On Sat, May 13, 2017 at 1:07 AM, Ruchika Gupta <ruchika.gu...@nxp.com> wrote:
> kASLR support in kernel requires a random number to be passed via
> chosen/kaslr-seed propert. sec_firmware generates this random seed
> which can then be passed in the device tree node
Is that functionality generic that it can be consumed by other devices?
> sec_firmware reserves JR3 for it's own usage. Node for JR3 is
> removed from device-tree.
>
> Signed-off-by: Ruchika Gupta <ruchika.gu...@nxp.com>
> ---
> arch/arm/cpu/armv8/fsl-layerscape/fdt.c | 73
> +++++++++++++++++++++++++++++++
> arch/arm/cpu/armv8/sec_firmware.c | 53 ++++++++++++++++++++++
> arch/arm/include/asm/armv8/sec_firmware.h | 9 ++++
> 3 files changed, 135 insertions(+)
>
> diff --git a/arch/arm/cpu/armv8/fsl-layerscape/fdt.c
> b/arch/arm/cpu/armv8/fsl-layerscape/fdt.c
> index 05c4577..d4ca129 100644
> --- a/arch/arm/cpu/armv8/fsl-layerscape/fdt.c
> +++ b/arch/arm/cpu/armv8/fsl-layerscape/fdt.c
> @@ -345,6 +345,75 @@ static void fdt_fixup_msi(void *blob)
> }
> #endif
>
> +
> +int fdt_fixup_kaslr(void *fdt)
> +{
> + int nodeoffset;
> + int err, ret = 0;
> + u8 rand[8];
> +
> +#if defined(CONFIG_ARMV8_SEC_FIRMWARE_SUPPORT)
> + /* Check if random seed generation is supported */
> + if (sec_firmware_support_hwrng() == false)
> + return 0;
> +
> + ret = sec_firmware_get_random(rand, 8);
> + if (ret < 0) {
> + printf("WARNING: could not get random number to set",
> + "kaslr-seed\n");
> + return 0;
> + }
> +
> + err = fdt_check_header(fdt);
> + if (err < 0) {
> + printf("fdt_chosen: %s\n", fdt_strerror(err));
> + return 0;
> + }
> +
> + /* find or create "/chosen" node. */
> + nodeoffset = fdt_find_or_add_subnode(fdt, 0, "chosen");
> + if (nodeoffset < 0)
> + return 0;
> +
> + err = fdt_setprop(fdt, nodeoffset, "kaslr-seed", rand,
> + sizeof(rand));
> + if (err < 0) {
> + printf("WARNING: could not set kaslr-seed %s.\n",
> + fdt_strerror(err));
> + return 0;
> + }
> + ret = 1;
> +#endif
> +
> + return ret;
> +}
> +
> +/* Remove JR node used by SEC firmware */
> +void fdt_fixup_remove_jr(void *blob)
> +{
> + int jr_node, addr_cells, len;
> + int crypto_node = fdt_path_offset(blob, "crypto");
> + u64 jr_offset, used_jr;
> + fdt32_t *reg;
> +
> + used_jr = sec_firmware_used_jobring_offset();
> + of_bus_default_count_cells(blob, crypto_node, &addr_cells, NULL);
> +
> + jr_node = fdt_node_offset_by_compatible(blob, crypto_node,
> + "fsl,sec-v4.0-job-ring");
> +
> + while (jr_node != -FDT_ERR_NOTFOUND) {
> + reg = (fdt32_t *)fdt_getprop(blob, jr_node, "reg", &len);
> + jr_offset = of_read_number(reg, addr_cells);
> + if (jr_offset == used_jr) {
> + fdt_del_node(blob, jr_node);
> + break;
> + }
> + jr_node = fdt_node_offset_by_compatible(blob, jr_node,
> +
> "fsl,sec-v4.0-job-ring");
> + }
> +}
> +
> void ft_cpu_setup(void *blob, bd_t *bd)
> {
> #ifdef CONFIG_FSL_LSCH2
> @@ -358,6 +427,9 @@ void ft_cpu_setup(void *blob, bd_t *bd)
> else {
> ccsr_sec_t __iomem *sec;
>
> + if (fdt_fixup_kaslr(blob))
