diff options
Diffstat (limited to '')
| -rw-r--r-- | arch/powerpc/platforms/powernv/vas-window.c | 1279 |
1 files changed, 1279 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/powernv/vas-window.c b/arch/powerpc/platforms/powernv/vas-window.c new file mode 100644 index 000000000..e59e0e60e --- /dev/null +++ b/arch/powerpc/platforms/powernv/vas-window.c @@ -0,0 +1,1279 @@ +/* + * Copyright 2016-17 IBM Corp. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +#define pr_fmt(fmt) "vas: " fmt + +#include <linux/types.h> +#include <linux/mutex.h> +#include <linux/slab.h> +#include <linux/io.h> +#include <linux/log2.h> +#include <linux/rcupdate.h> +#include <linux/cred.h> +#include <asm/switch_to.h> +#include <asm/ppc-opcode.h> +#include "vas.h" +#include "copy-paste.h" + +#define CREATE_TRACE_POINTS +#include "vas-trace.h" + +/* + * Compute the paste address region for the window @window using the + * ->paste_base_addr and ->paste_win_id_shift we got from device tree. + */ +static void compute_paste_address(struct vas_window *window, u64 *addr, int *len) +{ + int winid; + u64 base, shift; + + base = window->vinst->paste_base_addr; + shift = window->vinst->paste_win_id_shift; + winid = window->winid; + + *addr = base + (winid << shift); + if (len) + *len = PAGE_SIZE; + + pr_debug("Txwin #%d: Paste addr 0x%llx\n", winid, *addr); +} + +u64 vas_win_paste_addr(struct vas_window *win) +{ + u64 addr; + + compute_paste_address(win, &addr, NULL); + + return addr; +} +EXPORT_SYMBOL(vas_win_paste_addr); + +static inline void get_hvwc_mmio_bar(struct vas_window *window, + u64 *start, int *len) +{ + u64 pbaddr; + + pbaddr = window->vinst->hvwc_bar_start; + *start = pbaddr + window->winid * VAS_HVWC_SIZE; + *len = VAS_HVWC_SIZE; +} + +static inline void get_uwc_mmio_bar(struct vas_window *window, + u64 *start, int *len) +{ + u64 pbaddr; + + pbaddr = window->vinst->uwc_bar_start; + *start = pbaddr + window->winid * VAS_UWC_SIZE; + *len = VAS_UWC_SIZE; +} + +/* + * Map the paste bus address of the given send window into kernel address + * space. Unlike MMIO regions (map_mmio_region() below), paste region must + * be mapped cache-able and is only applicable to send windows. + */ +static void *map_paste_region(struct vas_window *txwin) +{ + int len; + void *map; + char *name; + u64 start; + + name = kasprintf(GFP_KERNEL, "window-v%d-w%d", txwin->vinst->vas_id, + txwin->winid); + if (!name) + goto free_name; + + txwin->paste_addr_name = name; + compute_paste_address(txwin, &start, &len); + + if (!request_mem_region(start, len, name)) { + pr_devel("%s(): request_mem_region(0x%llx, %d) failed\n", + __func__, start, len); + goto free_name; + } + + map = ioremap_cache(start, len); + if (!map) { + pr_devel("%s(): ioremap_cache(0x%llx, %d) failed\n", __func__, + start, len); + goto free_name; + } + + pr_devel("Mapped paste addr 0x%llx to kaddr 0x%p\n", start, map); + return map; + +free_name: + kfree(name); + return ERR_PTR(-ENOMEM); +} + +static void *map_mmio_region(char *name, u64 start, int len) +{ + void *map; + + if (!request_mem_region(start, len, name)) { + pr_devel("%s(): request_mem_region(0x%llx, %d) failed\n", + __func__, start, len); + return NULL; + } + + map = ioremap(start, len); + if (!map) { + pr_devel("%s(): ioremap(0x%llx, %d) failed\n", __func__, start, + len); + return NULL; + } + + return map; +} + +static void unmap_region(void *addr, u64 start, int len) +{ + iounmap(addr); + release_mem_region((phys_addr_t)start, len); +} + +/* + * Unmap the paste address region for a window. + */ +static void unmap_paste_region(struct vas_window *window) +{ + int len; + u64 busaddr_start; + + if (window->paste_kaddr) { + compute_paste_address(window, &busaddr_start, &len); + unmap_region(window->paste_kaddr, busaddr_start, len); + window->paste_kaddr = NULL; + kfree(window->paste_addr_name); + window->paste_addr_name = NULL; + } +} + +/* + * Unmap the MMIO regions for a window. Hold the vas_mutex so we don't + * unmap when the window's debugfs dir is in use. This serializes close + * of a window even on another VAS instance but since its not a critical + * path, just minimize the time we hold the mutex for now. We can add + * a per-instance mutex later if necessary. + */ +static void unmap_winctx_mmio_bars(struct vas_window *window) +{ + int len; + void *uwc_map; + void *hvwc_map; + u64 busaddr_start; + + mutex_lock(&vas_mutex); + + hvwc_map = window->hvwc_map; + window->hvwc_map = NULL; + + uwc_map = window->uwc_map; + window->uwc_map = NULL; + + mutex_unlock(&vas_mutex); + + if (hvwc_map) { + get_hvwc_mmio_bar(window, &busaddr_start, &len); + unmap_region(hvwc_map, busaddr_start, len); + } + + if (uwc_map) { + get_uwc_mmio_bar(window, &busaddr_start, &len); + unmap_region(uwc_map, busaddr_start, len); + } +} + +/* + * Find the Hypervisor Window Context (HVWC) MMIO Base Address Region and the + * OS/User Window Context (UWC) MMIO Base Address Region for the given window. + * Map these bus addresses and save the mapped kernel addresses in @window. + */ +int map_winctx_mmio_bars(struct vas_window *window) +{ + int len; + u64 start; + + get_hvwc_mmio_bar(window, &start, &len); + window->hvwc_map = map_mmio_region("HVWCM_Window", start, len); + + get_uwc_mmio_bar(window, &start, &len); + window->uwc_map = map_mmio_region("UWCM_Window", start, len); + + if (!window->hvwc_map || !window->uwc_map) { + unmap_winctx_mmio_bars(window); + return -1; + } + + return 0; +} + +/* + * Reset all valid registers in the HV and OS/User Window Contexts for + * the window identified by @window. + * + * NOTE: We cannot really use a for loop to reset window context. Not all + * offsets in a window context are valid registers and the valid + * registers are not sequential. And, we can only write to offsets + * with valid registers. + */ +void reset_window_regs(struct vas_window *window) +{ + write_hvwc_reg(window, VREG(LPID), 0ULL); + write_hvwc_reg(window, VREG(PID), 0ULL); + write_hvwc_reg(window, VREG(XLATE_MSR), 0ULL); + write_hvwc_reg(window, VREG(XLATE_LPCR), 0ULL); + write_hvwc_reg(window, VREG(XLATE_CTL), 0ULL); + write_hvwc_reg(window, VREG(AMR), 0ULL); + write_hvwc_reg(window, VREG(SEIDR), 0ULL); + write_hvwc_reg(window, VREG(FAULT_TX_WIN), 0ULL); + write_hvwc_reg(window, VREG(OSU_INTR_SRC_RA), 0ULL); + write_hvwc_reg(window, VREG(HV_INTR_SRC_RA), 0ULL); + write_hvwc_reg(window, VREG(PSWID), 0ULL); + write_hvwc_reg(window, VREG(LFIFO_BAR), 0ULL); + write_hvwc_reg(window, VREG(LDATA_STAMP_CTL), 0ULL); + write_hvwc_reg(window, VREG(LDMA_CACHE_CTL), 0ULL); + write_hvwc_reg(window, VREG(LRFIFO_PUSH), 0ULL); + write_hvwc_reg(window, VREG(CURR_MSG_COUNT), 0ULL); + write_hvwc_reg(window, VREG(LNOTIFY_AFTER_COUNT), 0ULL); + write_hvwc_reg(window, VREG(LRX_WCRED), 0ULL); + write_hvwc_reg(window, VREG(LRX_WCRED_ADDER), 0ULL); + write_hvwc_reg(window, VREG(TX_WCRED), 0ULL); + write_hvwc_reg(window, VREG(TX_WCRED_ADDER), 0ULL); + write_hvwc_reg(window, VREG(LFIFO_SIZE), 0ULL); + write_hvwc_reg(window, VREG(WINCTL), 0ULL); + write_hvwc_reg(window, VREG(WIN_STATUS), 0ULL); + write_hvwc_reg(window, VREG(WIN_CTX_CACHING_CTL), 0ULL); + write_hvwc_reg(window, VREG(TX_RSVD_BUF_COUNT), 0ULL); + write_hvwc_reg(window, VREG(LRFIFO_WIN_PTR), 0ULL); + write_hvwc_reg(window, VREG(LNOTIFY_CTL), 0ULL); + write_hvwc_reg(window, VREG(LNOTIFY_PID), 0ULL); + write_hvwc_reg(window, VREG(LNOTIFY_LPID), 0ULL); + write_hvwc_reg(window, VREG(LNOTIFY_TID), 0ULL); + write_hvwc_reg(window, VREG(LNOTIFY_SCOPE), 0ULL); + write_hvwc_reg(window, VREG(NX_UTIL_ADDER), 0ULL); + + /* Skip read-only registers: NX_UTIL and NX_UTIL_SE */ + + /* + * The send and receive window credit adder registers are also + * accessible from HVWC and have been initialized above. We don't + * need to initialize from the OS/User Window Context, so skip + * following calls: + * + * write_uwc_reg(window, VREG(TX_WCRED_ADDER), 0ULL); + * write_uwc_reg(window, VREG(LRX_WCRED_ADDER), 0ULL); + */ +} + +/* + * Initialize window context registers related to Address Translation. + * These registers are common to send/receive windows although they + * differ for user/kernel windows. As we resolve the TODOs we may + * want to add fields to vas_winctx and move the initialization to + * init_vas_winctx_regs(). + */ +static void init_xlate_regs(struct vas_window *window, bool user_win) +{ + u64 lpcr, val; + + /* + * MSR_TA, MSR_US are false for both kernel and user. + * MSR_DR and MSR_PR are false for kernel. + */ + val = 0ULL; + val = SET_FIELD(VAS_XLATE_MSR_HV, val, 1); + val = SET_FIELD(VAS_XLATE_MSR_SF, val, 1); + if (user_win) { + val = SET_FIELD(VAS_XLATE_MSR_DR, val, 1); + val = SET_FIELD(VAS_XLATE_MSR_PR, val, 1); + } + write_hvwc_reg(window, VREG(XLATE_MSR), val); + + lpcr = mfspr(SPRN_LPCR); + val = 0ULL; + /* + * NOTE: From Section 5.7.8.1 Segment Lookaside Buffer of the + * Power ISA, v3.0B, Page size encoding is 0 = 4KB, 5 = 64KB. + * + * NOTE: From Section 1.3.1, Address Translation Context of the + * Nest MMU Workbook, LPCR_SC should be 0 for Power9. + */ + val = SET_FIELD(VAS_XLATE_LPCR_PAGE_SIZE, val, 5); + val = SET_FIELD(VAS_XLATE_LPCR_ISL, val, lpcr & LPCR_ISL); + val = SET_FIELD(VAS_XLATE_LPCR_TC, val, lpcr & LPCR_TC); + val = SET_FIELD(VAS_XLATE_LPCR_SC, val, 0); + write_hvwc_reg(window, VREG(XLATE_LPCR), val); + + /* + * Section 1.3.1 (Address translation Context) of NMMU workbook. + * 0b00 Hashed Page Table mode + * 0b01 Reserved + * 0b10 Radix on HPT + * 0b11 Radix on Radix + */ + val = 0ULL; + val = SET_FIELD(VAS_XLATE_MODE, val, radix_enabled() ? 