r += "\n#endif\n"
return r
-def _get_rw_functions_c(reg_name, reg_base, nwords, busword, alignment, read_only, with_access_functions):
+def _get_rw_functions_c(reg_name, reg_base, nwords, busword, read_only, with_access_functions):
r = ""
- r += "#define CSR_"+reg_name.upper()+"_ADDR "+hex(reg_base)+"L\n"
- r += "#define CSR_"+reg_name.upper()+"_SIZE "+str(nwords)+"\n"
+ addr_str = "CSR_{}_ADDR".format(reg_name.upper())
+ size_str = "CSR_{}_SIZE".format(reg_name.upper())
+ r += "#define {} {}L\n".format(addr_str, hex(reg_base))
+ r += "#define {} {}\n".format(size_str, nwords)
- size = nwords*busword
- if size > 64:
+ size = nwords*busword//8
+ if size > 8:
+ # FIXME: maybe implement some "memcpy-like" semantics for larger blobs?
return r
- elif size > 32:
- ctype = "unsigned long long int"
- elif size > 16:
- ctype = "unsigned int"
- elif size > 8:
- ctype = "unsigned short int"
+ elif size > 4:
+ ctype = "uint64_t"
+ elif size > 2:
+ ctype = "uint32_t"
+ elif size > 1:
+ ctype = "uint16_t"
else:
- ctype = "unsigned char"
+ ctype = "uint8_t"
if with_access_functions:
- r += "static inline "+ctype+" "+reg_name+"_read(void) {\n"
- if size > 1:
- r += "\t"+ctype+" r = csr_readl("+hex(reg_base)+"L);\n"
- for byte in range(1, nwords):
- r += "\tr <<= "+str(busword)+";\n\tr |= csr_readl("+hex(reg_base+alignment//8*byte)+"L);\n"
- r += "\treturn r;\n}\n"
- else:
- r += "\treturn csr_readl("+hex(reg_base)+"L);\n}\n"
+ r += "static inline {} {}_read(void) {{\n".format(ctype, reg_name)
+ r += "\treturn _csr_rd((unsigned long *){}, {});\n}}\n".format(addr_str, size)
if not read_only:
- r += "static inline void "+reg_name+"_write("+ctype+" value) {\n"
- for word in range(nwords):
- shift = (nwords-word-1)*busword
- if shift:
- value_shifted = "value >> "+str(shift)
- else:
- value_shifted = "value"
- r += "\tcsr_writel("+value_shifted+", "+hex(reg_base+alignment//8*word)+"L);\n"
- r += "}\n"
+ r += "static inline void {}_write({} v) {{\n".format(reg_name, ctype)
+ r += "\t_csr_wr((unsigned long *){}, v, {});\n}}\n".format(addr_str, size)
return r
if with_access_functions:
r += "#include <stdint.h>\n"
r += "#ifdef CSR_ACCESSORS_DEFINED\n"
- r += "extern void csr_writeb(uint8_t value, unsigned long addr);\n"
- r += "extern uint8_t csr_readb(unsigned long addr);\n"
- r += "extern void csr_writew(uint16_t value, unsigned long addr);\n"
- r += "extern uint16_t csr_readw(unsigned long addr);\n"
- r += "extern void csr_writel(uint32_t value, unsigned long addr);\n"
- r += "extern uint32_t csr_readl(unsigned long addr);\n"
+ r += "extern void csr_wr_uint8(uint8_t v, unsigned long a);\n"
+ r += "extern void csr_wr_uint16(uint16_t v, unsigned long a);\n"
+ r += "extern void csr_wr_uint32(uint32_t v, unsigned long a);\n"
+ r += "extern void csr_wr_uint64(uint64_t v, unsigned long a);\n"
+ r += "extern uint8_t csr_rd_uint8(unsigned long a);\n"
+ r += "extern uint16_t csr_rd_uint16(unsigned long a);\n"
+ r += "extern uint32_t csr_rd_uint32(unsigned long a);\n"
+ r += "extern uint64_t csr_rd_uint64(unsigned long a);\n"
r += "#else /* ! CSR_ACCESSORS_DEFINED */\n"
r += "#include <hw/common.h>\n"
r += "#endif /* ! CSR_ACCESSORS_DEFINED */\n"
if not isinstance(region.obj, Memory):
for csr in region.obj:
nr = (csr.size + region.busword - 1)//region.busword
- r += _get_rw_functions_c(name + "_" + csr.name, origin, nr, region.busword, alignment,
+ r += _get_rw_functions_c(name + "_" + csr.name, origin, nr, region.busword,
isinstance(csr, CSRStatus), with_access_functions)
origin += alignment//8*nr
if hasattr(csr, "fields"):
#include <stdint.h>
/* To overwrite CSR accessors, define extern, non-inlined versions
- * of csr_read[bwl]() and csr_write[bwl](), and define
- * CSR_ACCESSORS_DEFINED.
