From patchwork Tue Sep 26 09:46:54 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Wang, Xiao W" X-Patchwork-Id: 726769 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 90551E7D275 for ; Tue, 26 Sep 2023 09:38:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234233AbjIZJit (ORCPT ); Tue, 26 Sep 2023 05:38:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49240 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234256AbjIZJir (ORCPT ); Tue, 26 Sep 2023 05:38:47 -0400 Received: from mgamail.intel.com (mgamail.intel.com [192.55.52.151]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EEC10124; Tue, 26 Sep 2023 02:38:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1695721119; x=1727257119; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=D2zk7hqw/NUeE67saE05yFlsZp65mZyDIWiC5Q8WdOE=; b=CnSq0mgmmgUjeGs9GVAOBj2SytzqFd1mtMPNU3NHfctPFdeGzqnML2gl urT/Mz2YZu68DSQmONWJW/qisXdNg92lzVqzUSl3/53Dwiti/989xR8gN 82QeX60tlkipaybMiXFBGUclcCxiEX0en60A29K7jKsA6LsUCtPWy+ioZ sbN20Nh98zEu28phhQhCGYeYcnXJzbiZjT42b/NC+EEWGuGv3lRkmVhP5 Ks79z7xBCF8JYnVMuBF1CcKWBkizfKCbR54w96zaDnR1+s30lGfUXY7UW 7Q0UqOdmF1U8TXfoVgOCRgHdCt/qefm81o93nkrdVxAh+8tTfSjPEXa6q Q==; X-IronPort-AV: E=McAfee;i="6600,9927,10843"; a="361773035" X-IronPort-AV: E=Sophos;i="6.03,177,1694761200"; d="scan'208";a="361773035" Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 Sep 2023 02:38:39 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10843"; a="995767918" X-IronPort-AV: E=Sophos;i="6.03,177,1694761200"; d="scan'208";a="995767918" Received: from xiao-desktop.sh.intel.com ([10.239.46.158]) by fmsmga006.fm.intel.com with ESMTP; 26 Sep 2023 02:38:36 -0700 From: Xiao Wang To: paul.walmsley@sifive.com, palmer@dabbelt.com, aou@eecs.berkeley.edu, ardb@kernel.org Cc: anup@brainfault.org, haicheng.li@intel.com, ajones@ventanamicro.com, yujie.liu@intel.com, linux-riscv@lists.infradead.org, linux-efi@vger.kernel.org, linux-kernel@vger.kernel.org, Xiao Wang Subject: [PATCH v3 1/2] riscv: Rearrange hwcap.h and cpufeature.h Date: Tue, 26 Sep 2023 17:46:54 +0800 Message-Id: <20230926094655.3102758-2-xiao.w.wang@intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20230926094655.3102758-1-xiao.w.wang@intel.com> References: <20230926094655.3102758-1-xiao.w.wang@intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-efi@vger.kernel.org Now hwcap.h and cpufeature.h are mutually including each other, and most of the variable/API declarations in hwcap.h are implemented in cpufeature.c, so, it's better to move them into cpufeature.h and leave only macros for ISA extension logical IDs in hwcap.h. BTW, the riscv_isa_extension_mask macro is not used now, so this patch removes it. Suggested-by: Andrew Jones Signed-off-by: Xiao Wang Reviewed-by: Andrew Jones --- arch/riscv/include/asm/cpufeature.h | 83 ++++++++++++++++++++++++++ arch/riscv/include/asm/elf.h | 2 +- arch/riscv/include/asm/hwcap.h | 91 ----------------------------- arch/riscv/include/asm/pgtable.h | 1 + arch/riscv/include/asm/switch_to.h | 2 +- arch/riscv/include/asm/vector.h | 2 +- arch/riscv/kvm/aia.c | 2 +- arch/riscv/kvm/main.c | 2 +- arch/riscv/kvm/tlb.c | 2 +- arch/riscv/kvm/vcpu_fp.c | 2 +- arch/riscv/kvm/vcpu_onereg.c | 2 +- arch/riscv/kvm/vcpu_vector.c | 2 +- drivers/clocksource/timer-riscv.c | 2 +- drivers/perf/riscv_pmu_sbi.c | 2 +- 14 files changed, 95 insertions(+), 102 deletions(-) diff --git a/arch/riscv/include/asm/cpufeature.h b/arch/riscv/include/asm/cpufeature.h index 13b7d35648a9..3061d33abc2f 100644 --- a/arch/riscv/include/asm/cpufeature.h +++ b/arch/riscv/include/asm/cpufeature.h @@ -7,7 +7,10 @@ #define _ASM_CPUFEATURE_H #include +#include #include +#include +#include /* * These are probed via a device_initcall(), via either the SBI or directly @@ -33,4 +36,84 @@ extern struct riscv_isainfo hart_isa[NR_CPUS]; void check_unaligned_access(int cpu); void riscv_user_isa_enable(void); +unsigned long riscv_get_elf_hwcap(void); + +struct riscv_isa_ext_data { + const unsigned int id; + const char *name; + const char *property; +}; + +extern const struct riscv_isa_ext_data riscv_isa_ext[]; +extern const size_t riscv_isa_ext_count; +extern bool riscv_isa_fallback; + +unsigned long riscv_isa_extension_base(const unsigned long *isa_bitmap); + +bool __riscv_isa_extension_available(const unsigned long *isa_bitmap, int bit); +#define riscv_isa_extension_available(isa_bitmap, ext) \ + __riscv_isa_extension_available(isa_bitmap, RISCV_ISA_EXT_##ext) + +static __always_inline bool +riscv_has_extension_likely(const unsigned long ext) +{ + compiletime_assert(ext < RISCV_ISA_EXT_MAX, + "ext must be < RISCV_ISA_EXT_MAX"); + + if (IS_ENABLED(CONFIG_RISCV_ALTERNATIVE)) { + asm_volatile_goto( + ALTERNATIVE("j %l[l_no]", "nop", 0, %[ext], 1) + : + : [ext] "i" (ext) + : + : l_no); + } else { + if (!__riscv_isa_extension_available(NULL, ext)) + goto l_no; + } + + return true; +l_no: + return false; +} + +static __always_inline bool +riscv_has_extension_unlikely(const unsigned long ext) +{ + compiletime_assert(ext < RISCV_ISA_EXT_MAX, + "ext must be < RISCV_ISA_EXT_MAX"); + + if (IS_ENABLED(CONFIG_RISCV_ALTERNATIVE)) { + asm_volatile_goto( + ALTERNATIVE("nop", "j %l[l_yes]", 0, %[ext], 1) + : + : [ext] "i" (ext) + : + : l_yes); + } else { + if (__riscv_isa_extension_available(NULL, ext)) + goto l_yes; + } + + return false; +l_yes: + return true; +} + +static __always_inline bool riscv_cpu_has_extension_likely(int cpu, const unsigned long ext) +{ + if (IS_ENABLED(CONFIG_RISCV_ALTERNATIVE) && riscv_has_extension_likely(ext)) + return true; + + return __riscv_isa_extension_available(hart_isa[cpu].isa, ext); +} + +static __always_inline bool riscv_cpu_has_extension_unlikely(int cpu, const unsigned long ext) +{ + if (IS_ENABLED(CONFIG_RISCV_ALTERNATIVE) && riscv_has_extension_unlikely(ext)) + return true; + + return __riscv_isa_extension_available(hart_isa[cpu].isa, ext); +} + #endif diff --git a/arch/riscv/include/asm/elf.h b/arch/riscv/include/asm/elf.h index b3b2dfbdf945..06c236bfab53 100644 --- a/arch/riscv/include/asm/elf.h +++ b/arch/riscv/include/asm/elf.h @@ -14,7 +14,7 @@ #include #include #include -#include +#include /* * These are used to set parameters in the core dumps. diff --git a/arch/riscv/include/asm/hwcap.h b/arch/riscv/include/asm/hwcap.h index 31774bcdf1c6..141b7109c25c 100644 --- a/arch/riscv/include/asm/hwcap.h +++ b/arch/riscv/include/asm/hwcap.h @@ -8,9 +8,6 @@ #ifndef _ASM_RISCV_HWCAP_H #define _ASM_RISCV_HWCAP_H -#include -#include -#include #include #define RISCV_ISA_EXT_a ('a' - 'a') @@ -67,92 +64,4 @@ #define RISCV_ISA_EXT_SxAIA RISCV_ISA_EXT_SSAIA #endif -#ifndef __ASSEMBLY__ - -#include -#include - -unsigned long riscv_get_elf_hwcap(void); - -struct riscv_isa_ext_data { - const unsigned int id; - const char *name; - const char *property; -}; - -extern const struct riscv_isa_ext_data riscv_isa_ext[]; -extern const size_t riscv_isa_ext_count; -extern bool riscv_isa_fallback; - -unsigned long riscv_isa_extension_base(const unsigned long *isa_bitmap); - -#define riscv_isa_extension_mask(ext) BIT_MASK(RISCV_ISA_EXT_##ext) - -bool __riscv_isa_extension_available(const unsigned long *isa_bitmap, int bit); -#define riscv_isa_extension_available(isa_bitmap, ext) \ - __riscv_isa_extension_available(isa_bitmap, RISCV_ISA_EXT_##ext) - -static __always_inline bool -riscv_has_extension_likely(const unsigned long ext) -{ - compiletime_assert(ext < RISCV_ISA_EXT_MAX, - "ext must be < RISCV_ISA_EXT_MAX"); - - if (IS_ENABLED(CONFIG_RISCV_ALTERNATIVE)) { - asm_volatile_goto( - ALTERNATIVE("j %l[l_no]", "nop", 0, %[ext], 1) - : - : [ext] "i" (ext) - : - : l_no); - } else { - if (!__riscv_isa_extension_available(NULL, ext)) - goto l_no; - } - - return true; -l_no: - return false; -} - -static __always_inline bool -riscv_has_extension_unlikely(const unsigned long ext) -{ - compiletime_assert(ext < RISCV_ISA_EXT_MAX, - "ext must be < RISCV_ISA_EXT_MAX"); - - if (IS_ENABLED(CONFIG_RISCV_ALTERNATIVE)) { - asm_volatile_goto( - ALTERNATIVE("nop", "j %l[l_yes]", 0, %[ext], 1) - : - : [ext] "i" (ext) - : - : l_yes); - } else { - if (__riscv_isa_extension_available(NULL, ext)) - goto l_yes; - } - - return false; -l_yes: - return true; -} - -static __always_inline bool riscv_cpu_has_extension_likely(int cpu, const unsigned long ext) -{ - if (IS_ENABLED(CONFIG_RISCV_ALTERNATIVE) && riscv_has_extension_likely(ext)) - return true; - - return __riscv_isa_extension_available(hart_isa[cpu].isa, ext); -} - -static __always_inline bool riscv_cpu_has_extension_unlikely(int cpu, const unsigned long ext) -{ - if (IS_ENABLED(CONFIG_RISCV_ALTERNATIVE) && riscv_has_extension_unlikely(ext)) - return true; - - return __riscv_isa_extension_available(hart_isa[cpu].isa, ext); -} -#endif - #endif /* _ASM_RISCV_HWCAP_H */ diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h index b2ba3f79cfe9..e05b5dc1f0cb 100644 --- a/arch/riscv/include/asm/pgtable.h +++ b/arch/riscv/include/asm/pgtable.h @@ -291,6 +291,7 @@ static inline pte_t pud_pte(pud_t pud) } #ifdef CONFIG_RISCV_ISA_SVNAPOT +#include static __always_inline bool has_svnapot(void) { diff --git a/arch/riscv/include/asm/switch_to.h b/arch/riscv/include/asm/switch_to.h index a727be723c56..f90d8e42f3c7 100644 --- a/arch/riscv/include/asm/switch_to.h +++ b/arch/riscv/include/asm/switch_to.h @@ -9,7 +9,7 @@ #include #include #include -#include +#include #include #include #include diff --git a/arch/riscv/include/asm/vector.h b/arch/riscv/include/asm/vector.h index c5ee07b3df07..87aaef656257 100644 --- a/arch/riscv/include/asm/vector.h +++ b/arch/riscv/include/asm/vector.h @@ -15,7 +15,7 @@ #include #include #include -#include +#include #include #include diff --git