Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
[linux-drm-fsl-dcu.git] / drivers / crypto / caam / ctrl.c
index bc6d820812b6a73e83c6596caa48ae7d475c315a..63fb1af2c43187fe398663869b5877fa16bf8834 100644 (file)
 #include "error.h"
 #include "ctrl.h"
 
-static int caam_remove(struct platform_device *pdev)
-{
-       struct device *ctrldev;
-       struct caam_drv_private *ctrlpriv;
-       struct caam_drv_private_jr *jrpriv;
-       struct caam_full __iomem *topregs;
-       int ring, ret = 0;
-
-       ctrldev = &pdev->dev;
-       ctrlpriv = dev_get_drvdata(ctrldev);
-       topregs = (struct caam_full __iomem *)ctrlpriv->ctrl;
-
-       /* shut down JobRs */
-       for (ring = 0; ring < ctrlpriv->total_jobrs; ring++) {
-               ret |= caam_jr_shutdown(ctrlpriv->jrdev[ring]);
-               jrpriv = dev_get_drvdata(ctrlpriv->jrdev[ring]);
-               irq_dispose_mapping(jrpriv->irq);
-       }
-
-       /* Shut down debug views */
-#ifdef CONFIG_DEBUG_FS
-       debugfs_remove_recursive(ctrlpriv->dfs_root);
-#endif
-
-       /* Unmap controller region */
-       iounmap(&topregs->ctrl);
-
-       kfree(ctrlpriv->jrdev);
-       kfree(ctrlpriv);
-
-       return ret;
-}
-
 /*
  * Descriptor to instantiate RNG State Handle 0 in normal mode and
  * load the JDKEK, TDKEK and TDSK registers
  */
-static void build_instantiation_desc(u32 *desc)
+static void build_instantiation_desc(u32 *desc, int handle, int do_sk)
 {
-       u32 *jump_cmd;
+       u32 *jump_cmd, op_flags;
 
        init_job_desc(desc, 0);
 
+       op_flags = OP_TYPE_CLASS1_ALG | OP_ALG_ALGSEL_RNG |
+                       (handle << OP_ALG_AAI_SHIFT) | OP_ALG_AS_INIT;
+
        /* INIT RNG in non-test mode */
-       append_operation(desc, OP_TYPE_CLASS1_ALG | OP_ALG_ALGSEL_RNG |
-                        OP_ALG_AS_INIT);
+       append_operation(desc, op_flags);
+
+       if (!handle && do_sk) {
+               /*
+                * For SH0, Secure Keys must be generated as well
+                */
+
+               /* wait for done */
+               jump_cmd = append_jump(desc, JUMP_CLASS_CLASS1);
+               set_jump_tgt_here(desc, jump_cmd);
+
+               /*
+                * load 1 to clear written reg:
+                * resets the done interrrupt and returns the RNG to idle.
+                */
+               append_load_imm_u32(desc, 1, LDST_SRCDST_WORD_CLRW);
+
+               /* Initialize State Handle  */
+               append_operation(desc, OP_TYPE_CLASS1_ALG | OP_ALG_ALGSEL_RNG |
+                                OP_ALG_AAI_RNG4_SK);
+       }
 
-       /* wait for done */
-       jump_cmd = append_jump(desc, JUMP_CLASS_CLASS1);
-       set_jump_tgt_here(desc, jump_cmd);
+       append_jump(desc, JUMP_CLASS_CLASS1 | JUMP_TYPE_HALT);
+}
 
-       /*
-        * load 1 to clear written reg:
-        * resets the done interrupt and returns the RNG to idle.
-        */
-       append_load_imm_u32(desc, 1, LDST_SRCDST_WORD_CLRW);
+/* Descriptor for deinstantiation of State Handle 0 of the RNG block. */
+static void build_deinstantiation_desc(u32 *desc, int handle)
+{
+       init_job_desc(desc, 0);
 
-       /* generate secure keys (non-test) */
+       /* Uninstantiate State Handle 0 */
        append_operation(desc, OP_TYPE_CLASS1_ALG | OP_ALG_ALGSEL_RNG |
-                        OP_ALG_RNG4_SK);
+                        (handle << OP_ALG_AAI_SHIFT) | OP_ALG_AS_INITFINAL);
+
+       append_jump(desc, JUMP_CLASS_CLASS1 | JUMP_TYPE_HALT);
 }
 
