Unverified Commit 73448ae6 authored by Palmer Dabbelt's avatar Palmer Dabbelt
Browse files

RISC-V: Some Svpbmt fixes and cleanups 

Some additionals comments and notes from autobuilders received after the
series got applied, warranted some changes.

* 'riscv-svpbmt' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/palmer/linux:
  riscv: remove usage of function-pointers from cpufeatures and t-head errata
  riscv: make patch-function pointer more generic in cpu_manufacturer_info struct
  riscv: Improve description for RISCV_ISA_SVPBMT Kconfig symbol
  riscv: drop cpufeature_apply_feature tracking variable
  riscv: fix dependency for t-head errata
parents 89793a61 1771c8c9

arch/riscv/Kconfig

+7 −2
Original line number Diff line number Diff line
@@ -364,8 +364,13 @@ config RISCV_ISA_SVPBMT 
	select RISCV_ALTERNATIVE

	default y

	help

	   Adds support to dynamically detect the presence of the SVPBMT extension

	   (Supervisor-mode: page-based memory types) and enable its usage.

	   Adds support to dynamically detect the presence of the SVPBMT

	   ISA-extension (Supervisor-mode: page-based memory types) and

	   enable its usage.



	   The memory type for a page contains a combination of attributes

	   that indicate the cacheability, idempotency, and ordering

	   properties for access to that page.



	   The SVPBMT extension is only available on 64Bit cpus.

arch/riscv/Kconfig.erratas

+1 −0
Original line number Diff line number Diff line
@@ -35,6 +35,7 @@ config ERRATA_SIFIVE_CIP_1200 


config ERRATA_THEAD

	bool "T-HEAD errata"

	depends on !XIP_KERNEL

	select RISCV_ALTERNATIVE

	help

	  All T-HEAD errata Kconfig depend on this Kconfig. Disabling

arch/riscv/errata/thead/errata.c

+12 −26
Original line number Diff line number Diff line
@@ -14,40 +14,26 @@ 
#include <asm/patch.h>

#include <asm/vendorid_list.h>



struct errata_info {

	char name[ERRATA_STRING_LENGTH_MAX];

	bool (*check_func)(unsigned long arch_id, unsigned long impid);

	unsigned int stage;

};



static bool errata_mt_check_func(unsigned long  arch_id, unsigned long impid)

static bool errata_probe_pbmt(unsigned int stage,

			      unsigned long arch_id, unsigned long impid)

{

	if (arch_id != 0 || impid != 0)

		return false;



	if (stage == RISCV_ALTERNATIVES_EARLY_BOOT ||

	    stage == RISCV_ALTERNATIVES_MODULE)

		return true;

}



static const struct errata_info errata_list[ERRATA_THEAD_NUMBER] = {

	{

		.name = "memory-types",

		.stage = RISCV_ALTERNATIVES_EARLY_BOOT,

		.check_func = errata_mt_check_func

	},

};

	return false;

}



static u32 thead_errata_probe(unsigned int stage, unsigned long archid, unsigned long impid)

static u32 thead_errata_probe(unsigned int stage,

			      unsigned long archid, unsigned long impid)

{

	const struct errata_info *info;

	u32 cpu_req_errata = 0;

	int idx;



	for (idx = 0; idx < ERRATA_THEAD_NUMBER; idx++) {

		info = &errata_list[idx];



		if ((stage == RISCV_ALTERNATIVES_MODULE ||

		     info->stage == stage) && info->check_func(archid, impid))

			cpu_req_errata |= (1U << idx);

	}

	if (errata_probe_pbmt(stage, archid, impid))

		cpu_req_errata |= (1U << ERRATA_THEAD_PBMT);



	return cpu_req_errata;

}

arch/riscv/kernel/alternative.c

+9 −9
Original line number Diff line number Diff line
@@ -20,7 +20,7 @@ struct cpu_manufacturer_info_t { 
	unsigned long vendor_id;

	unsigned long arch_id;

	unsigned long imp_id;

	void (*vendor_patch_func)(struct alt_entry *begin, struct alt_entry *end,

	void (*patch_func)(struct alt_entry *begin, struct alt_entry *end,

				  unsigned long archid, unsigned long impid,

				  unsigned int stage);

