linux/arch/arm/include/asm/assembler.h

795 lines
17 KiB

ARM: 9358/2: Implement PAN for LPAE by TTBR0 page table walks disablement With LPAE enabled, privileged no-access cannot be enforced using CPU domains as such feature is not available. This patch implements PAN by disabling TTBR0 page table walks while in kernel mode. The ARM architecture allows page table walks to be split between TTBR0 and TTBR1. With LPAE enabled, the split is defined by a combination of TTBCR T0SZ and T1SZ bits. Currently, an LPAE-enabled kernel uses TTBR0 for user addresses and TTBR1 for kernel addresses with the VMSPLIT_2G and VMSPLIT_3G configurations. The main advantage for the 3:1 split is that TTBR1 is reduced to 2 levels, so potentially faster TLB refill (though usually the first level entries are already cached in the TLB). The PAN support on LPAE-enabled kernels uses TTBR0 when running in user space or in kernel space during user access routines (TTBCR T0SZ and T1SZ are both 0). When running user accesses are disabled in kernel mode, TTBR0 page table walks are disabled by setting TTBCR.EPD0. TTBR1 is used for kernel accesses (including loadable modules; anything covered by swapper_pg_dir) by reducing the TTBCR.T0SZ to the minimum (2^(32-7) = 32MB). To avoid user accesses potentially hitting stale TLB entries, the ASID is switched to 0 (reserved) by setting TTBCR.A1 and using the ASID value in TTBR1. The difference from a non-PAN kernel is that with the 3:1 memory split, TTBR1 always uses 3 levels of page tables. As part of the change we are using preprocessor elif definied() clauses so balance these clauses by converting relevant precedingt ifdef clauses to if defined() clauses. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Kees Cook <keescook@chromium.org> Tested-by: Florian Fainelli <florian.fainelli@broadcom.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
2024-03-25 08:31:13 +01:00
ARM: 8812/1: Optimise copy_{from/to}_user for !CPU_USE_DOMAINS ARMv6+ processors do not use CONFIG_CPU_USE_DOMAINS and use privileged ldr/str instructions in copy_{from/to}_user. They are currently unnecessarily using single ldr/str instructions and can use ldm/stm instructions instead like memcpy does (but with appropriate fixup tables). This speeds up a "dd if=foo of=bar bs=32k" on a tmpfs filesystem by about 4% on my Cortex-A9. before:134217728 bytes (128.0MB) copied, 0.543848 seconds, 235.4MB/s before:134217728 bytes (128.0MB) copied, 0.538610 seconds, 237.6MB/s before:134217728 bytes (128.0MB) copied, 0.544356 seconds, 235.1MB/s before:134217728 bytes (128.0MB) copied, 0.544364 seconds, 235.1MB/s before:134217728 bytes (128.0MB) copied, 0.537130 seconds, 238.3MB/s before:134217728 bytes (128.0MB) copied, 0.533443 seconds, 240.0MB/s before:134217728 bytes (128.0MB) copied, 0.545691 seconds, 234.6MB/s before:134217728 bytes (128.0MB) copied, 0.534695 seconds, 239.4MB/s before:134217728 bytes (128.0MB) copied, 0.540561 seconds, 236.8MB/s before:134217728 bytes (128.0MB) copied, 0.541025 seconds, 236.6MB/s after:134217728 bytes (128.0MB) copied, 0.520445 seconds, 245.9MB/s after:134217728 bytes (128.0MB) copied, 0.527846 seconds, 242.5MB/s after:134217728 bytes (128.0MB) copied, 0.519510 seconds, 246.4MB/s after:134217728 bytes (128.0MB) copied, 0.527231 seconds, 242.8MB/s after:134217728 bytes (128.0MB) copied, 0.525030 seconds, 243.8MB/s after:134217728 bytes (128.0MB) copied, 0.524236 seconds, 244.2MB/s after:134217728 bytes (128.0MB) copied, 0.523659 seconds, 244.4MB/s after:134217728 bytes (128.0MB) copied, 0.525018 seconds, 243.8MB/s after:134217728 bytes (128.0MB) copied, 0.519249 seconds, 246.5MB/s after:134217728 bytes (128.0MB) copied, 0.518527 seconds, 246.9MB/s Reviewed-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2018-11-09 10:09:48 +01:00
