419e27f32b
Introduce a set of APIs for retrieving and updating PAPR system parameters. This encapsulates the toil of temporary RTAS work area management, RTAS function call retries, and translation of RTAS call statuses to conventional error values. There are several places in the kernel that already retrieve system parameters by calling the RTAS ibm,get-system-parameter function directly. These will be converted to papr_sysparm_get() in changes to follow. As for updating system parameters, current practice is to use sys_rtas() from user space; there are no in-kernel users of the RTAS ibm,set-system-parameter function. However this will become deprecated in time because it is not compatible with lockdown. The papr_sysparm_* APIs will form the common basis for in-kernel and user space access to system parameters. The code to expose the set/get capabilities to user space will follow. Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20230125-b4-powerpc-rtas-queue-v3-14-26929c8cce78@linux.ibm.com
39 lines
1.2 KiB
C
39 lines
1.2 KiB
C
/* SPDX-License-Identifier: GPL-2.0-only */
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#ifndef _ASM_POWERPC_PAPR_SYSPARM_H
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#define _ASM_POWERPC_PAPR_SYSPARM_H
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typedef struct {
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const u32 token;
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} papr_sysparm_t;
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#define mk_papr_sysparm(x_) ((papr_sysparm_t){ .token = x_, })
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/*
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* Derived from the "Defined Parameters" table in PAPR 7.3.16 System
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* Parameters Option. Where the spec says "characteristics", we use
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* "attrs" in the symbolic names to keep them from getting too
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* unwieldy.
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*/
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#define PAPR_SYSPARM_SHARED_PROC_LPAR_ATTRS mk_papr_sysparm(20)
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#define PAPR_SYSPARM_PROC_MODULE_INFO mk_papr_sysparm(43)
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#define PAPR_SYSPARM_COOP_MEM_OVERCOMMIT_ATTRS mk_papr_sysparm(44)
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#define PAPR_SYSPARM_TLB_BLOCK_INVALIDATE_ATTRS mk_papr_sysparm(50)
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#define PAPR_SYSPARM_LPAR_NAME mk_papr_sysparm(55)
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enum {
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PAPR_SYSPARM_MAX_INPUT = 1024,
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PAPR_SYSPARM_MAX_OUTPUT = 4000,
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};
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struct papr_sysparm_buf {
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__be16 len;
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char val[PAPR_SYSPARM_MAX_OUTPUT];
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};
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struct papr_sysparm_buf *papr_sysparm_buf_alloc(void);
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void papr_sysparm_buf_free(struct papr_sysparm_buf *buf);
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int papr_sysparm_set(papr_sysparm_t param, const struct papr_sysparm_buf *buf);
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int papr_sysparm_get(papr_sysparm_t param, struct papr_sysparm_buf *buf);
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#endif /* _ASM_POWERPC_PAPR_SYSPARM_H */
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