a/arch/riscv/kvm/aia.c b/arch/riscv/kvm/aia.c index 74bb27440527..a944294f6f23 100644 --- a/arch/riscv/kvm/aia.c +++ b/arch/riscv/kvm/aia.c @@ -14,7 +14,7 @@ #include #include #include -#include +#include #include struct aia_hgei_control { diff --git a/arch/riscv/kvm/main.c b/arch/riscv/kvm/main.c index 48ae0d4b3932..225a435d9c9a 100644 --- a/arch/riscv/kvm/main.c +++ b/arch/riscv/kvm/main.c @@ -11,7 +11,7 @@ #include #include #include -#include +#include #include long kvm_arch_dev_ioctl(struct file *filp, diff --git a/arch/riscv/kvm/tlb.c b/arch/riscv/kvm/tlb.c index 44bc324aeeb0..23c0e82b5103 100644 --- a/arch/riscv/kvm/tlb.c +++ b/arch/riscv/kvm/tlb.c @@ -12,7 +12,7 @@ #include #include #include -#include +#include #include #define has_svinval() riscv_has_extension_unlikely(RISCV_ISA_EXT_SVINVAL) diff --git a/arch/riscv/kvm/vcpu_fp.c b/arch/riscv/kvm/vcpu_fp.c index 08ba48a395aa..030904d82b58 100644 --- a/arch/riscv/kvm/vcpu_fp.c +++ b/arch/riscv/kvm/vcpu_fp.c @@ -11,7 +11,7 @@ #include #include #include -#include +#include #ifdef CONFIG_FPU void kvm_riscv_vcpu_fp_reset(struct kvm_vcpu *vcpu) diff --git a/arch/riscv/kvm/vcpu_onereg.c b/arch/riscv/kvm/vcpu_onereg.c index 1b7e9fa265cb..b03e0c879dab 100644 --- a/arch/riscv/kvm/vcpu_onereg.c +++ b/arch/riscv/kvm/vcpu_onereg.c @@ -13,7 +13,7 @@ #include #include #include -#include +#include #include #include diff --git a/arch/riscv/kvm/vcpu_vector.c b/arch/riscv/kvm/vcpu_vector.c index b430cbb69521..b339a2682f25 100644 --- a/arch/riscv/kvm/vcpu_vector.c +++ b/arch/riscv/kvm/vcpu_vector.c @@ -11,7 +11,7 @@ #include #include #include -#include +#include #include #include diff --git a/drivers/clocksource/timer-riscv.c b/drivers/clocksource/timer-riscv.c index da3071b387eb..6d9e344e98f8 100644 --- a/drivers/clocksource/timer-riscv.c +++ b/drivers/clocksource/timer-riscv.c @@ -24,7 +24,7 @@ #include #include #include -#include +#include #include #include diff --git a/drivers/perf/riscv_pmu_sbi.c b/drivers/perf/riscv_pmu_sbi.c index 9a51053b1f99..b97d3f1abcb1 100644 --- a/drivers/perf/riscv_pmu_sbi.c +++ b/drivers/perf/riscv_pmu_sbi.c @@ -22,7 +22,7 @@ #include #include -#include +#include #define SYSCTL_NO_USER_ACCESS 0 #define SYSCTL_USER_ACCESS 1 From patchwork Tue Sep 26 09:46:55 2023 Content-Type: text/plain; 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26 Sep 2023 02:38:40 -0700 From: Xiao Wang To: paul.walmsley@sifive.com, palmer@dabbelt.com, aou@eecs.berkeley.edu, ardb@kernel.org Cc: anup@brainfault.org, haicheng.li@intel.com, ajones@ventanamicro.com, yujie.liu@intel.com, linux-riscv@lists.infradead.org, linux-efi@vger.kernel.org, linux-kernel@vger.kernel.org, Xiao Wang Subject: [PATCH v3 2/2] riscv: Optimize bitops with Zbb extension Date: Tue, 26 Sep 2023 17:46:55 +0800 Message-Id: <20230926094655.3102758-3-xiao.w.wang@intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20230926094655.3102758-1-xiao.w.wang@intel.com> References: <20230926094655.3102758-1-xiao.w.wang@intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-efi@vger.kernel.org This patch leverages the alternative mechanism to dynamically optimize bitops (including __ffs, __fls, ffs, fls) with Zbb instructions. When Zbb ext is not supported by