+ * of csr_rd_uint[8|16|32|64]() and csr_wr_uint[8|16|32|64](), and
+ * define CSR_ACCESSORS_DEFINED.
*/
#ifndef CSR_ACCESSORS_DEFINED
#ifdef __ASSEMBLER__
#define MMPTR(x) x
#else /* ! __ASSEMBLER__ */
-#define MMPTR(x) (*((volatile unsigned long *)(x)))
-static inline void csr_writeb(uint8_t value, unsigned long addr)
+/* CSRs are stored in subregister slices of CONFIG_CSR_DATA_WIDTH (native
+ * endianness), with the least significant slice at the lowest aligned
+ * (base) address. */
+
+#include <generated/soc.h>
+#if !defined(CONFIG_CSR_ALIGNMENT) || !defined(CONFIG_CSR_DATA_WIDTH)
+#error csr alignment and data-width MUST be set before including this file!
+#endif
+
+#if CONFIG_CSR_DATA_WIDTH > CONFIG_CSR_ALIGNMENT
+#error invalid CONFIG_CSR_DATA_WIDTH (must not exceed CONFIG_CSR_ALIGNMENT)!
+#endif
+
+/* FIXME: preprocessor can't evaluate 'sizeof()' operator, is there a better
+ * way to implement the following assertion?
+ * #if sizeof(unsigned long) != CONFIG_CSR_ALIGNMENT/8
+ * #error invalid CONFIG_CSR_ALIGNMENT (must match native CPU word size)!
+ * #endif
+ */
+
+/* CSR data width (subregister width) in bytes, for direct comparson to sizeof() */
+#define CSR_DW_BYTES (CONFIG_CSR_DATA_WIDTH/8)
+
+/* CSR subregisters are embedded inside native CPU word aligned locations: */
+#define MMPTR(a) (*((volatile unsigned long *)(a)))
+
+/* Number of subregs required for various total byte sizes, by subreg width:
+ * NOTE: 1, 2, 4, and 8 bytes represent uint[8|16|32|64]_t C types; However,
+ * CSRs of intermediate byte sizes (24, 40, 48, and 56) are NOT padded
+ * (with extra unallocated subregisters) to the next valid C type!