ARM: 8812/1: Optimise copy_{from/to}_user for !CPU_USE_DOMAINS ARMv6+ processors do not use CONFIG_CPU_USE_DOMAINS and use privileged ldr/str instructions in copy_{from/to}_user. They are currently unnecessarily using single ldr/str instructions and can use ldm/stm instructions instead like memcpy does (but with appropriate fixup tables). This speeds up a "dd if=foo of=bar bs=32k" on a tmpfs filesystem by about 4% on my Cortex-A9. before:134217728 bytes (128.0MB) copied, 0.543848 seconds, 235.4MB/s before:134217728 bytes (128.0MB) copied, 0.538610 seconds, 237.6MB/s before:134217728 bytes (128.0MB) copied, 0.544356 seconds, 235.1MB/s before:134217728 bytes (128.0MB) copied, 0.544364 seconds, 235.1MB/s before:134217728 bytes (128.0MB) copied, 0.537130 seconds, 238.3MB/s before:134217728 bytes (128.0MB) copied, 0.533443 seconds, 240.0MB/s before:134217728 bytes (128.0MB) copied, 0.545691 seconds, 234.6MB/s before:134217728 bytes (128.0MB) copied, 0.534695 seconds, 239.4MB/s before:134217728 bytes (128.0MB) copied, 0.540561 seconds, 236.8MB/s before:134217728 bytes (128.0MB) copied, 0.541025 seconds, 236.6MB/s after:134217728 bytes (128.0MB) copied, 0.520445 seconds, 245.9MB/s after:134217728 bytes (128.0MB) copied, 0.527846 seconds, 242.5MB/s after:134217728 bytes (128.0MB) copied, 0.519510 seconds, 246.4MB/s after:134217728 bytes (128.0MB) copied, 0.527231 seconds, 242.8MB/s after:134217728 bytes (128.0MB) copied, 0.525030 seconds, 243.8MB/s after:134217728 bytes (128.0MB) copied, 0.524236 seconds, 244.2MB/s after:134217728 bytes (128.0MB) copied, 0.523659 seconds, 244.4MB/s after:134217728 bytes (128.0MB) copied, 0.525018 seconds, 243.8MB/s after:134217728 bytes (128.0MB) copied, 0.519249 seconds, 246.5MB/s after:134217728 bytes (128.0MB) copied, 0.518527 seconds, 246.9MB/s Reviewed-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2018-11-09 10:09:48 +01:00
ARM: 8812/1: Optimise copy_{from/to}_user for !CPU_USE_DOMAINS ARMv6+ processors do not use CONFIG_CPU_USE_DOMAINS and use privileged ldr/str instructions in copy_{from/to}_user. They are currently unnecessarily using single ldr/str instructions and can use ldm/stm instructions instead like memcpy does (but with appropriate fixup tables). This speeds up a "dd if=foo of=bar bs=32k" on a tmpfs filesystem by about 4% on my Cortex-A9. before:134217728 bytes (128.0MB) copied, 0.543848 seconds, 235.4MB/s before:134217728 bytes (128.0MB) copied, 0.538610 seconds, 237.6MB/s before:134217728 bytes (128.0MB) copied, 0.544356 seconds, 235.1MB/s before:134217728 bytes (128.0MB) copied, 0.544364 seconds, 235.1MB/s before:134217728 bytes (128.0MB) copied, 0.537130 seconds, 238.3MB/s before:134217728 bytes (128.0MB) copied, 0.533443 seconds, 240.0MB/s before:134217728 bytes (128.0MB) copied, 0.545691 seconds, 234.6MB/s before:134217728 bytes (128.0MB) copied, 0.534695 seconds, 239.4MB/s before:134217728 bytes (128.0MB) copied, 0.540561 seconds, 236.8MB/s before:134217728 bytes (128.0MB) copied, 0.541025 seconds, 236.6MB/s after:134217728 bytes (128.0MB) copied, 0.520445 seconds, 245.9MB/s after:134217728 bytes (128.0MB) copied, 0.527846 seconds, 242.5MB/s after:134217728 bytes (128.0MB) copied, 0.519510 seconds, 246.4MB/s after:134217728 bytes (128.0MB) copied, 0.527231 seconds, 242.8MB/s after:134217728 bytes (128.0MB) copied, 0.525030 seconds, 243.8MB/s after:134217728 bytes (128.0MB) copied, 0.524236 seconds, 244.2MB/s after:134217728 bytes (128.0MB) copied, 0.523659 seconds, 244.4MB/s after:134217728 bytes (128.0MB) copied, 0.525018 seconds, 243.8MB/s after:134217728 bytes (128.0MB) copied, 0.519249 seconds, 246.5MB/s after:134217728 bytes (128.0MB) copied, 0.518527 seconds, 246.9MB/s Reviewed-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2018-11-09 10:09:48 +01:00
ARM: 6516/1: Allow SMP_ON_UP to work with Thumb-2 kernels. * __fixup_smp_on_up has been modified with support for the THUMB2_KERNEL case. For THUMB2_KERNEL only, fixups are split into halfwords in case of misalignment, since we can't rely on unaligned accesses working before turning the MMU on. No attempt is made to optimise the aligned case, since the number of fixups is typically small, and it seems best to keep the code as simple as possible. * Add a rotate in the fixup_smp code in order to support CPU_BIG_ENDIAN, as suggested by Nicolas Pitre. * Add an assembly-time sanity-check to ALT_UP() to ensure that the content really is the right size (4 bytes). (No check is done for ALT_SMP(). Possibly, this could be fixed by splitting the two uses