[v3,01/10] VAS: Define macros, register fields and structures

Submitted by Sukadev Bhattiprolu on March 17, 2017, 3:33 a.m.

Details

Message ID 1489721642-5657-2-git-send-email-sukadev@linux.vnet.ibm.com
State Needs Review / ACK
Headers show

Commit Message

Sukadev Bhattiprolu March 17, 2017, 3:33 a.m.
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[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.
---
 MAINTAINERS                     |   6 +
 arch/powerpc/include/asm/vas.h  |  43 +++++
 drivers/misc/vas/vas-internal.h | 392 ++++++++++++++++++++++++++++++++++++++++
 3 files changed, 441 insertions(+)
 create mode 100644 arch/powerpc/include/asm/vas.h
 create mode 100644 drivers/misc/vas/vas-internal.h

Patch hide | download patch | download mbox

diff --git a/MAINTAINERS b/MAINTAINERS
index c265a5f..2a910c9 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -13213,6 +13213,12 @@  S:	Maintained
 F:	Documentation/fb/uvesafb.txt
 F:	drivers/video/fbdev/uvesafb.*
 
+VAS (IBM Virtual Accelerator Switchboard) DRIVER
+M:	Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
+L:	linuxppc-dev@lists.ozlabs.org
+S:	Supported
+F:	drivers/misc/vas/*
+
 VF610 NAND DRIVER
 M:	Stefan Agner <stefan@agner.ch>
 L:	linux-mtd@lists.infradead.org
diff --git a/arch/powerpc/include/asm/vas.h b/arch/powerpc/include/asm/vas.h
new file mode 100644
index 0000000..6d35ce6
--- /dev/null
+++ b/arch/powerpc/include/asm/vas.h
@@ -0,0 +1,43 @@ 
+/*
+ * 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
+
+/*
+ * 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
+
+#ifdef __KERNEL__
+
+#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	/* __KERNEL__ */
+
+#endif
diff --git a/drivers/misc/vas/vas-internal.h b/drivers/misc/vas/vas-internal.h
new file mode 100644
index 0000000..ce48f14
--- /dev/null
+++ b/drivers/misc/vas/vas-internal.h
@@ -0,0 +1,392 @@ 
+/*
+ * 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_INTERNAL_H
+#define VAS_INTERNAL_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 instructions
+ * "copy" and "paste" 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 as follows:
+ *
+ *	/proc/device-tree/xscom@.../vas@.../hvwc-bar-start
+ *	/proc/device-tree/xscom@.../vas@.../hvwc-bar-size
+ *	/proc/device-tree/xscom@.../vas@.../uwc-bar-start
+ *	/proc/device-tree/xscom@.../vas@.../uwc-bar-size
+ *
+ * The kernel maps these two hardware address regions into the kernel address
+ * space (hvwc_map and uwc_map) and accesses 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).
+ *
+ * Note that the window contexts are used to "configure" the windows. In
+ * addition to this configuration address, each _send_ window also has a
+ * unique hardware address, referred to as the "paste-address" to which the
+ * sender must "paste" the message (CRB) they wish to submit. This hardware
+ * paste address for window can be computed from the following nodes in the
+ * device tree:
+ *
+ *	/proc/device-tree/xscom@.../vas@.../window-base
+ *	/proc/device-tree/xscom@.../vas@.../window-shift
+ *
+ * Thus if 'base' and 'shift' give the values of the above nodes for a given
+ * instance of VAS, the paste address for a window can be computed using:
+ *
+ *	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 to send a message (submit a
+ * request).
+ *
+ * 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_MSR_UV		PPC_BIT(6)
+
+#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 data structure for 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;
+
+	int32_t hwirq;
+	uint64_t irq_port;
+};
+
+/*
+ * 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.
+ * One per window.
+ */
+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