xemu/hw/usb/hcd-xhci.h
Eric Blake f9919116b8 osdep: Make MIN/MAX evaluate arguments only once
I'm not aware of any immediate bugs in qemu where a second runtime
evaluation of the arguments to MIN() or MAX() causes a problem, but
proactively preventing such abuse is easier than falling prey to an
unintended case down the road.  At any rate, here's the conversation
that sparked the current patch:
https://lists.gnu.org/archive/html/qemu-devel/2018-12/msg05718.html

Update the MIN/MAX macros to only evaluate their argument once at
runtime; this uses typeof(1 ? (a) : (b)) to ensure that we are
promoting the temporaries to the same type as the final comparison (we
have to trigger type promotion, as typeof(bitfield) won't compile; and
we can't use typeof((a) + (b)) or even typeof((a) + 0), as some of our
uses of MAX are on void* pointers where such addition is undefined).

However, we are unable to work around gcc refusing to compile ({}) in
a constant context (such as the array length of a static variable),
even when only used in the dead branch of a __builtin_choose_expr(),
so we have to provide a second macro pair MIN_CONST and MAX_CONST for
use when both arguments are known to be compile-time constants and
where the result must also be usable as a constant; this second form
evaluates arguments multiple times but that doesn't matter for
constants.  By using a void expression as the expansion if a
non-constant is presented to this second form, we can enlist the
compiler to ensure the double evaluation is not attempted on
non-constants.

Alas, as both macros now rely on compiler intrinsics, they are no
longer usable in preprocessor #if conditions; those will just have to
be open-coded or the logic rewritten into #define or runtime 'if'
conditions (but where the compiler dead-code-elimination will probably
still apply).

I tested that both gcc 10.1.1 and clang 10.0.0 produce errors for all
forms of macro mis-use.  As the errors can sometimes be cryptic, I'm
demonstrating the gcc output:

Use of MIN when MIN_CONST is needed:

In file included from /home/eblake/qemu/qemu-img.c:25:
/home/eblake/qemu/include/qemu/osdep.h:249:5: error: braced-group within expression allowed only inside a function
  249 |     ({                                                  \
      |     ^
/home/eblake/qemu/qemu-img.c:92:12: note: in expansion of macro ‘MIN’
   92 | char array[MIN(1, 2)] = "";
      |            ^~~

Use of MIN_CONST when MIN is needed:

/home/eblake/qemu/qemu-img.c: In function ‘is_allocated_sectors’:
/home/eblake/qemu/qemu-img.c:1225:15: error: void value not ignored as it ought to be
 1225 |             i = MIN_CONST(i, n);
      |               ^

Use of MIN in the preprocessor:

In file included from /home/eblake/qemu/accel/tcg/translate-all.c:20:
/home/eblake/qemu/accel/tcg/translate-all.c: In function ‘page_check_range’:
/home/eblake/qemu/include/qemu/osdep.h:249:6: error: token "{" is not valid in preprocessor expressions
  249 |     ({                                                  \
      |      ^

Fix the resulting callsites that used #if or computed a compile-time
constant min or max to use the new macros.  cpu-defs.h is interesting,
as CPU_TLB_DYN_MAX_BITS is sometimes used as a constant and sometimes
dynamic.

It may be worth improving glib's MIN/MAX definitions to be saner, but
that is a task for another day.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20200625162602.700741-1-eblake@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-26 09:39:39 -04:00

