linux/drivers/firmware/qcom_scm.h
Guru Das Srinagesh 6bf3259922 firmware: qcom: scm: Add wait-queue handling logic
When the firmware (FW) supports multiple requests per VM, multiple requests
from the same/different VM can reach the firmware at the same time. Since
the firmware currently being used has limited resources, it guards them
with a resource lock and puts requests on a wait-queue internally and
signals to HLOS that it is doing so. It does this by returning a new return
value in addition to success or error: SCM_WAITQ_SLEEP. A sleeping SCM call
can be woken up by an interrupt that the FW raises.

  1) SCM_WAITQ_SLEEP:

  	When an SCM call receives this return value instead of success
  	or error, FW has placed this call on a wait-queue and has signalled
	HLOS to put it to non-interruptible sleep.

	Along with this return value, FW also passes to HLOS `wq_ctx` -
	a unique number (UID) identifying the wait-queue that it has put
	the call on, internally. This is to help HLOS with its own
	bookkeeping to wake this sleeping call later.

	Additionally, FW also passes to HLOS `smc_call_ctx` - a UID
	identifying the SCM call thus being put to sleep. This is also
	for HLOS' bookkeeping to wake this call up later.

	These two additional values are passed via the a1 and a2
	registers.

	N.B.: The "ctx" in the above UID names = "context".

The handshake mechanism that HLOS uses to talk to FW about wait-queue
operations involves two new SMC calls.

  1) get_wq_ctx():

    	Arguments: 	None
    	Returns:	wq_ctx, flags, more_pending

    	Get the wait-queue context, and wake up either one or all of the
    	sleeping SCM calls associated with that wait-queue.

    	Additionally, repeat this if there are more wait-queues that are
    	ready to have their requests woken up (`more_pending`).

  2) wq_resume(smc_call_ctx):

  	Arguments:	smc_call_ctx

  	HLOS needs to issue this in response to receiving an
  	IRQ, passing to FW the same smc_call_ctx that FW
  	receives from HLOS via the get_wq_ctx() call.

(The mechanism to wake a SMC call back up is described in detail below)

 VM_1                     VM_2                            Firmware
   │                        │                                 │
   │                        │                                 │
   │                        │                                 │
   │                        │                                 │
   │      REQUEST_1         │                                 │
   ├────────────────────────┼─────────────────────────────────┤
   │                        │                                 │
   │                        │                              ┌──┼──┐
   │                        │                              │  │  │
   │                        │     REQUEST_2                │  │  │
   │                        ├──────────────────────────────┼──┤  │
   │                        │                              │  │  │Resource
   │                        │                              │  │  │is busy
   │                        │       {WQ_SLEEP}             │  │  │
   │                        │◄─────────────────────────────┼──┤  │
   │                        │  wq_ctx, smc_call_ctx        │  │  │
   │                        │                              └──┼──┘
   │   REQUEST_1 COMPLETE   │                                 │
   │◄───────────────────────┼─────────────────────────────────┤
   │                        │                                 │
   │                        │         IRQ                     │
   │                        │◄─-------------------------------│
   │                        │                                 │
   │                        │      get_wq_ctx()               │
   │                        ├────────────────────────────────►│
   │                        │                                 │
   │                        │                                 │
   │                        │◄────────────────────────────────┤
   │                        │   wq_ctx, flags, and            │
   │                        │        more_pending             │
   │                        │                                 │
   │                        │                                 │
   │                        │ wq_resume(smc_call_ctx)         │
   │                        ├────────────────────────────────►│
   │                        │                                 │
   │                        │                                 │
   │                        │      REQUEST_2 COMPLETE         │
   │                        │◄────────────────────────────────┤
   │                        │                                 │
   │                        │                                 │

With the exception of get_wq_ctx(), the other SMC call wq_resume() can
return WQ_SLEEP (these nested rounds of WQ_SLEEP are not shown in the
above diagram for the sake of simplicity). Therefore, introduce a new
do-while loop to handle multiple WQ_SLEEP return values for the same
parent SCM call.

Request Completion in the above diagram refers to either a success
return value (zero) or error (and not SMC_WAITQ_SLEEP)

Also add the interrupt handler that wakes up a sleeping SCM call.

