + */ > + ret = instantiate_rng(dev, inst_handles, > + gen_sk); > + if (ret == -EAGAIN) > + /* > + * if here, the loop will rerun, > + * so don't hog the CPU > + */ > + cpu_relax(); > + } while ((ret == -EAGAIN) && (ent_delay < > RTSDCTL_ENT_DLY_MAX)); > + if (ret) { > + dev_err(dev, "failed to instantiate RNG"); > + return ret; > + } > + /* > + * Set handles initialized by this module as the complement of > + * the already initialized ones > + */ > + ctrlpriv->rng4_sh_init = ~ctrlpriv->rng4_sh_init & RDSTA_MASK; > + > + /* Enable RDB bit so that RNG works faster */ > + clrsetbits_32(&ctrl->scfgr, 0, SCFGR_RDBENABLE); > + } > + > + return 0; > +} > + > #ifdef CONFIG_FSL_MC_BUS > static bool check_version(struct fsl_mc_version *mc_version, u32 major, > u32 minor, u32 revision) > @@ -609,17 +702,10 @@ static bool check_version(struct fsl_mc_version > *mc_version, u32 major, } #endif > > -static bool needs_entropy_delay_adjustment(void) > -{ > - if (of_machine_is_compatible("fsl,imx6sx")) > - return true; > - return false; > -} This will break the RNG on i.MX6SX platform. Please rework this. Regards Gaurav Jain > - > /* Probe routine for CAAM top (controller) level */ static int caam_probe(struct > platform_device *pdev) { > - int ret, ring, gen_sk, ent_delay = RTSDCTL_ENT_DLY_MIN; > + int ret, ring; > u64 caam_id; > const struct soc_device_attribute *imx_soc_match; > struct device *dev; > @@ -629,10 +715,8 @@ static int caam_probe(struct platform_device *pdev) > struct caam_perfmon __iomem *perfmon; > struct dentry *dfs_root; > u32 scfgr, comp_params; > - u8 rng_vid; > int pg_size; > int BLOCK_OFFSET = 0; > - bool pr_support = false; > bool reg_access = true; > > ctrlpriv = devm_kzalloc(&pdev->dev, sizeof(*ctrlpriv), GFP_KERNEL); > @@ -768,7 +852,8 @@ static int caam_probe(struct platform_device *pdev) > > mc_version = fsl_mc_get_version(); > if (mc_version) > - pr_support = check_version(mc_version, 10, 20, 0); > + ctrlpriv->pr_support = check_version(mc_version, 10, > 20, > + 0); > else > return -EPROBE_DEFER; > } > @@ -859,9 +944,6 @@ static int caam_probe(struct platform_device *pdev) > return -ENOMEM; > } > > - if (!reg_access) > - goto report_live; > - > comp_params = rd_reg32(&perfmon->comp_parms_ls); > ctrlpriv->blob_present = !!(comp_params & CTPR_LS_BLOB); > > @@ -871,8 +953,6 @@ static int caam_probe(struct platform_device *pdev) > * check both here. > */ > if (ctrlpriv->era < 10) { > - rng_vid = (rd_reg32(&perfmon->cha_id_ls) & > - CHA_ID_LS_RNG_MASK) >> CHA_ID_LS_RNG_SHIFT; > ctrlpriv->blob_present = ctrlpriv->blob_present && > (rd_reg32(&perfmon->cha_num_ls) & > CHA_ID_LS_AES_MASK); > } else { > @@ -882,91 +962,16 @@ static int caam_probe(struct platform_device *pdev) > (struct version_regs __iomem *)&ctrlpriv->jr[0]->vreg : > (struct version_regs __iomem *)&ctrl->vreg; > > - rng_vid = (rd_reg32(&vreg->rng) & CHA_VER_VID_MASK) >> > - CHA_VER_VID_SHIFT; > ctrlpriv->blob_present = ctrlpriv->blob_present && > (rd_reg32(&vreg->aesa) & > CHA_VER_MISC_AES_NUM_MASK); > } > > - /* > - * If SEC has RNG version >= 4 and RNG state handle has not been > - * already instantiated, do RNG instantiation > - * In case of SoCs with Management Complex, RNG is managed by MC > f/w. > - */ > - if (!