[PATCH v4 02/11] VAS: Define macros, register fields and structures

Sukadev Bhattiprolu
2017-03-31T05:14:11Z

Define macros for the VAS hardware registers and bit-fields as well
as couple of data structures needed by the VAS driver.

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
---
Changelog[v4]
- [Michael Neuling] Move VAS code to arch/powerpc; Reorg vas.h and
vas-internal.h to kernel and uapi versions; rather than creating
separate properties for window context/address entries in device
tree, combine them into "reg" properties; drop ->hwirq and irq_port
fields from vas_window as they are only needed with user space
windows.

Changelog[v3]
- Rename winctx->pid to winctx->pidr to reflect that its a value
from the PID register (SPRN_PID), not the linux process id.
- Make it easier to split header into kernel/user parts
- To keep user interface simple, use macros rather than enum for
the threshold-control modes.
- Add a pid field to struct vas_window - needed for user space
send windows.

Changelog[v2]
- Add an overview of VAS in vas-internal.h
- Get window context parameters from device tree and drop
unnecessary macros.
---
arch/powerpc/include/asm/vas.h | 34 +++
arch/powerpc/include/uapi/asm/vas.h | 25 +++
arch/powerpc/platforms/powernv/vas.h | 387 +++++++++++++++++++++++++++++++++++
3 files changed, 446 insertions(+)
create mode 100644 arch/powerpc/include/asm/vas.h
create mode 100644 arch/powerpc/include/uapi/asm/vas.h
create mode 100644 arch/powerpc/platforms/powernv/vas.h

diff --git a/arch/powerpc/include/asm/vas.h b/arch/powerpc/include/asm/vas.h
new file mode 100644
index 0000000..e2575d5
--- /dev/null
+++ b/arch/powerpc/include/asm/vas.h
@@ -0,0 +1,34 @@
+/*
+ * Copyright 2016 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 _MISC_VAS_H
+#define _MISC_VAS_H
+
+#include <uapi/asm/vas.h>
+
+/*
+ * Min and max FIFO sizes are based on Version 1.05 Section 3.1.4.25
+ * (Local FIFO Size Register) of the VAS workbook.
+ */
+#define VAS_RX_FIFO_SIZE_MIN (1 << 10) /* 1KB */
+#define VAS_RX_FIFO_SIZE_MAX (8 << 20) /* 8MB */
+
+/*
+ * Co-processor Engine type.
+ */
+enum vas_cop_type {
+ VAS_COP_TYPE_FAULT,
+ VAS_COP_TYPE_842,
+ VAS_COP_TYPE_842_HIPRI,
+ VAS_COP_TYPE_GZIP,
+ VAS_COP_TYPE_GZIP_HIPRI,
+ VAS_COP_TYPE_MAX,
+};
+
+#endif /* _MISC_VAS_H */
diff --git a/arch/powerpc/include/uapi/asm/vas.h b/arch/powerpc/include/uapi/asm/vas.h
new file mode 100644
index 0000000..ddfe046
--- /dev/null
+++ b/arch/powerpc/include/uapi/asm/vas.h
@@ -0,0 +1,25 @@
+/*
+ * Copyright 2016 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 _UAPI_MISC_VAS_H
+#define _UAPI_MISC_VAS_H
+
+/*
+ * Threshold Control Mode: Have paste operation fail if the number of
+ * requests in receive FIFO exceeds a threshold.
+ *
+ * NOTE: No special error code yet if paste is rejected because of these
+ * limits. So users can't distinguish between this and other errors.
+ */
+#define VAS_THRESH_DISABLED 0
+#define VAS_THRESH_FIFO_GT_HALF_FULL 1
+#define VAS_THRESH_FIFO_GT_QTR_FULL 2
+#define VAS_THRESH_FIFO_GT_EIGHTH_FULL 3
+
+#endif /* _UAPI_MISC_VAS_H */
diff --git a/arch/powerpc/platforms/powernv/vas.h b/arch/powerpc/platforms/powernv/vas.h
new file mode 100644
index 0000000..c63395d
--- /dev/null
+++ b/arch/powerpc/platforms/powernv/vas.h
@@ -0,0 +1,387 @@
+/*
+ * Copyright 2016 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>
+
+#ifdef CONFIG_PPC_4K_PAGES
+# error "TODO: Compute RMA/Paste-address for 4K pages."
+#else
+#ifndef CONFIG_PPC_64K_PAGES
+# error "Unexpected Page size."
+#endif
+#endif
+
+/*
+ * 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 the device tree in the first four of six 64-bit entries in:
+ *
+ * /proc/device-tree/xscom@.../vas@.../reg
+ *
+ * where
+ *
+ * [0], [1] HVWC BAR start and size
+ * [2], [3] UWC BAR start and size
+ * [4], [5] "Window base" and "Window shift"
+ *
+ * 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 (or CRBs).
+ *
+ * The hardware paste address for a window is computed using the "Window
+ * base" (base) and "Window shift" (shift) values ("reg" properties [4]
+ * and [5]), as follows:
+ *
+ * paste_addr = base + ((winid << 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).
+ *
+ * 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.
+ *
+ */
+
+/* TODO: Increase to 64K after initial development */
+#define VAS_MAX_WINDOWS_PER_CHIP 64
+
+/*
+ * 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_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.
+ */
+struct vas_instance {
+ int vas_id;
+ struct ida ida;
+
+ u64 hvwc_bar_start;
+ u64 hvwc_bar_len;
+ u64 uwc_bar_start;
+ u64 uwc_bar_len;
+ u64 win_base_addr;
+ u64 win_id_shift;
+
+ struct mutex mutex;
+ struct vas_window *rxwin[VAS_COP_TYPE_MAX];
+};
+
+/*
+ * 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 */
+ void *hvwc_map; /* HV window context */
+ void *uwc_map; /* OS/User window context */
+
+ /* Fields applicable only to send windows */
+ pid_t pid; /* linux process id of sender, if applicable */
+ 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 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;
+ int pswid;
+ int rx_win_id;
+ int fault_win_id;
+ int tc_mode;
+
+ uint64_t 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;
+};
+
+#endif /* _VAS_H */
--
2.7.4