1/* SPDX-License-Identifier: GPL-2.0-only */
2/****************************************************************************
3 * Driver for Solarflare network controllers and boards
4 * Copyright 2005-2006 Fen Systems Ltd.
5 * Copyright 2006-2013 Solarflare Communications Inc.
6 */
7
8#ifndef EFX_IO_H
9#define EFX_IO_H
10
11#include <linux/io.h>
12#include <linux/spinlock.h>
13
14/**************************************************************************
15 *
16 * NIC register I/O
17 *
18 **************************************************************************
19 *
20 * The EF10 architecture exposes very few registers to the host and
21 * most of them are only 32 bits wide.  The only exceptions are the MC
22 * doorbell register pair, which has its own latching, and
23 * TX_DESC_UPD.
24 *
25 * The TX_DESC_UPD DMA descriptor pointer is 128-bits but is a special
26 * case in the BIU to avoid the need for locking in the host:
27 *
28 * - It is write-only.
29 * - The semantics of writing to this register is such that
30 *   replacing the low 96 bits with zero does not affect functionality.
31 * - If the host writes to the last dword address of the register
32 *   (i.e. the high 32 bits) the underlying register will always be
33 *   written.  If the collector and the current write together do not
34 *   provide values for all 128 bits of the register, the low 96 bits
35 *   will be written as zero.
36 */
37
38#if BITS_PER_LONG == 64
39#define EFX_USE_QWORD_IO 1
40#endif
41
42/* Hardware issue requires that only 64-bit naturally aligned writes
43 * are seen by hardware. Its not strictly necessary to restrict to
44 * x86_64 arch, but done for safety since unusual write combining behaviour
45 * can break PIO.
46 */
47#ifdef CONFIG_X86_64
48/* PIO is a win only if write-combining is possible */
49#ifdef ioremap_wc
50#define EFX_USE_PIO 1
51#endif
52#endif
53
54static inline u32 efx_reg(struct efx_nic *efx, unsigned int reg)
55{
56	return efx->reg_base + reg;
57}
58
59#ifdef EFX_USE_QWORD_IO
60static inline void _efx_writeq(struct efx_nic *efx, __le64 value,
61				  unsigned int reg)
62{
63	__raw_writeq((__force u64)value, efx->membase + reg);
64}
65static inline __le64 _efx_readq(struct efx_nic *efx, unsigned int reg)
66{
67	return (__force __le64)__raw_readq(efx->membase + reg);
68}
69#endif
70
71static inline void _efx_writed(struct efx_nic *efx, __le32 value,
72				  unsigned int reg)
73{
74	__raw_writel((__force u32)value, efx->membase + reg);
75}
76static inline __le32 _efx_readd(struct efx_nic *efx, unsigned int reg)
77{
78	return (__force __le32)__raw_readl(efx->membase + reg);
79}
80
81/* Write a normal 128-bit CSR, locking as appropriate. */
82static inline void efx_writeo(struct efx_nic *efx, const efx_oword_t *value,
83			      unsigned int reg)
84{
85	unsigned long flags __attribute__ ((unused));
86
87	netif_vdbg(efx, hw, efx->net_dev,
88		   "writing register %x with " EFX_OWORD_FMT "\n", reg,
89		   EFX_OWORD_VAL(*value));
90
91	spin_lock_irqsave(&efx->biu_lock, flags);
92#ifdef EFX_USE_QWORD_IO
93	_efx_writeq(efx, value->u64[0], reg + 0);
94	_efx_writeq(efx, value->u64[1], reg + 8);
95#else
96	_efx_writed(efx, value->u32[0], reg + 0);
97	_efx_writed(efx, value->u32[1], reg + 4);
98	_efx_writed(efx, value->u32[2], reg + 8);
99	_efx_writed(efx, value->u32[3], reg + 12);
100#endif
101	spin_unlock_irqrestore(&efx->biu_lock, flags);
102}
103
104/* Write a 32-bit CSR or the last dword of a special 128-bit CSR */
105static inline void efx_writed(struct efx_nic *efx, const efx_dword_t *value,
106			      unsigned int reg)
107{
108	netif_vdbg(efx, hw, efx->net_dev,
109		   "writing register %x with "EFX_DWORD_FMT"\n",
110		   reg, EFX_DWORD_VAL(*value));
111
112	/* No lock required */
113	_efx_writed(efx, value->u32[0], reg);
114}
115
116/* Read a 128-bit CSR, locking as appropriate. */
117static inline void efx_reado(struct efx_nic *efx, efx_oword_t *value,
118			     unsigned int reg)
119{
120	unsigned long flags __attribute__ ((unused));
121
122	spin_lock_irqsave(&efx->biu_lock, flags);