(ctrlpriv->mc_en && pr_support) && rng_vid >= 4) { > - ctrlpriv->rng4_sh_init = > - rd_reg32(&ctrl->r4tst[0].rdsta); > - /* > - * If the secure keys (TDKEK, JDKEK, TDSK), were already > - * generated, signal this to the function that is instantiating > - * the state handles. An error would occur if RNG4 attempts > - * to regenerate these keys before the next POR. > - */ > - gen_sk = ctrlpriv->rng4_sh_init & RDSTA_SKVN ? 0 : 1; > - ctrlpriv->rng4_sh_init &= RDSTA_MASK; > - do { > - int inst_handles = > - rd_reg32(&ctrl->r4tst[0].rdsta) & > - RDSTA_MASK; > - /* > - * If either SH were instantiated by somebody else > - * (e.g. u-boot) then it is assumed that the entropy > - * parameters are properly set and thus the function > - * setting these (kick_trng(...)) is skipped. > - * Also, if a handle was instantiated, do not change > - * the TRNG parameters. > - */ > - if (needs_entropy_delay_adjustment()) > - ent_delay = 12000; > - if (!(ctrlpriv->rng4_sh_init || inst_handles)) { > - dev_info(dev, > - "Entropy delay = %u\n", > - ent_delay); > - kick_trng(pdev, ent_delay); > - ent_delay += 400; > - } > - /* > - * if instantiate_rng(...) fails, the loop will rerun > - * and the kick_trng(...) function will modify the > - * upper and lower limits of the entropy sampling > - * interval, leading to a successful initialization of > - * the RNG. > - */ > - ret = instantiate_rng(dev, inst_handles, > - gen_sk); > - /* > - * Entropy delay is determined via TRNG > characterization. > - * TRNG characterization is run across different > voltages > - * and temperatures. > - * If worst case value for ent_dly is identified, > - * the loop can be skipped for that platform. > - */ > - if (needs_entropy_delay_adjustment()) > - break; > - if (ret == -EAGAIN) > - /* > - * if here, the loop will rerun, > - * so don't hog the CPU > - */ > - cpu_relax(); > - } while ((ret == -EAGAIN) && (ent_delay < > RTSDCTL_ENT_DLY_MAX)); > - if (ret) { > - dev_err(dev, "failed to instantiate RNG"); > + if (reg_access) { > + ret = caam_ctrl_rng_init(dev); > + if (ret) > return ret; > - } > - /* > - * Set handles initialized by this module as the complement of > - * the already initialized ones > - */ > - ctrlpriv->rng4_sh_init = ~ctrlpriv->rng4_sh_init & RDSTA_MASK; > - > - /* Enable RDB bit so that RNG works faster */ > - clrsetbits_32(&ctrl->scfgr, 0, SCFGR_RDBENABLE); > } > > -report_live: > - /* NOTE: RTIC detection ought to go here, around Si time */ > - > caam_id = (u64)rd_reg32(&perfmon->caam_id_ms) << 32 | > (u64)rd_reg32(&perfmon->caam_id_ls); > > diff --git a/drivers/crypto/caam/intern.h b/drivers/crypto/caam/intern.h index > 86ed1b91c22d..b4f7bf77f487 100644 > --- a/drivers/crypto/caam/intern.h > +++ b/drivers/crypto/caam/intern.h > @@ -95,6 +95,7 @@ struct caam_drv_private { > u8 blob_present; /* Nonzero if BLOB support present in device */ > u8 mc_en; /* Nonzero if MC f/w is active */ > u8 optee_en; /* Nonzero if OP-TEE f/w is active */ > + bool pr_support; /* RNG prediction resistance available */ > int secvio_irq; /* Security violation interrupt number */ > int virt_en; /* Virtualization enabled in CAAM */ > int era; /* CAAM Era (internal HW revision) */ > -- > 2.25.1