-static int instantiate_rng(struct device *ctrldev)
+/*
+ * run_descriptor_deco0 - runs a descriptor on DECO0, under direct control of
+ *                       the software (no JR/QI used).
+ * @ctrldev - pointer to device
+ * @status - descriptor status, after being run
+ *
+ * Return: - 0 if no error occurred
+ *        - -ENODEV if the DECO couldn't be acquired
+ *        - -EAGAIN if an error occurred while executing the descriptor
+ */
+static inline int run_descriptor_deco0(struct device *ctrldev, u32 *desc,
+                                       u32 *status)
 {
        struct caam_drv_private *ctrlpriv = dev_get_drvdata(ctrldev);
        struct caam_full __iomem *topregs;
        unsigned int timeout = 100000;
-       u32 *desc;
-       int i, ret = 0;
-
-       desc = kmalloc(CAAM_CMD_SZ * 6, GFP_KERNEL | GFP_DMA);
-       if (!desc) {
-               dev_err(ctrldev, "can't allocate RNG init descriptor memory\n");
-               return -ENOMEM;
-       }
-       build_instantiation_desc(desc);
+       u32 deco_dbg_reg, flags;
+       int i;
 
        /* Set the bit to request direct access to DECO0 */
        topregs = (struct caam_full __iomem *)ctrlpriv->ctrl;
@@ -103,36 +96,219 @@ static int instantiate_rng(struct device *ctrldev)
 
        if (!timeout) {
                dev_err(ctrldev, "failed to acquire DECO 0\n");
-               ret = -EIO;
-               goto out;
+               clrbits32(&topregs->ctrl.deco_rq, DECORR_RQD0ENABLE);
+               return -ENODEV;
        }
 
        for (i = 0; i < desc_len(desc); i++)
-               topregs->deco.descbuf[i] = *(desc + i);
+               wr_reg32(&topregs->deco.descbuf[i], *(desc + i));
+
+       flags = DECO_JQCR_WHL;
+       /*
+        * If the descriptor length is longer than 4 words, then the
+        * FOUR bit in JRCTRL register must be set.
+        */
+       if (desc_len(desc) >= 4)
+               flags |= DECO_JQCR_FOUR;
 
-       wr_reg32(&topregs->deco.jr_ctl_hi, DECO_JQCR_WHL | DECO_JQCR_FOUR);
+       /* Instruct the DECO to execute it */
+       wr_reg32(&topregs->deco.jr_ctl_hi, flags);
 
        timeout = 10000000;
-       while ((rd_reg32(&topregs->deco.desc_dbg) & DECO_DBG_VALID) &&
-                                                                --timeout)
+       do {
+               deco_dbg_reg = rd_reg32(&topregs->deco.desc_dbg);
+               /*
+                * If an error occured in the descriptor, then
+                * the DECO status field will be set to 0x0D
+                */
+               if ((deco_dbg_reg & DESC_DBG_DECO_STAT_MASK) ==
+                   DESC_DBG_DECO_STAT_HOST_ERR)
+                       break;
                cpu_relax();
+       } while ((deco_dbg_reg & DESC_DBG_DECO_STAT_VALID) && --timeout);
 
-       if (!timeout) {
-               dev_err(ctrldev, "failed to instantiate RNG\n");
-               ret = -EIO;
-       }
+       *status = rd_reg32(&topregs->deco.op_status_hi) &
+                 DECO_OP_STATUS_HI_ERR_MASK;
 
