xref: /rk3399_ARM-atf/plat/xilinx/versal/plat_psci.c (revision 435bc14a94008ab811ebac2735875a99ea6e464c)
1f91c3cb1SSiva Durga Prasad Paladugu /*
2619bc13eSMichal Simek  * Copyright (c) 2018-2021, Arm Limited and Contributors. All rights reserved.
3652c1ab1SMichal Simek  * Copyright (c) 2022-2024, Advanced Micro Devices, Inc. All rights reserved.
4f91c3cb1SSiva Durga Prasad Paladugu  *
5f91c3cb1SSiva Durga Prasad Paladugu  * SPDX-License-Identifier: BSD-3-Clause
6f91c3cb1SSiva Durga Prasad Paladugu  */
7f91c3cb1SSiva Durga Prasad Paladugu 
85a8ffeabSTejas Patel #include <assert.h>
901a326abSPrasad Kummari 
1009d40e0eSAntonio Nino Diaz #include <common/debug.h>
1109d40e0eSAntonio Nino Diaz #include <lib/mmio.h>
1209d40e0eSAntonio Nino Diaz #include <lib/psci/psci.h>
130abf4bbaSSaeed Nowshadi #include <plat/arm/common/plat_arm.h>
1401a326abSPrasad Kummari #include <plat/common/platform.h>
1501a326abSPrasad Kummari #include <plat_arm.h>
1609d40e0eSAntonio Nino Diaz 
1788ee0816SJay Buddhabhatti #include "drivers/delay_timer.h"
1801a326abSPrasad Kummari #include <plat_private.h>
19394a65aaSTejas Patel #include "pm_api_sys.h"
20394a65aaSTejas Patel #include "pm_client.h"
2101a326abSPrasad Kummari #include <pm_common.h>
2288ee0816SJay Buddhabhatti #include "pm_ipi.h"
2388ee0816SJay Buddhabhatti #include "pm_svc_main.h"
24394a65aaSTejas Patel 
25f91c3cb1SSiva Durga Prasad Paladugu static uintptr_t versal_sec_entry;
26f91c3cb1SSiva Durga Prasad Paladugu 
27912b7a6fSVenkatesh Yadav Abbarapu static int32_t versal_pwr_domain_on(u_register_t mpidr)
28f91c3cb1SSiva Durga Prasad Paladugu {
29912b7a6fSVenkatesh Yadav Abbarapu 	int32_t cpu_id = plat_core_pos_by_mpidr(mpidr);
30394a65aaSTejas Patel 	const struct pm_proc *proc;
31890781d1SMaheedhar Bollapalli 	int32_t ret = PSCI_E_INTERN_FAIL;
32f91c3cb1SSiva Durga Prasad Paladugu 
33f91c3cb1SSiva Durga Prasad Paladugu 	VERBOSE("%s: mpidr: 0x%lx\n", __func__, mpidr);
34f91c3cb1SSiva Durga Prasad Paladugu 
35b9fa2d9fSAbhyuday Godhasara 	if (cpu_id == -1) {
36890781d1SMaheedhar Bollapalli 		goto exit_label;
37b9fa2d9fSAbhyuday Godhasara 	}
38f91c3cb1SSiva Durga Prasad Paladugu 
39912b7a6fSVenkatesh Yadav Abbarapu 	proc = pm_get_proc((uint32_t)cpu_id);
40655e62aaSRonak Jain 	if (proc == NULL) {
41890781d1SMaheedhar Bollapalli 		goto exit_label;
42652c1ab1SMichal Simek 	}
43f91c3cb1SSiva Durga Prasad Paladugu 
44394a65aaSTejas Patel 	/* Send request to PMC to wake up selected ACPU core */
45526a1fd1SAbhyuday Godhasara 	(void)pm_req_wakeup(proc->node_id, (versal_sec_entry & 0xFFFFFFFFU) | 0x1U,
464697164aSTejas Patel 			    versal_sec_entry >> 32, 0, SECURE_FLAG);
47f91c3cb1SSiva Durga Prasad Paladugu 
48394a65aaSTejas Patel 	/* Clear power down request */
49394a65aaSTejas Patel 	pm_client_wakeup(proc);
50f91c3cb1SSiva Durga Prasad Paladugu 
51890781d1SMaheedhar Bollapalli 	ret = PSCI_E_SUCCESS;
52890781d1SMaheedhar Bollapalli 
53890781d1SMaheedhar Bollapalli exit_label:
54890781d1SMaheedhar Bollapalli 	return ret;
55f91c3cb1SSiva Durga Prasad Paladugu }
56f91c3cb1SSiva Durga Prasad Paladugu 
575a8ffeabSTejas Patel /**
585a8ffeabSTejas Patel  * versal_pwr_domain_suspend() - This function sends request to PMC to suspend
595a8ffeabSTejas Patel  *                               core.
