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Kernel: Refactor Aarch64 MailBox class

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The goal was to reduce common setup of messages. Changes:
* MailBox turned into singleton to follow existing patterns
* Removed device specific messages from MailBox requiring
  clients to know the details instead
* Created base Message class which clients should deriver from

It really simplify the usage for more complicated message queues
like framebuffer setup - see followup commits.
This commit is contained in:
Marcin Undak 2021-10-16 18:52:31 -04:00 • committed by Andreas Kling
parent 82a73b8499
commit 3cc5752a69
7 changed files with 257 additions and 68 deletions
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78
Kernel/Prekernel/Arch/aarch64/Mailbox.cpp
View file

@ -33,6 +33,30 @@ constexpr u32 MBOX_EMPTY = 0x4000'0000;
constexpr int ARM_TO_VIDEOCORE_CHANNEL = 8;
Mailbox::Message::Message(u32 tag, u32 arguments_size)
{
m_tag = tag;
m_arguments_size = arguments_size;
m_command_tag = MBOX_REQUEST;
}
Mailbox::MessageHeader::MessageHeader()
{
m_message_queue_size = 0;
m_command_tag = MBOX_REQUEST;
}
bool Mailbox::MessageHeader::success() const
{
return m_command_tag == MBOX_RESPONSE_SUCCESS;
}
Mailbox& Mailbox::the()
{
static Mailbox instance;
return instance;
}
static void wait_until_we_can_write(MMIO& mmio)
{
// Since nothing else writes to the mailbox, this wait is mostly cargo-culted.
@ -47,8 +71,14 @@ static void wait_for_reply(MMIO& mmio)
;
}
bool Mailbox::call(u8 channel, u32 volatile* __attribute__((aligned(16))) message)
bool Mailbox::send_queue(void* queue, u32 queue_size) const
{
// According to Raspberry Pi specs this is the only channel implemented.
const u32 channel = ARM_TO_VIDEOCORE_CHANNEL;
auto message_header = reinterpret_cast<MessageHeader*>(queue);
message_header->set_queue_size(queue_size);
auto& mmio = MMIO::the();
// The mailbox interface has a FIFO for message deliverly in both directions.
@ -59,7 +89,7 @@ bool Mailbox::call(u8 channel, u32 volatile* __attribute__((aligned(16))) messag
wait_until_we_can_write(mmio);
// The mailbox message is 32-bit based, so this assumes that message is in the first 4 GiB.
u32 request = static_cast<u32>(reinterpret_cast<FlatPtr>(message) & ~0xF) | (channel & 0xF);
u32 request = static_cast<u32>(reinterpret_cast<FlatPtr>(queue) & ~0xF) | (channel & 0xF);
mmio.write(MBOX_WRITE_DATA, request);
for (;;) {
@ -68,52 +98,10 @@ bool Mailbox::call(u8 channel, u32 volatile* __attribute__((aligned(16))) messag
u32 response = mmio.read(MBOX_READ_DATA);
// We keep at most one message in flight and do synchronous communication, so response will always be == request for us.
if (response == request)
return message[1] == MBOX_RESPONSE_SUCCESS;
return message_header->success();
}
return true;
}
constexpr u32 MBOX_TAG_GET_FIRMWARE_VERSION = 0x0000'0001;
constexpr u32 MBOX_TAG_SET_CLOCK_RATE = 0x0003'8002;
u32 Mailbox::query_firmware_version()
{
// See https://github.com/raspberrypi/firmware/wiki/Mailbox-property-interface for data format.
u32 __attribute__((aligned(16))) message[7];
message[0] = sizeof(message);
message[1] = MBOX_REQUEST;
message[2] = MBOX_TAG_GET_FIRMWARE_VERSION;
message[3] = 0; // Tag data size. MBOX_TAG_GET_FIRMWARE_VERSION needs no arguments.
message[4] = MBOX_REQUEST;
message[5] = 0; // Trailing zero for request, room for data in response.
message[6] = 0; // Room for trailing zero in response.
if (call(ARM_TO_VIDEOCORE_CHANNEL, message) && message[2] == MBOX_TAG_GET_FIRMWARE_VERSION)
return message[5];
return 0xffff'ffff;
}
u32 Mailbox::set_clock_rate(ClockID clock_id, u32 rate_hz, bool skip_setting_turbo)
{
u32 __attribute__((aligned(16))) message[9];
message[0] = sizeof(message);
message[1] = MBOX_REQUEST;
message[2] = MBOX_TAG_SET_CLOCK_RATE;
message[3] = 12; // Tag data size.
message[4] = MBOX_REQUEST;
message[5] = static_cast<u32>(clock_id);
message[6] = rate_hz;
message[7] = skip_setting_turbo ? 1 : 0;
message[8] = 0;
call(ARM_TO_VIDEOCORE_CHANNEL, message);
return message[6];
}
}