};
@@ -40,16 +40,16 @@ static void __init_or_module riscv_fill_cpu_mfr_info(struct cpu_manufacturer_inf 
	switch (cpu_mfr_info->vendor_id) {

#ifdef CONFIG_ERRATA_SIFIVE

	case SIFIVE_VENDOR_ID:

		cpu_mfr_info->vendor_patch_func = sifive_errata_patch_func;

		cpu_mfr_info->patch_func = sifive_errata_patch_func;

		break;

#endif

#ifdef CONFIG_ERRATA_THEAD

	case THEAD_VENDOR_ID:

		cpu_mfr_info->vendor_patch_func = thead_errata_patch_func;

		cpu_mfr_info->patch_func = thead_errata_patch_func;

		break;

#endif

	default:

		cpu_mfr_info->vendor_patch_func = NULL;

		cpu_mfr_info->patch_func = NULL;

	}

}
@@ -68,10 +68,10 @@ static void __init_or_module _apply_alternatives(struct alt_entry *begin, 


	riscv_cpufeature_patch_func(begin, end, stage);



	if (!cpu_mfr_info.vendor_patch_func)

	if (!cpu_mfr_info.patch_func)

		return;



	cpu_mfr_info.vendor_patch_func(begin, end,

	cpu_mfr_info.patch_func(begin, end,

				cpu_mfr_info.arch_id,

				cpu_mfr_info.imp_id,

				stage);

arch/riscv/kernel/cpufeature.c

+11 −26
Original line number Diff line number Diff line
@@ -245,12 +245,7 @@ void __init riscv_fill_hwcap(void) 
}



#ifdef CONFIG_RISCV_ALTERNATIVE

struct cpufeature_info {

	char name[ERRATA_STRING_LENGTH_MAX];

	bool (*check_func)(unsigned int stage);

};



static bool __init_or_module cpufeature_svpbmt_check_func(unsigned int stage)

static bool __init_or_module cpufeature_probe_svpbmt(unsigned int stage)

{

#ifdef CONFIG_RISCV_ISA_SVPBMT

	switch (stage) {
@@ -264,26 +259,19 @@ static bool __init_or_module cpufeature_svpbmt_check_func(unsigned int stage) 
	return false;

}



static const struct cpufeature_info __initdata_or_module

cpufeature_list[CPUFEATURE_NUMBER] = {

	{

		.name = "svpbmt",

		.check_func = cpufeature_svpbmt_check_func

	},

};



/*

 * Probe presence of individual extensions.

 *

 * This code may also be executed before kernel relocation, so we cannot use

 * addresses generated by the address-of operator as they won't be valid in

 * this context.

 */

static u32 __init_or_module cpufeature_probe(unsigned int stage)

{

	const struct cpufeature_info *info;

	u32 cpu_req_feature = 0;

	int idx;



	for (idx = 0; idx < CPUFEATURE_NUMBER; idx++) {

		info = &cpufeature_list[idx];



		if (info->check_func(stage))

			cpu_req_feature |= (1U << idx);

	}

	if (cpufeature_probe_svpbmt(stage))

		cpu_req_feature |= (1U << CPUFEATURE_SVPBMT);



	return cpu_req_feature;

}
@@ -293,7 +281,6 @@ void __init_or_module riscv_cpufeature_patch_func(struct alt_entry *begin, 
						  unsigned int stage)

{

	u32 cpu_req_feature = cpufeature_probe(stage);

	u32 cpu_apply_feature = 0;

	struct alt_entry *alt;

	u32 tmp;
@@ -307,10 +294,8 @@ void __init_or_module riscv_cpufeature_patch_func(struct alt_entry *begin, 
		}



		tmp = (1U << alt->errata_id);

		if (cpu_req_feature & tmp) {

		if (cpu_req_feature & tmp)

			patch_text_nosync(alt->old_ptr, alt->alt_ptr, alt->alt_len);

			cpu_apply_feature |= tmp;

		}

	}

}

#endif