diff --git a/drivers/crypto/caam/ctrl.c b/drivers/crypto/caam/ctrl.c index 9c5a035e1b96..852d538cfc25 100644 --- a/drivers/crypto/caam/ctrl.c +++ b/drivers/crypto/caam/ctrl.c @@ -342,13 +342,12 @@ static int instantiate_rng(struct device *ctrldev, int state_handle_mask, /* * kick_trng - sets the various parameters for enabling the initialization * of the RNG4 block in CAAM - * @pdev - pointer to the platform device + * @dev - pointer to the controller device * @ent_delay - Defines the length (in system clocks) of each entropy sample. */ -static void kick_trng(struct platform_device *pdev, int ent_delay) +static void kick_trng(struct device *dev, int ent_delay) { - struct device *ctrldev = &pdev->dev; - struct caam_drv_private *ctrlpriv = dev_get_drvdata(ctrldev); + struct caam_drv_private *ctrlpriv = dev_get_drvdata(dev); struct caam_ctrl __iomem *ctrl; struct rng4tst __iomem *r4tst; u32 val; @@ -589,6 +588,100 @@ static void caam_remove_debugfs(void *root) debugfs_remove_recursive(root); } +static int caam_ctrl_rng_init(struct device *dev) +{ + struct caam_drv_private *ctrlpriv = dev_get_drvdata(dev); + struct caam_ctrl __iomem *ctrl = ctrlpriv->ctrl; + int ret, gen_sk, ent_delay = RTSDCTL_ENT_DLY_MIN; + u8 rng_vid; + + if (ctrlpriv->era < 10) { + struct caam_perfmon __iomem *perfmon; + + perfmon = ctrlpriv->total_jobrs ? + (struct caam_perfmon *)&ctrlpriv->jr[0]->perfmon : + (struct caam_perfmon *)&ctrl->perfmon; + + rng_vid = (rd_reg32(&perfmon->cha_id_ls) & + CHA_ID_LS_RNG_MASK) >> CHA_ID_LS_RNG_SHIFT; + } else { + struct version_regs __iomem *vreg; + + vreg = ctrlpriv->total_jobrs ? + (struct version_regs __iomem *)&ctrlpriv->jr[0]->vreg : + (struct version_regs __iomem *)&ctrl->vreg; + + rng_vid = (rd_reg32(&vreg->rng) & CHA_VER_VID_MASK) >> + CHA_VER_VID_SHIFT; + } + + /* + * If SEC has RNG version >= 4 and RNG state handle has not been + * already instantiated, do RNG instantiation + * In case of SoCs with Management Complex, RNG is managed by MC f/w. + */ + if (!(ctrlpriv->mc_en && ctrlpriv->pr_support) && rng_vid >= 4) { + ctrlpriv->rng4_sh_init = + rd_reg32(&ctrl->r4tst[0].rdsta); + /* + * If the secure keys (TDKEK, JDKEK, TDSK), were already + * generated, signal this to the function that is instantiating + * the state handles. An error would occur if RNG4 attempts + * to regenerate these keys before the next POR. + */ + gen_sk = ctrlpriv->rng4_sh_init & RDSTA_SKVN ? 0 : 1; + ctrlpriv->rng4_sh_init &= RDSTA_MASK; + do { + int inst_handles = + rd_reg32(&ctrl->r4tst[0].rdsta) & RDSTA_MASK; + /* + * If either SH were instantiated by somebody else + * (e.g. u-boot) then it is assumed that the entropy + * parameters are properly set and thus the function + * setting these (kick_trng(...)) is skipped. + * Also, if a handle was instantiated, do not change + * the TRNG parameters. + */ + if (!