123	value->u32[0] = _efx_readd(efx, reg + 0);
124	value->u32[1] = _efx_readd(efx, reg + 4);
125	value->u32[2] = _efx_readd(efx, reg + 8);
126	value->u32[3] = _efx_readd(efx, reg + 12);
127	spin_unlock_irqrestore(&efx->biu_lock, flags);
128
129	netif_vdbg(efx, hw, efx->net_dev,
130		   "read from register %x, got " EFX_OWORD_FMT "\n", reg,
131		   EFX_OWORD_VAL(*value));
132}
133
134/* Read a 32-bit CSR or SRAM */
135static inline void efx_readd(struct efx_nic *efx, efx_dword_t *value,
136				unsigned int reg)
137{
138	value->u32[0] = _efx_readd(efx, reg);
139	netif_vdbg(efx, hw, efx->net_dev,
140		   "read from register %x, got "EFX_DWORD_FMT"\n",
141		   reg, EFX_DWORD_VAL(*value));
142}
143
144/* Write a 128-bit CSR forming part of a table */
145static inline void
146efx_writeo_table(struct efx_nic *efx, const efx_oword_t *value,
147		 unsigned int reg, unsigned int index)
148{
149	efx_writeo(efx, value, reg + index * sizeof(efx_oword_t));
150}
151
152/* Read a 128-bit CSR forming part of a table */
153static inline void efx_reado_table(struct efx_nic *efx, efx_oword_t *value,
154				     unsigned int reg, unsigned int index)
155{
156	efx_reado(efx, value, reg + index * sizeof(efx_oword_t));
157}
158
159/* default VI stride (step between per-VI registers) is 8K on EF10 and
160 * 64K on EF100
161 */
162#define EFX_DEFAULT_VI_STRIDE		0x2000
163#define EF100_DEFAULT_VI_STRIDE		0x10000
164
165/* Calculate offset to page-mapped register */
166static inline unsigned int efx_paged_reg(struct efx_nic *efx, unsigned int page,
167					 unsigned int reg)
168{
169	return page * efx->vi_stride + reg;
170}
171
172/* Write the whole of RX_DESC_UPD or TX_DESC_UPD */
173static inline void _efx_writeo_page(struct efx_nic *efx, efx_oword_t *value,
174				    unsigned int reg, unsigned int page)
175{
176	reg = efx_paged_reg(efx, page, reg);
177
178	netif_vdbg(efx, hw, efx->net_dev,
179		   "writing register %x with " EFX_OWORD_FMT "\n", reg,
180		   EFX_OWORD_VAL(*value));
181
182#ifdef EFX_USE_QWORD_IO
183	_efx_writeq(efx, value->u64[0], reg + 0);
184	_efx_writeq(efx, value->u64[1], reg + 8);
185#else
186	_efx_writed(efx, value->u32[0], reg + 0);
187	_efx_writed(efx, value->u32[1], reg + 4);
188	_efx_writed(efx, value->u32[2], reg + 8);
189	_efx_writed(efx, value->u32[3], reg + 12);
190#endif
191}
192#define efx_writeo_page(efx, value, reg, page)				\
193	_efx_writeo_page(efx, value,					\
194			 reg +						\
195			 BUILD_BUG_ON_ZERO((reg) != 0x830 && (reg) != 0xa10), \
196			 page)
197
198/* Write a page-mapped 32-bit CSR (EVQ_RPTR, EVQ_TMR (EF10), or the
199 * high bits of RX_DESC_UPD or TX_DESC_UPD)
200 */
201static inline void
202_efx_writed_page(struct efx_nic *efx, const efx_dword_t *value,
203		 unsigned int reg, unsigned int page)
204{
205	efx_writed(efx, value, efx_paged_reg(efx, page, reg));
206}
207#define efx_writed_page(efx, value, reg, page)				\
208	_efx_writed_page(efx, value,					\
209			 reg +						\
210			 BUILD_BUG_ON_ZERO((reg) != 0x180 &&		\
211					   (reg) != 0x200 &&		\
212					   (reg) != 0x400 &&		\
213					   (reg) != 0x420 &&		\
214					   (reg) != 0x830 &&		\
215					   (reg) != 0x83c &&		\
216					   (reg) != 0xa18 &&		\
217					   (reg) != 0xa1c),		\
218			 page)
219
220/* Write TIMER_COMMAND.  This is a page-mapped 32-bit CSR, but a bug
221 * in the BIU means that writes to TIMER_COMMAND[0] invalidate the
222 * collector register.
223 */
224static inline void _efx_writed_page_locked(struct efx_nic *efx,
225					   const efx_dword_t *value,
226					   unsigned int reg,
227					   unsigned int page)
228{
229	unsigned long flags __attribute__ ((unused));
230
231	if (page == 0) {
232		spin_lock_irqsave(&efx->biu_lock, flags);
233		efx_writed(efx, value, efx_paged_reg(efx, page, reg));
234		spin_unlock_irqrestore(&efx->biu_lock, flags);
235	} else {
236		efx_writed(efx, value, efx_paged_reg(efx, page, reg));
237	}
238}
239#define efx_writed_page_locked(efx, value, reg, page)			\
240	_efx_writed_page_locked(efx, value,				\
241				reg + BUILD_BUG_ON_ZERO((reg) != 0x420), \
242				page)
243
244#endif /* EFX_IO_H */
245