[PATCH 5.17 0836/1126] crypto: octeontx2 - CN10K CPT to RNM workaround

Greg Kroah-Hartman
2022-04-05T10:08:06Z

From: Srujana Challa <schalla@marvell.com>

[ Upstream commit bd9305b0cb69bfe98885a63a9e6231ae92e822e2 ]

When software sets CPT_AF_CTL[RNM_REQ_EN]=1 and RNM in not producing
entropy(i.e., RNM_ENTROPY_STATUS[NORMAL_CNT] < 0x40), the first cycle of
the response may be lost due to a conditional clocking issue. Due to
this, the subsequent random number stream will be corrupted. So, this
patch adds support to ensure RNM_ENTROPY_STATUS[NORMAL_CNT] = 0x40
before writing CPT_AF_CTL[RNM_REQ_EN] = 1, as a workaround.

Signed-off-by: Srujana Challa <schalla@marvell.com>
Signed-off-by: Shijith Thotton <sthotton@marvell.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
.../marvell/octeontx2/otx2_cptpf_ucode.c | 43 ++++++++++++++++++-
1 file changed, 42 insertions(+), 1 deletion(-)

diff --git a/drivers/crypto/marvell/octeontx2/otx2_cptpf_ucode.c b/drivers/crypto/marvell/octeontx2/otx2_cptpf_ucode.c
index 1b4d425bbf0e..7fd4503d9cfc 100644
--- a/drivers/crypto/marvell/octeontx2/otx2_cptpf_ucode.c
+++ b/drivers/crypto/marvell/octeontx2/otx2_cptpf_ucode.c
@@ -1076,6 +1076,39 @@ static void delete_engine_grps(struct pci_dev *pdev,
delete_engine_group(&pdev->dev, &eng_grps->grp[i]);
}

+#define PCI_DEVID_CN10K_RNM 0xA098
+#define RNM_ENTROPY_STATUS 0x8
+
+static void rnm_to_cpt_errata_fixup(struct device *dev)
+{
+ struct pci_dev *pdev;
+ void __iomem *base;
+ int timeout = 5000;
+
+ pdev = pci_get_device(PCI_VENDOR_ID_CAVIUM, PCI_DEVID_CN10K_RNM, NULL);
+ if (!pdev)
+ return;
+
+ base = pci_ioremap_bar(pdev, 0);
+ if (!base)
+ goto put_pdev;
+
+ while ((readq(base + RNM_ENTROPY_STATUS) & 0x7F) != 0x40) {
+ cpu_relax();
+ udelay(1);
+ timeout--;
+ if (!timeout) {
+ dev_warn(dev, "RNM is not producing entropy\n");
+ break;
+ }
+ }
+
+ iounmap(base);
+
+put_pdev:
+ pci_dev_put(pdev);
+}
+
int otx2_cpt_get_eng_grp(struct otx2_cpt_eng_grps *eng_grps, int eng_type)
{

@@ -1189,9 +1222,17 @@ int otx2_cpt_create_eng_grps(struct otx2_cptpf_dev *cptpf,

if (is_dev_otx2(pdev))
goto unlock;
+
+ /*
+ * Ensure RNM_ENTROPY_STATUS[NORMAL_CNT] = 0x40 before writing
+ * CPT_AF_CTL[RNM_REQ_EN] = 1 as a workaround for HW errata.
+ */
+ rnm_to_cpt_errata_fixup(&pdev->dev);
+
/*
* Configure engine group mask to allow context prefetching
- * for the groups.
+ * for the groups and enable random number request, to enable
+ * CPT to request random numbers from RNM.
*/
otx2_cpt_write_af_reg(&cptpf->afpf_mbox, pdev, CPT_AF_CTL,
OTX2_CPT_ALL_ENG_GRPS_MASK << 3 | BIT_ULL(16),
--
2.34.1