233 lines
5.3 KiB
C

/*
* USB xHCI controller emulation
*
* Copyright (c) 2011 Securiforest
* Date: 2011-05-11 ; Author: Hector Martin <hector@marcansoft.com>
* Based on usb-ohci.c, emulates Renesas NEC USB 3.0
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/
#ifndef HW_USB_HCD_XHCI_H
#define HW_USB_HCD_XHCI_H
#define TYPE_XHCI "base-xhci"
#define TYPE_NEC_XHCI "nec-usb-xhci"
#define TYPE_QEMU_XHCI "qemu-xhci"
#define XHCI(obj) \
OBJECT_CHECK(XHCIState, (obj), TYPE_XHCI)
#define MAXPORTS_2 15
#define MAXPORTS_3 15
#define MAXPORTS (MAXPORTS_2 + MAXPORTS_3)
#define MAXSLOTS 64
#define MAXINTRS 16
/* Very pessimistic, let's hope it's enough for all cases */
#define EV_QUEUE (((3 * 24) + 16) * MAXSLOTS)
typedef struct XHCIState XHCIState;
typedef struct XHCIStreamContext XHCIStreamContext;
typedef struct XHCIEPContext XHCIEPContext;
enum xhci_flags {
XHCI_FLAG_SS_FIRST = 1,
XHCI_FLAG_FORCE_PCIE_ENDCAP,
XHCI_FLAG_ENABLE_STREAMS,
};
typedef enum TRBType {
TRB_RESERVED = 0,
TR_NORMAL,
TR_SETUP,
TR_DATA,
TR_STATUS,
TR_ISOCH,
TR_LINK,
TR_EVDATA,
TR_NOOP,
CR_ENABLE_SLOT,
CR_DISABLE_SLOT,
CR_ADDRESS_DEVICE,
CR_CONFIGURE_ENDPOINT,
CR_EVALUATE_CONTEXT,
CR_RESET_ENDPOINT,
CR_STOP_ENDPOINT,
CR_SET_TR_DEQUEUE,
CR_RESET_DEVICE,
CR_FORCE_EVENT,
CR_NEGOTIATE_BW,
CR_SET_LATENCY_TOLERANCE,
CR_GET_PORT_BANDWIDTH,
CR_FORCE_HEADER,
CR_NOOP,
ER_TRANSFER = 32,
ER_COMMAND_COMPLETE,
ER_PORT_STATUS_CHANGE,
ER_BANDWIDTH_REQUEST,
ER_DOORBELL,
ER_HOST_CONTROLLER,
ER_DEVICE_NOTIFICATION,
ER_MFINDEX_WRAP,
/* vendor specific bits */
CR_VENDOR_NEC_FIRMWARE_REVISION = 49,
CR_VENDOR_NEC_CHALLENGE_RESPONSE = 50,
} TRBType;
typedef enum TRBCCode {
CC_INVALID = 0,
CC_SUCCESS,
CC_DATA_BUFFER_ERROR,
CC_BABBLE_DETECTED,
CC_USB_TRANSACTION_ERROR,
CC_TRB_ERROR,
CC_STALL_ERROR,
CC_RESOURCE_ERROR,
CC_BANDWIDTH_ERROR,
CC_NO_SLOTS_ERROR,
CC_INVALID_STREAM_TYPE_ERROR,
CC_SLOT_NOT_ENABLED_ERROR,
CC_EP_NOT_ENABLED_ERROR,
CC_SHORT_PACKET,
CC_RING_UNDERRUN,
CC_RING_OVERRUN,
CC_VF_ER_FULL,
CC_PARAMETER_ERROR,
CC_BANDWIDTH_OVERRUN,
CC_CONTEXT_STATE_ERROR,
CC_NO_PING_RESPONSE_ERROR,
CC_EVENT_RING_FULL_ERROR,
CC_INCOMPATIBLE_DEVICE_ERROR,
CC_MISSED_SERVICE_ERROR,
CC_COMMAND_RING_STOPPED,
CC_COMMAND_ABORTED,
CC_STOPPED,
CC_STOPPED_LENGTH_INVALID,
CC_MAX_EXIT_LATENCY_TOO_LARGE_ERROR = 29,
CC_ISOCH_BUFFER_OVERRUN = 31,
CC_EVENT_LOST_ERROR,
CC_UNDEFINED_ERROR,
CC_INVALID_STREAM_ID_ERROR,
CC_SECONDARY_BANDWIDTH_ERROR,
CC_SPLIT_TRANSACTION_ERROR
} TRBCCode;
typedef struct XHCIRing {
dma_addr_t dequeue;
bool ccs;
} XHCIRing;
typedef struct XHCIPort {
XHCIState *xhci;
uint32_t portsc;
uint32_t portnr;
USBPort *uport;
uint32_t speedmask;
char name[16];
MemoryRegion mem;
} XHCIPort;
typedef struct XHCISlot {
bool enabled;
bool addressed;
uint16_t intr;
dma_addr_t ctx;
USBPort *uport;
XHCIEPContext *eps[31];
} XHCISlot;
typedef struct XHCIEvent {
TRBType type;
TRBCCode ccode;
uint64_t ptr;
uint32_t length;
uint32_t flags;
uint8_t slotid;
uint8_t epid;
} XHCIEvent;
typedef struct XHCIInterrupter {
uint32_t iman;
uint32_t imod;
uint32_t erstsz;
uint32_t erstba_low;
uint32_t erstba_high;
uint32_t erdp_low;
uint32_t erdp_high;
bool msix_used, er_pcs;
dma_addr_t er_start;
uint32_t er_size;
unsigned int er_ep_idx;
/* kept for live migration compat only */
bool er_full_unused;
XHCIEvent ev_buffer[EV_QUEUE];
unsigned int ev_buffer_put;
unsigned int ev_buffer_get;
} XHCIInterrupter;
struct XHCIState {
/*< private >*/
PCIDevice parent_obj;
/*< public >*/
USBBus bus;
MemoryRegion mem;
MemoryRegion mem_cap;
MemoryRegion mem_oper;
MemoryRegion mem_runtime;
MemoryRegion mem_doorbell;
/* properties */
uint32_t numports_2;
uint32_t numports_3;
uint32_t numintrs;
uint32_t numslots;
uint32_t flags;
uint32_t max_pstreams_mask;
OnOffAuto msi;
OnOffAuto msix;
/* Operational Registers */
uint32_t usbcmd;
uint32_t usbsts;
uint32_t dnctrl;
uint32_t crcr_low;
uint32_t crcr_high;
uint32_t dcbaap_low;
uint32_t dcbaap_high;
uint32_t config;
USBPort uports[MAX_CONST(MAXPORTS_2, MAXPORTS_3)];
XHCIPort ports[MAXPORTS];
XHCISlot slots[MAXSLOTS];
uint32_t numports;
/* Runtime Registers */
int64_t mfindex_start;
QEMUTimer *mfwrap_timer;
XHCIInterrupter intr[MAXINTRS];
XHCIRing cmd_ring;
bool nec_quirks;
};
#endif