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+/*
+ * 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.
+ */
+
+#ifndef _VAS_H
+#define _VAS_H
+#include <linux/atomic.h>
+#include <linux/idr.h>
+#include <asm/vas.h>
+#include <linux/io.h>
+
+/*
+ * Overview of Virtual Accelerator Switchboard (VAS).
+ *
+ * VAS is a hardware "switchboard" that allows senders and receivers to
+ * exchange messages with _minimal_ kernel involvment. The receivers are
+ * typically NX coprocessor engines that perform compression or encryption
+ * in hardware, but receivers can also be other software threads.
+ *
+ * Senders are user/kernel threads that submit compression/encryption or
+ * other requests to the receivers. Senders must format their messages as
+ * Coprocessor Request Blocks (CRB)s and submit them using the "copy" and
+ * "paste" instructions which were introduced in Power9.
+ *
+ * A Power node can have (upto?) 8 Power chips. There is one instance of
+ * VAS in each Power9 chip. Each instance of VAS has 64K windows or ports,
+ * Senders and receivers must each connect to a separate window before they
+ * can exchange messages through the switchboard.
+ *
+ * Each window is described by two types of window contexts:
+ *
+ * Hypervisor Window Context (HVWC) of size VAS_HVWC_SIZE bytes
+ *
+ * OS/User Window Context (UWC) of size VAS_UWC_SIZE bytes.
+ *
+ * A window context can be viewed as a set of 64-bit registers. The settings
+ * in these registers configure/control/determine the behavior of the VAS
+ * hardware when messages are sent/received through the window. The registers
+ * in the HVWC are configured by the kernel while the registers in the UWC can
+ * be configured by the kernel or by the user space application that is using
+ * the window.
+ *
+ * The HVWCs for all windows on a specific instance of VAS are in a contiguous
+ * range of hardware addresses or Base address region (BAR) referred to as the
+ * HVWC BAR for the instance. Similarly the UWCs for all windows on an instance
+ * are referred to as the UWC BAR for the instance.
+ *
+ * The two BARs for each instance are defined Power9 MMIO Ranges spreadsheet
+ * and available to the kernel in the VAS node's "reg" property in the device
+ * tree:
+ *
+ * /proc/device-tree/vasm@.../reg
+ *
+ * (see vas_probe() for details on the reg property).
+ *
+ * The kernel maps the HVWC and UWC BAR regions into the kernel address
+ * space (hvwc_map and uwc_map). The kernel can then access the window
+ * contexts of a specific window using:
+ *
+ * hvwc = hvwc_map + winid * VAS_HVWC_SIZE.
+ * uwc = uwc_map + winid * VAS_UWC_SIZE.
+ *
+ * where winid is the window index (0..64K).
+ *
+ * As mentioned, a window context is used to "configure" a window. Besides
+ * this configuration address, each _send_ window also has a unique hardware
+ * "paste" address that is used to submit requests/CRBs (see vas_paste_crb()).
+ *
+ * The hardware paste address for a window is computed using the "paste
+ * base address" and "paste win id shift" reg properties in the VAS device
+ * tree node using:
+ *
+ * paste_addr = paste_base + ((winid << paste_win_id_shift))
+ *
+ * (again, see vas_probe() for ->paste_base_addr and ->paste_win_id_shift).
+ *
+ * The kernel maps this hardware address into the sender's address space
+ * after which they can use the 'paste' instruction (new in Power9) to
+ * send a message (submit a request aka CRB) to the coprocessor.
+ *
+ * NOTE: In the initial version, senders can only in-kernel drivers/threads.
+ * Support for user space threads will be added in follow-on patches.
+ *
+ * TODO: Do we need to map the UWC into user address space so they can return
+ * credits? Its NA for NX but may be needed for other receive windows.
+ *
+ */
+
+#define VAS_WINDOWS_PER_CHIP (64 << 10)
+
+/*
+ * Hypervisor and OS/USer Window Context sizes
+ */
+#define VAS_HVWC_SIZE 512
+#define VAS_UWC_SIZE PAGE_SIZE
+
+/*
+ * Initial per-process credits.
+ * Max send window credits: 4K-1 (12-bits in VAS_TX_WCRED)
+ * Max receive window credits: 64K-1 (16 bits in VAS_LRX_WCRED)
+ *
+ * TODO: Needs tuning for per-process credits
+ */
+#define VAS_WCREDS_MIN 16
+#define VAS_WCREDS_MAX ((64 << 10) - 1)
+#define VAS_WCREDS_DEFAULT (1 << 10)
+
+/*
+ * VAS Window Context Register Offsets and bitmasks.
