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charset=us-ascii Content-Disposition: inline In-Reply-To: <20241023092251529-0700.eberman@hu-eberman-lv.qualcomm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20241115_053603_405514_B063F727 X-CRM114-Status: GOOD ( 32.73 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Wed, Oct 23, 2024 at 09:30:21AM -0700, Elliot Berman wrote: > On Fri, Oct 18, 2024 at 10:42:46PM -0700, Stephen Boyd wrote: > > Quoting Elliot Berman (2024-10-18 12:39:48) > > > diff --git a/drivers/firmware/psci/psci.c b/drivers/firmware/psci/psci.c > > > index 2328ca58bba6..60bc285622ce 100644 > > > --- a/drivers/firmware/psci/psci.c > > > +++ b/drivers/firmware/psci/psci.c > > > @@ -29,6 +29,8 @@ > > > #include > > > #include > > > > > > +#define REBOOT_PREFIX "mode-" > > > > Maybe move this near the function that uses it. > > > > > + > > > /* > > > * While a 64-bit OS can make calls with SMC32 calling conventions, for some > > > * calls it is necessary to use SMC64 to pass or return 64-bit values. > > > @@ -305,9 +315,29 @@ static int get_set_conduit_method(const struct device_node *np) > > > return 0; > > > } > > > > > > +static void psci_vendor_sys_reset2(unsigned long action, void *data) > > > +{ > > > + const char *cmd = data; > > > + unsigned long ret; > > > + size_t i; > > > + > > > + for (i = 0; i < num_psci_reset_params; i++) { > > > + if (!strcmp(psci_reset_params[i].mode, cmd)) { > > > + ret = invoke_psci_fn(PSCI_FN_NATIVE(1_1, SYSTEM_RESET2), > > > + psci_reset_params[i].reset_type, > > > + psci_reset_params[i].cookie, 0); > > > + pr_err("failed to perform reset \"%s\": %ld\n", > > > + cmd, (long)ret); > > > > Do this intentionally return? Should it be some other function that's > > __noreturn instead and a while (1) if the firmware returns back to the > > kernel? > > > > Yes, I think it's best to make sure we fall back to the architectural > reset (whether it's the SYSTEM_RESET or architectural SYSTEM_RESET2) > since device would reboot then. Well, that's one of the doubts I have about enabling this code. From userspace we are requesting a reboot (I don't even think that user space knows which reboot modes are actually implemented (?)) and we may end up issuing one with completely different semantics ? Are these "reset types" exported to user space ? Lorenzo > > > + } > > > + } > > > +} > > > + > > > static int psci_sys_reset(struct notifier_block *nb, unsigned long action, > > > void *data) > > > { > > > + if (data && num_psci_reset_params) > > > + psci_vendor_sys_reset2(action, data); > > > + > > > if ((reboot_mode == REBOOT_WARM || reboot_mode == REBOOT_SOFT) && > > > psci_system_reset2_supported) { > > > /* > > > @@ -750,6 +780,68 @@ static const struct of_device_id psci_of_match[] __initconst = { > > > {}, > > > }; > > > > > > +static int __init psci_init_system_reset2_modes(void) > > > +{ > > > + const size_t len = strlen(REBOOT_PREFIX); > > > + struct psci_reset_param *param; > > > + struct device_node *psci_np __free(device_node) = NULL; > > > + struct device_node *np __free(device_node) = NULL; > > > + struct property *prop; > > > + size_t count = 0; > > > + u32 magic[2]; > > > + int num; > > > + > > > + if (!psci_system_reset2_supported) > > > + return 0; > > > + > > > + psci_np = of_find_matching_node(NULL, psci_of_match); > > > + if (!psci_np) > > > + return 0; > > > + > > > + np = of_find_node_by_name(psci_np, "reset-types"); > > > + if (!np) > > > + return 0; > > > + > > > + for_each_property_of_node(np, prop) { > > > + if (strncmp(prop->name, REBOOT_PREFIX, len)) > > > + continue; > > > + num = of_property_count_elems_of_size(np, prop->name, sizeof(magic[0])); > > > > Use of_property_count_u32_elems()? > > > > > + if (num != 1 && num != 2) > > > + continue; > > > + > > > + count++; > > > + } > > > + > > > + param = psci_reset_params = kcalloc(count, sizeof(*psci_reset_params), GFP_KERNEL); > > > + if (!psci_reset_params) > > > + return -ENOMEM; > > > + > > > + for_each_property_of_node(np, prop) { > > > + if (strncmp(prop->name, REBOOT_PREFIX, len)) > > > + continue; > > > + > > > + param->mode = kstrdup_const(prop->name + len, GFP_KERNEL); > > > + if (!param->mode) > > > + continue; > > > + > > > + num = of_property_read_variable_u32_array(np, prop->name, magic, 1, 2); > > > > ARRAY_SIZE(magic)? > > > > > + if (num < 0) { > > > > Should this be less than 1? > > > > of_property_read_variable_u32_array should return -EOVERFLOW (or maybe > -ENODATA) if the array is empty. I don't see it's possible for > of_property_read_variable_u32_array() to return a non-negative value > that's not 1 or 2. > > > > + pr_warn("Failed to parse vendor reboot mode %s\n", param->mode); > > > + kfree_const(param->mode); > > > + continue; > > > + } > > > + > > > + /* Force reset type to be in vendor space */ > > > + param->reset_type = PSCI_1_1_RESET_TYPE_VENDOR_START | magic[0]; > > > + param->cookie = num == 2 ? magic[1] : 0; > > > > ARRAY_SIZE(magic)? > > > > > + param++; > > > + num_psci_reset_params++; > > > + } > > > + > > > + return 0;