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/*
* ARM TrustZone peripheral protection controller emulation
*
* Copyright (c) 2018 Linaro Limited
* Written by Peter Maydell
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 or
* (at your option) any later version.
*/
/* This is a model of the TrustZone peripheral protection controller (PPC).
* It is documented in the ARM CoreLink SIE-200 System IP for Embedded TRM
* (DDI 0571G):
* https://developer.arm.com/products/architecture/m-profile/docs/ddi0571/g
*
* The PPC sits in front of peripherals and allows secure software to
* configure it to either pass through or reject transactions.
* Rejected transactions may be configured to either be aborted, or to
* behave as RAZ/WI. An interrupt can be signalled for a rejected transaction.
*
* The PPC has no register interface -- it is configured purely by a
* collection of input signals from other hardware in the system. Typically
* they are either hardwired or exposed in an ad-hoc register interface by
* the SoC that uses the PPC.
*
* This QEMU model can be used to model either the AHB5 or APB4 TZ PPC,
* since the only difference between them is that the AHB version has a
* "default" port which has no security checks applied. In QEMU the default
* port can be emulated simply by wiring its downstream devices directly
* into the parent address space, since the PPC does not need to intercept
* transactions there.
*
* In the hardware, selection of which downstream port to use is done by
* the user's decode logic asserting one of the hsel[] signals. In QEMU,
* we provide 16 MMIO regions, one per port, and the user maps these into
* the desired addresses to implement the address decode.
*
* QEMU interface:
* + sysbus MMIO regions 0..15: MemoryRegions defining the upstream end
* of each of the 16 ports of the PPC. When a port is unused (i.e. no
* downstream MemoryRegion is connected to it) at the end of the 0..15
* range then no sysbus MMIO region is created for its upstream. When an
* unused port lies in the middle of the range with other used ports at
* higher port numbers, a dummy MMIO region is created to ensure that
* port N's upstream is always sysbus MMIO region N. Dummy regions should
* not be mapped, and will assert if any access is made to them.
* + Property "port[0..15]": MemoryRegion defining the downstream device(s)
* for each of the 16 ports of the PPC
* + Named GPIO inputs "cfg_nonsec[0..15]": set to 1 if the port should be
* accessible to NonSecure transactions
* + Named GPIO inputs "cfg_ap[0..15]": set to 1 if the port should be
* accessible to non-privileged transactions
* + Named GPIO input "cfg_sec_resp": set to 1 if a rejected transaction should
* result in a transaction error, or 0 for the transaction to RAZ/WI
* + Named GPIO input "irq_enable": set to 1 to enable interrupts
* + Named GPIO input "irq_clear": set to 1 to clear a pending interrupt
* + Named GPIO output "irq": set for a transaction-failed interrupt
* + Property "NONSEC_MASK": if a bit is set in this mask then accesses to
* the associated port do not have the TZ security check performed. (This
* corresponds to the hardware allowing this to be set as a Verilog
* parameter.)
*/
#ifndef TZ_PPC_H
#define TZ_PPC_H
#include "hw/sysbus.h"
#include "qom/object.h"
#define TYPE_TZ_PPC "tz-ppc"
OBJECT_DECLARE_SIMPLE_TYPE(TZPPC, TZ_PPC)
#define TZ_NUM_PORTS 16
typedef struct TZPPCPort {
TZPPC *ppc;
MemoryRegion upstream;
AddressSpace downstream_as;
MemoryRegion *downstream;
} TZPPCPort;
struct TZPPC {
/*< private >*/
SysBusDevice parent_obj;
/*< public >*/
/* State: these just track the values of our input signals */
bool cfg_nonsec[TZ_NUM_PORTS];
bool cfg_ap[TZ_NUM_PORTS];
bool cfg_sec_resp;
bool irq_enable;
bool irq_clear;
/* State: are we asserting irq ? */
bool irq_status;
qemu_irq irq;
/* Properties */
uint32_t nonsec_mask;
TZPPCPort port[TZ_NUM_PORTS];
};
#endif
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