ot ALT_SMP() (ALT_SMP...SMP_UP versus ALT_SMP...SMP_UP_B) into two macros. In the first case, ALT_SMP needs to expand to >= 4 bytes, not == 4.) * smp_mpidr.h (which implements ALT_SMP()/ALT_UP() manually due to macro limitations) has not been modified: the affected instruction (mov) has no 16-bit encoding, so the correct instruction size is satisfied in this case. * A "mode" parameter has been added to smp_dmb: smp_dmb arm @ assumes 4-byte instructions (for ARM code, e.g. kuser) smp_dmb @ uses W() to ensure 4-byte instructions for ALT_SMP() This avoids assembly failures due to use of W() inside smp_dmb, when assembling pure-ARM code in the vectors page. There might be a better way to achieve this. * Kconfig: make SMP_ON_UP depend on (!THUMB2_KERNEL || !BIG_ENDIAN) i.e., THUMB2_KERNEL is now supported, but only if !BIG_ENDIAN (The fixup code for Thumb-2 currently assumes little-endian order.) Tested using a single generic realview kernel on: ARM RealView PB-A8 (CONFIG_THUMB2_KERNEL={n,y}) ARM RealView PBX-A9 (SMP) Signed-off-by: Dave Martin <dave.martin@linaro.org> Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-12-01 15:39:23 +01:00
ARM: 6516/1: Allow SMP_ON_UP to work with Thumb-2 kernels. * __fixup_smp_on_up has been modified with support for the THUMB2_KERNEL case. For THUMB2_KERNEL only, fixups are split into halfwords in case of misalignment, since we can't rely on unaligned accesses working before turning the MMU on. No attempt is made to optimise the aligned case, since the number of fixups is typically small, and it seems best to keep the code as simple as possible. * Add a rotate in the fixup_smp code in order to support CPU_BIG_ENDIAN, as suggested by Nicolas Pitre. * Add an assembly-time sanity-check to ALT_UP() to ensure that the content really is the right size (4 bytes). (No check is done for ALT_SMP(). Possibly, this could be fixed by splitting the two uses ot ALT_SMP() (ALT_SMP...SMP_UP versus ALT_SMP...SMP_UP_B) into two macros. In the first case, ALT_SMP needs to expand to >= 4 bytes, not == 4.) * smp_mpidr.h (which implements ALT_SMP()/ALT_UP() manually due to macro limitations) has not been modified: the affected instruction (mov) has no 16-bit encoding, so the correct instruction size is satisfied in this case. * A "mode" parameter has been added to smp_dmb: smp_dmb arm @ assumes 4-byte instructions (for ARM code, e.g. kuser) smp_dmb @ uses W() to ensure 4-byte instructions for ALT_SMP() This avoids assembly failures due to use of W() inside smp_dmb, when assembling pure-ARM code in the vectors page. There might be a better way to achieve this. * Kconfig: make SMP_ON_UP depend on (!THUMB2_KERNEL || !BIG_ENDIAN) i.e., THUMB2_KERNEL is now supported, but only if !BIG_ENDIAN (The fixup code for Thumb-2 currently assumes little-endian order.) Tested using a single generic realview kernel on: ARM RealView PB-A8 (CONFIG_THUMB2_KERNEL={n,y}) ARM RealView PBX-A9 (SMP) Signed-off-by: Dave Martin <dave.martin@linaro.org> Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-12-01 15:39:23 +01:00
ARM: 6516/1: Allow SMP_ON_UP to work with Thumb-2 kernels. * __fixup_smp_on_up has been modified with support for the THUMB2_KERNEL case. For THUMB2_KERNEL only, fixups are split into halfwords in case of misalignment, since we can't rely on unaligned accesses working before turning the MMU on. No attempt is made to optimise the aligned case, since the number of fixups is typically small, and it seems best to keep the code as simple as possible. * Add a rotate in the fixup_smp code in order to support CPU_BIG_ENDIAN, as suggested by Nicolas Pitre. * Add an assembly-time sanity-check to ALT_UP() to ensure that the content really is the right size (4 bytes). (No check is done for ALT_SMP(). Possibly, this could be fixed by splitting the two uses ot ALT_SMP() (ALT_SMP...SMP_UP versus ALT_SMP...SMP_UP_B) into two macros. In the first case, ALT_SMP needs to expand to >= 4 bytes, not == 4.) * smp_mpidr.h (which implements ALT_SMP()/ALT_UP() manually due to macro limitations) has not been modified: the affected instruction (mov) has no 16-bit encoding, so the correct instruction size is satisfied in