+ * See Section 3.1.4 of VAS Work book
+ */
+#define VAS_LPID_OFFSET 0x010
+#define VAS_LPID PPC_BITMASK(0, 11)
+
+#define VAS_PID_OFFSET 0x018
+#define VAS_PID_ID PPC_BITMASK(0, 19)
+
+#define VAS_XLATE_MSR_OFFSET 0x020
+#define VAS_XLATE_MSR_DR PPC_BIT(0)
+#define VAS_XLATE_MSR_TA PPC_BIT(1)
+#define VAS_XLATE_MSR_PR PPC_BIT(2)
+#define VAS_XLATE_MSR_US PPC_BIT(3)
+#define VAS_XLATE_MSR_HV PPC_BIT(4)
+#define VAS_XLATE_MSR_SF PPC_BIT(5)
+
+#define VAS_XLATE_LPCR_OFFSET 0x028
+#define VAS_XLATE_LPCR_PAGE_SIZE PPC_BITMASK(0, 2)
+#define VAS_XLATE_LPCR_ISL PPC_BIT(3)
+#define VAS_XLATE_LPCR_TC PPC_BIT(4)
+#define VAS_XLATE_LPCR_SC PPC_BIT(5)
+
+#define VAS_XLATE_CTL_OFFSET 0x030
+#define VAS_XLATE_MODE PPC_BITMASK(0, 1)
+
+#define VAS_AMR_OFFSET 0x040
+#define VAS_AMR PPC_BITMASK(0, 63)
+
+#define VAS_SEIDR_OFFSET 0x048
+#define VAS_SEIDR PPC_BITMASK(0, 63)
+
+#define VAS_FAULT_TX_WIN_OFFSET 0x050
+#define VAS_FAULT_TX_WIN PPC_BITMASK(48, 63)
+
+#define VAS_OSU_INTR_SRC_RA_OFFSET 0x060
+#define VAS_OSU_INTR_SRC_RA PPC_BITMASK(8, 63)
+
+#define VAS_HV_INTR_SRC_RA_OFFSET 0x070
+#define VAS_HV_INTR_SRC_RA PPC_BITMASK(8, 63)
+
+#define VAS_PSWID_OFFSET 0x078
+#define VAS_PSWID_EA_HANDLE PPC_BITMASK(0, 31)
+
+#define VAS_SPARE1_OFFSET 0x080
+#define VAS_SPARE2_OFFSET 0x088
+#define VAS_SPARE3_OFFSET 0x090
+#define VAS_SPARE4_OFFSET 0x130
+#define VAS_SPARE5_OFFSET 0x160
+#define VAS_SPARE6_OFFSET 0x188
+
+#define VAS_LFIFO_BAR_OFFSET 0x0A0
+#define VAS_LFIFO_BAR PPC_BITMASK(8, 53)
+#define VAS_PAGE_MIGRATION_SELECT PPC_BITMASK(54, 56)
+
+#define VAS_LDATA_STAMP_CTL_OFFSET 0x0A8
+#define VAS_LDATA_STAMP PPC_BITMASK(0, 1)
+#define VAS_XTRA_WRITE PPC_BIT(2)
+
+#define VAS_LDMA_CACHE_CTL_OFFSET 0x0B0
+#define VAS_LDMA_TYPE PPC_BITMASK(0, 1)
+#define VAS_LDMA_FIFO_DISABLE PPC_BIT(2)
+
+#define VAS_LRFIFO_PUSH_OFFSET 0x0B8
+#define VAS_LRFIFO_PUSH PPC_BITMASK(0, 15)
+
+#define VAS_CURR_MSG_COUNT_OFFSET 0x0C0
+#define VAS_CURR_MSG_COUNT PPC_BITMASK(0, 7)
+
+#define VAS_LNOTIFY_AFTER_COUNT_OFFSET 0x0C8
+#define VAS_LNOTIFY_AFTER_COUNT PPC_BITMASK(0, 7)
+
+#define VAS_LRX_WCRED_OFFSET 0x0E0
+#define VAS_LRX_WCRED PPC_BITMASK(0, 15)
+
+#define VAS_LRX_WCRED_ADDER_OFFSET 0x190
+#define VAS_LRX_WCRED_ADDER PPC_BITMASK(0, 15)
+
+#define VAS_TX_WCRED_OFFSET 0x0F0
+#define VAS_TX_WCRED PPC_BITMASK(4, 15)
+
+#define VAS_TX_WCRED_ADDER_OFFSET 0x1A0
+#define VAS_TX_WCRED_ADDER PPC_BITMASK(4, 15)
+
+#define VAS_LFIFO_SIZE_OFFSET 0x100
+#define VAS_LFIFO_SIZE PPC_BITMASK(0, 3)
+
+#define VAS_WINCTL_OFFSET 0x108
+#define VAS_WINCTL_OPEN PPC_BIT(0)
+#define VAS_WINCTL_REJ_NO_CREDIT PPC_BIT(1)