+       /* Mark the DECO as free */
        clrbits32(&topregs->ctrl.deco_rq, DECORR_RQD0ENABLE);
-out:
+
+       if (!timeout)
+               return -EAGAIN;
+
+       return 0;
+}
+
+/*
+ * instantiate_rng - builds and executes a descriptor on DECO0,
+ *                  which initializes the RNG block.
+ * @ctrldev - pointer to device
+ * @state_handle_mask - bitmask containing the instantiation status
+ *                     for the RNG4 state handles which exist in
+ *                     the RNG4 block: 1 if it's been instantiated
+ *                     by an external entry, 0 otherwise.
+ * @gen_sk  - generate data to be loaded into the JDKEK, TDKEK and TDSK;
+ *           Caution: this can be done only once; if the keys need to be
+ *           regenerated, a POR is required
+ *
+ * Return: - 0 if no error occurred
+ *        - -ENOMEM if there isn't enough memory to allocate the descriptor
+ *        - -ENODEV if DECO0 couldn't be acquired
+ *        - -EAGAIN if an error occurred when executing the descriptor
+ *           f.i. there was a RNG hardware error due to not "good enough"
+ *           entropy being aquired.
+ */
+static int instantiate_rng(struct device *ctrldev, int state_handle_mask,
+                          int gen_sk)
+{
+       struct caam_drv_private *ctrlpriv = dev_get_drvdata(ctrldev);
+       struct caam_full __iomem *topregs;
+       struct rng4tst __iomem *r4tst;
+       u32 *desc, status, rdsta_val;
+       int ret = 0, sh_idx;
+
+       topregs = (struct caam_full __iomem *)ctrlpriv->ctrl;
+       r4tst = &topregs->ctrl.r4tst[0];
+
+       desc = kmalloc(CAAM_CMD_SZ * 7, GFP_KERNEL);
+       if (!desc)
+               return -ENOMEM;
+
+       for (sh_idx = 0; sh_idx < RNG4_MAX_HANDLES; sh_idx++) {
+               /*
+                * If the corresponding bit is set, this state handle
+                * was initialized by somebody else, so it's left alone.
+                */
+               if ((1 << sh_idx) & state_handle_mask)
+                       continue;
+
+               /* Create the descriptor for instantiating RNG State Handle */
+               build_instantiation_desc(desc, sh_idx, gen_sk);
+
+               /* Try to run it through DECO0 */
+               ret = run_descriptor_deco0(ctrldev, desc, &status);
+
+               /*
+                * If ret is not 0, or descriptor status is not 0, then
+                * something went wrong. No need to try the next state
+                * handle (if available), bail out here.
+                * Also, if for some reason, the State Handle didn't get
+                * instantiated although the descriptor has finished
+                * without any error (HW optimizations for later
+                * CAAM eras), then try again.
+                */
+               rdsta_val =
+                       rd_reg32(&topregs->ctrl.r4tst[0].rdsta) & RDSTA_IFMASK;
+               if (status || !(rdsta_val & (1 << sh_idx)))
+                       ret = -EAGAIN;
+               if (ret)
+                       break;
+
+               dev_info(ctrldev, "Instantiated RNG4 SH%d\n", sh_idx);
+               /* Clear the contents before recreating the descriptor */
+               memset(desc, 0x00, CAAM_CMD_SZ * 7);
+       }
+
        kfree(desc);
+
        return ret;
 }
 
