On 19/08/16 18:32, Thierry Reding wrote:
> From: Thierry Reding <treding@xxxxxxxxxx>
>
> The Inter-VM communication (IVC) is a communication protocol which is
> designed for interprocessor communication (IPC) or the communication
> between the hypervisor and the virtual machine with a guest OS.
>
> Message channels are used to communicate between processors. They are
> backed by DRAM or SRAM, so care must be taken to maintain coherence of
> data.
>
> The IVC library maintains memory-based descriptors for the transmission
> and reception channels as well as the data coherence of the counter and
> payload. Clients, such as the driver for the BPMP firmware, can use the
> library to exchange messages with remote processors.
>
> Based on work by Peter Newman <pnewman@xxxxxxxxxx> and Joseph Lo
> <josephl@xxxxxxxxxx>.
>
> Signed-off-by: Thierry Reding <treding@xxxxxxxxxx>
> ---
> Changes in v3:
> - use a more object oriented design
>
> drivers/firmware/Kconfig | 1 +
> drivers/firmware/Makefile | 1 +
> drivers/firmware/tegra/Kconfig | 13 +
> drivers/firmware/tegra/Makefile | 1 +
> drivers/firmware/tegra/ivc.c | 683 ++++++++++++++++++++++++++++++++++++++++
> include/soc/tegra/ivc.h | 109 +++++++
> 6 files changed, 808 insertions(+)
> create mode 100644 drivers/firmware/tegra/Kconfig
> create mode 100644 drivers/firmware/tegra/Makefile
> create mode 100644 drivers/firmware/tegra/ivc.c
> create mode 100644 include/soc/tegra/ivc.h
[snip]
> +static int check_ivc_params(unsigned long base1, unsigned long base2,
> + unsigned int num_frames, size_t frame_size)
> +{
> + BUG_ON(offsetof(struct tegra_ivc_header, tx.count) & (TEGRA_IVC_ALIGN - 1));
> + BUG_ON(offsetof(struct tegra_ivc_header, rx.count) & (TEGRA_IVC_ALIGN - 1));
> + BUG_ON(sizeof(struct tegra_ivc_header) & (TEGRA_IVC_ALIGN - 1));
> +
> + if ((uint64_t)num_frames * (uint64_t)frame_size >= 0x100000000) {
> + pr_err("num_frames * frame_size overflows\n");
> + return -EINVAL;
> + }
This generates the following sparse warning ...
drivers/firmware/tegra/ivc.c:574:60: warning: constant 0x100000000 is so
big it is long
I think we need to append a UL.
> +
> + /*
> + * The headers must at least be aligned enough for counters
> + * to be accessed atomically.
> + */
> + if (base1 & (TEGRA_IVC_ALIGN - 1)) {
> + pr_err("IVC channel start not aligned: %lx\n", base1);
> + return -EINVAL;
> + }
> +
> + if (base2 & (TEGRA_IVC_ALIGN - 1)) {
> + pr_err("IVC channel start not aligned: %lx\n", base2);
> + return -EINVAL;
> + }
> +
> + if (frame_size & (TEGRA_IVC_ALIGN - 1)) {
> + pr_err("frame size not adequately aligned: %zu\n", frame_size);
> + return -EINVAL;
> + }
> +
> + if (base1 < base2) {
> + if (base1 + frame_size * num_frames > base2) {
> + pr_err("queue regions overlap: %lx + %zx, %zx\n",
> + base1, frame_size, frame_size * num_frames);
> + return -EINVAL;
> + }
> + } else {
> + if (base2 + frame_size * num_frames > base1) {
> + pr_err("queue regions overlap: %lx + %zx, %zx\n",
> + base2, frame_size, frame_size * num_frames);
> + return -EINVAL;
> + }
> + }
> +
> + return 0;
> +}
> +
> +int tegra_ivc_init(struct tegra_ivc *ivc, struct device *peer,
> + void __iomem *rx_virt, dma_addr_t rx_phys,
> + void __iomem *tx_virt, dma_addr_t tx_phys,
> + unsigned int num_frames, size_t frame_size,
> + void (*notify)(struct tegra_ivc *ivc, void *data),
> + void *data)
> +{
> + size_t queue_size;
> + int err;
> +
> + err = check_ivc_params((unsigned long)rx_virt, (unsigned long)tx_virt,
> + num_frames, frame_size);
> + if (err < 0)
> + return err;
> +
> + BUG_ON(!ivc);
> + BUG_ON(!notify);
> +
> + queue_size = tegra_ivc_total_queue_size(num_frames * frame_size);
> +
> + /*
> + * All sizes that can be returned by communication functions should
> + * fit in an int.
> + */
> + if (frame_size > INT_MAX)
> + return -E2BIG;
> +
> + ivc->rx.channel = (struct tegra_ivc_header *)rx_virt;
> + ivc->tx.channel = (struct tegra_ivc_header *)tx_virt;
And these generate the sparse warnings ...
drivers/firmware/tegra/ivc.c:642:28: warning: cast removes address space
of expression
drivers/firmware/tegra/ivc.c:643:28: warning: cast removes address space
of expression
Cheers
Jon
--
nvpublic
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