Hi Manivannan, Manivannan Sadhasivam <[email protected]> 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 <[email protected]> > --- [...] > 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