60de7ed953SPrasad Kummari  * @target_state: Targated state.
615a8ffeabSTejas Patel  *
625a8ffeabSTejas Patel  */
635a8ffeabSTejas Patel static void versal_pwr_domain_suspend(const psci_power_state_t *target_state)
645a8ffeabSTejas Patel {
65912b7a6fSVenkatesh Yadav Abbarapu 	uint32_t state;
66912b7a6fSVenkatesh Yadav Abbarapu 	uint32_t cpu_id = plat_my_core_pos();
675a8ffeabSTejas Patel 	const struct pm_proc *proc = pm_get_proc(cpu_id);
685a8ffeabSTejas Patel 
69655e62aaSRonak Jain 	if (proc == NULL) {
70652c1ab1SMichal Simek 		return;
71652c1ab1SMichal Simek 	}
72652c1ab1SMichal Simek 
730623dceaSAbhyuday Godhasara 	for (size_t i = 0U; i <= PLAT_MAX_PWR_LVL; i++) {
745a8ffeabSTejas Patel 		VERBOSE("%s: target_state->pwr_domain_state[%lu]=%x\n",
755a8ffeabSTejas Patel 			__func__, i, target_state->pwr_domain_state[i]);
76b9fa2d9fSAbhyuday Godhasara 	}
775a8ffeabSTejas Patel 
785a8ffeabSTejas Patel 	plat_versal_gic_cpuif_disable();
795a8ffeabSTejas Patel 
80d4c7b550SRavi Patel 	if (target_state->pwr_domain_state[1] > PLAT_MAX_RET_STATE) {
815a8ffeabSTejas Patel 		plat_versal_gic_save();
82d4c7b550SRavi Patel 	}
835a8ffeabSTejas Patel 
840ed8b4bfSMaheedhar Bollapalli 	state = (target_state->pwr_domain_state[1] > PLAT_MAX_RET_STATE) ?
855a8ffeabSTejas Patel 		PM_STATE_SUSPEND_TO_RAM : PM_STATE_CPU_IDLE;
865a8ffeabSTejas Patel 
875a8ffeabSTejas Patel 	/* Send request to PMC to suspend this core */
88526a1fd1SAbhyuday Godhasara 	(void)pm_self_suspend(proc->node_id, MAX_LATENCY, state, versal_sec_entry,
894697164aSTejas Patel 			      SECURE_FLAG);
905a8ffeabSTejas Patel 
915a8ffeabSTejas Patel 	/* APU is to be turned off */
925a8ffeabSTejas Patel 	if (target_state->pwr_domain_state[1] > PLAT_MAX_RET_STATE) {
935a8ffeabSTejas Patel 		/* disable coherency */
945a8ffeabSTejas Patel 		plat_arm_interconnect_exit_coherency();
955a8ffeabSTejas Patel 	}
965a8ffeabSTejas Patel }
975a8ffeabSTejas Patel 
985a8ffeabSTejas Patel /**
995a8ffeabSTejas Patel  * versal_pwr_domain_suspend_finish() - This function performs actions to finish
1005a8ffeabSTejas Patel  *                                      suspend procedure.
101de7ed953SPrasad Kummari  * @target_state: Targated state.
