Commit e9eb0278 authored by Michael Ellerman's avatar Michael Ellerman
Browse files

powerpc/64: Used named initialisers for ibm_pa_features 



The ibm_pa_features array consists of structures that describe which bit
and byte in the ibm,pa-features property toggles one or more flags in
either the CPU, MMU, or user visible feature flags.

Each one consists of 7 values, which are all unsigned long, int or char,
meaning the compiler gives us no warning if we assign the wrong values
to the wrong elements. In fact we have had a bug here in the past, where
we were setting incorrect bits, see commit 6997e57d ("powerpc:
scan_features() updates incorrect bits for REAL_LE").

So switch to using named initialisers for the structure elements, to
reduce the likelihood of future bugs, and hopefully improve readability
also.

Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Reviewed-by: default avatarBalbir Singh <bsingharora@gmail.com>
parent 3baad970

arch/powerpc/kernel/prom.c

+11 −10
Original line number Diff line number Diff line
@@ -156,21 +156,22 @@ static struct ibm_pa_feature { 
	unsigned char	pabit;		/* bit number (big-endian) */

	unsigned char	invert;		/* if 1, pa bit set => clear feature */

} ibm_pa_features[] __initdata = {

	{0, 0, PPC_FEATURE_HAS_MMU, 0,		0, 0, 0},

	{0, 0, PPC_FEATURE_HAS_FPU, 0,		0, 1, 0},

	{CPU_FTR_CTRL, 0, 0, 0,			0, 3, 0},

	{CPU_FTR_NOEXECUTE, 0, 0, 0,		0, 6, 0},

	{CPU_FTR_NODSISRALIGN, 0, 0, 0,		1, 1, 1},

	{0, MMU_FTR_CI_LARGE_PAGE, 0, 0,		1, 2, 0},

	{CPU_FTR_REAL_LE, 0, PPC_FEATURE_TRUE_LE, 0, 5, 0, 0},

	{ .pabyte = 0,  .pabit = 0, .cpu_user_ftrs = PPC_FEATURE_HAS_MMU },

	{ .pabyte = 0,  .pabit = 1, .cpu_user_ftrs = PPC_FEATURE_HAS_FPU },

	{ .pabyte = 0,  .pabit = 3, .cpu_features  = CPU_FTR_CTRL },

	{ .pabyte = 0,  .pabit = 6, .cpu_features  = CPU_FTR_NOEXECUTE },

	{ .pabyte = 1,  .pabit = 2, .mmu_features  = MMU_FTR_CI_LARGE_PAGE },

	{ .pabyte = 40, .pabit = 0, .mmu_features  = MMU_FTR_TYPE_RADIX },

	{ .pabyte = 1,  .pabit = 1, .invert = 1, .cpu_features = CPU_FTR_NODSISRALIGN },

	{ .pabyte = 5,  .pabit = 0, .cpu_features  = CPU_FTR_REAL_LE,

				    .cpu_user_ftrs = PPC_FEATURE_TRUE_LE },

	/*

	 * If the kernel doesn't support TM (ie CONFIG_PPC_TRANSACTIONAL_MEM=n),

	 * we don't want to turn on TM here, so we use the *_COMP versions

	 * which are 0 if the kernel doesn't support TM.

	 */

	{CPU_FTR_TM_COMP, 0, 0,

	 PPC_FEATURE2_HTM_COMP|PPC_FEATURE2_HTM_NOSC_COMP, 22, 0, 0},

	{0, MMU_FTR_TYPE_RADIX, 0, 0,		40, 0, 0},

	{ .pabyte = 22, .pabit = 0, .cpu_features = CPU_FTR_TM_COMP,

	  .cpu_user_ftrs2 = PPC_FEATURE2_HTM_COMP | PPC_FEATURE2_HTM_NOSC_COMP },

};



static void __init scan_features(unsigned long node, const unsigned char *ftrs,

CRA Git | Maintained and supported by SUSTech CRA and CCSE