[PATCH] spufs: switchable spu contexts

Add some infrastructure for saving and restoring the context of an
SPE. This patch creates a new structure that can hold the whole
state of a physical SPE in memory. It also contains code that
avoids races during the context switch and the binary code that
is loaded to the SPU in order to access its registers.

The actual PPE- and SPE-side context switch code are two separate
patches.

Signed-off-by: Arnd Bergmann <arndb@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 256 insertions, 0 deletions

diff --git a/include/asm-powerpc/spu_csa.h b/include/asm-powerpc/spu_csa.h
new file mode 100644
index 000000000000..d1d537de4f5c
--- /dev/null
+++ b/include/asm-powerpc/spu_csa.h
@@ -0,0 +1,256 @@
+/*
+ * spu_csa.h: Definitions for SPU context save area (CSA).
+ *
+ * (C) Copyright IBM 2005
+ *
+ * Author: Mark Nutter <mnutter@us.ibm.com>
+ *
+ * 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, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#ifndef _SPU_CSA_H_
+#define _SPU_CSA_H_
+
+/*
+ * Total number of 128-bit registers.
+ */
+#define NR_SPU_GPRS             128
+#define NR_SPU_SPRS             9
+#define NR_SPU_REGS_PAD         7
+#define NR_SPU_SPILL_REGS       144     /* GPRS + SPRS + PAD */
+#define SIZEOF_SPU_SPILL_REGS   NR_SPU_SPILL_REGS * 16
+
+#define SPU_SAVE_COMPLETE       0x3FFB
+#define SPU_RESTORE_COMPLETE    0x3FFC
+
+/*
+ * Definitions for various 'stopped' status conditions,
+ * to be recreated during context restore.
+ */
+#define SPU_STOPPED_STATUS_P    1
+#define SPU_STOPPED_STATUS_I    2
+#define SPU_STOPPED_STATUS_H    3
+#define SPU_STOPPED_STATUS_S    4
+#define SPU_STOPPED_STATUS_S_I  5
+#define SPU_STOPPED_STATUS_S_P  6
+#define SPU_STOPPED_STATUS_P_H  7
+#define SPU_STOPPED_STATUS_P_I  8
+#define SPU_STOPPED_STATUS_R    9
+
+#ifndef  __ASSEMBLY__
+/**
+ * spu_reg128 - generic 128-bit register definition.
+ */
+struct spu_reg128 {
+        u32 slot[4];
+};
+
+/**
+ * struct spu_lscsa - Local Store Context Save Area.
+ * @gprs: Array of saved registers.
+ * @fpcr: Saved floating point status control register.
+ * @decr: Saved decrementer value.
+ * @decr_status: Indicates decrementer run status.
+ * @ppu_mb: Saved PPU mailbox data.
+ * @ppuint_mb: Saved PPU interrupting mailbox data.
+ * @tag_mask: Saved tag group mask.
+ * @event_mask: Saved event mask.
+ * @srr0: Saved SRR0.
+ * @stopped_status: Conditions to be recreated by restore.
+ * @ls: Saved contents of Local Storage Area.
+ *
+ * The LSCSA represents state that is primarily saved and
+ * restored by SPU-side code.
+ */
+struct spu_lscsa {
+        struct spu_reg128 gprs[128];
+        struct spu_reg128 fpcr;
+        struct spu_reg128 decr;
+        struct spu_reg128 decr_status;
+        struct spu_reg128 ppu_mb;
+        struct spu_reg128 ppuint_mb;
+        struct spu_reg128 tag_mask;
+        struct spu_reg128 event_mask;
+        struct spu_reg128 srr0;
+        struct spu_reg128 stopped_status;
+        struct spu_reg128 pad[119];     /* 'ls' must be page-aligned. */
+        unsigned char ls[LS_SIZE];
+};
+
+#ifdef __KERNEL__
+
+/*
+ * struct spu_problem_collapsed - condensed problem state area, w/o pads.
+ */
+struct spu_problem_collapsed {
+        u64 spc_mssync_RW;
+        u32 mfc_lsa_W;
+        u32 unused_pad0;
+        u64 mfc_ea_W;
+        union mfc_tag_size_class_cmd mfc_union_W;
+        u32 dma_qstatus_R;
+        u32 dma_querytype_RW;
+        u32 dma_querymask_RW;
+        u32 dma_tagstatus_R;
+        u32 pu_mb_R;
+        u32 spu_mb_W;
+        u32 mb_stat_R;
+        u32 spu_runcntl_RW;
+        u32 spu_status_R;
+        u32 spu_spc_R;
+        u32 spu_npc_RW;
+        u32 signal_notify1;
+        u32 signal_notify2;
+        u32 unused_pad1;
+};
+
+/*
+ * struct spu_priv1_collapsed - condensed privileged 1 area, w/o pads.
+ */
+struct spu_priv1_collapsed {
+        u64 mfc_sr1_RW;
+        u64 mfc_lpid_RW;
+        u64 spu_idr_RW;
+        u64 mfc_vr_RO;
+        u64 spu_vr_RO;
+        u64 int_mask_class0_RW;
