Define helpers to initialize window context registers of the VAS
hardware. These will be used in follow-on patches when opening/closing
VAS windows.
Signed-off-by: Sukadev Bhattiprolu <suka...@linux.vnet.ibm.com>
---
Changelog[v3]
- Have caller, rather than init_xlate_regs() reset window regs
so we don't reset any settings caller may already have set.
- Translation mode should be 0x3 (0b11) not 0x11.
- Skip initilaizing read-only registers NX_UTIL and NX_UTIL_SE
- Skip initializing adder registers from UWC - they are already
initialized from the HVWC.
- Check winctx->user_win when setting translation registers
---
drivers/misc/vas/vas-internal.h | 59 ++++++-
drivers/misc/vas/vas-window.c | 334 ++++++++++++++++++++++++++++++++++++++++
2 files changed, 390 insertions(+), 3 deletions(-)
diff --git a/drivers/misc/vas/vas-internal.h b/drivers/misc/vas/vas-internal.h
index 15b62e0..8e721df 100644
--- a/drivers/misc/vas/vas-internal.h
+++ b/drivers/misc/vas/vas-internal.h
@@ -11,6 +11,7 @@
#define VAS_INTERNAL_H
#include <linux/atomic.h>
#include <linux/idr.h>
+#include <linux/io.h>
#include <asm/vas.h>
#ifdef CONFIG_PPC_4K_PAGES
@@ -336,9 +337,6 @@ struct vas_window {
/* Feilds applicable only to receive windows */
enum vas_cop_type cop;
atomic_t num_txwins;
-
- int32_t hwirq;
- uint64_t irq_port;
};
/*
@@ -392,4 +390,59 @@ struct vas_winctx {
extern int vas_initialized;
extern int vas_window_reset(struct vas_instance *vinst, int winid);
extern struct vas_instance *find_vas_instance(int vasid);
+
+/*
+ * VREG(x):
+ * Expand a register's short name (eg: LPID) into two parameters:
+ * - the register's short name in string form ("LPID"), and
+ * - the name of the macro (eg: VAS_LPID_OFFSET), defining the
+ * register's offset in the window context
+ */
+#define VREG_SFX(n, s) __stringify(n), VAS_##n##s
+#define VREG(r) VREG_SFX(r, _OFFSET)
+
+#ifndef vas_debug
+static inline void vas_log_write(struct vas_window *win, char *name,
+ void *regptr, uint64_t val)
+{
+ if (val)
+ pr_err("%swin #%d: %s reg %p, val 0x%llx\n",
+ win->tx_win ? "Tx" : "Rx", win->winid, name,
+ regptr, val);
+}
+
+#else /* vas_debug */
+
+#define vas_log_write(win, name, reg, val)
+
+#endif /* vas_debug */
+
+static inline void write_uwc_reg(struct vas_window *win, char *name,
+ int32_t reg, uint64_t val)
+{
+ void *regptr;
+
+ regptr = win->uwc_map + reg;
+ vas_log_write(win, name, regptr, val);
+
+ out_be64(regptr, val);
+}
+
+static inline void write_hvwc_reg(struct vas_window *win, char *name,
+ int32_t reg, uint64_t val)
+{
+ void *regptr;
+
+ regptr = win->hvwc_map + reg;
+ vas_log_write(win, name, regptr, val);
+
+ out_be64(regptr, val);
+}
+
+static inline uint64_t read_hvwc_reg(struct vas_window *win,
+ char *name __maybe_unused, int32_t reg)
+{
+ return in_be64(win->hvwc_map+reg);
+}
+
#endif
diff --git a/drivers/misc/vas/vas-window.c b/drivers/misc/vas/vas-window.c
index 32dd1d0..edf5c9f 100644
--- a/drivers/misc/vas/vas-window.c
+++ b/drivers/misc/vas/vas-window.c
@@ -14,6 +14,8 @@
#include <asm/vas.h>
#include "vas-internal.h"
+static int fault_winid;
+
/*
* Compute the paste address region for the window @window using the
* ->win_base_addr and ->win_id_shift we got from device tree.