1025a8ffeabSTejas Patel  *
1035a8ffeabSTejas Patel  */
1045a8ffeabSTejas Patel static void versal_pwr_domain_suspend_finish(
1055a8ffeabSTejas Patel 					const psci_power_state_t *target_state)
1065a8ffeabSTejas Patel {
107912b7a6fSVenkatesh Yadav Abbarapu 	uint32_t cpu_id = plat_my_core_pos();
1085a8ffeabSTejas Patel 	const struct pm_proc *proc = pm_get_proc(cpu_id);
1095a8ffeabSTejas Patel 
110655e62aaSRonak Jain 	if (proc == NULL) {
111652c1ab1SMichal Simek 		return;
112652c1ab1SMichal Simek 	}
113652c1ab1SMichal Simek 
1140623dceaSAbhyuday Godhasara 	for (size_t i = 0U; i <= PLAT_MAX_PWR_LVL; i++) {
1155a8ffeabSTejas Patel 		VERBOSE("%s: target_state->pwr_domain_state[%lu]=%x\n",
1165a8ffeabSTejas Patel 			__func__, i, target_state->pwr_domain_state[i]);
117b9fa2d9fSAbhyuday Godhasara 	}
1185a8ffeabSTejas Patel 
1195a8ffeabSTejas Patel 	/* Clear the APU power control register for this cpu */
1205a8ffeabSTejas Patel 	pm_client_wakeup(proc);
1215a8ffeabSTejas Patel 
1225a8ffeabSTejas Patel 	/* enable coherency */
1235a8ffeabSTejas Patel 	plat_arm_interconnect_enter_coherency();
1245a8ffeabSTejas Patel 
1255a8ffeabSTejas Patel 	/* APU was turned off, so restore GIC context */
1265a8ffeabSTejas Patel 	if (target_state->pwr_domain_state[1] > PLAT_MAX_RET_STATE) {
1275a8ffeabSTejas Patel 		plat_versal_gic_resume();
1285a8ffeabSTejas Patel 	}
129d4c7b550SRavi Patel 
130d4c7b550SRavi Patel 	plat_versal_gic_cpuif_enable();
1315a8ffeabSTejas Patel }
1325a8ffeabSTejas Patel 
13316c611f8SMaheedhar Bollapalli static void versal_pwr_domain_on_finish(const psci_power_state_t *target_state)
134f91c3cb1SSiva Durga Prasad Paladugu {
135f91c3cb1SSiva Durga Prasad Paladugu 	/* Enable the gic cpu interface */
136f91c3cb1SSiva Durga Prasad Paladugu 	plat_versal_gic_pcpu_init();
137f91c3cb1SSiva Durga Prasad Paladugu 
138f91c3cb1SSiva Durga Prasad Paladugu 	/* Program the gic per-cpu distributor or re-distributor interface */
139f91c3cb1SSiva Durga Prasad Paladugu 	plat_versal_gic_cpuif_enable();
140f91c3cb1SSiva Durga Prasad Paladugu }
141f91c3cb1SSiva Durga Prasad Paladugu 
1425a8ffeabSTejas Patel /**
143de7ed953SPrasad Kummari  * versal_system_off() - This function sends the system off request to firmware.
144de7ed953SPrasad Kummari  *                       This function does not return.
145de7ed953SPrasad Kummari  *
1460abf4bbaSSaeed Nowshadi  */
1470abf4bbaSSaeed Nowshadi static void __dead2 versal_system_off(void)
1480abf4bbaSSaeed Nowshadi {
1490abf4bbaSSaeed Nowshadi 	/* Send the power down request to the PMC */
150526a1fd1SAbhyuday Godhasara 	(void)pm_system_shutdown(XPM_SHUTDOWN_TYPE_SHUTDOWN,
1514697164aSTejas Patel 				 pm_get_shutdown_scope(), SECURE_FLAG);
1520abf4bbaSSaeed Nowshadi 
15312475663SMaheedhar Bollapalli 	while (true) {
1540abf4bbaSSaeed Nowshadi 		wfi();
1550abf4bbaSSaeed Nowshadi 	}
156b9fa2d9fSAbhyuday Godhasara }
1570abf4bbaSSaeed Nowshadi 
1580abf4bbaSSaeed Nowshadi /**
159de7ed953SPrasad Kummari  * versal_system_reset() - This function sends the reset request to firmware
160de7ed953SPrasad Kummari  *                         for the system to reset.  This function does not
161de7ed953SPrasad Kummari  *			   return.
162de7ed953SPrasad Kummari  *
1630abf4bbaSSaeed Nowshadi  */
1640abf4bbaSSaeed Nowshadi static void __dead2 versal_system_reset(void)
1650abf4bbaSSaeed Nowshadi {
16688ee0816SJay Buddhabhatti 	uint32_t ret, timeout = 10000U;
16788ee0816SJay Buddhabhatti 
16888ee0816SJay Buddhabhatti 	request_cpu_pwrdwn();
16988ee0816SJay Buddhabhatti 
17088ee0816SJay Buddhabhatti 	/*
17188ee0816SJay Buddhabhatti 	 * Send the system reset request to the firmware if power down request
17288ee0816SJay Buddhabhatti 	 * is not received from firmware.