 /*
- * By default, the TRNG runs for 200 clocks per sample;
- * 1600 clocks per sample generates better entropy.
+ * deinstantiate_rng - builds and executes a descriptor on DECO0,
+ *                    which deinitializes the RNG block.
+ * @ctrldev - pointer to device
+ * @state_handle_mask - bitmask containing the instantiation status
+ *                     for the RNG4 state handles which exist in
+ *                     the RNG4 block: 1 if it's been instantiated
+ *
+ * Return: - 0 if no error occurred
+ *        - -ENOMEM if there isn't enough memory to allocate the descriptor
+ *        - -ENODEV if DECO0 couldn't be acquired
+ *        - -EAGAIN if an error occurred when executing the descriptor
  */
-static void kick_trng(struct platform_device *pdev)
+static int deinstantiate_rng(struct device *ctrldev, int state_handle_mask)
+{
+       u32 *desc, status;
+       int sh_idx, ret = 0;
+
+       desc = kmalloc(CAAM_CMD_SZ * 3, GFP_KERNEL);
+       if (!desc)
+               return -ENOMEM;
+
+       for (sh_idx = 0; sh_idx < RNG4_MAX_HANDLES; sh_idx++) {
+               /*
+                * If the corresponding bit is set, then it means the state
+                * handle was initialized by us, and thus it needs to be
+                * deintialized as well
+                */
+               if ((1 << sh_idx) & state_handle_mask) {
+                       /*
+                        * Create the descriptor for deinstantating this state
+                        * handle
+                        */
+                       build_deinstantiation_desc(desc, sh_idx);
+
+                       /* Try to run it through DECO0 */
+                       ret = run_descriptor_deco0(ctrldev, desc, &status);
+
+                       if (ret || status) {
+                               dev_err(ctrldev,
+                                       "Failed to deinstantiate RNG4 SH%d\n",
+                                       sh_idx);
+                               break;
+                       }
+                       dev_info(ctrldev, "Deinstantiated RNG4 SH%d\n", sh_idx);
+               }
+       }
+
+       kfree(desc);
+
+       return ret;
+}
+
+static int caam_remove(struct platform_device *pdev)
+{
+       struct device *ctrldev;
+       struct caam_drv_private *ctrlpriv;
+       struct caam_full __iomem *topregs;
+       int ring, ret = 0;
+
+       ctrldev = &pdev->dev;
+       ctrlpriv = dev_get_drvdata(ctrldev);
+       topregs = (struct caam_full __iomem *)ctrlpriv->ctrl;
+
+       /* Remove platform devices for JobRs */
+       for (ring = 0; ring < ctrlpriv->total_jobrs; ring++) {
+               if (ctrlpriv->jrpdev[ring])
+                       of_device_unregister(ctrlpriv->jrpdev[ring]);
+       }
+
+       /* De-initialize RNG state handles initialized by this driver. */
+       if (ctrlpriv->rng4_sh_init)
+               deinstantiate_rng(ctrldev, ctrlpriv->rng4_sh_init);
+
+       /* Shut down debug views */
+#ifdef CONFIG_DEBUG_FS
+       debugfs_remove_recursive(ctrlpriv->dfs_root);
+#endif
+
+       /* Unmap controller region */
+       iounmap(&topregs->ctrl);
+
+       kfree(ctrlpriv->jrpdev);
+       kfree(ctrlpriv);
+
+       return ret;
+}
+
+/*
+ * kick_trng - sets the various parameters for enabling the initialization
+ *            of the RNG4 block in CAAM
+ * @pdev - pointer to the platform device
+ * @ent_delay - Defines the length (in system clocks) of each entropy sample.
+ */
+static void kick_trng(struct platform_device *pdev, int ent_delay)
 {
        struct device *ctrldev = &pdev->dev;
        struct caam_drv_private *ctrlpriv = dev_get_drvdata(ctrldev);
@@ -145,14 +321,31 @@ static void kick_trng(struct platform_device *pdev)
 
        /* put RNG4 into program mode */
        setbits32(&r4tst->rtmctl, RTMCTL_PRGM);
-       /* 1600 clocks per sample */
+
+       /*
+        * Performance-wise, it does not make sense to
+        * set the delay to a value that is lower
+        * than the last one that worked (i.e. the state handles
+        * were instantiated properly. Thus, instead of wasting
+        * time trying to set the values controlling the sample
+        * frequency, the function simply returns.
+        */
+       val = (rd_reg32(&r4tst->rtsdctl) & RTSDCTL_ENT_DLY_MASK)
+             >> RTSDCTL_ENT_DLY_SHIFT;
+       if (ent_delay <= val) {
+               /* put RNG4 into run mode */
+               clrbits32(&r4tst->rtmctl, RTMCTL_PRGM);
+               return;
+       }
+
        val = rd_reg32(&r4tst->rtsdctl);
-       val = (val & ~RTSDCTL_ENT_DLY_MASK) | (1600 << RTSDCTL_ENT_DLY_SHIFT);
+       val = (val & ~RTSDCTL_ENT_DLY_MASK) |
+             (ent_delay << RTSDCTL_ENT_DLY_SHIFT);
        wr_reg32(&r4tst->rtsdctl, val);
-       /* min. freq. count */
-       wr_reg32(&r4tst->rtfrqmin, 400);
-       /* max. freq. count */
-       wr_reg32(&r4tst->rtfrqmax, 6400);
+       /* min. freq. count, equal to 1/4 of the entropy sample length */
+       wr_reg32(&r4tst->rtfrqmin, ent_delay >> 2);
+       /* max. freq. count, equal to 8 times the entropy sample length */
+       wr_reg32(&r4tst->rtfrqmax, ent_delay << 3);
        /* put RNG4 into run mode */
        clrbits32(&r4tst->rtmctl, RTMCTL_PRGM);
 }
@@ -193,7 +386,7 @@ EXPORT_SYMBOL(caam_get_era);
 /* Probe routine for CAAM top (controller) level */
 static int caam_probe(struct platform_device *pdev)
 {
-       int ret, ring, rspec;
+       int ret, ring, rspec, gen_sk, ent_delay = RTSDCTL_ENT_DLY_MIN;
        u64 caam_id;
        struct device *dev;
        struct device_node *nprop, *np;
@@ -258,8 +451,9 @@ static int caam_probe(struct platform_device *pdev)
                        rspec++;
        }
 