Signed-off-by: Guru Das Srinagesh <quic_gurus@quicinc.com>
Co-developed-by: Sibi Sankar <quic_sibis@quicinc.com>
Signed-off-by: Sibi Sankar <quic_sibis@quicinc.com>
Reviewed-by: Guru Das Srinagesh <quic_gurus@quicinc.com>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230113161114.22607-3-quic_sibis@quicinc.com
2023-01-18 21:14:40 -06:00

168 lines
4.6 KiB
C

/* SPDX-License-Identifier: GPL-2.0-only */
/* Copyright (c) 2010-2015,2019 The Linux Foundation. All rights reserved.
*/
#ifndef __QCOM_SCM_INT_H
#define __QCOM_SCM_INT_H
enum qcom_scm_convention {
SMC_CONVENTION_UNKNOWN,
SMC_CONVENTION_LEGACY,
SMC_CONVENTION_ARM_32,
SMC_CONVENTION_ARM_64,
};
extern enum qcom_scm_convention qcom_scm_convention;
#define MAX_QCOM_SCM_ARGS 10
#define MAX_QCOM_SCM_RETS 3
enum qcom_scm_arg_types {
QCOM_SCM_VAL,
QCOM_SCM_RO,
QCOM_SCM_RW,
QCOM_SCM_BUFVAL,
};
#define QCOM_SCM_ARGS_IMPL(num, a, b, c, d, e, f, g, h, i, j, ...) (\
(((a) & 0x3) << 4) | \
(((b) & 0x3) << 6) | \
(((c) & 0x3) << 8) | \
(((d) & 0x3) << 10) | \
(((e) & 0x3) << 12) | \
(((f) & 0x3) << 14) | \
(((g) & 0x3) << 16) | \
(((h) & 0x3) << 18) | \
(((i) & 0x3) << 20) | \
(((j) & 0x3) << 22) | \
((num) & 0xf))
#define QCOM_SCM_ARGS(...) QCOM_SCM_ARGS_IMPL(__VA_ARGS__, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0)
/**
* struct qcom_scm_desc
* @arginfo: Metadata describing the arguments in args[]
* @args: The array of arguments for the secure syscall
*/
struct qcom_scm_desc {
u32 svc;
u32 cmd;
u32 arginfo;
u64 args[MAX_QCOM_SCM_ARGS];
u32 owner;
};
/**
* struct qcom_scm_res
* @result: The values returned by the secure syscall
*/
struct qcom_scm_res {
u64 result[MAX_QCOM_SCM_RETS];
};
int qcom_scm_wait_for_wq_completion(u32 wq_ctx);
int scm_get_wq_ctx(u32 *wq_ctx, u32 *flags, u32 *more_pending);
#define SCM_SMC_FNID(s, c) ((((s) & 0xFF) << 8) | ((c) & 0xFF))
extern int __scm_smc_call(struct device *dev, const struct qcom_scm_desc *desc,
enum qcom_scm_convention qcom_convention,
struct qcom_scm_res *res, bool atomic);
#define scm_smc_call(dev, desc, res, atomic) \
__scm_smc_call((dev), (desc), qcom_scm_convention, (res), (atomic))
#define SCM_LEGACY_FNID(s, c) (((s) << 10) | ((c) & 0x3ff))
extern int scm_legacy_call_atomic(struct device *dev,
const struct qcom_scm_desc *desc,
struct qcom_scm_res *res);
extern int scm_legacy_call(struct device *dev, const struct qcom_scm_desc *desc,
struct qcom_scm_res *res);
#define QCOM_SCM_SVC_BOOT 0x01