this case. * A "mode" parameter has been added to smp_dmb: smp_dmb arm @ assumes 4-byte instructions (for ARM code, e.g. kuser) smp_dmb @ uses W() to ensure 4-byte instructions for ALT_SMP() This avoids assembly failures due to use of W() inside smp_dmb, when assembling pure-ARM code in the vectors page. There might be a better way to achieve this. * Kconfig: make SMP_ON_UP depend on (!THUMB2_KERNEL || !BIG_ENDIAN) i.e., THUMB2_KERNEL is now supported, but only if !BIG_ENDIAN (The fixup code for Thumb-2 currently assumes little-endian order.) Tested using a single generic realview kernel on: ARM RealView PB-A8 (CONFIG_THUMB2_KERNEL={n,y}) ARM RealView PBX-A9 (SMP) Signed-off-by: Dave Martin <dave.martin@linaro.org> Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-12-01 15:39:23 +01:00
ARM: 6516/1: Allow SMP_ON_UP to work with Thumb-2 kernels. * __fixup_smp_on_up has been modified with support for the THUMB2_KERNEL case. For THUMB2_KERNEL only, fixups are split into halfwords in case of misalignment, since we can't rely on unaligned accesses working before turning the MMU on. No attempt is made to optimise the aligned case, since the number of fixups is typically small, and it seems best to keep the code as simple as possible. * Add a rotate in the fixup_smp code in order to support CPU_BIG_ENDIAN, as suggested by Nicolas Pitre. * Add an assembly-time sanity-check to ALT_UP() to ensure that the content really is the right size (4 bytes). (No check is done for ALT_SMP(). Possibly, this could be fixed by splitting the two uses ot ALT_SMP() (ALT_SMP...SMP_UP versus ALT_SMP...SMP_UP_B) into two macros. In the first case, ALT_SMP needs to expand to >= 4 bytes, not == 4.) * smp_mpidr.h (which implements ALT_SMP()/ALT_UP() manually due to macro limitations) has not been modified: the affected instruction (mov) has no 16-bit encoding, so the correct instruction size is satisfied in this case. * A "mode" parameter has been added to smp_dmb: smp_dmb arm @ assumes 4-byte instructions (for ARM code, e.g. kuser) smp_dmb @ uses W() to ensure 4-byte instructions for ALT_SMP() This avoids assembly failures due to use of W() inside smp_dmb, when assembling pure-ARM code in the vectors page. There might be a better way to achieve this. * Kconfig: make SMP_ON_UP depend on (!THUMB2_KERNEL || !BIG_ENDIAN) i.e., THUMB2_KERNEL is now supported, but only if !BIG_ENDIAN (The fixup code for Thumb-2 currently assumes little-endian order.) Tested using a single generic realview kernel on: ARM RealView PB-A8 (CONFIG_THUMB2_KERNEL={n,y}) ARM RealView PBX-A9 (SMP) Signed-off-by: Dave Martin <dave.martin@linaro.org> Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-12-01 15:39:23 +01:00
ARM: 6516/1: Allow SMP_ON_UP to work with Thumb-2 kernels. * __fixup_smp_on_up has been modified with support for the THUMB2_KERNEL case. For THUMB2_KERNEL only, fixups are split into halfwords in case of misalignment, since we can't rely on unaligned accesses working before turning the MMU on. No attempt is made to optimise the aligned case, since the number of fixups is typically small, and it seems best to keep the code as simple as possible. * Add a rotate in the fixup_smp code in order to support CPU_BIG_ENDIAN, as suggested by Nicolas Pitre. * Add an assembly-time sanity-check to ALT_UP() to ensure that the content really is the right size (4 bytes). (No check is done for ALT_SMP(). Possibly, this could be fixed by splitting the two uses ot ALT_SMP() (ALT_SMP...SMP_UP versus ALT_SMP...SMP_UP_B) into two macros. In the first case, ALT_SMP needs to expand to >= 4 bytes, not == 4.) * smp_mpidr.h (which implements ALT_SMP()/ALT_UP() manually due to macro limitations) has not been modified: the affected instruction (mov) has no 16-bit encoding, so the correct instruction size is satisfied in this case. * A "mode" parameter has been added to smp_dmb: smp_dmb arm @ assumes 4-byte instructions (for ARM code, e.g. kuser) smp_dmb @ uses W() to ensure 4-byte instructions for ALT_SMP() This avoids assembly failures due to use of W() inside smp_dmb, when assembling pure-ARM code in the vectors page. There might be a better way to achieve this. * Kconfig: make SMP_ON_UP depend on (!THUMB2_KERNEL || !BIG_ENDIAN) i.e., THUMB2_KERNEL is now supported, but only if !BIG_ENDIAN (The fixup code for Thumb-2 currently assumes little-endian order.) Tested using a single generic realview kernel on: ARM RealView PB-A8 (CONFIG_THUMB2_KERNEL={n,y}) ARM RealView PBX-A9 (SMP) Signed-off-by: Dave Martin <dave.martin@linaro.org> Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-12-01 15:39:23 +01:00