-       ctrlpriv->jrdev = kzalloc(sizeof(struct device *) * rspec, GFP_KERNEL);
-       if (ctrlpriv->jrdev == NULL) {
+       ctrlpriv->jrpdev = kzalloc(sizeof(struct platform_device *) * rspec,
+                                                               GFP_KERNEL);
+       if (ctrlpriv->jrpdev == NULL) {
                iounmap(&topregs->ctrl);
                return -ENOMEM;
        }
@@ -267,13 +461,24 @@ static int caam_probe(struct platform_device *pdev)
        ring = 0;
        ctrlpriv->total_jobrs = 0;
        for_each_compatible_node(np, NULL, "fsl,sec-v4.0-job-ring") {
-               caam_jr_probe(pdev, np, ring);
+               ctrlpriv->jrpdev[ring] =
+                               of_platform_device_create(np, NULL, dev);
+               if (!ctrlpriv->jrpdev[ring]) {
+                       pr_warn("JR%d Platform device creation error\n", ring);
+                       continue;
+               }
                ctrlpriv->total_jobrs++;
                ring++;
        }
        if (!ring) {
                for_each_compatible_node(np, NULL, "fsl,sec4.0-job-ring") {
-                       caam_jr_probe(pdev, np, ring);
+                       ctrlpriv->jrpdev[ring] =
+                               of_platform_device_create(np, NULL, dev);
+                       if (!ctrlpriv->jrpdev[ring]) {
+                               pr_warn("JR%d Platform device creation error\n",
+                                       ring);
+                               continue;
+                       }
                        ctrlpriv->total_jobrs++;
                        ring++;
                }
@@ -299,16 +504,55 @@ static int caam_probe(struct platform_device *pdev)
 
        /*
         * If SEC has RNG version >= 4 and RNG state handle has not been
-        * already instantiated ,do RNG instantiation
+        * already instantiateddo RNG instantiation
         */
-       if ((cha_vid & CHA_ID_RNG_MASK) >> CHA_ID_RNG_SHIFT >= 4 &&
-           !(rd_reg32(&topregs->ctrl.r4tst[0].rdsta) & RDSTA_IF0)) {
-               kick_trng(pdev);
-               ret = instantiate_rng(dev);
+       if ((cha_vid & CHA_ID_RNG_MASK) >> CHA_ID_RNG_SHIFT >= 4) {
+               ctrlpriv->rng4_sh_init =
+                       rd_reg32(&topregs->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_IFMASK;
+               do {
+                       int inst_handles =
+                               rd_reg32(&topregs->ctrl.r4tst[0].rdsta) &
+                                                               RDSTA_IFMASK;
+                       /*
+                        * 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)) {
+                               kick_trng(pdev, ent_delay);
+                               ent_delay += 400;
+                       }
+                       /*
+                        * if instantiate_rng(...) fails, the loop will rerun
+                        * and the kick_trng(...) function will modfiy the
+                        * upper and lower limits of the entropy sampling
+                        * interval, leading to a sucessful initialization of
+                        * the RNG.
+                        */
+                       ret = instantiate_rng(dev, inst_handles,
+                                             gen_sk);
+               } while ((ret == -EAGAIN) && (ent_delay < RTSDCTL_ENT_DLY_MAX));
                if (ret) {
+                       dev_err(dev, "failed to instantiate RNG");
                        caam_remove(pdev);
                        return ret;
                }
+               /*
+                * Set handles init'ed by this module as the complement of the
+                * already initialized ones
+                */
+               ctrlpriv->rng4_sh_init = ~ctrlpriv->rng4_sh_init & RDSTA_IFMASK;
 
                /* Enable RDB bit so that RNG works faster */
                setbits32(&topregs->ctrl.scfgr, SCFGR_RDBENABLE);