diff options
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/scif.h | 234 |
1 files changed, 224 insertions, 10 deletions
diff --git a/include/linux/scif.h b/include/linux/scif.h index fd62c051b166..49a35d6edc94 100644 --- a/include/linux/scif.h +++ b/include/linux/scif.h @@ -93,6 +93,27 @@ enum { #define SCIF_PORT_RSVD 1088 typedef struct scif_endpt *scif_epd_t; +typedef struct scif_pinned_pages *scif_pinned_pages_t; + +/** + * struct scif_range - SCIF registered range used in kernel mode + * @cookie: cookie used internally by SCIF + * @nr_pages: number of pages of PAGE_SIZE + * @prot_flags: R/W protection + * @phys_addr: Array of bus addresses + * @va: Array of kernel virtual addresses backed by the pages in the phys_addr + * array. The va is populated only when called on the host for a remote + * SCIF connection on MIC. This is required to support the use case of DMA + * between MIC and another device which is not a SCIF node e.g., an IB or + * ethernet NIC. + */ +struct scif_range { + void *cookie; + int nr_pages; + int prot_flags; + dma_addr_t *phys_addr; + void __iomem **va; +}; /** * struct scif_pollepd - SCIF endpoint to be monitored via scif_poll @@ -389,7 +410,6 @@ int scif_close(scif_epd_t epd); * Errors: * EBADF, ENOTTY - epd is not a valid endpoint descriptor * ECONNRESET - Connection reset by peer - * EFAULT - An invalid address was specified for a parameter * EINVAL - flags is invalid, or len is negative * ENODEV - The remote node is lost or existed, but is not currently in the * network since it may have crashed @@ -442,7 +462,6 @@ int scif_send(scif_epd_t epd, void *msg, int len, int flags); * EAGAIN - The destination node is returning from a low power state * EBADF, ENOTTY - epd is not a valid endpoint descriptor * ECONNRESET - Connection reset by peer - * EFAULT - An invalid address was specified for a parameter * EINVAL - flags is invalid, or len is negative * ENODEV - The remote node is lost or existed, but is not currently in the * network since it may have crashed @@ -505,9 +524,6 @@ int scif_recv(scif_epd_t epd, void *msg, int len, int flags); * SCIF_PROT_READ - allow read operations from the window * SCIF_PROT_WRITE - allow write operations to the window * - * The map_flags argument can be set to SCIF_MAP_FIXED which interprets a - * fixed offset. - * * Return: * Upon successful completion, scif_register() returns the offset at which the * mapping was placed (po); otherwise in user mode SCIF_REGISTER_FAILED (that @@ -520,7 +536,6 @@ int scif_recv(scif_epd_t epd, void *msg, int len, int flags); * EAGAIN - The mapping could not be performed due to lack of resources * EBADF, ENOTTY - epd is not a valid endpoint descriptor * ECONNRESET - Connection reset by peer - * EFAULT - Addresses in the range [addr, addr + len - 1] are invalid * EINVAL - map_flags is invalid, or prot_flags is invalid, or SCIF_MAP_FIXED is * set in flags, and offset is not a multiple of the page size, or addr is not a * multiple of the page size, or len is not a multiple of the page size, or is @@ -803,7 +818,6 @@ int scif_writeto(scif_epd_t epd, off_t loffset, size_t len, off_t * EACCESS - Attempt to write to a read-only range * EBADF, ENOTTY - epd is not a valid endpoint descriptor * ECONNRESET - Connection reset by peer - * EFAULT - Addresses in the range [addr, addr + len - 1] are invalid * EINVAL - rma_flags is invalid * ENODEV - The remote node is lost or existed, but is not currently in the * network since it may have crashed @@ -884,7 +898,6 @@ int scif_vreadfrom(scif_epd_t epd, void *addr, size_t len, off_t roffset, * EACCESS - Attempt to write to a read-only range * EBADF, ENOTTY - epd is not a valid endpoint descriptor * ECONNRESET - Connection reset by peer - * EFAULT - Addresses in the range [addr, addr + len - 1] are invalid * EINVAL - rma_flags is invalid * ENODEV - The remote node is lost or existed, but is not currently in the * network since it may have crashed @@ -1028,11 +1041,212 @@ int scif_fence_signal(scif_epd_t epd, off_t loff, u64 lval, off_t roff, * online nodes in the SCIF network including 'self'; otherwise in user mode * -1 is returned and errno is set to indicate the error; in kernel mode no * errors are returned. + */ +int scif_get_node_ids(u16 *nodes, int len, u16 *self); + +/** + * scif_pin_pages() - Pin a set of pages + * @addr: Virtual address of range to pin + * @len: Length of range to pin + * @prot_flags: Page protection flags + * @map_flags: Page classification flags + * @pinned_pages: Handle to pinned pages + * + * scif_pin_pages() pins (locks in physical memory) the physical pages which + * back the range of virtual address pages starting at addr and continuing for + * len bytes. addr and len are constrained to be