ARM: 6516/1: Allow SMP_ON_UP to work with Thumb-2 kernels. * __fixup_smp_on_up has been modified with support for the THUMB2_KERNEL case. For THUMB2_KERNEL only, fixups are split into halfwords in case of misalignment, since we can't rely on unaligned accesses working before turning the MMU on. No attempt is made to optimise the aligned case, since the number of fixups is typically small, and it seems best to keep the code as simple as possible. * Add a rotate in the fixup_smp code in order to support CPU_BIG_ENDIAN, as suggested by Nicolas Pitre. * Add an assembly-time sanity-check to ALT_UP() to ensure that the content really is the right size (4 bytes). (No check is done for ALT_SMP(). Possibly, this could be fixed by splitting the two uses ot ALT_SMP() (ALT_SMP...SMP_UP versus ALT_SMP...SMP_UP_B) into two macros. In the first case, ALT_SMP needs to expand to >= 4 bytes, not == 4.) * smp_mpidr.h (which implements ALT_SMP()/ALT_UP() manually due to macro limitations) has not been modified: the affected instruction (mov) has no 16-bit encoding, so the correct instruction size is satisfied in this case. * A "mode" parameter has been added to smp_dmb: smp_dmb arm @ assumes 4-byte instructions (for ARM code, e.g. kuser) smp_dmb @ uses W() to ensure 4-byte instructions for ALT_SMP() This avoids assembly failures due to use of W() inside smp_dmb, when assembling pure-ARM code in the vectors page. There might be a better way to achieve this. * Kconfig: make SMP_ON_UP depend on (!THUMB2_KERNEL || !BIG_ENDIAN) i.e., THUMB2_KERNEL is now supported, but only if !BIG_ENDIAN (The fixup code for Thumb-2 currently assumes little-endian order.) Tested using a single generic realview kernel on: ARM RealView PB-A8 (CONFIG_THUMB2_KERNEL={n,y}) ARM RealView PBX-A9 (SMP) Signed-off-by: Dave Martin <dave.martin@linaro.org> Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-12-01 15:39:23 +01:00
ARM: 6516/1: Allow SMP_ON_UP to work with Thumb-2 kernels. * __fixup_smp_on_up has been modified with support for the THUMB2_KERNEL case. For THUMB2_KERNEL only, fixups are split into halfwords in case of misalignment, since we can't rely on unaligned accesses working before turning the MMU on. No attempt is made to optimise the aligned case, since the number of fixups is typically small, and it seems best to keep the code as simple as possible. * Add a rotate in the fixup_smp code in order to support CPU_BIG_ENDIAN, as suggested by Nicolas Pitre. * Add an assembly-time sanity-check to ALT_UP() to ensure that the content really is the right size (4 bytes). (No check is done for ALT_SMP(). Possibly, this could be fixed by splitting the two uses ot ALT_SMP() (ALT_SMP...SMP_UP versus ALT_SMP...SMP_UP_B) into two macros. In the first case, ALT_SMP needs to expand to >= 4 bytes, not == 4.) * smp_mpidr.h (which implements ALT_SMP()/ALT_UP() manually due to macro limitations) has not been modified: the affected instruction (mov) has no 16-bit encoding, so the correct instruction size is satisfied in this case. * A "mode" parameter has been added to smp_dmb: smp_dmb arm @ assumes 4-byte instructions (for ARM code, e.g. kuser) smp_dmb @ uses W() to ensure 4-byte instructions for ALT_SMP() This avoids assembly failures due to use of W() inside smp_dmb, when assembling pure-ARM code in the vectors page. There might be a better way to achieve this. * Kconfig: make SMP_ON_UP depend on (!THUMB2_KERNEL || !BIG_ENDIAN) i.e., THUMB2_KERNEL is now supported, but only if !BIG_ENDIAN (The fixup code for Thumb-2 currently assumes little-endian order.) Tested using a single generic realview kernel on: ARM RealView PB-A8 (CONFIG_THUMB2_KERNEL={n,y}) ARM RealView PBX-A9 (SMP) Signed-off-by: Dave Martin <dave.martin@linaro.org> Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-12-01 15:39:23 +01:00