> + fdt_fixup_remove_jr(blob);
> +
> sec = (void __iomem *)CONFIG_SYS_FSL_SEC_ADDR;
> fdt_fixup_crypto_node(blob, sec_in32(&sec->secvid_ms));
> }
> @@ -396,4 +468,5 @@ void ft_cpu_setup(void *blob, bd_t *bd)
> #ifdef CONFIG_HAS_FEATURE_ENHANCED_MSI
> fdt_fixup_msi(blob);
> #endif
> +
> }
> diff --git a/arch/arm/cpu/armv8/sec_firmware.c
> b/arch/arm/cpu/armv8/sec_firmware.c
> index 4afa3ad..f460cca 100644
> --- a/arch/arm/cpu/armv8/sec_firmware.c
> +++ b/arch/arm/cpu/armv8/sec_firmware.c
> @@ -232,6 +232,59 @@ unsigned int sec_firmware_support_psci_version(void)
> #endif
>
> /*
> + * Check with sec_firmware if it supports random number generation
> + * via HW RNG
> + *
> + * The return value will be true if it is supported
> + */
> +bool sec_firmware_support_hwrng(void)
> +{
> + uint8_t rand[8];
> + if (sec_firmware_addr & SEC_FIRMWARE_RUNNING) {
> + if (!sec_firmware_get_random(rand, 8))
> + return true;
> + }
> +
> + return false;
> +}
> +
> +/*
> + * sec_firmware_get_random - Initialize the SEC Firmware
> + * @rand: random number buffer to be filled
> + * @bytes: Number of bytes of random number to be supported
> + * @eret: -1 in case of error, 0 for success
> + */
> +int sec_firmware_get_random(uint8_t *rand, int bytes)
> +{
> + unsigned long long num;
> + struct pt_regs regs;
> + int param1;
> +
> + if (!bytes || bytes > 8) {
> + printf("Max Random bytes genration supported is 8\n");
> + return -1;
> + }
> +#define SIP_RNG_64 0xC200FF11
> + regs.regs[0] = SIP_RNG_64;
> +
> + if (bytes <= 4)
> + param1 = 0;
> + else
> + param1 = 1;
> + regs.regs[1] = param1;
> +
> + smc_call(®s);
> +
> + if (regs.regs[0])
> + return -1;
> +
> + num = regs.regs[1];
> + memcpy(rand, &num, bytes);
> +
> + return 0;
> +}
> +
> +/*
> * sec_firmware_init - Initialize the SEC Firmware
> * @sec_firmware_img: the SEC Firmware image address
> * @eret_hold_l: the address to hold exception return address low
> diff --git a/arch/arm/include/asm/armv8/sec_firmware.h
> b/arch/arm/include/asm/armv8/sec_firmware.h
> index bc1d97d..1dc547a 100644
> --- a/arch/arm/include/asm/armv8/sec_firmware.h
> +++ b/arch/arm/include/asm/armv8/sec_firmware.h
> @@ -8,10 +8,13 @@
> #define __SEC_FIRMWARE_H_
>
> #define PSCI_INVALID_VER 0xffffffff
> +#define SEC_JR3_OFFSET 0x40000
>
> int sec_firmware_init(const void *, u32 *, u32 *);
> int _sec_firmware_entry(const void *, u32 *, u32 *);
> bool sec_firmware_is_valid(const void *);
> +bool sec_firmware_support_hwrng(void);
> +int sec_firmware_get_random(uint8_t *rand, int bytes);
> #ifdef CONFIG_SEC_FIRMWARE_ARMV8_PSCI
> unsigned int sec_firmware_support_psci_version(void);
> unsigned int _sec_firmware_support_psci_version(void);
> @@ -22,4 +25,10 @@ static inline unsigned int
> sec_firmware_support_psci_version(void)
> }
> #endif
>
> +static inline unsigned int sec_firmware_used_jobring_offset(void)
> +{
> + return SEC_JR3_OFFSET;
> +}
> +
> +
> #endif /* __SEC_FIRMWARE_H_ */
> --
> 2.7.4
>
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