17388ee0816SJay Buddhabhatti 	 */
17488ee0816SJay Buddhabhatti 	if (!pwrdwn_req_received) {
175526a1fd1SAbhyuday Godhasara 		(void)pm_system_shutdown(XPM_SHUTDOWN_TYPE_RESET,
1764697164aSTejas Patel 					 pm_get_shutdown_scope(), SECURE_FLAG);
1770abf4bbaSSaeed Nowshadi 
17888ee0816SJay Buddhabhatti 		/*
17988ee0816SJay Buddhabhatti 		 * Wait for system shutdown request completed and idle callback
18088ee0816SJay Buddhabhatti 		 * not received.
18188ee0816SJay Buddhabhatti 		 */
18288ee0816SJay Buddhabhatti 		do {
18388ee0816SJay Buddhabhatti 			ret = ipi_mb_enquire_status(primary_proc->ipi->local_ipi_id,
18488ee0816SJay Buddhabhatti 						    primary_proc->ipi->remote_ipi_id);
18588ee0816SJay Buddhabhatti 			udelay(100);
18688ee0816SJay Buddhabhatti 			timeout--;
18788ee0816SJay Buddhabhatti 		} while ((ret != IPI_MB_STATUS_RECV_PENDING) && (timeout > 0U));
18888ee0816SJay Buddhabhatti 	}
18988ee0816SJay Buddhabhatti 
19088ee0816SJay Buddhabhatti 	(void)psci_cpu_off();
19188ee0816SJay Buddhabhatti 
19212475663SMaheedhar Bollapalli 	while (true) {
1930abf4bbaSSaeed Nowshadi 		wfi();
1940abf4bbaSSaeed Nowshadi 	}
195b9fa2d9fSAbhyuday Godhasara }
1960abf4bbaSSaeed Nowshadi 
197*435bc14aSMaheedhar Bollapalli static int32_t versal_validate_ns_entrypoint(uint64_t ns_entrypoint)
198*435bc14aSMaheedhar Bollapalli {
199*435bc14aSMaheedhar Bollapalli 	int32_t ret = PSCI_E_SUCCESS;
200*435bc14aSMaheedhar Bollapalli 
201*435bc14aSMaheedhar Bollapalli 	if (((ns_entrypoint >= PLAT_DDR_LOWMEM_MAX) && (ns_entrypoint <= PLAT_DDR_HIGHMEM_MAX)) ||
202*435bc14aSMaheedhar Bollapalli 		((ns_entrypoint >= BL31_BASE) && (ns_entrypoint <= BL31_LIMIT))) {
203*435bc14aSMaheedhar Bollapalli 		ret = PSCI_E_INVALID_ADDRESS;
204*435bc14aSMaheedhar Bollapalli 	}
205*435bc14aSMaheedhar Bollapalli 
206*435bc14aSMaheedhar Bollapalli 	return ret;
207*435bc14aSMaheedhar Bollapalli }
208*435bc14aSMaheedhar Bollapalli 
2090abf4bbaSSaeed Nowshadi /**
210de7ed953SPrasad Kummari  * versal_pwr_domain_off() - This function performs actions to turn off core.
211de7ed953SPrasad Kummari  * @target_state: Targated state.
