linux/arch/powerpc/include/asm/drmem.h
Laurent Dufour d144f4d5a8 pseries/drmem: update LMBs after LPM
After a LPM, the device tree node ibm,dynamic-reconfiguration-memory may be
updated by the hypervisor in the case the NUMA topology of the LPAR's
memory is updated.

This is handled by the kernel, but the memory's node is not updated because
there is no way to move a memory block between nodes from the Linux kernel
point of view.

If later a memory block is added or removed, drmem_update_dt() is called
and it is overwriting the DT node ibm,dynamic-reconfiguration-memory to
match the added or removed LMB. But the LMB's associativity node has not
been updated after the DT node update and thus the node is overwritten by
the Linux's topology instead of the hypervisor one.

Introduce a hook called when the ibm,dynamic-reconfiguration-memory node is
updated to force an update of the LMB's associativity. However, ignore the
call to that hook when the update has been triggered by drmem_update_dt().
Because, in that case, the LMB tree has been used to set the DT property
and thus it doesn't need to be updated back. Since drmem_update_dt() is
called under the protection of the device_hotplug_lock and the hook is
called in the same context, use a simple boolean variable to detect that
call.

Signed-off-by: Laurent Dufour <ldufour@linux.ibm.com>
Reviewed-by: Nathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210517090606.56930-1-ldufour@linux.ibm.com
2021-08-10 23:14:55 +10:00

123 lines
2.9 KiB
C

/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* drmem.h: Power specific logical memory block representation
*
* Copyright 2017 IBM Corporation
*/
#ifndef _ASM_POWERPC_LMB_H
#define _ASM_POWERPC_LMB_H
#include <linux/sched.h>
struct drmem_lmb {
u64 base_addr;
u32 drc_index;
u32 aa_index;
u32 flags;
};
struct drmem_lmb_info {
struct drmem_lmb *lmbs;
int n_lmbs;
u64 lmb_size;
};
extern struct drmem_lmb_info *drmem_info;
static inline struct drmem_lmb *drmem_lmb_next(struct drmem_lmb *lmb,
const struct drmem_lmb *start)
{
/*
* DLPAR code paths can take several milliseconds per element
* when interacting with firmware. Ensure that we don't
* unfairly monopolize the CPU.
*/
if (((++lmb - start) % 16) == 0)
cond_resched();
return lmb;
}
#define for_each_drmem_lmb_in_range(lmb, start, end) \
for ((lmb) = (start); (lmb) < (end); lmb = drmem_lmb_next(lmb, start))
#define for_each_drmem_lmb(lmb) \
for_each_drmem_lmb_in_range((lmb), \
&drmem_info->lmbs[0], \
&drmem_info->lmbs[drmem_info->n_lmbs])
/*
* The of_drconf_cell_v1 struct defines the layout of the LMB data
* specified in the ibm,dynamic-memory device tree property.
* The property itself is a 32-bit value specifying the number of
* LMBs followed by an array of of_drconf_cell_v1 entries, one
* per LMB.
*/
struct of_drconf_cell_v1 {
__be64 base_addr;
__be32 drc_index;
__be32 reserved;
__be32 aa_index;
__be32 flags;
};
/*
* Version 2 of the ibm,dynamic-memory property is defined as a
* 32-bit value specifying the number of LMB sets followed by an
* array of of_drconf_cell_v2 entries, one per LMB set.
*/
struct of_drconf_cell_v2 {
u32 seq_lmbs;
u64 base_addr;
u32 drc_index;
u32 aa_index;
u32 flags;
} __packed;
#define DRCONF_MEM_ASSIGNED 0x00000008
#define DRCONF_MEM_AI_INVALID 0x00000040
#define DRCONF_MEM_RESERVED 0x00000080
#define DRCONF_MEM_HOTREMOVABLE 0x00000100
static inline u64 drmem_lmb_size(void)
{
return drmem_info->lmb_size;
}
#define DRMEM_LMB_RESERVED 0x80000000
static inline void drmem_mark_lmb_reserved(struct drmem_lmb *lmb)
{
lmb->flags |= DRMEM_LMB_RESERVED;
}
static inline void drmem_remove_lmb_reservation(struct drmem_lmb *lmb)
{
lmb->flags &= ~DRMEM_LMB_RESERVED;
}
static inline bool drmem_lmb_reserved(struct drmem_lmb *lmb)
{
return lmb->flags & DRMEM_LMB_RESERVED;
}
u64 drmem_lmb_memory_max(void);
int walk_drmem_lmbs(struct device_node *dn, void *data,
int (*func)(struct drmem_lmb *, const __be32 **, void *));
int drmem_update_dt(void);
#ifdef CONFIG_PPC_PSERIES
int __init
walk_drmem_lmbs_early(unsigned long node, void *data,
int (*func)(struct drmem_lmb *, const __be32 **, void *));
void drmem_update_lmbs(struct property *prop);
#endif
static inline void invalidate_lmb_associativity_index(struct drmem_lmb *lmb)
{
lmb->aa_index = 0xffffffff;
}
#endif /* _ASM_POWERPC_LMB_H */