#define QCOM_SCM_BOOT_SET_ADDR 0x01
#define QCOM_SCM_BOOT_TERMINATE_PC 0x02
#define QCOM_SCM_BOOT_SET_DLOAD_MODE 0x10
#define QCOM_SCM_BOOT_SET_ADDR_MC 0x11
#define QCOM_SCM_BOOT_SET_REMOTE_STATE 0x0a
#define QCOM_SCM_FLUSH_FLAG_MASK 0x3
#define QCOM_SCM_BOOT_MAX_CPUS 4
#define QCOM_SCM_BOOT_MC_FLAG_AARCH64 BIT(0)
#define QCOM_SCM_BOOT_MC_FLAG_COLDBOOT BIT(1)
#define QCOM_SCM_BOOT_MC_FLAG_WARMBOOT BIT(2)
#define QCOM_SCM_SVC_PIL 0x02
#define QCOM_SCM_PIL_PAS_INIT_IMAGE 0x01
#define QCOM_SCM_PIL_PAS_MEM_SETUP 0x02
#define QCOM_SCM_PIL_PAS_AUTH_AND_RESET 0x05
#define QCOM_SCM_PIL_PAS_SHUTDOWN 0x06
#define QCOM_SCM_PIL_PAS_IS_SUPPORTED 0x07
#define QCOM_SCM_PIL_PAS_MSS_RESET 0x0a
#define QCOM_SCM_SVC_IO 0x05
#define QCOM_SCM_IO_READ 0x01
#define QCOM_SCM_IO_WRITE 0x02
#define QCOM_SCM_SVC_INFO 0x06
#define QCOM_SCM_INFO_IS_CALL_AVAIL 0x01
#define QCOM_SCM_SVC_MP 0x0c
#define QCOM_SCM_MP_RESTORE_SEC_CFG 0x02
#define QCOM_SCM_MP_IOMMU_SECURE_PTBL_SIZE 0x03
#define QCOM_SCM_MP_IOMMU_SECURE_PTBL_INIT 0x04
#define QCOM_SCM_MP_IOMMU_SET_CP_POOL_SIZE 0x05
#define QCOM_SCM_MP_VIDEO_VAR 0x08
#define QCOM_SCM_MP_ASSIGN 0x16
#define QCOM_SCM_SVC_OCMEM 0x0f
#define QCOM_SCM_OCMEM_LOCK_CMD 0x01
#define QCOM_SCM_OCMEM_UNLOCK_CMD 0x02
#define QCOM_SCM_SVC_ES 0x10 /* Enterprise Security */
#define QCOM_SCM_ES_INVALIDATE_ICE_KEY 0x03
#define QCOM_SCM_ES_CONFIG_SET_ICE_KEY 0x04
#define QCOM_SCM_SVC_HDCP 0x11
#define QCOM_SCM_HDCP_INVOKE 0x01
#define QCOM_SCM_SVC_LMH 0x13
#define QCOM_SCM_LMH_LIMIT_PROFILE_CHANGE 0x01
#define QCOM_SCM_LMH_LIMIT_DCVSH 0x10
#define QCOM_SCM_SVC_SMMU_PROGRAM 0x15
#define QCOM_SCM_SMMU_PT_FORMAT 0x01
#define QCOM_SCM_SMMU_CONFIG_ERRATA1 0x03
#define QCOM_SCM_SMMU_CONFIG_ERRATA1_CLIENT_ALL 0x02
#define QCOM_SCM_SVC_WAITQ 0x24
#define QCOM_SCM_WAITQ_RESUME 0x02
#define QCOM_SCM_WAITQ_GET_WQ_CTX 0x03
/* common error codes */
#define QCOM_SCM_V2_EBUSY -12
#define QCOM_SCM_ENOMEM -5
#define QCOM_SCM_EOPNOTSUPP -4
#define QCOM_SCM_EINVAL_ADDR -3
#define QCOM_SCM_EINVAL_ARG -2
#define QCOM_SCM_ERROR -1
#define QCOM_SCM_INTERRUPTED 1
#define QCOM_SCM_WAITQ_SLEEP 2
static inline int qcom_scm_remap_error(int err)
{
switch (err) {
case QCOM_SCM_ERROR:
return -EIO;
case QCOM_SCM_EINVAL_ADDR:
case QCOM_SCM_EINVAL_ARG:
return -EINVAL;
case QCOM_SCM_EOPNOTSUPP:
return -EOPNOTSUPP;
case QCOM_SCM_ENOMEM:
return -ENOMEM;
case QCOM_SCM_V2_EBUSY:
return -EBUSY;
}
return -EINVAL;
}
#endif