From 4a71d6d32e59ecf02c246037198882e59894db3d Mon Sep 17 00:00:00 2001 From: Joe Komlodi Date: Mon, 13 Jun 2022 14:05:48 +0200 Subject: [PATCH] hw/registerfields: Add shared fields macros MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Occasionally a peripheral will have different operating modes, where the MMIO layout changes, but some of the register fields have the same offsets and behaviors. To help support this, we add SHARED_FIELD_XX macros that create SHIFT, LENGTH, and MASK macros for the fields that are shared across registers, and accessors for these fields. An example use may look as follows: There is a peripheral with registers REG_MODE1 and REG_MODE2 at different addreses, and both have a field FIELD1 initialized by SHARED_FIELD(). Depending on what mode the peripheral is operating in, the user could extract FIELD1 via SHARED_ARRAY_FIELD_EX32(s->regs, R_REG_MODE1, FIELD1) or SHARED_ARRAY_FIELD_EX32(s->regs, R_REG_MODE2, FIELD1) Signed-off-by: Joe Komlodi Change-Id: Id3dc53e7d2f8741c95697cbae69a81bb699fa3cb Message-Id: <20220331043248.2237838-2-komlodi@google.com> Signed-off-by: Cédric Le Goater --- include/hw/registerfields.h | 70 +++++++++++++++++++++++++++++++++++++ 1 file changed, 70 insertions(+) diff --git a/include/hw/registerfields.h b/include/hw/registerfields.h index 3a88e135d0..1330ca77de 100644 --- a/include/hw/registerfields.h +++ b/include/hw/registerfields.h @@ -154,4 +154,74 @@ #define ARRAY_FIELD_DP64(regs, reg, field, val) \ (regs)[R_ ## reg] = FIELD_DP64((regs)[R_ ## reg], reg, field, val); + +/* + * These macros can be used for defining and extracting fields that have the + * same bit position across multiple registers. + */ + +/* Define shared SHIFT, LENGTH, and MASK constants */ +#define SHARED_FIELD(name, shift, length) \ + enum { name ## _ ## SHIFT = (shift)}; \ + enum { name ## _ ## LENGTH = (length)}; \ + enum { name ## _ ## MASK = MAKE_64BIT_MASK(shift, length)}; + +/* Extract a shared field */ +#define SHARED_FIELD_EX8(storage, field) \ + extract8((storage), field ## _SHIFT, field ## _LENGTH) + +#define SHARED_FIELD_EX16(storage, field) \ + extract16((storage), field ## _SHIFT, field ## _LENGTH) + +#define SHARED_FIELD_EX32(storage, field) \ + extract32((storage), field ## _SHIFT, field ## _LENGTH) + +#define SHARED_FIELD_EX64(storage, field) \ + extract64((storage), field ## _SHIFT, field ## _LENGTH) + +/* Extract a shared field from a register array */ +#define SHARED_ARRAY_FIELD_EX32(regs, offset, field) \ + SHARED_FIELD_EX32((regs)[(offset)], field) +#define SHARED_ARRAY_FIELD_EX64(regs, offset, field) \ + SHARED_FIELD_EX64((regs)[(offset)], field) + +/* Deposit a shared field */ +#define SHARED_FIELD_DP8(storage, field, val) ({ \ + struct { \ + unsigned int v:field ## _LENGTH; \ + } _v = { .v = val }; \ + uint8_t _d; \ + _d = deposit32((storage), field ## _SHIFT, field ## _LENGTH, _v.v); \ + _d; }) + +#define SHARED_FIELD_DP16(storage, field, val) ({ \ + struct { \ + unsigned int v:field ## _LENGTH; \ + } _v = { .v = val }; \ + uint16_t _d; \ + _d = deposit32((storage), field ## _SHIFT, field ## _LENGTH, _v.v); \ + _d; }) + +#define SHARED_FIELD_DP32(storage, field, val) ({ \ + struct { \ + unsigned int v:field ## _LENGTH; \ + } _v = { .v = val }; \ + uint32_t _d; \ + _d = deposit32((storage), field ## _SHIFT, field ## _LENGTH, _v.v); \ + _d; }) + +#define SHARED_FIELD_DP64(storage, field, val) ({ \ + struct { \ + uint64_t v:field ## _LENGTH; \ + } _v = { .v = val }; \ + uint64_t _d; \ + _d = deposit64((storage), field ## _SHIFT, field ## _LENGTH, _v.v); \ + _d; }) + +/* Deposit a shared field to a register array */ +#define SHARED_ARRAY_FIELD_DP32(regs, offset, field, val) \ + (regs)[(offset)] = SHARED_FIELD_DP32((regs)[(offset)], field, val); +#define SHARED_ARRAY_FIELD_DP64(regs, offset, field, val) \ + (regs)[(offset)] = SHARED_FIELD_DP64((regs)[(offset)], field, val); + #endif