+ * +-----+-----------------+
+ * | csr | bytes |
+ * | _dw | 1 2 3 4 5 6 7 8 |
+ * | |-----=---=-=-=---|
+ * | 1 | 1 2 3 4 5 6 7 8 |
+ * | 2 | 1 1 2 2 3 3 4 4 |
+ * | 4 | 1 1 1 1 2 2 2 2 |
+ * | 8 | 1 1 1 1 1 1 1 1 |
+ * +-----+-----------------+ */
+static inline int num_subregs(int csr_bytes)
{
- *((volatile uint8_t *)addr) = value;
+ return (csr_bytes - 1) / CSR_DW_BYTES + 1;
}
-static inline uint8_t csr_readb(unsigned long addr)
+/* Read a CSR of size 'csr_bytes' located at address 'a'. */
+static inline uint64_t _csr_rd(unsigned long *a, int csr_bytes)
+{
+ uint64_t r = a[0];
+ for (int i = 1; i < num_subregs(csr_bytes); i++) {
+ r <<= CONFIG_CSR_DATA_WIDTH;
+ r |= a[i];
+ }
+ return r;
+}
+
+/* Write value 'v' to a CSR of size 'csr_bytes' located at address 'a'. */
+static inline void _csr_wr(unsigned long *a, uint64_t v, int csr_bytes)
+{
+ int ns = num_subregs(csr_bytes);
+ for (int i = 0; i < ns; i++)
+ a[i] = v >> (CONFIG_CSR_DATA_WIDTH * (ns - 1 - i));
+}
+
+// FIXME: - should we provide 24, 40, 48, and 56 bit csr_[rd|wr] methods?
+
+static inline uint8_t csr_rd_uint8(unsigned long a)
{
- return *(volatile uint8_t *)addr;
+ return _csr_rd((unsigned long *)a, sizeof(uint8_t));
}
-static inline void csr_writew(uint16_t value, unsigned long addr)
+static inline void csr_wr_uint8(uint8_t v, unsigned long a)
{
- *((volatile uint16_t *)addr) = value;
+ _csr_wr((unsigned long *)a, v, sizeof(uint8_t));
}
-static inline uint16_t csr_readw(unsigned long addr)
+static inline uint16_t csr_rd_uint16(unsigned long a)
{
- return *(volatile uint16_t *)addr;
+ return _csr_rd((unsigned long *)a, sizeof(uint16_t));
}
-static inline void csr_writel(uint32_t value, unsigned long addr)
+static inline void csr_wr_uint16(uint16_t v, unsigned long a)
{
- *((volatile uint32_t *)addr) = value;
+ _csr_wr((unsigned long *)a, v, sizeof(uint16_t));
}
-static inline uint32_t csr_readl(unsigned long addr)
+static inline uint32_t csr_rd_uint32(unsigned long a)
{
- return *(volatile uint32_t *)addr;
+ return _csr_rd((unsigned long *)a, sizeof(uint32_t));
}
+
+static inline void csr_wr_uint32(uint32_t v, unsigned long a)
+{
+ _csr_wr((unsigned long *)a, v, sizeof(uint32_t));
+}
+
+static inline uint64_t csr_rd_uint64(unsigned long a)
+{
+ return _csr_rd((unsigned long *)a, sizeof(uint64_t));
+}
+
+static inline void csr_wr_uint64(uint64_t v, unsigned long a)
+{
+ _csr_wr((unsigned long *)a, v, sizeof(uint64_t));
+}
+
+/* Read a CSR located at address 'a' into an array 'buf' of 'cnt' elements.
+ *
+ * NOTE: Since CSR_DW_BYTES is a constant here, we might be tempted to further
+ * optimize things by leaving out one or the other of the if() branches below,
+ * depending on each unsigned type width;
+ * However, this code is also meant to serve as a reference for how CSRs are
+ * to be manipulated by other programs (e.g., an OS kernel), which may benefit
+ * from dynamically handling multiple possible CSR subregister data widths
+ * (e.g., by passing a value in through the Device Tree).
