| Message ID | 20210225041129.58576-1-manivannan.sadhasivam@linaro.org |
|---|---|
| Headers | show |
| Series | Add support for secure regions in Qcom NANDc driver | expand |
Hi Manivannan, Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> wrote on Thu, 25 Feb 2021 09:41:29 +0530: > On a typical end product, a vendor may choose to secure some regions in > the NAND memory which are supposed to stay intact between FW upgrades. > The access to those regions will be blocked by a secure element like > Trustzone. So the normal world software like Linux kernel should not > touch these regions (including reading). > > The regions are declared using a NAND chip DT property, > "nand-secure-regions". So let's make use of this property and skip > access to the secure regions present in a system. > > Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> > --- [...] > config_nand_page_write(nandc); > @@ -2830,7 +2865,8 @@ static int qcom_nand_host_init_and_register(struct qcom_nand_controller *nandc, > struct nand_chip *chip = &host->chip; > struct mtd_info *mtd = nand_to_mtd(chip); > struct device *dev = nandc->dev; > - int ret; > + struct property *prop; > + int ret, length, nr_elem; > > ret = of_property_read_u32(dn, "reg", &host->cs); > if (ret) { > @@ -2886,6 +2922,24 @@ static int qcom_nand_host_init_and_register(struct qcom_nand_controller *nandc, > } > } > > + /* > + * Look for secure regions in the NAND chip. These regions are supposed > + * to be protected by a secure element like Trustzone. So the read/write > + * accesses to these regions will be blocked in the runtime by this > + * driver. > + */ > + prop = of_find_property(dn, "nand-secure-regions", &length); I'm not sure the nand- prefix on this property is needed here, but whatever. > + if (prop) { > + nr_elem = length / sizeof(u32); > + host->nr_sec_regions = nr_elem / 2; > + > + host->sec_regions = devm_kcalloc(dev, nr_elem, sizeof(u32), GFP_KERNEL); > + if (!host->sec_regions) > + return -ENOMEM; > + > + of_property_read_u32_array(dn, "nand-secure-regions", host->sec_regions, nr_elem); > + } > + I would move this before nand_scan(). If you don't, you should bail out with a nand_cleanup() upon error. > ret = mtd_device_parse_register(mtd, probes, NULL, NULL, 0); > if (ret) > nand_cleanup(chip); Otherwise lgtm. Thanks, Miquèl
On a typical end product, a vendor may choose to secure some regions in the NAND memory which are supposed to stay intact between FW upgrades. The access to those regions will be blocked by a secure element like Trustzone. So the normal world software like Linux kernel should not touch these regions (including reading). So this series adds a property for declaring such secure regions in DT so that the driver can skip touching them. While at it, the Qcom NANDc DT binding is also converted to YAML format. Thanks, Mani Changes in v2: * Moved the secure-regions property to generic NAND binding as a NAND chip property and renamed it as "nand-secure-regions". Manivannan Sadhasivam (3): dt-bindings: mtd: Convert Qcom NANDc binding to YAML dt-bindings: mtd: Add a property to declare secure regions in NAND chips mtd: rawnand: qcom: Add support for secure regions in NAND memory .../bindings/mtd/nand-controller.yaml | 7 + .../devicetree/bindings/mtd/qcom,nandc.yaml | 196 ++++++++++++++++++ .../devicetree/bindings/mtd/qcom_nandc.txt | 142 ------------- drivers/mtd/nand/raw/qcom_nandc.c | 72 ++++++- 4 files changed, 266 insertions(+), 151 deletions(-) create mode 100644 Documentation/devicetree/bindings/mtd/qcom,nandc.yaml delete mode 100644 Documentation/devicetree/bindings/mtd/qcom_nandc.txt -- 2.25.1