2125a8ffeabSTejas Patel  *
2135a8ffeabSTejas Patel  */
2145a8ffeabSTejas Patel static void versal_pwr_domain_off(const psci_power_state_t *target_state)
2155a8ffeabSTejas Patel {
216e452826aSMaheedhar Bollapalli 	uint32_t ret, fw_api_version, version_type[RET_PAYLOAD_ARG_CNT] = {0U};
217912b7a6fSVenkatesh Yadav Abbarapu 	uint32_t cpu_id = plat_my_core_pos();
2185a8ffeabSTejas Patel 	const struct pm_proc *proc = pm_get_proc(cpu_id);
2195a8ffeabSTejas Patel 
220655e62aaSRonak Jain 	if (proc == NULL) {
221652c1ab1SMichal Simek 		return;
222652c1ab1SMichal Simek 	}
223652c1ab1SMichal Simek 
2240623dceaSAbhyuday Godhasara 	for (size_t i = 0U; i <= PLAT_MAX_PWR_LVL; i++) {
2255a8ffeabSTejas Patel 		VERBOSE("%s: target_state->pwr_domain_state[%lu]=%x\n",
2265a8ffeabSTejas Patel 			__func__, i, target_state->pwr_domain_state[i]);
227b9fa2d9fSAbhyuday Godhasara 	}
2285a8ffeabSTejas Patel 
2295a8ffeabSTejas Patel 	/* Prevent interrupts from spuriously waking up this cpu */
2305a8ffeabSTejas Patel 	plat_versal_gic_cpuif_disable();
2315a8ffeabSTejas Patel 
2325a8ffeabSTejas Patel 	/*
2335a8ffeabSTejas Patel 	 * Send request to PMC to power down the appropriate APU CPU
2345a8ffeabSTejas Patel 	 * core.
2355a8ffeabSTejas Patel 	 * According to PSCI specification, CPU_off function does not
2365a8ffeabSTejas Patel 	 * have resume address and CPU core can only be woken up
2375a8ffeabSTejas Patel 	 * invoking CPU_on function, during which resume address will
2385a8ffeabSTejas Patel 	 * be set.
2395a8ffeabSTejas Patel 	 */
240e452826aSMaheedhar Bollapalli 	ret = pm_feature_check((uint32_t)PM_SELF_SUSPEND, &version_type[0], SECURE_FLAG);
241b802b278SMaheedhar Bollapalli 	if (ret == (uint32_t)PM_RET_SUCCESS) {
242e452826aSMaheedhar Bollapalli 		fw_api_version = version_type[0] & 0xFFFFU;
24359497016SJay Buddhabhatti 		if (fw_api_version >= 3U) {
24459497016SJay Buddhabhatti 			(void)pm_self_suspend(proc->node_id, MAX_LATENCY, PM_STATE_CPU_OFF, 0,
24559497016SJay Buddhabhatti 					      SECURE_FLAG);
24659497016SJay Buddhabhatti 		} else {
247526a1fd1SAbhyuday Godhasara 			(void)pm_self_suspend(proc->node_id, MAX_LATENCY, PM_STATE_CPU_IDLE, 0,
2484697164aSTejas Patel 					      SECURE_FLAG);
2495a8ffeabSTejas Patel 		}
25059497016SJay Buddhabhatti 	}
25159497016SJay Buddhabhatti }
2525a8ffeabSTejas Patel 
2535a8ffeabSTejas Patel /**
2545a8ffeabSTejas Patel  * versal_validate_power_state() - This function ensures that the power state
2555a8ffeabSTejas Patel  *                                 parameter in request is valid.
256de7ed953SPrasad Kummari  * @power_state: Power state of core.
257de7ed953SPrasad Kummari  * @req_state: Requested state.
2585a8ffeabSTejas Patel  *
259de7ed953SPrasad Kummari  * Return: Returns status, either success or reason.
2605a8ffeabSTejas Patel  *
2615a8ffeabSTejas Patel  */
262912b7a6fSVenkatesh Yadav Abbarapu static int32_t versal_validate_power_state(uint32_t power_state,
2635a8ffeabSTejas Patel 				       psci_power_state_t *req_state)
2645a8ffeabSTejas Patel {
265890781d1SMaheedhar Bollapalli 	int32_t ret = PSCI_E_SUCCESS;
2665a8ffeabSTejas Patel 	VERBOSE("%s: power_state: 0x%x\n", __func__, power_state);
2675a8ffeabSTejas Patel 
268912b7a6fSVenkatesh Yadav Abbarapu 	uint32_t pstate = psci_get_pstate_type(power_state);
2695a8ffeabSTejas Patel 
270b39c82e9SMaheedhar Bollapalli 	assert(req_state != NULL);
2715a8ffeabSTejas Patel 
2725a8ffeabSTejas Patel 	/* Sanity check the requested state */
273b9fa2d9fSAbhyuday Godhasara 	if (pstate == PSTATE_TYPE_STANDBY) {
2745a8ffeabSTejas Patel 		req_state->pwr_domain_state[MPIDR_AFFLVL0] = PLAT_MAX_RET_STATE;
275b9fa2d9fSAbhyuday Godhasara 	} else {
2765a8ffeabSTejas Patel 		req_state->pwr_domain_state[MPIDR_AFFLVL0] = PLAT_MAX_OFF_STATE;
277b9fa2d9fSAbhyuday Godhasara 	}
2785a8ffeabSTejas Patel 
2795a8ffeabSTejas Patel 	/* We expect the 'state id' to be zero */
280a62c40d4SAbhyuday Godhasara 	if (psci_get_pstate_id(power_state) != 0U) {
281890781d1SMaheedhar Bollapalli 		ret = PSCI_E_INVALID_PARAMS;
282b9fa2d9fSAbhyuday Godhasara 	}
2835a8ffeabSTejas Patel 
284890781d1SMaheedhar Bollapalli 	return ret;
2855a8ffeabSTejas Patel }
2865a8ffeabSTejas Patel 
2875a8ffeabSTejas Patel /**
288de7ed953SPrasad Kummari  * versal_get_sys_suspend_power_state() - Get power state for system suspend.