+#define VAS_WINCTL_PIN PPC_BIT(2)
+#define VAS_WINCTL_TX_WCRED_MODE PPC_BIT(3)
+#define VAS_WINCTL_RX_WCRED_MODE PPC_BIT(4)
+#define VAS_WINCTL_TX_WORD_MODE PPC_BIT(5)
+#define VAS_WINCTL_RX_WORD_MODE PPC_BIT(6)
+#define VAS_WINCTL_RSVD_TXBUF PPC_BIT(7)
+#define VAS_WINCTL_THRESH_CTL PPC_BITMASK(8, 9)
+#define VAS_WINCTL_FAULT_WIN PPC_BIT(10)
+#define VAS_WINCTL_NX_WIN PPC_BIT(11)
+
+#define VAS_WIN_STATUS_OFFSET 0x110
+#define VAS_WIN_BUSY PPC_BIT(1)
+
+#define VAS_WIN_CTX_CACHING_CTL_OFFSET 0x118
+#define VAS_CASTOUT_REQ PPC_BIT(0)
+#define VAS_PUSH_TO_MEM PPC_BIT(1)
+#define VAS_WIN_CACHE_STATUS PPC_BIT(4)
+
+#define VAS_TX_RSVD_BUF_COUNT_OFFSET 0x120
+#define VAS_RXVD_BUF_COUNT PPC_BITMASK(58, 63)
+
+#define VAS_LRFIFO_WIN_PTR_OFFSET 0x128
+#define VAS_LRX_WIN_ID PPC_BITMASK(0, 15)
+
+/*
+ * Local Notification Control Register controls what happens in _response_
+ * to a paste command and hence applies only to receive windows.
+ */
+#define VAS_LNOTIFY_CTL_OFFSET 0x138
+#define VAS_NOTIFY_DISABLE PPC_BIT(0)
+#define VAS_INTR_DISABLE PPC_BIT(1)
+#define VAS_NOTIFY_EARLY PPC_BIT(2)
+#define VAS_NOTIFY_OSU_INTR PPC_BIT(3)
+
+#define VAS_LNOTIFY_PID_OFFSET 0x140
+#define VAS_LNOTIFY_PID PPC_BITMASK(0, 19)
+
+#define VAS_LNOTIFY_LPID_OFFSET 0x148
+#define VAS_LNOTIFY_LPID PPC_BITMASK(0, 11)
+
+#define VAS_LNOTIFY_TID_OFFSET 0x150
+#define VAS_LNOTIFY_TID PPC_BITMASK(0, 15)
+
+#define VAS_LNOTIFY_SCOPE_OFFSET 0x158
+#define VAS_LNOTIFY_MIN_SCOPE PPC_BITMASK(0, 1)
+#define VAS_LNOTIFY_MAX_SCOPE PPC_BITMASK(2, 3)
+
+#define VAS_NX_UTIL_OFFSET 0x1B0
+#define VAS_NX_UTIL PPC_BITMASK(0, 63)
+
+/* SE: Side effects */
+#define VAS_NX_UTIL_SE_OFFSET 0x1B8
+#define VAS_NX_UTIL_SE PPC_BITMASK(0, 63)
+
+#define VAS_NX_UTIL_ADDER_OFFSET 0x180
+#define VAS_NX_UTIL_ADDER PPC_BITMASK(32, 63)
+
+/*
+ * Local Notify Scope Control Register. (Receive windows only).
+ */
+enum vas_notify_scope {
+ VAS_SCOPE_LOCAL,
+ VAS_SCOPE_GROUP,
+ VAS_SCOPE_VECTORED_GROUP,
+ VAS_SCOPE_UNUSED,
+};
+
+/*
+ * Local DMA Cache Control Register (Receive windows only).
+ */
+enum vas_dma_type {
+ VAS_DMA_TYPE_INJECT,
+ VAS_DMA_TYPE_WRITE,
+};
+
+/*
+ * Local Notify Scope Control Register. (Receive windows only).
+ * Not applicable to NX receive windows.
+ */
+enum vas_notify_after_count {
+ VAS_NOTIFY_AFTER_256 = 0,
+ VAS_NOTIFY_NONE,
+ VAS_NOTIFY_AFTER_2
+};
+
+/*
+ * One per instance of VAS. Each instance will have a separate set of
+ * receive windows, one per coprocessor type.
+ *
+ * See also function header of set_vinst_win() for details on ->windows[]
+ * and ->rxwin[] tables.
