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 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html