multiples of the page size. A + * successful scif_pin_pages() call returns a handle to pinned_pages which may + * be used in subsequent calls to scif_register_pinned_pages(). + * + * The pages will remain pinned as long as there is a reference against the + * scif_pinned_pages_t value returned by scif_pin_pages() and until + * scif_unpin_pages() is called, passing the scif_pinned_pages_t value. A + * reference is added to a scif_pinned_pages_t value each time a window is + * created by calling scif_register_pinned_pages() and passing the + * scif_pinned_pages_t value. A reference is removed from a + * scif_pinned_pages_t value each time such a window is deleted. + * + * Subsequent operations which change the memory pages to which virtual + * addresses are mapped (such as mmap(), munmap()) have no effect on the + * scif_pinned_pages_t value or windows created against it. + * + * If the process will fork(), it is recommended that the registered + * virtual address range be marked with MADV_DONTFORK. Doing so will prevent + * problems due to copy-on-write semantics. + * + * The prot_flags argument is formed by OR'ing together one or more of the + * following values. + * SCIF_PROT_READ - allow read operations against the pages + * SCIF_PROT_WRITE - allow write operations against the pages + * The map_flags argument can be set as SCIF_MAP_KERNEL to interpret addr as a + * kernel space address. By default, addr is interpreted as a user space + * address. + * + * Return: + * Upon successful completion, scif_pin_pages() returns 0; otherwise the + * negative of one of the following errors is returned. * * Errors: - * EFAULT - Bad address + * EINVAL - prot_flags is invalid, map_flags is invalid, or offset is negative + * ENOMEM - Not enough space */ -int scif_get_node_ids(u16 *nodes, int len, u16 *self); +int scif_pin_pages(void *addr, size_t len, int prot_flags, int map_flags, + scif_pinned_pages_t *pinned_pages); + +/** + * scif_unpin_pages() - Unpin a set of pages + * @pinned_pages: Handle to pinned pages to be unpinned + * + * scif_unpin_pages() prevents scif_register_pinned_pages() from registering new + * windows against pinned_pages. The physical pages represented by pinned_pages + * will remain pinned until all windows previously registered against + * pinned_pages are deleted (the window is scif_unregister()'d and all + * references to the window are removed (see scif_unregister()). + * + * pinned_pages must have been obtain from a previous call to scif_pin_pages(). + * After calling scif_unpin_pages(), it is an error to pass pinned_pages to + * scif_register_pinned_pages(). + * + * Return: + * Upon successful completion, scif_unpin_pages() returns 0; otherwise the + * negative of one of the following errors is returned. + * + * Errors: + * EINVAL - pinned_pages is not valid + */ +int scif_unpin_pages(scif_pinned_pages_t pinned_pages); + +/** + * scif_register_pinned_pages() - Mark a memory region for remote access. + * @epd: endpoint descriptor + * @pinned_pages: Handle to pinned pages + * @offset: Registered address space offset + * @map_flags: Flags which control where pages are mapped + * + * The scif_register_pinned_pages() function opens a window, a range of whole + * pages of the registered address space of the endpoint epd, starting at + * offset po. The value of po, further described below, is a function of the + * parameters offset and pinned_pages, and the value of map_flags. Each page of + * the window represents a corresponding physical memory page of the range + * represented by pinned_pages; the length of the window is the same as the + * length of range represented by pinned_pages. A successful + * scif_register_pinned_pages() call returns po as the return value. + * + * When SCIF_MAP_FIXED is set in the map_flags argument, po will be offset + * exactly, and offset is constrained to be a multiple of the page size. The + * mapping established by scif_register_pinned_pages() will not replace any + * existing registration; an error is returned if any page of the new window + * would intersect an existing window. + * + * When SCIF_MAP_FIXED is not set, the implementation uses offset in an + * implementation-defined manner to arrive at po. The po so chosen will be an + * area of the registered address space that the implementation deems suitable + * for a mapping of the required size. An offset value of 0 is interpreted as + * granting the implementation complete freedom in selecting po, subject to + * constraints described below. A non-zero value of offset is taken to be a + * suggestion of an offset near which the mapping should be placed. When the + * implementation selects a value for po, it does not replace any extant + * window. In all