Messages in this thread | | | Date | Thu, 1 Jun 2023 17:00:11 +0530 | Subject | Re: [PATCH v3 01/10] nvmem: qfprom: Add support for secure reading | From | Komal Bajaj <> |
| |
On 5/28/2023 2:20 AM, Bjorn Andersson wrote: > On Fri, May 12, 2023 at 05:51:25PM +0530, Komal Bajaj wrote: >> For some of the Qualcomm SoC's, it is possible that >> some of the fuse regions or entire qfprom region is >> protected from non-secure access. In such situations, >> linux will have to use secure calls to read the region. >> With that motivation, add the support of reading secure >> regions in qfprom driver. Ensuring the address to read >> is word aligned since our secure I/O only supports word >> size I/O. >> >> Signed-off-by: Komal Bajaj <quic_kbajaj@quicinc.com> >> --- >> drivers/nvmem/Kconfig | 1 + >> drivers/nvmem/qfprom.c | 69 +++++++++++++++++++++++++++++++++--------- >> 2 files changed, 55 insertions(+), 15 deletions(-) >> >> diff --git a/drivers/nvmem/Kconfig b/drivers/nvmem/Kconfig >> index b291b27048c7..3d896ba29b89 100644 >> --- a/drivers/nvmem/Kconfig >> +++ b/drivers/nvmem/Kconfig >> @@ -209,6 +209,7 @@ config NVMEM_QCOM_QFPROM >> tristate "QCOM QFPROM Support" >> depends on ARCH_QCOM || COMPILE_TEST >> depends on HAS_IOMEM >> + select QCOM_SCM >> help >> Say y here to enable QFPROM support. The QFPROM provides access >> functions for QFPROM data to rest of the drivers via nvmem interface. >> diff --git a/drivers/nvmem/qfprom.c b/drivers/nvmem/qfprom.c >> index c1e893c8a247..20662e2d3732 100644 >> --- a/drivers/nvmem/qfprom.c >> +++ b/drivers/nvmem/qfprom.c >> @@ -16,6 +16,7 @@ >> #include <linux/pm_runtime.h> >> #include <linux/property.h> >> #include <linux/regulator/consumer.h> >> +#include <linux/firmware/qcom/qcom_scm.h> >> >> /* Blow timer clock frequency in Mhz */ >> #define QFPROM_BLOW_TIMER_OFFSET 0x03c >> @@ -59,21 +60,22 @@ struct qfprom_soc_data { >> /** >> * struct qfprom_priv - structure holding qfprom attributes >> * >> - * @qfpraw: iomapped memory space for qfprom-efuse raw address space. >> - * @qfpconf: iomapped memory space for qfprom-efuse configuration address >> - * space. >> + * @qfpraw: iomapped memory space for qfprom-efuse raw address space. >> + * @qfpconf: iomapped memory space for qfprom-efuse configuration address space. > Adjusting the indentation makes it unnecessarily hard to see what you > actually changed. Okay, will maintain the existing indentation. > >> * @qfpcorrected: iomapped memory space for qfprom corrected address space. >> - * @qfpsecurity: iomapped memory space for qfprom security control space. >> - * @dev: qfprom device structure. >> - * @secclk: Clock supply. >> - * @vcc: Regulator supply. >> - * @soc_data: Data that for things that varies from SoC to SoC. >> + * @qfpsecurity: iomapped memory space for qfprom security control space. >> + * @qfpseccorrected: starting physical address for qfprom secure corrected address space. >> + * @dev: qfprom device structure. >> + * @secclk: Clock supply. >> + * @vcc: Regulator supply. >> + * @soc_data: Data that for things that varies from SoC to SoC. >> */ >> struct qfprom_priv { >> void __iomem *qfpraw; >> void __iomem *qfpconf; >> void __iomem *qfpcorrected; >> void __iomem *qfpsecurity; >> + phys_addr_t