(ctrlpriv->rng4_sh_init || inst_handles)) { + dev_info(dev, + "Entropy delay = %u\n", + ent_delay); + kick_trng(dev, ent_delay); + ent_delay += 400; + } + /* + * if instantiate_rng(...) fails, the loop will rerun + * and the kick_trng(...) function will modify the + * upper and lower limits of the entropy sampling + * interval, leading to a successful initialization of + * the RNG. + */ + ret = instantiate_rng(dev, inst_handles, + gen_sk); + if (ret == -EAGAIN) + /* + * if here, the loop will rerun, + * so don't hog the CPU + */ + cpu_relax(); + } while ((ret == -EAGAIN) && (ent_delay < RTSDCTL_ENT_DLY_MAX)); + if (ret) { + dev_err(dev, "failed to instantiate RNG"); + return ret; + } + /* + * Set handles initialized by this module as the complement of + * the already initialized ones + */ + ctrlpriv->rng4_sh_init = ~ctrlpriv->rng4_sh_init & RDSTA_MASK; + + /* Enable RDB bit so that RNG works faster */ + clrsetbits_32(&ctrl->scfgr, 0, SCFGR_RDBENABLE); + } + + return 0; +} + #ifdef CONFIG_FSL_MC_BUS static bool check_version(struct fsl_mc_version *mc_version, u32 major, u32 minor, u32 revision) @@ -609,17 +702,10 @@ static bool check_version(struct fsl_mc_version *mc_version, u32 major, } #endif -static bool needs_entropy_delay_adjustment(void) -{ - if (of_machine_is_compatible("fsl,imx6sx")) - return true; - return false; -} - /* Probe routine for CAAM top (controller) level */ static int caam_probe(struct platform_device *pdev) { - int ret, ring, gen_sk, ent_delay = RTSDCTL_ENT_DLY_MIN; + int ret, ring; u64 caam_id; const struct soc_device_attribute *imx_soc_match; struct device *dev; @@ -629,10 +715,8 @@ static int caam_probe(struct platform_device *pdev) struct caam_perfmon __iomem *perfmon; struct dentry *dfs_root; u32 scfgr, comp_params; - u8 rng_vid; int pg_size; int BLOCK_OFFSET = 0; - bool pr_support = false; bool reg_access = true; ctrlpriv = devm_kzalloc(&pdev->dev, sizeof(*ctrlpriv), GFP_KERNEL); @@ -768,7 +852,8 @@ static int caam_probe(struct platform_device *pdev) mc_version = fsl_mc_get_version(); if (mc_version) - pr_support = check_version(mc_version, 10, 20, 0); + ctrlpriv->pr_support = check_version(mc_version, 10, 20, + 0); else return -EPROBE_DEFER; } @@ -859,9 +944,6 @@ static int caam_probe(struct platform_device *pdev) return -ENOMEM; } - if (!reg_access) - goto report_live; - comp_params = rd_reg32(&perfmon->comp_parms_ls); ctrlpriv->blob_present = !!(comp_params & CTPR_LS_BLOB); @@ -871,8 +953,6 @@ static int caam_probe(struct platform_device *pdev) * check both here. */ if (ctrlpriv->era < 10) { - rng_vid = (rd_reg32(&perfmon->cha_id_ls) & - CHA_ID_LS_RNG_MASK) >> CHA_ID_LS_RNG_SHIFT; ctrlpriv->blob_present = ctrlpriv->blob_present && (rd_reg32(&perfmon->cha_num_ls) & CHA_ID_LS_AES_MASK); } else { @@ -882,91 +962,16 @@ static int caam_probe(struct platform_device *pdev) (struct version_regs __iomem *)&ctrlpriv->jr[0]->vreg : (struct version_regs __iomem *)&ctrl->vreg; - rng_vid = (rd_reg32(&vreg->rng) & CHA_VER_VID_MASK) >> - CHA_VER_VID_SHIFT; ctrlpriv->blob_present = ctrlpriv->blob_present && (rd_reg32(&vreg->aesa) & CHA_VER_MISC_AES_NUM_MASK); } - /* - * If SEC has RNG version >= 4 and RNG state handle has not been - * already instantiated, do RNG instantiation - * In case of SoCs with Management Complex, RNG is managed by MC f/w. - */ - if (!