the runtime CPU, legacy implementation is used. If Zbb is supported, then the optimized variants will be selected via alternative patching. The legacy bitops support is taken from the generic C implementation as fallback. If the parameter is a build-time constant, we leverage compiler builtin to calculate the result directly, this approach is inspired by x86 bitops implementation. EFI stub runs before the kernel, so alternative mechanism should not be used there, this patch introduces a macro NO_ALTERNATIVE for this purpose. Signed-off-by: Xiao Wang --- arch/riscv/include/asm/bitops.h | 266 +++++++++++++++++++++++++- drivers/firmware/efi/libstub/Makefile | 2 +- 2 files changed, 264 insertions(+), 4 deletions(-) diff --git a/arch/riscv/include/asm/bitops.h b/arch/riscv/include/asm/bitops.h index 3540b690944b..c97e774cb647 100644 --- a/arch/riscv/include/asm/bitops.h +++ b/arch/riscv/include/asm/bitops.h @@ -15,13 +15,273 @@ #include #include +#if !defined(CONFIG_RISCV_ISA_ZBB) || defined(NO_ALTERNATIVE) #include -#include -#include #include +#include +#include + +#else +#include +#include + +#if (BITS_PER_LONG == 64) +#define CTZW "ctzw " +#define CLZW "clzw " +#elif (BITS_PER_LONG == 32) +#define CTZW "ctz " +#define CLZW "clz " +#else +#error "Unexpected BITS_PER_LONG" +#endif + +static __always_inline unsigned long variable__ffs(unsigned long word) +{ + int num; + + asm_volatile_goto( + ALTERNATIVE("j %l[legacy]", "nop", 0, RISCV_ISA_EXT_ZBB, 1) + : : : : legacy); + + asm volatile ( + ".option push\n" + ".option arch,+zbb\n" + "ctz %0, %1\n" + ".option pop\n" + : "=r" (word) : "r" (word) :); + + return word; + +legacy: + num = 0; +#if BITS_PER_LONG == 64 + if ((word & 0xffffffff) == 0) { + num += 32; + word >>= 32; + } +#endif + if ((word & 0xffff) == 0) { + num += 16; + word >>= 16; + } + if ((word & 0xff) == 0) { + num += 8; + word >>= 8; + } + if ((word & 0xf) == 0) { + num += 4; + word >>= 4; + } + if ((word & 0x3) == 0) { + num += 2; + word >>= 2; + } + if ((word & 0x1) == 0) + num += 1; + return num; +} + +/** + * __ffs - find first set bit in a long word + * @word: The word to search + * + * Undefined if no set bit exists, so code should check against 0 first. + */ +#define __ffs(word) \ + (__builtin_constant_p(word) ? \ + (unsigned long)__builtin_ctzl(word) : \ + variable__ffs(word)) + +static __always_inline unsigned long variable__fls(unsigned long word) +{ + int num; + + asm_volatile_goto( + ALTERNATIVE("j %l[legacy]", "nop", 0, RISCV_ISA_EXT_ZBB, 1) + : : : : legacy); + + asm volatile ( + ".option push\n" + ".option arch,+zbb\n" + "clz %0, %1\n" + ".option pop\n" + : "=r" (word) : "r" (word) :); + + return BITS_PER_LONG - 1 - word; + +legacy: + num = BITS_PER_LONG - 1; +#if BITS_PER_LONG == 64 + if (!(word & (~0ul << 32))) { + num -= 32; + word <<= 32; + } +#endif + if (!(word & (~0ul << (BITS_PER_LONG-16)))) { + num -= 16; + word <<= 16; + } + if (!(word & (~0ul << (BITS_PER_LONG-8)))) { + num -= 8; + word <<= 8; + } + if (!(word & (~0ul << (BITS_PER_LONG-4)))) { + num -= 4; + word <<= 4; + } + if (!(word & (~0ul << (BITS_PER_LONG-2)))) { + num -= 2; + word <<= 2; + } + if (!