@@ -138,6 +140,338 @@ int map_wc_mmio_bars(struct vas_window *window)
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 (or is that only in Simics?).
+ */
+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(SPARE1), 0ULL);
+ write_hvwc_reg(window, VREG(SPARE2), 0ULL);
+ write_hvwc_reg(window, VREG(SPARE3), 0ULL);
+ write_hvwc_reg(window, VREG(SPARE4), 0ULL);
+ write_hvwc_reg(window, VREG(SPARE5), 0ULL);
+ write_hvwc_reg(window, VREG(SPARE6), 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)
+{
+ uint64_t lpcr, msr, val;
+
+ msr = mfmsr();
+ WARN_ON_ONCE(!(msr & MSR_SF));
+ val = 0ULL;
+ if (user_win) {
+ val = SET_FIELD(VAS_XLATE_MSR_DR, val, true);
+ val = SET_FIELD(VAS_XLATE_MSR_TA, val, false);
+ val = SET_FIELD(VAS_XLATE_MSR_PR, val, true);
+ val = SET_FIELD(VAS_XLATE_MSR_US, val, false);
+ val = SET_FIELD(VAS_XLATE_MSR_HV, val, true);
+ val = SET_FIELD(VAS_XLATE_MSR_SF, val, true);
+ val = SET_FIELD(VAS_XLATE_MSR_UV, val, false);
+ } else {
+ val = SET_FIELD(VAS_XLATE_MSR_DR, val, false);
+ val = SET_FIELD(VAS_XLATE_MSR_TA, val, false);
+ val = SET_FIELD(VAS_XLATE_MSR_PR, val, msr & MSR_PR);
+ val = SET_FIELD(VAS_XLATE_MSR_US, val, false);
+ val = SET_FIELD(VAS_XLATE_MSR_HV, val, true);
+ val = SET_FIELD(VAS_XLATE_MSR_SF, val, true);
+ val = SET_FIELD(VAS_XLATE_MSR_UV, val, false);
+ }
+ write_hvwc_reg(window, VREG(XLATE_MSR), val);
+
+ lpcr = mfspr(SPRN_LPCR);
+ val = 0ULL;
+ /*
+ * NOTE: From Section 5.7.6.1 Segment Lookaside Buffer of the
+ * Power ISA, v2.07, 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 - not supported in P9
+ * 0b11 Radix on Radix (only mode supported in Linux on P9).
+ */
+ val = 0ULL;
+ val = SET_FIELD(VAS_XLATE_MODE, val, 0x3);
+ 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);
+
+ /*
+ * TODO: Assuming Secure Executable ID Register (SEIDR) is only used
+ * in the ultravisor mode. Since MSR(UV) is 0 for now, set SEIDR
+ * to 0 as well, although we should 'mfspr(SEIDR)' at some point.
+ */
+ 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);
+}
+
+/*
+ * Compute the log2() of the FIFO size expressed as kilobytes. It is intended
+ * to be used to initialize the Local FIFO Size Register defined in Section
+ * 3.14.25 of the VAS Workbook.
+ */
+static int map_fifo_size_to_reg(int fifo_size)
+{
+ int kb;
+ int map;
+
+ kb = fifo_size / 1024;
+ if (!kb)
+ kb = 1;
+
+ map = -1;
+ while (kb) {
+ kb >>= 1;
+ map++;
+ }
+
+ return map;
+}
+
+/*
+ * 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)
+{
+ uint64_t 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, fault_winid);
+ 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);
+
+ /* See also: Design note in function header */
+ val = 0ULL;
+ val = SET_FIELD(VAS_LFIFO_BAR, 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);
+ 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);
+
+ val = 0ULL;
+ fifo_size = winctx->rx_fifo_size;
+ val = SET_FIELD(VAS_LFIFO_SIZE, val, map_fifo_size_to_reg(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;
+}
+
/* stub for now */
int vas_window_reset(struct vas_instance *vinst, int winid)
{
--
2.7.4