+ */
+struct vas_instance {
+ int vas_id;
+ struct ida ida;
+ struct list_head node;
+ struct platform_device *pdev;
+
+ u64 hvwc_bar_start;
+ u64 uwc_bar_start;
+ u64 paste_base_addr;
+ u64 paste_win_id_shift;
+
+ struct mutex mutex;
+ struct vas_window *rxwin[VAS_COP_TYPE_MAX];
+ struct vas_window *windows[VAS_WINDOWS_PER_CHIP];
+};
+
+/*
+ * In-kernel state a VAS window. One per window.
+ */
+struct vas_window {
+ /* Fields common to send and receive windows */
+ struct vas_instance *vinst;
+ int winid;
+ bool tx_win; /* True if send window */
+ bool nx_win; /* True if NX window */
+ bool user_win; /* True if user space window */
+ void *hvwc_map; /* HV window context */
+ void *uwc_map; /* OS/User window context */
+ pid_t pid; /* Linux process id of owner */
+
+ /* Fields applicable only to send windows */
+ void *paste_kaddr;
+ char *paste_addr_name;
+ struct vas_window *rxwin;
+
+ /* Feilds applicable only to receive windows */
+ enum vas_cop_type cop;
+ atomic_t num_txwins;
+};
+
+/*
+ * Container for the hardware state of a window. One per-window.
+ *
+ * A VAS Window context is a 512-byte area in the hardware that contains
+ * a set of 64-bit registers. Individual bit-fields in these registers
+ * determine the configuration/operation of the hardware. struct vas_winctx
+ * is a container for the register fields in the window context.
+ */
+struct vas_winctx {
+ void *rx_fifo;
+ int rx_fifo_size;
+ int wcreds_max;
+ int rsvd_txbuf_count;
+
+ bool user_win;
+ bool nx_win;
+ bool fault_win;
+ bool rsvd_txbuf_enable;
+ bool pin_win;
+ bool rej_no_credit;
+ bool tx_wcred_mode;
+ bool rx_wcred_mode;
+ bool tx_word_mode;
+ bool rx_word_mode;
+ bool data_stamp;
+ bool xtra_write;
+ bool notify_disable;
+ bool intr_disable;
+ bool fifo_disable;
+ bool notify_early;
+ bool notify_os_intr_reg;
+
+ int lpid;
+ int pidr; /* value from SPRN_PID, not linux pid */
+ int lnotify_lpid;
+ int lnotify_pid;
+ int lnotify_tid;
+ u32 pswid;
+ int rx_win_id;
+ int fault_win_id;
+ int tc_mode;
+
+ u64 irq_port;
+
+ enum vas_dma_type dma_type;
+ enum vas_notify_scope min_scope;
+ enum vas_notify_scope max_scope;
+ enum vas_notify_after_count notify_after_count;
+};
+
+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)
+
+#ifdef vas_debug
+static inline void dump_rx_win_attr(struct vas_rx_win_attr *attr)
+{
+ pr_err("fault %d, notify %d, intr %d early %d\n",
+ attr->fault_win, attr->notify_disable,
+ attr->intr_disable, attr->notify_early);
+
+ pr_err("rx_fifo_size %d, max value %d\n",
+ attr->rx_fifo_size, VAS_RX_FIFO_SIZE_MAX);
+}
+
+static inline void vas_log_write(struct vas_window *win, char *name,
+ void *regptr, u64 val)
+{
+ if (val)
+ pr_err("%swin #%d: %s reg %p, val 0x%016llx\n",
+ win->tx_win ? "Tx" : "Rx", win->winid, name,
+ regptr, val);
+}
+
+#else /* vas_debug */
+
+#define vas_log_write(win, name, reg, val)
+#define dump_rx_win_attr(attr)
+
+#endif /* vas_debug */
+
+static inline void write_uwc_reg(struct vas_window *win, char *name,
+ s32 reg, u64 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,
+ s32 reg, u64 val)
+{
+ void *regptr;
+
+ regptr = win->hvwc_map + reg;
+ vas_log_write(win, name, regptr, val);
+
+ out_be64(regptr, val);
+}
+
+static inline u64 read_hvwc_reg(struct vas_window *win,
+ char *name __maybe_unused, s32 reg)
+{
+ return in_be64(win->hvwc_map+reg);
+}
+
+#ifdef vas_debug
+
+static void print_fifo_msg_count(struct vas_window *txwin)
+{
+ uint64_t read_hvwc_reg(struct vas_window *w, char *n, uint64_t o);
+ pr_devel("Winid %d, Msg count %llu\n", txwin->winid,
+ (uint64_t)read_hvwc_reg(txwin, VREG(LRFIFO_PUSH)));
+}
+#else /* vas_debug */
+
+#define print_fifo_msg_count(window)
+
+#endif /* vas_debug */
+
+#endif /* _VAS_H */