| Message ID | 20170527063308.10483-1-bjorn.andersson@linaro.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [v2,1/3] firmware: qcom: scm: Expose secure IO service | expand |
On 05/26, Bjorn Andersson wrote: > In order to aid post-mortem debugging the Qualcomm platforms provides a > "memory download mode", where the boot loader will provide an interface > for custom tools to "download" the content of RAM to a host machine. > > The mode is triggered by writing a magic value somehwere in RAM, that is > read in the boot code path after a warm-restart. Two mechanism for > setting this magic value are supported in modern platforms; a direct SCM > call to enable the mode or through a secure io write of a magic value. > > In order for a normal reboot not to trigger "download mode" the magic > must be cleared during a clean reboot. > > Download mode has to be enabled by including qcom_scm.download_mode=1 on > the command line. Why the kernel command line parameter? If we keep the kernel command line param, perhaps we can also gain a config option to make it default enabled or default disabled so that we don't have to specify it on the commandline to get the feature all the time. > > diff --git a/Documentation/devicetree/bindings/firmware/qcom,scm.txt b/Documentation/devicetree/bindings/firmware/qcom,scm.txt > index 20f26fbce875..388817d1d00e 100644 > --- a/Documentation/devicetree/bindings/firmware/qcom,scm.txt > +++ b/Documentation/devicetree/bindings/firmware/qcom,scm.txt > @@ -18,6 +18,8 @@ Required properties: > * Core, iface, and bus clocks required for "qcom,scm" > - clock-names: Must contain "core" for the core clock, "iface" for the interface > clock and "bus" for the bus clock per the requirements of the compatible. > +- qcom,dload-mode-addr: Specifies the address (2 cells) for the download mode > + magic (optional) Was it decided that reg was improper? Or a phandle to a node that has a reg property? > > Example for MSM8916: > > diff --git a/drivers/firmware/qcom_scm.c b/drivers/firmware/qcom_scm.c > index e18d63935648..98f4747acddb 100644 > --- a/drivers/firmware/qcom_scm.c > +++ b/drivers/firmware/qcom_scm.c > @@ -19,6 +19,7 @@ > #include <linux/cpumask.h> > #include <linux/export.h> > #include <linux/dma-mapping.h> > +#include <linux/module.h> > #include <linux/types.h> > #include <linux/qcom_scm.h> > #include <linux/of.h> > @@ -28,6 +29,9 @@ > > #include "qcom_scm.h" > > +static bool download_mode; > +module_param(download_mode, bool, 0700); 0700? Not 0600? And what if we have it == 1 on the command line and then write 0 at runtime with module param? Shouldn't we handle that with a callback and turn off download mode there? Otherwise when we reboot we will reboot into download mode? > + > #define SCM_HAS_CORE_CLK BIT(0) > #define SCM_HAS_IFACE_CLK BIT(1) > #define SCM_HAS_BUS_CLK BIT(2) > @@ -365,6 +393,7 @@ static int qcom_scm_probe(struct platform_device *pdev) > struct qcom_scm *scm; > unsigned long clks; > int ret; > + u64 val; > > scm = devm_kzalloc(&pdev->dev, sizeof(*scm), GFP_KERNEL); > if (!scm) > @@ -418,9 +447,22 @@ static int qcom_scm_probe(struct platform_device *pdev) > > __qcom_scm_init(); > > + ret = of_property_read_u64(pdev->dev.of_node, "qcom,dload-mode-addr", &val); > + if (!ret) > + scm->dload_mode_addr = val; How about: of_property_read_u64(pdev->dev.of_node, "qcom,dload-mode-addr", &scm->dload_mode_addr) > + > + if (download_mode) > + qcom_scm_set_download_mode(true); > + > return 0; > } > > +void qcom_scm_shutdown(struct platform_device *pdev) static? > +{ > + if (download_mode) > + qcom_scm_set_download_mode(false); > +} > + -- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project -- To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 05/26, Bjorn Andersson wrote: > The secure IO service provides operations for reading and writing secure > memory from non-secure mode, expose this API through SCM. > > Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org> > --- > > Changes since v1: > - Correct scm-call return value handling > - Make scm_io_readl() return data by reference I'm not sure we ever cared to check the return code of read/write? Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> -- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project -- To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/firmware/qcom_scm-32.c b/drivers/firmware/qcom_scm-32.c index 93e3b96b6dfa..11fdb1584823 100644 --- a/drivers/firmware/qcom_scm-32.c +++ b/drivers/firmware/qcom_scm-32.c @@ -596,3 +596,21 @@ int __qcom_scm_iommu_secure_ptbl_init(struct device *dev, u64 addr, u32 size, { return -ENODEV; } + +int __qcom_scm_io_readl(struct device *dev, phys_addr_t addr, + unsigned int *val) +{ + int ret; + + ret = qcom_scm_call_atomic1(QCOM_SCM_SVC_IO, QCOM_SCM_IO_READ, addr); + if (ret >= 0) + *val = ret; + + return ret < 0 ? ret : 0; +} + +int __qcom_scm_io_writel(struct device *dev, phys_addr_t addr, unsigned int val) +{ + return qcom_scm_call_atomic2(QCOM_SCM_SVC_IO, QCOM_SCM_IO_WRITE, + addr, val); +} diff --git a/drivers/firmware/qcom_scm-64.c b/drivers/firmware/qcom_scm-64.c index 6e6d561708e2..bf50fb59852e 100644 --- a/drivers/firmware/qcom_scm-64.c +++ b/drivers/firmware/qcom_scm-64.c @@ -439,3 +439,34 @@ int __qcom_scm_iommu_secure_ptbl_init(struct device *dev, u64 addr, u32 size, return ret; } + +int __qcom_scm_io_readl(struct device *dev, phys_addr_t addr, + unsigned int *val) +{ + struct qcom_scm_desc desc = {0}; + struct arm_smccc_res res; + int ret; + + desc.args[0] = addr; + desc.arginfo = QCOM_SCM_ARGS(1); + + ret = qcom_scm_call(dev, QCOM_SCM_SVC_IO, QCOM_SCM_IO_READ, + &desc, &res); + if (ret >= 0) + *val = res.a1; + + return ret < 0 ? ret : 0; +} + +int __qcom_scm_io_writel(struct device *dev, phys_addr_t addr, unsigned int val) +{ + struct qcom_scm_desc desc = {0}; + struct arm_smccc_res res; + + desc.args[0] = addr; + desc.args[1] = val; + desc.arginfo = QCOM_SCM_ARGS(2); + + return qcom_scm_call(dev, QCOM_SCM_SVC_IO, QCOM_SCM_IO_WRITE, + &desc, &res); +} diff --git a/drivers/firmware/qcom_scm.c b/drivers/firmware/qcom_scm.c index bb16510d75ba..e18d63935648 100644 --- a/drivers/firmware/qcom_scm.c +++ b/drivers/firmware/qcom_scm.c @@ -333,6 +333,18 @@ int qcom_scm_iommu_secure_ptbl_init(u64 addr, u32 size, u32 spare) } EXPORT_SYMBOL(qcom_scm_iommu_secure_ptbl_init); +int qcom_scm_io_readl(phys_addr_t addr, unsigned int *val) +{ + return __qcom_scm_io_readl(__scm->dev, addr, val); +} +EXPORT_SYMBOL(qcom_scm_io_readl); + +int qcom_scm_io_writel(phys_addr_t addr, unsigned int val) +{ + return __qcom_scm_io_writel(__scm->dev, addr, val); +} +EXPORT_SYMBOL(qcom_scm_io_writel); + /** * qcom_scm_is_available() - Checks if SCM is available */ diff --git a/drivers/firmware/qcom_scm.h b/drivers/firmware/qcom_scm.h index 9bea691f30fb..a60e4b9b1394 100644 --- a/drivers/firmware/qcom_scm.h +++ b/drivers/firmware/qcom_scm.h @@ -30,6 +30,12 @@ extern int __qcom_scm_set_cold_boot_addr(void *entry, const cpumask_t *cpus); #define QCOM_SCM_CMD_CORE_HOTPLUGGED 0x10 extern void __qcom_scm_cpu_power_down(u32 flags); +#define QCOM_SCM_SVC_IO 0x5 +#define QCOM_SCM_IO_READ 0x1 +#define QCOM_SCM_IO_WRITE 0x2 +extern int __qcom_scm_io_readl(struct device *dev, phys_addr_t addr, unsigned int *val); +extern int __qcom_scm_io_writel(struct device *dev, phys_addr_t addr, unsigned int val); + #define QCOM_SCM_SVC_INFO 0x6 #define QCOM_IS_CALL_AVAIL_CMD 0x1 extern int __qcom_scm_is_call_available(struct device *dev, u32 svc_id, diff --git a/include/linux/qcom_scm.h b/include/linux/qcom_scm.h index e5380471c2cd..e8357f570695 100644 --- a/include/linux/qcom_scm.h +++ b/include/linux/qcom_scm.h @@ -43,6 +43,8 @@ extern int qcom_scm_set_remote_state(u32 state, u32 id); extern int qcom_scm_restore_sec_cfg(u32 device_id, u32 spare); extern int qcom_scm_iommu_secure_ptbl_size(u32 spare, size_t *size); extern int qcom_scm_iommu_secure_ptbl_init(u64 addr, u32 size, u32 spare); +extern int qcom_scm_io_readl(phys_addr_t addr, unsigned int *val); +extern int qcom_scm_io_writel(phys_addr_t addr, unsigned int val); #else static inline int qcom_scm_set_cold_boot_addr(void *entry, const cpumask_t *cpus) @@ -73,5 +75,7 @@ qcom_scm_set_remote_state(u32 state,u32 id) { return -ENODEV; } static inline int qcom_scm_restore_sec_cfg(u32 device_id, u32 spare) { return -ENODEV; } static inline int qcom_scm_iommu_secure_ptbl_size(u32 spare, size_t *size) { return -ENODEV; } static inline int qcom_scm_iommu_secure_ptbl_init(u64 addr, u32 size, u32 spare) { return -ENODEV; } +static inline int qcom_scm_io_readl(phys_addr_t addr, unsigned int *val) { return -ENODEV; } +static inline int qcom_scm_io_writel(phys_addr_t addr, unsigned int val) { return -ENODEV; } #endif #endif
The secure IO service provides operations for reading and writing secure memory from non-secure mode, expose this API through SCM. Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org> --- Changes since v1: - Correct scm-call return value handling - Make scm_io_readl() return data by reference drivers/firmware/qcom_scm-32.c | 18 ++++++++++++++++++ drivers/firmware/qcom_scm-64.c | 31 +++++++++++++++++++++++++++++++ drivers/firmware/qcom_scm.c | 12 ++++++++++++ drivers/firmware/qcom_scm.h | 6 ++++++ include/linux/qcom_scm.h | 4 ++++ 5 files changed, 71 insertions(+) -- 2.12.0 -- To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html