linux-stable/arch/powerpc/include/asm/svm.h
Thiago Jung Bauermann eae9eec476 powerpc/pseries/svm: Allocate SWIOTLB buffer anywhere in memory
POWER secure guests (i.e., guests which use the Protected Execution
Facility) need to use SWIOTLB to be able to do I/O with the
hypervisor, but they don't need the SWIOTLB memory to be in low
addresses since the hypervisor doesn't have any addressing limitation.

This solves a SWIOTLB initialization problem we are seeing in secure
guests with 128 GB of RAM: they are configured with 4 GB of
crashkernel reserved memory, which leaves no space for SWIOTLB in low
addresses.

To do this, we use mostly the same code as swiotlb_init(), but
allocate the buffer using memblock_alloc() instead of
memblock_alloc_low().

Fixes: 2efbc58f15 ("powerpc/pseries/svm: Force SWIOTLB for secure guests")
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200818221126.391073-1-bauerman@linux.ibm.com
2020-09-14 23:07:14 +10:00

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C

/* SPDX-License-Identifier: GPL-2.0+ */
/*
* SVM helper functions
*
* Copyright 2018 Anshuman Khandual, IBM Corporation.
*/
#ifndef _ASM_POWERPC_SVM_H
#define _ASM_POWERPC_SVM_H
#ifdef CONFIG_PPC_SVM
static inline bool is_secure_guest(void)
{
return mfmsr() & MSR_S;
}
void __init svm_swiotlb_init(void);
void dtl_cache_ctor(void *addr);
#define get_dtl_cache_ctor() (is_secure_guest() ? dtl_cache_ctor : NULL)
#else /* CONFIG_PPC_SVM */
static inline bool is_secure_guest(void)
{
return false;
}
static inline void svm_swiotlb_init(void) {}
#define get_dtl_cache_ctor() NULL
#endif /* CONFIG_PPC_SVM */
#endif /* _ASM_POWERPC_SVM_H */