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ubuntu-linux-kernel/arch/powerpc/platforms/powernv/vas-window.c

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2024-04-01 15:06:58 +00:00
/*
* 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"
/*
* 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 DEFINE_SPINLOCK(vas_ida_lock);
static void vas_release_window_id(struct ida *ida, int winid)
{
spin_lock(&vas_ida_lock);
ida_remove(ida, winid);
spin_unlock(&vas_ida_lock);
}
static int vas_assign_window_id(struct ida *ida)
{
int rc, winid;
do {
rc = ida_pre_get(ida, GFP_KERNEL);
if (!rc)
return -EAGAIN;
spin_lock(&vas_ida_lock);
rc = ida_get_new(ida, &winid);
spin_unlock(&vas_ida_lock);
} while (rc == -EAGAIN);
if (rc)
return rc;
if (winid > VAS_WINDOWS_PER_CHIP) {
pr_err("Too many (%d) open windows\n", winid);
vas_release_window_id(ida, winid);
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;
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;
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;
}
}
/*
* Now that we have a send window, ensure context switch issues
* CP_ABORT for this thread.
*/
rc = -EINVAL;
if (set_thread_uses_vas() < 0)
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;
/*
* 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);