(word & (~0ul << (BITS_PER_LONG-1)))) + num -= 1; + return num; +} + +/** + * __fls - find last set bit in a long word + * @word: the word to search + * + * Undefined if no set bit exists, so code should check against 0 first. + */ +#define __fls(word) \ + (__builtin_constant_p(word) ? \ + (unsigned long)(BITS_PER_LONG - 1 - __builtin_clzl(word)) : \ + variable__fls(word)) + +static __always_inline int variable_ffs(int x) +{ + int r; + + asm_volatile_goto( + ALTERNATIVE("j %l[legacy]", "nop", 0, RISCV_ISA_EXT_ZBB, 1) + : : : : legacy); + + asm volatile ( + ".option push\n" + ".option arch,+zbb\n" + "bnez %1, 1f\n" + "li %0, 0\n" + "j 2f\n" + "1:\n" + CTZW "%0, %1\n" + "addi %0, %0, 1\n" + "2:\n" + ".option pop\n" + : "=r" (r) : "r" (x) :); + + return r; + +legacy: + r = 1; + if (!x) + return 0; + if (!(x & 0xffff)) { + x >>= 16; + r += 16; + } + if (!(x & 0xff)) { + x >>= 8; + r += 8; + } + if (!(x & 0xf)) { + x >>= 4; + r += 4; + } + if (!(x & 3)) { + x >>= 2; + r += 2; + } + if (!(x & 1)) { + x >>= 1; + r += 1; + } + return r; +} + +/** + * ffs - find first set bit in a word + * @x: the word to search + * + * This is defined the same way as the libc and compiler builtin ffs routines. + * + * ffs(value) returns 0 if value is 0 or the position of the first set bit if + * value is nonzero. The first (least significant) bit is at position 1. + */ +#define ffs(x) (__builtin_constant_p(x) ? __builtin_ffs(x) : variable_ffs(x)) + +static __always_inline int variable_fls(unsigned int x) +{ + int r; + + asm_volatile_goto( + ALTERNATIVE("j %l[legacy]", "nop", 0, RISCV_ISA_EXT_ZBB, 1) + : : : : legacy); + + asm volatile ( + ".option push\n" + ".option arch,+zbb\n" + "bnez %1, 1f\n" + "li %0, 0\n" + "j 2f\n" + "1:\n" + CLZW "%0, %1\n" + "neg %0, %0\n" + "addi %0, %0, 32\n" + "2:\n" + ".option pop\n" + : "=r" (r) : "r" (x) :); + + return r; + +legacy: + r = 32; + if (!x) + return 0; + if (!(x & 0xffff0000u)) { + x <<= 16; + r -= 16; + } + if (!(x & 0xff000000u)) { + x <<= 8; + r -= 8; + } + if (!(x & 0xf0000000u)) { + x <<= 4; + r -= 4; + } + if (!(x & 0xc0000000u)) { + x <<= 2; + r -= 2; + } + if (!(x & 0x80000000u)) { + x <<= 1; + r -= 1; + } + return r; +} + +/** + * fls - find last set bit in a word + * @x: the word to search + * + * This is defined in a similar way as ffs, but returns the position of the most + * significant set bit. + * + * fls(value) returns 0 if value is 0 or the position of the last set bit if + * value is nonzero. The last (most significant) bit is at position 32. + */ +#define fls(x) \ + (__builtin_constant_p(x) ? \ + (int)(((x) != 0) ? \ + (sizeof(unsigned int) * 8 - __builtin_clz(x)) : 0) : \ + variable_fls(x)) + +#endif + +#include #include #include -#include #include diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile index a1157c2a7170..d68cacd4e3af 100644 --- a/drivers/firmware/efi/libstub/Makefile +++ b/drivers/firmware/efi/libstub/Makefile @@ -28,7 +28,7 @@ cflags-$(CONFIG_ARM) += -DEFI_HAVE_STRLEN -DEFI_HAVE_STRNLEN \ -DEFI_HAVE_MEMCHR -DEFI_HAVE_STRRCHR \ -DEFI_HAVE_STRCMP -fno-builtin -fpic \ $(call cc-option,-mno-single-pic-base) -cflags-$(CONFIG_RISCV) += -fpic +cflags-$(CONFIG_RISCV) += -fpic -DNO_ALTERNATIVE cflags-$(CONFIG_LOONGARCH) += -fpie cflags-$(CONFIG_EFI_PARAMS_FROM_FDT) += -I$(srctree)/scripts/dtc/libfdt