3 : 2); + write_hvwc_reg(window, VREG(XLATE_CTL), val); + + /* + * TODO: Can we mfspr(AMR) even for user windows? + */ + val = 0ULL; + val = SET_FIELD(VAS_AMR, val, mfspr(SPRN_AMR)); + write_hvwc_reg(window, VREG(AMR), val); + + val = 0ULL; + val = SET_FIELD(VAS_SEIDR, val, 0); + write_hvwc_reg(window, VREG(SEIDR), val); +} + +/* + * Initialize Reserved Send Buffer Count for the send window. It involves + * writing to the register, reading it back to confirm that the hardware + * has enough buffers to reserve. See section 1.3.1.2.1 of VAS workbook. + * + * Since we can only make a best-effort attempt to fulfill the request, + * we don't return any errors if we cannot. + * + * TODO: Reserved (aka dedicated) send buffers are not supported yet. + */ +static void init_rsvd_tx_buf_count(struct vas_window *txwin, + struct vas_winctx *winctx) +{ + write_hvwc_reg(txwin, VREG(TX_RSVD_BUF_COUNT), 0ULL); +} + +/* + * init_winctx_regs() + * Initialize window context registers for a receive window. + * Except for caching control and marking window open, the registers + * are initialized in the order listed in Section 3.1.4 (Window Context + * Cache Register Details) of the VAS workbook although they don't need + * to be. + * + * Design note: For NX receive windows, NX allocates the FIFO buffer in OPAL + * (so that it can get a large contiguous area) and passes that buffer + * to kernel via device tree. We now write that buffer address to the + * FIFO BAR. Would it make sense to do this all in OPAL? i.e have OPAL + * write the per-chip RX FIFO addresses to the windows during boot-up + * as a one-time task? That could work for NX but what about other + * receivers? Let the receivers tell us the rx-fifo buffers for now. + */ +int init_winctx_regs(struct vas_window *window, struct vas_winctx *winctx) +{ + u64 val; + int fifo_size; + + reset_window_regs(window); + + val = 0ULL; + val = SET_FIELD(VAS_LPID, val, winctx->lpid); + write_hvwc_reg(window, VREG(LPID), val); + + val = 0ULL; + val = SET_FIELD(VAS_PID_ID, val, winctx->pidr); + write_hvwc_reg(window, VREG(PID), val); + + init_xlate_regs(window, winctx->user_win); + + val = 0ULL; + val = SET_FIELD(VAS_FAULT_TX_WIN, val, 0); + write_hvwc_reg(window, VREG(FAULT_TX_WIN), val); + + /* In PowerNV, interrupts go to HV. */ + write_hvwc_reg(window, VREG(OSU_INTR_SRC_RA), 0ULL); + + val = 0ULL; + val = SET_FIELD(VAS_HV_INTR_SRC_RA, val, winctx->irq_port); + write_hvwc_reg(window, VREG(HV_INTR_SRC_RA), val); + + val = 0ULL; + val = SET_FIELD(VAS_PSWID_EA_HANDLE, val, winctx->pswid); + write_hvwc_reg(window, VREG(PSWID), val); + + write_hvwc_reg(window, VREG(SPARE1), 0ULL); + write_hvwc_reg(window, VREG(SPARE2), 0ULL); + write_hvwc_reg(window, VREG(SPARE3), 0ULL); + + /* + * NOTE: VAS expects the FIFO address to be copied into the LFIFO_BAR + * register as is - do NOT shift the address into VAS_LFIFO_BAR + * bit fields! Ok to set the page migration select fields - + * VAS ignores the lower 10+ bits in the address anyway, because + * the minimum FIFO size is 1K? + * + * See also: Design note in function header. + */ + val = __pa(winctx->rx_fifo); + val = SET_FIELD(VAS_PAGE_MIGRATION_SELECT, val, 0); + write_hvwc_reg(window, VREG(LFIFO_BAR), val); + + val = 0ULL; + val = SET_FIELD(VAS_LDATA_STAMP, val, winctx->data_stamp); + write_hvwc_reg(window, VREG(LDATA_STAMP_CTL), val); + + val = 0ULL; + val = SET_FIELD(VAS_LDMA_TYPE, val, winctx->dma_type); + val = SET_FIELD(VAS_LDMA_FIFO_DISABLE, val, winctx->fifo_disable); + write_hvwc_reg(window, VREG(LDMA_CACHE_CTL), val); + + write_hvwc_reg(window, VREG(LRFIFO_PUSH), 0ULL); + write_hvwc_reg(window, VREG(CURR_MSG_COUNT), 0ULL); + write_hvwc_reg(window, VREG(LNOTIFY_AFTER_COUNT), 0ULL); + + val = 0ULL; + val = SET_FIELD(VAS_LRX_WCRED, val, winctx->wcreds_max); + write_hvwc_reg(window, VREG(LRX_WCRED), val); + + val = 0ULL; + val = SET_FIELD(VAS_TX_WCRED, val, winctx->wcreds_max); + write_hvwc_reg(window, VREG(TX_WCRED), val); + + write_hvwc_reg(window, VREG(LRX_WCRED_ADDER), 0ULL); + write_hvwc_reg(window, VREG(TX_WCRED_ADDER), 0ULL); + + fifo_size = winctx->rx_fifo_size / 1024; + + val = 0ULL; + val = SET_FIELD(VAS_LFIFO_SIZE, val, ilog2(fifo_size)); + write_hvwc_reg(window, VREG(LFIFO_SIZE), val); + + /* Update window control and caching control registers last so + * we mark the window open only after fully initializing it and + * pushing context to cache. + */ + + write_hvwc_reg(window, VREG(WIN_STATUS), 0ULL); + + init_rsvd_tx_buf_count(window, winctx); + + /* for a send window, point to the matching receive window */ + val = 0ULL; + val = SET_FIELD(VAS_LRX_WIN_ID, val, winctx->rx_win_id); + write_hvwc_reg(window, VREG(LRFIFO_WIN_PTR), val); + + write_hvwc_reg(window, VREG(SPARE4), 0ULL); + + val = 0ULL; + val = SET_FIELD(VAS_NOTIFY_DISABLE, val, winctx->notify_disable); + val = SET_FIELD(VAS_INTR_DISABLE, val, winctx->intr_disable); + val = SET_FIELD(VAS_NOTIFY_EARLY, val, winctx->notify_early); + val = SET_FIELD(VAS_NOTIFY_OSU_INTR, val, winctx->notify_os_intr_reg); + write_hvwc_reg(window, VREG(LNOTIFY_CTL), val); + + val = 0ULL; + val = SET_FIELD(VAS_LNOTIFY_PID, val, winctx->lnotify_pid); + write_hvwc_reg(window, VREG(LNOTIFY_PID), val); + + val = 0ULL; + val = SET_FIELD(VAS_LNOTIFY_LPID, val, winctx->lnotify_lpid); + write_hvwc_reg(window, VREG(LNOTIFY_LPID), val); + + val = 0ULL; + val = SET_FIELD(VAS_LNOTIFY_TID, val, winctx->lnotify_tid); + write_hvwc_reg(window, VREG(LNOTIFY_TID), val); + + val = 0ULL; + val = SET_FIELD(VAS_LNOTIFY_MIN_SCOPE, val, winctx->min_scope); + val = SET_FIELD(VAS_LNOTIFY_MAX_SCOPE, val, winctx->max_scope); + write_hvwc_reg(window, VREG(LNOTIFY_SCOPE), val); + + /* Skip read-only registers NX_UTIL and NX_UTIL_SE */ + + write_hvwc_reg(window, VREG(SPARE5), 0ULL); + write_hvwc_reg(window, VREG(NX_UTIL_ADDER), 0ULL); + write_hvwc_reg(window, VREG(SPARE6), 0ULL); + + /* Finally, push window context to memory and... */ + val = 0ULL; + val = SET_FIELD(VAS_PUSH_TO_MEM, val, 1); + write_hvwc_reg(window, VREG(WIN_CTX_CACHING_CTL), val); + + /* ... mark the window open for business */ + val = 0ULL; + val = SET_FIELD(VAS_WINCTL_REJ_NO_CREDIT, val, winctx->rej_no_credit); + val = SET_FIELD(VAS_WINCTL_PIN, val, winctx->pin_win); + val = SET_FIELD(VAS_WINCTL_TX_WCRED_MODE, val, winctx->tx_wcred_mode); + val = SET_FIELD(VAS_WINCTL_RX_WCRED_MODE, val, winctx->rx_wcred_mode); + val = SET_FIELD(VAS_WINCTL_TX_WORD_MODE, val, winctx->tx_word_mode); + val = SET_FIELD(VAS_WINCTL_RX_WORD_MODE, val, winctx->rx_word_mode); + val = SET_FIELD(VAS_WINCTL_FAULT_WIN, val, winctx->fault_win); + val = SET_FIELD(VAS_WINCTL_NX_WIN, val, winctx->nx_win); + val = SET_FIELD(VAS_WINCTL_OPEN, val, 1); + write_hvwc_reg(window, VREG(WINCTL), val); + + return 0; +} + +static void vas_release_window_id(struct ida *ida, int winid) +{ + ida_free(ida, winid); +} + +static int vas_assign_window_id(struct ida *ida) +{ + int winid = ida_alloc_max(ida, VAS_WINDOWS_PER_CHIP - 1, GFP_KERNEL); + + if (winid == -ENOSPC) { + pr_err("Too many (%d) open windows\n", VAS_WINDOWS_PER_CHIP); + return -EAGAIN; + } + + return winid; +} + +static void vas_window_free(struct vas_window *window) +{ + int winid = window->winid; + struct vas_instance *vinst = window->vinst; + + unmap_winctx_mmio_bars(window); + + vas_window_free_dbgdir(window); + + kfree(window); + + vas_release_window_id(&vinst->ida, winid); +} + +static struct vas_window *vas_window_alloc(struct vas_instance *vinst) +{ + int winid; + struct vas_window *window; + + winid = vas_assign_window_id(&vinst->ida); + if (winid < 0) + return ERR_PTR(winid); + + window = kzalloc(sizeof(*window), GFP_KERNEL); + if (!window) + goto out_free; + + window->vinst = vinst; + window->winid = winid; + + if (map_winctx_mmio_bars(window)) + goto out_free; + + vas_window_init_dbgdir(window); + + return window; + +out_free: + kfree(window); + vas_release_window_id(&vinst->ida, winid); + return ERR_PTR(-ENOMEM); +} + +static void put_rx_win(struct vas_window *rxwin) +{ + /* Better not be a send window! */ + WARN_ON_ONCE(rxwin->tx_win); + + atomic_dec(&rxwin->num_txwins); +} + +/* + * Find the user space receive window given the @pswid. + * - We must have a valid vasid and it must belong to this instance. + * (so both send and receive windows are on the same VAS instance) + * - The window must refer to an OPEN, FTW, RECEIVE window. + * + * NOTE: We access ->windows[] table and assume that vinst->mutex is held. + */ +static struct vas_window *get_user_rxwin(struct vas_instance *vinst, u32 pswid) +{ + int vasid, winid; + struct vas_window *rxwin; + + decode_pswid(pswid, &vasid, &winid); + + if (vinst->vas_id != vasid) + return ERR_PTR(-EINVAL); + + rxwin = vinst->windows[winid]; + + if (!rxwin || rxwin->tx_win || rxwin->cop != VAS_COP_TYPE_FTW) + return ERR_PTR(-EINVAL); + + return rxwin; +} + +/* + * Get the VAS receive window associated with NX engine identified + * by @cop and if applicable, @pswid. + * + * See also function header of set_vinst_win(). + */ +static struct vas_window *get_vinst_rxwin(struct vas_instance *vinst, + enum vas_cop_type cop, u32 pswid) +{ + struct vas_window *rxwin; + + mutex_lock(&vinst->mutex); + + if (cop == VAS_COP_TYPE_FTW) + rxwin = get_user_rxwin(vinst, pswid); + else + rxwin = vinst->rxwin[cop] ?: ERR_PTR(-EINVAL); + + if (!IS_ERR(rxwin)) + atomic_inc(&rxwin->num_txwins); + + mutex_unlock(&vinst->mutex); + + return rxwin; +} + +/* + * We have two tables of windows in a VAS instance. The first one, + * ->windows[], contains all the windows in the instance and allows + * looking up a window by its id. It is used to look up send windows + * during fault handling and receive windows when pairing user space + * send/receive windows. + * + * The second table, ->rxwin[], contains receive windows that are + * associated with NX engines. This table has VAS_COP_TYPE_MAX + * entries and is used to look up a receive window by its + * coprocessor type. + * + * Here, we save @window in the ->windows[] table. If it is a receive + * window, we also save the window in the ->rxwin[] table. + */ +static void set_vinst_win(struct vas_instance *vinst, + struct vas_window *window) +{ + int id = window->winid; + + mutex_lock(&vinst->mutex); + + /* + * There should only be one receive window for a coprocessor type + * unless its a user (FTW) window. + */ + if (!window->user_win && !window->tx_win) { + WARN_ON_ONCE(vinst->rxwin[window->cop]); + vinst->rxwin[window->cop] = window; + } + + WARN_ON_ONCE(vinst->windows[id] != NULL); + vinst->windows[id] = window; + + mutex_unlock(&vinst->mutex); +} + +/* + * Clear this window from the table(s) of windows for this VAS instance. + * See also function header of set_vinst_win(). + */ +static void clear_vinst_win(struct vas_window *window) +{ + int id = window->winid; + struct vas_instance *vinst = window->vinst; + + mutex_lock(&vinst->mutex); + + if (!window->user_win && !window->tx_win) { + WARN_ON_ONCE(!vinst->rxwin[window->cop]); + vinst->rxwin[window->cop] = NULL; + } + + WARN_ON_ONCE(vinst->windows[id] != window); + vinst->windows[id] = NULL; + + mutex_unlock(&vinst->mutex); +} + +static void init_winctx_for_rxwin(struct vas_window *rxwin, + struct vas_rx_win_attr *rxattr, + struct vas_winctx *winctx) +{ + /* + * We first zero (memset()) all fields and only set non-zero fields. + * Following fields are 0/false but maybe deserve a comment: + * + * ->notify_os_intr_reg In powerNV, send intrs to HV + * ->notify_disable False for NX windows + * ->intr_disable False for Fault Windows + * ->xtra_write False for NX windows + * ->notify_early NA for NX windows + * ->rsvd_txbuf_count NA for Rx windows + * ->lpid, ->pid, ->tid NA for Rx windows + */ + + memset(winctx, 0, sizeof(struct vas_winctx)); + + winctx->rx_fifo = rxattr->rx_fifo; + winctx->rx_fifo_size = rxattr->rx_fifo_size; + winctx->wcreds_max = rxwin->wcreds_max; + winctx->pin_win = rxattr->pin_win; + + winctx->nx_win = rxattr->nx_win; + winctx->fault_win = rxattr->fault_win; + winctx->user_win = rxattr->user_win; + winctx->rej_no_credit = rxattr->rej_no_credit; + winctx->rx_word_mode = rxattr->rx_win_ord_mode; + winctx->tx_word_mode = rxattr->tx_win_ord_mode; + winctx->rx_wcred_mode = rxattr->rx_wcred_mode; + winctx->tx_wcred_mode = rxattr->tx_wcred_mode; + winctx->notify_early = rxattr->notify_early; + + if (winctx->nx_win) { + winctx->data_stamp = true; + winctx->intr_disable = true; + winctx->pin_win = true; + + WARN_ON_ONCE(winctx->fault_win); + WARN_ON_ONCE(!winctx->rx_word_mode); + WARN_ON_ONCE(!winctx->tx_word_mode); + WARN_ON_ONCE(winctx->notify_after_count); + } else if (winctx->fault_win) { + winctx->notify_disable = true; + } else if (winctx->user_win) { + /* + * Section 1.8.1 Low Latency Core-Core Wake up of + * the VAS workbook: + * + * - disable credit checks ([tr]x_wcred_mode = false) + * - disable FIFO writes + * - enable ASB_Notify, disable interrupt + */ + winctx->fifo_disable = true; + winctx->intr_disable = true; + winctx->rx_fifo = NULL; + } + + winctx->lnotify_lpid = rxattr->lnotify_lpid; + winctx->lnotify_pid = rxattr->lnotify_pid; + winctx->lnotify_tid = rxattr->lnotify_tid; + winctx->pswid = rxattr->pswid; + winctx->dma_type = VAS_DMA_TYPE_INJECT; + winctx->tc_mode = rxattr->tc_mode; + + winctx->min_scope = VAS_SCOPE_LOCAL; + winctx->max_scope = VAS_SCOPE_VECTORED_GROUP; +} + +static bool rx_win_args_valid(enum vas_cop_type cop, + struct vas_rx_win_attr *attr) +{ + pr_debug("Rxattr: fault %d, notify %d, intr %d, early %d, fifo %d\n", + attr->fault_win, attr->notify_disable, + attr->intr_disable, attr->notify_early, + attr->rx_fifo_size); + + if (cop >= VAS_COP_TYPE_MAX) + return false; + + if (cop != VAS_COP_TYPE_FTW && + attr->rx_fifo_size < VAS_RX_FIFO_SIZE_MIN) + return false; + + if (attr->rx_fifo_size > VAS_RX_FIFO_SIZE_MAX) + return false; + + if (attr->wcreds_max > VAS_RX_WCREDS_MAX) + return false; + + if (attr->nx_win) { + /* cannot be fault or user window if it is nx */ + if (attr->fault_win || attr->user_win) + return false; + /* + * Section 3.1.4.32: NX Windows must not disable notification, + * and must not enable interrupts or early notification. + */ + if (attr->notify_disable || !attr->intr_disable || + attr->notify_early) + return false; + } else if (attr->fault_win) { + /* cannot be both fault and user window */ + if (attr->user_win) + return false; + + /* + * Section 3.1.4.32: Fault windows must disable notification + * but not interrupts. + */ + if (!attr->notify_disable || attr->intr_disable) + return false; + + } else if (attr->user_win) { + /* + * User receive windows are only for fast-thread-wakeup + * (FTW). They don't need a FIFO and must disable interrupts + */ + if (attr->rx_fifo || attr->rx_fifo_size || !attr->intr_disable) + return false; + } else { + /* Rx window must be one of NX or Fault or User window. */ + return false; + } + + return true; +} + +void vas_init_rx_win_attr(struct vas_rx_win_attr *rxattr, enum vas_cop_type cop) +{ + memset(rxattr, 0, sizeof(*rxattr)); + + if (cop == VAS_COP_TYPE_842 || cop == VAS_COP_TYPE_842_HIPRI) { + rxattr->pin_win = true; + rxattr->nx_win = true; + rxattr->fault_win = false; + rxattr->intr_disable = true; + rxattr->rx_wcred_mode = true; + rxattr->tx_wcred_mode = true; + rxattr->rx_win_ord_mode = true; + rxattr->tx_win_ord_mode = true; + } else if (cop == VAS_COP_TYPE_FAULT) { + rxattr->pin_win = true; + rxattr->fault_win = true; + rxattr->notify_disable = true; + rxattr->rx_wcred_mode = true; + rxattr->tx_wcred_mode = true; + rxattr->rx_win_ord_mode = true; + rxattr->tx_win_ord_mode = true; + } else if (cop == VAS_COP_TYPE_FTW) { + rxattr->user_win = true; + rxattr->intr_disable = true; + + /* + * As noted in the VAS Workbook we disable credit checks. + * If we enable credit checks in the future, we must also + * implement a mechanism to return the user credits or new + * paste operations will fail. + */ + } +} +EXPORT_SYMBOL_GPL(vas_init_rx_win_attr); + +struct vas_window *vas_rx_win_open(int vasid, enum vas_cop_type cop, + struct vas_rx_win_attr *rxattr) +{ + struct vas_window *rxwin; + struct vas_winctx winctx; + struct vas_instance *vinst; + + trace_vas_rx_win_open(current, vasid, cop, rxattr); + + if (!rx_win_args_valid(cop, rxattr)) + return ERR_PTR(-EINVAL); + + vinst = find_vas_instance(vasid); + if (!vinst) { + pr_devel("vasid %d not found!\n", vasid); + return ERR_PTR(-EINVAL); + } + pr_devel("Found instance %d\n", vasid); + + rxwin = vas_window_alloc(vinst); + if (IS_ERR(rxwin)) { + pr_devel("Unable to allocate memory for Rx window\n"); + return rxwin; + } + + rxwin->tx_win = false; + rxwin->nx_win = rxattr->nx_win; + rxwin->user_win = rxattr->user_win; + rxwin->cop = cop; + rxwin->wcreds_max = rxattr->wcreds_max ?: VAS_WCREDS_DEFAULT; + if (rxattr->user_win) + rxwin->pid = task_pid_vnr(current); + + init_winctx_for_rxwin(rxwin, rxattr, &winctx); + init_winctx_regs(rxwin, &winctx); + + set_vinst_win(vinst, rxwin); + + return rxwin; +} +EXPORT_SYMBOL_GPL(vas_rx_win_open); + +void vas_init_tx_win_attr(struct vas_tx_win_attr *txattr, enum vas_cop_type cop) +{ + memset(txattr, 0, sizeof(*txattr)); + + if (cop == VAS_COP_TYPE_842 || cop == VAS_COP_TYPE_842_HIPRI) { + txattr->rej_no_credit = false; + txattr->rx_wcred_mode = true; + txattr->tx_wcred_mode = true; + txattr->rx_win_ord_mode = true; + txattr->tx_win_ord_mode = true; + } else if (cop == VAS_COP_TYPE_FTW) { + txattr->user_win = true; + } +} +EXPORT_SYMBOL_GPL(vas_init_tx_win_attr); + +static void init_winctx_for_txwin(struct vas_window *txwin, + struct vas_tx_win_attr *txattr, + struct vas_winctx *winctx) +{ + /* + * We first zero all fields and only set non-zero ones. Following + * are some fields set to 0/false for the stated reason: + * + * ->notify_os_intr_reg In powernv, send intrs to HV + * ->rsvd_txbuf_count Not supported yet. + * ->notify_disable False for NX windows + * ->xtra_write False