+ * Ultimately, if CSR_DW_BYTES is indeed a constant, the compiler should be
+ * able to determine on its own whether it can automatically optimize away one
+ * of the if() branches! */
+#define _csr_rd_buf(a, buf, cnt) \
+{ \
+ int i, j, nsubs, n_sub_elem; \
+ unsigned long *addr = (unsigned long *)(a); \
+ uint64_t r; \
+ if (sizeof(buf[0]) >= CSR_DW_BYTES) { \
+ /* one or more subregisters per element */ \
+ for (i = 0; i < cnt; i++) { \
+ buf[i] = _csr_rd(addr, sizeof(buf[0])); \
+ addr += num_subregs(sizeof(buf[0])); \
+ } \
+ } else { \
+ /* multiple elements per subregister (2, 4, or 8) */ \
+ nsubs = num_subregs(sizeof(buf[0]) * cnt); \
+ n_sub_elem = CSR_DW_BYTES / sizeof(buf[0]); \
+ for (i = 0; i < nsubs; i++) { \
+ r = addr[i]; \
+ for (j = n_sub_elem - 1; j >= 0; j--) { \
+ if (i * n_sub_elem + j < cnt) \
+ buf[i * n_sub_elem + j] = r; \
+ r >>= sizeof(buf[0]) * 8; \
+ } \
+ } \
+ } \
+}
+
+/* Write an array 'buf' of 'cnt' elements to a CSR located at address 'a'.
+ *
+ * NOTE: The same optimization considerations apply here as with _csr_rd_buf()
+ * above.
+ */
+#define _csr_wr_buf(a, buf, cnt) \
+{ \
+ int i, j, nsubs, n_sub_elem; \
+ unsigned long *addr = (unsigned long *)(a); \
+ uint64_t v; \
+ if (sizeof(buf[0]) >= CSR_DW_BYTES) { \
+ /* one or more subregisters per element */ \
+ for (i = 0; i < cnt; i++) { \
+ _csr_wr(addr, buf[i], sizeof(buf[0])); \
+ addr += num_subregs(sizeof(buf[0])); \
+ } \
+ } else { \
+ /* multiple elements per subregister (2, 4, or 8) */ \
+ nsubs = num_subregs(sizeof(buf[0]) * cnt); \
+ n_sub_elem = CSR_DW_BYTES / sizeof(buf[0]); \
+ for (i = 0; i < nsubs; i++) { \
+ v = buf[i * n_sub_elem + 0]; \
+ for (j = 1; j < n_sub_elem; j++) { \
+ if (i * n_sub_elem + j == cnt) \
+ break; \
+ v <<= sizeof(buf[0]) * 8; \
+ v |= buf[i * n_sub_elem + j]; \
+ } \
+ addr[i] = v; \
+ } \
+ } \
+}
+
+static inline void csr_rd_buf_uint8(unsigned long a, uint8_t *buf, int cnt)
+{
+ _csr_rd_buf(a, buf, cnt);
+}
+
+static inline void csr_wr_buf_uint8(unsigned long a,
+ const uint8_t *buf, int cnt)
+{
+ _csr_wr_buf(a, buf, cnt);
+}
+
+static inline void csr_rd_buf_uint16(unsigned long a, uint16_t *buf, int cnt)
+{
+ _csr_rd_buf(a, buf, cnt);
+}
+
+static inline void csr_wr_buf_uint16(unsigned long a,
+ const uint16_t *buf, int cnt)
+{
+ _csr_wr_buf(a, buf, cnt);
+}
+
+static inline void csr_rd_buf_uint32(unsigned long a, uint32_t *buf, int cnt)
+{
+ _csr_rd_buf(a, buf, cnt);
+}
+
+static inline void csr_wr_buf_uint32(unsigned long a,
+ const uint32_t *buf, int cnt)
+{
+ _csr_wr_buf(a, buf, cnt);
+}
+
+/* NOTE: the macros' "else" branch is unreachable, no need to be warned
+ * about a >= 64bit left shift! */
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wshift-count-overflow"
+static inline void csr_rd_buf_uint64(unsigned long a, uint64_t *buf, int cnt)
+{
+ _csr_rd_buf(a, buf, cnt);
+}
+
+static inline void csr_wr_buf_uint64(unsigned long a,
+ const uint64_t *buf, int cnt)
+{
+ _csr_wr_buf(a, buf, cnt);
+}
+#pragma GCC diagnostic pop
+
#endif /* ! __ASSEMBLER__ */
#endif /* ! CSR_ACCESSORS_DEFINED */
projects / litex.git / commitdiff