ARM: 6516/1: Allow SMP_ON_UP to work with Thumb-2 kernels. * __fixup_smp_on_up has been modified with support for the THUMB2_KERNEL case. For THUMB2_KERNEL only, fixups are split into halfwords in case of misalignment, since we can't rely on unaligned accesses working before turning the MMU on. No attempt is made to optimise the aligned case, since the number of fixups is typically small, and it seems best to keep the code as simple as possible. * Add a rotate in the fixup_smp code in order to support CPU_BIG_ENDIAN, as suggested by Nicolas Pitre. * Add an assembly-time sanity-check to ALT_UP() to ensure that the content really is the right size (4 bytes). (No check is done for ALT_SMP(). Possibly, this could be fixed by splitting the two uses ot ALT_SMP() (ALT_SMP...SMP_UP versus ALT_SMP...SMP_UP_B) into two macros. In the first case, ALT_SMP needs to expand to >= 4 bytes, not == 4.) * smp_mpidr.h (which implements ALT_SMP()/ALT_UP() manually due to macro limitations) has not been modified: the affected instruction (mov) has no 16-bit encoding, so the correct instruction size is satisfied in this case. * A "mode" parameter has been added to smp_dmb: smp_dmb arm @ assumes 4-byte instructions (for ARM code, e.g. kuser) smp_dmb @ uses W() to ensure 4-byte instructions for ALT_SMP() This avoids assembly failures due to use of W() inside smp_dmb, when assembling pure-ARM code in the vectors page. There might be a better way to achieve this. * Kconfig: make SMP_ON_UP depend on (!THUMB2_KERNEL || !BIG_ENDIAN) i.e., THUMB2_KERNEL is now supported, but only if !BIG_ENDIAN (The fixup code for Thumb-2 currently assumes little-endian order.) Tested using a single generic realview kernel on: ARM RealView PB-A8 (CONFIG_THUMB2_KERNEL={n,y}) ARM RealView PBX-A9 (SMP) Signed-off-by: Dave Martin <dave.martin@linaro.org> Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-12-01 15:39:23 +01:00
ARM: 6516/1: Allow SMP_ON_UP to work with Thumb-2 kernels. * __fixup_smp_on_up has been modified with support for the THUMB2_KERNEL case. For THUMB2_KERNEL only, fixups are split into halfwords in case of misalignment, since we can't rely on unaligned accesses working before turning the MMU on. No attempt is made to optimise the aligned case, since the number of fixups is typically small, and it seems best to keep the code as simple as possible. * Add a rotate in the fixup_smp code in order to support CPU_BIG_ENDIAN, as suggested by Nicolas Pitre. * Add an assembly-time sanity-check to ALT_UP() to ensure that the content really is the right size (4 bytes). (No check is done for ALT_SMP(). Possibly, this could be fixed by splitting the two uses ot ALT_SMP() (ALT_SMP...SMP_UP versus ALT_SMP...SMP_UP_B) into two macros. In the first case, ALT_SMP needs to expand to >= 4 bytes, not == 4.) * smp_mpidr.h (which implements ALT_SMP()/ALT_UP() manually due to macro limitations) has not been modified: the affected instruction (mov) has no 16-bit encoding, so the correct instruction size is satisfied in this case. * A "mode" parameter has been added to smp_dmb: smp_dmb arm @ assumes 4-byte instructions (for ARM code, e.g. kuser) smp_dmb @ uses W() to ensure 4-byte instructions for ALT_SMP() This avoids assembly failures due to use of W() inside smp_dmb, when assembling pure-ARM code in the vectors page. There might be a better way to achieve this. * Kconfig: make SMP_ON_UP depend on (!THUMB2_KERNEL || !BIG_ENDIAN) i.e., THUMB2_KERNEL is now supported, but only if !BIG_ENDIAN (The fixup code for Thumb-2 currently assumes little-endian order.) Tested using a single generic realview kernel on: ARM RealView PB-A8 (CONFIG_THUMB2_KERNEL={n,y}) ARM RealView PBX-A9 (SMP) Signed-off-by: Dave Martin <dave.martin@linaro.org> Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-12-01 15:39:23 +01:00