(ctrlpriv->mc_en && pr_support) && rng_vid >= 4) { - ctrlpriv->rng4_sh_init = - rd_reg32(&ctrl->r4tst[0].rdsta); - /* - * If the secure keys (TDKEK, JDKEK, TDSK), were already - * generated, signal this to the function that is instantiating - * the state handles. An error would occur if RNG4 attempts - * to regenerate these keys before the next POR. - */ - gen_sk = ctrlpriv->rng4_sh_init & RDSTA_SKVN ? 0 : 1; - ctrlpriv->rng4_sh_init &= RDSTA_MASK; - do { - int inst_handles = - rd_reg32(&ctrl->r4tst[0].rdsta) & - RDSTA_MASK; - /* - * If either SH were instantiated by somebody else - * (e.g. u-boot) then it is assumed that the entropy - * parameters are properly set and thus the function - * setting these (kick_trng(...)) is skipped. - * Also, if a handle was instantiated, do not change - * the TRNG parameters. - */ - if (needs_entropy_delay_adjustment()) - ent_delay = 12000; - if (!(ctrlpriv->rng4_sh_init || inst_handles)) { - dev_info(dev, - "Entropy delay = %u\n", - ent_delay); - kick_trng(pdev, ent_delay); - ent_delay += 400; - } - /* - * if instantiate_rng(...) fails, the loop will rerun - * and the kick_trng(...) function will modify the - * upper and lower limits of the entropy sampling - * interval, leading to a successful initialization of - * the RNG. - */ - ret = instantiate_rng(dev, inst_handles, - gen_sk); - /* - * Entropy delay is determined via TRNG characterization. - * TRNG characterization is run across different voltages - * and temperatures. - * If worst case value for ent_dly is identified, - * the loop can be skipped for that platform. - */ - if (needs_entropy_delay_adjustment()) - break; - if (ret == -EAGAIN) - /* - * if here, the loop will rerun, - * so don't hog the CPU - */ - cpu_relax(); - } while ((ret == -EAGAIN) && (ent_delay < RTSDCTL_ENT_DLY_MAX)); - if (ret) { - dev_err(dev, "failed to instantiate RNG"); + if (reg_access) { + ret = caam_ctrl_rng_init(dev); + if (ret) return ret; - } - /* - * Set handles initialized by this module as the complement of - * the already initialized ones - */ - ctrlpriv->rng4_sh_init = ~ctrlpriv->rng4_sh_init & RDSTA_MASK; - - /* Enable RDB bit so that RNG works faster */ - clrsetbits_32(&ctrl->scfgr, 0, SCFGR_RDBENABLE); } -report_live: - /* NOTE: RTIC detection ought to go here, around Si time */ - caam_id = (u64)rd_reg32(&perfmon->caam_id_ms) << 32 | (u64)rd_reg32(&perfmon->caam_id_ls); diff --git a/drivers/crypto/caam/intern.h b/drivers/crypto/caam/intern.h index 86ed1b91c22d..b4f7bf77f487 100644 --- a/drivers/crypto/caam/intern.h +++ b/drivers/crypto/caam/intern.h @@ -95,6 +95,7 @@ struct caam_drv_private { u8 blob_present; /* Nonzero if BLOB support present in device */ u8 mc_en; /* Nonzero if MC f/w is active */ u8 optee_en; /* Nonzero if OP-TEE f/w is active */ + bool pr_support; /* RNG prediction resistance available */ int secvio_irq; /* Security violation interrupt number */ int virt_en; /* Virtualization enabled in CAAM */ int era; /* CAAM Era (internal HW revision) */