+        u64 int_mask_class1_RW;
+        u64 int_mask_class2_RW;
+        u64 int_stat_class0_RW;
+        u64 int_stat_class1_RW;
+        u64 int_stat_class2_RW;
+        u64 int_route_RW;
+        u64 mfc_atomic_flush_RW;
+        u64 resource_allocation_groupID_RW;
+        u64 resource_allocation_enable_RW;
+        u64 mfc_fir_R;
+        u64 mfc_fir_status_or_W;
+        u64 mfc_fir_status_and_W;
+        u64 mfc_fir_mask_R;
+        u64 mfc_fir_mask_or_W;
+        u64 mfc_fir_mask_and_W;
+        u64 mfc_fir_chkstp_enable_RW;
+        u64 smf_sbi_signal_sel;
+        u64 smf_ato_signal_sel;
+        u64 mfc_sdr_RW;
+        u64 tlb_index_hint_RO;
+        u64 tlb_index_W;
+        u64 tlb_vpn_RW;
+        u64 tlb_rpn_RW;
+        u64 tlb_invalidate_entry_W;
+        u64 tlb_invalidate_all_W;
+        u64 smm_hid;
+        u64 mfc_accr_RW;
+        u64 mfc_dsisr_RW;
+        u64 mfc_dar_RW;
+        u64 rmt_index_RW;
+        u64 rmt_data1_RW;
+        u64 mfc_dsir_R;
+        u64 mfc_lsacr_RW;
+        u64 mfc_lscrr_R;
+        u64 mfc_tclass_id_RW;
+        u64 mfc_rm_boundary;
+        u64 smf_dma_signal_sel;
+        u64 smm_signal_sel;
+        u64 mfc_cer_R;
+        u64 pu_ecc_cntl_RW;
+        u64 pu_ecc_stat_RW;
+        u64 spu_ecc_addr_RW;
+        u64 spu_err_mask_RW;
+        u64 spu_trig0_sel;
+        u64 spu_trig1_sel;
+        u64 spu_trig2_sel;
+        u64 spu_trig3_sel;
+        u64 spu_trace_sel;
+        u64 spu_event0_sel;
+        u64 spu_event1_sel;
+        u64 spu_event2_sel;
+        u64 spu_event3_sel;
+        u64 spu_trace_cntl;
+};
+
+/*
+ * struct spu_priv2_collapsed - condensed priviliged 2 area, w/o pads.
+ */
+struct spu_priv2_collapsed {
+        u64 slb_index_W;
+        u64 slb_esid_RW;
+        u64 slb_vsid_RW;
+        u64 slb_invalidate_entry_W;
+        u64 slb_invalidate_all_W;
+        struct mfc_cq_sr spuq[16];
+        struct mfc_cq_sr puq[8];
+        u64 mfc_control_RW;
+        u64 puint_mb_R;
+        u64 spu_privcntl_RW;
+        u64 spu_lslr_RW;
+        u64 spu_chnlcntptr_RW;
+        u64 spu_chnlcnt_RW;
+        u64 spu_chnldata_RW;
+        u64 spu_cfg_RW;
+        u64 spu_pm_trace_tag_status_RW;
+        u64 spu_tag_status_query_RW;
+        u64 spu_cmd_buf1_RW;
+        u64 spu_cmd_buf2_RW;
+        u64 spu_atomic_status_RW;
+};
+
+/**
+ * struct spu_state
+ * @lscsa: Local Store Context Save Area.
+ * @prob: Collapsed Problem State Area, w/o pads.
+ * @priv1: Collapsed Privileged 1 Area, w/o pads.
+ * @priv2: Collapsed Privileged 2 Area, w/o pads.
+ * @spu_chnlcnt_RW: Array of saved channel counts.
+ * @spu_chnldata_RW: Array of saved channel data.
+ * @suspend_time: Time stamp when decrementer disabled.
+ * @slb_esid_RW: Array of saved SLB esid entries.
+ * @slb_vsid_RW: Array of saved SLB vsid entries.
+ *
+ * Structure representing the whole of the SPU
+ * context save area (CSA).  This struct contains
+ * all of the state necessary to suspend and then
+ * later optionally resume execution of an SPU
+ * context.
+ *
+ * The @lscsa region is by far the largest, and is
+ * allocated separately so that it may either be
+ * pinned or mapped to/from application memory, as
+ * appropriate for the OS environment.
+ */
+struct spu_state {
+        struct spu_lscsa *lscsa;
+        struct spu_problem_collapsed prob;
+        struct spu_priv1_collapsed priv1;
+        struct spu_priv2_collapsed priv2;
+        u64 spu_chnlcnt_RW[32];
+        u64 spu_chnldata_RW[32];
+        u32 spu_mailbox_data[4];
+        u32 pu_mailbox_data[1];
+        unsigned long suspend_time;
+        u64 slb_esid_RW[8];
+        u64 slb_vsid_RW[8];
+};
+
+extern void spu_init_csa(struct spu_state *csa);
+extern void spu_fini_csa(struct spu_state *csa);
+extern int spu_save(struct spu_state *prev, struct spu *spu);
+extern int spu_restore(struct spu_state *new, struct spu *spu);
+extern int spu_switch(struct spu_state *prev, struct spu_state *new,
+                      struct spu *spu);
+
+#endif /* __KERNEL__ */
+#endif /* !__ASSEMBLY__ */
+#endif /* _SPU_CSA_H_ */