ARM: convert all "mov.* pc, reg" to "bx reg" for ARMv6+ ARMv6 and greater introduced a new instruction ("bx") which can be used to return from function calls. Recent CPUs perform better when the "bx lr" instruction is used rather than the "mov pc, lr" instruction, and this sequence is strongly recommended to be used by the ARM architecture manual (section A.4.1.1). We provide a new macro "ret" with all its variants for the condition code which will resolve to the appropriate instruction. Rather than doing this piecemeal, and miss some instances, change all the "mov pc" instances to use the new macro, with the exception of the "movs" instruction and the kprobes code. This allows us to detect the "mov pc, lr" case and fix it up - and also gives us the possibility of deploying this for other registers depending on the CPU selection. Reported-by: Will Deacon <will.deacon@arm.com> Tested-by: Stephen Warren <swarren@nvidia.com> # Tegra Jetson TK1 Tested-by: Robert Jarzmik <robert.jarzmik@free.fr> # mioa701_bootresume.S Tested-by: Andrew Lunn <andrew@lunn.ch> # Kirkwood Tested-by: Shawn Guo <shawn.guo@freescale.com> Tested-by: Tony Lindgren <tony@atomide.com> # OMAPs Tested-by: Gregory CLEMENT <gregory.clement@free-electrons.com> # Armada XP, 375, 385 Acked-by: Sekhar Nori <nsekhar@ti.com> # DaVinci Acked-by: Christoffer Dall <christoffer.dall@linaro.org> # kvm/hyp Acked-by: Haojian Zhuang <haojian.zhuang@gmail.com> # PXA3xx Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> # Xen Tested-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> # ARMv7M Tested-by: Simon Horman <horms+renesas@verge.net.au> # Shmobile Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2014-06-30 16:29:12 +01:00
ARM: assembler: introduce adr_l, ldr_l and str_l macros Like arm64, ARM supports position independent code sequences that produce symbol references with a greater reach than the ordinary adr/ldr instructions. Since on ARM, the adrl pseudo-instruction is only supported in ARM mode (and not at all when using Clang), having a adr_l macro like we do on arm64 is useful, and increases symmetry as well. Currently, we use open coded instruction sequences involving literals and arithmetic operations. Instead, we can use movw/movt pairs on v7 CPUs, circumventing the D-cache entirely. E.g., on v7+ CPUs, we can emit a PC-relative reference as follows: movw <reg>, #:lower16:<sym> - (1f + 8) movt <reg>, #:upper16:<sym> - (1f + 8) 1: add <reg>, <reg>, pc For older CPUs, we can emit the literal into a subsection, allowing it to be emitted out of line while retaining the ability to perform arithmetic on label offsets. E.g., on pre-v7 CPUs, we can emit a PC-relative reference as follows: ldr <reg>, 2f 1: add <reg>, <reg>, pc .subsection 1 2: .long <sym> - (1b + 8) .previous This is allowed by the assembler because, unlike ordinary sections, subsections are combined into a single section in the object file, and so the label references are not true cross-section references that are visible as relocations. (Subsections have been available in binutils since 2004 at least, so they should not cause any issues with older toolchains.) So use the above to implement the macros mov_l, adr_l, ldr_l and str_l, all of which will use movw/movt pairs on v7 and later CPUs, and use PC-relative literals otherwise. Reviewed-by: Nicolas Pitre <nico@fluxnic.net> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-09-14 11:23:39 +03:00
ARM: assembler: introduce adr_l, ldr_l and str_l macros Like arm64, ARM supports position independent code sequences that produce symbol references with a greater reach than the ordinary adr/ldr instructions. Since on ARM, the adrl pseudo-instruction is only supported in ARM mode (and not at all when using Clang), having a adr_l macro like we do on arm64 is useful, and increases symmetry as well. Currently, we use open coded instruction sequences involving literals and arithmetic operations. Instead, we can use movw/movt pairs on v7 CPUs, circumventing the D-cache entirely. E.g., on v7+ CPUs, we can emit a PC-relative reference as follows: movw <reg>, #:lower16:<sym> - (1f + 8) movt <reg>, #:upper16:<sym> - (1f + 8) 1: add <reg>, <reg>, pc For older CPUs, we can emit the literal into a subsection, allowing it to be emitted out of line while retaining the ability to perform arithmetic on label offsets. E.g., on pre-v7 CPUs, we can emit a PC-relative reference as follows: ldr <reg>, 2f 1: add <reg>, <reg>, pc .subsection 1 2: .long <sym> - (1b + 8) .previous This is allowed by the assembler because, unlike ordinary sections, subsections are combined into a single section in the object file, and so the label references are not true cross-section references that are visible as relocations. (Subsections have been available in binutils since 2004 at least, so they should not cause any issues with older toolchains.) So use the above to implement the macros mov_l, adr_l, ldr_l and str_l, all of which will use movw/movt pairs on v7 and later CPUs, and use PC-relative literals otherwise. Reviewed-by: Nicolas Pitre <nico@fluxnic.net> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-09-14 11:23:39 +03:00
ARM: assembler: introduce adr_l, ldr_l and str_l macros Like arm64, ARM supports position independent code sequences that produce symbol references with a greater reach than the ordinary adr/ldr instructions. Since on ARM, the adrl pseudo-instruction is only supported in ARM mode (and not at all when using Clang), having a adr_l macro like we do on arm64 is useful, and increases symmetry as well. Currently, we use open coded instruction sequences involving literals and arithmetic operations. Instead, we can use movw/movt pairs on v7 CPUs, circumventing the D-cache entirely. E.g., on v7+ CPUs, we can emit a PC-relative reference as follows: movw <reg>, #:lower16:<sym> - (1f + 8) movt <reg>, #:upper16:<sym> - (1f + 8) 1: add <reg>, <reg>, pc For older CPUs, we can emit the literal into a subsection, allowing it to be emitted out of line while retaining the ability to perform arithmetic on label offsets. E.g., on pre-v7 CPUs, we can emit a PC-relative reference as follows: ldr <reg>, 2f 1: add <reg>, <reg>, pc .subsection 1 2: .long <sym> - (1b + 8) .previous This is allowed by the assembler because, unlike ordinary sections, subsections are combined into a single section in the object file, and so the label references are not true cross-section references that are visible as relocations. (Subsections have been available in binutils since 2004 at least, so they should not cause any issues with older toolchains.) So use the above to implement the macros mov_l, adr_l, ldr_l and str_l, all of which will use movw/movt pairs on v7 and later CPUs, and use PC-relative literals otherwise. Reviewed-by: Nicolas Pitre <nico@fluxnic.net> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-09-14 11:23:39 +03:00
ARM: assembler: introduce adr_l, ldr_l and str_l macros Like arm64, ARM supports position independent code sequences that produce symbol references with a greater reach than the ordinary adr/ldr instructions. Since on ARM, the adrl pseudo-instruction is only supported in ARM mode (and not at all when using Clang), having a adr_l macro like we do on arm64 is useful, and increases symmetry as well. Currently, we use open coded instruction sequences involving literals and arithmetic operations. Instead, we can use movw/movt pairs on v7 CPUs, circumventing the D-cache entirely. E.g., on v7+ CPUs, we can emit a PC-relative reference as follows: movw <reg>, #:lower16:<sym> - (1f + 8) movt <reg>, #:upper16:<sym> - (1f + 8) 1: add <reg>, <reg>, pc For older CPUs, we can emit the literal into a subsection, allowing it to be emitted out of line while retaining the ability to perform arithmetic on label offsets. E.g., on pre-v7 CPUs, we can emit a PC-relative reference as follows: ldr <reg>, 2f 1: add <reg>, <reg>, pc .subsection 1 2: .long <sym> - (1b + 8) .previous This is allowed by the assembler because, unlike ordinary sections, subsections are combined into a single section in the object file, and so the label references are not true cross-section references that are visible as relocations. (Subsections have been available in binutils since 2004 at least, so they should not cause any issues with older toolchains.) So use the above to implement the macros mov_l, adr_l, ldr_l and str_l, all of which will use movw/movt pairs on v7 and later CPUs, and use PC-relative literals otherwise. Reviewed-by: Nicolas Pitre <nico@fluxnic.net> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-09-14 11:23:39 +03:00