289de7ed953SPrasad Kummari  * @req_state: Requested state.
2905a8ffeabSTejas Patel  *
2915a8ffeabSTejas Patel  */
2925a8ffeabSTejas Patel static void versal_get_sys_suspend_power_state(psci_power_state_t *req_state)
2935a8ffeabSTejas Patel {
2945a8ffeabSTejas Patel 	req_state->pwr_domain_state[PSCI_CPU_PWR_LVL] = PLAT_MAX_OFF_STATE;
2955a8ffeabSTejas Patel 	req_state->pwr_domain_state[1] = PLAT_MAX_OFF_STATE;
2965a8ffeabSTejas Patel }
2975a8ffeabSTejas Patel 
298f91c3cb1SSiva Durga Prasad Paladugu static const struct plat_psci_ops versal_nopmc_psci_ops = {
299394a65aaSTejas Patel 	.pwr_domain_on			= versal_pwr_domain_on,
3005a8ffeabSTejas Patel 	.pwr_domain_off			= versal_pwr_domain_off,
301f91c3cb1SSiva Durga Prasad Paladugu 	.pwr_domain_on_finish		= versal_pwr_domain_on_finish,
3025a8ffeabSTejas Patel 	.pwr_domain_suspend		= versal_pwr_domain_suspend,
3035a8ffeabSTejas Patel 	.pwr_domain_suspend_finish	= versal_pwr_domain_suspend_finish,
3040abf4bbaSSaeed Nowshadi 	.system_off			= versal_system_off,
3050abf4bbaSSaeed Nowshadi 	.system_reset			= versal_system_reset,
306*435bc14aSMaheedhar Bollapalli 	.validate_ns_entrypoint		= versal_validate_ns_entrypoint,
3075a8ffeabSTejas Patel 	.validate_power_state		= versal_validate_power_state,
3085a8ffeabSTejas Patel 	.get_sys_suspend_power_state	= versal_get_sys_suspend_power_state,
309f91c3cb1SSiva Durga Prasad Paladugu };
310f91c3cb1SSiva Durga Prasad Paladugu 
311f91c3cb1SSiva Durga Prasad Paladugu /*******************************************************************************
312f91c3cb1SSiva Durga Prasad Paladugu  * Export the platform specific power ops.
313f91c3cb1SSiva Durga Prasad Paladugu  ******************************************************************************/
314f7c48d9eSVenkatesh Yadav Abbarapu int32_t plat_setup_psci_ops(uintptr_t sec_entrypoint,
315f91c3cb1SSiva Durga Prasad Paladugu 			const struct plat_psci_ops **psci_ops)
316f91c3cb1SSiva Durga Prasad Paladugu {
317f91c3cb1SSiva Durga Prasad Paladugu 	versal_sec_entry = sec_entrypoint;
318f91c3cb1SSiva Durga Prasad Paladugu 
319f91c3cb1SSiva Durga Prasad Paladugu 	*psci_ops = &versal_nopmc_psci_ops;
320f91c3cb1SSiva Durga Prasad Paladugu 
321f91c3cb1SSiva Durga Prasad Paladugu 	return 0;
322f91c3cb1SSiva Durga Prasad Paladugu }
323