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powerpc: Add Initiate Coprocessor Store Word (icswx) support

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Icswx is a PowerPC instruction to send data to a co-processor. On Book-S
processors the LPAR_ID and process ID (PID) of the owning process are
registered in the window context of the co-processor at initialization
time. When the icswx instruction is executed the L2 generates a cop-reg
transaction on PowerBus. The transaction has no address and the
processor does not perform an MMU access to authenticate the transaction.
The co-processor compares the LPAR_ID and the PID included in the
transaction and the LPAR_ID and PID held in the window context to
determine if the process is authorized to generate the transaction.

The OS needs to assign a 16-bit PID for the process. This cop-PID needs
to be updated during context switch. The cop-PID needs to be destroyed
when the context is destroyed.

Signed-off-by: Sonny Rao <sonnyrao@linux.vnet.ibm.com>
Signed-off-by: Tseng-Hui (Frank) Lin <thlin@linux.vnet.ibm.com>
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This commit is contained in:
Tseng-Hui (Frank) Lin
2011-05-02 20:43:04 +00:00
committed by Benjamin Herrenschmidt
parent a32e252f7c
commit 851d2e2fe8
6 changed files with 249 additions and 1 deletions
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6
arch/powerpc/include/asm/mmu-hash64.h
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@@ -408,6 +408,7 @@ static inline void subpage_prot_init_new_context(struct mm_struct *mm) { }
#endif /* CONFIG_PPC_SUBPAGE_PROT */
typedef unsigned long mm_context_id_t;
struct spinlock;
typedef struct {
mm_context_id_t id;
@@ -423,6 +424,11 @@ typedef struct {
#ifdef CONFIG_PPC_SUBPAGE_PROT
struct subpage_prot_table spt;
#endif /* CONFIG_PPC_SUBPAGE_PROT */
#ifdef CONFIG_PPC_ICSWX
struct spinlock *cop_lockp; /* guard acop and cop_pid */
unsigned long acop; /* mask of enabled coprocessor types */
unsigned int cop_pid; /* pid value used with coprocessors */
#endif /* CONFIG_PPC_ICSWX */
} mm_context_t;