for NX windows + * ->notify_early NA for NX windows + * ->lnotify_lpid NA for Tx windows + * ->lnotify_pid NA for Tx windows + * ->lnotify_tid NA for Tx windows + * ->tx_win_cred_mode Ignore for now for NX windows + * ->rx_win_cred_mode Ignore for now for NX windows + */ + memset(winctx, 0, sizeof(struct vas_winctx)); + + winctx->wcreds_max = txwin->wcreds_max; + + winctx->user_win = txattr->user_win; + winctx->nx_win = txwin->rxwin->nx_win; + winctx->pin_win = txattr->pin_win; + winctx->rej_no_credit = txattr->rej_no_credit; + winctx->rsvd_txbuf_enable = txattr->rsvd_txbuf_enable; + + winctx->rx_wcred_mode = txattr->rx_wcred_mode; + winctx->tx_wcred_mode = txattr->tx_wcred_mode; + winctx->rx_word_mode = txattr->rx_win_ord_mode; + winctx->tx_word_mode = txattr->tx_win_ord_mode; + winctx->rsvd_txbuf_count = txattr->rsvd_txbuf_count; + + winctx->intr_disable = true; + if (winctx->nx_win) + winctx->data_stamp = true; + + winctx->lpid = txattr->lpid; + winctx->pidr = txattr->pidr; + winctx->rx_win_id = txwin->rxwin->winid; + + winctx->dma_type = VAS_DMA_TYPE_INJECT; + winctx->tc_mode = txattr->tc_mode; + winctx->min_scope = VAS_SCOPE_LOCAL; + winctx->max_scope = VAS_SCOPE_VECTORED_GROUP; + + winctx->pswid = 0; +} + +static bool tx_win_args_valid(enum vas_cop_type cop, + struct vas_tx_win_attr *attr) +{ + if (attr->tc_mode != VAS_THRESH_DISABLED) + return false; + + if (cop > VAS_COP_TYPE_MAX) + return false; + + if (attr->wcreds_max > VAS_TX_WCREDS_MAX) + return false; + + if (attr->user_win && + (cop != VAS_COP_TYPE_FTW || attr->rsvd_txbuf_count)) + return false; + + return true; +} + +struct vas_window *vas_tx_win_open(int vasid, enum vas_cop_type cop, + struct vas_tx_win_attr *attr) +{ + int rc; + struct vas_window *txwin; + struct vas_window *rxwin; + struct vas_winctx winctx; + struct vas_instance *vinst; + + trace_vas_tx_win_open(current, vasid, cop, attr); + + if (!tx_win_args_valid(cop, attr)) + return ERR_PTR(-EINVAL); + + /* + * If caller did not specify a vasid but specified the PSWID of a + * receive window (applicable only to FTW windows), use the vasid + * from that receive window. + */ + if (vasid == -1 && attr->pswid) + decode_pswid(attr->pswid, &vasid, NULL); + + vinst = find_vas_instance(vasid); + if (!vinst) { + pr_devel("vasid %d not found!\n", vasid); + return ERR_PTR(-EINVAL); + } + + rxwin = get_vinst_rxwin(vinst, cop, attr->pswid); + if (IS_ERR(rxwin)) { + pr_devel("No RxWin for vasid %d, cop %d\n", vasid, cop); + return rxwin; + } + + txwin = vas_window_alloc(vinst); + if (IS_ERR(txwin)) { + rc = PTR_ERR(txwin); + goto put_rxwin; + } + + txwin->cop = cop; + txwin->tx_win = 1; + txwin->rxwin = rxwin; + txwin->nx_win = txwin->rxwin->nx_win; + txwin->pid = attr->pid; + txwin->user_win = attr->user_win; + txwin->wcreds_max = attr->wcreds_max ?: VAS_WCREDS_DEFAULT; + + init_winctx_for_txwin(txwin, attr, &winctx); + + init_winctx_regs(txwin, &winctx); + + /* + * If its a kernel send window, map the window address into the + * kernel's address space. For user windows, user must issue an + * mmap() to map the window into their address space. + * + * NOTE: If kernel ever resubmits a user CRB after handling a page + * fault, we will need to map this into kernel as well. + */ + if (!txwin->user_win) { + txwin->paste_kaddr = map_paste_region(txwin); + if (IS_ERR(txwin->paste_kaddr)) { + rc = PTR_ERR(txwin->paste_kaddr); + goto free_window; + } + } else { + /* + * A user mapping must ensure that context switch issues + * CP_ABORT for this thread. + */ + rc = set_thread_uses_vas(); + if (rc) + goto free_window; + } + + set_vinst_win(vinst, txwin); + + return txwin; + +free_window: + vas_window_free(txwin); + +put_rxwin: + put_rx_win(rxwin); + return ERR_PTR(rc); + +} +EXPORT_SYMBOL_GPL(vas_tx_win_open); + +int vas_copy_crb(void *crb, int offset) +{ + return vas_copy(crb, offset); +} +EXPORT_SYMBOL_GPL(vas_copy_crb); + +#define RMA_LSMP_REPORT_ENABLE PPC_BIT(53) +int vas_paste_crb(struct vas_window *txwin, int offset, bool re) +{ + int rc; + void *addr; + uint64_t val; + + trace_vas_paste_crb(current, txwin); + + /* + * Only NX windows are supported for now and hardware assumes + * report-enable flag is set for NX windows. Ensure software + * complies too. + */ + WARN_ON_ONCE(txwin->nx_win && !re); + + addr = txwin->paste_kaddr; + if (re) { + /* + * Set the REPORT_ENABLE bit (equivalent to writing + * to 1K offset of the paste address) + */ + val = SET_FIELD(RMA_LSMP_REPORT_ENABLE, 0ULL, 1); + addr += val; + } + + /* + * Map the raw CR value from vas_paste() to an error code (there + * is just pass or fail for now though). + */ + rc = vas_paste(addr, offset); + if (rc == 2) + rc = 0; + else + rc = -EINVAL; + + pr_debug("Txwin #%d: Msg count %llu\n", txwin->winid, + read_hvwc_reg(txwin, VREG(LRFIFO_PUSH))); + + return rc; +} +EXPORT_SYMBOL_GPL(vas_paste_crb); + +/* + * If credit checking is enabled for this window, poll for the return + * of window credits (i.e for NX engines to process any outstanding CRBs). + * Since NX-842 waits for the CRBs to be processed before closing the + * window, we should not have to wait for too long. + * + * TODO: We retry in 10ms intervals now. We could/should probably peek at + * the VAS_LRFIFO_PUSH_OFFSET register to get an estimate of pending + * CRBs on the FIFO and compute the delay dynamically on each retry. + * But that is not really needed until we support NX-GZIP access from + * user space. (NX-842 driver waits for CSB and Fast thread-wakeup + * doesn't use credit checking). + */ +static void poll_window_credits(struct vas_window *window) +{ + u64 val; + int creds, mode; + + val = read_hvwc_reg(window, VREG(WINCTL)); + if (window->tx_win) + mode = GET_FIELD(VAS_WINCTL_TX_WCRED_MODE, val); + else + mode = GET_FIELD(VAS_WINCTL_RX_WCRED_MODE, val); + + if (!mode) + return; +retry: + if (window->tx_win) { + val = read_hvwc_reg(window, VREG(TX_WCRED)); + creds = GET_FIELD(VAS_TX_WCRED, val); + } else { + val = read_hvwc_reg(window, VREG(LRX_WCRED)); + creds = GET_FIELD(VAS_LRX_WCRED, val); + } + + if (creds < window->wcreds_max) { + val = 0; + set_current_state(TASK_UNINTERRUPTIBLE); + schedule_timeout(msecs_to_jiffies(10)); + goto retry; + } +} + +/* + * Wait for the window to go to "not-busy" state. It should only take a + * short time to queue a CRB, so window should not be busy for too long. + * Trying 5ms intervals. + */ +static void poll_window_busy_state(struct vas_window *window) +{ + int busy; + u64 val; + +retry: + val = read_hvwc_reg(window, VREG(WIN_STATUS)); + busy = GET_FIELD(VAS_WIN_BUSY, val); + if (busy) { + val = 0; + set_current_state(TASK_UNINTERRUPTIBLE); + schedule_timeout(msecs_to_jiffies(5)); + goto retry; + } +} + +/* + * Have the hardware cast a window out of cache and wait for it to + * be completed. + * + * NOTE: It can take a relatively long time to cast the window context + * out of the cache. It is not strictly necessary to cast out if: + * + * - we clear the "Pin Window" bit (so hardware is free to evict) + * + * - we re-initialize the window context when it is reassigned. + * + * We do the former in vas_win_close() and latter in vas_win_open(). + * So, ignoring the cast-out for now. We can add it as needed. If + * casting out becomes necessary we should consider offloading the + * job to a worker thread, so the window close can proceed quickly. + */ +static void poll_window_castout(struct vas_window *window) +{ + /* stub for now */ +} + +/* + * Unpin and close a window so no new requests are accepted and the + * hardware can evict this window from cache if necessary. + */ +static void unpin_close_window(struct vas_window *window) +{ + u64 val; + + val = read_hvwc_reg(window, VREG(WINCTL)); + val = SET_FIELD(VAS_WINCTL_PIN, val, 0); + val = SET_FIELD(VAS_WINCTL_OPEN, val, 0); + write_hvwc_reg(window, VREG(WINCTL), val); +} + +/* + * Close a window. + * + * See Section 1.12.1 of VAS workbook v1.05 for details on closing window: + * - Disable new paste operations (unmap paste address) + * - Poll for the "Window Busy" bit to be cleared + * - Clear the Open/Enable bit for the Window. + * - Poll for return of window Credits (implies FIFO empty for Rx win?) + * - Unpin and cast window context out of cache + * + * Besides the hardware, kernel has some bookkeeping of course. + */ +int vas_win_close(struct vas_window *window) +{ + if (!window) + return 0; + + if (!window->tx_win && atomic_read(&window->num_txwins) != 0) { + pr_devel("Attempting to close an active Rx window!\n"); + WARN_ON_ONCE(1); + return -EBUSY; + } + + unmap_paste_region(window); + + clear_vinst_win(window); + + poll_window_busy_state(window); + + unpin_close_window(window); + + poll_window_credits(window); + + poll_window_castout(window); + + /* if send window, drop reference to matching receive window */ + if (window->tx_win) + put_rx_win(window->rxwin); + + vas_window_free(window); + + return 0; +} +EXPORT_SYMBOL_GPL(vas_win_close); + +/* + * Return a system-wide unique window id for the window @win. + */ +u32 vas_win_id(struct vas_window *win) +{ + return encode_pswid(win->vinst->vas_id, win->winid); +} +EXPORT_SYMBOL_GPL(vas_win_id); |