qfpseccorrected; >> struct device *dev; >> struct clk *secclk; >> struct regulator *vcc; >> @@ -99,10 +101,12 @@ struct qfprom_touched_values { >> * >> * @keepout: Array of keepout regions for this SoC. >> * @nkeepout: Number of elements in the keepout array. >> + * @secure: Is qfprom region for this SoC protected from non-secure access. >> */ >> struct qfprom_soc_compatible_data { >> const struct nvmem_keepout *keepout; >> unsigned int nkeepout; >> + bool secure; >> }; >> >> static const struct nvmem_keepout sc7180_qfprom_keepout[] = { >> @@ -334,6 +338,34 @@ static int qfprom_reg_read(void *context, >> return 0; >> } >> >> +static int qfprom_sec_reg_read(void *context, unsigned int reg, void *_val, size_t bytes) >> +{ >> + struct qfprom_priv *priv = context; >> + u8 *val = _val; >> + int buf_start, buf_end, index, i = 0; >> + char *buffer; >> + u32 read_val; >> + >> + buf_start = ALIGN_DOWN(reg, 4); >> + buf_end = ALIGN(reg + bytes, 4); >> + buffer = kzalloc(buf_end - buf_start, GFP_KERNEL); >> + if (!buffer) >> + return -ENOMEM; > I don't you need all these variables, the full temp buffer or the two > memcpy... I think something like this should do the trick: > > unsigned int i; > u8 *val = _val; > u8 tmp[4]; > > for (i = 0; i < bytes; i++, reg++) > if (i == 0 || reg % 4 == 0) > qcom_scm_io_readl(qfpseccorrected + (reg & ~3), tmp); > > val[i] = tmp[reg & 3]; > } Thanks, for this. Will make the suggested change in the next patch series. >> + >> + for (index = buf_start; index < buf_end; index += 4, i += 4) { >> + if (qcom_scm_io_readl(priv->qfpseccorrected + index, &read_val)) { >> + dev_err(priv->dev, "Couldn't access feature register\n"); > What's a "feature register"? It's a fuse register that we are trying to read here.
Thanks Komal
> > Regards, > Bjorn > >> + kfree_sensitive(buffer); >> + return -EINVAL; >> + } >> + memcpy(buffer + i, &read_val, 4); >> + } >> + >> + memcpy(val, buffer + reg % 4, bytes); >> + kfree_sensitive(buffer); >> + return 0; >> +} >> + >> static void qfprom_runtime_disable(void *data) >> { >> pm_runtime_disable(data); >> @@ -373,13 +405,6 @@ static int qfprom_probe(struct platform_device *pdev) >> if (!priv) >> return -ENOMEM; >> >> - /* The corrected section is always provided */ >> - res = platform_get_resource(pdev, IORESOURCE_MEM, 0); >> - priv->qfpcorrected = devm_ioremap_resource(dev, res); >> - if (IS_ERR(priv->qfpcorrected)) >> - return PTR_ERR(priv->qfpcorrected); >> - >> - econfig.size = resource_size(res); >> econfig.dev = dev; >> econfig.priv = priv; >> >> @@ -390,6 +415,20 @@ static int qfprom_probe(struct platform_device *pdev) >> econfig.nkeepout = soc_data->nkeepout; >> } >> >> + /* The corrected section is always provided */ >> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); >> + >> + if (soc_data && soc_data->secure) { >> + priv->qfpseccorrected = res->start; >> + econfig.reg_read = qfprom_sec_reg_read; >> + } else { >> + priv->qfpcorrected = devm_ioremap_resource(dev, res); >> + if (IS_ERR(priv->qfpcorrected)) >> + return PTR_ERR(priv->qfpcorrected); >> + } >> + >> + econfig.size = resource_size(res); >> + >> /* >> * If more than one region is provided then the OS has the ability >> * to write. >> -- >> 2.17.1 >>
| |