cases, po will be a multiple of the page size. + * + * The physical pages which are so represented by a window are available for + * access in calls to scif_get_pages(), scif_readfrom(), scif_writeto(), + * scif_vreadfrom(), and scif_vwriteto(). While a window is registered, the + * physical pages represented by the window will not be reused by the memory + * subsystem for any other purpose. Note that the same physical page may be + * represented by multiple windows. + * + * Windows created by scif_register_pinned_pages() are unregistered by + * scif_unregister(). + * + * The map_flags argument can be set to SCIF_MAP_FIXED which interprets a + * fixed offset. + * + * Return: + * Upon successful completion, scif_register_pinned_pages() returns the offset + * at which the mapping was placed (po); otherwise the negative of one of the + * following errors is returned. + * + * Errors: + * EADDRINUSE - SCIF_MAP_FIXED is set in map_flags and pages in the new window + * would intersect an existing window + * EAGAIN - The mapping could not be performed due to lack of resources + * ECONNRESET - Connection reset by peer + * EINVAL - map_flags is invalid, or SCIF_MAP_FIXED is set in map_flags, and + * offset is not a multiple of the page size, or offset is negative + * ENODEV - The remote node is lost or existed, but is not currently in the + * network since it may have crashed + * ENOMEM - Not enough space + * ENOTCONN - The endpoint is not connected + */ +off_t scif_register_pinned_pages(scif_epd_t epd, + scif_pinned_pages_t pinned_pages, + off_t offset, int map_flags); + +/** + * scif_get_pages() - Add references to remote registered pages + * @epd: endpoint descriptor + * @offset: remote registered offset + * @len: length of range of pages + * @pages: returned scif_range structure + * + * scif_get_pages() returns the addresses of the physical pages represented by + * those pages of the registered address space of the peer of epd, starting at + * offset and continuing for len bytes. offset and len are constrained to be + * multiples of the page size. + * + * All of the pages in the specified range [offset, offset + len - 1] must be + * within a single window of the registered address space of the peer of epd. + * + * The addresses are returned as a virtually contiguous array pointed to by the + * phys_addr component of the scif_range structure whose address is returned in + * pages. The nr_pages component of scif_range is the length of the array. The + * prot_flags component of scif_range holds the protection flag value passed + * when the pages were registered. + * + * Each physical page whose address is returned by scif_get_pages() remains + * available and will not be released for reuse until the scif_range structure + * is returned in a call to scif_put_pages(). The scif_range structure returned + * by scif_get_pages() must be unmodified. + * + * It is an error to call scif_close() on an endpoint on which a scif_range + * structure of that endpoint has not been returned to scif_put_pages(). + * + * Return: + * Upon successful completion, scif_get_pages() returns 0; otherwise the + * negative of one of the following errors is returned. + * Errors: + * ECONNRESET - Connection reset by peer. + * EINVAL - offset is not a multiple of the page size, or offset is negative, or + * len is not a multiple of the page size + * ENODEV - The remote node is lost or existed, but is not currently in the + * network since it may have crashed + * ENOTCONN - The endpoint is not connected + * ENXIO - Offsets in the range [offset, offset + len - 1] are invalid + * for the registered address space of the peer epd + */ +int scif_get_pages(scif_epd_t epd, off_t offset, size_t len, + struct scif_range **pages); + +/** + * scif_put_pages() - Remove references from remote registered pages + * @pages: pages to be returned + * + * scif_put_pages() releases a scif_range structure previously obtained by + * calling scif_get_pages(). The physical pages represented by pages may + * be reused when the window which represented those pages is unregistered. + * Therefore, those pages must not be accessed after calling scif_put_pages(). + * + * Return: + * Upon successful completion, scif_put_pages() returns 0; otherwise the + * negative of one of the following errors is returned. + * Errors: + * EINVAL - pages does not point to a valid scif_range structure, or + * the scif_range structure pointed to by pages was already returned + * ENODEV - The remote node is lost or existed, but is not currently in the + * network since it may have crashed + * ENOTCONN - The endpoint is not connected + */ +int scif_put_pages(struct scif_range *pages); /** * scif_poll() - Wait for some event on an endpoint |